A PCS terminal architecture to access multiple networks

Emerging US personal communication services (PCS) networks are centered around seven air-interface standards and two network infrastructure standards. Due to the expected fragmentation of the US PCS market among different air-interfaces and fixed networks, the ability of providing US-wide roaming becomes a challenging problem to solve. One aspect of roaming among different networks with a single user terminal is the ability of communicating with different radios. This requires that the terminal includes the entire protocol stack needed for the communication between the user terminal and the base transceiver stations (BTSs). The other aspect of roaming is the ability of communicating with different types of fixed network entities which provide end-to-end call control, supplementary services provision and any new future service. In order to provide this ability, the terminal has to include the protocol stack(s) implemented at the network for the relevant service. In this paper, the terminal architecture for a US PCS trial standard, i.e. composite CDMA/TDMA (CCT) IS-661 is described. It is shown that an IS-661 terminal can be used to access various networks. A number of unique problems are identified as related to roaming among different types of networks