Design and Analysis of Medium Access Control Protocols for Broadband Wireless Networks

The next-generation wireless networks are expected to integrate diverse network architectures and various wireless access technologies to provide a robust solution for ubiquitous broadband wireless access, such as wireless local area networks (WLANs), Ultra-Wideband (UWB), and millimeter-wave (mmWave) based wireless personal area networks (WPANs), etc. To enhance the spectral efficiency and link reliability, smart antenna systems have been proposed as a promising candidate for future broadband access networks. To effectively exploit the increased capabilities of the emerging wireless networks, the different network characteristics and the underlying physical layer features need to be considered in the medium access control (MAC) design, which plays a critical role in providing efficient and fair resource sharing among multiple users. In this thesis, we comprehensively investigate the MAC design in both single- and multi-hop broadband wireless networks, with and without infrastructure support. We first develop mathematical models to identify the performance bottlenecks and constraints in the design and operation of existing MAC. We then use a cross-layer approach to mitigate the identified bottleneck problems. Finally, by evaluating the performance of the proposed protocols with analytical models and extensive simulations, we determine the optimal protocol parameters to maximize the network performance. In specific, a generic analytical framework is developed for capacity study of an IEEE 802.11 WLAN in support of non-persistent asymmetric traffic flows. The analysis can be applied for effective admission control to guarantee the quality of service (QoS) performance of multimedia applications. As the access point (AP) becomes the bottleneck in an infrastructure based WLAN, we explore the multiple-input multiple-output (MIMO) capability in the future IEEE 802.11n WLANs and propose a MIMO-aware multi-user (MU) MAC. By exploiting the multi-user degree of freedom in a MIMO system to allow the AP to communicate with multiple users in the downlink simultaneously, the proposed MU MAC can minimize the AP-bottleneck effect and significantly improve the network capacity. Other enhanced MAC mechanisms, e.g., frame aggregation and bidirectional transmissions, are also studied. Furthermore, different from a narrowband system where simultaneous transmissions by nearby neighbors collide with each other, wideband system can support multiple concurrent transmissions if the multi-user interference can be properly managed. Taking advantage of the salient features of UWB and mmWave communications, we propose an exclusive region (ER) based MAC protocol to exploit the spatial multiplexing gain of centralized UWB and mmWave based wireless networks. Moreover, instead of studying the asymptotic capacity bounds of arbitrary networks which may be too loose to be useful in realistic networks, we derive the expected capacity or transport capacity of UWB and mmWave based networks with random topology. The analysis reveals the main factors affecting the network (transport) capacity, and how to determine the best protocol parameters to maximize the network capacity. In addition, due to limited transmission range, multi-hop relay is necessary to extend the communication coverage of UWB networks. A simple, scalable, and distributed UWB MAC protocol is crucial for efficiently utilizing the large bandwidth of UWB channels and enabling numerous new applications cost-effectively. To address this issue, we further design a distributed asynchronous ER based MAC for multi-hop UWB networks and derive the optimal ER size towards the maximum network throughput. The proposed MAC can significantly improve both network throughput and fairness performance, while the throughput and fairness are usually treated as a tradeoff in other MAC protocols

Radio Communications

In the last decades the restless evolution of information and communication technologies (ICT) brought to a deep transformation of our habits. The growth of the Internet and the advances in hardware and software implementations modified our way to communicate and to share information. In this book, an overview of the major issues faced today by researchers in the field of radio communications is given through 35 high quality chapters written by specialists working in universities and research centers all over the world. Various aspects will be deeply discussed: channel modeling, beamforming, multiple antennas, cooperative networks, opportunistic scheduling, advanced admission control, handover management, systems performance assessment, routing issues in mobility conditions, localization, web security. Advanced techniques for the radio resource management will be discussed both in single and multiple radio technologies; either in infrastructure, mesh or ad hoc networks

A Prospective Look: Key Enabling Technologies, Applications and Open Research Topics in 6G Networks

