Aeronautical Gateways: Supporting TCP/IP-based Devices and Application over Modern Telemetry Networks

Modern telemetry networks require the use of efficient domain-specific protocols at the transport, network, and routing layers. However, the existing end-devices and services are based on legacy protocols such as TCP/IP. This necessitates translation between the legacy and aeronautical protocol. In this paper we propose an efficient translation mechanism with the help of gateways at the telemetry network edges. INTRODUCTION and MOTIVATION Telemetry applications in the mobile airborne networks pose unique challenges. In the current underlying network infrastructure these applications rely on point-to-point links based on IRIG 106 standard for serial streaming telemetry (SST) [1]. Source and destination nodes should be in range of each other using the point-to-point links. In a scenario where a direct communication link is not possible between source and destination, a multi-hop network can be the only feasible solution for providing an end-to-end communication path. The need to support real-time telemetry applications in the limited radio spectrum, combined with economical benefits using a networked telemetry system is recognized by the DoD [1]. However current network protocols (e.g. TCP/IP) cannot support the proposed networked telemetry systems, because these protocols make assumptions for the environment they operate that does not hold in the highly mobile aeronautical environment. This necessitates development of new protocols for the iNET program [1] proposed by the DoD. A preliminary communication network system for the iNET program is presented in [2, 3]. Network elements in the iNET environment is shown in Figure 1. The proposed networked system for telemetry applications include three types of network nodes: test articles (TA), ground stations (GS), and relay nodes (RN). TAs house the telemetry equipment and they are the airborne vehicles. The temeletry data can be sent to GSs directly for processing. If there is no direct communication link between the TA and GS, RNs, which are airborne vehicles, can relay the data to the destination. In such a highly mobile environment International Telemetering Conference (ITC 2009) where relative speeds can reach up to 7 Mach [4], current TCP/IP networking protocols fail to provide communication paths. 16 July 2008 AeroTP, AeroNP, AeroRP – iNET F2F Meeting 3 2 © James P.G. Sterbenz ITTC Airborne T l metry Networking Scenario and Environment • Very high relative velocity – Mach 7 ! 10 s contact – dynamic topology • Communication channel – limited spectrum – asymmetric links • data down omni • C&C up directional • Multihop – among TAs – through relay nodes GS GS TA