TELEMETRY TRANSMISSION USING INVERSE MULTIPLEXING AND ASYNCHRONOUS TRANSFER MODE (ATM)

Abstract

The growing need to transmit larger telemetry streams from the receiving site to the processor location over greater distances is requiring newer and more creative techniques. This paper reports efforts to use Asynchronous Transfer Mode (ATM) technology and inverse multiplexing to provide an economical system to interface telemetry streams into the public network for reliable transmission. Cost savings are available immediately for programs that are willing to meet the synchronization criteria today. Lab testing has shown the feasibility of using cost efficient techniques for data transmission. This document describes the investigation that is currently underway that could provide a significant change to the way telemetry data is transmitted from receiver sites to data processing sites. Instead of using dedicated lines with dedicated bandwidth regardless of the program being supported, the approach that has been tested in a lab environment would allow the dynamic allocation of bandwidth using ATM over a variety of carrier services. The combination of ATM and inverse multiplexing allows telemetry data rates above 1.5 Megabits per second (Mbps) to be transmitted over multiple T1 (1.544 Mbps) lines. Previously, the only choice when data rates exceeded 1.5 Mbps was to use an entire DS-3 (45 Mbps). Now it is possible to transmit intermediate sized data rates (1.5 to 8 Mbps) by bonding multiple T1s to provide the desired data throughput.