Lightweight Signaling and Efficient Coupling Heuristic for Optical Star Networks MAC Protocols
Several MAC protocols have been proposed to prevent collisions on passive optical star networks. Time Division Multiple Access (TDMA) is a simple way to guarantee conflict-free concurrent transmissions on such networks. Because it does not require any signaling, TDM efficiency is not distance dependant. However, TDM suffers from non negligible access delays under low load. To reduce this drawback, dynamic allocation schemes (DAS) such as the Random Sheduling Algorithm (RSA) or the Group Time Division Multiplexing (GTDM) have been proposed. Both of these mechanisms reserves slots on a packet-bypacket basis by means of a signaling channel. The capacity in bit/s of this signaling channel is directly related to the number of buffers used in each node. The parallel queueing strategy allows to reduce the signaling cost by using a small number of buffers in each node. In that case, coupling algorithms such as the Minimum-degree Vertex First Scheduling (MVFS) have been proposed to manage the packets enqueueing/dequeueing process. In this paper, we propose a new MAC protocol for passive optical star networks which cumulates the benefits of GTDM in terms of lightweight signaling with those of the MVFS algorithm in terms of coupling efficiency. The performance of this new protocol is compared to other existing solutions by means of computer simulations. We also underline the disruptive influence of propagation delays on the DAS-type protocols efficiency.
KeywordsSingle-hop networks passive optical star MAC protocols performance evaluation.
- I. Cidon and Y. Ofeq, “Distributed Fairness for Local Area Networks with concurrent Transmission”, Proceedings of the 3rd International Workshop on Distributed Algorithms, pp. 57–69, September 1989.Google Scholar
- W. W. Lemppenau, H. R. Van As, H. R. Schindler, “A 2.4 Gbit/s ATM implementation of the CRMA-II dual ring LAN and MAN”, Proceedings of EFOCN’93,The Hague, 1993.Google Scholar
- H. Kasahara, K. Imai, N. Morita, T. Ito. “Distributed ATM ring-based switching architecture for MAN and B-ISDN access networks”, Proceedings of the first IFIP Conference on Broadband Communications, Estoril, 1992.Google Scholar
- R. Chipalkatti, A. S. Acampora, “Protocols for Optical Star-Coupler Network using WDM: Performace and complexity study”, IEEE Journal on, Selected Areas in Communications, Vol. 11, No. 4, May 1994.Google Scholar
- D. Guo, Y. Yemini, Z. Z.ang, “Scalable High-Speed Protocols for WDM Optical Star Networks”, Proceedings of IEEE Infocom, Vol. 3, pp. 1544–1551, Toronto,.lune 14–16, 1994.Google Scholar
- B. Kannan, S. Fotedar, M. Gerla, “A protocol for WDM Star Coupler Networks”, Proceedings of IEEE Infocom, Vol. 3, pp. 1536–1543, Toronto, June 14–16, 1994.Google Scholar