Multicast Efficiency Research Articles

Efficiency of BIER Multicast in Large Networks

Bit Index Explicit Replication (BIER) has been introduced by the IETF to transport IP multicast (IPMC) traffic within a BIER domain. Its advantage over IPMC is improved scalability regarding the number of multicast groups. However, scaling BIER to large networks is a challenge. To that end, receivers of a BIER domain are assigned to smaller subdomains. To deliver an IPMC packet over a BIER domain, a copy is sent to any subdomain with a receiver for that packet. Consequently, some links may carry multiple copies of the same IPMC packet, which contradicts the multicast idea. In this paper, we propose and compare various algorithms to select subdomains for BIER in order to keep the overall BIER traffic low despite multiple packet copies. We apply them to investigate the traffic savings potential of IPMC and BIER relative to unicast under various conditions. We show that the traffic savings depend on network topology, network size, and the size of the multicast groups. Also the extra traffic caused by BIER depends on these factors. In spite of some redundant packets, BIER can efficiently reduce the overall traffic in most network topologies. Similarly to IPMC, BIER also avoids heavily loaded links. Finally, we demonstrate that BIER subdomains optimized for failure-free conditions do not cause extensive overload in case of single link failures.

Device-to-Device Communications Enabled Multicast Scheduling for mmWave Small Cells Using Multi-Level Codebooks

Heterogeneous cellular networks with small cells in the millimeter wave (mmWave) band densely deployed have become one of promising candidates for future wireless networks due to huge bandwidth available in the mmWave band. To overcome high path loss in the mmWave band, the beamforming technique of directional antennas is adopted. Consequently, concurrent transmissions of links can be enabled to improve network capacity. On the other hand, multicast services can support many applications like popular content downloading and broadcast communication services. In user intensive region where multicast services usually happen, device-to-device (D2D) communications in physical proximity provide better channel conditions, and can improve multicast efficiency. In this paper, we develop an efficient multicast scheduling scheme for mmWave small cells, referred to as CONMD2D, where both concurrent transmissions and D2D communications are exploited based on a multi-level antenna codebook to optimize network performance. In CONMD2D, the multicast group is partitioned into subgroups, and D2D transmission paths are established between subgroups. Then, a concurrent scheduling algorithm schedules the multicast links concurrently into the transmission stage. Performance evaluation under various system parameters demonstrates CONMD2D achieves significant improvement in network throughput and energy efficiency compared with other state-of-the-art schemes.

Efficient Community-Based Data Distribution Over Multicast Trees

Communities are important attributes of today’s networking, since people who join networks tend to join communities. Thus, community detection is an important issue in designing algorithms for delay-tolerant networks (DTNs). Multicasting is an appropriate method to share information within a community or between communities, because it delivers messages from a source to a group of targets using limited resources. This paper addresses the problem of detecting communities in weighted networks with irregular topologies. Based on communities, we propose an efficient data distribution algorithm for DTNs. The distribution strategy is based on the construction of a number of multicast trees, where each tree can be used to select the best relay node for each target to improve multicast efficiency. The proposed strategy provides better delivery ratio compared with other strategies and it reduces latencies when multiple nodes from a community need to multicast to other community members.

Adaptive Link Aware on-demand Multicast Routing Scheme in MANET

<em>The main objective of this paper is to propose a new multicast routing scheme to adopt with the dynamic topology of MANET at the same time to provide high multicast efficiency and packet delivery ratio. The proposed scheme is named as Link Aware on Demand Multicast Routing (LAOMR) scheme. In this scheme, initially the source node forms the multicast group by announcing itself as a multicast source agent to all the nodes in the network. The nodes which are eager to join in the group are sending the join request to the source node. Then the source node finds the route to reach the multicast group through some intermediate nodes. The intermediate nodes are not interested to hear the multicast message but they are act as the routers to forward the packets to the multicast group. The intermediate nodes are chosen based on the link residual life (LRL) of the nodes. The node which has the highest LRL and closer to the multicast group is selected as the forwarder node. So, the proposed scheme reduces the link failure in the multicast route and increases the multicast efficiency, throughput. The performance is evaluated by using the simulation results obtained from NS2 Simulator.</em>

