Search

For reliable multicasting, packet retransmission is an important mechanism in ensuring lossless data delivery. Existing packet retransmission methods cannot effectively address the recovery redundancy problem. This paper presents an OpenFlow-enabled elastic loss recovery solution, called ECast, for reliable multicasting. It employs a novel communication method, called elastic area multicast (EAM), to better retransmit the multicast recovery packets in OpenFlow-enabled networks. With the flexible flow-matching ability of OpenFlow switches, any subtree of a multicast tree can be used as an EAM tree. EAM approximately implements an elastic local multicast. Therefore, it can effectively alleviate the recovery redundancy with good scalability. We introduce an optimal EAM-based packet retransmission orchestration problem, named outdegree-constrained minimum-cost loss recovery (OCMCLR), which finds the EAM-based packet retransmission scheme with the minimum recovery cost. ECast uses an optimized tree-based feedback method to obtain the status of packet losses, and uses a fast cluster-based algorithm to approximately solve the OCMCLR problem based on the collected packet loss status.

Networking plays a crucial role in cloud computing especially in an inter-cloud environment, where data communications among data centers located at different geographical sites form the foundation of inter-cloud federation. Data transmissions required for inter-cloud federation in the complex inter-cloud networking system are often point-to-multi points, which calls for a more effective and efficient multicast routing algorithm in complex networking systems. In this paper, we investigate the multicast routing problem in the inter-cloud context with K constraints where K U+2265 2. Unlike most of existing algorithms that are too complex to be applied in practical scenarios, a novel and fast algorithm for establishing multicast routing tree for interclouds is proposed. The proposed algorithm leverages an entropybased process to aggregate all weights into a comprehensive metric, and then uses it to search a multicast tree U+0028 MT U+0029 on the basis of the shortest path tree U+0028 SPT U+0029.We conduct complexity analysis and extensive simulations for the proposed algorithm from the approximation perspective. Both analytical and experimental results demonstrate that the algorithm is more efficient than a representative multi-constrained multicast routing algorithm in terms of both speed and accuracy, and thus we believe that the proposed algorithm is applicable to the inter-cloud environment.

Due to significant advances in wireless modulation technologies, some MAC standards such as 802.11a, 802.11b, and 802.11g can operate with multiple data rates for QoS-constrained multimedia communication to utilize the limited resources of MANETs more efficiently. In this paper, by means of measuring the busy/idle ratio of the shared radio channel, a method for estimating one-hop delay is first suggested. Then, by constructing a multicast tree, a delay-sensitive multicast protocol for real-time applications in multirate MANETs is proposed. In order to increase the network capacity, the proposed multicast protocol intends to minimize the sum of the total transmission time of the forwarders and the total blocking time of the blocked hosts, by taking the neighboring information of the forwarders into account and properly adjusting the data rates of the forwarders. Simulation results show that the proposed delay estimation method is more accurate, as compared with previous works. Besides, the proposed multicast protocol can induce higher network capacity, while satisfying the delay requirement.

Multicasting can reduce network traffic in multiuser systems by serving multiple users simultaneously. The benefits of multicasting basically come from the overlapping and synchronism of user requests. Pushing and caching are techniques that prestore content items in buffers closer to users based on the prediction of user requests, thereby providing a promising approach to eliminating the asynchronism of user requests and creating multicasting opportunities. This paper studies a multiuser wireless communication system, in which the buffers for caching are deployed in the user terminals. Based on the request delay information (RDI) which describes when the users request content items in a deterministic or statistical way, a joint pushing and caching (JPC) method is presented to schedule the content items pushed by the base station and cached in the user buffers. In this paper, multicasting JPC systems work in two modes, without or with the feedback of RDI. Furthermore, RDI is classified into three forms, namely, noncausal, statistical, and causal. Static and dynamic JPC policies are, respectively, proposed for the two work modes. In addition, the effective throughput resulting from JPC under the three forms of RDI is demonstrated via theoretical analysis and simulation.

To support the massive content delivery, a novel virtualized heterogeneous network framework is proposed to enable content transcoding, caching, and multicast. In addition, a virtual multi-resources allocation problem is formulated to jointly optimize the utilities of computing, caching, and communication for the proposed framework. Simulations are conducted to show the effectiveness of the proposed scheme.

Wireless mesh networks (WMNs) connect to the Internet via access gateways. This paper studies multi-source video multicast in Internet-connected WMNs. The focus is on the design of a shareable integrated multicast that allows the multicasts of video sources to employ common Internet shortcuts or WMN paths to avoid potentially high WMN overheads and excessive Internet usage. Several algorithms are described that together form a video multicast framework running a controlled number of shareable multicasts under the constraint of Internet availability. These algorithms are the resource-efficient source group algorithm, the efficient integrated architecture algorithm, and the interference-controlled multicasting tree algorithm. These algorithms represent different approaches to overcoming various costs arising from multi-source video multicast, enabling multiple video sources to distribute delay, and throughput-guaranteed videos to receivers across large-scale areas. Simulation results are presented that quantify the performance gains that can be achieved.

It is a quite common case for Wireless Sensor Networks (WSNs) in most application scenarios, that the same message needs to be sent to multiple destinations from a single sensor node. These applications can benefit from the use of multicast communications to conserve resource. Multicast geographic routing has recently been proposed as an efficient and scalable approach to fulfill this requirement by exploiting the location information of nodes instead of the global topology information to route multicast messages. As the sensor nodes are often powered by batteries and recharging them is infeasible, energy-efficient routing plays an important role towards the success of WSNs. In this paper, we address this challenging issue of WSNs and propose an energy-efficient multicast geographic routing protocol (EMGR) to achieve this goal. EMGR employs an energy-aware multicast tree, formed by the set of destinations and the source node based on the metric of energy over advance, to guide multicast message delivery and adaptively select the nodes closest to the energy-optimal relay location as the next forwarders for energy conservation. Analytic and simulation results demonstrate that our proposed protocol achieves the improved performance in terms of low energy consumption, control overhead, computational complexity, and high packet delivery ratio, compared to the existing protocols.

