Dynamic Resource Allocation for an IP-based Communications Network Supporting Space Exploration
Date: September 25 - September 28, 2005
We address issues related to efficiency, fairness, end-to-end delay minimization and Quality-of-Service (QoS) framework in order to enable a flexible access and dynamic mission operation capability in the next generation NASA space-to-ground IP-based communication infrastructure. In our scenario, the downlink channel of the NASA Tracking and Data Relay Satellite System is shared by a number of spacecraft, which we model as streams with different priority levels going through a common queue and a router. Both the current and future potential architectures for this relay system are addressed. We formulate an optimization problem for long-term static bandwidth allocation and present its solution to serve as initial bandwidth allocation algorithm and periodical regulation approach. Along with it, a hybrid Time Division Multiple Access (TDMA)-based protocol is proposed and then an assignment problem for the short-term dynamic optimal timeslot scheduling is studied. By using simulation, the performance of a suitable Medium Access Control (MAC) protocol with timeslot scheduling is analyzed and compared with that of the existing static fixed-assignment scheme.