Ph.D. Preliminary Exam - Taiming Feng

Date: 30 Oct, 2009
Time: 8:00 AM
Location: 223 Atanasoff Hall
Topic: Survivability Schemes for Optical Networks
Major Professor(s): Lu Ruan


Abstract:

Network survivability is an important requirement for WDM optical networks due to their ultra-high capacity. Although single-link failures are the most common failure scenarios, double-link failure can occur in some cases. Thus we first consider the problem of protecting unicast connections against two simultaneous link failures. The basic idea is to use two p-Cycles with link-disjoint protection segments to protect each working link. Compared to unicast sessions, multicast sessions suffer more seriously from link failures because a link may carry traffic to multiple destinations rather than to a single destination. Hence, multicast sessions demand more effective and efficient protection against link failures. In this report, we propose an intelligent p-Cycle (IpC) scheme to provide p-Cycle protection for dynamic multicast sessions. When a multicast request arrives, a multicast tree is computed for it (using any known algorithm) and then the IpC scheme is used to compute a set of high efficiency p-Cycles on-demand to protect the multicast tree. In addition to survivability schemes in backbone networks, we also propose a new protection scheme for the hybrid wireless-optical broadband-access network(WOBAN). The scheme is cost-effective in that it does not require the PONs to have self-protecting capability. Based on the proposed protection scheme, we define the maximum protection with minimum cost (MPMC) problem and present a solution approach to the MPMC problem. Finally, we outline the plan for future research directions and then conclude the report.