Conference Paper

Multicast routing and wavelength assignment in WDM networks with limited drop-offs

Inst. of Appl. Math., Chinese Acad. of Sci., Beijing, China
DOI: 10.1109/INFCOM.2004.1354520 Conference: INFOCOM 2004. Twenty-third AnnualJoint Conference of the IEEE Computer and Communications Societies, Volume: 1
Source: DBLP


In WDM networks with limited drop-offs, the route of a multicast connection consists of a set of light-trees. Each of the light-tree is rooted at the source node and contains no more than a limited number, say k, destination nodes due to the power loss of dropping optical signals off at destination nodes. We call such a light-tree k-drop light-tree. In this paper we study the multicast routing problem of constructing a set of k-drop light-trees that have the minimal network cost. The network cost of a set of light-trees is defined as the summation of the link cost of all the light-trees. We first prove that this problem is polynomial-time solvable for k=2 and NP-hard for k≥3. We then propose a 4-approximation algorithm for the problem for k ≥3. A wavelength assignment algorithm is also proposed to assign wavelengths to the light-trees of a multicast connection. In the end we give simulation results showing that k-drop multitree muting can significantly save not only the network cost but also wavelengths used. Moreover, when k≥5 its performance is very close to the case where k is infinite (i.e., the case of using a single tree for a multicast connection).

Download full-text


Available from: Tianping Shuai, Aug 15, 2014
16 Reads
  • Source
    • "All the above approximation algorithms [1] [9] [10] [3] [6] [12] show that the total cost of a k-tree routing consists of two components: the weight of the initial infeasible solution subgraph (such as a Hamiltonian cycle or a Steiner tree) and the connection cost depending on the size range of the achieved routing trees using Eqs. (1.1) and (1.2). "
    [Show abstract] [Hide abstract]
    ABSTRACT: In the multicast k-tree routing problem, a data copy is sent from the source node to at most k destination nodes in every transmission. The goal is to minimize the total cost of sending data to all destination nodes, which is measured as the sum of the costs of all routing trees. This problem was formulated out of optical networking and has applications in general multicasting. Several approximation algorithms, with increasing performance, have been proposed in the last several years; the most recent ones rely heavily on a tree partitioning technique. In this paper, we present a further improved approximation algorithm along the line. The algorithm has a worst-case performance ratio of 54ρ+32, where ρ denotes the best approximation ratio for the Steiner minimum tree problem. The proofs of the technical routing lemmas also provide some insights into why such a performance ratio could be the best possible that one can get using this tree partitioning technique.
    Theoretical Computer Science 01/2011; 412(3):240-245. DOI:10.1016/j.tcs.2009.05.031 · 0.66 Impact Factor
  • Source
    • "The RoMR protocol (Robust Multicast Routing protocol) in [14] builds multiple reliable multicast trees that adapt to topology changes in a dynamic fashion. Studies in [15] [16] use multiple subtrees, each spanning the source node and some destination nodes to solve wavelength assignment in WDM networks. Different from the above schemes, our scheme simultaneously uses the multiple paths or trees, so that the aggregate bandwidth of them can meet the bandwidth requirement of a single QoS request when reaching a suboptimal goal of minimizing the network cost under the delay bound. "
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, we investigate the issues of QoS multicast routing in wireless ad hoc networks. Due to limited bandwidth of a wireless node, a QoS multicast call could often be blocked if there does not exist a single multicast tree that has the requested bandwidth, even though there is enough bandwidth in the system to support the call. In this paper, we propose a new multicast routing scheme by using multiple paths or multiple trees to meet the bandwidth requirement of a call. Three multicast routing strategies are studied, SPT (shortest path tree) based multiple-paths (SPTM), least cost tree based multiple-paths (LCTM) and multiple least cost trees (MLCT). The final routing tree(s) can meet the user’s QoS requirements such that the delay from the source to any destination node shall not exceed the required bound and the aggregate bandwidth of the paths or trees shall meet the bandwidth requirement of the call. Extensive simulations have been conducted to evaluate the performance of our three multicast routing strategies. The simulation results show that the new scheme improves the call success ratio and makes a better use of network resources.
    Ad Hoc Networks 07/2007; 5(5-5):600-612. DOI:10.1016/j.adhoc.2006.04.001 · 1.53 Impact Factor
  • Source
    • "However, wavelength conversion issues are not examined in [12]. Power loss in WDM networks is an important issue and, [13] and [14] examine multicasting from this perspective. Another static VTD formulation is given in [1], but the authors did not consider the sparse splitting cases. "
    [Show abstract] [Hide abstract]
    ABSTRACT: All-optical wavelength-routed WDM WANs can support the high bandwidth and the long session duration requirement of the application scenarios like interactive distance learning or online diagnosis of patients simultaneously in different hospitals. However, multifiber and limited sparse light splitting and wavelength conversion capabilities of switches result in a difficult optimization problem. We attack this problem using a layered graph model. The problem is defined as k edge-disjoint degree-constrained Steiner Tree problem for routing and fiber and wave-length assignment of k multicasts. A mixed integer linear programming formulation for the problem is given and a solution using CPLEX is provided. However, the complexity of the problem grows quickly with respect to the number of edges in the layered graph, which depends on the number of nodes, fibers, wavelengths, and multicast sessions. Hence, we propose two heuristics (LAMA and C-FWA) to compare with CPLEX, existing work and unicasting. Extensive computational experiments show that LAMA's performance is very close to CPLEX and it is significantly better than existing work and C-FWA for nearly all metrics. Although, C-FWA is inferior to LAMA it is also using fiber and wavelength conversion resources more efficiently than its other alternatives.
    Journal of Optical Networking 01/2007; 6(2). DOI:10.1364/JON.6.000219 · 1.08 Impact Factor
Show more