Professor Klaus Moessner

Teaching

Mobile Applications and Web Services - EEEM042

Operating Systems for Mobile Systems - EEEM024

 

2016/17 projects for UGs and MSc's are available, see more here (only accessible with University login).

 

Offering Final Year and MSc projects in the areas: 

  • IoT and mobile applications:
    • Mobile services design and development (mobile apps, web apps, ...) 
    • Internet of Things experimentation and development (sensing, actuation, knowledge derivation)
    • Location based services
  • 5G System
    • Spectrum sharing and resource scheduling
    • Service provision

 

Contact Me

E-mail:
Phone: 01483 68 3468

Find me on campus
Room: 05 CII 01

Publications

Highlights

  • Francois F, Wang N, Moessner K, Georgoulas S, De Oliveira Schmidt R. (2014) 'Leveraging MPLS backup paths for distributed energy-aware traffic engineering'. IEEE Transactions on Network and Service Management, 11 (2), pp. 235-249.

    Abstract

    Backup paths are usually pre-installed by network operators to protect against single link failures in backbone networks that use multi-protocol label switching. This paper introduces a new scheme called Green Backup Paths (GBP) that intelligently exploits these existing backup paths to perform energy-aware traffic engineering without adversely impacting the primary role of these backup paths of preventing traffic loss upon single link failures. This is in sharp contrast to most existing schemes that tackle energy efficiency and link failure protection separately, resulting in substantially high operational costs. GBP works in an online and distributed fashion, where each router periodically monitors its local traffic conditions and cooperatively determines how to reroute traffic so that the highest number of physical links can go to sleep for energy saving. Furthermore, our approach maintains quality-of-service by restricting the use of long backup paths for failure protection only, and therefore, GBP avoids substantially increased packet delays. GBP was evaluated on the point-of-presence representation of two publicly available network topologies, namely, GÉANT and Abilene, and their real traffic matrices. GBP was able to achieve significant energy saving gains, which are always within 15% of the theoretical upper bound. © 2004-2012 IEEE.

  • Jin Y, Vural S, Gluhak A, Moessner K. (2013) 'Dynamic task allocation in multi-hop multimedia wireless sensor networks with low mobility.'. Sensors (Basel, Switzerland), 13 (10), pp. 13998-14028.
  • Lee H, Vahid S, Moessner K. (2013) 'A survey of radio resource management for spectrum aggregation in LTE-advanced'. IEEE Communications Surveys and Tutorials, 16 (2), pp. 745-760.

    Abstract

    In order to satisfy the requirements of future IMT-Advanced mobile systems, the concept of spectrum aggregation is introduced by 3GPP in its new LTE-Advanced (LTE Rel. 10) standards. While spectrum aggregation allows aggregation of carrier components (CCs) dispersed within and across different bands (intra/inter-band) as well as combination of CCs having different bandwidths, spectrum aggregation is expected to provide a powerful boost to the user throughput in LTE-Advanced (LTE-A). However, introduction of spectrum aggregation or carrier aggregation (CA) as referred to in LTE Rel. 10, has required some changes from the baseline LTE Rel. 8 although each CC in LTE-A remains backward compatible with LTE Rel. 8. This article provides a review of spectrum aggregation techniques, followed by requirements on radio resource management (RRM) functionality in support of CA. On-going research on the different RRM aspects and algorithms to support CA in LTE-Advanced are surveyed. Technical challenges for future research on aggregation in LTE-Advanced systems are also outlined. © 2014 IEEE.

  • Jin Y, Vural S, Gluhak A, Moessner K. (2013) 'Dynamic task allocation in multi-hop multimedia wireless sensor networks with low mobility.'. Sensors (Basel), Switzerland: 13 (10), pp. 13998-14028.

    Abstract

    This paper presents a task allocation-oriented framework to enable efficient in-network processing and cost-effective multi-hop resource sharing for dynamic multi-hop multimedia wireless sensor networks with low node mobility, e.g., pedestrian speeds. The proposed system incorporates a fast task reallocation algorithm to quickly recover from possible network service disruptions, such as node or link failures. An evolutional self-learning mechanism based on a genetic algorithm continuously adapts the system parameters in order to meet the desired application delay requirements, while also achieving a sufficiently long network lifetime. Since the algorithm runtime incurs considerable time delay while updating task assignments, we introduce an adaptive window size to limit the delay periods and ensure an up-to-date solution based on node mobility patterns and device processing capabilities. To the best of our knowledge, this is the first study that yields multi-objective task allocation in a mobile multi-hop wireless environment under dynamic conditions. Simulations are performed in various settings, and the results show considerable performance improvement in extending network lifetime compared to heuristic mechanisms. Furthermore, the proposed framework provides noticeable reduction in the frequency of missing application deadlines.

  • Vural S, Wei D, Moessner K. (2012) 'Survey of Experimental Evaluation Studies for Wireless Mesh Network Deployments in Urban Areas Towards Ubiquitous Internet'. IEEE IEEE Communications Surveys and Tutorials, PP (99), pp. 1-17.

    Abstract

    Establishing wireless networks in urban areas that can provide ubiquitous Internet access to end-users is a central part of the efforts towards defining the Internet of the future. In recent years, Wireless Mesh Network (WMN) backbone infrastructures are proposed as a cost effective technology to provide city-wide Internet access. Studies that evaluate the performance of city-wide mesh network deployments via experiments provide essential information on various challenges of building them. In this survey, we particularly focus on such studies and provide brief conclusions on the problems, benefits, and future research directions of city-wide WMNs.

  • Wei D, Jin Y, Vural S, Moessner K, Tafazolli R. (2011) 'An Energy-efficient Clustering Solution for Wireless Sensor Networks'. IEEE Transactions on Wireless Communications, United Kingdom: PP (99), pp. 1-11.

    Abstract

    Hot spots in a wireless sensor network emerge as locations under heavy traffic load. Nodes in such areas quickly deplete energy resources, leading to disruption in network services. This problem is common for data collection scenarios in which Cluster Heads (CH) have a heavy burden of gathering and relaying information. The relay load on CHs especially intensifies as the distance to the sink decreases. To balance the traffic load and the energy consumption in the network, the CH role should be rotated among all nodes and the cluster sizes should be carefully determined at different parts of the network. This paper proposes a distributed clustering algorithm, Energy-efficient Clustering (EC), that determines suitable cluster sizes depending on the hop distance to the data sink, while achieving approximate equalization of node lifetimes and reduced energy consumption levels. We additionally propose a simple energy-efficient multihop data collection protocol to evaluate the effectiveness of EC and calculate the end-to-end energy consumption of this protocol; yet EC is suitable for any data collection protocol that focuses on energy conservation. Performance results demonstrate that EC extends network lifetime and achieves energy equalization more effectively than two well-known clustering algorithms, HEED and UCR.

  • Moessner K, Georgoulas S. (2011) 'Towards Efficient Protocol Design through Protocol Profiling and Performance Assessment: Using Formal Verification in a Different Context'. Wiley International Journal of Communication Systems, 25 (11)

    Abstract

    The most common use of formal verification methods so far has been in identifying whether livelock and/or deadlock situations can occur during protocol execution, process, or system operation. In this work, we aim to show that an additional equally important and useful application of formal verification methods can be in protocol design in terms of performance-related metrics. This can be achieved by using the methods in a rather different context compared with their traditional use, that is, not only as model checking tools to assess the correctness of a protocol in terms of lack of livelock and deadlock situations but rather as tools capable of building profiles of protocol operations, assessing their performance, and identifying operational patterns and possible bottleneck operations. This process can provide protocol designers with an insight about the protocols' behavior and guide them toward further optimizations. It can also assist network operators and service providers to assess the protocols' relative performance and select the most suitable protocol for specific deployment scenarios. We illustrate these principles by showing how formal verification tools can be applied in this protocol profiling and performance assessment context using some existing protocol implementations in mobile and wireless environments as case studies. Copyright © 2011 John Wiley & Sons, Ltd.

  • Moessner K, Harada H, Sun C, Alemseged Y, Tran H, Noguet D, Sawai R, Sato N. (2011) 'Spectrum sensing for cognitive radio systems: Technical aspects and standardization activities of the IEEE P1900.6 working group'. IEEE Wireless Communications, 18 (1), pp. 30-37.
  • Jin Y, Jin J, Gluhak A, Moessner K, Palaniswami M. (2011) 'An Intelligent Task Allocation Scheme for Multi-hop Wireless Networks'. IEEE Computer Society IEEE Transactions on Parallel and Distributed Systems, 23 (3), pp. 444-451.
  • Kernchen R, Meissner S, Moessner K, Cesar P, Vaishnavi I, Boussard M, Hesselman C. (2010) 'Intelligent Multimedia Presentation in Ubiquitous Multidevice Scenarios'. IEEE COMPUTER SOC IEEE MULTIMEDIA, 17 (2), pp. 52-62.
  • Arshad K, Imran MA, Moessener K. (2010) 'Collaborative Spectrum Sensing Optimisation Algorithms for Cognitive Radio Networks'. Hindawi Publishing Corporation International Journal of Digital Multimedia Broadcasting, 2010 Article number Article ID 424036

    Abstract

    The main challenge for a cognitive radio is to detect the existence of primary users reliably in order to minimise the interference to licensed communications. Hence, spectrum sensing is a most important requirement of a cognitive radio. However, due to the channel uncertainties, local observations are not reliable and collaboration among users is required. Selection of fusion rule at a common receiver has a direct impact on the overall spectrum sensing performance. In this paper, optimisation of collaborative spectrum sensing in terms of optimum decision fusion is studied for hard and soft decision combining. It is concluded that for optimum fusion, the fusion centre must incorporate signal-to-noise ratio values of cognitive users and the channel conditions. A genetic algorithm-based weighted optimisation strategy is presented for the case of soft decision combining. Numerical results show that the proposed optimised collaborative spectrum sensing schemes give better spectrum sensing performance.

  • Prammanee S, Moessner K. (2008) 'Mobile Multimodality: A Theoretical Approach to Facilitate Virtual Device Environments'. SPRINGER MOBILE NETWORKS & APPLICATIONS, 13 (6), pp. 569-582.
  • Rodriguez V, Moessner K, Tafazolli R. (2006) 'Market driven dynamic spectrum allocation over space and time among radio-access networks: DVB-T and B3G CDMA with heterogeneous terminals'. SPRINGER MOBILE NETWORKS & APPLICATIONS, 11 (6), pp. 847-860.

Journal articles

  • Pozza R, Georgoulas S, Moessner K, Nati M, Gluhak A, Krco S. (2016) 'An Arrival and Departure Time Predictor for Scheduling Communication in Opportunistic IoT'. MDPI Sensors, 16 (11) Article number 1852

    Abstract

    In this article, an Arrival and Departure Time Predictor (ADTP) for scheduling communication in opportunistic Internet of Things (IoT) is presented. The proposed algorithm learns about temporal patterns of encounters between IoT devices and predicts future arrival and departure times, therefore future contact durations. By relying on such predictions, a neighbour discovery scheduler is proposed, capable of jointly optimizing discovery latency and power consumption in order to maximize communication time when contacts are expected with high probability and, at the same time, saving power when contacts are expected with low probability. A comprehensive performance evaluation with different sets of synthetic and real world traces shows that ADTP performs favourably with respect to previous state of the art. This prediction framework opens opportunities for transmission planners and schedulers optimizing not only neighbour discovery, but the entire communication process.

  • Jin J, Palaniswami M, Yuan D, Dong Y-N, Moessner K. (2016) 'Priority Service Provisioning and Max-Min Fairness: A Utility-based Flow Control Approach'. Springer Journal of Network and Systems Management, , pp. 1-19.
  • Tehrani RH, Vahid S, Triantafyllopoulou D, Lee H, Moessner K. (2016) 'Licensed Spectrum Sharing Schemes for Mobile Operators: A Survey and Outlook'. IEEE Communications Surveys and Tutorials, 18 (4)

    Abstract

    The ongoing development of mobile communication networks to support a wide range of superfast broadband services has led to massive capacity demand. This problem is expected to be a significant concern during the deployment of the 5G wireless networks. The demand for additional spectrum to accommodate mobile services supporting higher data rates and having lower latency requirements, as well as the need to provide ubiquitous connectivity with the advent of the Internet of Things (IoT) sector, is likely to considerably exceed the supply, based on the current policy of exclusive spectrum allocation to mobile cellular systems. Hence, the imminent spectrum shortage has introduced a new impetus to identify practical solutions to make the most efficient use of the scarce licensed bands in a shared manner. Recently, the concept of dynamic spectrum sharing has received considerable attention from regulatory bodies and governments globally, as it could potentially open new opportunities for mobile operators to exploit spectrum bands whenever they are underutilised by their owners, subject to service level agreements. Although various sharing paradigms have been proposed and discussed, the impact and performance gains of different schemes can be scenario-specific and vary depending on the nature of the sharing parties, the level of sharing and spectrum access scheme. In this survey, we describe the main concepts of dynamic spectrum sharing, different sharing scenarios, as well as the major challenges associated with sharing licensed bands. Finally, we conclude this survey paper with open research challenges and suggest some future research directions.

  • Herzog U, Georgakopoulos A, Belikaidis IP, Fitch M, Briggs K, Diaz S, Carrasco O, Moessner K, Miscopein B, Mumtaz S, Demestichas P. (2016) 'Quality of service provision and capacity expansion through extended-DSA for 5G'. Transactions on Emerging Telecommunications Technologies,

    Abstract

    5G systems are expected to advance on a number of aspects compared with current systems, for example, providing a 1000 times higher capacity, a much lower latency and improved quality of user experience. This paper presents the vision and approach followed by the H2020 project SPEED-5G. The approach is based on densification of small cells, exploitation of Multi-RAT, development of new resource management techniques and a more efficient use of spectrum. A novel 5G system architecture is proposed based on the Network Slicing paradigm, which enables a highly flexible, scalable and backwards compatible architecture. A core aspect is the definition of a new MAC layer that facilitates Multi-RAT access and allows prioritising and allocating traffic across heterogeneous access technologies.

