Towards a routing framework in ad hoc space networks

The unique characteristics of space networks lead to different research approaches from those in terrestrial networks. In this paper, a routing framework called Space Gateway Routing (SGR) is proposed for routing through different autonomous regions (ARs) in ad hoc space networks. SGR has two integral parts: External SGR (ESGR) and Interior SGR (ISGR). ESGR addresses the delivery of different traffic types through ARs. Inside ESGR, the Location-Predicted Directional Broadcast (LPDB) is proposed for fast delivery of remote control messages and automatic data delivery. The Receiver-Initiated On-demand Routing (RIOR) is proposed for controlled data delivery, where the route discovery is initiated on-demand by the receiver, and routing tables are maintained in soft state at intermediate nodes. ISGR exchanges inter-AR routing information among border routers within an AR and schedules interAR message transmission. The Longest Queues (LQ) policy is proposed for contact allocation for AR border routers, and the Minimum Waiting (MW) policy is introduced for scheduling inter-region messages through an AR. Simulation results show that LPDB and RIOR are efficient both in message delivery and power consumption, and a combination of proposed LQ and MW policies achieves good delay and through-