| 摘要 |
PURPOSE:To attain economy by attaining the use of a transfer path of number information to a central controller for a dial pulse signal (DP) in case of both the DP signal and a PB signal to simplify the reception of number information of the central controller. CONSTITUTION:An audible tone such as a dial tone to a subscriber line is transmitted from a subscriber line concentration stage device LC via an outgoing path of a line concentration network device LL not through the path of a network device NN. Number information is transmitted to a PB signal receiver PBREC via the outgoing path of a four-wire path set to the network device NW after the end of reception of the PB signal. The line concentration stage controller LLC is provided with a function which supervises the outgoing path of a four-wire path, receives the number information from the PB signal receiver PBREC and informs the said number information to the central controller CC via a number information path LDP for the DP signal. The number information path LPB for the PB signal, a PB signal receiver PBREC relating to the said number information path LPB, and parts relating to transmission/reception of number information of the central controller CC are eliminated. |
