NGL01-4: A Hybrid GRASP with Data Mining for Efficient Server Replication for Reliable Multicast

In multihop wireless networks, many applications require end-to-end reliable multicast communication with 100% packet delivery ratio. Recently, network coding has been applied to the reliable link-level multicast in wireless networks, where multiple lost packets with distinct intended receivers are XOR-ed together as one packet and forwarded via single retransmission, resulting in a significant reduction of bandwidth consumption in the scenarios of many receivers. However, the simple XOR operation cannot fully exploit the potential coding opportunities. Moreover, for the reliable multicast in multihop wireless networks, the number of receivers of link-level multicast is usually not large and thus this coding-based link-level multicast cannot provide a promising gain. In this work, we propose a new network coding-based reliable multicast scheme which exploits both network coding and the physical-layer broadcast nature. Specifically, first, at each link-level multicast the source node performs the more general coding operations instead of XOR and conducts the random linear packet coding such that more coding gain can be achieved. Second, each node snoops on all communications over the wireless medium and stores the overheard packets for packet decoding, such that an additional coding gain can be obtained. Extensive simulations demonstrate that the proposed scheme can greatly improve the transmission efficiency, especially in the case of large-group multicast.

This thesis focuses on exploring a multicast communication protocol forWiFi Direct (WD) 802.11 networks. The aim is to improve reliability and efficiency of multicast communication in WD networks. Multicast inWDhas numerous potential applications such as local content sharing, sharing network services, playing multi-player games, and a number of other proximity based services in various fields, viz. health, sports, agriculture, transportation, and gaming. The two major issues with multicast, reliability and efficiency, have been extensively studied in literature for standard WiFi 802.11 networks. However, multicast protocols used in standard WiFi 802.11 networks cannot be straightforwardly used in WD networks because the two technologies are different. Some of these differences include multicast group formation, group architecture, network topology, role and capacity of multicast transmitter. As a result, a multicast protocol cannot achieve reliability and efficiency without taking into account the specifications of the MAC and PHY layers of WD 802.11 networks. Motivated from the leader based approaches of standard WiFi, an Enhanced Leader Based Multicast (ELBM) protocol is proposed to achieve reliability in multicast communication in WD networks. It reduces collision and interference in multicast data transmission by improving the channel access mechanism and selecting an optimal representative multicast receiver. In order to assess the performance improvement which results from early detection of packet collision, Early Packet Loss Detection (EPLD) analytical model is proposed, which surpasses the standard protocol in terms of system throughput. Similarly, a theoretical model is formulated to investigate the new features of the MAC and PHY layers of 802.11ac, such as different Multiple In Multiple Out (MIMO) configurations, Modulation and Coding Schemes (MCS), and wider channel bandwidths under TGn channel models. Because hidden nodes can largely affect the throughput of WD networks, therefore an improved analytical model known as Vidden is developed to analyse the Very High Throughput (VHT) of 802.11ac in the presence of hidden stations. Vidden carefully calculates the collision probability by taking into account both the contending, as well as, the hidden stations A novel adaptive algorithm is proposed to maximize the efficiency of WD 802.11 networks under a TGn channel model by choosing optimal PHY parameters in accordance with targeted Quality of Experience (QoE) for a particular application. The simulation results show that the proposed method outperforms the standard method, thereby achieving an optimal performance in an adaptive manner. Thereafter, an efficient methodology is proposed to reduce the overall Packet Error Rate (PER) based on the simulation results. Finally, the problem of selecting the most favourable transmission channel and rate is investigated for a multicast communication system in the context of WD 802.11 networks. To this end, a novel Multi-rate Multi-channel Multicast (M3-Cast) protocol is proposed, which not only chooses the most favourable communication channel and transmission rate but also takes into account the implementation details of the underlying WD technology, thereby optimizing the overall system performance. M3-Cast is formulated analytically and evaluated by a complete system level simulation. The detailed results and analysis consider a number of performance metrics, such as bit error rate (BER), multicast capacity, and system throughput under different MIMO configurations, channel bandwidths, and various network radii. Consequently, the simulation and analytical results show that M3-Cast protocol outperforms the standard multicast protocol of WD by almost two-fold in terms of system throughput.

An attempt is made to realize highly reliable multicast communications without modifying the TCP protocol, which is now the most widely used in the Internet, and TCP multicast using a GRA (generic router assist) router is proposed. The characteristics of this multicast communications are evaluated, and it is shown that the overall throughput of multicast communications is governed by the bottleneck link in the transmission band. An attempt is made to improve the performance of multicast communications with a bottleneck link, and an environment‐adaptive multicast communication scheme is proposed, in which the multicast tree is partitioned at the bottleneck link, and TCP multicasting is performed for each subtree. Performance evaluation by simulation shows that the proposed method alleviates the effect of the bottleneck link on the overall multicast and that the performance of the multicast as a whole can be improved. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(3): 28–38, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10161

AS businesses become more dependent on IP networks, lots of real-time services are adopted and high availability in networks has become increasingly critical. With the development of carrier grade ethernet, the requirements of high speed metro ethernet device are more urgently. In order to reach the capacity of hundreds of Gbps or Tbps, most of core ethernet switches almost adopted distributed control architecture and large capacity forwarding fabric. When distributed switch works, they always have one CE and many FE. There for, it shows the feature of multicast with one sender and many receivers. It is deserved research for us how to apply reliable multicast to distributed switch inner communication system. In this paper, we present the general architecture of a distributed ethernet switch, focusing on analysis the model of internal communication subsystem. According to its character, a novel reliable multicast communication mechanism based on FEC recovery algorithm has been applied and evaluated in experiment.