  • Zhou Y, De S, Wang W, Moessner K. (2016) 'Search Techniques for the Web of Things: A Taxonomy and Survey'. MDPI AG SENSORS, 16 (5) Article number ARTN 600
  • Palaghias N, Hoseinitabatabaei SA, Nati M, Gluhak A, Moessner K. (2016) 'A Survey on Mobile Social Signal Processing'. ASSOC COMPUTING MACHINERY ACM COMPUTING SURVEYS, 48 (4) Article number ARTN 57
  • Yu X, Navaratnam P, Moessner K, Cruickshank H. (2015) 'Distributed Resource Reservation in Hybrid MAC With Admission Control for Wireless Mesh Networks'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, 64 (12), pp. 5891-5903.
  • Wang W, Yao F, De S, Moessner K, Sun Z. (2015) 'A Ranking Method for Sensor Services based on Estimation of Service Access Cost'. Elsevier Information Sciences, 319, pp. 1-17.
  • Lee H, Ko Y, Vahid S, Moessner K. (2015) 'Practical Spectrum Aggregation for Secondary Networks With Imperfect Sensing'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, 65 (7), pp. 5474-5484.
  • Pozza R, Nati M, Georgoulas S, Moessner K, Gluhak A. (2015) 'Neighbor Discovery for Opportunistic Networking in Internet of Things Scenarios: A Survey'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE ACCESS, 3, pp. 1101-1131.
  • Wang W, De S, Cassar G, Moessner K. (2015) 'An Experimental Study on Geospatial Indexing for Sensor Service Discovery'. Elsevier Expert Systems with Applications, 42 (7), pp. 3528-3538.
  • Alnwaimi G, Vahid S, Moessner K. (2015) 'Dynamic heterogeneous learning games for opportunistic access in LTE-based macro/femtocell deployments'. IEEE Transactions on Wireless Communications, 14 (4), pp. 2294-2308.
  • Chih-Lin I, Uusitalo MA, Moessner K. (2015) 'The 5G Huddle'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE VEHICULAR TECHNOLOGY MAGAZINE, 10 (1), pp. 28-31.
  • Liu X, Evans BG, Moessner K. (2015) 'Energy-efficient sensor scheduling algorithm in cognitive radio networks employing heterogeneous sensors'. IEEE Transactions on Vehicular Technology, 64 (3), pp. 1243-1249.
  • Triantafyllopoulou D, Kollias K, Moessner K. (2015) 'QoS and Energy Efficient Resource Allocation in Uplink SC-FDMA Systems'. IEEE Transactions on Wireless Communications, 14 (6)

    Abstract

    In this paper we present and evaluate the performance of a resource allocation algorithm to enhance the Quality of Service (QoS) provision and energy efficiency of uplink Long Term Evolution (LTE) systems. The proposed algorithm considers the main constraints in uplink LTE resource allocation, i.e., the allocation of contiguous sets of resource blocks of the localized Single Carrier – Frequency Division Multiple Access (SC-FDMA) physical layer to each user, and the imperfect knowledge of the users' uplink buffer status and packet waiting time. The optimal resource allocation is formulated as a discrete connected cake-cutting problem, where different agents are allocated consecutive subsequences of a sequence of indivisible items. This problem is NP-hard, therefore a suboptimal algorithm is introduced, which performs resource allocation using information on the estimated uplink packet delay, the average delay and data rate of past allocations, as well as the required uplink power per resource block. Based on simulation results, the proposed algorithm achieves significant performance improvement in terms of packet timeout rate, goodput, and fairness. Moreover, the effect of poor QoS provision on energy efficiency is demonstrated through the evaluation of the performance in terms of energy consumption per successfully received bit.

  • Nati M, Gluhak A, Domaszewicz J, Lalis S, Moessner K. (2014) 'Lessons from SmartCampus: External Experimenting with User-Centric Internet-of-Things Testbed'. Wireless Personal Communications,
    [ Status: Accepted ]
  • Francois F, Wang N, Moessner K, Georgoulas S, Xu K. (2014) 'On IGP link weight optimization for joint energy efficiency and load balancing improvement'. Computer Communications, 50, pp. 130-141.

    Abstract

    The energy consumption of backbone networks has risen exponentially during the past decade with the advent of various bandwidth-hungry applications. To address this serious issue, network operators are keen to identify new energy-saving techniques to green their networks. Up to this point, the optimization of IGP link weights has only been used for load-balancing operations in IP-based networks. In this paper, we introduce a novel link weight setting algorithm, the Green Load-balancing Algorithm (GLA), which is able to jointly optimize both energy efficiency and load-balancing in backbone networks without any modification to the underlying network protocols. The distinct advantage of GLA is that it can be directly applied on top of existing link-sleeping based Energy-aware Traffic Engineering (ETE) schemes in order to achieve substantially improved energy saving gains, while at the same time maintain traditional traffic engineering objectives. In order to evaluate the performance of GLA without losing generality, we applied the scheme to a number of recently proposed but diverse ETE schemes based on link sleeping operations. Evaluation results based on the European academic network topology GÉANT and its real traffic matrices show that GLA is able to achieve significantly improved energy efficiency compared to the original standalone algorithms, while also achieving near-optimal load-balancing performance. In addition, we further consider end-to-end traffic delay requirements since the optimization of link weights for load-balancing and energy savings may introduce substantially increased traffic delay after link sleeping. In order to solve this issue, we modified the existing ETE schemes to improve their end-to-end traffic delay performance. The evaluation of the modified ETE schemes together with GLA shows that it is still possible to save a significant amount of energy while achieving substantial load-balancing within a given traffic delay constraint. © 2014 Elsevier B.V. All rights reserved.

  • Triantafyllopoulou D, Guo T, Moessner K. (2014) 'Energy-Efficient WLAN Offloading through Network Discovery Period Optimization'. IEEE Transactions on Vehicular Technology, 64 (6)
  • De S, Christophe B, Moessner K. (2014) 'Semantic enablers for dynamic digital-physical object associations in a federated node architecture for the Internet of Things'. Ad Hoc Networks, 18, pp. 102-120.

    Abstract

    The Internet of Things (IoT) paradigm aims to realize heterogeneous physical world objects interacting with each other and with the surrounding environment. In this prospect, the automatic provisioning of the varied possible interactions and bridging them with the digital world is a key pertinent issue for enabling novel IoT applications. The introduction of description logic-based semantics to provide homogeneous descriptions of object capabilities enables lowering the heterogeneity and a limited set of interactions (such as those with stationary objects with fixed availability) to be deduced using classical reasoning systems. However, the inability of such semantics to capture the dynamics of an IoT system as well as the scalability issues that reasoning systems encounter if too many descriptions have to be processed, necessitate that such approaches should be used in conjunction with others. Towards this aim, this paper proposes an automated rule-based association mechanism for integrating the digital IoT components with physical entities along temporal-spatial-thematic axes. To address the scalability issue, this mechanism is distributed over a federated network of nodes, each embodying a set of objects located in the same geographical area. Nodes covering nearby geographical areas can share their object descriptions while all nodes are capable of deducing interactions between the descriptions that they are aware of.© 2013 Elsevier B.V.

  • De S, Christophe B, Moessner K. (2014) 'Semantic Enablers for Dynamic Digital-Physical Object Associations in a Federated Node Architecture for the Internet of Things'. Elsevier Ad Hoc Networks Journal, 18, pp. 102-120.
  • Francois F, Wang N, Moessner K, Georgoulas S, De Oliveira Schmidt R. (2014) 'Leveraging MPLS backup paths for distributed energy-aware traffic engineering'. IEEE Transactions on Network and Service Management, 11 (2), pp. 235-249.

    Abstract

    Backup paths are usually pre-installed by network operators to protect against single link failures in backbone networks that use multi-protocol label switching. This paper introduces a new scheme called Green Backup Paths (GBP) that intelligently exploits these existing backup paths to perform energy-aware traffic engineering without adversely impacting the primary role of these backup paths of preventing traffic loss upon single link failures. This is in sharp contrast to most existing schemes that tackle energy efficiency and link failure protection separately, resulting in substantially high operational costs. GBP works in an online and distributed fashion, where each router periodically monitors its local traffic conditions and cooperatively determines how to reroute traffic so that the highest number of physical links can go to sleep for energy saving. Furthermore, our approach maintains quality-of-service by restricting the use of long backup paths for failure protection only, and therefore, GBP avoids substantially increased packet delays. GBP was evaluated on the point-of-presence representation of two publicly available network topologies, namely, GÉANT and Abilene, and their real traffic matrices. GBP was able to achieve significant energy saving gains, which are always within 15% of the theoretical upper bound. © 2004-2012 IEEE.

  • Poncela J, Vlacheas P, Giaffreda R, De S, Vecchio M, Nechifor S, Barco R, Aguayo-Torres MC, Stavroulaki V, Moessner K, Demestichas P. (2014) 'Smart Cities via Data Aggregation'. Springer Wireless Personal Communications, 76 (2), pp. 149-168.

    Abstract

    Cities have an ever increasing wealth of sensing capabilities, recently including also internet of things (IoT) systems. However, to fully exploit such sensing capabilities with the aim of offering effective city-sensing-driven applications still presents certain obstacles. Indeed, at present, the main limitation in this respect consists of the vast majority of data sources being served on a “best effort” basis. To overcome this limitation, we propose a “resilient and adaptive IoT and social sensing platform”. Resilience guarantees the accurate, timely and dependable delivery of the complete/related data required by smart-city applications, while adaptability is introduced to ensure optimal handling of the changing requirements during application provision. The associated middleware consists of two main sets of functionalities: (a) formulation of sensing requests: selection and discovery of the appropriate data sources; and (b) establishment and control of the necessary resources (e.g., smart objects, networks, computing/storage points) on the delivery path from sensing devices to the requesting applications. The middleware has the intrinsic feature of producing sensing information at a certain level of detail (geographical scope/timeliness/accuracy/completeness/dependability) as requested by the applications in a given domain. The middleware is assessed and validated at a proof-of-concept level through innovative, dependable and real-time applications expected to be highly reproducible across different cities.

  • Jin Y, Vural S, Gluhak A, Moessner K. (2013) 'Dynamic task allocation in multi-hop multimedia wireless sensor networks with low mobility.'. Sensors (Basel, Switzerland), 13 (10), pp. 13998-14028.
  • Lee H, Vahid S, Moessner K. (2013) 'A survey of radio resource management for spectrum aggregation in LTE-advanced'. IEEE Communications Surveys and Tutorials, 16 (2), pp. 745-760.

    Abstract

    In order to satisfy the requirements of future IMT-Advanced mobile systems, the concept of spectrum aggregation is introduced by 3GPP in its new LTE-Advanced (LTE Rel. 10) standards. While spectrum aggregation allows aggregation of carrier components (CCs) dispersed within and across different bands (intra/inter-band) as well as combination of CCs having different bandwidths, spectrum aggregation is expected to provide a powerful boost to the user throughput in LTE-Advanced (LTE-A). However, introduction of spectrum aggregation or carrier aggregation (CA) as referred to in LTE Rel. 10, has required some changes from the baseline LTE Rel. 8 although each CC in LTE-A remains backward compatible with LTE Rel. 8. This article provides a review of spectrum aggregation techniques, followed by requirements on radio resource management (RRM) functionality in support of CA. On-going research on the different RRM aspects and algorithms to support CA in LTE-Advanced are surveyed. Technical challenges for future research on aggregation in LTE-Advanced systems are also outlined. © 2014 IEEE.

  • Wang W, De S, Cassar G, Moessner K. (2013) 'Knowledge Representation in the Internet of Things: Semantic Modelling and its Applications'. KoREMA Automatika – Journal for Control, Measurement, Electronics, Computing and Communications, 54 (4), pp. 388-400.

    Abstract

    Semantic modelling provides a potential basis for interoperating among different systems and applications in the Internet of Things (IoT). However, current work has mostly focused on IoT resource management while not on the access and utilisation of information generated by the “Things”. We present the design of a comprehensive and lightweight semantic description model for knowledge representation in the IoT domain. The design follows the widely recognised best practices in knowledge engineering and ontology modelling. Users are allowed to extend the model by linking to external ontologies, knowledge bases or existing linked data. Scalable access to IoT services and resources is achieved through a distributed, semantic storage design. The usefulness of the model is also illustrated through an IoT service discovery method.

  • Cassar G, Barnaghi P, Moessner K. (2013) 'Probabilistic Matchmaking Methods for Automated Service Discovery'. IEEE Transactions on Service Computing,

    Abstract

    Automated service discovery enables human users or software agents to form queries and to search and discover the services based on different requirements. This enables implementation of high-level functionalities such as service recommendation, composition, and provisioning. The current service search and discovery on the Web is mainly supported by text and keyword based solutions which offer very limited semantic expressiveness to service developers and consumers. This paper presents a method using probabilistic machine-learning techniques to extract latent factors from semantically enriched service descriptions. The latent factors are used to construct a model to represent different types of service descriptions in a vector form. With this transformation, heterogeneous service descriptions can be represented, discovered, and compared on the same homogeneous plane. The proposed solution is scalable to large service datasets and provides an efficient mechanism that enables publishing and adding new services to the registry and representing them using latent factors after deployment of the system. We have evaluated our solution against logic-based and keyword-based service search and discovery solutions. The results show that the proposed method performs better than other solutions in terms of precision and normalised discounted cumulative gain values.

  • Jalili B, Dianati M, Evans BG, Moessner K. (2013) 'Collaborative radio resource allocation for the downlink of multi-cell multi-carrier systems'. IET Communications, 7 (5), pp. 430-438.
  • Zhang R, Wang L, Parr G, Aliu OG, Awoseyila B, Azarmi N, Bhatti S, Bigham J, Bodanese E, Chen H, Dianati M, Dutta A, Fitch M, Giridhar K, Hailes S, Hari KVS, Imran MA, Jagannatham AK, Karandikar A, Kawade S, Khan MZA, Kompalli SC, Langdon P, Narayanan B, Mauthe A, McGeehan J, Mehta N, Millet K, Moessner K, Rajashekar R, Ramkumar B, Ribeiro V, Vasudevan K, Hanzo L. (2013) 'Advances in Base- and Mobile-Station Aided Cooperative Wireless Communications'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE VEHICULAR TECHNOLOGY MAGAZINE, 8 (1), pp. 57-69.
  • Arshad K, Moessner K. (2013) 'Robust Collaborative Spectrum Sensing in the Presence of Deleterious Users'. IET IET Communications, 7 (1), pp. 49-56.

    Abstract

    Collaborative spectrum sensing has attracted significant research attention in the last few years and is widely accepted as a viable approach to improve spectrum sensing reliability. Fusing data from multiple Opportunistic users (OUs) in order to produce reliable sensing results implies a reliance on the OU to provide correct information. In the presence of malfunctioning or selfish users, performance of collaborative spectrum sensing deteriorates significantly. In this article, we propose mechanisms for the detection and suppression of such deleterious opportunistic users (DOUs) for hard and soft decision fusion. More specifically, a credibility based mechanism for hard decision fusion using a beta reputation system (HDC-BR) is introduced. Our proposed method does not require knowledge of the total number of deleterious users in advance. In HDC-BR, the fusion center assigns and updates weights to each user’s decisions based on an individual user credibility score which is calculated using the beta reputation system. The presence of DOUs in soft decision based collaborative spectrum sensing has even more adverse effects on system performance. We also propose a scheme for the case of soft decision fusion to detect and eliminate falsified user observations at the fusion centre using a Modified Grubbs Test; we refer to it as SDC-MG. We compare the performance of the proposed methods with malicious user detection schemes proposed in the literature as well as with the case where no DOU suppression scheme is implemented, and conclude that SDC-MG performs much better than HDC-BR in a low Signal to Noise Ratio (SNR) regime.

