A Carrier-Preview Multiple Channel Slotted Ring for All-Optical Networks
| Autor: | Jun-Yao Wang, 王俊堯 |
|---|---|
| Rok vydání: | 2000 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 89 This thesis presents a high performance Carrier-Preview protocol for WDM multi-channel slotted ring networks with a single tunable transmitter and fixed receiver. The proposed protocol can utilize the bandwidth of optical networks efficiently and reduces the implementation complexities that constrain other related protocols such as the global synchronization requirement of the SRR [3]. The Carrier-Preview capability of the protocol allows every node to inspect the status of all channels at the next slot time. According to the status information, a source node can select an appropriate channel for transmitting packets from among the free channels through appropriate selection schemes. This study also proposes and evaluates two selection schemes. Using a control channel, the Carrier-Preview capability is achieved by broadcasting the previewed status information carried in control packets. In addition, to resolve the fairness problem that is frequently encountered in ring-type networks, a fairness mechanism based on the Multi-MetaRing protocol is used to provide fair access to the network between nodes. Besides the proposed protocol, in this thesis, we also propose some analytical models for the multi-channel slotted ring networks with different transmission protocols. In order to analyze the multi-channel slotted ring networks with a single tunable transmitter and fixed receiver, we adopts some queuing models to approximate the packet delay of the networks. In the thesis, two transmission protocols of multi-channel slotted ring networks are analyzed, that are the RND protocol and the CPMR protocol with the RS strategy. For the RND protocol, we present a non-preemptive priority queue model to approximate the packet delay of the protocol. The behavior of the protocol is translated to the proposed non-preemptive priority queue model. With this model, the analytical packet-delay approximations can be obtained by close-form formulas. For the CPMR protocol with the RS strategy, we adopt the M/G/1 queuing model to match the behavior of the protocol. The packet-delay analytical results of every queue in the protocol can be modeled by the M/G/1 model. The similarity between the two analyses is that they are based on the concept of the selected interval described in the thesis. In the final part of this thesis, simulation results demonstrate that the CPMR protocol can achieve nearly optimal channel utilization under balanced traffic. Moreover, the incorporation of the fairness mechanism also reveals excellent throughputs. For the analytical results, the accuracy of the model for the RND protocol is assessed using the simulation results. In addition, simulation results also verify that the M/G/1 model can model the behavior of the CPMR protocol with the RS strategy. However, the results of the analytical model can be detected the deviations from the simulative results. It will be required more sophisticated adjustments from some approximated equations. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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