A Pragmatic Semantic Reliable Multicast Architecture for Distance Learning

IEEE 802.16j Mobile Multihop Relay Standard defines multi-hop relay operation in a WiMAX system. It uses a novel synchronous multicast and broadcast transmission mechanism to achieve macro diversity. With the newly introduced synchronous delivery constraint, the multicast data delivery algorithm should be designed differently to enhance system performance. This paper provides Multi-Rate Selection Algorithm (MRSA) for multicast and broadcast (MBS) data delivery. It could reduce the data distribution delay from the BS to all the RSs. Besides, we also propose the path selection algorithm to further improve the effectiveness of MRSA. Our simulation results show that using MRSA with our shortest-path path selection algorithm, the delay for data delivery in 802.16j MBS system could be greatly reduced. The proposed scheme could achieve the performance closed to the optimal solutions. To the authors' best knowledge, this is the first research work to investigate the IEEE 802.16j multicast and broadcast problem.

Relay-based multipoint content delivery for wireless users in an information-centric network

P2P (Peer-to-Peer) file sharing architectures have scalable and cost-effective features. Hence, the application of P2P architectures to media streaming is attractive and expected to be an alternative to the current video streaming using IP multicast or content delivery systems because the current systems require expensive network infrastructures and large scale centralized cache storage systems. In this paper, we investigate the P2P progressive download enabling Internet video streaming services. We demonstrated the capability of the P2P progressive download in both laboratory test network as well as in the Internet. Through the experiments, we clarified the contribution of the FTTH links to the P2P progressive download in the heterogeneous access networks consisting of FTTH and ADSL links. We analyzed the cause of some download performance degradation occurred in the experiment and discussed about the effective methods to provide the video streaming service using P2P progressive download in the current heterogeneous networks.

The fast development and deployment of the Internet and mobile communication has boosted personal computing and communication. The ever-increasing number of personal devices accessing the Internet demands IP mobility support ubiquitously. However, the current TCP/IP protocol suite is not able to fully support IP mobility, especially when real-time applications are concerned. This paper discusses the IP mobility support in general and IP multicast receiver mobility support in particular. The current Internet is capable of providing basic mobility support for IP multicast when mobile hosts act as IP multicast receivers. However, the worst case handover latency introduced by IP layer handover is usually unacceptable to the real-time applications running in the mobile receivers. In order to overcome this, we propose a Mobility Support Agent (MSA) architecture and a set of protocols to help achieve seamless IP multicast mobility. Our testbed runs IGMPv2 and PIM-SM. Measurements have shown that by using the MSA architecture, the handover latency introduced by the current multicast membership management protocols and multicast routing protocols is nearly negligible.

In this paper, we propose a multimedia streaming scheme by using the proposed N-screen resource allocation and N-screen DRP Availability Information Element, for n-screen service in Wearable health-monitoring systems (WHMS) networks. The proposed scheme can improve throughput performance of WHMS Vital Video (WVV) applications. Also, proposed scheme can reduce WVV delay since it minimizes the multicast WVV data delivery process. Compared with the legacy WHMS system, the proposed streaming scheme is very simple and efficient as it does not require additional hardware. These merits make the proposed WHMS system extremely inexpensive to implement in hospital WHMS network and bio cloud-computing applications.

Since the deployment of IP multicast remains restricted due to many practical and political issues, researchers have shifted focus to exploiting application-layer multicast for multicast data delivery. Recently there has been considerable interest in applying DHT routing algorithms to application-level multicast. However, early DHT-based multicast protocols are insufficient in addressing a number of technical issues such as heterogeneous capacity of nodes or node churn. In this chapter, the author describes a solution called BAM-Chord (i.e., Bandwidth Adaptive Multicast over Chord) that optimizes the topology of a multicast tree based on node bandwidth. In the proposed solution, node position (i.e., node identifier) on a BAM-Chord ring will be decided based on node bandwidth capacity such that it can build a wide and balanced multicast tree rooted at the source node. As a result, BAM-Chord protocol can utilize network resources of every node to reduce the depth of the multicast tree and take advantages of DHTs in maintaining the multicast tree.

Satellites are expected to have an important role in providing the Internet protocol (IP) multicast service to complementing next-generation terrestrial networks. In this paper, we focus on the deployment of IP multicast over the next generation of digital video broadcasting-based geosynchronous earth orbit satellites supporting multiple spot beams and on-board switching technologies. We propose a new encapsulation scheme optimized for IP multicast, which has two distinct modes enabling two alternative on-board switching approaches: the self-switching and the label-switching. We also detail a set of mechanisms and protocols for ground stations, as well as for the on-board processor to allow an efficient multicast forwarding in this type of environment, while reducing the load of control and data messages in the satellite segment, and building efficient multicast delivery trees reaching only the spot beams containing at least one member of the corresponding multicast session. To integrate satellite links in the terrestrial Internet, we present satellite multicast adaptation protocol (SMAP), a protocol which is implemented in satellite stations to process incoming protocol independent multicast-sparse mode (PIM-SM) messages sent by terrestrial nodes to the satellite system. SMAP helps to update the tables required for the mapping between IP packets and MPEG-2 data segments, their switching on board the satellite, and their filtering at the satellite receivers.

