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 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.

HereOCOs a unique new book that focuses on the future direction in wireless/mobile telecommunications as a standalone concept for building wireless IP systems, including commercial, campus, local, and global networks. It examines the integration of the Internet and mobile networks, which are merging as a result of global demand for seamless mobile communication."

A self-contained introduction to the use of stochastic geometry techniques for studying the behaviour of heterogeneous cellular networks.

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.

A new modeling framework is introduced for the analytical study of medium access control (MAC) protocols operating in multihop wireless ad hoc networks, i.e., wireless networks characterized by the lack of any pre-existent infrastructure and where participating devices must cooperatively provide the basic functionalities that are common to any computer network. The proposed modeling framework focuses on the interactions between the physical (PHY) and MAC layers, and on the impact that each node has on the dynamics of every other node in the network. To account for the effects of both cross-layer interactions and the interference among all nodes, a novel linear model is introduced with which topology and PHY/MAC-layer aspects are naturally incorporated in what we define as interference matrices. A key feature of the model is that nodes can be modeled individually, i.e., it allows a per-node setup of many layer-specific parameters. Moreover, no spatial probability distribution or special arrangement of nodes is assumed; the model allows the computation of individual (per-node) performance metrics for any given network topology and radio channel model.