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The purpose of this paper is to provide a general overview of previous and current communications governments and intergovernmental bodies around the world. They have been increasingly reporting incidents where fixed satellite services (FSS) are being disrupted by interference from terrestrial wireless services in the extended and standard C-band frequencies (3.4 to 4.2 GHz). However, comparisons, analysis and conclusions are included into this paper to provide the upcoming researchers with the best extracts. Furthermore, it gives an idea regarding how different countries can have different consequences based on different issues. Finally, realization the impact of forthcoming technology on satellite used under the C-band category have been discussed in the conclusions. [ABSTRACT FROM AUTHOR]

Adaptive middleware and wireless networks are hot topics in many discussions today. Literature describes a lot of approaches which are based upon existing middleware technologies by adding functionalities for adaptive behavior. Disadvantage of this proceeding is the resulting dependence upon the interface provided by the underlying middleware. This paper will describe a whole new approach for adaptive middleware which is on the one hand able to manage and organize a complex mobile wireless network. On the other hand it interprets requirements demanded from mobile services which are running on top of it. These requirements are described within a meta information base which comes along with a mobile service. Using this additional information the middleware adapts its behavior to optimize the performance of the complete network. To understand the behavior of the middleware this paper will first give a short description of the structure of the middleware. Subsequently it will classify four different abstraction layers starting with a view onto the entire network up to the fine-tuning mechanisms within the middleware itself. Afterward it will describe in detail a set the different adaption approaches within the four abstraction layers and show how these approaches are integrated into the middleware. [ABSTRACT FROM AUTHOR]

Wireless mesh networks based on IEEE 802.11 technology are a scalable and efficient solution for next generation wireless networking to provide wide-area wideband internet access to a significant number of users. The deployment of these wireless mesh networks may be within different authorities and without any planning, they are potentially overlapped partially or completely in the same service area. So in this paper is design a new model to Enhancement Throughput of Unplanned Wireless Mesh Networks Deployment Using Partitioning Hierarchical Cluster (PHC) and using bridge nodes to allow interworking traffic between these WMNs to reduce the performance degradation, the unplanned deployment of WMNs are determinates their performance. [ABSTRACT FROM AUTHOR]

In this paper, a novel dynamic contention window control scheme is presented to improve the performance and energy efficiency of IEEE 802.11-based CSMA/CA DCF wireless networks operating in ad-hoc mode. The number of competing nodes in physical carrier sense systems has a major influence on the probability of collisions and a subsequent impact on DCF performance and on the energy consumed. A new cross-layer approach to alleviating this problem is developed, which attempts to improve the performance and energy efficiency by controlling the contention window size in the MAC layer according to the number of competing nodes, and the length of the MPDU (MAC Protocol Data Unit) payload according to the physical channel condition in the PHY layer. [ABSTRACT FROM AUTHOR]

In order to implement a wireless sensor network in process automation system it is needed to specify the sample number for the sensors. Because of the hardware and power supply limitations, wireless sensors are applied to discrete event control system. In wireless sensor network the highest sample number is restricted in comparison to the wired one. Moreover, the lowest sample number is also constrained by the limitations imposed by the control limits values. In this paper, relations between sample number and actuator's frequency drift in discrete domain is formulated and presented. The central and autonomous sensor network structures are introduced. In addition, ways to compromise the sample number with the actuator's frequency and control limits value are acknowledged. An approach to find the optimal sample number is proposed. It is shown when the sensor network becomes larger, autonomous network can partly compensate energy consumption increase by adding the sample number whereas central network does not support this feature. [ABSTRACT FROM AUTHOR]

