Scheduling on All-Optical Broadcast-Star WDM Networks with Restricted Tunable Wavelengths

• Main Authors: Ying-Tsung Chen, 陳瑩聰
• Other Authors: Sing-Ling Lee
• Format: Others
• Language: en_US
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/23418683099414667513

碩士 === 國立中正大學 === 資訊工程研究所 === 89 === In all-optical broadcast-star WDM networks with W wavelengths and N nodes, each node is equipped with one tunable transmitter with non-negligible tuning time and one fixed receiver. Furthermore, we assume that the amount of available tunable wavelengths in each node is restricted to a fixed value r which is less than W. Given an off-line uniform traffic matrix, the objective is to design a multi-hop scheduling algorithm to minimize the total transmission time slots. We first present an approach to partition the original star architectures into several rings for efficient packet transmission in later stage. We reduce the problem of choosing suitable rings to the set cover problem. As ra=(W-1)/2, we can find the optimal set cover if it exists. When the packets are transmitting in suitable logical topology ring, it is beneficial to shorten the propagation delay, and shorten total scheduling period. Finally, we show that the tuning time step is possible overlapped with packet transmission in the scheduling when the ratio of N/W is large.