eXplicit multicasting (Xcast) is a protocol to send data to multiple receivers in an efficient way. Compared with traditional stateful multicast, Xcast is based on a stateless approach that scales better in number of groups. Unfortunately, the original Xcast brings up new challenges such as the scalability of group size and efficiency issue. Therefore, Multiple Xcast (MXcast) and Generalized Xcast (GXcast) were proposed to retard the limitation of the group size by reconstructing the multicast group into multiple subgroups and transferring multiple Xcast packets to different subgroups, respectively. In this paper, we propose various subgrouping schemes and evaluate their performance based on hybrid simulation experiments. The results show that it can save up to 36.7% bandwidth consumption from Xcast to our proposed Optimal GXcast in Voice over Internet Protocol (VoIP). The results reflect that the proposed scheme can improve the scalability of group size, achieve minimal packet delivery latency, reduce both network bandwidth consumption and source loading compared with the unicast and original Xcast, MXcast, and GXcast.

Multicast is an important way to diffuse data in duty-cycled wireless sensor networks (WSNs), where nodes can receive data only in active state. The communication delay can be extremely large if inappropriate schedules are adopted. Unfortunately, most previous methods do not consider controlling multicast delay energy-efficiently. This paper studies the minimum active time slot augmentation for delay-bounded multicast (MAADM) problem in duty-cycled WSNs. The MAADM problem is proved to be NP-hard even under the node-exclusive interference model. An optimal algorithm is proposed for the MAADM problem when $K=2$ and a heuristic latency bounding algorithm is proposed for source-to-all communications, where $K$ denotes the number of the destination nodes. When $K>2$ , two ( $K$ −1)-approximation algorithms are designed for the MAADM problem. In addition, a low computation-complexity distributed algorithm is proposed. To the best of our knowledge, this is the first work that develops a series of efficient centralized and distributed algorithms for the MAADM problem in duty-cycled WSNs. The theoretical analysis and experimental results verify that all the proposed algorithms have high performance in terms of delivery delay and energy consumption.

Flex-grid optical networks based on orthogonal frequency division multiplexing support quite high bit rates (beyond 400 Gb/s). The flexible grid and elastic bandwidth allocation scheme of flex-grid...

Multicast is designed to jointly deliver content from a single source to a set of destinations; hence, it can efficiently save the bandwidth consumption and reduce the load on the source. In many important applications, the appearance of multiple sources brings new opportunities and challenges to reduce the bandwidth consumption of a multicast transfer. In this paper, we focus on such type of multi-source multicast and construct an efficient routing forest with the minimum cost (MCF). MCF spans each destination by one and only one source, while minimizing the total cost (i.e. the weight sum of all links in one multicast routing) for delivering the same content from the source side to all destinations. Prior approaches for single source multicast do not exploit the opportunities of a collection of sources; hence, they remain inapplicable to the MCF problem. Actually, the MCF problem for a multi-source multicast is proved to be NP-hard. Therefore, we propose two ( 2 + ɛ ) -approximation methods, named P-MCF and E-MCF. We conduct experiments on our SDN testbed together with large-scale simulations under the random SDN network, regular SDN network and scale-free SDN network. All manifest that our MCF approach always occupies fewer network links and incurs less network cost for any multi-source multicast than the traditional Steiner minimum tree (SMT) of any related single source multicast, irrespective of the used network topology and the setting of multicast transfers.

We consider the multicast scheduling problem in the heterogeneous network using a half-duplex relay station (RS). Our goal is to minimize the delay of transmitting a block of packets to users over time-varying channels using rateless codes. Due to half-duplex operation, at each time slot, the RS can choose to either multicast a packet to the users, or fetch a packet from the macro base station. We formulate a fluid relaxation for the optimal decision problem, and reveal that the optimal policy has a threshold-based structure so as to exploit the opportunism of multicast channel: the RS should multicast only when the channel quality is sufficiently “high”. We propose an online policy based on the relaxation which does not require the knowledge of channel distribution. When the channel distribution is symmetric across users, we provide a closed-form expression of the asymptotic performance of our policy. For two-user systems, we prove that our scheme is asymptotically optimal. When the users’ channels are independent, we derive a performance bound based on water-filling rate allocation which approximates the optimal policy well. Simulation results show that our scheme performs close to theoretical bounds, under correlated as well as independent fading channels.

Recently, the use of real-time multimedia applications has attracted the attention of mobile ad hoc network users. These applications support service quality. The characteristics of mobile ad hoc networks such as lack of central coordinator, mobility of hosts, dynamic changes in network topology and the limitation of access to resources have caused remarkable challenges in providing high quality services for mobile ad hoc networks. Bandwidth limitation of wireless nodes and the lack of adequate multicast trees are regarded as the main challenges for quality of service-based multicast routing. In this paper, an attempt was made to propose a more stable and more reliable in multi-path quality of service multicast routing protocol (SR-MQMR) for mobile ad-hoc networks. In the proposed method, considering the requested bandwidth, the researchers first used the signal strength of nodes to select the most stable nodes. Then, using the two parameters of route expiration time and the number of hops, we selected a route which had low delay and high stability. The results of simulations conducted in the present study indicated that the SR-MQMR protocol used less time slots than the MQMR protocol in the routing process which resulted in an increase in success ratio. Furthermore, the production of stable routes led to a significant enhancement of reliability. Since the reduction of route request packet exchange decreased overhead in the proposed method, the degree of consumed bandwidth decreased which led to an increase in network lifetime.

