 in fact anywhere they want to. It will offer ISDN-type services such as The United Kingdom was one of the first countries to consider calling number identification, diversion, call back when free, call introducing PCN type services when its Department of Trade and waiting, etc. Industry outlined the concept of Personal Communications Net- works in its paper 'Phones on the Move' in January 1989. This paper 48.3.1 PCN and GSM expressed the government's intention to allocate Radio Spectrum within the range 1.7GHz to 2.3GHz. The government held the idea The personal communications networks which are to be introduced that 'telephones should be for people and not places', whereby small into the UK will be based upon GSM, but operating at 1.8GHz. personal communicators would allow access to the telecommunica- ESTI GSM was tasked with developing a version of GSM for tions network wherever that person should be. operation in the 1.8GHz range. The series of recommendations As the Department of Trade required that any personal communi- became DCS1800 (Digital Cellular System at 1800MHz). cations network should conform to a publicly available technical ESTI agreed to produce DCS1800 in two phases: standard and as an early introduction was required using up-to-date technology, the view was expressed that pan-European Digital Cel- 1. Phase 1 by January 1991 establishes the generic differences lular Technology would be a strong contender offering the following between GSM 900 and DCS1800. advantages: 2. Phase 2 establishes a common framework for both PCN and 1. Early implementation in line with pan-European digital sys- items. For Phase 1 the changes to the GSM900 standards were: 2. Cost benefits arising from economies of scale. 3. The possibility of having customers' equipment which can Increase in bandwidth from 25MHz to 75MHz in each direc- operate on both PCN and pan-European Systems. 4. Staying in the mainstream of European developments and tion. This has impacts on the signalling and some RF aspects. RF link definition t