In this issue - Technically

In large complex aerospace sites, hard-wire communication systems require extreme versatility. Members of each test group need constant intercommunication, plus ability to monitor related groups, or to access a paging system. The group conductors need priority lines between themselves and their supervisor. The supervisor needs priority circuits to Command and Safety. Connections to base telephones, radio links, data processing, recording, remote field indicators, countdown clocks or other systems may also exist. During countdown, groupings will increase, decrease, or merge, so that networks may change rapidly from isolated conversations to conferences of over a thousand stations. These requirements, plus high reliability, generate unique system criteria.