 exercise as care needs to be taken to ensure that priate FP. A base controller synchronises this re-routeing of calls. PP there are no unfavourable reactions with similar devices already in periodically scan all channels to update their list of free channels to place on long distance connections, e.g. over a satellite link. ease handover. Link quality is assessed from channel bit error ratios and received signal strength. 49.4.8 Implementation For handover the PP requests a second channel (perhaps on another FP) to be modulated with the wanted signal. The PP then To achieve success the basic production cost of DECT must be low. decides when to switch channels and then informs the controller Thus the same objectives that were seen to be important to which channel to release. CT2/CAI's cost basis are equally applicable to DECT, i.e. the PHL Packet MAC Data MAC Packet C/P/Q Figure 49.12 PHL and MAC Layer responsibilities References 49/13 adoption of common components and large scale production to ETSI (1992c) Digital European Cordless Telecommunications Ref- achieve the full cost benefits of scale. erence Document, ETSI Technical Report. Furthermore, equipment installation practices must be developed Evans, M. W. (1990) CT2 Common Air Interface, British Telecom that can guarantee standards of communication quality that the Technical Journal, 9, (2), pp. 103-111. customer has come to expect from the more conventional wired terminal equipment. Holmes, D. W. J. and Swain, R. S. (1990) The Digital Cordless Telecommunications Common Air Interface, British Telecom Technical Journal, 8, (1), pp. 12-18. 49.5 References Ochsner, H. (1990) Radio Aspects of DECT. In Proceedings of the Fourth Nordic Seminar on Digital Mobile Radio Communica- tions (DMR IV), 26th-28th June, Oslo, Norway. ETSI (1991) Common Air Interface Specification to be used for Interworking between Cordless Telephone Apparatus in the Swain, R. S. (1985) Cordless Telecommunications in the UK, Brit- Frequency Band 864. 1MHz to 868.1MHz, Including Public Ac- i