  • Jin Y, Vural S, Gluhak A, Moessner K. (2013) 'Dynamic task allocation in multi-hop multimedia wireless sensor networks with low mobility.'. Sensors (Basel), Switzerland: 13 (10), pp. 13998-14028.

    Abstract

    This paper presents a task allocation-oriented framework to enable efficient in-network processing and cost-effective multi-hop resource sharing for dynamic multi-hop multimedia wireless sensor networks with low node mobility, e.g., pedestrian speeds. The proposed system incorporates a fast task reallocation algorithm to quickly recover from possible network service disruptions, such as node or link failures. An evolutional self-learning mechanism based on a genetic algorithm continuously adapts the system parameters in order to meet the desired application delay requirements, while also achieving a sufficiently long network lifetime. Since the algorithm runtime incurs considerable time delay while updating task assignments, we introduce an adaptive window size to limit the delay periods and ensure an up-to-date solution based on node mobility patterns and device processing capabilities. To the best of our knowledge, this is the first study that yields multi-objective task allocation in a mobile multi-hop wireless environment under dynamic conditions. Simulations are performed in various settings, and the results show considerable performance improvement in extending network lifetime compared to heuristic mechanisms. Furthermore, the proposed framework provides noticeable reduction in the frequency of missing application deadlines.

  • Liu X, Evans BG, Moessner K. (2013) 'Comparison of reliability, delay and complexity for standalone cognitive radio spectrum sensing schemes'. IET Communications, 7 (9), pp. 799-807.
  • Yu X, Navaratnam P, Moessner K. (2013) 'Resource reservation schemes for IEEE 802.11-based wireless networks: A survey'. IEEE Communications Surveys and Tutorials, 15 (3), pp. 1042-1061.
  • Arshad K, Moessner K. (2013) 'Robust spectrum sensing based on statistical tests'. IET Communications, 7 (9), pp. 808-817.

    Abstract

    Spectrum sensing, in particular, detecting the presence of licensed or incumbent users in licensed spectrum, is one of the pivotal tasks in cognitive radio network. In this study, the authors tackle the spectrum sensing problem by using statistical test theory and derive novel spectrum sensing approaches. The authors apply the classical Kolmogorov-Smirnov (KS) test under the assumption that the noise probability distribution is known. However, as in practice, the exact noise distribution is unknown, a sensing method for Gaussian noise with unknown noise power is proposed in this article and referred to t-sensing. The proposed sensing scheme is asymptotically robust and can be applied to non-Gaussian noise distributions. A closed form equation determining the miss-detection probability for the t-sensing is derived. The authors compare with the performance of our sensing algorithms with the energy detector and Anderson-Darling (AD) sensing methods proposed in literature. Simulation results show that the proposed sensing methods outperform both ED- and AD-based sensing, especially for the case when the received signal-to-noise ratio is low. © The Institution of Engineering and Technology 2013.

  • Vlacheas P, Giaffreda R, Stavroulaki V, Kelaidonis D, Foteinos V, Poulios G, Demestichas P, Somov A, Biswas A, Moessner K. (2013) 'Enabling smart cities through a cognitive management framework for the internet of things'. IEEE Communications Magazine, 51 (6), pp. 102-111.
  • Foteinos V, Kelaidonis D, Poulios G, Stavroulaki V, Vlacheas P, Demestichas P, Giaffreda R, Biswas AR, Menoret S, Nguengang G, Etelapera M, Septimiu-Cosmin N, Roelands M, Visintainer F, Moessner K. (2013) 'A cognitive management framework for empowering the internet of things'. Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 7858 LNCS, pp. 187-199.

    Abstract

    This work presents a Cognitive Management framework for empowering the Internet of Things (IoT). This framework has the ability to dynamically adapt its behaviour, through self-management functionality, taking into account information and knowledge (obtained through machine learning) on the situation (e.g., internal status and status of environment), as well as policies (designating objectives, constraints, rules, etc.). Cognitive technologies constitute a unique and efficient approach for addressing the technological heterogeneity of the IoT and obtaining situation awareness, reliability and efficiency. The paper also presents a first indicative implementation of the proposed framework, comprising real sensors and actuators. The preliminary results of this work demonstrate high potential towards self-reconfigurable IoT. © The Author(s).

  • Ko Y, Moessner K. (2012) 'Maximum outage capacity in dense indoor femtocell networks with joint energy and spectrum utilization'. IEEE Transactions on Wireless Communications, 11 (12), pp. 4416-4425.

    Abstract

    We consider a multiple femtocell deployment in a small area which shares spectrum with the underlaid macrocell. We design a joint energy and radio spectrum scheme which aims not only for co-existence with the macrocell, but also for an energy-efficient implementation of the multi-femtocells. Particularly, aggregate energy usage on dense femtocell channels is formulated taking into account the cost of both the spectrum and energy usage. We investigate an energy-and-spectral efficient approach to balance between the two costs by varying the number of active sub-channels and their energy. The proposed scheme is addressed by deriving closed-form expressions for the interference towards the macrocell and the outage capacity. Analytically, discrete regions under which the most promising outage capacity is achieved by the same size of active sub-channels are introduced. Through a joint optimization of the sub-channels and their energy, properties can be found for the maximum outage capacity under realistic constraints. Using asymptotic and numerical analysis, it can be noticed that in a dense femtocell deployment, the optimum utilization of the energy and the spectrum to maximize the outage capacity converges towards a round-robin scheduling approach for a very small outage threshold. This is the inverse of the traditional greedy approach. © 2012 IEEE.

  • Francois F, Wang N, Moessner K, Georgoulas S. (2012) 'Optimizing Link Sleeping Reconfigurations in ISP Networks with Off-Peak Time Failure Protection'. IEEE IEEE Transactions on Network and Service Management, 10 (2), pp. 176-188.
  • Yu X, Navaratnam P, Moessner K. (2012) 'Resource reservation schemes for IEEE 802.11e based wireless networks'. IEEE Communications Surveys and Tutorials,
  • AlShahwan F, Carrez F, Moessner K. (2012) 'Providing and evaluating the mobile Web service distribution mechanisms using fuzzy logic'. Academy Publisher Journal of Software, 7 (7), pp. 1473-1487.

    Abstract

    providing adaptive resource intensive Web services from mobile hosts needs to be done in a rather light-weight manner to allow continuous service provisioning. Processing and communication will drain the battery rapidly; hence both should be kept at a minimum. This paper describes the outcomes of an investigation into offloading and migration mechanisms that facilitate provision of adaptive and distributed mobile Web services. The investigation goes through three phases. The first phase integrates these mechanisms with the Simple Object Access Protocol (SOAP) and Representational State Transfer (REST) architectures producing extended mobile Web service frameworks. This phase is achieved by the implementation of a prototype that allows performance evaluation of both extended frameworks. The evaluation of the load and performance of the distributed services is taking place using resource intensive applications. The results presented show that basing distributed mobilehosted services on REST is more suitable than using SOAP as underlying Web service infrastructure. The second phase relies on the outperforming REST-based framework to examine four distinct strategies for mobile Web service distribution mechanisms. In the last phase, evaluation results of the second phase are interpreted as Fuzzy Logic rules. These rule sets are used to trigger and control offloading schemes. © 2012 ACADEMY PUBLISHER.

  • Yu X, Navaratnam P, Moessner K. (2012) 'Distributed Admission Control with Soft Resource Allocation for Hybrid MAC in P2P Wireless Networks'. Computer Networks,
    [ Status: Submitted ]
  • Xiao P, Tafazolli R, Moessner K, Gluhak A. (2012) 'Codebook Based Single-User MIMO System Design with Widely Linear Processing'. IEEE Transactions on Communications,

    Abstract

    This work addresses joint transceiver optimization for multiple-input, multiple-output (MIMO) systems. In practical systems the complete knowledge of channel state information (CSI) is hardly available at transmitter. To tackle this problem, we resort to the codebook approach to precoding design, where the receiver selects a precoding matrix from a finite set of pre-defined precoding matrices based on the instantaneous channel condition and delivers the index of the chosen precoding matrix to the transmitter via a bandwidth-constraint feedback channel. We show that, when the symbol constellation is improper, the joint codebook based precoding and equalization can be designed accordingly to achieve improved performance compared to the conventional system.

  • Yu X, Navaratnam P, Moessner K. (2012) 'Performance analysis of distributed resource reservation in IEEE 802.11e-based wireless networks'. IET Communications, 6 (11), pp. 1447-1455.

    Abstract

    Guaranteeing quality of service (QoS) is one of the most critical challenges in IEEE 802.11-based wireless networks. This study proposes an analytical framework to evaluate hybrid medium access control (MAC) scheduling mechanisms with distributed resource reservation (RR), that was proposed for the IEEE 802.11e-enhanced distributed channel access protocol for guaranteeing QoS. The hybrid MAC scheduling mechanisms split the airtime into service intervals with contention-free period for QoS guaranteed real-time sessions (RTSNs), and contention access period for other traffic sessions. The distributed RR ensures that the resources are allocated to RTSNs without the support of a centralised controller-this makes it suitable for ad hoc networking applications. The proposed analytical framework models the QoS (i.e. delay and throughput) performance of RTSNs with dedicated resources in a distributed environment, and also estimates the overall capacity of the network. Moreover, the derived models can be used to investigate the impact of changes to individual system parameters, such as service interval or size of transmission opportunity. The simulation results show that the proposed analytical framework precisely models the QoS performance of RTSNs and predicts the optimum resource allocation for improved network capacity. © 2012 The Institution of Engineering and Technology.

  • Bantouna, A , Stavroulaki V, Kritikou Y, Tsagkaris K, Demestichas P, Moessner K. (2012) 'An overview of learning mechanisms for cognitive systems'. Springer EURASIP Journal on Wireless Communications and Networking 2012, 2012 (22)

    Abstract

    Cognitive systems were first introduced by Mitola and in the last decade they have proved to be beneficial in self-management functionalities of future generation networks. The advantages and the way that networks gain benefits from cognitive systems is analysed in this article. Moreover, since such systems are closely related to machine learning, the focus of this article is also placed on machine learning techniques applied both in the network and the user devices side. In particular, celebrating 10 years of cognitive systems, this survey-oriented article presents an extended state-of-the-art of machine learning applied to cognitive systems as coming from the recent research and an overview of three different learning capabilities of both the network and the user device.

  • Vural S, Wei D, Moessner K. (2012) 'Survey of Experimental Evaluation Studies for Wireless Mesh Network Deployments in Urban Areas Towards Ubiquitous Internet'. IEEE IEEE Communications Surveys and Tutorials, PP (99), pp. 1-17.

    Abstract

    Establishing wireless networks in urban areas that can provide ubiquitous Internet access to end-users is a central part of the efforts towards defining the Internet of the future. In recent years, Wireless Mesh Network (WMN) backbone infrastructures are proposed as a cost effective technology to provide city-wide Internet access. Studies that evaluate the performance of city-wide mesh network deployments via experiments provide essential information on various challenges of building them. In this survey, we particularly focus on such studies and provide brief conclusions on the problems, benefits, and future research directions of city-wide WMNs.

  • Zahir T, Arshad K, Nakata A, Moessner K. (2012) 'Interference Management in Femtocells'. IEEE IEEE Communications Surveys and Tutorials, 15 (1), pp. 293-311.

    Abstract

    Increase in system capacity and data rates can be achieved efficiently in a wireless system by getting the transmitter and receiver closer to each other. Femtocells deployed in the macrocell significantly improve the indoor coverage and provide better user experience. The femtocell base station called as Femtocell Access Point (FAP) is fully user deployed and hence reduces the infrastructure, maintenance and operational cost of the operator while at the same time providing good Quality of Service (QoS) to the end user and high network capacity gains. However, the mass deployment of femtocell faces a number of challenges, among which interference management is of much importance, as the fundamental limits of capacity and achievable data rates mainly depends on the interference faced by the femtocell network. To cope with the technical challenges including interference management faced by the femtocells, researchers have suggested a variety of solutions. These solutions vary depending on the physical layer technology and the specific scenarios considered. Furthermore, the cognitive capabilities, as a functionality of femtocell have also been discussed in this survey. This article summarises the main concepts of femtocells that are covered in literature and the major challenges faced in its large scale deployment. The main challenge of interference management is discussed in detail with its types in femtocells and the solutions proposed over the years to manage interference have been summarised. In addition an overview of the current femtocell standardisation and the future research direction of femtocells have also been provided.

  • Stavroulaki V, Bantouna A, Kritikou Y, Tsagkaris K, Demestichas P, Blasco P, Bader F, Dohler M, Denkovski D, Atanasovski V, Gavrilovska L, Moessner K. (2012) 'Knowledge management toolbox: Machine learning for cognitive radio networks'. IEEE Vehicular Technology Magazine, 7 (2), pp. 91-99.

    Abstract

    Learning mechanisms are essential for the attainment of experience and knowledge in cognitive radio (CR) systems, exposed to high dynamics with often unpredictable states [1]. These mechanisms can be associated with user and device profiles, context, and decisions. The focus learning user preferences is the dynamic inference and estimation of current and future user preferences. The acquisition and learning of context information encompasses mechanisms for the system to perceive its current status and conditions in its present environment, as well as estimating (and forecasting) the capabilities of available network configurations. Finally, learning related to decisions addresses the building of knowledge with respect to the efficiency of solutions that can be applied to specific situations encountered. Based on knowledge obtained through learning, decision-making mechanisms can become faster, since the CR system can learn and immediately apply solutions that have been identified as being efficient in the past. Moreover, knowledge obtained through learning mechanisms may be shared among nodes of a system. Thus, more reliable and more optimal decisions can be made by exploiting knowledge obtained through learning mechanisms. © 2005-2012 IEEE.

  • Rostami S, Arshad K, Moessner K. (2012) 'Order-statistic based spectrum sensing for cognitive radio'. IEEE Communications Letters, 16 (5), pp. 592-595.

    Abstract

    Spectrum sensing for cognitive radio is challenging. In this letter, a spectrum sensing method based on quintiles of Order-Statistics is proposed. We derive the test statistic and evaluate the performance of the proposed method by Monte Carlo simulations. Simulation results show that order statistics based sensing considerably outperforms both energy detection and anderson darling based sensing in an Additive White Gaussian Noise (AWGN) channel; especially in a lower signal to noise ratio region. © 2012 IEEE.

