A transmitter is set to time division multiple access (TDMA) mode and allocated a first TDMA channel. In the TDMA mode, the additional TDMA channels are allocated to and deallocated from the transmitter, according a traffic demand at the transmitter, until all TDMA channels are assigned and the traffic demand reaches a threshold, whereupon the transmitter is switched to a frequency division multiple access (FDMA) mode, and assigned an FDMA channel. In response to traffic levels, the transmitter is switched to larger bandwidth FDMA channels and, optionally, to a concurrent FDMA-TDMA mode having a large bandwidth FDMA channel in addition to a number of TDMA channels. Optionally, switching the transmitter among TDMA mode, FDMA mode, and concurrent FDMA-TDMA mode is based, at least in part, on QoS, or time of day, or user statistics, or combinations thereof.