Layer Multicast Research Articles

Research on Fast Application Layer Tree Multicast Algorithm Based on End-to-End Measurement

Application Layer Multicast (ALM) is more flexible than that in IP layer and easy to optimize for specific applications, so the research on it has become a hotspot. Aiming at the problem of most ALM protocol ignoring bandwidth of covering tree, the paper presented a new heuristic algorithm Max-Delta, which inferred the underlying link topology using end-to-end measurement technology. On the basis of this, a kind of Fast Application layer Tree (FAT) algorithm to construct covering tree was proposed to meet the requirements of bandwidth. In addition, the algorithm's time complexity was also analyzed. Simulation results show that Max-Delta algorithm can obtain network topology accurately with less network measurement times comparing with random measurement algorithm and longest path measurement algorithm.

Overlay tree construction to distribute layered streaming by application layer multicast

With the development of broadband technologies, more and more multimedia contents such as video or bulk file are being distributed over the Internet. However, an important issue to be resolved is how to construct an efficient overlay to provide users with the acceptable throughput and delay, while receiving multimedia contents. Therefore, this paper designs a tree construction algorithm by distributing the layered steaming over the ALM in order to improve both throughput and user delay. Firstly, to improve the throughput, based on theory analysis, we define a layered degree, out/in-degree and the corresponding constraints to manage the layered streaming and nodes. Secondly, a novel method, called Bi-cast, is proposed to reduce user delay during data-transmission. Thirdly, by using the defined degrees and the Bi-cast, we present a tree construction algorithm. Both the simulation and the implementation are carried out, and the results show that our proposal can obtain better performance than other conventional methods.

Layered video multicast with a P2P cooperation approach

With the rapid development of wireless networking technology, real time video multicast applications have become feasible. These applications are bandwidth hungry and have stringent delay constraints. Furthermore, in wireless networks, different users generally have different receiving capabilities. Therefore, it is challenging to provide scalable support for such applications. To address this challenge, in this paper, we propose to use layered video and a P2P mode approach. In our solution, a video is encoded into multiple layers and broadcast to the multicast group users. Users form a P2P network to recover the loss of multicast video packets. This can significantly improve the overall received video quality. More importantly, our solution can provide incentives for users to help each other. With the proposed scheme, when a user helps another one, it can also improve its own received video quality.

Using Binning for Tree Construction in Application

The application Layer Multicast (ALM) is an alternative and deployable approach to IP multicasting. Topology awareness link stress and delay stretch considerably, therefore it is a very important metric for ALM. This work describes a novel, highly stable and low overhead ALM approach using a binning technique to cluster nearby receivers, referred to as Bincast. Bincast uses a constant number of landmarks to cluster nearby nodes. Then, it constructs a k-ary tree between cluster members. The most stable node is selected as the head of each cluster. Cluster heads are connected to the source through a higher level tree. Detailed performance evaluation revealed that Bincast has a lower delay stretch than similar methods with approximately the same stress. Besides, it is more stable due to the selection of stable nodes as cluster heads.

A framework for reliability aware layered multi-cast in lossy networks with network coding

This paper provides an explicit framework for reliability aware layered multi-cast of multimedia data in a lossy network coded by a static network code. In a lossy network, a data packet multi-cast from a source arrives at each destination successfully only with some probability. Destinations are heterogeneous in their maximum receiving rates, which are the maximum-flow rates through the network. The proposed framework first formulates the problem of assigning a transmission infrastructure (network subgraph) as well as a set of destinations to each multi-cast layer as a binary integer linear programming problem that can be solved using standard techniques. These infrastructures are selected subject to the reliability constraints for individual destinations in each multi-cast layer. To facilitate a network code construction for each layer with reliability awareness, the framework next provides an algorithm to generate a set of success patterns of link transmissions to be taken into account during code construction. Based on this set of success patterns, a static network code construction algorithm is proposed in order to create a static network code that allows a subset of destinations with sufficient receiving rates to receive the layer information. The resulted network code provides reliability for the infrastructures selected from the first step. Numerical results are provided to demonstrate the advantages of our framework in providing reliable layered multi-cast to heterogeneous destinations.

Poster abstract

Wireless multicast is an important service primitive for emerging applications such as live video, streaming audio and content telecasts. Transmission rate in such a link layer multicast is bottlenecked by the rate of the weakest client, leading to channel under-utilization. Attempts to increase the data rate results in lower reliability (due to higher bit error rate) and higher unfairness. This poster utilizes smart beamforming antennas to improve multicast performance in wireless LANs. The main idea is to satisfy majority of the (strong) clients with a high-rate omnidirectional transmission, followed by high-rate directional transmission(s) to cover the weaker ones. By selecting an optimal transmission strategy, we show that the multicast throughput can be maximized while achieving a desired delivery ratio at all the clients. We use testbed measurements to verify our main assumptions. We simulate our protocol in Qualnet, and observe consistent performance improvements over a wide range of client topologies and time-varying channel conditions.

