Optimization of routing protocol for packet radio networks

Abstract

Dynamic adaptive routing is required to improve the survivability of a packet radio network. A protocol called Open Shortest Path First (OSPF) Version 2 has been selected to meet the requirement. The network connectivity status, which often changes rapidly in a highly mobile tactical environment (due to jamming and station outages/additions), must be updated dynamically and automatically by the protocol to maintain reliable network service. With fast updates, the topology database will be more up-to-date and routing decisions will be more optimum. However high update rate will consume more channel bandwidth and will have adverse impact on user traffic. The objective is to optimize the OSPF protocol such that the system will maintain acceptable performance under anticipated traffic loading and network scenarios. The timing parameters associated with the update process will be varied to determine the optimum settings. The updates are transmitted in OSPF packets called link state updates (LSUs). The LSU packets will compete with user traffic on channel utilization. To reduce the impact on user traffic, the OSPF protocol parameters will be optimized to reduce the overhead traffic. A detailed simulation model has been developed for this effort. We describe the use of the robust design method in conjunction with the simulation model to optimize the protocol for dynamic routing. The main advantage of the robust design method is to provide a disciplined approach for experimentation (i.e., with no need to run all possible combinations of the experiment) that is needed to determine the most influential control factors.