Research On TWT Photonic Burst Network Architecture And Its QoS Control

With the rapid development of Internet and communication technologies, a lot of new services have emerged, especially the IP applications, which result in the dramatic Internet traffic increase. Traditional services such as telephone service have been changed to IP based multimedia applications such as video conferencing, video on demand and so on, which require the communication networks to provide higher transmission speed, larger capacity and better quality of service.Because of the large potential bandwidth of fiber and the fast development of WDM system, nowadays the optical communication has become one of the key technologies for communication networks. All optical packet switching networks are still in their experimental stage because we lack optical random access memory and mature all optical processing technologies nowadays. Although optical circuit switching technology is commercially available, the bandwidth utilization is low, especially in the case of bursty traffic condition. Optical burst switching technology is promising because it can combine the advantages of both optical packet switching and optical circuit switching, but it has its own problems such as high burst loss rate, high burst contention and so on, so it is still in the lab level.Considering the current development of optical device technologies and the network interconnection schemes, this thesis presents a novel national transport network architecture which combines the Optical Time Division Multiplexing (OTDM) and Optical Wavelength Division Multiplexing (OWDM) technologies. We call it TWT photonic burst network because it employs OTDM in the regional network and OWDM in the long haul backbone network. In TWT photonic burst network, the bandwidth granularity is a single timeslot rather than a whole wavelength, so the bandwidth can be used more efficiently; what is more, the dynamic bandwidth allocation is based on the reservation information of every edge node, so it can meet the challenge of burtsy IP traffic.It is well known that Internet can only provide best-effort service. In this way, all traffic flows are treated fairly and they contend for the same network resources, so the expected QoS only depends on the current traffic load of the link. However with the commercialization of Internet, there are many new applications which have very different QoS requirements, so there should be different levels of network service to...