Multicast-Based Optimized Peer Control for Efficient P2P Video Streaming in TDM-PONs

An important issue in network traffic management for Internet service providers (ISPs) is how to efficiently handle a large amount of data traffic generated by peer-to-peer (P2P) applications. This paper discusses the efficiency of P2P video streaming in time-division-multiplexed (TDM)-passive optical networks (PONs). We summarize the technical requirements that are required to efficiently serve P2P video streaming in the broadcast-and-select architecture of the TDM-PON. The proposed localized multicast-based P2P (LM-P2P) mechanism controls generation of P2P sessions adaptively based on information about the peer location and multicast efficiency in the optical line termination (OLT) domain. The centralized control node of LM-P2P selects a multicast seeder and recommends it to later clients as a seeder so that the amount of P2P streaming traffic can be minimized both in the inter-OLT domain and in the intra-OLT domain. The efficiency of LM-P2P in allocation of network resources is achieved by optimal migration of the property of P2P streaming on the unique architectural feature of TDM-PON. The efficiencies of typical P2P localization and P2P caching are compared with LM-P2P, and the systematic issues in localization of P2P sessions and management of multicast sessions are also discussed. The efficiencies of the proposed mechanism are validated by numerical analysis and practical test results.

Efficient Multicast Algorithms in Opportunistic Mobile Social Networks using Community and Social Features

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.

Link-Layer Multicast in Large-Scale 802.11n Wireless LANs with Smart Antennas

In wireless local area networks (WLANs), link-layer multicast is a promising technology for many multimedia applications, e.g., video streaming, as multicast frames can reach multiple clients simultaneously. However, the efficiency of multicast in WLANs is usually low since multicast frames are transmitted at a basic data rate to reach clients with poor channel quality. Moreover, the reliability of multicast cannot be guaranteed either, as multicast transmissions are not acknowledged. Some recent works have utilized smart antennas to improve multicast performance. However, most of them require customized hardware and are not designed for the latest IEEE 802.11 standard, 802.11n WLANs. More importantly, these works did not consider the impact of AP association strategies on the performance of link-layer multicast. In this paper, we study the problem of link-layer multicast in large-scale 802.11n WLANs where each AP is equipped with a smart antenna that supports multiple antenna patterns. Based on channel gains of various antenna patterns from different APs, we choose the associated AP for multicast clients, partition associated clients of each AP into multiple groups, select an antenna pattern and data rate for each group of client, and transmit multicast frames to each group once. We first examine the limitation of multicast in 802.11n WLANs and the benefits of smart antennas to multicast via experiments. We then introduce the system model and formulate the problem into an optimization problem, and prove its NP-hardness. The objective is to minimize the time to transmit a multicast frame to all clients while guaranteeing high packet reception ratio (PRR) for each client. For generic WLANs where APs are sparsely deployed, we propose an optimal algorithm under the condition that the PRR of antenna patterns and data rates are known for every client. For generic large-scale WLANs, we further propose an on-line algorithm in which the AP association strategy, the partition of clients, the antenna pattern and data rate of each group are adapted dynamically, based on PRR reports from clients. We have implemented the on-line algorithm on off-the-shelf WLAN products, and conducted extensive experiments and simulations to evaluate the performance. The results show that the proposed algorithm can significantly improve multicast performance compared to other schemes, and at the same time guarantee high PRR for all clients.