  • Baldini G, Prasad RRV, Biswas AR, Moessner K, Etelapera M, Soininen J-P, Nechifor D-C, Stavroulaki V, Vlacheas P. (2012) 'A cognitive management framework to support exploitation of the future internet of things'. Scalable Computing, 13 (2), pp. 139-147.

    Abstract

    In this article, a cognitive management framework is proposed for ensuring exploitation of the Future Internet of Things (FIoT). Cognitive systems offer self-x and learning. A cognitive system has the ability to dynamically select its behavior through self-management/awareness functionality, taking into account information and knowledge on the context of the operations as well as policies and including the generation of the context itself. The framework is based on the principle that any real world object and any digital object that is available, accessible, observable or controllable can have a virtual representation in the Future Internet, which is called Virtual Object (VO). Basic VOs can be composed in a more sophisticated way by forming Composite VOs (CVOs), which provide services to high-level applications and end-users. The described paradigm is applied to various applications scenarios: smart home, smart office, smart city and smart business. This paper presents some background in IoT, identifies the requirements and challenges, and sets the directions that should be followed. © 2012 SCPE.

  • Georgoulas S, Moessner K, Mansour A, Pissarides M, Spapis P. (2012) 'A fuzzy reinforcement learning approach for pre-congestion notification based admission control'. Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 7279 LNCS, pp. 26-37.

    Abstract

    Admission control aims to compensate for the inability of slow-changing network configurations to react rapidly enough to load fluctuations. Even though many admission control approaches exist, most of them suffer from the fact that they are based on some very rigid assumptions about the per-flow and aggregate underlying traffic models, requiring manual reconfiguration of their parameters in a "trial and error" fashion when these original assumptions stop being valid. In this paper we present a fuzzy reinforcement learning admission control approach based on the increasingly popular Pre-Congestion Notification framework that requires no a priori knowledge about traffic flow characteristics, traffic models and flow dynamics. By means of simulations we show that the scheme can perform well under a variety of traffic and load conditions and adapt its behavior accordingly without requiring any overly complicated operations and with no need for manual and frequent reconfigurations. © 2012 IFIP International Federation for Information Processing.

  • Tandur D, Duplicy J, Arshad K, Depierre D, Moessner K, Lehtomaki J, Briggs K, Goncalves L, Gameiro A. (2012) 'COGNITIVE RADIO SYSTEMS EVALUATION Measurement, Modeling, and Emulation Approach'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE VEHICULAR TECHNOLOGY MAGAZINE, 7 (2), pp. 77-84.
  • Murroni M, Venkatesha Prasad R, Marques P, Bochow B, Noguet D, Sun C, Harada H, Moessner K. (2011) 'IEEE 1900.6: Spectrum Sensing Interfaces and Data Structures for Dynamic Spectrum Access and Other Advanced Radio Communication Systems Standard: Technical Aspects and Future Outlook'. IEEE IEEE Communications Magazine, 49 (12), pp. 118-127.
  • Wei D, Jin Y, Vural S, Moessner K, Tafazolli R. (2011) 'An Energy-efficient Clustering Solution for Wireless Sensor Networks'. IEEE Transactions on Wireless Communications, United Kingdom: PP (99), pp. 1-11.

    Abstract

    Hot spots in a wireless sensor network emerge as locations under heavy traffic load. Nodes in such areas quickly deplete energy resources, leading to disruption in network services. This problem is common for data collection scenarios in which Cluster Heads (CH) have a heavy burden of gathering and relaying information. The relay load on CHs especially intensifies as the distance to the sink decreases. To balance the traffic load and the energy consumption in the network, the CH role should be rotated among all nodes and the cluster sizes should be carefully determined at different parts of the network. This paper proposes a distributed clustering algorithm, Energy-efficient Clustering (EC), that determines suitable cluster sizes depending on the hop distance to the data sink, while achieving approximate equalization of node lifetimes and reduced energy consumption levels. We additionally propose a simple energy-efficient multihop data collection protocol to evaluate the effectiveness of EC and calculate the end-to-end energy consumption of this protocol; yet EC is suitable for any data collection protocol that focuses on energy conservation. Performance results demonstrate that EC extends network lifetime and achieves energy equalization more effectively than two well-known clustering algorithms, HEED and UCR.

  • Alnwaimi G, Arshad K, Moessner K. (2011) 'Dynamic spectrum allocation algorithm with interference management in co-existing networks'. IEEE Communications Letters, 15 (9), pp. 932-934.
  • Moessner K, Georgoulas S. (2011) 'Towards Efficient Protocol Design through Protocol Profiling and Performance Assessment: Using Formal Verification in a Different Context'. Wiley International Journal of Communication Systems, 25 (11)

    Abstract

    The most common use of formal verification methods so far has been in identifying whether livelock and/or deadlock situations can occur during protocol execution, process, or system operation. In this work, we aim to show that an additional equally important and useful application of formal verification methods can be in protocol design in terms of performance-related metrics. This can be achieved by using the methods in a rather different context compared with their traditional use, that is, not only as model checking tools to assess the correctness of a protocol in terms of lack of livelock and deadlock situations but rather as tools capable of building profiles of protocol operations, assessing their performance, and identifying operational patterns and possible bottleneck operations. This process can provide protocol designers with an insight about the protocols' behavior and guide them toward further optimizations. It can also assist network operators and service providers to assess the protocols' relative performance and select the most suitable protocol for specific deployment scenarios. We illustrate these principles by showing how formal verification tools can be applied in this protocol profiling and performance assessment context using some existing protocol implementations in mobile and wireless environments as case studies. Copyright © 2011 John Wiley & Sons, Ltd.

  • Jin Y, Jin J, Gluhak A, Moessner K, Palaniswami M. (2011) 'An Intelligent Task Allocation Scheme for Multi-hop Wireless Networks'. IEEE Computer Society IEEE Transactions on Parallel and Distributed Systems, 23 (3), pp. 444-451.
  • Durowoju O, Arshad K, Moessner K. (2011) 'Distributed power control algorithm for cognitive radios with primary protection via spectrum sensing under user mobility'. Elsevier Ad Hoc Networks, 10 (5), pp. 740-751.
  • Moessner K, Harada H, Sun C, Alemseged Y, Tran H, Noguet D, Sawai R, Sato N. (2011) 'Spectrum sensing for cognitive radio systems: Technical aspects and standardization activities of the IEEE P1900.6 working group'. IEEE Wireless Communications, 18 (1), pp. 30-37.
  • AlShahwan F, Moessner K, Carrez F. (2010) 'Evaluation of Distributed SOAP and RESTful MobileWeb Services'. IARIA International Journal on Advances in Networks and Services, 3 (3 & 4), pp. 447-461.

    Abstract

    Even mobile Web Services are still provided using servers that usually reside in the core networks. Main reason for not providing large and complex Web Services from resource limited mobile devices is not only the volatility of wireless connections and mobility of mobile hosts, but also, the often limited processing power. Offloading of some of the processing tasks is one step towards achieving optimal mobile Web Service provision. This paper presents two frameworks for providing distributed mobile Web Services: One mobile service provision framework is built on Simple Object Access Protocol (SOAP), while the other implements Representational State Transfer (REST) architecture. Both frameworks have been extended with offloading functionality and different types of resource intensive operations, i.e., process intensive and bandwidth intensive services, have been tested. The results show that using a REST-based framework leads of a better performing offloading behaviour, compared to SOAP-based mobile services. Distributed mobile services based on REST consume fewer resources and achieve better performance compared to SOAP based mobile services. The paper describes the approach, evaluation method and findings.

  • Kernchen R, Meissner S, Moessner K, Cesar P, Vaishnavi I, Boussard M, Hesselman C. (2010) 'Intelligent Multimedia Presentation in Ubiquitous Multidevice Scenarios'. IEEE COMPUTER SOC IEEE MULTIMEDIA, 17 (2), pp. 52-62.
  • Chantaraskul S, Moessner K. (2010) 'Implementation of a genetic algorithm-based decision making framework for opportunistic radio'. INST ENGINEERING TECHNOLOGY-IET IET COMMUNICATIONS, 4 (5), pp. 495-506.
  • Arshad K, Imran MA, Moessener K. (2010) 'Collaborative Spectrum Sensing Optimisation Algorithms for Cognitive Radio Networks'. Hindawi Publishing Corporation International Journal of Digital Multimedia Broadcasting, 2010 Article number Article ID 424036

    Abstract

    The main challenge for a cognitive radio is to detect the existence of primary users reliably in order to minimise the interference to licensed communications. Hence, spectrum sensing is a most important requirement of a cognitive radio. However, due to the channel uncertainties, local observations are not reliable and collaboration among users is required. Selection of fusion rule at a common receiver has a direct impact on the overall spectrum sensing performance. In this paper, optimisation of collaborative spectrum sensing in terms of optimum decision fusion is studied for hard and soft decision combining. It is concluded that for optimum fusion, the fusion centre must incorporate signal-to-noise ratio values of cognitive users and the channel conditions. A genetic algorithm-based weighted optimisation strategy is presented for the case of soft decision combining. Numerical results show that the proposed optimised collaborative spectrum sensing schemes give better spectrum sensing performance.

  • Demestichas P, Moessner K, Smirnov M, Bourse D. (2010) 'Functionality and Collaboration Mechanisms for Cognitive Wireless Networks and Systems'. SPRINGER JOURNAL OF NETWORK AND SYSTEMS MANAGEMENT, 18 (1), pp. 1-3.
  • Li N, Tarus H, Irvine JM, Moessner K. (2010) 'A communication middleware for ubiquitous multimedia adaptation services'. Computing and Informatics, 29 (4), pp. 629-646.
  • Thilakawardana D, Moessner K. (2009) 'Traffic modelling and forecasting using genetic algorithms for next-generation cognitive radio applications'. SPRINGER FRANCE ANNALES DES TELECOMMUNICATIONS-ANNALS OF TELECOMMUNICATIONS, 64 (7-8), pp. 535-543.
  • Dimitrakopoulos G, Demestichas P, Tsagkaris K, Saatsakis A, Moessner K, Muck M, Bourse D. (2009) 'Emerging, Self-Management Functionality for Introducing Cognition in the Wireless, B3G World'. SPRINGER WIRELESS PERSONAL COMMUNICATIONS, 48 (1), pp. 33-47.
  • Prammanee S, Moessner K. (2008) 'Mobile Multimodality: A Theoretical Approach to Facilitate Virtual Device Environments'. SPRINGER MOBILE NETWORKS & APPLICATIONS, 13 (6), pp. 569-582.
  • Thilakawardana D, Moessner K, Tafazolli R. (2008) 'Darwinian approach for dynamic spectrum allocation in next generation systems'. INST ENGINEERING TECHNOLOGY-IET IET COMMUNICATIONS, 2 (6), pp. 827-836.
  • Akhtar N, Moessner K. (2008) 'On the nominal capacity of multi-radio multi-channel wireless mesh networks'. ELSEVIER SCIENCE BV COMPUTER COMMUNICATIONS, 31 (8), pp. 1475-1483.
  • El Saddik A, Moessner K, Selçuk Candan K, Liang B, Liu J. (2008) 'ACM/springer mobile networks and applications (MONET): Special issue on "ambient media and systems"'. Mobile Networks and Applications, 13 (6), pp. 543-546.
  • Georgiades M, Moessner K, Dagiuklas T. (2008) 'On the enhancement of mobility and multimedia communications in heterogeneous RANs'. International Journal of Internet Protocol Technology, 3 (1), pp. 22-34.
  • Gluhak A, Inoue M, Moessner K, Tafazolli R. (2007) 'Signaling channel for coordinated multicast service delivery in next generation wireless networks'. IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG IEICE TRANSACTIONS ON COMMUNICATIONS, E90B (7), pp. 1780-1790.
  • Huang L, Chew KA, Thilakawardana S, Liu Y, Moessner K, Tafazolli R. (2006) 'Efficient group-based multimedia-on-demand service delivery in wireless networks'. IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC IEEE TRANSACTIONS ON BROADCASTING, 52 (4), pp. 492-504.
  • Rodriguez V, Moessner K, Tafazolli R. (2006) 'Market driven dynamic spectrum allocation over space and time among radio-access networks: DVB-T and B3G CDMA with heterogeneous terminals'. SPRINGER MOBILE NETWORKS & APPLICATIONS, 11 (6), pp. 847-860.
  • Dimitrakopoulos G, Moessner K, Kloeck C, Grandblaise D, Gault S, Sallent O, Tsagkaris K, Demestichas P. (2006) 'Adaptive resource management platform for reconfigurable networks'. SPRINGER MOBILE NETWORKS & APPLICATIONS, 11 (6), pp. 799-811.
  • Prammanee S, Moessner K, Tafazolli R. (2006) 'Discovering modalities for adaptive multimodal interfaces'. ACM Interactions, 13 (3), pp. 66-70.
  • Leaves P, Moessner K, Tafazolli R, Grandblaise D, Bourse D, Tonjes R, Breveglieri M. (2004) 'Dynamic spectrum allocation in composite reconfigurable wireless networks'. IEEE_M_COM, 42 Article number 5 , pp. 72-81.

Conference papers

  • Bouali F, Moessner K, Fitch M. (2017) 'A Context-aware User-driven Strategy to Exploit Offloading and Sharing in Ultra-dense Deployments'. IEEE 2017 IEEE ICC Conference Proceedings, Paris, France: IEEE ICC 2017 Mobile and Wireless Networking
    [ Status: Accepted ]
  • Zhou Y, De S, Moessner K. (2016) 'Real world city event extraction from Twitter data streams'. Procedia Computer Science, London, UK: International Workshop on Data Mining on IoT Systems (DaMIS16) 98, pp. 443-448.

    Abstract

    The immediacy of social media messages means that it can act as a rich and timely source of real world event information. The detected events can provide a context to observations made by other city information sources such as fixed sensor installations and contribute to building ‘city intelligence’. In this work, we propose a novel unsupervised method to extract real world events that may impact city services such as traffic, public transport, public safety etc., from Twitter streams. We also develop a named entity recognition model to obtain the precise location of the related events and provide a qualitative estimation of the impact of the detected events. We apply our developed approach to a real world dataset of tweets collected from the city of London.

