PURPOSE: To simplify mechanical structure and to allow a package to be freed at its position by dispersing time division switching circuits to various channel system circuit packages and forming by wiring bus constitution in a case.

CONSTITUTION: Subscriber's telephone sets 10, 11 and a local terminal 12 are connected to subscriber's circuits TDLCs 23, 24 with a time division switching function and a local trunk circuit TDTRK25 with a time division switching function respectively. The TDLCs 23, 24 and the TDTRK25 are connected to a control part CNT29 through a control signal bus 27. Time division switching circuits are included in the TDLCs 23, 24 and the TDTRK25 respectively to form respective packages. Talking signals outputted from the time division switching circuits are applied to a wired logic type or three-status type AND circuit through a channel bus 26 to find out the AND. The channel bus 26 is usually constituted of 8 lines, a control signal bus 27 consists of an address line and a bi-directional data line and both lines 26, 27 are wired in the case. Therefore, one time division switchboard can be constituted only by inserting one package into the case.