| 摘要 |
In a telecommunication exchange, all connections are set up digitally in packet switched manner, with speech being given priority. The exchange does not have switches as used in conventional telephone exchanges, but has a number of busses (GROUP 0 GROUP 1, etc.), each serving a number of subscriber's lines. A call between two lines both connected to the same bus is set up wholly using that bus, while a call between two lines in different groups is set up via inter-group circuits (IGC 1, IGCn). Trunk circuits (TCI) are connected to the group busses. In an alternative a common bus is used to which all group busses and all trunks have access. Although the busses shown are linear busses, loops can be used. <IMAGE> |