  • Bouali F, Moessner K, Fitch M. (2016) 'A Context-Aware User-Driven Framework for Network Selection in 5G Multi-RAT environments'. Montréal: 2016 IEEE 84th Vehicular Technology Conference
    [ Status: Accepted ]

    Abstract

    To improve inter-operability of future 5G systems with existing technologies, this paper proposes a novel context-aware user-driven framework for network selection in multi- RAT environments. It relies on fuzzy logic to cope with the lack of information usually associated with the terminal side and the intrinsic randomness of the radio environment. In particular, a fuzzy logic controller first estimates the out-of-context suitability of each RAT to support the QoS requirements of a set of heterogeneous applications. Then, a fuzzy multiple attribute decision making (MADM) methodology is developed to combine these estimates with the various components of the context (e.g., terminal capabilities, user preferences and operator policies) to derive the in-context suitability level of each RAT. Based on this novel metric, two spectrum selection and spectrum mobility functionalities are developed to select the best RAT in a given context. The proposed fuzzy MADM approach is validated in a dense small cell environment to perform a context-aware offloading for a mixture of delay-sensitive and best-effort applications. The results reveal that the fuzzy logic component is able to efficiently track changes in the operating conditions of the different RATs, while the MADM component enables to implement an adjustable context-aware strategy. The proposed fuzzy MADM approach results in a significant improvement in achieving the target strategy, while maintaining an acceptable QoS level compared to a traditional offloading based on signal strength.

  • Akbar A, Carrez F, Moessner K, Zoha A. (2015) 'Predicting Complex Events for Pro-Active IoT Applications'. IEEE 2015 IEEE 2ND WORLD FORUM ON INTERNET OF THINGS (WF-IOT), Milan, ITALY: 2015 IEEE 2nd World Forum on Internet of Things (WF-IoT), pp. 327-332.
  • Akbar A, Carrez F, Moessner K, Sancho J, Rico J. (2015) 'Context-Aware Stream Processing for Distributed IoT Applications'. IEEE 2015 IEEE 2ND WORLD FORUM ON INTERNET OF THINGS (WF-IOT), Milan, ITALY: 2015 IEEE 2nd World Forum on Internet of Things (WF-IoT), pp. 663-668.
  • Triantafyllopoulou D, Moessner K. (2015) 'QoS and Energy Efficient Resource Allocation in Downlink OFDMA systems'. London, United Kingdom: IEEE International Conference on Communications (ICC) 2015
    [ Status: Accepted ]

    Abstract

    In this paper we present and evaluate the performance of a resource allocation algorithm to enhance the Quality of Service (QoS) provision and energy efficiency of downlink Orthogonal Frequency Division Multiple Access (OFDMA) systems. The proposed algorithm performs resource allocation using information on the downlink packet delay, the average delay and data rate of past allocations, as well as the downlink users' buffer status in order to minimize packet segmentation. Based on simulation results, the proposed algorithm achieves significant performance improvement in terms of packet timeout rate, goodput, fairness, and average delay. Moreover, the effect of poor QoS provision on energy efficiency is demonstrated through the evaluation of the performance in terms of energy consumption per successfully received bit.

  • Rai MR, Vahid S, Moessner K. (2015) 'SINR based Topology Control for Multihop Wireless Networks with Fault Tolerance'. IEEE 2015 IEEE 81ST VEHICULAR TECHNOLOGY CONFERENCE (VTC SPRING), Univ Strathclyde, Technol Innovat Ctr, Glasgow, SCOTLAND: 81st IEEE Vehicular Technology Conference (VTC Spring)
  • Ibrahim A, Carrez F, Moessner K. (2015) 'Geospatial Ontology-based Mission Assignment in Wireless Sensor Networks'. IEEE 2015 INTERNATIONAL CONFERENCE ON RECENT ADVANCES IN INTERNET OF THINGS (RIOT), Singapore, SINGAPORE: 2015 International Conference on Recent Advances in Internet of Things (RIoT)
  • Akbar A, Nati M, Carrez F, Moessner K. (2015) 'Contextual Occupancy Detection for Smart Office by Pattern Recognition of Electricity Consumption Data'. IEEE 2015 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS (ICC), London, ENGLAND: IEEE International Conference on Communications (ICC), pp. 561-566.
  • Palaghias N, Hoseinitabatabaei SA, Nati M, Gluhak A, Moessner K. (2015) 'Accurate Detection of Real-world Social Interactions with Smartphones'. IEEE 2015 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS (ICC), London, ENGLAND: IEEE International Conference on Communications (ICC), pp. 579-585.
  • Alnwaimi G, Vahid S, Moessner K. (2015) 'Distributed Learning Game based Spectrum Sharing and Resource Selection for Femtocells'. IEEE 2015 22ND INTERNATIONAL CONFERENCE ON TELECOMMUNICATIONS (ICT), Sydney, AUSTRALIA: 22nd International Conference on Telecommunications (ICT), pp. 331-337.
  • Zhou Y, De S, Wang W, Moessner K. (2014) 'Enabling Query of Frequently Updated Data from Mobile Sensing Sources'. IEEE Chengdu, China: 13th IEEE International Conference on Ubiquitous Computing and Communications (IUCC 2014)
  • Pozza R, Nati M, Georgoulas S, Gluhak A, Moessner K, Krco S. (2014) 'CARD: Context-Aware Resource Discovery for mobile Internet of Things scenarios'. Sydney, Australia: IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM 2014)
  • Poncela J, Vlacheas P, Giaffreda R, De S, Vecchio M, Nechifor S, Barco R, Aguayo-Torres MC, Stavroulaki V, Moessner K, Demestichas P. (2014) 'Smart cities via data aggregation'. Wireless Personal Communications, 76 (2), pp. 149-168.
  • Reetz ES, Kuemper D, Moessner K, Tönjes R. (2014) 'Investigation of opportunities for test case selection optimisation based on similarity computation and search-based minimisation algorithms'. VALID 2014 - 6th International Conference on Advances in System Testing and Validation Lifecycle, , pp. 14-20.
  • Lee H, Vahid S, Moessner K. (2014) 'A sub-optimal channel switching-aware spectrum aggregation approach for CRNs'. Proceedings of the 2014 9th International Conference on Cognitive Radio Oriented Wireless Networks and Communications, CROWNCOM 2014, , pp. 114-119.
  • Lee H, Ko Y, Vahid S, Moessner K. (2014) 'Opportunistic spectrum aggregation for cognitive communications under collision constraints'. Proceedings of the 2014 9th International Conference on Cognitive Radio Oriented Wireless Networks and Communications, CROWNCOM 2014, , pp. 7-12.
  • Lee H, Vahid S, Moessner K. (2014) 'The study on spectrum/channel fragmentation from dynamic spectrum aggregation in CRNs'. EuCNC 2014 - European Conference on Networks and Communications,
  • Zhou Y, De S, Moessner K. (2013) 'Implementation of Federated Query Processing on Linked Data'. IEEE London, UK: 24th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), pp. 3553-3557.
  • Triantafyllopoulou D, Guo T, Moessner K. (2013) 'Optimal Network Discovery Period for Energy-Efficient WLAN Offloading'. Las Vegas, NV, USA: IEEE 78th Vehicular Technology Conference (VTC2013-Fall) 2013

    Abstract

    In this paper we present an analytical framework that aims to improve the energy efficiency of traffic offloading via Wireless Local Area Networks, taking into account the energy consumption for both data transmission and network discovery operations. More specifically, the network scanning period is optimized in order to minimize the energy consumption in a vehicular scenario where a user moves along a road covered by a long range cellular network and a number of randomly deployed Wireless Local Area Networks. The performance of the system that performs periodic network scanning with the optimal period is compared against a sub-optimal system that does not take into consideration the user and network context information when determining the network scanning period. According to performance evaluation results, the use of the optimal network scanning period achieves significant improvement in terms of energy consumption and network detection delay.

  • Cassar G, Barnaghi P, Wang W, De S, Moessner K. (2013) 'Composition of Services in Pervasive Environments: A Divide and Conquer Approach'. Split Croatia: the 18th IEEE Symposium on Computers and Communications
  • Cassar G, Barnaghi P, Wang W, De S, Moessner K. (2013) 'Composition of Services in Pervasive Environments: A Divide and Conquer Approach'. IEEE Split, Croatia: 18th IEEE Symposium on Computers and Communications

    Abstract

    In pervasive environments, availability and reliability of a service cannot always be guaranteed. In such environments, automatic and dynamic mechanisms are required to compose services or compensate for a service that becomes unavailable during the runtime. Most of the existing works on services composition do not provide sufficient support for automatic service provisioning in pervasive environments. We propose a Divide and Conquer algorithm that can be used at the service runtime to repeatedly divide a service composition request into several simpler sub-requests. The algorithm repeats until for each sub-request we find at least one atomic service that meets the requirements of that sub-request. The identified atomic services can then be used to create a composite service. We discuss the technical details of our approach and show evaluation results based on a set of composite service requests. The results show that our proposed method performs effectively in decomposing a composite service requests to a number of sub-requests and finding and matching service components that can fulfill the service composition request.

  • Marques P, Rodriguez J, Delaere S, Delahaye P, Lecroart B, Gundlach M, Triantafyllopoulou D, Moessner K, Noguet D. (2013) 'Spectrum sharing in the EU and the path towards standardization'. Lisbon, Portugal: Future Network and Mobile Summit (FutureNetworkSummit) 2013
  • Marques P, Rodriguez J, Delaere S, Gundlach M, Triantafyllopoulou D, Moessner K, Delahaye P, Lecroart B, Noguet D. (2013) 'Shared use of radio spectrum in the EU: from research projects to standards'. Budapest, Hungary: IEEE International Conference on Communications (ICC) 2013 - Second IEEE Workshop on Telecommunication Standards: From Research to Standards, pp. 1249-1254.
  • Francois F, Wang N, Moessner K, Georgoulas S, Xu K. (2013) 'Green IGP Link Weights for Energy-efficiency and Load-balancing in IP Backbone Networks'. Brooklyn, New York, USA: IFIP Networking 2013

    Abstract

    The energy consumption of backbone networks has become a primary concern for network operators and regulators due to the pervasive deployment of wired backbone networks to meet the requirements of bandwidth-hungry applications. While traditional optimization of IGP link weights has been used in IP based load-balancing operations, in this paper we introduce a novel link weight setting algorithm, the Green Load-balancing Algorithm (GLA), which is able to jointly optimize both energy efficiency and load-balancing in backbone networks. Such a scheme can be directly applied on top of existing link sleeping techniques in order to achieve substantially improved energy saving gains. The contribution is a practical solution that opens a new dimension of energy efficiency optimization, but without sacrificing traditional traffic engineering performance in plain IP routing environments. In order to evaluate the efficiency of the proposed optimization scheme without losing generality, we applied it to a set of recently proposed but diverse algorithms for link sleeping operations in the literature. Evaluation results based on the European academic network topology, GÉANT, and its real traffic matrices show that GLA can achieve significantly improved energy efficiency compared to the original standalone algorithms, while also maintaining near-optimal load-balancing performance.

  • Triantafyllopoulou D, Moessner K, Kliks A, Bogucka H, Zalonis A, Dagres I, Dimitriou N, Polydoros A. (2013) 'A Context-Aware Decision Making Framework for Cognitive and Coexisting Networking Environments'. VDE Verlag 19th European Wireless Conference, Guildford, United Kingdom: 19th European Wireless 2013
  • Durowoju O, Gronsund P, Moessner K. (2013) 'Distributed power control for secondary spectrum trading with incumbent protection'. IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC, , pp. 56-60.
  • Ibrahim A, Carrez F, Moessner K. (2013) 'Spatio-Temporal Model for Role Assignment in Wireless Sensor Networks.'. VDE-Verlag EW,
  • Oredope A, Moessner K, Peoples C, Parr G. (2013) 'Deploying cloud services in mobile networks'. Proceedings of 2013 Science and Information Conference, SAI 2013, , pp. 928-933.
  • Reetz ES, Kuemper D, Moessner K, Tonjes R. (2013) 'How to test IoT-based services before deploying them into real world'. 19th European Wireless Conference, EW 2013,
  • Alnwaimi G, Zahir T, Vahid S, Moessner K. (2013) 'Machine learning based knowledge acquisition on spectrum usage for LTE femtocells'. IEEE Vehicular Technology Conference,
  • Peoples C, Parr G, Oredope A, Moessner K. (2013) 'The standardisation of cloud computing: Trends in the state-of-the-art and management issues for the next generation of cloud'. Proceedings of 2013 Science and Information Conference, SAI 2013, , pp. 902-911.

    Abstract

    Roll-out of future cloud systems will be influenced by regulations from the standardisation bodies, if made available across the community. Trends in cloud deployment, operation and management to date have not been guided by any regulatory standards, and resources have been deployed in an ad hoc manner as demanded according to the business objectives of service providers. This is the least costly and most quickly revenue-returning business model. It is not however, the most cost-effective approach on a long-term basis: As a consequence of this roll-out model to date, the interoperability of resources deployed across clouds managed by different operators is restricted through inability to allocate workload to them in a regulated and controllable manner. The absence of standardised approaches to cloud management is therefore beginning to be accommodated such that the cost and performance advantages of interoperable operation may be exploited. In this paper, we review the state-of-the-art in standards across the field and trends in their development. We present a model which defines the drivers for cloud interoperability and constraints which restrict the extent to which this may realistically occur in future scalable solutions. This is supplemented with discussion on future challenges foreseen with regard to cloud operation and the way in which standards require provision such that cloud interoperation may be accommodated. © 2013 The Science and Information Organization.

  • Durowoju O, Arshad K, Moessner K. (2013) 'Distributed power control and user selection algorithms for cognitive radios'. IEEE Vehicular Technology Conference,
  • Lopez-Benitez M, Moessner K. (2013) 'LTE uplink extension in TV white spaces'. 19th European Wireless Conference, EW 2013,
  • Oredope A, McConnell A, Peoples C, Singh R, Gonsalves TA, Moessner K, Parr GP. (2013) 'Cloud Services in Mobile Environments - The IU-ATC UK-India Mobile Cloud Proxy Function.'. VDE-Verlag EW,
  • Triantafyllopoulou D, Guo T, Moessner K. (2012) 'Energy Efficient ANDSF-assisted Network Discovery for non-3GPP Access Networks'. IEEE Barcelona, Spain: IEEE International Workshop on Computer-Aided Modeling Analysis and Design of Communication Links and Networks (CAMAD), pp. 297-301.
  • Pérez-Romero J, Sallent O, Bouali F, Sarvanko H, Mustonen M, Matinmikko M, Lee H, Vahid S, Moessner K. (2012) 'A spectrum selection framework for Opportunistic Networks'. 2012 Future Network and Mobile Summit, FutureNetw 2012,
  • Tönjes R, Reetz ES, Moessner K, Barnaghi PM. (2012) 'A test-driven approach for life cycle management of internet of things enabled services'. 2012 Future Network and Mobile Summit, FutureNetw 2012,

    Abstract

    To date implementations of Internet of Things (IoT) architectures are confined to particular application areas and tailored to meet only the limited requirements of their narrow applications. To overcome technology and sector boundaries this paper proposes a dynamic service creation environment that employs i) orchestration of business services based on re-usable IoT service components, ii) self-management capable components for automated configuration and testing of services for things, and iii) abstraction of the heterogeneity of underlying technologies to ensure interoperability. To ensure reliability and robustness the presented approach integrates self-testing and self-adaptation in all service life cycle phases. The service life cycle management distinguishes the IoT service creation phase (design-time) and the IoT service provision phase (run-time). For test-friendly service creation (1) semantic service descriptions are employed to derive semi-automatically services and related tests, (2) and testing is systematically integrated into a Service Creation Environment. For reliable and robust service provisioning the presented system (3) forces validation tests in a sandbox environment before deployment and (4) enables run-time monitoring for service adaptation. The system under test is modelled by finite state machines (FSM) that are semi-automatically composed of re-usable test components. Then path searching algorithms are applied to derive automatically tests from the FSM model. The resulting tests are specified in the test control notation TTCN-3 and compiled to run the validation tests. © 2012 IIMC Ltd.