Spatial query execution is an essential functionality of a sensor network. Redundancy within a sensor network can be exploited to reduce the communication cost incurred in execution of such queries. Any reduction in communication cost would result in an efficient use of battery energy, which is very limited in sensors. One approach to reduce the communication cost of a query is to self-organize the network, in response to a query, into a topology that involves only a small subset of the sensors sufficient to process the query. In this paper, we design an efficient algorithm for the above problem of self-organization of a sensor network into an optimal logical topology, to reduce energy consumption, in response to a query. We introduce the EEDSOSC algorithm, a new Energy Efficient Distributed Selforganization approximation algorithm for Optimal Sensor Cover that produces a near-Optimal Sensor Cover with minimum consumed energy, minimum connected sensor cover and less message communication overhead. The performance of algorithm is tested for both dense and sparse sensor networks. Through extensive simulations, we have shown that our designed technique result in substantial energy savings in a sensor network. Moreover, experiments have been conducted on networks with different sensors transmission radius, different query sizes, and different network configurations. All experimental tests are evaluated using simulations and the experimental results showed that the proposed approach results in a significant communication cost reduction and an energy efficient near-optimal connected sensor cover. Compared with other techniques, the results demonstrated a significant improvement of the proposed technique in terms of energy efficient query cover with lower communication cost. [ABSTRACT FROM AUTHOR]

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]

As wireless networks evolves towards the 3G and 4G architectures the mobile core networks provides a platform for all-IP convergence of mobile and fixed networks allowing for better integration of the Internet and cellular networks, providing better quality of service, charging mechanisms and integration of different services. Due to this convergence, there have been various evidences of interoperability limitations between the mobile and fixed networks such as protocol adaptation, end-to-end Quality of Service (QoS), charging and signalling interworking. Most of these limitations are currently been addressed by respective standards bodies and various proposals are being implemented. In this paper we investigate the signalling limitations across converged networks which are caused by the use of different Session Initiation Protocol (SIP) profiles for signalling in both mobile and fixed networks. We carried out various performance based simulations on the 3GPP proposed solution in which our results reveal critical shortcomings in the solution. We then proposed a new configuration for the system to enable the solution work more efficiently. [ABSTRACT FROM AUTHOR]

The recent boom in wireless communications has led to a wide range of new applications. Wireless positioning is an emerging technology which can provide accurate locations for indoor environments when satellite based positioning systems are not available. In this paper, a Session Initiation Protocol (SIP) based system architecture for wireless positioning is described and an overview of how this can be used in overall system design is provided. New simulation results show that SIP is effective as a network signaling protocol for indoor wireless positioning. [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]

This paper presents a novel network design algorithm for Wireless Local Area Networks (WLANs) considering optimal access point placement and frequency channel assignment problems. The proposed algorithm is a cross-layer approach, accounting the physical layer and the data link layer functionalities of the WLANs in the network design process. Specifically, a multi-objective optimization problem is defined. The proposed objective function separates the physical layer considerations and the data link layer contributions in order to differently change the weights of the two characteristics of WLANs. Numerical results are presented and the jointed impact of the physical and the data link layer functionalities on the WLAN quality of services are evaluated. [ABSTRACT FROM AUTHOR]

The Multi Protocol Label Switching (MPLS) is a technology providing means to ensure quality of service requirements and to control data flows in IP networks. Therefore an increasing number of telecommunication core networks are deploying MPLS. A next step will be the integration of MPLS into the wireless access networks. But MPLS has been developed with respect to wired networks. In this paper, we propose an integration of MPLS and Mobile IP Regional Registration as a mobility solution for wireless access networks together with an approach to support micro-mobility and quality of service. Furthermore, we propose an additional low latency handoff scheme with experimental results. [ABSTRACT FROM AUTHOR]

The article gives information about a chapter of the book "Telecommunications Optimization: Heuristic and Adaptive Techniques," edited by David W. Corne, Martin J. Oates and George D. Smith. In the last two decades, wireless communication systems such as cordless phones, paging systems, wireless data networks, satellite-based and cellular mobile systems have been steadily increasing in both popular importance and technological sophistication. The twin goals of this chapter are to familiarize mobile communication engineers with global search techniques and their potential, and to provide those interested in these techniques with an idea of the nature and scope of their application to mobile communications.