IP multicast dictates high-end routers and incurs high administrative overhead, which prevent them from being deployed in many video streaming scenarios. In this paper, we study the problem of computing the multipath multicast routes for streaming videos in Software-Defined Networks (SDNs), which adopt less expensive switches and reduce administrative overhead for lower CAPEX/OPEX. The objectives of the considered problem are robustness, load balance, SDN compatibility, and adaptiveness. We formulate this routing problem into a mathematical optimization problem, and propose two algorithms to address this problem. We implement the proposed algorithms on a popular OpenFlow controller to demonstrate its practicality, and we conduct extensive experiments to evaluate the proposed algorithms. The experiment results clearly show the merits of our algorithms over the IP multicast, e.g., we observe: (i) frame loss rate reduction between 19% and 95%, (ii) video quality improvement between 4 dB and 15 dB, (iii) sink throughput increase between 25% and 66%, and (iv) maximal link utilization reduction between 15% and 50%. We also show the tradeoff between optimality and run time of the two proposed algorithms: one of them is more suitable for smaller and more static networks, and the other one is more suitable for larger and more dynamic networks.

IP multicast was initially designed for stationary members and does not consider extra requirements for mobile parties. In fact, to deploy IP multicast, two essential components are required: a membership management protocol to manage the join/leave process, and a routing protocol to build the multicast delivery tree. Currently, multicast membership protocols such as IGMPv3 and MLDv2 rely on a periodic forwarding model between the Querier and the receivers. However, when dealing with mobile IP receivers, the periodic queries prohibit mobile hosts from using sleep mode to conserve battery power when no multicast traffic is present. In addition, the home agent (HA) has to implement the IGMP/MLD forwarding functions, and to tunnel periodically membership messages to all remote mobile receivers, which induces a significant processing overhead. To solve this problem, we propose an adaptive solution in which the HA does not periodically transmit membership messages to mobile receiver. We prove by simulation that our solution reduces significantly the amount of membership messages sent through the mobile IP bi-directional tunnel

In the current Internet, there is a real need for the online real-time traffic identification technique to provide different services for real-time and bulk applications. Previously, it is easy to identify real-time traffic by checking the protocol/port number in IP header, however, it becomes more difficult due to the existence of real-time traffic over TCP connection, P2P and VPN. Previously, we have proposed the online identification method based on flow statistics without checking the protocol/port number to solve these problems. However, this technique performance is unstable due to environment dependency. In this paper, at first, we reanalyze the characteristics of bulk and streaming traffic flows, which shows that the packet arrival interval varies significantly among high-bitrate, low- bitrate and bulk flows. Second, we propose a new identification method without using a fixed threshold depending on network environment. Finally, testing shows that its identification accuracy is higher than that of a previous method, which recognizes only two types of flows. It also shows that the improved method is robust against differences in the network environment.

The coexistence of human type communications (HTC) with an ever-increasing number of machine type communications (MTC) is a challenge that the forthcoming Fifth Generation (5G) network is claimed to tackle. Ultra-Reliable and Low Latency Communications (URLLC) are among the most demanding services that 5G network will support. Also referred to as mission-critical services, URLLC often requires group communications. The evolved Multimedia Broadcast and Multicast Services (eMBMS) architecture, currently specified by 3GPP to support group-based services in cellular networks, needs a revision to deliver future mission-critical services. In this paper, we analyze the performance of different machine-type multicast service (MtMS) scenarios and we compare three subgroup based approaches for multicast data delivery to MTC devices with limited channel bandwidth. Achieved simulation results provide useful guidelines for the design of multicasting schemes able to support delay-sensitive applications in 5G networks.

TCP slow start with fair share of bandwidth

In this paper, we introduce Relayed Multicast Control Protocol (RMCP). The RMCP has been designed for realizing and managing the relayed multicast. Relayed multicast, as known as Overlay Multicasting or Application-level Multicasting, is a data delivery scheme for one-to-many multicast application, in which one or more intermediate Multicast Agents are employed for relaying application data from a sender to many receivers along a tree hierarchy. In RMCP, a special-purpose entity, named Session Manager, is used to manage the overall control operations. RMCP is designed to ensure that the multicast applications and services can be provided along with the associated relayed data transport schemes over current Internet environments in which IP multicast has not completely been deployed.

Peer-to-peer (P2P) streaming is attracting much attention. It requires neighbor selection to construct an overlay and delivers streaming data on it. Therefore, neighbor selection determines the performance of P2P streaming system. There is obvious heterogeneity of bandwidth and latency in current Internet. However, there is still a lack of neighbor selection approach suited for heterogeneous P2P streaming. Most current neighbor selection methods do not consider the heterogeneity or do not consider bandwidth and latency simultaneously. In this paper, we propose a new QoS driven neighbor selection method derived from the Metropolis-Hastings algorithm. The main contribution of this paper is: i) we put forward a new metric for the first time, called bandwidth latency ratio (BLR), which is a tradeoff between bandwidth and latency. We testify the effectiveness of BLR on evaluating QoS sensitive P2P streaming system. Our neighbor selection could optimize the distribution of peers' BLR; ii) in heterogeneous environment, our approach could effectively improve the QoS of peers' neighbors, which will enhance the transmission performance and user experience of P2P streaming system. We provide theoretical analysis of our method's improvement in terms of BLR, compared with SCAMP. Simulation results also demonstrate that the throughput, packet delay and playback quality of the P2P streaming system with our neighbor selection can be significantly improved.

This paper introduces the multicast communication model based on TCP/IP protocol, explicates the support for IP multicast by Winsock 2, designs and realizes the activity image IP multicast system in the local area network environment.