Traffic control in a heterogeneous mobile tactical network with autonomous platforms

Future military operations will involve autonomous platforms and systems. In order for these systems to fully achieve their potential, the autonomous platforms need to collaborate. Each platform might have its own independent role in the autonomous system, but they will all work together to reach the same common goal. Hence, an efficient military autonomous system will be highly dependent on a communication network where traffic control is required to better utilize the resources. Through traffic control, the network can discriminate between several levels of importance, routing traffic along different performing network paths. Our motivation for this work was to gain experience with Software Defined Networking (SDN) as a tool for designing and experimenting with new network functionality in an environment where the radios are developed for operational use. Our objective was to gain experience by running SDN along with traditional routing in a heterogeneous network consisting of autonomous platforms. SDN was used as a tool to employ traffic control, so that we could intercept and further traffic engineer-specific traffic along with ordinary routing. Different traffic types were forwarded dependent on the capabilities of the radio networks. Our testbed consisted of different autonomous platforms, i.e. Unmanned Aerial Vehicle (UAV), Unmanned Ground Vehicle (UGV), and Unattended Ground Sensor (UGS). An experiment with the testbed was performed at Rygge Aerodrome where most elements of the testbed were tested, except physical elevation of the UAV platform. Through the experiment, several challenges were identified. In collaboration with Kongsberg Defence & Aerospace (KDA), we have implemented and tested SDN as a tool for traffic control using UAV. SDN with the help of the OpenFlow protocol and the Ryu SDN controller was installed by KDA on one of their broadband military radio models. Based on this implementation we could write our own network functionality, and thus easily customize traffic control. OpenFlow provides us with a tool where we can customize network functionality at a low cost in terms of coding hours. In our experiment, the traffic was relayed by intermediate nodes, due to the distance and traffic type, either on the ground or in the air. Military Ultra High Frequency (300–3000 MHz) (UHF) and Very High Frequency (30–300 MHz) (VHF) frequency bands were used for connectivity. OpenFlow was used for traffic control within the UHF radio network, and between the UHF and the VHF radio networks. By using OpenFlow we were able to customize how traffic should be handled by the network. This report is mainly written for network designers interested in SDN and autonomous systems in the tactical domain. The report focuses on design choices in an SDN network and on our observations in an experimental SDN network.