Smart antennas constitute a promising hut still emerging technology. Space-time processing algorithms provide powerful tools to enhance the overall performance of wireless cellular networks. Improvements, typically by a factor of two in cell coverage or capacity, are shown to be possible according to results from field deployments using simple beamforming. Greater improvements can be obtained from some of the more advanced space-time processing solutions described in this paper. The successful integration of space- time processing techniques will however also require a substantial evolution of the current air interfaces. Also, the design of space-tune algorithms must also he application- and environment-specific. [ABSTRACT FROM AUTHOR]

The article discusses simulation of wireless network systems. Simulation is a general term that is used in many disciplines including performance evaluation of computer and telecommunications systems. A model is a description of a system by symbolic language or theory to be seen as a system with which the world of objects can be expressed. The article also reviews the main characteristics of the commonly used stochastic distributions used for the simulation of wireless networks. The article concludes with cases studies on the simulation of some wireless network systems.

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.

The article focuses on fixed wireless access systems. The goal of this chapter is to review the main techniques used for Wireless Local Loop (WLL) including the Multichannel Multipoint Distribution Service, and the Local Multipoint Distribution Service. It is expected that the global WLL market will exceed 202 million subscribers by the year 2005. Much of this growth will be in the developing countries where over half the world's population lacks Plain Old Telephone Service. WLL systems have a number of advantages over wired systems to subscriber local loop support.

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.

The article focuses on Point-to-multipoint (PMP) network architecture. PMP network architecture is the most widely used approach for electronic communication with a large number of destinations or nodes. It is used for wired telephone systems in which twisted wire pairs from each phone terminal are routed to a central office where calls are placed on shared trunk circuits for onward routing. The wired PMP networks provide service to discrete locations, whereas the wireless systems listed are designed to provide service to an area where the specific locations of the service users are usually unknown.

In the future, radio communication systems will offer different services through single user equipment; furthermore, it is expected that different radio communication systems will merge into one universal communication system. Today, there are two known concepts for providing wireless communication services: terrestrially based communication systems and satellite communication systems. Each concept has its specific characteristics, and consequently, advantages and disadvantages. The main disadvantages of terrestrially based systems are: poor radio channel quality, Rayleigh fading limits the cell radius and transmitted data rate and; and Terrain shadowing causes gaps in radio coverage.

The appendices (39 pages) give supplementary information on: queuing systems for traffic performance analysis, standards and recommendations of ISO, ITU, IEC, INTELSAT/INMARSAT, ATM Forum, CEN/CENELEC, CEPT, ETSI, ECMA, EBU, EUTELSAT, ESA and others. International Frequency Allocations, The Frequencies of European Mobile Radio Systems, The GSM Standard. [ABSTRACT FROM PUBLISHER]

Chapter 17 reviews the existing routing algorithms for wireless networks of nodes that are not aware of their geographic positions. Routing the message (finding a path between a source and a destination node) is a basic data communication protocol in mobile ad hoc networks, consisting of hosts that communicate without the assistance of base stations. [ABSTRACT FROM PUBLISHER]

Chapter 1 discusses the handoff, which is the mechanism for transferring an ongoing call from one base station to another as a user moves through the coverage area of a cellular system. Admission control is a related problem, in which the radio resource management system has to decide if a new call arrival, or a request for service or handoff may be allowed into the system. Four conventional handoff schemes in a voice-based, single traffic system are summarized and two handoff schemes for integrated voice and data wireless mobile networks are also covered in detail. [ABSTRACT FROM PUBLISHER]

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]

The article presents information about the fourth-generation mobile systems, technology to be used in the field of wireless communication systems. Fourth-generation mobile systems require high data-rate transmission, high mobility, wide area coverage, higher capacity and wireless QoS (quality of service resource control). The requirement for broadband wireless channels and guaranteed quality of service (QoS) will become more stringent in mobile data communications. There is an idea to include new communication systems such as Intelligent Transport Systems and High Altitude Stratospheric Platform Station systems at a research level.