  • Chen Y, De S, Kernchen R, Moessner K. (2012) 'Device discovery in future service platforms through SIP'. IEEE Vehicular Technology Conference,
  • Georgoulas S, Moessner K, Eracleous D, Nati M. (2012) 'Formal Verification of the Cooperative Behaviour of Network Nodes for Routing and Context Dissemination'. IEEE Future Network & Mobile Summit (FutureNetw), 2012, Berlin, Germany: Future Network and Mobile Summit 2012
  • Chen Y, De S, Kernchen R, Moessner K. (2012) 'Device discovery in future service platforms through SIP'. IEEE Quebec City, Canada: IEEE Vehicular Technology Conference (VTC Fall), 2012, pp. 1-5.

    Abstract

    This paper proposes an extension to Session Initiation Protocol (SIP) for contextualized service delivery in a service delivery platform (SDP) that enables device specific multimedia delivery. SIP separates between session establishment and description and is thus, amenable to be extended for advanced implementations which make it an ideal platform for service creation. Device specific multimedia delivery needs rich and flexible device descriptions, and our approach proposes advanced device descriptions through semantic technologies. The proposed SIP extensions have been implemented on a SIP Application Server which functions as SDP in IP Multimedia Subsystem (IMS). The validation of the proposed extensions is shown through an Android SIP client application that acts as a device browser and recommender for different multimedia services to users. An example device user agent (UA) application has also been implemented on a laptop.

  • Wang W, De S, Toenjes R, Reetz E, Moessner K. (2012) 'A Comprehensive Ontology for Knowledge Representation in the Internet of Things'. IEEE Liverpool, UK: IEEE 11th International Conference on Trust, Security and Privacy in Computing and Communications (TrustCom), pp. 1793-1798.

    Abstract

    Semantic modeling for the Internet of Things has become fundamental to resolve the problem of interoperability given the distributed and heterogeneous nature of the “Things”. Most of the current research has primarily focused on devices and resources modeling while paid less attention on access and utilisation of the information generated by the things. The idea that things are able to expose standard service interfaces coincides with the service oriented computing and more importantly, represents a scalable means for business services and applications that need context awareness and intelligence to access and consume the physical world information. We present the design of a comprehensive description ontology for knowledge representation in the domain of Internet of Things and discuss how it can be used to support tasks such as service discovery, testing and dynamic composition.

  • Francois F, Wang N, Moessner K, Georgoulas S. (2012) 'Optimization for time-driven link sleeping reconfigurations in ISP backbone networks'. Proceedings of the 2012 IEEE Network Operations and Management Symposium, NOMS 2012, , pp. 221-228.

    Abstract

    Backbone network energy efficiency has recently become a primary concern for Internet Service Providers and regulators. The common solutions for energy conservation in such an environment include sleep mode reconfigurations and rate adaptation at network devices when the traffic volume is low. It has been observed that many ISP networks exhibit regular traffic dynamicity patterns which can be exploited for practical time-driven link sleeping configurations. In this work, we propose a joint optimization algorithm to compute the reduced network topology and its actual configuration duration during daily operations. The main idea is first to intelligently remove network links using a greedy heuristic, without causing network congestion during off-peak time. Following that, a robust algorithm is applied to determine the window size of the configuration duration of the reduced topology, making sure that a unified configuration with optimized energy efficiency performance can be enforced exactly at the same time period on a daily basis. Our algorithm was evaluated using on a Point-of-Presence representation of the GÉANT network and its real traffic matrices. According to our simulation results, the reduced network topology obtained is able to achieve 18.6% energy reduction during that period without causing significant network performance deterioration. The contribution from this work is a practical but efficient approach for energy savings in ISP networks, which can be directly deployed on legacy routing platforms without requiring any protocol extension. © 2012 IEEE.

  • Lee H, Vahid S, Moessner K. (2012) 'Utility-based dynamic spectrum aggregation algorithm in cognitive radio networks'. IEEE Vehicular Technology Conference,
  • Yu X, Navaratnam P, Moessner K. (2012) 'Distributed Interference Aware Admission Control with Soft Resource Allocation for Hybrid MAC in Wireless Mesh Networks'. IEEE ICC 2012, Ottawa, Canada: IEEE ICC 2012, pp. 460-465.
  • Gürgen L, Biswas AR, Moessner K, Ramparany F. (2012) 'Welcome message from the chairs'. Self-IoT'12 - Proceedings of the 2012 International Workshop on Self-Aware Internet of Things, Co-located with ICAC'12,
  • Guo T, Moessner K. (2012) 'Optimal strategy for QoS provision under spectrum mobility in cognitive radio networks'. IEEE IEEE Vehicular Technology Conference, Quebec City, QC: Vehicular Technology Conference (VTC Fall), 2012, pp. 1-5.
  • Guo T, Moessner K. (2012) 'Optimal strategy for QoS provision under spectrum mobility in cognitive radio networks'. IEEE Vehicular Technology Conference,

    Abstract

    In cognitive radio networks, the arrival of Primary Users (PUs) may force Secondary Users (SUs) to terminate their ongoing sessions or degrade their Quality of Service (QoS) level. Given the time-varying spectrum availability, an immediate challenge arising is to support the QoS of SUs under spectrum mobility. In this paper, we propose an optimal decision-making framework for joint admission control, eviction control and bandwidth adaptation in cognitive radio networks. The problem is formulated as a Semi-Markov Decision Process (SMDP) and the optimal decision for each system state is derived to maximize the long-term network revenue as a function of the spectrum utilization, the SU blocking probability and the bandwidth adaptation cost under the SU dropping probability constraint. It is shown that the derived optimal strategy outperforms the threshold-based channel reservation schemes with/without bandwidth adaptation. And among the schemes with bandwidth adaptation, more performance improvement can be achieved by the proposed one when the bandwidth adaptation cost is taken into account. © 2012 IEEE.

  • Yu X, Navaratnam P, Moessner K. (2012) 'Distributed interference-aware admission control with soft resource allocation for hybrid MAC in wireless mesh networks'. IEEE International Conference on Communications, , pp. 455-460.
  • Yu X, Navaratnam P, Moessner K. (2012) 'Distributed MAC scheduling mechanism based on resource reservation for IEEE 802.11e-based multi-hop wireless networks'. IEEE Wireless Communications and Networking Conference, WCNC, , pp. 1782-1787.
  • Lee H, Vahid S, Moessner K. (2012) 'Utility-based dynamic spectrum aggregation algorithm in cognitive radio networks'. IEEE Vehicular Technology Conference,
  • Godarzi DM, Arshad K, Ko Y, Moessner K. (2012) 'Selecting users in energy-efficient collaborative spectrum sensing'. IEEE Wireless Communications and Networking Conference, WCNC, , pp. 1029-1033.
  • Cassar G, Barnaghi P, Wang W, Moessner K. (2012) 'A hybrid semantic matchmaker for IoT services'. Proceedings - 2012 IEEE Int. Conf. on Green Computing and Communications, GreenCom 2012, Conf. on Internet of Things, iThings 2012 and Conf. on Cyber, Physical and Social Computing, CPSCom 2012, , pp. 210-216.

    Abstract

    The use of semantic Web technologies and service oriented computing paradigm in Internet of Things research has recently received significant attention to create a semantic service layer that supports virtualisation of and interaction among "Things". Using service-based solutions will produce a deluge of services that provide access to different data and capabilities exposed by different resources. The heterogeneity of the resources and their service attributes, and dynamicity of mobile environments require efficient solutions that can discover services and match them to the data and capability requirements of different users. Semantic service matchmaking process is the fundamental construct for providing higher level service-oriented functionalities such as service recommendation, composition, and provisioning in Internet of Things. However, scalability of the current approaches in dealing with large number of services and efficiency of logical inference mechanisms in processing huge number of heterogeneous service attributes and metadata are limited. We propose a hybrid semantic service matchmaking method that combines our previous work on probabilistic service matchmaking using latent semantic analysis with a weighted-link analysis based on logical signature matching. The hybrid method can overcome most cases of semantic synonymy in semantic service description which usually presents the biggest challenge for semantic service matchmakers. The results show that the proposed method performs better than existing solutions in terms of precision (P@n) and normalised discounted cumulative gain (NDCGn) measurement values. © 2012 IEEE.

  • Gürgen L, Biswas A-R, Moessner K, Ramparany F. (2012) 'Welcome message from the chairs'. Self-IoT'12 - Proceedings of the 2012 International Workshop on Self-Aware Internet of Things, Co-located with ICAC'12,
  • Alshahwan F, Moessner K, Carrez F. (2011) 'Distribute provision strategies of RESTful-based mobile web services'. IEEE IEEE Global Telecommunications Conference 2011, Houston, Texas: GLOBECOM 2011
  • Nakata A, Arshad K, Moessner K. (2011) 'Interference Tolerable Threshold Analysis in Cognitive Femtocells'. Washington DC, USA: Wireless Innovation Conference and Product Exhibition (SDR'11-WinnComm)

    Abstract

    In this paper interference management in co-channel deployment of macrocell and cognitive femtocells is investigated. For the purpose of the aggregate interference mitigation from all femtocell access points (FAP) to macrocell user equipment (MUE) and the purpose to increase the radio link quality of femtocell system, a parameter named interference tolerable threshold (Ith) is introduced, the aim is to reduce the interference an individual FAP causes to MUE to a level lower than Ith. A dynamic Ith control scheme is proposed to determine the appropriate value of this threshold. The simulation results show that the highest available Ith depends on the total number of FAPs, a larger number of FAPs does affect aggregate interference even if the individual interference is in acceptable range. The proposed method, however, achieves the adaptation of the highest available Ith without needing knowledge about the number of FAPs in the vicinity of MUEs.

  • Arshad K, Briggs K, Moessner K. (2011) 'Robust spectrum sensing for cognitive radio based on statistical tests'. ACM Proceedings of the 4th International Conference on Cognitive Radio and Advanced Spectrum Management, Barcelona, Spain: CogART 2011
  • Ayyadurai V, Moessner K, Tafazolli R. (2011) 'Multihop cellular network optimization using genetic algorithms'. 2011 7th International Conference on Network and Service Management, Paris, France: 7th CNSM
  • Ganz F, Barnaghi P, Carrez F, Moessner K. (2011) 'Context-aware management for sensor networks'. New York, USA : ACM Proceedings of the 5th International Conference on Communication System Software and Middleware, Verona, Italy: COMSWARE 2011, pp. 6:1-6:6.

    Abstract

    The wide field of wireless sensor networks requires that hun- dreds or even thousands of sensor nodes have to be main- tained and configured. With the upcoming initatives such as Smart Home and Internet of Things, we need new mecha- nism to discover and manage this amount of sensors. In this paper, we describe a middleware architecture that uses con- text information of sensors to supply a plug-and-play gate- way and resource management framework for heterogeneous sensor networks. Our main goals are to minimise the effort for network engineers to configure and maintain the network and supply a unified interface to access the underlying het- erogeneous network. Based on the context information such as battery status, routing information, location and radio signal strength the gateway will configure and maintain the sensor network. The sensors are associated to nearby base stations using an approach that is adapted from the 802.11 WLAN association and negotiation mechanism to provide registration and connectivity services for the underlying sen- sor devices. This abstracted connection layer can be used to integrate the underlying sensor networks into high-level ser- vices and applications such as IP-based networks and Web services.

  • Arshad K, Moessner K. (2011) 'Robust collaborative spectrum sensing based on beta reputation system'. 2011 Future Network and Mobile Summit, Warsaw, Poland: Future Network Summit 2011
  • Guo T, Wang N, Moessner K, Tafazolli R. (2011) 'Shared backup network provision for virtual network embedding'. IEEE International Conference on Communications,

    Abstract

    Network virtualization has been recognized as a promising solution to enable the rapid deployment of customized services by building multiple Virtual Networks (VNs) on a shared substrate network. Whereas various VN embedding schemes have been proposed to allocate the substrate resources to each VN requests, little work has been done to provide backup mechanisms in case of substrate network failures. In a virtualized infrastructure, a single substrate failure will affect all the VNs sharing that resource. Provisioning a dedicated backup network for each VN is not efficient in terms of substrate resource utilization. In this paper, we investigate the problem of shared backup network provision for VN embedding and propose two schemes: shared on-demand and shared pre-allocation backup schemes. Simulation experiments show that both proposed schemes make better utilization of substrate resources than the dedicated backup scheme without sharing, while each of them has its own advantages. © 2011 IEEE.

