DCS BANDWIDTH REQUIREMENTS FOR CBTC AND CCTV
C C Bantin · WIT transactions on the built environment · 2004
DCS design philosophy is to deal with adverse conditions when they arise rather than to try to minimize occurrence. This means using packet retransmission rather than forward error correcting, to use contention-based access rather than deterministic access, to use frequency hopping spread spectrum rather than to try to guarantee interference-free spectrum. DCS is required to meet stringent service availability requirements in addition to a high equipment availability. The requirements for both CBTC and CCTV have been analyzed as well as the performance needed from a DCS that meet these requirements. As a result it has been demonstrated that although the system can technically operate in as little as 8 MHz of bandwidth (for both CBTC and CCTV) which is the minimum practical bandwidth required to give the level of service needed in an interference environment.