A large number of network applications today allow several users to interact together using the many-to-many service mode. In many-to-many communication, also referred to as group communication, a session consists of a group of users (we refer to them as members), where each member transmits its traffic to all other members in the same group. In this paper, we address the problem of grooming subwavelength many-to-many traffic (e.g., OC-3) into high-bandwidth wavelength channels (e.g., OC-192) in optical wavelength division multiplexing (WDM) mesh networks. The cost of an optical WDM network is dominated by the cost of higher-layer electronic ports (i.e., transceivers). A transceiver is needed for each initiation and termination of a lightpath. Therefore, our objective is to minimize the total number of lightpaths established. Unfortunately, the grooming problem even with unicast traffic has been shown to be NP-hard. In this paper, we introduce two novel approximation algorithms for the many-to-many traffic grooming problem. We also consider the routing and wavelength assignment problem with the objective of minimizing the number of wavelengths used. Through extensive experiments, we show that the proposed algorithms use a number of lightpaths that is very close to that of a derived lower bound. Also, we compare the two algorithms on other important objectives such as the number of logical hops traversed by a traffic stream, total amount of electronic switching at a node, and Min-Max objectives.

A large number of network applications today allow several users to interact together using the many-to-many service mode. In many-to-many communication, a session consists of a group of users (we refer to them as members), where each member transmits its traffic to all other members in the same group. In this paper, we address the problem of dynamic provisioning of optical WDM networks to support many-to-many traffic grooming. The objective is to minimize the overall blocking probability of arriving many-to-many sessions. We address the problem in both non-splitting networks where the nodes do not have optical splitting capabilities and in splitting networks where the nodes have optical splitting capabilities. In each of the two networks, we propose a number of dynamic provisioning heuristics and we provide extensive experiments to evaluate and compare their performance.

A large number of network applications today allow several users to interact together using the many-to-many service mode. In many-to-many communication, also referred to as group communication, a session consists of a group of users (we refer to them as members), where each member transmits its traffic to all other members in the same group. In this paper, we address the problem of grooming sub-wavelength many-to-many traffic (e.g., OC-3) into high-bandwidth wavelength channels (e.g., OC-192) in WDM mesh networks. The cost of a WDM network is dominated by the cost of higher layer electronic ports (i.e., transceivers). A transceiver is needed for each initiation and termination of a lightpath. Therefore, our objective is to minimize the total number of lightpaths established. Unfortunately, the grooming problem even with unicast traffic has been shown to be NP-hard. For a number of special cases where the many-to-many traffic grooming problem is tractable, we efficiently derive the optimal solution, while in the general case, we introduce two novel approximation algorithms. We also consider the routing and wavelength assignment problem with the objective of minimizing the number of wavelengths used. Through extensive experiments, we show that the two algorithms use a number of lightpaths that is very close to that of a derived lower bound. Also, we compare the two algorithms on the several costs mentioned in the paper including the number of lightpaths and the number of wavelengths used.

A large number of network applications today allow several users to interact together using the many-to-many service mode. In many-to-many communication, also referred to as group communication, a session consists of a group of users (we refer to them as members), where each member transmits its traffic to all other members in the same group. In this paper, we address the problem of designing and provisioning of WDM networks to support many-to-many traffic grooming. Our objective is to minimize the overall network cost, which is dominated by the cost of higher layer electronic ports (i.e., transceivers) and the number of wavelengths used. Based on different WDM node architectures, we propose four different WDM networks for many-to-many traffic grooming. For each network, we analyze the many-to-many traffic grooming problem and provide an optimal as well as a heuristic solution. A comprehensive comparison between the four networks reveals that each of the networks is the most cost-effective choice for a certain range of traffic granularities.

A large number of network applications today allow several users to interact together using the many-to-many service mode. A many-to-many session consists of group of users (we refer to them as members), where each member transmits its traffic to all other members in the same group. We address the problem of designing and provisioning of WDM networks to support many-to-many traffic grooming. Our objective is to minimize the overall network cost which is dominated by the cost of transceivers and the number of wavelengths used. We consider three different WDM networks for this problem. One is the non-splitting network, where the nodes do not support optical splitting. The other two networks are the hubbed and the all-optical networks, where the nodes support optical splitting. In the hubbed network, all members in a session transmit their traffic to a designated hub node. Using the new technique of network coding, the hub then linearly combines the traffic units received and sends back to the members a set of linear combinations using light-tree(s). In the all-optical network, each member in a session transmits its traffic directly to all other members in the same session using a light-tree. A comprehensive comparison between the three networks reveals that each of the networks is a cost-effective choice for a certain range of traffic granularities.

In many-to-many communication, a session consists of group of users (we call them members) where each one of the members transmits its traffic to all other members in the group. This paper studies the problem of provisioning many- to-many sessions with sub-wavelength granularities in WDM mesh networks. Our objective is to minimize the number of transceivers required. We study the problem in networks with and without optical splitting capabilities. For networks without optical splitting capabilities, we use an optimal approach which is an extension of that introduced in [8] for the many-to-one traffic grooming problem. For networks with optical splitting capabilities, we introduce a novel hub-based approach where each session is routed through a many-to-one tree from the members to a central hub node, and then through a multicast tree from the hub node back to the members. At the hub node, network coding is performed by linearly combining the traffic units received from the members. These combinations are then groomed and delivered back to the members using light-tree(s). Numerical results from both approaches are presented and compared.