© 1967-2012 IEEE. Multicasting is emerging as an efficient method to deliver the same data to a group of users, thereby saving network resources. The fairness between different multicast groups is an important quality-of-service (QoS) indication, but it has not been given significant attention. In this paper, we propose a normalized signal-To-noise ratio (SNR)-based fair scheduling for multiple multicast groups in multicast systems. The system fairness and capacity are then analyzed and compared for both fair scheduling and greedy scheduling over independent but non-identically distributed (i.n.d.) fading channels. Closed-form expressions in terms of the system spectral efficiency, outage probability, system fairness, and average bit error rate (BER) are derived in an uncoded/coded M-Ary quadrature amplitude modulation based adaptive transmission multicast system over i.n.d. Rayleigh fading channels. Numerical results show that compared with greedy scheduling, fair scheduling achieves considerably high fairness at the cost of slight system capacity loss, regardless of the number of multicast groups. Our focus is on the physical layer without rate loss, but we also briefly discuss applications of the proposed scheduling in a cross-layer design subject to the loss rate QoS constraint.

The multicast framework that provides a network with multicast group management and a multicast routing algorithm is universal and exclusive, which leads to two shortcomings to multicast communication. First, the multicast framework’s default multicast routing algorithm is not specially designed for congestion avoidance, which negatively affects the quality of service (QoS) of multicast trees. Second, customized multicast routing algorithms cannot be deployed over the framework. Therefore, the multicast framework cannot simultaneously satisfy the QoS requirements of different application scenarios. To overcome these two drawbacks, we propose an innovative multicast framework that can be deployed in parallel with the existing multicast framework as a multicast plug-in for an SDN network operating system. This promising feature makes it possible to use customized multicast routing algorithms and maintain compatibility with typical multicast applications. Furthermore, based on this multicast framework, we propose a delay-constrained multicast routing algorithm that borrows ideas from anycast to actively avoid traffic congestion in multicast trees. Experimental results show that the framework is feasible and performs well, especially in high-load situations.

Continuously enriched distributed systems in data centers generate much network traffic in push-style one-to-many group mode, raising new requirements for multicast transport in terms of efficiency and robustness. Existing reliable multicast solutions, which suffer from low robustness and inefficiency in either host-side protocols or multicast routing, are not suitable for data centers. In order to address the problems of inefficiency and low robustness, we present a sender-initiated, efficient, congestion-aware and robust reliable multicast solution mainly for small groups in SDN-based data centers, called MCTCP. The main idea behind MCTCP is to manage the multicast groups in a centralized manner, and reactively schedule multicast flows to active and low-utilized links, by extending TCP as the host-side protocol and managing multicast groups in the SDN-controller. The multicast spanning trees are calculated and adjusted according to the network status to perform a better allocation of resources. Our experiments show that, MCTCP can dynamically bypass the congested and failing links, achieving high efficiency and robustness. As a result, MCTCP outperforms the state-of-the-art reliable multicast schemes. Moreover, MCTCP improves the performance of data replication in HDFS (Hadoop Distributed File System) compared with the original and TCP-SMO (an alternative reliable multicast scheme) based ones, e.g., achieves up to 1.5 × and 1.1 × improvements in terms of throughput, respectively.

Multicast communication is the concurrent transmission of data from one source node to many destination nodes. It is widely deployed in high performance computing and communication networks. In this article, wide-sense nonblocking multicast communication is studied in wavelength division multiplexing networks namely modified linear array, unidirectional and bidirectional modified ring networks. The sufficient and necessary condition on the minimum wavelength number required for the network to be wide-sense nonblocking is derived for each of the above network topologies under longest link first routing technique which employs approximately half the number of hops when compared with networks without modification. An explicit wavelength allotment technique for multicast assignment is also given for each of the above network topologies.

In-packet bloom filter based multicast is a family of techniques that have been recently proposed to address scalability issues in IP multicast. The main problem motivating these techniques is that network forwarding elements supporting traditional IP multicast store group specific forwarding state for every multicast tree traversing the element, resulting in poor memory scalability in networks with many active groups. Techniques in this family address this problem by encoding multicast routing information into in-packet bloom filters, which are memory efficient, probabilistic data structures for representing set membership. However, in existing approaches the probabilistic nature of bloom filters results in false-positive packet delivery, thereby introducing forwarding anomalies, unnecessary bandwidth utilization, and violations of security policies. In this work we contribute BloomFlow, a novel approach to bloom filter based multicast in SDN that achieves substantial forwarding state reduction while eliminating false positive packet delivery. The BloomFlow approach compensates for the stochastic uncertainty associated with bloom filters by incorporating the SDN network controller’s knowledge of the network topology and traffic workload into the generation of variable length and false-positive-free bloom filters. We further contribute a set of extensions to the OpenFlow protocol that demonstrates how our approach can be integrated into OpenFlow enabled networks with minimal modifications to switch hardware. We implement a working system prototype by extending the Stanford OpenFlow 1.0 Reference Switch and the POX SDN controller. We evaluate our approach through both flow level simulation, and packet level network emulation with Mininet and real media streams. We demonstrate that multicast forwarding using BloomFlow can achieve significant reductions in memory requirements due to network forwarding state (up to a ∼ 79% reduction in realistic WAN topologies under heavy multicast workloads). We find that this forwarding state reduction can be achieved with minimal bandwidth utilization overhead (averaging under ∼ 1%), and that our approach successfully meets time constraints required for deployment in a real-time SDN controller.

Motivated by high quality multimedia and remote collaborative environments, we solve the problem of multigroup multicast routing with a~number of features important for real-world deployment of the interactive media technologies. Based on the ant colony optimization metaheuristic, our algorithm is the first to work with uncertain knowledge of underlying network capabilities and support on-the-fly media transcoding inside the multicast tree. New contributions of this work are described next. We present two extensions of the algorithm, which improve quality of the solution. We introduce an~integrated approach to solution of the problem, which is effective for both original solving from scratch as well as for new dynamic reconfiguration of multicast tree, where minimum perturbation of existing solution is desired. Experiments show that our algorithm is not only successful in maintaining existing communication with low number of unnecessary disruptions, but also capable of keeping the multicast trees efficient.