  • Durowoju O, Arshad K, Moessner K. (2011) 'Distributed power control for cognitive radio networks, based on incumbent outage information'. IEEE International Conference on Communications,
  • Arshad K, Moessner K. (2011) 'Efficient spectrum management among spectrum sharing UMTS operators'. IEEE Vehicular Technology Conference,
  • Yu X, Navaratnam P, Moessner K. (2011) 'Distributed resource reservation for real time sessions in multi-hop wireless networks'. IWCMC 2011 - 7th International Wireless Communications and Mobile Computing Conference, , pp. 255-260.
  • AlShahwan F, Moessner K, Carrez F. (2011) 'Distributing resource intensive mobile web services'. 2011 International Conference on Innovations in Information Technology, IIT 2011, , pp. 41-46.
  • Cassar G, Barnaghi P, Moessner K. (2011) 'A probabilistic latent factor approach to service ranking'. Proceedings - 2011 IEEE 7th International Conference on Intelligent Computer Communication and Processing, ICCP 2011, , pp. 103-109.
  • Durowju O, Arshad K, Moessner K. (2011) 'Cognitive time variant power control in slow fading mobile channels'. IEEE Vehicular Technology Conference,
  • Yu X, Navaratnam P, Moessner K. (2011) 'Delay model for super frame based resource reservation in distributed wireless networks'. SpringerLink MobiMedia 2011 - Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 2012, Cagliari, Italy: International Mobile Multimedia Communications Conference - MobiMedia 2011 79, pp. 89-104.
  • Mcaleer B, Georgoulas S, Moessner K, Tafazolli R. (2011) 'Evaluating protocol energy use and efficiency through profiling of computational operations'. IWCMC 2011 - 7th International Wireless Communications and Mobile Computing Conference, , pp. 930-935.
  • Zahir T, Arshad K, Ko Y, Moessner K. (2011) 'A downlink power control scheme for interference avoidance in femtocells'. IWCMC 2011 - 7th International Wireless Communications and Mobile Computing Conference, , pp. 1222-1226.
  • Jin Y, Wei D, Vural S, Gluhak A, Moessner K. (2011) 'A distributed energy-efficient re-clustering solution for wireless sensor networks'. GLOBECOM - IEEE Global Telecommunications Conference,
  • Alnwaimi G, Arshad K, Moessner K. (2011) 'Dynamic spectrum allocation algorithm with interference management in displaced networks'. IWCMC 2011 - 7th International Wireless Communications and Mobile Computing Conference, , pp. 941-946.
  • AlShahwan F, Moessner K, Carrez F. (2011) 'Providing light weight distributed web services from mobile hosts'. Proceedings - 2011 IEEE 9th International Conference on Web Services, ICWS 2011, , pp. 652-659.
  • Georgoulas S, Ghader M, Moessner K, Dianati M, Tafazolli R. (2011) 'On the applicability of architecture description languages to future internet networking environments'. Warsaw, Poland: Future Network and Mobile summit 2011
  • Arshad K, Moessner K. (2011) 'Statistical models of spectrum opportunities for cognitive radio'. IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC, , pp. 2310-2314.
  • Ganz F, Barnaghi P, Carrez F, Moessner K. (2011) 'A mediated gossiping mechanism for large-scale sensor networks'. 2011 IEEE GLOBECOM Workshops, GC Wkshps 2011, , pp. 405-409.

    Abstract

    Gateways in sensor networks are used to relay, aggregate and communicate information from capillary networks to more capable (e.g. IP-based) networks. However Gateway-to-Gateway (G2G) communication to exchange and update information among the gateways in large-scale sensor networks for query processing, data fusion and other similar tasks has been less discussed in recent works. The requirements for large-scale sensor networks such as dynamic topology and update strategies to reduce the overall network load makes G2G communications an important aspect in the network design. In this paper, we introduce a mediated gossip-based G2G communication mechanism. The proposed solution leverages the publish/subscribe approach and uses high-level context assigned to publish/subscribe channels to enable the information discovery and G2G communications. Gateways store/aggregate sensor observation and measurement data according to specific context which is defined based on features such as spatial and temporal attributes, observed phenomena (i.e. feature of interest) and sensor device features. The gateways communicate with each other to exchange data and also to forward related queries for data aggregation in cases that the data should be aggregated from two different sources. The proposed solution also facilitates reliable sensor service provisioning by enabling gateways to communicate and/or forward requests to other gateways when a resource fails or a sensor node becomes unavailable. We compare our results to probabilistic gossiping algorithms and run benchmarks on different dynamic network topologies based on indicators such as number of sent messages and dissemination delay. © 2011 IEEE.

  • Elsaleh T, Gluhak A, Moessner K. (2011) 'Service continuity for subscribers of the mobile real world Internet'. IEEE International Conference on Communications,
  • De Silva H, Carrez F, Moessner K. (2011) 'Automated group formation in decentralised environments'. IEEE International Conference on Intelligent Systems Design and Applications, ISDA, , pp. 24-29.

    Abstract

    Collaboration towards a goal involves groups of entities collectively possessing characteristics required to accomplish the goal. Facilitating collaborations in pervasive environments requires the automated formation of such groups. The group formation process is especially challenging in decentralised environments where there is no single central entity that can coordinate the formation process. It is also important that the group formation mechanisms are generic in nature so that they can be utilised in heterogeneous target environments regardless of their domain and requirements. This paper proposes a generic approach for automating group formation in decentralised environments. © 2011 IEEE.

  • Barnaghi P, Cassar G, Moessner K. (2010) 'Probabilistic Methods for Service Clustering'. CEUR Workshop Proceedings: Proceedings of 4th International Workshop on Service Matchmaking and Resource Retrieval in the Semantic Web, Shanghai, China: SMR2 2010 667

    Abstract

    This paper focuses on service clustering and uses service descriptions to construct probabilistic models for service clustering.We discuss how service descriptions can be enriched with machine-interpretable semantics and then we investigate how these service descriptions can be grouped in clusters in order to make discovery, ranking, and recommendation faster and more effective. We propose using Probabilistic Latent Semantic Analysis (PLSA) and Latent Dirichlet Allocation (LDA) (i.e. two machine learning techniques used in Information Retrieval) to learn latent factors from the corpus of service descriptions and group services according to their latent factors. By creating an intermediate layer of latent factors between the services and their descriptions, the dimensionality of the model is reduced and services can be searched and linked together based on probabilistic methods in latent space. The model can cluster any newly added service with a direct calculation without requiring to re-calculate the latent variables or re-train the model.

  • Barnaghi P, Liu X, Moessner K, Liao J. (2010) 'Using Concept and Structure Similarities for Ontology Integration'. CEUR Workshop Proceedings: Proceedings of the 5th International Workshop on Ontology Matching, Shanghai, China: OM-2010 689

    Abstract

    We propose a method to align different ontologies in similar domains and then define correspondence between concepts in two different ontologies using the SKOS model.

  • Georgoulas S, Moessner K, Mcaleer B, Tafazolli R. (2010) 'Using formal verification methods and tools for protocol profiling and performance assessment in mobile and wireless environments'. IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC, , pp. 2471-2476.
  • Chantaraskul S, Moessner K. (2010) 'Experimental study of multi-resolution spectrum opportunity detection using wavelet analysis'. 2010 IEEE Symposium on New Frontiers in Dynamic Spectrum, DySPAN 2010,
  • Durowoju O, Arshad K, Moessner K. (2010) 'Distributed Power Control for Cognitive Radios with Primary Protection via Spectrum Sensing'. Proc. IEEE 72nd Vehicular Technology Conf. Fall (VTC 2010-Fall), , pp. 1-5.
  • Guo T, Wang N, Tafazolli R, Moessner K. (2010) 'Policy-Aware Virtual relay placement for inter-domain path diversity'. Proc. IEEE Symp. Computers and Communications (ISCC), , pp. 38-43.
  • Rodriguez J, Marques P, Radwan A, Moessner K, Tafazolli R, Raspopoulos M, Stavrou S, Trapps P, Noquet D, Sithamparanathan K, Gomes A, Piesiewicz R, Mokrani H, Foglar A, Verikoukis C. (2010) 'Cognitive radio and cooperative strategies for power saving in multi-standard wireless devices'. 2010 Future Network and Mobile Summit,
  • Wei D, Jin Y, Gluhak A, Tafazolli R, Moessner K. (2010) 'Hot-spot issue aware clustering for WSNs to extend stable operation period'. 2010 Future Network and Mobile Summit,
  • Georgoulas S, Moessner K, McAleer B, Tafazolli R. (2010) 'Towards efficient protocol design through protocol profiling and verification of performance and operational metrics'. IWCMC 2010 - Proceedings of the 6th International Wireless Communications and Mobile Computing Conference, , pp. 848-852.
  • Yu X, Navaratnam P, Moessner K. (2010) 'Distributed Resource Reservation Mechanism for IEEE 802.11e-Based Networks'. Proc. IEEE 72nd Vehicular Technology Conf. Fall (VTC 2010-Fall), Ottawa: IEEE 72nd Vehicular Technology Conference, pp. 1-5.
  • Deschamps B, Moessner K, Smith B. (2010) 'Regulation requirements of advanced spectrum exploitation technologies'. 2010 Future Network and Mobile Summit,
  • Dianati M, Tafazolli R, Moessner K. (2010) 'Enabling Tussle-Agile Inter-networking Architectures by Underlay Virtualisation'. SPRINGER-VERLAG BERLIN FUTURE INTERNET - FIS 2009, Berlin, GERMANY: 2nd Future Internet Symposium (FIS 2009) 6152, pp. 81-95.
  • Jin Y, Wei D, Gluhak A, Moessner K. (2010) 'Latency and energy-consumption optimized task allocation in wireless sensor networks'. IEEE Wireless Communications and Networking Conference, WCNC,
  • Arshad K, Moessner K. (2010) 'Mobility driven energy detection based spectrum sensing framework of a cognitive radio'. Proceedings - 2010 2nd UK-India-IDRC International Workshop on Cognitive Wireless Systems, UKIWCWS 2010,
  • De S, Attou A, Moessner K. (2009) 'Service and Content Presentation in Ubiquitous Environments'. Springer Guildford, UK: 4th European Conference on Smart Sensing and Context (EuroSSC), pp. 61-64.

    Abstract

    The heterogeneous, dynamic nature of ubiquitous environments necessitates that all system components that form part of a personalisation framework should be context aware. Personalised service delivery requires that the system must detect and interpret device modality contexts in real time and provide automated adaptation on behalf of the user. Towards this aim, this paper presents the design and implementation of a demonstrator that offers personalised, context sensitive, service and content delivery.

  • De S, Moessner K. (2009) 'A Framework for Mobile, Context-Aware Applications'. IEEE 2009 INTERNATIONAL CONFERENCE ON TELECOMMUNICATIONS (ICT), Marrakech, MOROCCO: 16th International Conference on Telecommunications (ICT), pp. 232-237.
  • Arshad K, Moessner K. (2009) 'Collaborative Spectrum Sensing for Cognitive Radio'. IEEE 2009 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATION WORKSHOPS, VOLS 1 AND 2, Dresden, GERMANY: IEEE International Conference on Communications (ICC 2009), pp. 371-375.
  • De S, Moessner K. (2009) 'Rule-based Reasoning Mechanism for Context-aware Service Presentation'. IIMC International Information Management Corporation Ltd eChallenges e-2009 Conference Proceedings, Istanbul, Turkey: eChallenges e-2009

    Abstract

    With universal usability geared towards user focused customisation, a context reasoning engine can derive meaning from the various context elements and facilitate decision-taking for applications and context delivery mechanisms. The heterogeneity of available device capabilities means that the recommendation algorithm must be in a formal, effective and extensible form. Moreover, user preferences, capability context and media metadata must be considered simultaneously to determine appropriate presentation format. Towards this aim, this paper presents a reasoning mechanism that supports service presentation through a rule-based mechanism. The validation of the approach is presented through application use cases.

  • Alnwaimi G, Arshad K, Moessner K. (2009) 'Collaborative spectrum sensing in OFDM-based Cognitive Radio'. Proceedings - 2009 1st UK-India International Workshop on Cognitive Wireless Systems, UKIWCWS 2009,
  • Arshad K, Moessner K. (2009) 'Collaborative spectrum sensing: Optimising the number of collaborating users'. Proceedings - 2009 1st UK-India International Workshop on Cognitive Wireless Systems, UKIWCWS 2009,
  • Li N, Attou A, De S, Moessner K. (2008) 'Device and service descriptions for ontology-based ubiquitous multimedia services'. MoMM2008 - The 6th International Conference on Advances in Mobile Computing and Multimedia, , pp. 370-375.
  • De S, Moessner K. (2008) 'Semantic Description of Multimodal Devices: Modelling and Evaluation'. IOS Press Collaboration and the Knowledge Economy: Issues, Applications and Case Studies, Stockholm, Sweden: eChallenges e-2008 5, pp. 1439-1446.

    Abstract

    The heterogeneous, dynamic nature of current communication environments necessitates that all system components that form part of a personalisation framework should be context aware. To ensure context enabled interoperation, a shared, formalised specification of devices and services in the ambient environment is a must. With this aim, this paper presents an ontology model that captures the semantics of the multimodal devices and services in the mobile ad-hoc environment. The approach is validated using available metrics and compared to existing approaches, both through subjective feature-based evaluation and metrics’ calculations. This paper also extends the metrics’ usability by extending the analysis to interoperability with application logic and domain capture.

  • De S, Moessner K. (2008) 'Ontology "based context inference and query for mobile devices'. IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC,
  • De S, Meissner S, Kernchen R, Moessner K. (2008) 'A Semantic Device and Service Description Framework for Ubiquitous Environments'. IIMC International Information Management Corporation ICT-MobileSummit 2008 Conference Proceedings, Stockholm, Sweden: 17th ICT Mobile and Wireless Communications Summit Conference
  • Attou A, Li N, Moessner K. (2008) 'Context for multimedia services adaptation'. MOBIMEDIA 2008 - 4th International ICST Mobile Multimedia Communications Conference,
  • Zhdanova AV, Davies M, Jorns O, Stavroulaki V, Demestichas P, Gonzalez M, Moessner K, Carrez F, Rajasekaran H, Iacono LL. (2008) 'MOSS: Mobile social spaces'. CEUR Workshop Proceedings, 409
  • Attou A, Ding J, Laurenson DI, Moessner K. (2008) 'Performance Modelling and Evaluation of An Adaptation Management System'. SOC MODELING SIMULATION INT-SCS PROCEEDINGS OF THE 2008 INTERNATIONAL SYMPOSIUM ON PERFORMANCE EVALUATION OF COMPUTER AND TELECOMMUNICATION SYSTEMS, Edinburgh, SCOTLAND: International Symposium on Performance Evaluation Computer and Telecommunication Systems, pp. 369-376.
  • Akhtar N, Moessner K. (2008) 'Capacity of grid-oriented wireless mesh networks'. IEEE 2008 3RD INTERNATIONAL CONFERENCE ON COMMUNICATION SYSTEM SOFTWARE AND MIDDLEWARE AND WORKSHOPS, VOLS 1 AND 2, Bangalore, INDIA: 3rd International Conference on Communication System Software and Middleware and Workshop, pp. 631-636.
  • Akhtar N, Markendahl J, Moessner K. (2007) 'Analysis of complexity and transaction costs for cooperating networks'. IEEE 2007 IEEE 18TH INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR AND MOBILE RADIO COMMUNICATIONS, VOLS 1-9, Athens, GREECE: 18th IEEE International Symposium on Personal, Indoor and Mobile Radio Communication, pp. 4270-4274.
  • Grandblaise D, Moessner K, Vivier G, Tafazolli R. (2007) 'Credit token based rental protocol for dynamic channel allocation'. 1st International Conference on Cognitive Radio Oriented Wireless Networks and Communications 2006, CROWNCOM,

    Abstract

    This paper describes a distributed, cooperative and real time rental protocol for DCA operations in a multi system and mult) cell context for OFDMA systems. A credit token based rental protocol using auctioning Is proposed in support of dynamic spectrum sharing between cells. The proposed scheme can be tuned adaptively as a function of the context by specifying the credit tokens usage in the radio etiquette. The application of the rental protocol is illustrated with an ascending bid auctioning. The paper also describes two approaches for BS-BS communications in support of the rental protocol. Finally, it is described how the proposed mechanisms contribute to the current approaches followed in the IEEE 802.16h and IEEE 802.22 standards efforts addressing cognitive radio, © 2006 IEEE.

