A small PBX system is designed and implemented for an integrated service of vice and data switching. It is primarily a PCM switching system for telephone, that has an additional function of data switching. The messages are parallelly processed and switched through one stage time-slot interchange network.
System structure and operating procedure are discussed in detail. Among many sub-systems, the T-switch for the system, the Signaling Process Unig (SPU) and the Data Line Card (DL/C) for data switching are mainly studied and implemented. The SPU is a queueing buffer for data signaling in between switching processor and switching network. The DL/C is the interface between a serial data terminal and the switching network. It has the function of serial/parallel conversion and supervision. The data terminal is assumed to be asynchronous terminal with baud rate from 110 to 4800 bps.
The experimental results for the above subsystems and overall system performance are discussed.
전화 교환용 PCM-PBX에 Data 교환기능을 첨가한 한 소형 integrated switching system을 연구 개발하였다. 이 system의 통화로 ( speech path ) 는 Switching Memory 와 Adress Memory 로 구성된 1 stage 의 T-Switch(Time Slot Interchange)로 구성하였다. Highway 와 switching Network 내부에서 신호를 parallel 로 처리하여 192가입자가 처리될 수 있도록 하였다.
Data terminal 가입자를 위한 Data Line Card 와 Data Signaling 을 처리하기 위한 Siqnaling Process Unit를 설계 구성하였다. Data rate 는 110~4800 인 Asynchronou terminal을 사용할 수 있다.
Data switching system 의 Bit Error Rate 는 $3 × 10^{-4}$ 으로 측정되었다.
