A data channel reservation protocol for high-speed processing in WDM single-hop networks

In WDM single-hop networks, a data channel reservation protocol to transmit variable-sized messages efficiently has been proposed. Networks have some data channels and a control channel to assign a data channel in the protocol. A timeslot of the control channel consists of several minislots and a round-trip propagation delay time between a node and the star coupler. Under the condition of long transmission distance or high bit rate, the round-trip propagation delay time is longer than the minislot part in a timeslot and consequently the throughput characteristics are degraded. In this paper, we propose a protocol to transmit variable-sized messages efficiently even under the above condition. In the proposed protocol, a permitted transmission timeslot (PTS) is set to transmit a control packet every (R + 1) timeslots, and a data channel is assigned to each transmitting node every (R + 1) timeslots where R is the propagation delay time normalized to the timeslot length. Then the performance of the proposed protocol is compared with that of the conventional one by computer simulation. The simulation results improved the throughput by about 30% at a message arrival rate of 0.4 message/timeslot/node and showed that the proposed protocol is useful under the above conditions. (C) 2002 Wiley Periodicals, Inc.