Recent Advances in Cellular D2D Communications

Device-to-device (D2D) communications have attracted a great deal of attention from researchers in recent years. It is a promising technique for offloading local traffic from cellular base stations by allowing local devices, in physical proximity, to communicate directly with each other. Furthermore, through relaying, D2D is also a promising approach to enhancing service coverage at cell edges or in black spots. However, there are many challenges to realizing the full benefits of D2D. For one, minimizing the interference between legacy cellular and D2D users operating in underlay mode is still an active research issue. With the 5th generation (5G) communication systems expected to be the main data carrier for the Internet-of-Things (IoT) paradigm, the potential role of D2D and its scalability to support massive IoT devices and their machine-centric (as opposed to human-centric) communications need to be investigated. New challenges have also arisen from new enabling technologies for D2D communications, such as non-orthogonal multiple access (NOMA) and blockchain technologies, which call for new solutions to be proposed. This edited book presents a collection of ten chapters, including one review and nine original research works on addressing many of the aforementioned challenges and beyond

Recent advances in radio resource management for heterogeneous LTE/LTE-A networks

As heterogeneous networks (HetNets) emerge as one of the most promising developments toward realizing the target specifications of Long Term Evolution (LTE) and LTE-Advanced (LTE-A) networks, radio resource management (RRM) research for such networks has, in recent times, been intensively pursued. Clearly, recent research mainly concentrates on the aspect of interference mitigation. Other RRM aspects, such as radio resource utilization, fairness, complexity, and QoS, have not been given much attention. In this paper, we aim to provide an overview of the key challenges arising from HetNets and highlight their importance. Subsequently, we present a comprehensive survey of the RRM schemes that have been studied in recent years for LTE/LTE-A HetNets, with a particular focus on those for femtocells and relay nodes. Furthermore, we classify these RRM schemes according to their underlying approaches. In addition, these RRM schemes are qualitatively analyzed and compared to each other. We also identify a number of potential research directions for future RRM development. Finally, we discuss the lack of current RRM research and the importance of multi-objective RRM studies

Inband Relaying in Long Term Evolution-Advanced Networks

The set of stringent requirements for 4G radio access networks has triggered the embodiment of new small low-power nodes, e.g. relay, Femto and Pico access nodes, as part of the network infrastructure. Various types of relay nodes are currently supported in IEEE 802.16m and 3GPP LTE-Advanced, e.g. inband Layer 2 or Layer 3 nodes and outband nodes, considering different functional capabilities and backhauling characteristics. In general, relay nodes are characterized by compact physical characteristics, low power consumption, a wireless backhaul link to the core network, and relaxed installation guidelines with respect to radiation and planning regulation. In specific, inband relay nodes, the matter of this study, are Layer 3 access nodes with time-multiplexed transmission and reception on their wireless backhaul and access links, which operate on the same frequency band. These characteristics impose serious challenges on one hand, but allow for significant improvements on the other hand. In this context, the deployment flexibility of relay nodes simplifies the network planning procedure and reduces deployment costs. On the other hand, low power transmission and limited antenna capabilities result in small relay cell coverage areas which will lead to load imbalances. Besides, multiplexing backhaul and access communications on different subframes implies the need for suitable two-hop resource allocation and scheduling. Further challenges are attributed to increased interference levels compared to macrocell deployments, as well as the introduction of a new interference type known as relay-to-relay interference resulting from the misalignment of access and backhaul link dedicated subframes at different relay nodes. The research towards this thesis has addressed these challenges within 3GPP LTE-Advanced context. A feasibility study of different relaying modes is provided and the performance of relay deployments is evaluated in different propagation environments. Thereafter, simple network planning techniques are proposed to alleviate the limitations of the inband backhaul link. Further, novel techniques are investigated to address resource allocation and scheduling, load balancing and interference coordination. The performance of proposed techniques along with the energy efficiency of relay nodes is evaluated. Results show in general significant gains and validate relaying as an efficient enhancement technology

Opportunistic device-to-device communication in cellular networks: from theory to practice

Mención Internacional en el título de doctorCellular service providers have been struggling with users’ demand since the emergence of mobile Internet. As a result, each generation of cellular network prevailed over its predecessors mainly in terms of connection speed. However, the fifth generation (5G) of cellular network promises to go beyond this trend by revolutionizing the network architecture. Device-to-Device (D2D) communication is one of the revolutionary changes that enables mobile users to communicate directly without traversing a base station. This feature is being actively studied in 3GPP with special focus on public safety as it allows mobiles to operate in adhoc mode. Although under the (partial) control of the network, D2D communications open the door to many other use-cases. This dissertation studies different aspects of D2D communications and its impact on the key performance indicators of the network. We design an architecture for the collaboration of cellular users by means of timely exploited D2D opportunities. We begin by presenting the analytical study on opportunistic outband D2D communications. The study reveals the great potential of opportunistic outband D2D communications for enhancing energy efficiency, fairness, and capacity of cellular networks when groups of D2D users can be form and managed in the cellular network. Then we introduce a protocol that is compatible with the latest release of IEEE and 3GPP standards and allows for implementation of our proposal in a today’s cellular network. To validate our analytical findings, we use our experimental Software Defined Radio (SDR)-based testbed to further study our proposal in a real world scenario. The experimental results confirm the outstanding potential of opportunistic outband D2D communications. Finally, we investigate the performance merits and disadvantages of different D2D “modes”. Our investigation reveals, despite the common belief, that all D2D modes are complementary and their merits are scenario based.This work has been supported by IMDEA Networks Institute.Programa Oficial de Doctorado en Ingeniería TelemáticaPresidente: Douglas Leith.- Secretario: Albert Banchs Roca.- Vocal: Carla Fabiana Chiasserin

D3.2 First performance results for multi -node/multi -antenna transmission technologies

This deliverable describes the current results of the multi-node/multi-antenna technologies investigated within METIS and analyses the interactions within and outside Work Package 3. Furthermore, it identifies the most promising technologies based on the current state of obtained results. This document provides a brief overview of the results in its first part. The second part, namely the Appendix, further details the results, describes the simulation alignment efforts conducted in the Work Package and the interaction of the Test Cases. The results described here show that the investigations conducted in Work Package 3 are maturing resulting in valuable innovative solutions for future 5G systems.Fantini. R.; Santos, A.; De Carvalho, E.; Rajatheva, N.; Popovski, P.; Baracca, P.; Aziz, D.... (2014). D3.2 First performance results for multi -node/multi -antenna transmission technologies. http://hdl.handle.net/10251/7675

Wireless Patient Monitoring over 4G Network

The purpose of this thesis is to explain how remote patient monitoring systems work over the 4G network using wearable sensors and corresponding interface devices. Gathered data from the sensing devices are carried over the Monitoring Wireless Sensor Network to the more elaborate 4G Network where the data is then relayed to the interface devices for reading, storage, interpretation and effective utilization. This thesis describes the underlying technologies and principles of sensors and sensor net-works, the concept of the 4G Network and how it integrates with the sensor network. The goal of Wireless Patient Monitoring over the 4G Network is link the spatial gap that exist between Healthcare and ICT, this will in turn enhance patients care efficiency while cutting costs, maximising profits and increase security while monitoring patients. This thesis is important in that it gives the reader an overview and basic idea of how a wireless patient monitoring system works over the 4G Network. An increasing number of ICT firms, healthcare and medical institutions are investing heavily on remote patient monitoring systems technologies and this thesis provides the reader the insight of how such systems work and how they can be implemented