JPS6471259A - Private branch telephone exchange - Google Patents

Abstract

PURPOSE:To improve the communication efficiency, by grouping telephone sets connected to a private branch exchange, registering the number and connecting the telephone set to other telephone set in the group by the operation of the caller side when the communication is disabled from the called telephone set. CONSTITUTION:Optional extension sets (e.g., 9-11) are registered as one and same group to a storage section from an operation console 8 via a control section 5. For example, in dialing a telephone set 9 from a telephone set 2, a dial signal PB is received by a PB signal receiver 4 via an extension 2a and a line circuit 31 and the control section 5 checks whether or not the telephone set 9 is busy by the signal from a PB signal receiver 4. When the set is not busy, the control section 5 controls the network section 1 to send a signal to the telephone sets 2, 9 to connect them, but when the telephone set 9 is busy, a busy tone is sent to the telephone set 2. When the set 2 dials a specific number, the idle state of telephone sets 1-, 11 of the same group as the telephone set 9 is checked from the storage section 7 via the PB signal reception section 4 and the control section 5 to apply connection. Thus, the calling efficiency is improved.