Ruben Borralho

Rúben Borralho


Postgraduate Research Student

Academic and research departments

Institute for Communication Systems.

My publications

Publications

Ruben Borralho, Atta Quddus, Abdelrahim Mohamed, Pedro Vieira, Rahim Tafazolli (2021)Cell-Sweeping: A New Paradigm for Cells Deployment in Radio Access Networks

Good network coverage is an important element of Quality of Service (QoS) provision that mobile cellular operators aim to provide. The established requirements for the existing Fifth Generation (5G) and the emerging scenarios for upcoming Sixth Generation (6G) cellular communication technologies highly depend on the coverage quality that the network is able to provide. In addition, some proposed 5G solutions such as densification, are complex, costly, and tend to degrade network coverage due to increased interference which is critical for the cell-edge performance. In this direction, we present a novel concept of cell-sweeping for coverage enhancement in cellular networks. One of the main objectives behind this mechanism relies on overcoming the cell-edge problem which directly translates into better network coverage. In sequence, the concept operation is introduced and compared to the conventional static cell scenarios. These comparisons target mostly the benefits at the cell-edge locations. Additionally, the use of schedulers that take advantage of the sweeping system is expected to extend the cell-edge benefits to the entire network. This is observed when deploying cellsweeping with the Proportional Fair (PF) scheduler. A 5thpercentile improvement of 125% and an average throughput increase of 35% were obtained through system level simulations. The preliminary results presented in this paper suggest that cellsweeping can be adopted as an emerging technology for future Radio Access Network (RAN) deployments.

Ruben Borralho, Abdelrahim Mohamed, Atta Quddus, Pedro Vieira, Rahim Tafazolli (2021)A Survey on Coverage Enhancement in Cellular Networks: Challenges and Solutions for Future Deployments, In: IEEE Communications Surveys and Tutorials IEEE

Seamless and ubiquitous coverage are key factors for future cellular networks. Despite capacity and data rates being the main topics under discussion when envisioning the Fifth Generation (5G) and beyond of mobile communications, network coverage remains one of the major issues since coverage quality highly impacts the system performance and end-user experience. The increasing number of base stations and user terminals is anticipated to negatively impact the network coverage due to increasing interference. Furthermore, the "ubiquitous coverage" use cases, including rural and isolated areas, present a significant challenge for mobile communication technologies. This survey presents an overview of the concept of coverage, highlighting the ways it is studied, measured, and how it impacts the network performance. Additionally, an overlook of the most important key performance indicators influenced by coverage, which may affect the envisioned use cases with respect to throughput, latency, and massive connectivity, are discussed. Moreover, the main existing developments and deployments which are expected to augment the network coverage, in order to meet the requirements of the emerging systems, are presented as well as implementation challenges.

R. Borralho, D. Duarte, A. Quddus, P. Vieira (2020)Developing a LTE Localization Framework using Real Network Data towards RAN Optimization through Context Knowledge, In: Proceedings of The 23rd International Symposium on Wireless Personal Multimedia Communications (WPMC2020) Institute of Electrical and Electronics Engineers (IEEE)

The exponential growth of the network elements and data traffic exchange in the last few years elevated the need of network providers for optimized and cost-efficient solutions regarding network management and monitorization. Solutions such as drive-tests (DTs) are becoming extremely expensive with the vast extension and complexity of nowadays mobile networks. Therefore, this paper provides a solution for optimized networkcontext knowledge acquisition, towards the self-organizing networks (SONs) concept. The presented framework incorporates an entire scheme for network Traces processing and positioning, based on network measurements and fingerprinting techniques. This framework enables a series of different use cases for network management and optimization, with real-time data processing capabilities within the network Traces collection interval (15 minutes), and achieving a median positioning error of 90 m.