Determination of Efficient bandwidth utilization During Multicast using Data Envelopment Analysis

Data Envelopment Analysis (DEA) is an operational research tool that is used for measuring the performance efficiency of an algorithm or organization. In this paper, DEA is applied on the simulation results of an Improved Network Coding Algorithm (INCA) with two and three performance in order to establish the performance efficiency of the two algorithms in terms of bandwidth utilization during video conferencing over a wireless network. Most researches which focus largely on determining the effectiveness of the INCA in terms of bandwidth consumption during video conferencing. However, this approach which uses DEA, the simulation results showed that the INCA with two parameters is the most cost-Efficient algorithm in terms of performance than the INCA with three parameters. General Terms Data Envelopment Analysis, Improved Network Coding Algorithm, Multicast and Performance Efficiency.

Coordinated Multicasting With Opportunistic User Selection in Multicell Wireless Systems

Physical layer multicasting with opportunistic user selection (OUS) is examined for multicell multi-antenna wireless systems. In multicast applications, a common message is to be sent by the base stations to all users in a multicast group. By adopting a two-layer encoding scheme, a rate-adaptive channel code is applied in each fading block to enable successful decoding by a chosen subset of users (which varies over different blocks) and an application layer erasure code is employed across multiple blocks to ensure that every user is able to recover the message after decoding successfully in a sufficient number of blocks. The transmit signal and code-rate in each block determine opportunistically the subset of users that are able to successfully decode and can be chosen to maximize the long-term multicast efficiency. The employment of OUS not only helps avoid rate-limitations caused by the user with the worst channel, but also helps coordinate interference among different cells and multicast groups. In this paper, efficient algorithms are proposed for the design of the transmit covariance matrices, the physical layer code-rates, and the target user subsets in each block. The system parameters are determined by maximizing the group-rate in the single-group scenario and by considering a group-rate balancing optimization problem in the multi-group scenario. To further reduce the feedback overhead, we also consider the case where only part of the users feed back their channel vectors in each block and propose a design based on the balancing of the expected group-rates.

An Effective Multicast Stream Scheduling Mechanism in Passive Optical Networks

In this paper, an effective multicast stream scheduling mechanism in PON is proposed. The weights of buffered queues in the SCB port of OLT are calculated based on the multicast efficiency, aiming to achieve maximized effective multicast throughput. Simulation results confirm that the proposed mechanism can obtain better performance than previous method when system is heavy loaded.

Micro Base Station Aided Failover for Multicast Scheduling in Wireless Cellular Networks

We consider scheduling mechanisms for downlink multicasting of critical messages across cellular wireless systems. We study the robustness of such schemes following the failure of a macro base station (MBS) node. We determine whether the additional deployment of micro base station (mBS) nodes can enhance the system's performance. We assume MBS and mBS nodes to coordinate their multicast transmissions by using TDMA or FDMA (rather than an MBSFN-based) adaptive rate and power scheduling algorithms. Neighboring mBS and MBS nodes coordinate their operations to optimally configure their transmission schedules and spectral and/or temporal resources and transmit code rate and power levels. We show that, under low intersite distance (ISD) values, each identifying the distance between neighboring MBS nodes, the use of deployed mBS nodes does not enhance the system's attainable multicast spectral efficiency. Under intermediate ISD levels, the deployment of a backup mBS node that is located near the MBS node limits the post-failure degradation of throughput capacity rate to less than 10%. In turn, under longer ISD range levels, the combined use of a backup mBS and of neighboring mBS nodes, which adjust their code rate levels to reach mobiles located in the failed cell, leads to significant performance improvement.

