Distributed Microprocessors Control Architecture for Versatile Business Communications

This paper describes the NEAX®2400 Information Management System (IMS), which is no longer a conventional telephone switching system, but is instead a switching hub for various office automation equipment. The NEAX2400 IMS not only provides various circuit-switching functions such as conventional voice communication (telephone) switching, low-speed and high-speed data switching, but also provides stored and forward capabilities for voice (voice mail) and data (text mail, facsimile mail, etc.). This paper especially emphasizes the basic EPBX features and functions of the NEAX2400 IMS. The standard 64 kbit/s PCM technique is used for digitalization of voice signals, and switched through a nonblocking architecture time-division digital network. All digital data signals are transmitted through the same time-division digital network at the 64 kbit/s rate intermixed with digital voice signals. The controls of the switching functions, station service features, and maintenance service are performed by functionally divided distributed microprocessers. The most outstanding attribute of the NEAX2400 IMS is the unique building-block architecture of the equipment configuration. Modules are stacked above the basic module as the number of line and trunk ports, or additional stored and forward features are required. Up to four additional modules can be stacked up as a single module group. This unique arrangement permits the NEAX2400 IMS to be very flexible in its system applications and expandability. Practically, the NEAX2400 IMS will economically service as few as 184 ports (mixture of voice/data, line/trunk) and can be continuously expanded to as many as 23 184 ports.