Multicast and prefix caching are two promising approaches to provide scalable video-on-demand (VoD) services. We contribute to solve the adaptive multicast delivery and the cache allocation problem for VoD services with client caching under asynchronous client requests. We first propose a client caching enabled adaptive multicast delivery scheme, which combines the stream merginglike method with prefix caching and adaptive modulation and coding, to fully exploit the multicast opportunity among asynchronous requests from heterogeneous clients. Next, we derive the bandwidth consumption of the proposed delivery scheme under a given prefix cache allocation and Poisson arrival request. We then optimize the cache allocation to minimize the average bandwidth consumption, and the problem is proved to be convex and solved effectively. Finally, three extreme cases are studied to provide closed-form solutions and more insight on the cache allocation and the delivery scheme for VoD systems.

Cognitive wireless mesh networks (CWMNs) were developed to improve the utilization ratio of licensed spectrum. Since the spectrum opportunities for users vary over time and location, enhancing the spectrum effectiveness is a goal and also a challenge for CWMNs. Multimedia applications have recently generated much interest in CWMNs supporting quality-of-service (QoS) communications. Multicast routing and spectrum allocation is an important challenge in CWMNs. In this paper, we study to design an effective multicast routing algorithm based on diversity rate with respect to load balancing and the number of transmissions for CWMNs. In this paper, a load balancing wireless links weight computing function and computing algorithm based on diversity rate (DRLB) are proposed, and a load balancing channel and rate allocating algorithm based on diversity rate (DR2CS) is proposed. On this basis, a load balancing joint multicast routing, channel and rate allocation algorithm based on diversity rate with QoS constraints for CWMNs (LMR2D) is proposed. Balancing the load of node and channel, and minimizing the number of transmissions of multicast tree are the objectives of LMR2D. Firstly, LMR2D computes the weight of wireless links using DRLB and Dijkstra for constructing the load balancing multicast tree step by step. Secondly, LMR2D uses DR2CS to allocate channel and rate of channel to links which is based on the wireless broadcast advantage. Simulation results show that LMR2D can achieve the expected goal. It can not only balance the load of node and channel, but also need lower number of transmissions for multicast tree.

Reliable and QoS-aware multimedia delivery is one of the most important requirements to satisfy end user needs. IEEE 802.11 networks have become one of the most popular Internet access methods owing to their low-cost and fast connection speed. Multicasting is a transmission technique that can significantly increase network efficiency through the simultaneous delivery of the same multimedia content to multiple multicast group members. IEEE 802.11 describes several multicast protocols targeted to increase the robustness of audio and video delivery. Some researchers have investigated the performance of such multicast protocols in terms of their achievable throughput. However, for a better understanding of the suitability of the protocols for a QoS-aware multimedia transmission, an in-depth analysis of the achievable delay is needed. This study provides a detailed delay analysis and describes analytical models for estimating the average achievable delay of IEEE 802.11 multicast protocols co-existing with legacy stations. The proposed analytical models are compared against simulation results under various conditions and parameter configurations. The simulation results validate the accuracy of the proposed models.

Smart Grids (SGs) are emerging cyber-physical systems, equipped with sophisticated communication and information technologies, for efficient and large-scale power supply and management. SGs demand advanced communication technologies between energy providers and consumers, for enabling a control-feedback loop, by using time-dependent pricing. In this paper, we propose an efficient planning of 5G small cells, with evolved multimedia broadcast and multicast communication, between aggregators (small cells) and SG consumers, for efficient demand-response (DR) programs. After pointing out that optimal multicast scheduling and radio resource management problem is NP-complete, we propose two different solutions, based on dynamic programming (DP) and greedy heuristics, for minimizing the energy cost for DR customers. We also analyze the performance of SG user capacity for 5G single cell multicast and multicast broadcast single frequency network. Extensive OPNET simulation results, over actual energy data and real wireless trace, demonstrate that our proposed 5G small cell planning and multicast solutions are capable of reducing energy production cost by $30\%$ , with up to $35\%$ shift in peak energy load, low latency and packet drop.

Secondary users (SUs) can flexibly access licensed channels to improve the spectrum utilization in cognitive radio networks (CRNs). In mobile cognitive radio ad hoc networks (MCRAHNs) where nodes can move, SUs are intermittently connected because of node mobility, as well as the uncertain channel availability. Providing multicast services in MCRAHNs is urgently needed with the compelling demand on service qualities and varieties, and the proliferation of cognitive technology. The benefits of network coding over multicast in traditional wireless networks or CRNs have been well demonstrated in existing works. However, the existing studies merely address the two crucial issues (i.e., uncertain channel availability and node mobility) together and, thereby, cannot be applied to network coding-based multicast in MCRAHNs. In this paper, we study the problem of network coding-based multicast in MCRAHNs considering both channel uncertainty and node mobility. We utilize discrete-time Markov chains to model the channel availability and node mobility in MCRAHNs, and we then formulate a spectrum-aware network coded multicast problem as an optimization problem, which minimizes the total transmission cost, subject to the timely successful delivery constraint and link transmission constraint. Since the formulated problem is hard to tackle according to mixed integer programing, we further design a distributed spectrum-aware cost-based (SACB) scheme based on the metric of forwarding benefit. With extensive simulations based on both synthetic and realistic traces, we show that, compared with existing schemes, SACB can achieve almost the minimum transmission cost while maintaining high multicast success probability.

Wireless links are inherently lossy due to channel fading or interference. Previously, duplicate packets were transmitted on multiple routes of lossy mobile ad hoc networks (MANETs) to enhance reliability. In this paper, a multicast routing protocol that constructs multiple multicast trees and employs network coding is proposed for lossy MANETs, where each multicast tree can satisfy a predefined percentage of the bandwidth requirement. The proposed protocol can reduce the total bandwidth consumption while providing bandwidth guarantees to a requested flow and ongoing flows. As a consequence of employing network coding, no redundant packet is generated, and no scheduling algorithm for distributing packets among the multicast trees is needed. Simulation results show that the proposed protocol outperforms prior multicast routing protocols in terms of the receiving ratio, the admission ratio, and the total bandwidth consumption.

