Multicasting algorithm in multimedia communication network

Internet services provider propose increasingly numerous applications depend on multicast communication patterns, such as database synchronization, newsletter updates, video, and audio group streaming. In spite of, IP multicast is frequently suffered from scaling and instability, which causes internet provider administrators to avoid its utilization. While different multicast protocols in all layers, such as routing and switching, have been created by researchers and providers, through several years, to focus on security, congestion control, and scalability, our work aims to scale multicast regarding the number of supported multicast groups and sources in networks and multicast session. In this paper, we propose an SDN-based IP multicast tree construction module to support and deploy multicast communication-based services. To do so, we take advantage to compute multicast tree, in the centralized way, to achieve a dynamic tree construction algorithm that helps SDN controller to dynamically construct and adjust an optimal multicast tree in all multicast session. The experiments studies on the prototype and simulation system exhibit that our solution gives better performance contrasted with the traditional multicast tree construction algorithms, better also to SDN-based solution proposed in the literature, regarding multicast tree cost, delay, delay variation, and multicast tree construction delay.

With the proliferation of multimedia group applications, the construction of multicast trees satisfying quality of service (QoS) requirements is becoming a problem of prime importance. Many of the multicast applications (such as video broadcasts and teleconferencing) require the network to support dynamic multicast sessions wherein the membership of the multicast group changes with time. We propose and evaluate an algorithm for on-line update of multicast trees to adjust to changes in group membership. The algorithm is based on a concept called quality factor (QF) that represents the usefulness of a portion of the multicast tree to the overall multicast session. When the usefulness of a particular region of the tree drops below a threshold, a rearrangement technique is used to suitably modify the tree. This algorithm aims to satisfy the delay-constraints of all current group members, at the same time minimizing the cost of the constructed tree. We compare the performance of our algorithm, by simulation, with that of an off-fine Steiner heuristic; with ARIES, a previously published algorithm for on-line update of unconstrained trees; and with the algorithm proposed by Hong, Lee and Park (see Proc. of IEEE INFOCOM, pp. 1433-40, 1998) for on-line update of delay-constrained trees. The simulation results indicate that our algorithm provides excellent cost-competitiveness that is better than that provided by the algorithm described by Hong et al., minimizes changes in the multicast tree after each update, and performs favorably even when compared with the unconstrained ARIES heuristic.

With the proliferation of multimedia group applications, the construction of multicast trees satisfying quality of service (QoS) requirements is becoming a problem of prime importance. Many of the multicast applications (such as video broadcasts and teleconferencing) require the network to support dynamic multicast sessions wherein the membership of the multicast group changes with time. In this paper, we propose and evaluate an algorithm called CRCDM (controlled rearrangement for constrained dynamic multicasting) for on-line update of multicast trees to adjust to changes in group membership. The CRCDM algorithm is based on a concept called quality factor (QF) that represents the usefulness of a portion of the multicast tree to the overall multicast session. When the usefulness of a particular region of the tree drops below a threshold, a rearrangement technique is used to suitably modify the tree. Our algorithm aims to satisfy the delay constraints of all current group members, at the same time minimizing the cost of the constructed tree. We compare the performance of our algorithm, by simulation, with that of an off-line Steiner heuristic; with ARIES, a previously published algorithm for on-line update of unconstrained trees; and with the algorithm proposed by Hong, Lee and Park (see Proc. IEEE INFOCOM, p.1433-40, 1998) for on-line update of delay-constrained trees. The simulation results indicate that our algorithm provides excellent cost-competitiveness that is better than that provided by the algorithm described by Hong et al., minimizes changes in the multicast tree after each update, and performs favorably even when compared with the unconstrained ARIES heuristic.

This paper is concerned with a restricted version of minimum cost delay-constrained multicast in a network where each link has a delay and a cost. Given a source vertex $s$ and $p$ destination vertices $t_1, t_2, \ldots, t_p$ together with $p$ corresponding nonnegative delay constraints $d_1, d_2, \ldots, d_p$, many QoS multicast problems seek a minimum cost multicast tree in which the delay along the unique $s$--$t_i$ path is no more than $d_i$ for $1 \le i \le p$. This problem is NP-hard even when the topology of the multicast tree is fixed. In this paper we show that every multicast tree has an underlying Steiner topology and that every minimum cost delay-constrained multicast tree corresponds to a minimum cost delay-constrained realization of a corresponding Steiner topology. We present a fully polynomial time approximation scheme for computing a minimum cost delay-constrained multicast tree under a Steiner topology. We also present computational results of a preliminary implementation to illustrate the effectiveness of our algorithm and discuss its applications.

