Performance of QoS system for Future Battlefield Networks

One of the major QoS goals for future battlefield networks (FBN) is to ensure multi-level precedence and preemption (MLPP). Ensuring MLPP is difficult, partly due to the networking architecture for FBN which consists of wired ¿red¿ network connected by encrypted wireless ¿black¿ network. The security requirements for FBN do not allow passing information from black to red networks. So when congestion occurs in the black network, it cannot send explicit congestion notification to red-side sources for preempting flows. To address MLPP, WIN-T networks use a red-side admission controller - QoS edge device (QED) - that preempts low priority flows during congestion. Another technology that MLPP for FBN is the QoS agent, which is a black-side agent that dynamically manages WAN router queues. Both of these agents have been shown to independently uphold MLPP. For this paper we evaluated the QoS performance when both these agents were simultaneously active. We compared the performance of a system that used a red-side admission controller with a system that used both a red-side admission controller and a black-side queue management agent. Our simulations and experiments showed that the later system increases the throughput of the high priority traffic as well as that of the overall traffic. In addition it also helps in avoiding priority inversion, a situation where low priority flow is granted access to the network while a high priority flow is denied network access.