In this study, we explore the performance optimization conditions of a WDM network of passive star topology that uses a Multi-channel Control Architecture (MCA) to avoid both the data channels and destination conflicts. The adopted synchronous WDMA scheme exploits the propagation delay to assign the data channels to the stations whose control packets transmission was successful. Thus, effective bandwidth utilization is achieved. An approximate analysis based on Poisson statistics is developed in order to explore the performance measures optimization.

The key parameters affecting the behavior of a passive star WDM network are: control channel collisions, data channel collisions, propagation delay latency and destination conflicts. In this paper, we try to exploit the propagation delay latency as an acknowledgment time period to introduce a new network architecture and a suitable access protocol in order to avoid data channel collisions, achieving performance measures improvement and enhancing in this way bandwidth utilization.

The key idea of this study is the adoption of an asymmetric access strategy suitable for a WDM network architecture of passive star topology that uses the Multichannel Control Architecture (MCA). The asymmetric access strategy determines that the MCA exploits a separate control channel for the transmission of free stations, while the remaining control channels are used by the backlogged stations. The exchanged control information over the MCA is utilized to properly assign the data channels among the stations for transmission, improving data channels utilization. In addition, the access scheme effectively exploits the propagation delay latency as an appropriate attribute in order to totally avoid both the data channels collisions and the destination conflicts. Thus, we achieve essential performance improvement and bandwidth utilization enhancement. The proposed access strategy belongs to the synchronous transmission WDMA protocols. An analytic Markovian model for finite population without approximations is developed to derive the performance measures. The effect of receiver collisions is analytically examined. Extensive comparative results are investigated for different network parameters: stations population and MCA channels.

In this paper, an efficient traffic allocation technique and a slotted delay-sensitive WDMA protocol suitable for ring metropolitan area networks is proposed. Our purpose is to improve the limited bandwidth utilization that many WDMA protocols for MANs introduce, especially at high loads. This is achieved by: 1) applying an access algorithm to avoid data wavelengths and receiver collisions, and 2) introducing a multiple buffer architecture at each node with an effective buffer selection for transmission scheme that combines the priority criteria of receiver collisions avoidance and packet age. Thus, we obtain not only dropping probability and delay reduction, but also significant throughput enhancement. The required number of buffers per node to maximize throughput is investigated. Performance evaluation is provided by a discrete event simulation model based on self-similar traffic. Comparative results prove that the proposed architecture manages efficient bandwidth utilization as compared with other WDMA protocols, especially under high loads.

This paper examines appropriate protocols for high speed multiple access communication systems where the bandwidth is divided into two separate asymmetric channels. Both channels operate using slotted nonpersistent CSMA or CSMA/CD techniques. Free stations access the first channel while all retransmissions occur in the second channel. We define the stability regions and the rules for optimal bandwidth allocation among the two channels for improvement of the system performance in case of infinite population. Numerical results show that the optimal behaviour gives performance improvement as compared with the single channel system with the same capacity.

A new network architecture which uses several wavelengths as control channels for coordination of packet transmissions on the data channels for single-hop WDMA networks and passive star topology is introduced. The control information are distributed over the total control channels reducing the electronic processing bottleneck at one of the end stations. Time is divided into fixed size cycles. The proposed schemes adopt the slotted ALOHA protocol for the control and data multichannel systems and differ in the adopted policy for data packet transmission. An analytical model is developed for the performance measures evaluation based on Poisson approximations statistics and an infinite population. Numerical results are also discussed for the various control and data channels.