This article presents a new heuristic algorithm called DDBMA lDynamic Delay Bounded Multicast Algorithmr to construct a minimum-cost multicast tree. The heuristic depends on l1r bounded delay along paths from source nodes to destination node; l2r minimum cost of the multicast tree; l3r dynamic multicast tree status which is maintained by updating the existing multicast tree when nodes in the network request to join or leave. Copyright © 1999 John Wiley & Sons, Ltd.

A new heuristic algorithm is presented for constructing minimum-cost multicast trees with delay constraints. The new algorithm can set variable delay bounds on destinations and handles two variants of the network cost optimization goal: one minimizing the total cost (total bandwidth utilization) of the tree, and another minimizing the maximal link cost (the most congested link). Instead of the single-pass tree construction approach used in most previous heuristics, the new algorithm is based on a feasible search optimization method which starts with the minimum-delay tree and monotonically decreases the cost by iterative improvement of the delay-bounded tree. The optimality of the costs of the delay-bounded trees obtained with the new algorithm is analyzed by simulation. Depending on how tight the delay bounds are, the costs of the multicast trees obtained with the new algorithm are shown to be very close to the costs of the trees obtained by the Kou, Markowsky and Berman's algorithm (1981).

This paper proposes a tabu search (TS) based optimization approach to search a minimum-interference multicast tree which satisfies the end-to-end delay constraint and optimizes the usage of the scarce radio network resource in wireless mesh networks. The path-oriented encoding method is adopted and each candidate solution is represented by a tree data structure (i.e., a set of paths). Since we expect the multicast trees on which the minimum-interference channel assignment can be produced, a fitness function that returns the total channel conflict is devised. The techniques for controlling the tabu search procedure are well developed. A simple yet effective channel assignment algorithm is proposed to reduce the channel conflict. Simulation results show that the proposed TS multicast algorithm can produce the multicast trees which have better performance in terms of both the total channel conflict and the tree cost than that of a well known multicast algorithm in wireless mesh networks.

For many multimedia multicast applications, especially those requiring real-time traffic, it is important that the maximum delay bound requirement between any pair of group members be satisfied. Most studies on multicast routing have been based on a single multicast tree (a shortest path tree or a minimal Steiner tree) approach. By using only a single multicast tree for a multicast group, satisfying the maximum delay bound requirement is nearly impossible. To fulfill these requirement, we adopt the multiple multicast tree concept whose disadvantage is the high tree maintenance cost. Since the tree maintenance cost is proportional to the number of multicast trees for a multicast group, it is necessary to minimize the number of multicast trees. In this paper, we formulate the delay-bounded multicast tree (DBMT) problem whose main objectives are to satisfy an application's maximum delay bound among the group members and to minimize the number of multicast trees needed for a group communication. We categorize the DBMT problem according applications' needs into two subproblems, the shortest path tree-based DBMT (SPT DBMT) and the minimal Steiner tree-based DBMT (MST DBMT) problems. For the DBMT subproblems, we prove the NP-hardness and propose heuristic algorithms. For the performance analysis, simulations were performed.

With the growing demand of multimedia applications, quality of service (QoS) assured that multicast routing is an important issue in wireless mesh networks. Finding a multicast tree which satisfies the multiple constraints is a NP-Complete problem. In this paper, we propose a discrete particle swarm optimization (DPSO) approach for finding the minimum tree cost from a given source to a set of destination with delay and bandwidth constraint. The concept of relative position base indexing (RPI) is used to convert a continuous space to discrete space for multicast routing. The simulation is carried out in NS-2.26 and the comparison is made with respect to tree cost under two scenarios, namely varying node mobility and increasing number of nodes. The results demonstrate that DPSO has better speed, performance, and efficiency than multicast routing based on genetic algorithm.

