A Media-Access Protocol for WDM Star-Coupler Networks with Variable-Length Transmission

• Main Authors: Chin Hsi Chien, 秦錫堅
• Other Authors: H.-L Chen
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/02262074385361730506

碩士 === 國立臺灣科技大學 === 電子工程學系 === 84 === In an optical star coupler network, all stations are connec- ted via a passive star coupler. Wavelength division Multiplexing (WDM) technology has be used to increase the total bandwidth. WDM is defined to divide the optical bandwidth of the fiber into different wavelength channels. Two moduses, single-hop and multi-hop, are explored in WDM lightwave networks. In the multi- hop modus, their data packets need to go through zero or more intermediate nodes before reaching destinations, while data packets are sent from their sources directly to their destinations in the single-hop modus. The media access protocol is used to schedule data transmissions on multiple channels for the single-hop modus. This paper proposes a media-access scheme for single-hop modus in all-optical local networks. The network architecture is called CC-FTTT-FRFR, in which each station is equipped with a fixed-tuned transmitter, a tunable transmitter and two fixed- tuned receivers. We combine the time division multiplexing (TDM) and dynamic allocation scheme (DAS), and allow that packet sizes are variable. Two scheduling algorithms provide lower message delay for small and variable-size messages. First algorithm is called Variable-Length Dynamic Allocation Scheme (VLSDAS), in which tuning time is not considered for transmitters. Second algorithm is called Variable-Length Dynamic Allocation Scheme with Tuning Delay (VLDASTD), in which tuning time is considered for transmitters. We conduct the simulations for these protocols in terms of average message delay. Results indicate that these protocols exhibit lower average message delay under small and variable-size message transmissions.