Hcbs Hybrid Optical Switching Network Design,

As the development of science and technology, broadband communication networks have got gigantic development. But Government, finance community, telecoms as well as individual consumer's desire for computer network applications as well as Point-to-Point multi-media stream and IP-based real time service's striving are triggering dramatic growth of network traffic. Under this circumstance, traditional electric networks are no longer likely to bear this burden. Under this circumstance WDM based optical networks is becoming the main underlying transmission network. WDM based optical networks consist of optical circuit switching network(OCS) and the other two, OPS and OBS, whose full name are optical packet switching and optical burst switching. OCS networks are commonly used to carry flows who has long duration time and require low-latency while OPS and OBS are more suitable for bursty flows. But OPS can't be put into large-scale commercial use right now, while OBS have performance defects such as high burst loss rate, latency. In view of this, researchers have come up with the idea of combining different switching techniques to form hybrid optical networks.The first chapter give an brief introduction of the current hybrid optical networks, namely master-slave, parallel and integrated hybrid optical networks. We analyse their network architecture, node function, packet forwarding process and pointed out each's disadvantage. In the end, we made a comparison of the three and give a conclusion.We presents a new OCS/OBS hybrid optical switching network (HCBS) in chapter two, The OCS layer of the proposed network is composed of light paths which are established according to the traffic demands between all the source-destination nodes. And the remaining wavelength channels on each physical link are used to build the OBS layer. When one or more light path break down due to network failure(s), the affected data packets could be assembled into bursts and transported through the OBS layer. In normal operating scenario, OCS layer carries most of the traffic. If bursty traffic overwhelms the transmission capacity of OCS layer, the excess part of traffic could be sent through OBS. So the main idea of HCBS is to use OBS layer as a protection layer of OCS and a layer to deal with network flow's burst. In order to validate the feasibility and efficiency of HCBS, we build up a software platform based on OPNET, which is a commonly used tool for addressing network planning,engineering, R&D. During the validation process, we compare HCBS with proteced OCS network, single layer OBS network from packet lost rate, latency and ability to combat mulitple failures. Simulation results show that, compared with the pure OCS network with restoration and pure OBS network, the proposed hybrid optical switching network could achieve lower packet loss rate under different network failure scenarios and could accommodate bursty data streams more efficiently.In chapter four, we further devleop HCBS from two aspects. By using the ieda of mulitple topology routing, OBS layer fast recovery scheme and OBS layer traffic engineering scheme are put forward and specified. In chapter five, the two proposed schemes are simulated on the platform we former build and analysis of the result are given. Chapter six introduce our simulation platform and the last chapter is the conclusion of this dissertation.