MODULAR TIME DIVISION SWITCHING SYSTEM

摘要

MODULAR TIME DIVISION SWITCHING SYSTEM The time-switch stages of a switching network are organized in identical multistage modules connected to peripheral modules by two-way time division digital multiplex links, and each containing a network message controller which connects to a central processing unit through two-way control signal links passing serial digital data at the same rate of transmission at which the multiplex links operate. The central processing unit communicates with the peripheral modules only through network message controllers which operate on a store and forward basis. The network modules, central processing unit, control signal links and network links are duplicated and the central processing units connect to the control signal links through central message controllers which are also duplicated and each of which can - i operate with either of the central processing units. Under high load conditions, the origination of low-priority messages to central processing is inhibited by the central message controllers by substituting a special repeated code signal instead of the normal repeated code transmitted to indicate an idle condition, causing the network message controllers to do likewise, so that the peripheral modules can respond by inhibiting, for example, the recognition of new calls for service. - ii