RANDOMIZED MODEL FOR OPTIMIZATION OF TELEMETRY SYSTEM DESIGN

Abstract

The telemetry system designed for the space vehicle requires to provide constant data output, including video and instrumentation to the telemetry/transmitter box through the mission. The video data captured from the space travel is always high demand for social media or mission purpose. However, the limited telemetry bandwidth for transmitting all the high quality video data to the ground station before the end of the mission drives the system level design challenges. There are operational flight instrumentation data which takes higher priority than the video data in the telemetry bandwidth allocation. A common design approach to output all the video data is to utilize the filled data or IDLE frame with many small size IPv4 datagrams of the video. As a result, there are some video data are dropped out by the ground received equipment due to an extended period of waiting time of the receiver to collect all the defragmented IPv4 datagrams and reconstruct to a large IPv4 packet. One solution to resolve this problem is to have the telemetry processing box handling the defragmented IPv4 datagram by holding fragmented IP datagrams and reconstruct a whole IP packet before sending it to the transmitter, and yet still maintaining the vehicle telemetry system performance. This paper is going to focus on this method by developing a system level simulation tool and analyze the performance of the vehicle.