Wavelength assignment in fixed routing WDM networks

Abstract

am 1) epar t men t of Electrical Engineering 1J 11 i ve r s i t y of Was hi 11 g t on Seattle, WA 98195 AbstractWe propose a new algorithrn for the dynamic centralized wavelength assignment problem in fixed-routing WDM networks without wavelength conversion. The blocking perforiiiance of our algorithiii is better in many cases (and no worse in the cases we studied) than other previously proposed algo rat hiiis. The perform an ce am proveinent of our algorithm over other algorithins i s high for multi-fiber ring networks with a moderate number of fibers per link. In a multi-fiber mesh-torus network, the difference in performance is not as significant, but the blocking probabilities for all algorithms approach those achievable b y wavelength conversion as the number of fibers per link increases. We also extend an earl i w analytical model for predicting the blocking probability with and tuzthout wavelength conversion t o dense multi-fiber networks. Finally, our siiriulation results on multi-fiber rings and inesh-tort reveal surprising results about the benefits of wavelcngth conversion as the number of fibers per link incrpases.

A generalized framework for analyzing time-space switched optical networks

“…Wavelength assignment in networks employing fixed-path routing has been analyzed in [28]. Routing in networks with more than one candidate path has been shown to offer signilicant performance improvement [29].…”

Traffic grooming and wavelength conversion in optical networks

“…A number of different routing and wavelength assignment approaches have been investigated in the literature. With respect to the traffic demand, there are two variations of the problem: (a) static or off-line traffic in which the set of traffic stream requests are given of wavelengths used [14], [15] and (b) dynamic or online in which traffic stream requests arrive and depart randomly [16], [17], [25]. Routing algorithms can be classified as either static or adaptive.…”

“…Fixed-paths least-congestion routing has been analyzed in [22]. Dynamic Wavelength Assignment (D-WA) algorithms, such as first-fit (FF) [15], random assignment (R) [19], most-used (MU) [17], Max-Sum (MS) [16] and Relative Capacity Loss (RCL) [25] have also been proposed. For a review of routing and wavelength assignment approaches in WDM networks, refer to [26].…”

“…Current Dynamic Wavelength Assignment (D-WA) al gorithms, such as first-fit (FF) [15], random assignment (R) [19], most-used (MU) [17] and MaxSum (MS) [16], were designed in a network scenario where the full wavelength was the basic unit of bandwidth. However, in WDM networks capable of traffic grooming, the basic unit of bandwidth is a traffic stream whose capacity can be less than that of a wavelength.…”

Collaborative User-Centric Lambda-Grid over Wavelength-Routed Network

“…RWA schemes can either be decoupled if the sub-problems are solved independently, or coupled if the sub-problems are solved in a coupled way. Coupled RWA schemes would perform better but incurs greater computational complexity than that of decoupled RWA schemes, which include fixed-RWA [14] with a single precalculated route for each source-destination pair, and dynamic-RWA [15][16] with dynamic calculated routes based on current topology information of link state.…”