Mobile telephony

About: Mobile telephony is a research topic. Over the lifetime, 38008 publications have been published within this topic receiving 553646 citations.

WCDMA for UMTS: HSPA Evolution and LTE

Abstract: As wireless communications technologies evolve, Wideband Code Division Multiple Access (WCDMA) seems a strong candidate for providing multimedia to the handset, as well as Universal Mobile Telecommunications Services (UMTS)--which is to say common wireless communications standards over most of the world. WCDMA for UMTS sets out to decipher the standards documents of the Third Generation Partnership Project (3GPP). Specifically, this book deals with the 3GPP documents on Frequency Division Duplex (FDD) and Time Division Duplex (TDD) for Universal Terrestrial Radio Access (UTRA). This book should prove valuable to readers who plan to implement WCDMA in hardware designs or service offerings. A series of engineering problems make up the backbone of the book, and each part of the deployment process is explained via text and calculations. For example, in the discussion on planning a radio network for WCDMA service provision, the book explains precisely how to take into account requirements (for quality of service, user capacity, and coverage) and conditions (such as terrain). Readers get formulas into which they can plug relative traffic predictions for voice, real-time data, non-real-time data, and overhead. There's also an explanation of how to interpret the formula output for deploying antennae. This is a serious engineering handbook for those who are involved in deploying WCDMA. --David Wall Topics covered: Wideband Code Division Multiple Access (WCDMA)--what it is, and (especially) how to implement it in a wireless network. Radio interface protocols, packet traffic, and network planning all are covered.

BLUETOOTH—The universal radio interface for ad hoc, wireless connectivity

Abstract: that is small enough to fit inside any electronic device or machine, that provides local connectivity, and that creates a (worldwide) micro-scale web. What applications might you use it in? In 1994, Ericsson Mobile Communications AB in Lund, Sweden, initiated a study to investigate the feasibility of a low-power, low-cost radio interface between mobile phones and their accessories. The intention was to eliminate cables between phones and PC cards, wireless headsets, and so forth. The study was part of a larger project that investigated multi-communicators connected to the cellular network via cellular telephones. The last link in the connection between a communicator and the cellular network was a short-range radio link to the phone—thus, the link was called the multicommunicator link or MC link. As the MC link project progressed, it became clear that there was no limit to the kinds of application that could use a short-range radio link. Cheap, short-range radios would make wireless communication between portable devices economically feasible. Current portable devices use infrared links (IrDA) to communicate with each other. Although infrared transceivers are inexpensive, they • have limited range (typically one to two meters); • are sensitive to direction and require direct line-of-sight; • can in principle only be used between two devices. By contrast, radios have much greater range, can propagate around objects and through various materials, and connect to many devices simultaneously. What is more, radio interfaces do not require user interaction. In the beginning of 1997, when designers had already begun work on an MC link

Positioning GSM telephones

Abstract: Due to the FCC requirement that operators of mobile communications networks be able to accurately locate mobile callers requesting emergency assistance via 911 by the year 2001, there has been a lot of activity among cellular and PCS providers to examine cellular positioning options. This article examines positioning solutions for the GSM group of standards. Worldwide deployment of GSM systems is well underway, and the positioning characteristics of the various systems are similar. The authors examine the ability to derive position information from GSM signals, based on their May 1996 achievement of accurate position measurements using GSM. Features of GSM signals relevant to positioning are analyzed as well as results achieved and the authors' ongoing positioning trials. Finally, other issues related to GSM positioning and mobile phone positioning in general are covered.

Mobile Communications Design Fundamentals

Abstract: From the Publisher: The most recent addition to William C Y Lee's acclaimed series on mobile and cellular communications, Mobile Communications Design Fundamentals, Second Edition offers designers, researchers, and students an up-to-date, invaluable guide to the theoretical framework of mobile radio communications and how such systems are designed With an abundance of new material, this Second Edition covers leading-edge Personal Communications Service (PCS), microcell, and CDMA systems, providing all the theoretical and design knowledge and know-how needed to design with both present and future technology Useful as a professional handbook or as a senior/graduate level text, the book provides complete coverage of the differences between fixed and wireless radio systems, up to and including the new FCC-promoted PCS systems; an authoritative description of the mobile radio environment that gives engineers the necessary technical background to confidently select the appropriate radio technology; definitive, clearly presented design parameters for both the base and mobile units; troubleshooting approaches that help you anticipate the problems associated with each system and solve them when they arise; comprehensive guidelines for how to develop the system design and frequency plan and how to tackle all capacity issues, and new information on CDMA, a hot broadband radio technologyboosting microcell technology capacity with system planningbuilt in predictionanalyzing digital communication systemsand covering noncellular mobile radio systems, including those for data communication With more than half of the material in this new edition based on the author's own widely recognized research work, Mobile Communications Design Fundamentals is a book no one interested in the new wave in mobile communications can afford to miss

Routing method for Ad-Hoc mobile networks

Abstract: A routing method for supporting ad-hoc mobile communications within a radio communications network. The network comprises a plurality of mobile hosts including a source mobile host and a destination mobile host, and a plurality of radio communications links connecting together with mobile hosts. The method comprises measuring the stability of the communications links between neighbouring mobile hosts using an associativity based characteristic and selecting a communications route through the network from the source mobile host to the destination mobile host based on the stability of the communications links. The associativity characteristic is measured by each mobile host periodically transmitting and receiving identifier beacons (ticks) and updating the status of its corresponding links. The greater the number of ticks associated with a given link, the greater its stability. Use of the associativity characteristic enables the routing method to deal efficiently with mobile host migrations throughout the network.