Modeling the performance of priority queueing for space communication

Due to the renewed interest in space exploration in recent years it is expected that the demand for communication services in space will massively increase. As the demand rises, timely and reliable communication becomes a crucial requirement for future missions. Recently traffic prioritization has been demonstrated as a mechanism to improve the quality of service for time-critical data. In this work we propose a mathematical model that describes the delay impact of traffic prioritization on space communication links. Based on a D/M/1 system with two non-preemtive priority classes that captures both retransmission delays over an unreliable channel and queueing delays we derive the full delay distribution for the high priority data. Validated against an extensive simulation campaign across a range of utilizations and priority shares, the model provides an approximation on the Quasi-Realtime probability (the probability of end-to-end delay below 2.5 s), with errors below 5 % at low utilization and up to 38 % at high utilization with a high priority share. For the average delay, the model matches simulation almost exactly across all tested configurations.

Content

Subjects

Space Communication

Solar System Internet

Queueing Theory

Priority

Quality of Service

DDC Class

621.38: Electronics, Communications Engineering