Distributed mobility management (DMM) is currently being researched and standardized in academia and standardization development organizations for the purpose of overcoming the major issues of existing centralized mobility management. The most recent DMM protocols are being redesigned with regard to the control and data plane separation concept. However, at present, there is no solution for supporting IP multicast listeners in such new DMM environments. In this paper, we review ongoing academic research works, standardization activities and propose an IP multicast mobility design for the DMM environment using the control and data plane concept.

The graphical abstract in the form of Pareto front solutions showing the trade-offs between the objectives is depicted in Fig. 1.Display Omitted Wireless networks have finite battery source, so QoS aware multicast routing must also be energy efficient.There is trade-off between energy consumption and QoS guarantees (i.e. end-to-end delay, delay jitter and packet loss) provided by a wireless network.These requirements are formulated as a multiobjective optimization problem.Ant based multiobjective algorithms are proposed to build an energy efficient multicast tree.Simulation results are compared with NSGA-III. Most of the group communication technologies support real-time multimedia applications such as video conferencing and distributed gaming. These applications require quality-of-service (QoS) aware multicast routing protocol to deliver the same data stream to a predefined group of receivers. Since nodes in wireless networks are severely energy constrained due to finite battery source, hence it is of paramount importance that QoS aware multicast routing protocol be energy efficient. Transmission power control is one of the methods used to save energy. In this method, the nodes dynamically adjust the transmission power so that energy consumption in the tree is minimized. However, reduction in the transmission power increases the number of forwarding nodes in the multicast tree. This negatively impacts the QoS in terms of propagation delay, delay jitter, and packet loss etc. In wireless networks, there is a trade-off between the energy consumption and the QoS guarantees provided by the network. We unify these requirements into a multiobjective framework referred to as Energy Efficient QoS Multicast Routing (E2QoSMR). The goal is to simultaneously optimize the total power consumption and the QoS parameters in the multicast tree. We extend two algorithms based on metaphor of swarm intelligence for finding an energy efficient multicast tree satisfying the QoS guarantees. Extensive simulations have been conducted to validate the correctness and efficiency of the algorithms. The simulation result of the algorithms is compared with the nondominated sorting genetic algorithm, NSGA-III. The experimental results are consolidated by statistical analyses that demonstrate the ability of the algorithms to generate the Pareto optimal solution set.

We propose and investigate a subtree scheme for all-optical multicast routing, modulation level and spectrum allocation (AOM-RMSA) in elastic optical networks. A multicast request is accommodated by several light-trees and each light-tree covers only a part of the destination set. We assume that all nodes are multicast capable and investigate the subtree scheme over the single light-tree scheme for the AOM-RMSA problem under both static and dynamic traffic scenarios. In the static scenario, we formulate an integer linear programming model to obtain the optimal solution. Then, we propose two time-efficient heuristic algorithms that construct subtrees according to the link-sharing ratio between the paths from source to two distinct destinations. The proposed algorithms improve the spectrum utilization by building subtrees that have smaller tree-spanning size and adopt higher level modulation formats. They have also effectively reduced the blocking probability compared to single light-tree schemes.

With the rapid evolution of multimedia and real-time applications like audio/video conferencing, certain quality-of-service (QoS) should be guaranteed for the multicast transmission. For the given delay-constrained multicast request, the goal of delay-constrained survivable multicast routing problem (DCSMRP) is to provide the primary multicast tree and protecting resources so that after recovering from the link (node)-failure, the recovered tree can satisfy the delay constraint. In this article, the DCSMRP with a single node-failure case on wavelength-division multiplexing (WDM) networks is considered. Three node-failure protecting methods, includes node-disjoint trees (NDT), node-encircling p-cycles (NEPCs) and failure-independent path protecting p-cycles (FIPP p-cycles) are used in this article. For each protecting method, an algorithm is designed to solve the studied problem. Simulations are also conducted to evaluate the performance of the proposed algorithms.

With the growing trend of deploying Software defined networks (SDN) in Internet and data centers, it is necessary to investigate the operation of multicast services in this paradigm shift. We propose an OpenFlowbased virtualized platform to support multiple multicast services simultaneously, each with their own customized multicast algorithms and performance-enhancing strategies for its service requirements. The contributions include: 1) systematic discussions of the technical challenges re-garding to implementing multicast services in SDN, with the proposed architectural components addressing these issues; 2) a virtualized platform enabling user-defined multicast services, independent of current Internet-based protocols; 3) experiments validating the necessity and efficiency of the platform in supporting its design goals and functionalities, with two additional real multicast applications further confirming the feasibility and operability of the proposed prototype.

Today’s multiprocessor platforms employ the network-on-chip (NoC) architecture as the preferable communication backbone. Conventional NoCs are designed predominantly for unicast data exchanges. In such NoCs, the multicast traffic is generally handled by converting each multicast message to multiple unicast transmissions. Hence, applications dominated by multicast traffic experience high queuing latencies and significant performance penalties when running on systems designed with unicast-based NoC architectures. Various multicast mechanisms such as XY-tree multicast and path multicast have already been proposed to enhance the performance of the traditional wireline mesh NoC incorporating multicast traffic. However, even with such added features, the multihop nature of the wireline mesh NoC leads to high network latencies and thus limits the achievable system performance. In this paper, to sustain the high-bandwidth and high-throughput requirements of emerging applications, we propose the design of a wireless NoC (WiNoC) architecture incorporating necessary multicast support. By integrating congestion-aware multicast routing with network coding, the WiNoC is able to efficiently handle heavy multicast injections. For applications running with a broadcast-heavy Hammer cache coherence protocol, the proposed multicast-aware WiNoC achieves an average of 47% reduction in message latency compared with the XY-tree-based multicast-aware mesh NoC. This network level improvement translates into a 26% saving in full-system energy delay product.