An Advanced AOI-Cast Algorithm Based on PCA

Voronoi-based Overlay Network (VON) has been proposed that promises to maintain high overlay topology consistency in a bandwidth-efficient manner. VoroCast constructs a spanning tree across all AOI neighbors based on Voronoi diagrams, while FiboCast dynamically adjusts the messaging range by a Fibonacci sequence. VoroCast improves the AOI scalability of P2P-based NVEs. However, one potential drawback of the schemes is that the child node degrees are only based on peers' positions, but not node capacities. Since each node in VoroCast has different capacity, packet loss will be unavoidable. VoroCast may lead to lower multicast efficiency in AOI. To these problems, an Advanced AOI-cast algorithm based on PCA is presented. In the algorithm, node capacity is related to node CPU (c), node bandwidth (b) and node memory (m), and the node capacity is calculated according to the PCA. An undirected graph is formed through all the nodes in the AOI and the edge weights are calculated by the Gaussian function. Through the prim algorithm, to generate the minimum spanning tree of the weighted undirected graph, and the minimum spanning tree is used as the final multicast tree. The message is delivered through the multicast tree. The simulation results show that the algorithm gains a greater improvement on multicast efficiency, and achieves better scalability.

Adaptive Packet Transmission Scheduling Using Multicast Service Efficiency in TDM-PON

In this paper, transmission scheduling issues related to multicast traffic, which focus on multicast service efficiency, are discussed for downstream packet transmission of a time-division-multiplexed passive optical network. First, the features of multicast traffic-sharing and the effects on multicast efficiency are analyzed in detail. Second, metrics, which are utilized in the measurement of multicast service efficiency, are introduced, and two kinds of fairness issues in multicast packet transmission are defined. Finally, an adaptive multicast packet transmission scheduling mechanism, called multicast-share weighted fair queuing, is proposed in order to stably guarantee fair amounts of effective throughputs to multicast sessions according to changes in the multicast service efficiencies of sessions. Analytic and simulation results confirm that the proposed mechanism guarantees the inter-session fairness in terms of effective throughput efficiently.

Lcast: Software-defined inter-domain multicast

Traditionally, efficient inter-domain data delivery may be implemented either as a network or as an application layer multicast service. However, while the former has seen little uptake due to prohibitive deployment costs the latter is widely used today, but often without a minimum guaranteed performance. In this paper we present Lcast, a network-layer single-source multicast framework designed to merge the robustness and efficiency of IP multicast with the configurability and low deployment cost of application-layer overlays. The architecture involves no end-host changes and only requires the upgrading of a small set of routers to support the Locator/ID Separation Protocol (LISP), an incrementally deployable enhancement to the current global routing infrastructure. Content distribution over the Internet’s core is done by means of a router overlay while within domains, end-hosts interface with Lcast using conventional multicast protocols. The overlay’s scalability and topological configurability is sustained by logically centralizing group management. We illustrate the versatility of our solution by designing and assessing the scalability and performance of three management strategies for low latency content distribution. Our analysis is based on large scale simulations supported by realistic user behavior and Internet-like network topologies. The results show Lcast’s low management overhead and ability to optimize delivery to meet various operational constraints. Notably, we find that it can deliver traffic with latencies close to unicast ones, independent of overlay size.

An Advanced P2P Multicast Algorithm Based on Scribe

This paper presents an advanced multicast algorithm to the question of low multicast efficiency and poor game states synchronization in the SCRIBE algorithm based on P2P for MMOG. This algorithm constructs a multicast tree mainly considering node heterogeneity on bandwidth resource, computing resource and storage resource, moreover it approximately balances multicast tree by looking for a sub-tree which its high is lower. The experiment results show this algorithm can reduce message redundancy and multicast delay to a greater extent, and greatly improve game state synchronization.

Multicast Gain for IPTV Transmission in WiMAX Multi-hop Relay Networks

Due to characteristics such as: multicast support, wide coverage range, high bandwidth and mobility support, WiMAX could be a leading solution to deliver bandwidth-hungry IPTV services to mobile users. Mobile multi-hop relay (MMR) was proposed as an amendment of the current mobile WiMAX standard to provide relaying capabilities. Relays are deployed as a cost-effective solution to extent coverage area and increase throughput without deploying expensive base stations. In this paper, we introduce multicast gain as a performance criterion, which can be used for computing multicast efficiency. In order to quantify the benefits of multicasting, we analyze multicast transmission for delivery of live TV channels in MMR networks, and determine the gain of access and relay links. The quantification of the efficiency of multicasting can be used by IPTV service providers in resource provisioning, access control or decision support mechanisms in delivery of different TV channels.

