International Connection of Plesiochronous Networks via TDMA Satellite Link

Digital transmission techniques are expected to spread throughout the fixed-satellite service in the near future. The introduction of digital satellite systems will lead to a new requirement regarding how to connect the satellite link with terrestrial digital networks. This paper presents a satellite/terrestrial digital interface that has been developed to interconnect 2.048 Mbit/s PCM terrestrial and INTELSAT TDMA links which are in the plesiochronous relationship. Major functions of the interface include frame slip control, compensation for path length variation, and rate and format conversions. This paper also describes the design and implementation of the developed equipment, and experimental results for signal impairment due to the frame slips and PCM multiplex standard conversion. The experimental results demonstrate that a large humber of bit errors are induced by frame slips for voiceband data transmission above 4800 bits/s.