Analytical Modeling Of Wireless Communication Systems

Wireless networks represent an inexpensive and convenient way to connect to the Internet. However, despite their applications across several technologies, one challenge still remains: to understand the behavior of wireless sensor networks and assess their performance in large-scale scenarios. When a large number of network nodes need to interact, developing suitable analytical models is essential to ensure the appropriate coverage and throughput of these networks and to enhance user mobility. This is intrinsically difficult due to the size and number of different network nodes and users. This book highlights some examples which show how this problem can be overcome with the use of different techniques. An intensive parameter analysis shows the reader how to the exploit analytical models for an effective development and management of different types of wireless networks.

Wireless networks represent an inexpensive and convenient way to connect to the Internet. However, despite their applications across several technologies, one challenge still remains: to understand the behavior of wireless sensor networks and assess their performance in large-scale scenarios. When a large number of network nodes need to interact, developing suitable analytical models is essential to ensure the appropriate coverage and throughput of these networks and to enhance user mobility. This is intrinsically difficult due to the size and number of different network nodes and users. This book highlights some examples which show how this problem can be overcome with the use of different techniques. An intensive parameter analysis shows the reader how to the exploit analytical models for an effective development and management of different types of wireless networks.

This book focuses on practical computational electrodynamics, guiding the reader step-by-step through the modeling process from the initial "what question must the model answer?", through the setting up of a computer model, to post processing, validation and optimization. The book offers a realistic view of the capabilities and limits of current 3-D field simulators and how to apply this knowledge efficiently to EM analysis and design of RF applications in modern communication systems.

This book addresses the fundamental design and technical challenges for fifth generation (5G) wireless channel models, including multi-frequency bands and multi-scenarios. The book presents a strong vision for 5G wireless communication networks based on current market trends, proven technologies, and future directions. The book helps enable researchers and industry professionals to come up with novel ideas in the area of wireless heterogeneity, to minimize traffic accidents, to improve traffic efficiency, and to foster the development of new applications such as mobile infotainment. The book acts as a comprehensive reference for students, instructors, researchers, engineers, and other professionals, building their understanding of 5G and in designing 5G systems. Addresses fundamental design and technical challenges for 5G wireless channel models; Presents how to create reliable statistical channel models to capture the propagation properties between transmitters and receivers; Pertinent to researchers, engineers, and professionals in 5G.

"This self-contained introduction shows how stochastic geometry techniques can be used for studying the behaviour of heterogeneous cellular networks (HCNs). The unified treatment of analytic results and approaches, collected for the first time in a single volume, includes the mathematical tools and techniques used to derive them. A single canonical problem formulation encompassing the analytic derivation of Signal to Interference plus Noise Ratio (SINR) distribution in the most widely-used deployment scenarios is presented, together with applications to systems based on the 3GPP-LTE standard, and with implications of these analyses on the design of HCNs. An outline of the different releases of the LTE standard and the features relevant to HCNs is also provided. A valuable reference for industry practitioners looking to improve the speed and efficiency of their network design and optimization workflow, and for graduate students and researchers seeking tractable analytical results for performance metrics in wireless HCNs"--

Advances in wireless communications and networking technology have taken us towards a pervasively connected world in which a vast array of wireless devices, from mobile phones to environmental sensors, seamlessly communicate with each other. In many of these systems the freshness of the transmitted information is of high importance. Characterization of time-critical information can be achieved through the so-called real-time status updates that are messages, encapsulated in packets, carrying the timestamp of their generation. Status updates track time-varying content that needs to be transmitted from the generation point to a remote destination in a network. To quantify the freshness of information in networked systems, a novel metric, different from delay or latency, termed as “age of information” (AoI) has been introduced. In this thesis, we focus on characterizing and controlling age under various communication system setups. The first part of the thesis considers multiple access communication systems and comprises two papers. The first paper, investigates AoI in relation with throughput in a shared access setup with heterogeneous traffic. More specifically, we consider a shared access system consisting of a primary link and a network of secondary nodes, with multipacket reception (MPR) capabilities. To study the joint throughput-timeliness performance, we formulate two optimization problems considering both objectives and provide guidelines for the design of such a multiple access system satisfying both timeliness and throughput requirements. In the second paper, we study the AoI performance in various multiple access schemes, including scheduling and random access. We present an analysis of the AoI with and without packet management at the transmission queue of the source nodes, considering that packet management is the capability to replace unserved packets in the queue whenever newer ones arrive. We incorporate the effect of channel fading and network path diversity in such a system and provide simulation results that illustrate the impact of network operating parameters on the performance of the considered access protocols. The second part of the thesis considers the characterization of AoI and other freshness performance metrics in a point-to-point communication link, again comprising two papers. In the third paper of this thesis, we expand the concept of information ageing by introducing the cost of update delay (CoUD) metric to characterize the cost of having stale information at the destination. Furthermore, we introduce the value of information of update (VoIU) metric that captures the degree of importance of the update received at the destination. We employ queue-theoretic concepts and provide a theoretical analysis and insights into the prospects of cost and value. Finally, in the last paper, we study the properties of a sample path of the AoI process, and we obtain a general formula of its stationary distribution. We relate this result to a discrete time queueing system and provide a general expression of the generating function of AoI in relation with the system time, and the peak age of information (PAoI). To illustrate the applicability of the results, we analyze the AoI in single-server queues with different disciplines and assumptions. We build upon these results to provide a methodology for analyzing general non-linear age functions for this type of systems.

With the rapidly increasing penetration of laptop computers and mobile phones, which are primarily used by mobile users to access Internet s- vices like e-mail and World Wide Web (WWW) access, support of Internet services in a mobile environment is an emerging requirement. Wireless n- works have been used for communication among fully distributed users in a multimedia environment that has the needs to provide real-time bursty traffic (such as voice or video) and data traffic with excellent reliability and service quality. To satisfy the huge wireless multimedia service demand and improve the system performance, efficient channel access methods and analytical methods must be provided. In this way very accurate models, that faithfully reproduce the stochastic behavior of multimedia wireless communication and computer networks, can be constructed. Most of these system models are discrete-time queueing systems. Queueing networks and Markov chains are commonly used for the p- formance and reliability evaluation of computer, communication, and m- ufacturing systems. Although there are quite a few books on the individual topics of queueing networks and Markov chains, we have found none that covers the topics of discrete-time and continuous-time multichannel mul- traffic queueing networks. On the other hand, the design and development of multichannel mul- hop network systems and interconnected network systems or integrated n- works of multimedia traffic require not only such average performance m- sures as the throughput or packet delay but also higher moments of traffic departures and transmission delay.

This Springer Brief investigates the voice and elastic/interactive data service support over cognitive radio networks (CRNs), in terms of their delay requirements. The increased demand for wireless communication conflicts with the scarcity of the radio spectrum, but CRNS allow for more efficient use of the networks. The authors review packet level delay requirements of the voice service and session level delay requirements of the elastic/interactive data services, particularly constant-rate and on-off voice traffic capacities in CRNs with centralized and distributed network coordination. Some generic channel access schemes are considered as the coordination mechanism, and call admission control algorithms are developed for non-fully-connected CRNs. Other key topics include the advantages of supporting voice traffic flows with different delay requirements, the mean response time of the elastic data traffic over a centralized CRN, and effects of the traffic load at the base station and file length (service time requirement) distribution on the mean response time. The brief is designed for professionals and researchers working with wireless networks, cognitive radio, and communications. It is also a helpful reference for advanced-level students interested in efficient wireless communications.