Network Telemetry Link Throughput Maximization Approaches

Abstract

The use of Ethernet and Internet Protocol (IP) networking technologies in flight test instrumentation and telemetry systems is rapidly increasing, driven by the ubiquity, scalability, and flexibility of networking technologies. Networks first made a positive impact in ground station infrastructure and have recently been emerging in test article data acquisition infrastructure in programs such as the A380, 787, P-8A, and Future Combat Systems. The next logical step is to provide a two-way network telemetry link to fully extend the flexibility of the network between the test articles and ground station. The United States Department of Defense (DoD) integrated Network-Enhanced Telemetry (iNET) program is currently working to build a standardized network telemetry link for exactly this purpose. When developing a network telemetry link, the limited availability of telemetry spectrum must be considered and thus it is critical to choose system-level approaches to maximize the throughput achieved from the link. This paper first presents the statistics of the network data that would typically use this link based on empirical data from current network-based flight test instrumentation systems. Several approaches to using a network telemetry link are then presented. Predicted achievable throughputs of each approach are presented that are derived from the statistics of the empirical test data. Based on this, the paper presents recommendations for building systems using network telemetry links.