Conferencing applications require an efficient conference control service. This paper introduces the main features of a conference control service based on the CORBA event service using the Java platform, under development at the Communications and Telematic Services Group of the University of Coimbra. This framework is based on the ITU T.120 recommendations, with reliable multicasting communication for both data and control information. The control service extends the CORBA Event Service architecture with mechanisms for reliable IP multicast communication, with total ordering of the events transmission, filtering and fragmenting/reassembling of large messages.

OMG has published an unreliable multicast specification for distributed applications developed in CORBA (UMIOP). This mechanism can be implemented based on IP Multicast, a best-effort protocol, which provides no guarantees about the message delivery. However, many fault-tolerant or groupware applications demand more restrictive agreement and ordering guarantees (for instance, reliable multicast with FIFO, causal or total ordering) from the available support for group communication. OMG has not yet provided any specification for supporting those requirements. This paper presents an important contribution towards this direction. We proposed the ReMIOP, an extension to the UMIOP/OMG protocol, for the conception of a reliable multicast mechanism in CORBA middleware. Performance measures comparing ReMIOP, UMIOP and UDP sockets for IP multicast communication are presented in order to evidence the costs for adding reliable and unreliable multicast in middleware level.

Multicast Communications in Next-Generation Internet

The demand for efficient IoT firmware update protocols is increasing. Especially in scenarios with a large number of constrained devices, transferring a big amount of data, like a firmware image file, over a constraint network takes a long time to complete. During this time the functionality of the devices may be reduced. Therefore the firmware update is a critical use case for IoT. Multicast group communication can shorten the transmission time and use the network bandwidth efficiently. However, current IoT protocols using multicast cannot guarantee reliability which is most important for firmware file transmission. Furthermore existing solutions for reliable multicast cause a significant network overhead which can be prohibitive for a constrained IoT environment. To address these problems, we propose a reliable multicast solution employing a Negative ACK (NACK) mechanism that can be integrated with the Constraint Application Protocol (CoAP) widely used in IoT. Our protocol mitigates network congestion by reducing the number of packets that have to be sent while keeping the message size small making it a suitable solution even with a large number of devices. What is more, our proposal does not require an additional stack. In order to demonstrate the feasibility and effectiveness of our proposal, we carried out a real-world evaluation in a wireless mesh network testbed.

The practical use of IP multicast is starting on the Internet with the development of many reliable multicasts in recent years, and it is supposed that IP multicast will spread rapidly in the near future. At that time, congestion of multiple multicast traffics will occur in a certain network. But the service quality in such a case has not been made clear. Then, we evaluated the reliability of multicast traffic under the congestion of multiple multicast traffics including reliable multicast traffic using an experimental network. In this paper, we present the evaluation results of the experiment, and propose a reliability control scheme applied with QoS technique for improving reliability.

Building on the success of unicast IP, IP Multicast adopted a simple, open, best-effort delivery model with many-to-many semantics. Despite several years of effort, a general, scalable and reliable end-to-end transport protocol analogous to TCP has proven elusive. Proposed solutions are either inflexible, or incur high control overhead. We present Lightweight Multicast Services (LMS), which enhance the IP Multicast model with simple forwarding services to facilitate scalable and efficient (compared to pure end-to-end) solutions to problems such as reliable multicast. In LMS, routers tag and steer control packets to preselected endpoints and perform fine-grain multicast to guide responses to a subset of the group without transport-level processing. LMS divides error control into transport and forwarding components, which allows the former to remain at the end-points while the latter is pushed to the routers, where it can be implemented very efficiently. The division is clean, resulting in significant gains in performance and scalability, while reducing application complexity. LMS reaches beyond reliable multicast to applications such as scalable collect, any-cast, and in general, any application that can benefit from a hierarchy congruent with the underlying topology.