Chapter Four covers modulation aspects. Especially it contains: a thorough presentation of the trellis coding modulation theory; aspects on the combination of trellis quantization and modulation schemes; an investigation of the performance of Combined TCQ/TCM scheme over the wireless local loop environment; an example of a 4‐state combined trellis coded quantization/modulation scheme over a WLL environment. [ABSTRACT FROM PUBLISHER]

Chapter Six covers a channel model analysis based on a series of measurements carried out at 2GHz designed to characterize a wide band WLL in a range of environments; An experimental procedure used in two measurement campaigns; The data processing stages used to determine the channel parameters; The channel model used. [ABSTRACT FROM PUBLISHER]

Chapter 10 focuses on the indoor system of BRAIN, a mm-waveband high-speed multimedia wireless LAN. It discusses the architecture and design of the prototype; a description of a wireless MAC protocol; the configuration and implementation of the system. [ABSTRACT FROM PUBLISHER]

Chapter 11 proposes a private branch exchange (PBX) based mobility manager for WLL, which allows users to receive wireless service at any location within the WLL service area. [ABSTRACT FROM PUBLISHER]

Focuses on the factors that led to the innovation of universal mobile telecommunication systems (UMTS). Increase in the mobile multimedia market; Emergence of new terminals or smart phones; Industrial opportunity of UMTS cited by manufacturers.

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]

In this chapter, a variety of state-of-the art planar antennas is presented, as well as several new active architectures that take full advantage of the high performance, low profile, low cost, and low weight of this still developing field of antennas. While the broad scope of research that has been done in the areas of planar antennas and AIA systems in the last few decades prevents a comprehensive overview, it is hoped that the examples and issues discussed in this chapter provide a sufficient "flavor" of the field to show its true potential. [ABSTRACT FROM PUBLISHER]

Most of the modern telecommunications operators who are applying for radio spectrum allowing them to operate WLL (Wireless Local Loop) services are planning to offer a multimedia portfolio of voice and broadband data services. This chapter describes the different classes of equipment which have been developed by equipment manufacturers as a means for offering 'broadband wireless access'. In addition, it discusses the specific considerations which should accompany the planning and operation of such a network. [ABSTRACT FROM PUBLISHER]

This chapter conveys a deeper understanding of the roots of the software radio. This includes the technical evolution that has resulted in today's emphasis on SDR, and it includes the management motivations toward realizing appropriately tailored implementations. The chapter begins with an introduction to technology-demographics, a method for studying architecture. The chapter then characterizes the need for software-radio architecture. Because of the intense interest of the commercial and military sectors, and because of the fragmentation of industry into competing groups, there are competing goals for software radio evolution within standards organizations. These goals are considered in some detail since they set the stage for the competition of technical ideas. The chapter concludes with a roadmap of software-radio architecture evolution, and a section of exercises for the reader. [ABSTRACT FROM PUBLISHER]

This chapter analyzes node-level software radio architecture. Attention turns to the internal functions, components, and design rules within a radio node. The node-level architecture analysis treats cost and other externally imposed design constraints (e.g., standards) as explicit design rules. The chapter concludes with exercises for the reader. [ABSTRACT FROM PUBLISHER]

The material covered in this chapter can reduce DSP hardware costs by a factor of 2 : 1 or more. Thus it is pivotal and in some sense the culmination of the SDR design aspects of this text. A section of reader exercises appears at the end of the chapter. [ABSTRACT FROM PUBLISHER]

Not all carriers operating near the same frequency band offer essentially the same coverage choices. Design trade-offs are made between area coverage and its close cousin, building penetration, versus subscriber capacity. These trade-offs flow from fundamental decisions on channels allocated for data versus control, channel reuse philosophy, base station quantity and location, transmit power levels, FM capture exploitation, bit rates, and message redundancy-to name just a few. These trade-offs are discussed in this chapter. [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]

This chapter is a simplified look at some nonhardware technologies, protocols, and communication standards that drive both network and device development. The focus is on modulation techniques, error detection/correction, and data compression. [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]