A study of isochronous channel reuse in DQDB metropolitan area networks

The isochronous channel reuse problem (ICRP) on DQDB metropolitan area networks is investigated. Given a set of established isochronous connections and a set of isochronous requests, the goal is to use a minimal number of isochronous channels to service these requests. On the other hand, given a limited isochronous bandwidth, the goal is to establish a maximal number of isochronous connections. In the paper, the authors show that the ICRP is NP-complete. For the simplified ICRP (SICRP), in which all the established isochronous connections as well as the isochronous requests are of the same bandwidth, the authors suggest a tight lower bound and propose an efficient isochronous channel reuse algorithm (ICRA). Simulation results show that for the SICRP, the solutions obtained by the ICRA are very close to the lower bound which implies the proposed ICRA is very attractive. For a limited isochronous bandwidth, the number of successful established isochronous connections obtained by the ICRA is much more than that of the original DQDB isochronous channels allocation scheme