Mobile telephony

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

Method and apparatus for handoff control in mobile communications systems

Abstract: A mobile communications system includes a first base station (205) to service a first set of connections (225) from a first set of mobile communications devices (100) to a communications network (110). A set of neighboring base stations (210) is in communication with the first base station. In an embodiment of the invention, the first base station prioritizes the first set of connections according to first predetermined criteria and prioritizes the set of neighboring base stations according to second predetermined criteria. The prioritization lists are used in deterministic ways to alleviate potential congestion in backhaul links and optimize the overall performance of system and improved quality of service.

Probability distributions for the number of radio transceivers which can communicate with one another

Abstract: This paper considers points which can communicate with one another and which are uniformly and randomly distributed on the plane, assuming an inverse power law for attenuation and log-normal shadowing. First, a probability distribution is obtained for the distance between a pair of such points. Communication is assumed to be possible if the attenuation of a signal transmitted from one point, say a mobile phone, does not exceed some specified value by the time it reaches the other, say a base station. The probability distribution of the number of base stations which can hear such a signal from a given mobile is found. An example shows how the probability that a mobile is in a handover region between two or more base stations can be evaluated. The analysis is extended to the case where the power law changes at a specified distance from the mobile, and also to consider the effect of an area within the plane containing a greater density of mobiles and/or base stations (a hot spot). A final result gives the conditional distribution for the number of base stations within some specified area of the plane, given the number within some larger area containing that specified area. The results also apply to the number of mobiles within range of a base station and, in an ad hoc network, to the number of nodes within range of a given node.

RF system concepts for highly integrated RFICs for W-CDMA mobile radio terminals

Abstract: The standardization phase for third-generation wide-band CDMA systems like the universal mobile telecommunication system, which will add broad-band data to support video, Internet access, and other high-speed services for untethered devices is running toward its finalization. As is typical for mobile communication systems standardization, sufficient RF performance has been assumed and most efforts have been put to digital baseband issues. This is especially true for the mobile phone transceivers, the RF part of which is (although its baseband part is much more complex in terms of number of devices) still the bottleneck of the entire system. Meanwhile, in the RF concept engineering of today's commercial products, an accurate prediction of the needed RF performance by using RF system simulation is indispensable. This is, in particular, the case with third-generation wireless systems, which, from the RF design point-of-view, are quite different from second-generation time-division multiple access/frequency-division multiple-access systems due to the fact that the user signals are now separated in the code domain rather than in the time and/or frequency domain. The paper gives an insight of how to derive receiver requirements for third-generation mobiles in terms recognizable by microwave designers, reports on the system simulation-based design, and performance of silicon-based RF integrated circuits for mobile terminal use, and discusses some future technologies and techniques and their possible impact on portable wireless devices.

Systems and methods to secure transactions via mobile devices

Abstract: Systems and methods are provided to improve security of payment transactions via mobile communications. In one aspect, a system includes an interchange having a common format processor and a plurality of converters to interface with a plurality of different controllers of mobile communications. The converters are configured to communicate with the controllers in different formats and to communicate with the common format processor in a common format for the confirmation of payment requests, made via mobile phones. The common format processor is to determine a risk of a payment request being fraudulent based on the personal identification information associated with a mobile phone and, after the payment request is confirmed and when the risk is below a threshold, to communicate one or more premium messages to the mobile phone to collect funds to fulfill the payment request.

Gsm and umts : the creation of global mobile communication

Abstract: From the Publisher: GSM (Global System for Mobile communication) provides a service to more than 500 million users throughout 168 countries worldwide. It is the world market leader serving 69 % of all mobile digital users and is currently evolving into UMTS (Universal Mobile Telecommunication System). By describing the critical decisions and the phases of the development this key text explains how the GSM initiative became a success in Europe and how it evolved to the global mobile communication system. Initially the strategy and technical specifications were agreed for Europe and the subsequent evolution to a global solution was achieved by incorporating all non-European requirements and by inviting all committed parties worldwide to participate. The process started in 1982 and the first GSM networks went into commercial service in 1992. The first UMTS networks are expected in 2002 and the fourth generation discussions have begun. *Presents a complete technical history of the development of GSM and the early evolution to UMTS *Clarifies the creation of the initial GSM second generation system in CEPT GSM, the evolution to a generation 2.5 system in ETSI SMG and the evolution to the Third Generation (UMTS) in ETSI SMG and 3GPP *Covers all of the services and system features together with the working methods and organisational aspects GSM and UMTS provides an interesting and informative read and will appeal to everyone involved in the mobile communications market needing to know how GSM and UMTS technologies evolved. The accompanying CD-ROM provides nearly 500 reference documents including reports of all standardisation plenary meetings, strategy documents, keydecisions, the GSM Memorandum of Understanding and the report of the UMTS Task Force.