Systems (200) and methods for providing voice communications over a cellular network (204, 212). A call setup message is communicated from a first communication device (FCD) to a second communication device (SCD) on a first communications channel (FCC) in a cellular network (CN) at a first data transfer rate (FDTR). In response to the call setup message, a stimulator packet is communicated to the CN on FCC at FDTR. The stimulator packet includes data of an amount that equals or exceeds a threshold value. In response to the stimulator packet, FCD (202, 214) and CN transition from a first channel mode to a second different channel mode. In the second channel mode, data is transmitted on a second communications channel (SCC) in CN at a second data transfer rate (SDTR) different than FDTR.