Bisnd Essay Research Paper Date sent

Bisnd Essay, Research Paper

Date sent: Sat, 27 Apr 96 17:56:40 0100INTEGRATION OF UMTS AND B-ISDN – IS IT POSSIBLE OR DESIRABLE.INTRODUCTIONIn the future, existing fixed networks will be complemented bymobile networks with similar numbers of users. These mobileusers will have identical requirements and expectations to thefixed users, for on-demand applications of telecommunicationsrequiring high bit-rate channels. It will be necessary forthese fixed and mobile networks to interoperate in order topass data, in real time and at high speeds, between theirusers. But how far must this interoperation be taken. How muchintegration of the fixed and mobile network structures isneeded. Here, a fixed network, B-ISDN, and a mobile network,UMTS, under development at the same time, are examined to seehow well and closely they should work together in order tomeet expected user needs. Work already taking place on this isdiscussed. BACKGROUNDThe Universal Mobile Telecommunication System (UMTS), the thirdgeneration of mobile networks, is presently being specified aspart of the European RACE technology initiative. The aim ofUMTS is to implement terminal mobility and personal mobilitywithin its systems, providing a single world mobile standard. Outside Europe, UMTS is now known as International MobileTelecommunications 2000 (IMT2000), which replaces its previousname of Future Public Land Mobile Telecommunication System(FPLMTS). [BUIT95]UMTS is envisaged as providing the infrastructure needed tosupport a wide range of multimedia digital services, orteleservices [CHEU94], requiring channel bit-rates of lessthan the UMTS upper ceiling of 2 Mbits/second, as allocated toit in the World Administrative Radio Conference (WARC) ‘92bands. UMTS must also support the traditional mobile servicespresently offered by separate networks, including cordless,cellular, paging, wireless local loop, and satellite services. [BUIT95] Mobile teleservices requiring higher bit rates, from2 to 155 Mbits/second, are expected to be catered for byMobile Broadband Services (MBS), the eventual successor toUMTS, which is still under study. [RACED732]Broadband Integrated Services Digital Network (B-ISDN),conceived as an all-purpose digital network that willsupersede Narrowband ISDN (N-ISDN or ISDN), is also stillbeing specified. B-ISDN, with its transport layer ofAsynchronous Transfer Mode (ATM) is expected to be thebackbone of future fixed digital networks. [MINZ89]It is anticipated that, by the year 2005, up to 50% of allcommunication terminals will be mobile. [CHEU94] The MobileGreen Paper, issued by the European Commission in 1994,predicts 40 million mobile users in the European Union by2000, rising to 80 million by 2010. This gives mobile users animportance ranking alongside fixed-network users. [BUIT95]One result of this growth in mobile telecommunications will bethe increase in teleservice operations that originate ineither the fixed or mobile network, but terminate in theother, crossing the boundary between the two. UMTS is expectedto be introduced within the next ten years, and integrationwith narrowband and broadband ISDN is possible in this time. Interoperability between UMTS and ISDN in some fashion will benecessary to support the interoperability between the fixedand mobile networks that users have already come to expectwith existing mobile networks, and to meet the expectation ofconsistency of fixed/mobile service provision laid out in theinitial RACE vision. [SWAI94]One way of making UMTS attractive to potential customers is tooffer the same range of services that B-ISDN will offer,within the bounds of the lower 2 Mbits/second ceiling of UMTS. [BUIT95]So, with the twin goals of meeting existing expectations andmaking UMTS as flexible as possible to attract customers, howclosely integrated must UMTS be with B-ISDN to achieve this.ALTERNATIVES FOR INTEGRATING UMTS WITH OTHER NETWORKSThe UMTS network could be developed along one of the followingalternative integration paths:1. Developing an ‘optimised’ network structure and signalling protocols tailored for the special mobile requirements of UMTS. This would be incompatible with anything else. Services from all fixed networks would be passed through via gateways. This design-from-scratch method would result in highly efficient intra-network operation, at the expense of highly inefficient inter-network operation, high development cost, scepticism relating to non-standard technology, and slow market take-up. True integration with fixed networks is not possible in this scenario. Given the drawbacks, this is not a realistic option, and it has not been considered in depth. One of the RACE goals was to design UMTS not as a separate overlay network, but to allow integration with a fixed network; this option is undesirable. [BUIT95]2. Integration with and evolution from the existing Global System for Mobile telecommunication. (GSM, formerly standing for Group Special Mobil during early French-led specification, is now taken as meaning Global System for Mobile communications by the non-French-speaking world.) GSM is currently being introduced on the European market. This option has the advantage of using already-existing mobile infrastructure with a ready and captive market, but at the expense of limiting channel bit-rate considerably, which in turn limits the services that can be made available over UMTS. Some of the technical assumptions of UMTS, such as advanced security algorithms