In this paper, joint multicast routing and channel assignment problem in wireless mesh networks (WMNs) with hybrid traffic is investigated. Previous works design routing and channel assignment schemes for WMNs with single multicast session, however, resource usage is optimized for only one multicast session in this case and overall network load balance is left out of consideration. This may result in high congestion in some links, while others are underutilized. In this paper, multicast routing and channel assignment problem is solved from traffic management perspective by introducing load balance. Programming formulation is formulated to obtain the optimal results which can be used as benchmark to evaluate other schemes. Multicast weighted conflict graph is designed to model partially overlapped channels (POCs) interference in hybrid traffic scene. It regards links originating from the same node as one transmission to fully exploit wireless broadcast advantage; it uses link weight to measure interference degree and gives full consideration to interference characteristics of POCs. A heuristic multicast routing and channel assignment scheme based on multicast weighted conflict graph is designed to solve the joint problem, and simulation results show that the heuristic scheme can reduce network interference and improve WMNs service capability while dramatically reducing computational complexity.

Nowadays, several advanced ICT infrastructures demand multicast services able to jointly provide a high degree of reliability and good performances despite of failure occurrences. The current practice to tolerate failures in such services mainly consists in the adoption of methods based on temporal redundancy, where messages are successfully delivered to all the interested destinations by means of retransmissions. However, in such methods, a high degree of reliability is typically obtained at the expenses of severe performance fluctuations and instability. On the contrary, approaches that make use of forward error correction imply a more performance-friendly behavior; however, the effective tuning of such approaches is a critical and challenging task, which has limited their applicability in large-scale multicast services. This paper is aimed at presenting a solution to resolve this issue by effectively tuning the redundancy degree to be applied, so as to be able to tolerate the losses affecting the multicast communications without an excessive, and un-needed, workload imposed over the network. To this aim, we drawn from the experience of layered multicast, commonly applied to multimedia content delivery, for addressing such tunability problem. Specifically, we detail how to apply layered multicast within the context of a well known multicast service and how to determine the correct redundancy degree to be applied. We also make use of extensive simulations to evaluate the quality of the proposed approach in terms of reliability, performance and overhead, and to compare it with the best retransmission-based approach available in the literature.

Multicast routing improves the efficiency of a network by effectively utilizing the available network bandwidth. In multichannel multiradio wireless mesh networks the channel allocation strategy plays a vital role along with multicast tree construction. However, the multicast routing problem in multichannel multiradio wireless mesh networks is proven to be NP-hard. With this paper, we propose a Quality of Service Channel Assignment and multicast Routing (Q-CAR) algorithm. The proposed algorithm jointly solves the channel assignment and multicast tree construction problem by intelligent computational methods. We use a slightly modified differential evolution approach for assigning channels to links. We design a genetic algorithm based multicast tree construction strategy which determines a delay, jitter bounded low cost multicast tree. Moreover, we define a multi objective fitness function for the tree construction algorithm which optimizes interference as well as tree cost. Finally, we compare the performance of Q-CAR with QoS Multicast Routing and Channel Assignment(QoS-MRCA) and intelligent Quality of service multicast routing and Channel Assignment(i-QCA) algorithm in multichannel multiradio wireless mesh network (simulated) environments. Our experimental results distinctly show the outstanding performance of the proposed algorithm.

With Software Defined Networking (SDN), IP multicast becomes promising again. For IPTV applications over SDN, existing works would not scale well since they are based on per-source trees. As control-plane in SDN is logically centralized, constructing multiple shared trees is more feasible than that in traditional IP networks. Thus, in this work, we present a locality-aware multicast approach (LAMA) to construct multi-group shared trees in SDN, where each shared tree covers multiple multicast groups. In LAMA, the controller first clusters the multicast sources located in the vicinity into the same multicast cluster. For each multicast cluster, the controller selects the center switch which has the minimum distance to all multicast sources as its rendezvous point (RP) and then constructs a shortest-path multicast tree from the RP to its hosts. Finally, based on the multi-group shared trees, the controller can establish coarse-grained flow entries into on-tree switches to reduce the number of installed flow entries. Emulations on the Ryu controller and the Mininet emulator show that only 2-5 shared trees would suffice. The computation time in the controller using LAMA is around 70ms, much less than hundreds ms required for per-source trees. Moreover, LAMA only establishes 2300 flow entries, 4% of that with per-source trees in a large topology.

With the advance of multimedia and pattern recognition based medical technologies, smart medical applications in smart hospital and smart medical for individual, such as disease diagnosis and health monitoring, play an important role in our life. However, the communication infrastructure of supporting these applications is a challenge. This paper studies the energy-efficient multicast routing problem in multi-hop wireless networks for these medical applications. Energy consumption has become the main problem of sustainable development of communication networks, particularly for these applications. How to carry out high energy-efficient communication is an important research topic for wired and wireless networks to implement green communications. This paper proposes an energy-efficient multicast routing approach to multi-hop wireless networks for smart medical applications. Different from previous methods, we aim at maximizing energy efficiency of networks. To this end, we make use of topology control and sleeping mechanism to obtain the optimal routing strategy with maximum network energy efficiency to construct the network multicast route. Simulation results show that the proposed approach is effective and feasible.

In many Internet of Things (IoT) applications, messages may need to be disseminated to some specific objects or nodes using multicast transmissions. In the literature, the multicast routing protocol can be divided into non-geographic-based and geographic-based. Since devices locations can be roughly derived by localization schemes or by GPS devices, geographic-based multicast routing protocols are preferred since they can induce less control packet overheads. However, we observe that existing geographic-based multicast routing schemes have the following two drawbacks. First, network nodes need a lot of computations to decide directions of sending multicast packets. Second, when a network has some holes or voids, the constructed multicast paths will be long, and in some cases, the paths may contain loops. In this work, we proposed a lightweight and distributed geographic multicast routing protocol to solve the above problems. Our scheme contains three phases. First, the first phase selects intermediate nodes to reach multicast destinations. Then, the second phase removes loops and trims routes constructed in the first phase. Finally, the last phase checks if the selected multicast links can further be merged. The simulation results indicate that the proposed scheme can effectively reduce transmission links and shorten path lengths in the constructed multicast paths. To demonstrate the proposed scheme can be applied to IoT applications, we also implement the designed scheme in ZigBee-compliant platforms. The experiment results show that the proposed scheme can also help to reduce multicast latency.

