Practical traffic grooming scheme for single‐hub SONET/WDM rings

Article type: Research Article

Authors: Li, Xiang‐Yang | Liu, Liwu | Wan, Peng‐Jun | Frieder, Ophir

Affiliations: Department of Computer Science, Illinois Institute of Technology, Chicago, IL 60616, USA E‐mail: {xli, liwuliu, wan, ophir}@cs.iit.edu

Abstract: In SONET/WDM networks, one fiber supports multiple wavelengths and each wavelength supports several low rate tributary streams. ‘Traffic grooming’ then is defined as properly using SONET Add/Drop Multiplexer to electronically multiplex and demultiplex required tributary traffic patterns with minimal resource cost (wavelengths and ADMs). This paper studies traffic grooming problem in single hub SONET/WDM networks and extends existing results. We analyze the real deployments, generalize their results, and study the practical special cases. We prove that BLSR/2 would never be more expensive than UPSR under any traffic pattern. We also present the exact minimum costs of uniform traffic in both UPSR and BLSR/2. We give approximation algorithms for optimal grooming of non‐uniform traffic. Finally, we consider how to select the line speeds if there are two different line speeds available.

Keywords: Traffic grooming, SONET/WDM ring, UPSR, BLSR/2, single‐hub, bin packing

Journal: Journal of High Speed Networks, vol. 11, no. 2, pp. 103-119, 2002