An Iterative Application Layer Multicast Tree Construction for Multi-source Multimedia Communication and its Evaluation

An Iterative Application Layer Multicast Tree Construction for Multi-source Multimedia Communication and its Evaluation

An Interest Management Architecture by ALM and Region Partition for Large-Scale Distributed Virtual Environment

Large-Scale Distributed Virtual Environments (LSDVEs) must deal with the challenge of supporting a large number of users interacting on the Internet while keeping the communication among the parties synchronous and highly reactive. Interest Management is widely used to filter unnecessary messages in such systems. We present an interest management architecture that supports a large number of users on the Internet by dividing the virtual environment into multiple adjacent hexagonal regions. In the architecture, messaging among entities is based on a multi-server communication infrastructure by the Application Layer Multicasting (ALM). And each region is mapped to an ALM tree with a master node constructing the overlay tree and managing nodes that lie in its region. The interest area of each entity is composed of two parts: the inner hexagon and outer hexagon. By the two parts, inter-region as well as intra-region interaction is supported to maintain a continuous view without increasing too much traffic. In addition, the buffer borderlines near the boundaries are introduced to reduce the number of connections and disconnections that occur when a node frequently moves at the boundary of the regions without affecting the messaging of the entities and modifying the partition structure.

Customized Forwarding in application layer multicast for real-time services

We propose a customized forwarding (CF) scheme for tree-based application layer multicasts to support real-time interactive multimedia services. We show that CF reduces residual loss rate and play pause frequency significantly.

Self-organized hierarchical key management scheme for application layer multicast

To solve the scalability and high delay problem in Application-Layer Multicast (ALM) group key management,SOKM,a self-organized large-scale hierarchical ALM group key management scheme was proposed. In this scheme,a special node in each cluster was chosen to be Key Server (KS),which confined the updating and management of group keys in cluster only. Analysis and simulations show that,compared with MHKM scheme,SOKM has the advantages of reducing the probability of KS being attacked and key forwarding delay,which lead to higher security of multicast group and key forwarding rate,although the computation rises. Consequently,MHKM has preferable scalability.

Bus-type model based on comprehensive performance of node for application layer multicast

In order to improve the performance of Application Layer Multicast (ALM),bus-type model based on comprehensive performance for application layer multicast (CPBM) was proposed,which introduced both hierarchy architecture and the comprehensive performance of node. Dynamic programming method based on the comprehensive performance of node was used in CPBM,so that the system could adjust the location of each node automatically according to its comprehensive performance. Besides,in every cluster,the nodes followed into a bus-type with their comprehensive performance from high to low,and the node with highest comprehensive performance was selected as the Leader node. Simulation results show that CPBM possesses higher data delivery ratio and bandwidth usage compared with NICE,so that it can improve the performance of application layer multicast fairly well to some extent.

Reliable Application Layer Multicast Over Combined Wired and Wireless Networks

During the last several years, the Internet has evolved from a wired infrastructure to a hybrid of wired and wireless domains by spreading worldwide interoperability for microwave access (WiMAX), Wi-Fi, and cellular networks. Therefore, there is a growing need to facilitate reliable content delivery over such heterogeneous networks. On the other hand, application layer multicast (ALM) has become a promising approach for streaming media content from a server to a large number of interested nodes. ALM nodes construct a multicast tree and deliver the stream through this tree. However, if a node leaves, it cannot deliver the stream to its descendant nodes. In this case, quality-of-service (QoS) is compromised dramatically. Especially, this problem is exacerbated in wireless networks because of packet errors and handovers. In order to cope with this problem, multiple-tree multicasts have been proposed. However, existing methods fail to deliver contents reliably in combined wired and wireless networks. In this paper, we propose a method to ensure the robustness of node departure, while meeting various bandwidth constraints by using layered multiple description coding (LMDC). Finally, we evaluate the proposed method via extensive simulations by using the network simulator (ns-2). By comparing our proposed method with the existing ones, we demonstrate that our method provides better performance in terms of total throughput, relative delay penalty (RDP), and relative delay variation (RDV). The results indicate that our approach is a more reliable content delivery system when compared with contemporary methods in the context of heterogeneous networks containing wired and wireless environments.

Reliable multicast architecture based on multicast gateway

Guaranteeing the reliability of multicast communication is the premise of many applications based on multicast in Internet.Since it was difficult to deploy IP multicast on a large scale in Internet,the authors presented a Reliable Multicast(RM)architecture,which utilized multicast gateways to interconnect IP multicast islands and Application Layer Multicast(ALM)domain.Solutions to key points in the architecture,such as group identification,multicast gateway,group management,error control,and congestion control were also proposed.At the same time,a competitive algorithm for multicast gateway was designed.This architecture could shield the difference existing in underlying multicast techniques and thereby support uniform deployment of reliable multicast services in Internet.

