Directional antenna technologies have made significant advancements in the last decade. These advances have opened the door to many exciting new design opportunities for wireless networks to enhance quality of service (QoS), performance, and network capacity. In this book, experts from around the world present the latest research and development in

In this dissertation, we focus on designing several cross-layer optimizations to boost the performance of wireless networks. We categorize our efforts into two directions: (a) improvement of spatial reusability and multi-hop performance via Directional Antennas, and (b) analysis and optimization of the IEEE 802.11 multi-rate networks. Since existing protocols are incapable of fully exploiting the benefits of a directional antenna system, we propose a, broadcast and routing protocol for such systems. All our proposals assume cross layer interaction between the Network, MAC and PHY layers. Next, we analyze multi-rate networks in the context of IEEE 802.11 DCF networks and propose an analytical model to study the link-delay characteristics of such systems. We then propose an online algorithm Time Fair CSMA (TFCSMA), for guaranteeing air-time fairness and thereby mitigating the recently observed rate anomaly problem of IEEE DCF multi-rate networks. Following the design of TFCSMA, we concentrate on the problem of rate adaptation for time-varying wireless channels. We thoroughly investigate the impact of transmission rate on the performance of a wireless link. We then propose Stochastic Automata Rate Adaptation Algorithm (SARA). SARA is inspired by Stochastic Learning Automata (SLA), a machine learning technique for adaptation in random environments. As opposed to the previous work in this area, SARA is ideally suited for both stationary and non-stationary channel environments and is completely compatible with the existing IEEE 802.11 MAC standard.

Spectrum Sharing in Wireless Networks: Fairness, Efficiency, and Security provides a broad overview of wireless network spectrum sharing in seven distinct sections: The first section examines the big picture and basic principles, explaining the concepts of spectrum sharing, hardware/software function requirements for efficient sharing, and future trends of sharing strategies. The second section contains more than 10 chapters that discuss differing approaches to efficient spectrum sharing. The authors introduce a new coexistence and sharing scheme for multi-hop networks, describe the space-time sharing concept, introduce LTE-U, and examine sharing in broadcast and unicast environments. They then talk about different cooperation strategies to achieve mutual benefits for primary users (PU) and secondary users (SU), discuss protocols in a spectrum sharing context, and provide different game theory models between PUs and SUs. The third section explains how to model the interactions of PUs and SUs, using an efficient calculation method to determine spectrum availability. Additionally, this section explains how to use scheduling models to achieve efficient SU traffic delivery. The subject of the fourth section is MIMO-oriented design. It focuses on how directional antennas and MIMO antennas greatly enhance wireless network performance. The authors include a few chapters on capacity/rate calculations as well as beamforming issues under MIMO antennas. Power control is covered in the fifth section which also describes the interference-aware power allocation schemes among cognitive radio users and the power control schemes in cognitive radios. The sixth section provides a comprehensive look at security issues, including different types of spectrum sharing attacks and threats as well as corresponding countermeasure schemes. The seventh and final section covers issues pertaining to military applications and examines how the military task protects its data flows when sharing the spectrum with civilian applications.

A large portion of the network capacity of an ad hoc network can be wasted by the medium access mechanisms of omni-directional antennas. To overcome this problem, researchers propose the use of directional or adaptive antennas that largely reduce radio interference, improving the utilization of wireless medium and the resulting network throughput.

The book introduces the basic foundations of high mathematics and vector algebra. Then, it explains the basic aspects of classical electrodynamics and electromagnetism. Based on such knowledge readers investigate various radio propagation problems related to guiding structures connecting electronic devices with antenna terminals placed at the different radar systems. It explains the role of antennas in process of transmission of radio signals between the terminals. Finally, it shows the relation between the main operational charactistics of each kind of radar and the corresponding knowledge obtained from the previous chapters.

This book fills a gap in the existing literature by combining a plethora of WSN-based emerging technologies into a single source so that reviewers can form opinions regarding these technologies. It presents different types of emerging communication technologies based on WSNs and describes how wireless sensor networks can be integrated with other communication technologies. It covers many of the new techniques and demonstrates the application of WSNs. The book is composed of 14 chapters, divided into four parts.

Session Initiation Protocol (SIP), standardized by the Internet Engineering Task Force (IETF), has emulated the simplicity of the protocol architecture of hypertext transfer protocol (HTTP) and is being popularized for VoIP over the Internet because of the ease with which it can be meshed with web services. However, it is difficult to know exactly how many requests for comments (RFCs) have been published over the last two decades in regards to SIP or how those RFCs are interrelated. Handbook on Session Initiation Protocol: Networked Multimedia Communications for IP Telephony solves that problem. It is the first book to put together all SIP-related RFCs, with their mandatory and optional texts, in a chronological and systematic way so that it can be used as a single super-SIP RFC with an almost one-to-one integrity from beginning to end, allowing you to see the big picture of SIP for the basic SIP functionalities. It is a book that network designers, software developers, product manufacturers, implementers, interoperability testers, professionals, professors, and researchers will find to be very useful. The text of each RFC from the IETF has been reviewed by all members of a given working group made up of world-renowned experts, and a rough consensus made on which parts of the drafts need to be mandatory and optional, including whether an RFC needs to be Standards Track, Informational, or Experimental. Texts, ABNF syntaxes, figures, tables, and references are included in their original form. All RFCs, along with their authors, are provided as references. The book is organized into twenty chapters based on the major functionalities, features, and capabilities of SIP.