THE USE OF PACKETIZED TELEMETRY IN INVERSE T1 MULTIPLEXING

Abstract

As the number of telemetry applications at sites increases, the need for a higher bandwidth link from site-to-site grows. The use of an inverse T1 multiplexer allows the site to utilize multiple T1 lines rather than more costly higher bandwidth lines. There are many advantages to using a recognized packet standard, such as IRIG-107/98, over simply routing the streams through T1 lines. One advantage is that there is a total separation of data stream clock from T1 transmission clock, reducing synchronization circuitry and overhead. Another advantage is that the use of packets also allows for a smooth reconstructed clock phase on the receiving site, creating a virtually seamless transmission of clock and data. And, finally, by using a recognized packet standard, the inverse T1 multiplexer may easily be integrated into ranging and telemetry systems already incorporating packetized telemetry. This paper will discuss the combination of packets and inverse multiplexing to achieve an expandable transmission system capable of delivering a high bandwidth data stream across multiple T1 lines.