Enhanced Optimal and Heuristic Solutions of the Routing Problem in Light-Trail Networks

• Published in: Photonic network communications Vol. 15; no. 1; pp. 7 - 18
• Main Authors: Ayad, Amr S., Elsayed, Khaled M. F., Ahmed, Sanaa H.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-02-2008
• Subjects: Characterization and Evaluation of Materials; Computer Communication Networks; Computer Science; Electrical Engineering; All-optical networks; Traffic grooming; Heuristic solution; IP over optical; ILP; Light-trails
• ISSN: 1387-974X; 1572-8188
• DOI: 10.1007/s11107-007-0080-3

Light-trail is an efficient and feasible technology for IP transport over all-optical networks. The proposition of light-trails for all-optical networks has demonstrated a number of advantages over other paradigms such as Wavelength Routing (WR), Optical Burst Switching (OBS) and Optical Packet Switching (OPS). This article tackles the routing problem of light-trails with the solution objective of minimizing the number of needed light-trails to accommodate an offered traffic matrix. We present two enhancements to the Integer Linear Programming (ILP) formulation of the routing problem. We also propose a computationally efficient routing heuristic for use with static and incremental traffic models. The heuristic is based on routing flows one-by-one. This is done by assigning a set of attributes to each flow and to each network path. The flow attributes are used to determine the order in which flows are presented to the routing algorithm. The path attributes are used to determine which path is selected to route the flow at hand. The efficiency of the proposed heuristic is confirmed using example problems of different network topologies.