Performance of reservation access protocols for high-speed fiber optic networks

Abstract

The main objectives of this dissertation work are to propose access protocols based on reservation for high-speed fiber optic networks and to investigate the performances of the proposed protocols. As the speed of data transmission increases by using fiber optic technolgy, the ratio of the end-to-end signal propagation delay to the packet transmission time increases greatly. But, most existing network structures and access protoclos have the limit of the ratio in which they can operate normally. Therefore, it is necessary to develop network structures and access protocols which operate without regard to the variation of the ratio. With this purpose, we propose access protocols based on reservation for multiwavelength optical networks and fiber optic unidirectional bus networks, respectively. First, we propose access protocols using contention-based reservation schemes in a multiwavelength optical network with a passive star topology. A wavelength is used as a control channel and the others are used as data channels. To avoid multiple transmissions in the smae wavelength or to the same destination simultaneously, a reservation method is introduced. According to the length of data packets and the structrue of data channels, slotted and unslotted protocols are considered. And, according to the ratio of the end-to-end signal propagation delay to the transmission time of a data packet, basic and extended protocols are considered. Also, buffered and unbuffered protocols are considered according to the buffering of reservation at destination quesues. We analyze them by building a descrete-time Markov chain for the slotted protocol and a continuous-time Markov chain for the unslotted protocol. We obtain the system delay of data packets, the thruoghput per channel and the total system throughput. By numerical examples, we can observe that the delays for the proposed protocols remain small for a wide range of the system throughput. The basic reservation protocol has the ...