The fifth generation (5G) mobile networks are envisaged to enable a plethora of breakthrough advancements in wireless technologies, providing support of a diverse set of services over a single platform. While the deployment of 5G systems is scaling up globally, it is time to look ahead for beyond 5G systems. This is driven by the emerging societal trends, calling for fully automated systems and intelligent services supported by extended reality and haptics communications. To accommodate the stringent requirements of their prospective applications, which are data-driven and defined by extremely low-latency, ultra-reliable, fast and seamless wireless connectivity, research initiatives are currently focusing on a progressive roadmap towards the sixth generation (6G) networks. In this article, we shed light on some of the major enabling technologies for 6G, which are expected to revolutionize the fundamental architectures of cellular networks and provide multiple homogeneous artificial intelligence-empowered services, including distributed communications, control, computing, sensing, and energy, from its core to its end nodes. Particularly, this paper aims to answer several 6G framework related questions: What are the driving forces for the development of 6G? How will the enabling technologies of 6G differ from those in 5G? What kind of applications and interactions will they support which would not be supported by 5G? We address these questions by presenting a profound study of the 6G vision and outlining five of its disruptive technologies, i.e., terahertz communications, programmable metasurfaces, drone-based communications, backscatter communications and tactile internet, as well as their potential applications. Then, by leveraging the state-of-the-art literature surveyed for each technology, we discuss their requirements, key challenges, and open research problems

JTIT

kwartalni

A prospective look: key enabling technologies, applications and open research topics in 6G networks

The fifth generation (5G) mobile networks are envisaged to enable a plethora of breakthrough advancements in wireless technologies, providing support of a diverse set of services over a single platform. While the deployment of 5G systems is scaling up globally, it is time to look ahead for beyond 5G systems. This is mainly driven by the emerging societal trends, calling for fully automated systems and intelligent services supported by extended reality and haptics communications. To accommodate the stringent requirements of their prospective applications, which are data-driven and defined by extremely low-latency, ultra-reliable, fast and seamless wireless connectivity, research initiatives are currently focusing on a progressive roadmap towards the sixth generation (6G) networks, which are expected to bring transformative changes to this premise. In this article, we shed light on some of the major enabling technologies for 6G, which are expected to revolutionize the fundamental architectures of cellular networks and provide multiple homogeneous artificial intelligence-empowered services, including distributed communications, control, computing, sensing, and energy, from its core to its end nodes. In particular, the present paper aims to answer several 6G framework related questions: What are the driving forces for the development of 6G? How will the enabling technologies of 6G differ from those in 5G? What kind of applications and interactions will they support which would not be supported by 5G? We address these questions by presenting a comprehensive study of the 6G vision and outlining seven of its disruptive technologies, i.e., mmWave communications, terahertz communications, optical wireless communications, programmable metasurfaces, drone-based communications, backscatter communications and tactile internet, as well as their potential applications. Then, by leveraging the state-of-the-art literature surveyed for each technology, we discuss the associated requirements, key challenges, and open research problems. These discussions are thereafter used to open up the horizon for future research directions