A decentralised service composition approach for peer-to-peer video delivery

Recent platforms for Peer-to-Peer (P2P) based video distribution such as Zattoo and Joost are based on End-Host or Application Layer Multicast techniques. An on demand adaptation of audio/video data to end user terminals or to the transport and error characteristics of the client access technology is not supported. To address such issues in the scale of P2P Networks, we describe a cooperative service provisioning principle (CSP) based on the assumption that selected peers offer processing services to the community. In contrast to recent approaches our main focus in this paper is on the applicability of QoS estimation techniques to decrease time and measurement complexity of CSP. We provide a state of the art in landmark-based delay estimation and introduce a novel technique for landmark-based bottleneck bandwidth prediction showing favourable results for networks with widest path routing.

Optimization of layered multicast with network coding and genetic algorithm

This article studies the problem of constructing optimal layered multicast with network coding for heterogeneous networks. Based on the flexibility of layered source coding, a global-favorable optimization scheme is proposed, which maximizes the aggregate throughput of heterogeneous sink nodes for layered multicast with network coding by determining the optimal bit rates of the layers. To solve this global-favorable optimization scheme, especially in the large-scale heterogeneous networks, a new problem-specific genetic algorithm (GA) is further proposed. It not only searches efficiently for the optimal allocation of layer bit rates, but also guarantees the validity of candidate solutions in the whole evolutionary process. Simulation results demonstrate that this new GA-based optimization scheme could obtain efficiently the optimal or satisfactorily near-optimal bit rates for layered multicast with network coding, even in the large-scale heterogeneous networks.

MAC Layer Multicast Error Control for IPTV in Wireless LANs

Internet Protocol Television (IPTV) over IEEE 802.11 Wireless LANs, which are considered today as the de-facto wireless access network for local distribution (home networks, hotspots), brings forth a big challenge to guarantee high quality multicast/broadcast delivery over unreliable and time-variant wireless channels. However, in IEEE 802.11 Wireless LANs, current standard MAC layer protocols do not provide any error correction scheme for broadcast/multicast. In our previous work, we enhanced a Leader Based Protocol (LBP) and proposed a Beacon-driven Leader Based Protocol (BLBP) for the MAC layer multicast error control. However, as pure Automatic Repeat reQuest (ARQ) schemes, both LBP and BLBP are not efficient for large multicast groups. In this paper, we combine BLBP and packet level Forward Error Correction (FEC) and propose a Hybrid Leader Based Protocol (HLBP) for the MAC layer multicast error control. HLBP transmits the original data packets using raw broadcast and retransmits parity packets using an improved BLBP which is based on block feedback. To guarantee the required Packet Loss Ratio (PLR) under strict delay constraints for multicast delivery over a Gilbert-Elliott (GE) channel, we analyze LBP, BLBP and HLBP, develop analytic performance models that allow optimizing the configurations. The performance models are verified via simulation experiments. Both the theoretical analysis and simulation results show that HLBP is much more efficient than LBP and BLBP especially for large multicast groups and is also more efficient than the best application layer multicast error correction scheme. BLBP needs the minimum number of redundancy transmissions among all pure ARQ based schemes while HLBP needs the near-minimum number of redundancy transmissions among all schemes. Due to the simplicity and efficiency, BLBP is a good choice for IPTV multicast delivery for small groups in Wireless LANs while HLBP is a better choice for large multicast groups.

Application Layer Multicast Mechanism for Large-Scale Real-Time Streaming Media

PDF HTML阅读 XML下载 导出引用 引用提醒 面向大规模实时流媒体的应用层组播方案 DOI: 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: Supported by the National Natural Science Foundation of China under Grant Nos.60403035, 90604024 (国家自然科学基金); the National High-Tech Research and Development Plan of China under Grant No.2006AA01Z205 (国家高技术研究发展计划(863)); the National Basic Research Program of China under Grant Nos.2009CB320501, 2009CB320503, 2007CB307105 (国家重点基础研究发展计划(973)) Application Layer Multicast Mechanism for Large-Scale Real-Time Streaming Media Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:提出一种基于集中控制与分布式自组织相结合应用层组播方案:CD-Media.这种多层次的、稳定的组播方案在上层由能力较强且稳定的专用服务器组成星形结构,并由它们集中控制下层Mesh结构和组播树的构造与维护.下层应用层拓扑采用分布式的自组织协议.该方案分超节点、Cluster和组播岛3个层次,它们共同组成一棵组播树.这种“分层”、“分群”的思路提高了可扩展性,最大化提高网络可支持的用户数量,降低了成本,非常适合网络电视这种单源准实时应用.此外,为解决网络电视对稳定性要求高和应用层网络动态变化大之间的矛盾,Cluster内的应用层组播成员间采用全连通的Mesh结构,在此基础上由超节点集中计算组播树.CD-Media还将应用层组播与网络层组播相结合,充分发挥两者的优势.实验评价了CD-Media的性能,并与已有算法进行比较,结果显示该方案具有明显的优点. Abstract:An application layer multicast mechanism, CD-Media, is proposed based on the combination of central-control and distributed self-organization. This mechanism with different hierarchies is stable and suitable for the quasi-real-time application. Special servers with high performance is deployed in the higher levels to organize the star topology, and they are responsible for the construction and maintenance of Mesh network and multicast tree in the lower levels. In the lower levels a distributed protocol for self-organization is used and Mesh-first strategy is adopted in the Cluster. Multicast technologies both in application layer and network layer are combined to make use of their own advantages to achieve higher performance. An experiment is delicately designed to show the advantage of CD-Media, and it is convinced that it will be a promising mechanism in overly multicast. 参考文献 相似文献 引证文献