It is known that to support the applications such as datacenter backup and migration, multicast should be supported efficiently in inter-datacenter (inter-DC) networks to carry the corresponding point-to-multiple-point communications. Moreover, due to the traffic dynamics in inter-DC networks, we might have to consider the case that the multicast members can join or leave a multicast session dynamically. Therefore, in this work, we try to leverage control plane innovations to realize dynamic formulation of multicast sessions in inter-DC software-defined elastic optical networks (SD-EONs), which are equipped with multicast-incapable bandwidth-variable wavelength selective switches (MI-BV-WSS'). Here, one key issue to address is that the continuous changing of multicast group members can degrade the optimality of a multicast-tree. Hence, we propose to rearrange the multicast-trees adaptively to reduce their spectrum usage. Meanwhile, we try to minimize the frequency of rearrangements to avoid unnecessary operation complexity. Based on these considerations, we propose several multicast-tree rearrangement algorithms for updating multicast sessions dynamically with lightpath reroutings in inter-DC SD-EONs. Both partial and full multicast-tree rearrangements are studied. Simulation results indicate that the proposed algorithms can rearrange the multicast-trees intelligently such that the blocking probability can be reduced effectively with the least lightpath reroutings. Next, based on these theoretical investigations, we consider how to implement the proposed algorithms in the control plane of an inter-DC SD-EON. We extend the OpenFlow (OF) protocol to support the dynamic formulation of multicast sessions and also design the functional models in the control plane elements to realize multicast-tree rearrangements. Experiment results verify the effectiveness of our proposed algorithms and system design.

The mobile environment in MANETs (Mobile Ad hoc Networks) itself is a major constraint to deal with, and assuring reliability on the top of that strengthens the problem more. This paper which is entirely an extension of the authors' previous work based on trust based group formation using Fuzzy Logic. They herein propose a model which is highly inspired by natural and social behavior of human beings that man is a social animal and is always associated with different types of dynamic groups. Before ensuring the reliable route take into account the trust (T) and the speed (S) of the intermediate nodes which may take part in routing. Trust is actually a matter of feeling with which one feels connected with some person/s in the form of multicast groups. Thus, the proposed Multicast Route Reliability (MRR) is a purely a probabilistic function of Cartesian product of past relationships and present moving patterns.

Nowadays, the transition of Wireless Sensor Networks (WSNs) to Internet Protocol version 6 (IPv6), in particular to IPv6 over Low power Wireless Personal Area Networks (6LoWPAN), is evident [1] . However, in most commonly used implementations, not all IPv6 features are available. For example, current implementations are not very optimized for multicast, despite the many benefits multicast can offer with respect to the number of radio transmissions and the amount of consumed energy. In this paper we present Bidirectional Multicast RPL Forwarding (BMRF), a new multicast protocol that combines the best features of the Routing Protocol for Low Power and Lossy Networks (RPL) multicast on the one hand and of Stateless Multicast RPL Forwarding (SMRF) on the other hand. The main features are bidirectionality and the ability to offer a choice between Link Layer broadcast and Link Layer unicast for which the threshold to decide for a mote, which link layer mode to choose, is mainly based on its number of interested children and the duty cycling rate. An implementation of BMRF is realized in Contiki. Our measurements show that BMRF, when using the optimal configuration, results in less radio transmissions, and less energy consumption, and higher packet delivery ratio compared to SMRF, often at the cost of a higher end-to-end delay.

With the development of multimedia services in Internet technology, there comes a big gap between bandwidth utilization and the blocking probability for multicast requests in the optical wavelength division multiplexing (WDM) networks. The objective of the proposed approach is to minimize the number of requests blocked in a dynamic multicast optical networks by minimizing the total resources (such as transceivers, splitters and wavelengths) used by the requests and simultaneously increase the bandwidth utilization. Since there are multiple wavelengths on a WDM optical fiber of fixed capacities, minimizing the number of wavelengths to be used is a variation of the bin packing problem. In the bin packing problem, multicast requests of different granularities or subwavelengths must be packed into a finite number of wavelength channels, in such a fashion that it minimizes the number of wavelengths used. In computational complexity theory, it is a combinatorial NP-hard problem. Therefore, we propose two heuristic approaches that provide the efficient resource utilization. These algorithms are called Multicast Traffic Grooming with Bin packing Best-Fit (MTG-BBF) and Multicast Traffic Grooming with Bin packing First-Fit (MTG-BFF). Both the algorithms are derived from standard Bin pack heuristic approach and we map our problem with such kind of approach. Our simulations demonstrated that both the algorithms significantly reduce the blocking probability (BP) compared to well known existing algorithms and MTG-BFF produces slightly better performance than MTG-BBF in the standard networks.

With the ever-increasing demands for popular content sharing among humans, device-to-device (D2D) multicast communication, as a promising technology to support wireless services within a local area, is introduced in a 5G cellular network. However, the existing resource allocation approaches for D2D multicast communication usually consider only physical domain constraints but neglect social domain factors, which would result in ineffective D2D links between users unwilling to share interests. Different from existing works, the D2D multicast scheme proposed in this paper will produce effective D2D multicast links by sufficiently utilizing both the physical and social properties of mobile users, with the goal to maximize the throughput of the overall social-aware network and guarantee fairly allocation of the channel between different D2D multicast clusters. The scheme mainly consists of two parts, the formation of D2D multicast clusters and joint optimization of power and channel allocation. In the formation of D2D multicast clusters, members and head in each cluster are selected by taking into account both social attributes and physical factors, such as community, ties, and geographical closeness. In the joint optimization, a two-step scheme is designed to first calculate the optimal power allocation by geometric proximity and then select suitable cellular channels for each D2D multicast cluster utilizing an extended one-to-many bipartite graphs matching algorithm. Simulation results demonstrate that, compared with heuristic algorithm and stochastic algorithm, the proposed scheme can increase the throughput of the overall social-aware network by about 5% and 50%, respectively.