High speed 802.11ad wireless video streaming

The aim of this thesis is to investigate, both theoretically and experimentally, the capability of the IEEE 802.11ad device, the Wireless Gigabit Alliance known as WiGig operating in the 60 GHz band to handle rise in data traffic ubiquitous to high speed data transmission such as bulk data transfer, and wireless video streaming. According to Cisco and others, it is estimated that in 2020, internet video traffic will account for 82 % of all consumer internet traffic. This research evalu- ated the feasibility of the 60 GHz to provide minimum data rate of about 970 Mbps from the Ethernet link limited or clamped to 1 Gbps. This translated to 97 % effi- ciency with respect to the IEEE 802.11ad system performance. For the first time, the author proposed the enhancement of millimetre wave propagation through the use of specular reflection in non-line-of-sight environment, providing at least 94 % bandwidth utilization. Additional investigations result of the IEEE 802.11ad device in real live streaming of 4k ultra-high definition (UHD) video shows the feasibility of aggressive frequency reuse in the absence of co-channel interference. Moreover, using heuristic approach, this work compared materials absorption and signal reception at 60 GHz and the results gives better performance in contrast to the theoretical values. Finally, this thesis proposes a framework for the 802.11ad wireless H.264 video streaming over 60 GHz band. The work describes the potential and efficiency of WiGig device in streaming high definition (HD) video with high temporal index (TI) and 4k UHD video with no retransmission. Caching point established at the re-transmitter increase coverage and cache multimedia data. The results in this thesis shows the growing potential of millimeter wave technology, the WiGig for very high speed bulk data transfer, and live streaming video transmission

Wireless Network Communications Overview for Space Mission Operations

The mission of the On-Board Wireless Working Group (WWG) is to serve as a general CCSDS focus group for intra-vehicle wireless technologies. The WWG investigates and makes recommendations pursuant to standardization of applicable wireless network protocols, ensuring the interoperability of independently developed wireless communication assets. This document presents technical background information concerning uses and applicability of wireless networking technologies for space missions. Agency-relevant driving scenarios, for which wireless network communications will provide a significant return-on-investment benefiting the participating international agencies, are used to focus the scope of the enclosed technical information

Routage et gestion de la mobilité dans les réseaux personnels

L'objectif de cette thèse est d'étudier des méthodes et des stratégies efficaces pour le routage et la gestion de la mobilité dans le cadre des réseaux personnels. Dans un premier temps, nous proposons le cadre de nos études: Personal Ubiquitous Environments (PUE). Un PUE est constitué d'un ensemble d'utilisateurs ayant des terminaux disposant d'interfaces réseau hétérogènes, et dont l'objectif est de mettre en oeuvre des mécanismes de coopération et de partage des ressources de manière totalement distribuée. Dans ce cadre, la thèse a proposé des solutions innovantes contribuant à améliorer la communication inter et intra réseau personnels. La première contribution porte sur le protocole PNRP (Personal Network Routing Protocol) dont le but est de développer un routage à base de politiques (policy-based routing) pour les environnements personnels. La seconde, intitulée ADD (Adaptive Distributed gateway Discovery), est un mécanisme totalement distribué pour la découverte de multiples chemins vers une passerelle vers un réseau opéré. De plus, étant donné que ces environnements sont hétérogènes par leurs compositions (réseaux d'accès, terminaux ...), une architecture de gestion de la mobilité qui permet une gestion unifiée de la localisation et de la mobilité sans coutures appliquant lénsemble des noeuds a également été traitée. Les résultats d'évaluation par simulation démontrent l'applicabilité et léfficacité des ces protocoles.The aim of this thesis is to investigate methods and strategies for efficient routing and mobility management in personal environments. The concept of Personal Ubiquitous Environments (PUE) is introduced which accommodates heterogeneous devices and access networks of different users and sustain the notion of sharing resources in a distributed manner. A prerequisite for achieving the resource (devices, networks) sharing in personal environments is the deployment of suitable communication protocols which establish efficient multi-hop routes betweens the devices of the PUE. Personal Network Routing Protocol (PNRP) has been developed to perform policy-based routing in personal environments. Moreover, in certain personal networking scenarios, the infrastructure network components (i.e. gateways) are more than one-hop distance from the user's devices; Adaptive Distributed gateway Discovery (ADD) protocol is thereby proposed to efficiently discover the multi-hop routes towards the gateway in a totally distributed manner. All the more, since the personal environments regroups heterogeneous access networks, an efficient mobility management architecture is proposed which offers unified location management and seamless handover experience to dynamic personal nodes. The proposed protocols are assessed by means of numerous communication scenarios; the simulation results demonstrate the applicability of the proposed protocols