Problem statement: Multicasting communication network accepted a single message from an application and delivered copies of the message to multiple recipients at different locations. Recently, there has been an explosion of research literature on multicast communication environment. The objective of this study were to contribute the complexity of supporting current multicast applications, (i) the lack of reliable multicast transport mechanisms at the network level and (ii) the lack of network support for large scale multicast communication. The scaling problem of secure multicast key distribution compounded for the case where sender-specific keys need to be distributed to a group and required for sender-specific authentication of data traffic and minimize control overhead (iii) compare RC4, AES-128,RS(2) and RS(3) computation time of both algorithms. Approach: Algorithms were collected and performed computation time. In general the multicast key distribution scheme implemented for distributing 128 bit session keys. Thus the Maximum Distance Separable Codes (MDS Codes) needed for their encoding and decoding process. In rekeying scheme errors were occurred during over period of time or at a particular point of time and to eliminate all these errors in the level of encryption and decryption mechanism. The MDS codes played an important role in providing security services for multicast, such as traffic, integrity, authentication and confidentiality, is particularly problematic since it requires securely distributing a group (session) key to each of a group’s receivers. Results: First we showed that internet multicasting algorithms based on reverse path forwarding were inherently unreliable and present a source-tree-based reliable multicasting scheme also. The new scheme proposed and used as an inter-gateway protocol and worked on top of the previously developed distance vector and link state internet routing schemes. Next, to support large scale applications, we presented a scheme for partial multicasting and introduced a new network level operation, called gather. The partial multicasting mechanism allowed messages to be delivered to subsets of multicast destinations, while the gather operation aids gateways in selectively suppressing redundant messages, thus reducing the message complexity. Conclusion: Hence the findings suggested the control overhead reasonably minimized and using simulations, we investigated the efficiency of our schemes in supporting scalable application domain based multicast communication.

In reliable multicast, data packets can be cached at some nodes such as repair servers for future possible retransmission in loss recovery schemes. How to cache packets to optimize the performance of loss recovery is an important issue in reliable multicast protocol design. In this paper, we present a general solution which addresses the main design problems of caching policies. We first formulate the caching policy design as an optimization problem by employing caching utility as a uniform measure. Based on caching utility, we propose an algorithm called Optimal Caching Time (OCT) for configuring the caching time of packets and demonstrate that it solves the optimization problem. Furthermore, we analyze the performance improvement of OCT caching policy compared to the existing caching policies such as FIFO, Probabilistic FIFO (P-FIFO), and Timer-Based Caching Policy (TBCP). We use ns-2 simulations to demonstrate the performance gains brought by OCT caching policy. The numerical results show that OCT caching policy improves the performance significantly, especially for heterogeneous groups of receivers. With the inherent generality of the proposed model and the OCT algorithm, they can be easily applied to the general cache design in reliable unicast or multicast applications, and in both wired and wireless networks.

Multicasting plays an important role in internet networks. Supporting wavelength division multiplexed (WDM) multicasting in an IP over WDM network poses interesting problems because some WDM switches may be incapable of switching an incoming signal to more than one output interface. Although some multicast applications, such as audio/video conferencing can tolerate packet error or loss, other applications such as one-to-many file transfer and military applications do not. Hence, an inevitable need for reliable multicasting arises. The reliable multicast protocol ensures the eventual delivery of multicast data to all multicast group members. The reliable multicast is receiver initiated NACK-based and it makes use of feedback suppression in order to avoid NACK and retransmission implosion. The loss recovery burden is distributed over the multicast group members in order to reduce recovery latency and end-to-end delay. The proposed protocol is evaluated in terms of performance metrics for an IP/WDM optical network which will be the candidate for the next generation internet networks.

Multicast in wireless sensor networks (WSNs) is an efficient way to spread the same data to multiple sensor nodes. It becomes more effective due to the broadcast nature of wireless link, where a message transmitted from one source is inherently received by all one-hop receivers, and therefore, there is no need to transmit the message one by one. Reliable multicast in WSNs is desirable for critical tasks like code updation and query based data collection. The erroneous nature of wireless medium coupled with limited resource of sensor nodes, makes the design of reliable multicast protocol a challenging task. In this work, we propose a time division multiple access (TDMA) based energy aware media access and control (TEA-MAC) protocol for reliable multicast in WSNs. The TDMA eliminates collisions, overhearing and idle listening, which are the main sources of reliability degradation and energy consumption. Furthermore, the proposed protocol is parametric in the sense that it can be used to trade-off reliability with energy and delay as per the requirement of the underlying applications. The performance of TEA-MAC has been evaluated by simulating it using Castalia network simulator. Simulation results show that TEA-MAC is able to considerably improve the performance of multicast communication in WSNs.

Having reliable communications during large-scale emergency situations is of paramount importance in today's world. In particular, broadcasting critical information to both survivors and rescue teams (shelter locations, details of the disaster, regional map information, etc.) is an important component of emergency communications. Since the regular communication channels typically become non-operational in large-scale disasters, a temporary communication infrastructure is needed. Relay networks (e.g., those currently being standardized under IEEE 802.16j) are suitable for such situations in which relay stations may be conveniently positioned in the disaster area in order to expand the coverage of base stations and improve communication reliability. In this article we review the multicast and broadcast services (MBS) mechanism in the current IEEE 802.16j baseline document, which achieves macrodiversity through simultaneous transmissions of the base station and relay stations to the mobile stations. We discuss how it can be used for emergency communications, and propose two different techniques for improving the reliability of MBS in relay networks. Improvements in packet error rate performance are demonstrated through some computer simulations.