Routing and Admission Control in Networks

摘要

The provisioning of quality-of-service (QoS) for real-time network applications may require the network to reserve resources. A natural way to do this is to allow advance reservations of network resources prior to the time they are needed. We consider several two-dimensional admission control problems in simple topologies such as a line, a ring and a tree. The input is a set of connection requests, each specifying its spatial characteristics, that is, its source and destination; its temporal characteristics, that is, its start time and duration time; and, potentially, also a bandwidth requirement. In addition, each request has a profit gained by acommodating it. We address the related admission control problem, where the goal is to maximize the total profit gained by the accommodated requests. We provide approximation algorithms for several problem variations. Our results imply a 4c-approximation algorithm for finding a maximum weight independent set of axis-parallel rectangles in the plane, where c is the size of a maximum set of overlapping requests.