Existing literature on multicast routing protocols in wireless mesh networks (WMNs) from the view point of the links involved in routing are divided into two categories: schemes are aimed at multicast construction with minimal interference which is known as NP hard problem. In contrast, other methods develop network-coding-based solutions with the main objective of throughput maximization, which can effectively reduce the complexity of finding the optimal routing solution from exponential to polynomial time. The proposed framework in this paper is placed in the second category. In multi-channel multi-radio WMNs (MCMR WMNs), each node is equipped with multiple radios, each tuned on a different channel. In this paper, for the first time, we propose a cross-layer convex optimization framework for joint channel assignment and multicast throughput maximization in MCMR WMNs. The proposed method is composed of two phases: in the first phase, using cellular learning automata, channels are assigned to the ...

The current mobile packet core network is evolving to cope with the pressure of the mobile traffic explosion and the advent of new services. Software-defined networking (SDN) is currently being adopted as one of the promising drivers for redesigning the mobile packet core network toward a 5G network. SDN-based mobile packet core approaches are expected to deliver features, such as fast service deployment, flexibility, and capital expenditure and operational expenditure reduction within future 5G networks. However, current SDN-based mobile packet core approaches only focus on providing unicast services without considering multicast and broadcast services. In this article, we propose an efficient SDN-based mobile packet core network architecture for supporting multicast and broadcast services. The proposed architecture takes advantage of the SDN paradigm and enables multicast and broadcast service deployment. In addition, a new SDN-based multicast subscription procedure is introduced to reduce network bandwidth resources. By numerical analysis, our scheme improves the current multicast and broadcast solution in terms of signaling cost.

The availability of bandwidth in wireless mesh networks (WMNs) introduces it as a prominent choice for implementing bandwidth sensitive services. Multicast services such as teleconferencing, push-based systems, multiplayer games, etc., can be implemented in an efficient way in such networks. Moreover, the severe performance degradations that can result from the interference generated by concurrent data transmissions and environmental noises call for the development of interference-aware routing mechanisms. This paper investigates the impact of wireless interference on network performance for multicast transmission in WMNs. We show that by taking wireless interference into consideration in the design of routing mechanisms, better resource usage can be achieved. Hence, a fuzzy logic–based approach is proposed to choose optimal routes from source to the multicast group in multichannel case. Three fuzzy variables are considered in route selection phase, which are interference, available bandwidth, and...

Multicasting is an efficient data transmission approach for group communication applications in multi-channel multi-radio wireless mesh networks. In this paper we have studied the problem of accepting on-line multicast requests, which is quite important for supporting multimedia applications. Our proposed algorithm investigates the acceptance of an arrived call in two phases. In the first phase, a loop-free mesh backbone is constructed. In this mesh, the set of possible parents of each node is limited to the neighbors that are one hop closer to the source node. The neighbors with the same distance from the source node are also acceptable under the circumstance that two neighboring nodes cannot be the possible parents of each other. Next, a sub-optimal mathematical model has been proposed for tree construction over the obtained mesh. The derived multicast trees utilize the minimum amount of bandwidth; are load-balanced; and exploit wireless broadcast advantage. The results show that the proposed algorithm improves the rate of multicast call acceptance by 40% on average compared to previous algorithms in a short running time.

Opportunistic Mobile Social Networks (OMSNs), formed by people moving around carrying mobile devices, enhance spontaneous communication among users that opportunistically encounter each other without additional infrastructure. Multicast is an important communication service in OMSNs. Most of the existing multicast algorithms neglect or adopt static social factors that are inadequate to catch nodes’ dynamic contact behavior. In this paper, we introduce dynamic social features and its enhancement to capture nodes’ contact behavior, consider more social relationships among nodes, and adopt community structure in the multicast compare-split schemes to select the best relay nodes to improve multicast efficiency. We propose two multicast algorithms based on these new features. The first one Multi-CSDO involves destination nodes only in community detection while the second one Multi-CSDR involves both the destination nodes and the relay candidates in community detection. The analysis of the algorithms is given and simulation results using two real OMSN traces show that our new algorithms outperform the existing ones in delivery rate, latency, and number of forwardings.

A number of today’s over-the-top (OTT) services could greatly benefit from a flexible, efficient, and scalable network-layer multicast support on the Internet. IP multicast showed not to meet these requirements, hindering its adoption in more than individual network islands. As a consequence, content delivery networks (CDNs) emerged as alternative and implemented one-to-many multicasting at the application layer. Yet, due to practical reasons and conflicting stakeholder interests, CDN deployments usually end at the border of Internet service provider networks, making one-to-many deliveries at an Internet-scale challenging up to date. In a previous work, the authors presented software-defined multicast (Sdm) to mitigate this problem by unlocking network-layer multicast support for OTT services inside ISP networks. In this paper, DynSdm is proposed to complement Sdm in key aspects, allowing for a more holistic support of relevant scenarios aspects, and enabling a fine-granular traffic engineering of multicast traffic inside ISP networks. For this, DynSdm presents a detailed design of the ISP-internal traffic and service management process and introduces a set of novel SDN-based network-layer mechanisms for traffic load balancing as well as handling of group and network dynamics. DynSdm was implemented as prototype and extensively evaluated, showing its flexibility, high traffic efficiency, good scalability, and superior ability to balance traffic load inside ISP networks.

Dynamic data transfer demands are often being a challenge for present communication networks, as they appear in unpredictable time and must be satisfied prior to deadline. Important kind are the multi-target demands occurring in task of replication, backup, database synchronization or file transferring in pear-to-pear networks. Optimal scheduling usually depends of the nature of transport network. In the paper dynamic deadline-driven multicast scheduling problem over elastic optical network is considered. Particularly, the method for improving link utilization by traffic balance for multicast demands is proposed. Few heuristic algorithms and results of experiments, proving the benefits of balancing concept are presented