Routing and Scheduling for Time-Shift Advance Reservation

Standard advance reservation (SAR) mechanisms have been proposed as a way to provision resources for high-bandwidth applications in order to provide QoS guarantees to users; however, variations in the available bandwidth on different links over time can lead to situations in which standard advance reservations must be pushed further into the future, leading to higher end-to-end delays. We introduce the concept of time-shift advance reservation (TSAR), which improves bandwidth utilization by making use of delay elements at intermediate nodes within the network. We describe the TSAR architecture and discuss various design and implementation issues. The routing and scheduling problem in TSAR networks is defined, and a routing and scheduling algorithm is proposed. We find that TSAR with the proposed algorithm minimizes latency for each request and reduces request blocking compared to standard advance reservation and immediate reservation approaches.