Design and performance analysis of an integrated traffic control scheme for an optical packet-switched metro WDM ring network

In this paper, we propose a novel integrated traffic control scheme, called ITCS, which seamlessly supports connection-oriented and connectionless services for a previously proposed experimental optical packet-switched metro WDM network, HOPSMAN. ITCS aims to efficiently satisfy the diverse quality-of-service (QoS) requirements while retaining maximal network throughput. Through a flexible reservation scheme, ITCS avoids the receiver-contention problem inhered in current WDM network, achieving high statistical multiplexing gain for isochronous traffic. By employing constant mean rate reservation and with an effective distributed call admission control (CAC), ITCS establishes isochronous traffic connections only within a single ring time under normal loads and achieves exceedingly low VBR delay. Furthermore, we develop a novel approximation to acquire the accurate results of the expected connection setup delay by means of an M/G/m queueing analysis. Extensive simulation results show that the mean setup queueing time is in profound agreement with the analytic results, and that ITCS accommodates maximal isochronous traffic with remarkable QoS performance and still retaining exceptional aggregate system throughput.