System for switching multirate digitized voice and data

A system for efficiently switching time multiplexed digital signals of different bit rates. A switch is described including switch modules each of which can switch data and/or voice 56 kilobit/second (kb) full-rate channels and 2.4 kb, 4.8 kb, and 9.6 kb subrate channels. All signals from incoming channels are stored in a signal memory and are transmitted to outgoing channels under the control of addresses stored in a control memory. The frame offset of each channel with respect to a standard superframe is detected and used to calculate the addresses to be stored in the control memory. Various arrangements are shown to minimize high speed signal and control memory requirements, and to simplify the process of generating control memory contents.