Switching systems and switching software development in China

The architectures of two medium-sized digital telephone switching systems that were developed in China, the DS-30 and HJD-04 systems, are discussed. The DS-30 is a 30000 line digital telephone switching system, with a total capacity of 300000 busy hour call attempts (BHCA) using digital line concentration and a time-space-time switch fabric. Its architecture is a distributed control, multistage, multiprocessor system with load and function sharing. The HJD-04 is a 30000 line digital telephone switching system, with a total capacity of 2 million BHCA. The significant feature of the HJD-04 system is its switching network, which consists of a single time switch. The structure of the switching software support environment used in China is discussed.<
>