A two-level TDM access protocol for IP support in WDM optical networks

This paper presents a new access protocol for constructing IP over photonic systems. The protocol is based on a two-level TDMA (time division multiplexing access) structure with wavelength division multiplexing (WDM). Many IP-based network applications such as distributed VPN services, high-resolution image, distributed database, and real-time video/audio service, generally require high-speed transmissions and usually exhibit traffic locality in WAN/LAN. Consequently, based on the traffic parameters such as locality and loading, an architecture named a 2TDMA (2-level TDMA) network is proposed. An analytical model is also presented and evaluated. The results of the analytical evaluations show that: 1) the performance of a network depends on the network loading, locality, and number of groups; 2) the increased traffic locality could increase the slot utilization and throughput; and 3) if the traffic locality is larger than a threshold, a 2TDMA network can generate higher throughput than a network with TDMA. Hence, if a system can be operated with appropriate loading, group, and traffic locality, its utilization and throughput will be enhanced significantly.