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The existence of selfish nodes, who do not cooperate in routing and forwarding, menaces the applicability of mobile ad hoc networks (MANETs). In this paper, we propose a novel price-based method for stimulating cooperation among the nodes of a MANET. This method utilizes the game-theoretic notion of core to distribute the earnings of a cooperation coalition among its members in an optimal manner. In this way, a stable costefficient route is established between communicating parties. [ABSTRACT FROM AUTHOR]

Wireless Sensor Networks (WSNs) are spreading around in multiple fields of applications because they perform measuring tasks in a flexible way. This paper presents a survey on nowadays research efforts on the application of these WSNs to the automobile industry, to agriculture, and to wearable technologies (healthcare and athletes monitoring). From our practical deployments, it is important to highlight the functionalities for the automotive industry, and the results extracted from our application to a vineyard. Research on wearable technologies constitutes a challenge, and wireless healthcare solutions in the context of fabrics are being addressed. [ABSTRACT FROM AUTHOR]

The article presents information on wireless communications. The field of mobile wireless communications is currently one of the fastest growing segments of the telecommunications industry. Wireless devices have nowadays found extensive use and have become an indispensable tool on the everyday life of many people. both the professionally and personally. To gain insight into the momentum of the growth of the wireless industry, it is sufficient to state the tremendous growth in the number of worldwide subscribers of wireless systems. This figure has risen from only one mobile subscriber per 100 inhabitants worldwide in 1990 to 26 subscribers per 100 inhabitants in 1999 and the growth continues. This increasing number of subscribers is obviously reflected in monetary terms as well.

Discusses wireless data networks. Concept of internetworking; Functions of the Open System Interconnection (OSI) reference model; Purposes of each layers of the OSI model.

Focuses on the history of wireless technologies. Concept of the operational wireless telegraph apparatus developed by Guglielmo Marconi; Timeline on the evolution of wireless technologies; Functions of packet radio.

Chapter 13 focuses on the transport layer in micro-cell and macro-cell wireless networks. The task in the transport layer is to organize the speed of transmission, acknowledgement and possible retransmission of every packet of a data transfer. It deals primarily with network congestion and reduced bandwidth problems. [ABSTRACT FROM PUBLISHER]

Can a silicon-based technology like Si/SiGe HBT exhibit performance compatible with the demands of the low-power wireless communications marketplace, and does it retain the low cost and manufacturability of its silicon pedigree? This chapter will attempt to answer that question by summarizing the progress and prospects for this technology in the area of low-power mobile communications systems, with particular emphasis on circuit and device performance. It is organized in the following manner. Section 4.2 outlines the advantages and disadvantages of silicon technology for applications to high-frequency low-power communications circuits. Section 4.3 summarizes the key device design aspects of SiGe devices, particularly with respect to high-frequency applications. Section 4.4 provides an assessment of passive component technology in Si/SiGe technology. Section 4.5 provides a direct comparison of the performance of silicon-based HBTs to those based on III-V technologies. Finally, Section 4.6 provides an overview of reported circuit performance in Si/SiGe HBT technology, with emphasis on low-power communications applications. [ABSTRACT FROM PUBLISHER]

This chapter describes a series of novel concepts to increase microwave power amplifier efficiency. Within modern wireless systems, power amplifiers must meet exacting linearity specifica-tions, which tend to be at odds with the need for high efficiency. To characterize these specifications and associated trade-offs, the authors first review the linearity requirements and dynamic range requirements of representative high performance communication systems. They then demonstrate concepts for power amplifier improvement that can meet the system requirements. [ABSTRACT FROM PUBLISHER]

This chapter focuses on communications subsystem performance enhancements potentially attainable via use of vibrating micromechanical resonator circuits in MEMS-based transceiver architectures. Section 12.2 begins by reviewing the issues involved with transceiver miniaturization, specifically focusing on the need for high Q. Section 12.3 follows with an overview of various micromechanical signal processing circuits, describing micromechanical tanks, filters, mixer-filters, and switches and providing sufficient detail to facilitate the incorporation of such circuits into communications subsystems. Specific transceiver architectures using such devices are then presented in Sections 12.4 and 12.5, with a focus on the specific performance enhancements afforded by each approach. Section 12.6 then serves as a reminder that this is still a fledgling technology, emphasizing the present limitations of this technology and giving a sprinkling of the specific research problems that must be solved before the architectures of Sections 12.4 and 12.5 can become a reality. Sections 12.7 and 12.7.4.1 finally close the chapter with details on techniques for combining mechanical and transistor circuits onto single chips. [ABSTRACT FROM PUBLISHER]

Following a brief overview of the basic constructing elements for modern planar microwave/millimeter-wave passive circuits, this chapter presents two innovative approaches to meet the above-mentioned technical challenges of high-Q passive components for high-frequency applications. The first approach, based on a unique process named SIMPOL (silicon/metal/polyimide), aims at realizing low-loss, high-isolation interconnects and passive components on low-resistivity, CMOS-grade silicon substrates. The second approach for high-Q passive components is based on the photonic bandgap (PBG) concept. These are basically periodic structures that can be used to control the propagation, reflection, or radiation of electromagnetic waves in a slightly different way compared to conventional waveguiding or filtering techniques. [ABSTRACT FROM PUBLISHER]

The airlink subsystem is defined as the span between the user host's connection point and the subscriber unit. It includes the service provider's message switch/area controller, base stations, and the radio modem. There are at least four current philosophical control approaches: (1) decentralized, (2) partially decentralized, (3) partially centralized, and (4) centralized. Each of these approaches is examined in order, from highly decentralized to highly centralized. [ABSTRACT FROM PUBLISHER]

The variety of public network choices cited in the preceding chapter leads some potential users to despair at what seems a plethora of alternatives. Actually, specific user requirements can quickly eliminate many network candidates. This permits a more straightforward assessment of realistic alternatives. A few of those salient user characteristics are discussed in this chapter. [ABSTRACT FROM PUBLISHER]

Packet systems are the least uniform and most complex. Examples of the enormous range of products are presented in this chapter, in increasing degrees of complexity, beginning with the client modem and working through servers and gateways to the host application. [ABSTRACT FROM PUBLISHER]