Layered video multicast using fractional frequency reuse over wireless relay networks

Nowadays, multimedia services over wireless networks are increasingly popular. With multicast, many mobile stations can join the same video group and share the same radio resource to efficiently increase frequency utilization. However, users may be located at different positions, and so suffer different degrees of path loss and interference, and receive a different signal-to-interference and noise ratio (SINR). Users at the cell-edge receiving a lower SINR may degrade the multicast efficiency. In this article, we propose four schemes that consider fractional frequency reuse (FFR) over relay networks in multi-cells. With FFR, users close to a base station (BS) are given more resources to improve the video quality. An efficient resource allocation scheme is also proposed. Compared to the conventional relay scheme, the proposed schemes can provide over 10% more video layers for all users and give better video quality for users near the BS.

Practical service level agreement negotiation scheme for multicast service in WiMAX

For multicast service in WiMAX, there are trade-offs between overall channel efficiency and the number of users under the commitment of service level agreements (SLAs). So, it is important to compromise between accommodating many users under the commitment of SLA and channel efficiency. In order to give an insight of multicast efficiency, we suggest a novel metric which is named as channel efficiency (MCE) factor. In addition, we proposed the practical SLA negotiation scheme based on proposed novel metric. Numerical results show that the proposed practical scheme significantly outperforms the conventional multicast transmission scheme.

Hierarchical multicast in wireless sensor networks with mobile sinks

AbstractIn most studies of wireless sensor networks (WSNs), sensor nodes and sinks are typically stationary. However, mobile sinks are required in various applications of real‐life environments, and delivering sensed data to mobile sinks using ordinary routing protocols is very inefficient. Multicasting is an important process in the minimization of the number of transmissions in WSNs. Since sensor nodes have limited resources, many studies have focused on how to send data to specific receivers efficiently. This work presents a grid‐based hierarchical multicast (HM) routing protocol for WSNs with mobile sinks. Location servers (LSs) are adopted to manage the information about the locations of receivers and then a multicast tree is constructed distributively to reduce the update cost and energy consumed by sink mobility. The multicast tree can be shared by multiple sources, reducing the path construction overhead. Furthermore, effective maintenance mechanisms that make the multicast tree more stable and robust are presented. Finally, the performance of the proposed HM is investigated by simulation. Simulation results demonstrate that the proposed protocol has a lower energy consumption and higher multicast efficiency than distributed multicast routing protocol (DMRP) and hierarchical geographic multicast routing (HGMR), especially when many sources and receivers are involved. Copyright © 2010 John Wiley & Sons, Ltd.

On predictable large-scale data delivery in prefix-based virtualized content networks

IPTV, software replication, and other large scale content distribution services raise the need for fast and efficient content delivery mechanisms in underlay as well as overlay networks. Multicast, the natural approach on the network layer, has not been deployed globally, and solutions are pushed to the application layer. For a flexible, sustainable deployment the distribution mechanisms in use should scale up to many thousand group members and provide predictable performance to dynamically adjust to actual performance requirements. In this paper, we present a rigorous analytical model complemented by extensive simulations for content delivery on prefix-based overlay trees. We examine BIDIR-SAM, a generic multicast distribution scheme guided by prefixes that allow for late next-hop binding. Our evaluation quantitatively substantiates all major performance aspects. We derive the distribution functions of hop counts, packet replication loads, as well as all relevant cost measures, which scale logarithmically with network and receiver sizes. Prefix-based content delivery exhibits a churn resistance similar to the underlying key-based routing layer and a multicast efficiency scaling factor close to native group communication protocols. These results make the approach especially suitable for large and very large content groups.