  • De S, Moessner K. (2007) 'Context gathering in Ubiquitous Environments: Enhanced Service Discovery'. 3rd Workshop on Context Awareness for Proactive Systems (CAPS'2007) Proceedings, Guildford, UK: 3rd Workshop on Context Awareness for Proactive Systems (CAPS'2007)

    Abstract

    Delivering individualized services that conform to the user’s current situation will form the focus of ubiquitous environments. A description of the networked environment at a semantic level will necessitate contextually oriented knowledge acquisition methods. This then engenders unique challenges for the crucial step of resource discovery. A number of service discovery protocols exist to perform this role. In this paper, we identify the requirements inherent for such an environment and investigate the suitability of the available protocols against these. A suitable candidate solution is proposed with an implementation with semantic extensions and reference points for further enhancements.

  • Li N, Moessner K. (2007) 'The MVCE knowledge-based content and service adaptation management framework'. 7th International Workshop on Applications and Services in Wireless Networks, ASWN 2007,
  • Attou A, Moessner K. (2007) 'Context-aware service adaptation management'. IEEE 2007 IEEE 18TH INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR AND MOBILE RADIO COMMUNICATIONS, VOLS 1-9, Athens, GREECE: 18th IEEE International Symposium on Personal, Indoor and Mobile Radio Communication, pp. 1468-1472.
  • Thilakawardana D, Moessner K. (2007) 'A genetic approach to cell-by-cell dynamic spectrum allocation for optimising spectral efficiency in wireless mobile systems'. IEEE 2007 2ND INTERNATIONAL CONFERENCE ON COGNITIVE RADIO ORIENTED WIRELESS NETWORKS AND COMMUNICATIONS, Orlando, FL: 2nd International Conference on Cognitive Radio Oriented Wireless Networks and Communications, pp. 367-372.
  • Tarkoma S, Prehofer C, Zhdanova AV, Moessner K, Kovacs E. (2007) 'SPICE: Evolving IMS to next generation service platforms'. SAINT - 2007 International Symposium on Applications and the Internet - Workshops, SAINT-W,
  • Zhou D, Migault D, Wang Y, Akhtar N, Moessner K. (2007) 'Map of Relaying Messages (MORM) an approach of message distribution enabling network advertisement and discovery'. 2007 6th International Workshop on Design and Reliable Communication Networks, DRCN 2007,
  • Muck M, Bourse D, Moessner K, Alonistioti N, Demestichas P, Nicollet E, Buracchini E, Bateman D, Boufidis Z, Patouni E, Stavroulaki V, Trogolo A, Goria P. (2007) 'End-to-end reconfigurability in heterogeneous wireless systems - Software and cognitive radio solutions enriched by policy- and context-based decision making'. 2007 16th IST Mobile and Wireless Communications Summit,
  • Holland O, Muck M, Martigne P, Bourse D, Cordier P, Jemaa SB, Houze P, Grandblaise D, Klöck C, Renk T, Pan J, Slanina P, Mößner K, Giupponi L, Romero JP, Agusti R, Attar A, Aghvami AH. (2007) 'Development of a Radio enabler for reconfiguration management within the IEEE P1900.4 working group'. 2007 2nd IEEE International Symposium on New Frontiers in Dynamic Spectrum Access Networks, , pp. 232-239.
  • Du Y, Kertichen R, Moessner K, Raeck C, Sawade O, Tarkoma S, Arbanowski S. (2007) 'Context-aware learning for intelligent mobile multimodal user interfaces'. IEEE 2007 IEEE 18TH INTERNATIONAL SYMPOSIUM ON PERSONAL, INDOOR AND MOBILE RADIO COMMUNICATIONS, VOLS 1-9, Athens, GREECE: 18th IEEE International Symposium on Personal, Indoor and Mobile Radio Communication, pp. 3672-3676.
  • Grandblaise D, Moessner K, Vivier G, Tafazolli R. (2006) 'Rental protocol for automated spectrum sharing negotiation between base stations'. FACHVERLAG SCHIELE SCHON FREQUENZ, Karlsruhe, GERMANY: 4th Karlsruhe Workshop on Software Radios 60 (9-10), pp. 162-166.
  • Demestichas P, Dimitrakopoulos G, Mößner K, Dodgson T, Bourse D, Stavroulaki V, Malamateniou F, Katidiotis A, Tsagkaris K, El Khazen K, Grandblaise D, Beaujean C, Buljore S, Roux P, Vivier G, Hope S, Brakensiek J, Lenz D, Lucking U, Steinke B, Aghvami H, Olaziregi N, Holland O, Fan Q, Alonistioti N, Foukalas F, Kafounis K, Kaloxylos A, Stamatelatos M, Boufidis Z, Hoffmeyer J, Dillinger M, Mohyeldin E, Luo J, Schulz E, Falk R, Menzel C, Agusti R, Sallent O, Alvarez M, Garcia-Perez R, Campoy LM, Vila JE, Warzansky W, Bakaimis BA, Berlemann L, Mirkovic J, Bisiaux A, de Baynast A, Joseph MC, Cavallaro R, Radosavljevic P, Delautre A, Goubard JE, Farnham T, Zhong S, Dolwin C, Dornbush P, Fahrmair M, Gultchev S, Halimic M, Patel S, Naveen S, Vogler J, Pfeiffer G, Berzosa F, Wiebke T, Prehofer C, Wei Q, Pulou J, Stuckmann P, Cordier P, Lugara D, Ravasio G. (2006) 'Reconfigurability'. 2, pp. 313-421.
  • Akhtar N, Moessner K, Kernchen R. (2006) 'Context dissemination for Autonomic Communication systems'. SPRINGER-VERLAG BERLIN AUTONOMIC COMMUNICATION, Athens, GREECE: 2nd IFIP Workshop on Autonomic Communication (WAC 2005) 3854, pp. 237-242.
  • Moessner K, Luo J, Mohyeldin E, Grandblaise D, Kloeck C, Martoyo I, Sallent O, Demestichas P, Dimitrakopoulos G, Tsagkaris K, Olaziregi N. (2006) 'Functional Architecture of End-to-End Reconfigurable Systems'. IEEE 2006 IEEE 63RD VEHICULAR TECHNOLOGY CONFERENCE, VOLS 1-6, Melbourne, AUSTRALIA: 63rd IEEE Vehicular Technology Conference, pp. 196-200.
  • Gluhak A, Chew KA, Moessner K, Tafazolli R. (2005) 'Multicast bearer selection in heterogeneous wireless networks'. Proc. IEEE Int. Conf. Communications ICC 2005, 2, pp. 1372-1377.
  • Grandblaise D, Moessner K, Vivier G, Tafazolli R. (2005) 'Extended DCA paradigm for distributed licensed open spectrum coordination'. Proc. IEEE 16th Int. Symp. Personal, Indoor and Mobile Radio Communications PIMRC 2005, 3, pp. 1974-1978.
  • Kernchen R, Boda PP, Moessner K, Mrohs B, Boussard M, Giuliani G. (2005) 'Multimodal user interfaces for context-aware mobile applications'. Proc. IEEE 16th Int. Symp. Personal, Indoor and Mobile Radio Communications PIMRC 2005, 4, pp. 2268-2273.
  • Rodriguez V, Moessner K, Tafazolli R. (2005) 'Auction driven dynamic spectrum allocation: optimal bidding, pricing and service priorities for multi-rate, multi-class CDMA'. Proc. IEEE 16th Int. Symp. Personal, Indoor and Mobile Radio Communications PIMRC 2005, 3, pp. 1850-1854.
  • Grandblaise D, Kloeck C, Moessner K, Rodriguez V, Mohyeldin E, Pereirasamy MK, Luo J, Martoyo I. (2005) 'Techno - economic of collaborative based secondary spectrum usage - E2R research project outcomes overview'. Proc. First IEEE Int. Symp. New Frontiers in Dynamic Spectrum Access Networks DySPAN 2005, , pp. 318-327.
  • Ghader M, Moessner K, Tafazolli R. (2004) 'Service Discovery and Provision Protocols for Wireless Networks'. Lyon, France: 13th IST Mobile & Wireless Communications Summit
  • Moessner K, Bourse D, El-Khazen K, Grandblaise D. (2004) 'The responsibility chain in end-to end reconfigurable systems'. Proc. and the Symp Mobile Future Trends in Communications. SympoTIC ’04. Joint IST Workshop, , pp. 208-211.
  • Gultchev S, Moessner K, Tafazolli R, Anders J. (2004) 'Reconfigurable software based communication - video services in reconfigurable mobile devices'. Proc. Fifth IEE Int. Conf. 3G Mobile Communication Technologies 3G 2004, , pp. 422-426.
  • Fan L, Akhtar N, Chew KA, Moessner K, Tafazolli R. (2004) 'Network composition: a step towards pervasive computing'. Proc. Fifth IEE Int. Conf. 3G Mobile Communication Technologies 3G 2004, , pp. 198-202.
  • Gultchev S, Moessner K, Tafazolli R. (2003) 'Network based reconfiguration support services for software radio terminals'. Proc. 3G Mobile Communication Technologies 4th Int. Conf. (Conf. Publ. No. 494), , pp. 119-122.
  • Grandblaise D, Moessner K, Leaves P, Bourse D. (2003) 'Reconfigurability support for dynamic spectrum allocation: from the DSA concept to implementation'. Proc. Joint First Workshop Mobile Future and Symp. Trends in Communications SympoTIC ’03, , pp. 9-12.
  • Gultchev S, Mitchell C, Moessner K, Tafazolli R. (2002) 'Securing reconfigurable terminals - mechanisms and protocols'. Proc. 13th IEEE Int Personal, Indoor and Mobile Radio Communications Symp, 2, pp. 804-808.
  • Gultchev S, Moessner K, Tafazolli R. (2002) 'Controlling reconfiguration'. Proc. Third Int 3G Mobile Communication Technologies Conf. (Conf. Publ. No. 489), , pp. 474-478.
  • Moessner K, Gultchev S, Tafazolli R. (2001) 'Software defined radio reconfiguration management'. Proc. 12th IEEE Int Personal, Indoor and Mobile Radio Communications Symp, 1
  • Jefferies N, Irvine J, Munro A, Moessner K. (2001) 'Managing increasingly software dependent mobile systems'. Proc. Second Int 3G Mobile Communication Technologies Conf. (Conf. Publ. No. 477), , pp. 247-251.
  • Moessner K, Vahid S, Tafazolli R. (2001) 'Terminal reconfigureability-the OPTiMA framework'. Proc. Second Int 3G Mobile Communication Technologies Conf. (Conf. Publ. No. 477), , pp. 241-246.
  • Moessner K, Tafazolli R. (2000) 'Terminal reconfigureability-the software download aspect'. Proc. First Int 3G Mobile Communication Technologies Conf. (Conf. Publ. No. 471), , pp. 326-330.
  • Moessner K, Vahid S, Tafazolli R. (1999) 'Extension of the PNNI to support mobility management and handoffs in WATM networks based on CORBA'. Proc. IEEE 49th Vehicular Technology Conf, 3, pp. 2515-2519.
  • Moessner K, Vahid S, Tafazolli R. (1999) 'A minimum air interface implementation for software radio based on distributed object technology'. Proc. IEEE Int Personal Wireless Communication Conf, , pp. 369-373.

Books

  • Barnaghi P, Moessner K, Presser M, Meissner S. (2009) Smart Sensing and Context. Springer

Book chapters

  • De S, Zhou Y, Moessner K. (2017) 'Ontologies and context modeling for the Web of Things'. in Sheng M, Qin Y, Yao L, Benatallah B (eds.) Managing the Web of Things: Linking the Real World to the Web 1st Edition. Burlington, Massachusetts : Morgan Kaufmann Article number 1 , pp. 3-36.
    [ Status: In preparation ]
  • Triantafyllopoulou D, Moessner K, Alam M, Radwan A, Rodriguez J. (2014) 'Cognitive Means Smart: Knowledge Saves Power'. in Radwan A, Rodriguez J (eds.) Energy Efficient Smart Phones for 5G Networks Springer Article number 6

    Abstract

    The previous chapters mainly examined methods to save energy at the mobile handset, either by using short-range cooperation between mobile terminals, or by performing smart vertical handovers between heterogeneous radio access technologies. These techniques can be beneficial to mobile systems, but they have to be performed based on informed decisions; meaning that mobile devices need to be cognitive. Modern devices already collect significant amounts of information, but they have limited capability to exploit such context/information, and handover decisions are merely based on signal strength, or are network controlled and based on network load. In this chapter, we aim to go beyond the state-of-the-art by envisioning mobile terminals with the capability to make informed decisions based on a reservoir of context information made available through context providers; namely what is referred to as smart phones. We include a survey of the current state of the art for context extraction and management in context-aware systems; besides listing the current context extraction techniques and research efforts, we pinpoint the important properties of good context extraction techniques. Thereafter, we discuss how context information can be exploited in energy saving when performing network or node discovery mechanism, by instructing the mechanisms to scan for certain nodes/networks which are known to be in the vicinity. Finally, we discuss the range of context information that can be used to make informed decisions to save power.

  • Zhang Q, Moessner K. (2012) 'A context aware architecture for energy efficient cognitive radio'. 77 LNICST, pp. 452-462.

Patents

  • Moessner K, Attou A. (2008) Apparatus and Method for Performing Service Adaptation in Respect of a Mobile Computing Device.
  • De S, Moessner K. (2008) Method and apparatus for producing an ontology representing devices and services currently available to a device within a pervasive computing environment. US: Article number USPTO 12/062,794

Other publications

  • Itaya S, Kanhere S, Aust S, Alfandi O, Altintas O, Bochow B, Bohli JM, Boyle D, Chakraborty D, Chou CT, Davis P, Doi SI, Emmelmann M, Heemstra De Groot S, Iwaoka M, Konishi T, Krishnaswamy D, Marusic S, Moessner K, Mogre P, Prasad V, Rao VS, Saha D, Schülke A, Shinkuma R, Takai M, Yan Z, Dong AY, Headley W. (2013) Welcome message from the IEEE goSMART chairs. Proceedings - Conference on Local Computer Networks, LCN,
  • Zhdanova AV, Li N, Moessner K. (2008) Semantic web in ubiquitous mobile communications. , pp. 266-287.

Scholarly editions

  • Ayyadurai V, Moessner K, Tafazolli R. (2012) Multipath network coding in wireless mesh networks. , pp. 267-274.

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