Lower Bound on Bandwidth and Channel Assignment Algorithm for Multimedia Communication in Cellular Networks

摘要

Channel assignment problem in hexagonal cellular networks for multimedia services in a 2-band buffering environment is addressed here. We consider the simplest case of only two types of multimedia services, each having different bandwidths. We first derive lower bounds under different conditions on the minimum bandwidth requirement for assigning multimedia channels to a seven-node subgraph of the hexagonal cellular network by using a novel technique where assignment of different types of signals to support multimedia services are interleaved in the assignment process for the minimum bandwidth. We next propose a multimedia channel assignment algorithm to satisfy the non-homogeneous demands at each node of the network. To evaluate the performance of our proposed algorithm, we present new benchmark instances for multimedia communication. Our proposed algorithm, when run on different benchmark instances, comes up with assignments which require a minimum of 7 percent and a maximum of 40 percent more bandwidth than their corresponding lower bounds. The execution time for all the modified Philadelphia benchmark instances defined on a 21-node network is always within 265 milliseconds on an HPxw8400 workstation, while that for the modified benchmark instances defined on a 55-node network is within 733 milliseconds.