SUPPORT OF MULTIPLE MODULATION LEVELS FOR A CELLULAR TRAFFIC CHANNEL

摘要

A D-AMPS+ cellular communications air interface (50) is presented wherein a packet data control channel (40, 60) and packet data traffic channel (42, 62) are supported in addition to the conventional digital control channel (20) and digital traffic channel (22, 64). In particular, the packet data control channel, packet data traffic channel and digital traffic channel support multiple modulation level operation (high versus low). Procedures are provided for intracell (76, 80, 82) and intercell (92, 94, 96, 98) modulation transition of mobile station communications carried by a traffic channel. In particular, these procedures facilitate intracell and intercell modulation transition to a traffic channel using the same level of modulation, as well as intracell and intercell (fall-forward and fall-backward) modulation transition to a traffic channel using a different level of modulation.