Requirements for a telecommunications network are becoming diversified in accordance with progress in social activities. To meet flexibly variable requirements, the telecommunications network should be provided with high capability exchange systems. For such a purpose, the stored program controlled (SPC) switching system may play a key role. In order to process calls in the telecommunications network environment, a signaling system is inevitable. In the telecommunications network, composed of electronic switching systems, the interoffice signaling system should be efficient when handled by a stored program. This paper describes modeling of interoffice signal processing and formulates parameters evaluating signal processing effectiveness. As a numerical example, multifrequency (MF) and common channel (CC) signal processings for a 9 digit transit call in a toll originating switching system served by D-10, N.T.T.'s commercial switching system, are analyzed in an assumed environment of the present analog and the future digital telecommunications network. From the result of this analysis, the paper concludes that a common channel signaling system is effective in the present analog network from the SPC viewpoint. If a digital environment is assumed in the future, a multifrequency-like individual channel signaling system is considered to be effective due to the improvements in dialed number transfer, inherent easy channel state recognition and no necessity for a continuity test. It is also suggested based on the interoffice signal processing analysis to use a common channel signaling system as an interoffice data link between switching offices and a data base, where data on routing (selected speechpath link) or subscriber are stored.

This paper presents a topological switch cell reduction method by introducing a new concept, called near full switch" (NFS) and evaluates throughput characteristics of NFS structures, when applied to communications networks.

Multiple communication Bus Network (MCNET) is proposed. This network interconnect, all exchanges in a specified area by one large scale transmission line to aim at network cost reduction and to secure adaptability for traffic variation.

This paper presents a way to quantitatively characterize switching processing features by information theoretical analysis. The analysis concept is based on understanding that a switching processor is an information processing machine for obtaining input information from subscribers and for sending output information to a speehpath network. In order to convert the input information to the output information, the switching system must choose a suitable internal action out of many possibilities, namely, the system has some entropy in making a decision on its response to the input information. The internal processing is considered, therefore, to contribute to decreasing the entropy. Based on the above comprehension on the switching system, an information processing evaluation principle and some parameters for control structure design are proposed. Using those parameters, partition and assignment way of processing amount to control stages or to switching functions such as input, internal and output processing are decided. Those parameters can be used also as measures of system flexibility or service variety and speechpath network control ease. Example figures of those parameters are given by analysis of a 7 digit rotary dialing intra-office call processing in a large scale stored program controlled model switching system. The values obtained can be considered to indicate the information processing level in the present switching system and may be also used to design quantitatively call processing capacity of a switching system and simultaneously to show an objective to be surpassed in future switching system development.