A critical requirement for multi-party multimedia applications is to generate a multicast tree that has minimal overall network cost and acceptable end-to-end network delay in every path. These two features of the multicast tree are often conflicting in nature and the problem of minimizing the overall network cost in multicast routing is a Steiner tree problem which is known to be NP-complete. Most of the multicasting algorithms use heuristics that will optimize either the cost or the delay; however, the requirements of real-time multimedia applications cannot be satisfied. In this paper, a path selection function taking both the cost and the delay into consideration is proposed. A performance study is carried out by applying the path selection function to existing multicasting algorithms. Our results show that by simply changing the path selection function, the overall cost of the multicast tree can be reduced significantly while satisfying the real-time constraint of the multimedia applications.

In this paper, we introduce algorithms for constructing broadcasting and multicasting trees. These algorithms are general because they may be used for tree cost functions that are of arbitrary form. Thus, essentially the same algorithmic procedures are used for different tree cost functions. We evaluate the effectiveness of the general algorithms by applying them to different cost functions that are often used to model wired and wireless networks. Besides providing a unifying framework for dealing with many present and future tree-construction applications, these algorithms typically outperform some existing algorithms that are specifically designed for energy-aware wireless networks. These general algorithms perform well at the expense of higher computational complexity. They are centralized algorithms, requiring the full network information for tree construction. Thus, we also present variations of these general algorithms to yield other algorithms that have lower complexity and distributed implementation.

The basis of multicast data transmission is to construct a multicast tree. The main problem concerning the construction of a multicast tree is the selection of the root of the shared tree or the core point. Therefore, the algorithm we propose guarantees that the delay from the source to any destination does not exceed a real-time constraint satisfying the delay-variation constraint under cost minimization. The core selection function in this algorithm achieves a balance of optimizing cost and delay of the multicast tree. Simulation results show that the algorithm has low complexity and balances between the computational complexity and performance.

Multicast group communication has many advantages in data centers and thus is widely used by many applications. It can efficiently reduce the network traffic and improve the application throughput. For the multicast application in data centers, an essential problem is how to find a minimal multicast tree, which has been proved to be NP-hard. In this paper, we propose an approximation tree-building method for the minimal multicast problem, named HD （Hamming Distance）-based multicast tree. Consider that many new network structures have been proposed for data centers. We choose three representative ones, including BCube, FBFLY, and HyperX, whose topological structures can be regarded as the generalized hypercube. Given a multicast group in BCube, the HD-based method can jointly schedule the path from each of receiver to the only sender among multiple disjoint paths; hence, it can quickly construct an efficient multicast tree with the low cost. The experimental results demonstrate that our method consumes less time to construct an efficient multicast tree, while considerably reduces the cost of the multicast tree compared to the representative methods. Our approach for BCube can also be adapted to other generalized hypercube network structures for data centers after minimal modifications.

The geographically distributed system can be interconnected via an overlay multicast network. In this overlay network the multicast data are routed and replicated on the application layer along a multicast tree. This paper presents the techniques of the network reduction and the multicast tree construction. The multicast tree in the form of shortest path tree (SPT) can be build up upon the linear programming formulation. To control the load of each host, the additional constraints on the maximal number of directly outgoing connections and integer variables are added and subsequently form the degree-bounded shortest path tree problem (db-SPT). This theoretically based problem is formulated in integer linear programming framework

In a communication network with a source node, a multicast tree is defined as a tree rooted at the source node and all its leaves being recipients of the multicast originating at the source. The tree or bandwidth cost is normally measured by its utilization of tree links along with the quality of service (QoS) measures such as delay constraint and end-to-end delay. However, if nodes are allowed to join or leave the multicast group at any time during the lifetime of the multicast connection, then the problem is known as dynamic multicast routing problem. In this article, we combine a greedy approach with static multicast routing using Tabu Search to find a low-cost dynamic multicast tree with desirable QoS parameters. The proposed algorithm is then compared with several static multicast routing algorithms. The simulation results show that, on a large number of events, i.e., where nodes are leaving or joining, the proposed algorithm is able to find multicast trees of lower cost and more desirable QoS properties.