Outage performance of multi-antenna multicasting for wireless networks

Wireless cellular networks often need to convey the same data to multiple users simultaneously. This kind of transmission is known as physical layer multicasting. Unfortunately, when any user fails to receive the data correctly, the information must be retransmitted to all the users, resulting in a waste of radio resources. Thus, it is important to investigate the outage probability of multicast channels, which is defined as the probability that the smallest maximum achievable rate among all of the users is smaller than a specified transmission rate. In this paper, we consider the use of multiple antenna multicast channels where the transmitter is equipped with M <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sub> antennas and independent data is transmitted on each antenna to K users. Using extreme value theory, we derive a closed form limiting distribution that the exact distribution of the multicasting channel converges to when the number of users K is taken to infinity. From this result, we find upper and lower-bounds on the outage probability. It is shown that for a given outage probability the upper-bound becomes sufficiently tight to approximate the exact outage probability with K such that it converges to the exact one with a speed faster than Theta (K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1/M</sup> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sup> ). Using this upper-bound, we identify conditions on the transmission rate and the transmit power necessary to maintain constant outage performance as K increases. Specifically, the transmission rate should be decreased as Theta (K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1/M</sup> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sup> ) or the transmit power should be increased as Theta (K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/M</sup> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sup> ). This means that the outage performance improves as the number of transmit antennas increases, because spatial diversity can be well exploited. However, this increase in the number of transmit antennas requires a significant cost. To improve the performance without requiring additional cost, we consider a multiple-slot multicasting that transmits the same data over multiple slots and an antenna subset selection scheme that transmits the data over some subset of the transmit antennas. It is shown that the transmission rate of multiple-slot scheme can be increased when the number of slots is carefully chosen and the diversity-multiplexing trade-off is the same as that of K = 1. Also, the gain in the transmission rate from selecting some subset of the transmit antennas is derived.

An application layer multicast approach based on topology-aware clustering

Application layer multicast accelerates ubiquitous deployment of the multicast communication, as well as brings unavoidable performance penalties because the group members are dynamic and lack direct knowledge about the underlying topology. A promising approach to improve the multicasting performance is to cluster the nearby nodes in groups. However, it confronts some practical challenges. A challenge is that it is difficult to assign a proximity bound to determine whether some nodes should be clustered or not. Another practical problem is how to organize the corresponding multicast structure. In this paper, we propose a new topology-aware hierarchical clustering model, which implements clustering in different grain sizes. Based on the model, we propose an application layer multicast solution named HCcast, especially for large-scale group applications. HCcast employs a topology-aware approach to choose candidate parents at different levels, and uses distributed depth first searching (DFS) approach to position a host at the same level. The clusters of HCcast are topology-based, therefore cluster split and merge operations are unnecessary, which reduces the maintenance overhead. The results of our simulation experiments show that HCcast can build multicast trees with desirable delivery performance, and the performance keep stable in different join sequences.

All-optical router with pulse-position modulation header processing in high-speed photonic packet switching networks

In future high-speed photonic packet switching networks, it is highly desirable to carry out robust all-optical header recognition to provide high-throughput routing. The authors present a pulse-position modulation header processing (PPM-HP) scheme, offering significantly reduced routing table size and employing a single bit-wise AND operation to carry out correlation of the packet header with the entire routing table entries. The downsized routing table also offers multiple transmission modes (unicast, multicast and broadcast) in the optical layer and improves core network scalability where the number of core/edge nodes could be altered without the need for changing the number of routing table entries. The authors present modelling and simulation of the packet switching router based on PPM-HP. Noise propagation and crosstalk incurred in a multiple-hop routing scenario are investigated. The simulation results are presented and compared with the theoretical calculations.