Design and analysis of optical packet switching systems with multicast capability
Date of Issue2011
School of Electrical and Electronic Engineering
Optical fiber communication has developed so rapidly during the last decades that it has become the backbone of today’s communication systems. To take advantage of the huge bandwidth of optical fiber links, optical packet switching systems have been proposed and investigated intensively. However, most of the existing optical packet switches cannot effectively support multicast applications. To address this problem, this thesis is performed with objectives of design and analysis of optical packet switching systems with multicast capability. A wavelength-routed multicast packet switch utilizing multicast modules is proposed and investigated. By means of the multicast modules, the switch allows copies of a multicast packet to be made in multiple timeslots to reduce packet contention and then to be switched to desired outputs. Furthermore, a packet scheduling technique is designed for contention resolution for the proposed switch. Performance evaluation is carried out to study the feasibility of the multicast switch. It is shown that the switch can achieve a low multicast packet loss probability with a few multicast modules. Furthermore, to enhance the multicast performance, an improved scheme is then presented by modifying the multicast modules in the switch. Investigation on traffic performance shows that the improved scheme can considerably reduce packet loss probability for the switch without adding more multicast modules. Nevertheless, it can only handle a small proportion of multicast traffic. To overcome the performance deterioration caused by a large volume of multicast traffic, a novel wavelength-routed multicast packet switch with a shared fiber delay lines (FDLs) buffer is then proposed. This switch allows both unicast and multicast packets to share a set of FDLs for buffering, and more importantly, a multicast packet can be replicated in multiple timeslots by multi-wavelength conversion in conjunction with the shared FDLs buffer. Traffic performance evaluation and complexity discussion show that the proposed switch can not only effectively reduce the performance deterioration caused by the increase of multicast traffic, but also exhibit much simpler configuration than other proposals for optical packet multicasting. A multi-wavelength broadcast-and-select packet switch and its multicast traffic performance are comprehensively investigated. The switch enables to concurrently transmit multiple optical packets to the same output fiber of the switch and employs a multi-timeslot replication scheme to reduce the multicast packet contention. An analytical model of the switch is developed for traffic performance investigation and then verified by simulation. Results show that with the multi-timeslot replication, the switch can achieve a much better traffic performance, which is unaffected by the multicast traffic ratio. Scalability analysis shows that the switch with more wavelengths per fiber can achieve a given packet loss probability at a lower power loss. Furthermore, an improved scheme is presented for reducing the number of amplifiers required by the switch for compensating the power loss.
DRNTU::Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics