دانلود رایگان مقاله لاتین توزیع محتوای هاپ با برنامه نویسی شبکه از سایت الزویر
عنوان فارسی مقاله:
توزیع محتوای هاپ توسط هاپ با برنامه نویسی شبکه در شبکه بی سیم چند جهشی
عنوان انگلیسی مقاله:
Hop-by-hop Content Distribution with Network Coding in Multihop Wireless Networks
سال انتشار : 2017
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مقدمه انگلیسی مقاله:
1. Introduction
The predominant use of today's Internet is content access anddistribution. Multimedia content traffic is growing at an exponentialrate. This trend is expected to continue in the foreseeablefuture. For example, it is forecasted by Cisco [1] that globalmobile data traffic will increase nearly tenfold between 2014 and2019. Recently, there is renewed research interest in supportingmulticast distribution to deliver various services such as live eventvideo streaming, social content pushing, file sharing, softwareupgrades, mobile TV, as well as other applications for whichmultiple users concurrently consume the same content [2]. Thedemand for these applications is becoming increasingly common,and multicast is much more efficient in delivering them thanunicast by sharing network resources. The Third GenerationPartnership Project (3GPP) recently defined the Evolved MultimediaBroadcast/Multicast Service (eMBMS) standard [3] to supportstreaming and downloading applications. Several operatorshave started field trials for eMBMS services.These multicast applications have strict quality of service (QoS)requirements. Many of them require 100% reliability with highthroughput. Any packet loss may cause severe quality degradation,and users always desire to get content as quickly as possible. It ischallenging to achieve reliable and high-throughput multicast,especially in multihop wireless mesh networks (WMNs) due tointerference, channel fading, and limited bandwidth. Furthermore,a unique issue in multicast is bandwidth heterogeneity amongstmulticast receivers. The receivers with poor network connectivityor a low-throughput path from the source may greatly degrade theperformance of receivers with good network connectivity as thereliability requirements of the worst receiver have to be met.Traditional reliable multicast protocols, including eMBMS, areclient–server based, in which intermediate routers or forwardingnodes simply duplicate and forward packets. These protocolsemploy end-to-end forward error correction (FEC), automatic repeat request (ARQ) or hybrid FEC-ARQ techniques [4–7] at theapplication layer of the clients and servers to achieve multicastreliability. However, their performance is limited by the multicastreceivers with the worst path from the source.Network coding (NC) is an innovative technique to improvereliability and throughput in WMNs. The basic idea of NC is toallow intermediate forwarding nodes (FNs) to encode data packets,instead of simply replicating and forwarding packets, and thustake advantage of the wireless broadcast medium to reduce thenumber of required transmissions for delivery of the data [8,9].Especially, intra-flow random linear network coding [10,11] hasattracted interest due to its low control overhead and high effi-ciency along with implementation simplicity, in which a FN randomlygenerates linear combinations of received packets belongingto a data flow over some fields, and forwards the codedpackets. Random mixing at each FN ensures that if a group of FNshear the same packet transmission, with high probability, thecoded packets generated and forwarded by the different FNs willbe linearly independent, removing duplicate packet transmissionsover shared wireless medium. A node can not only receive thepackets from its direct parent node but also overhear the codedpackets of the same data flow transmitted by other neighbors.Intra-flow random NC thus makes opportunistic forwarding andoverhearing more effective in WMNs so as to achieve significantperformance gains compared to non-coding schemes.However, the use of NC introduces new challenges in designinga practical multicast protocol. First, a FN does not need to encodeand then forward a coded packet whenever it receives a packetfrom its upstream node because its downstream node may overhearpackets from other neighbors. Consider a simple example inwhich a source S multicasts two packets, P1 and P2, to two destinationreceivers, D1 and D2 through a FN, F, as shown in Fig. 1. Stransmits two coded packets, P P 1 2 + and P P 1 2 + 2 in sequence,which can be represented by the corresponding coding vectors (1,1) and (1, 2). Assume that F receives both packets, and D1 and D2overhear coded packets (1, 1) and (1, 2), respectively. In fact, F onlyneeds to generate one coded packet from the received two packets,e.g. 3P P 1 2 + 4 , and forward it. D1 and D2 can decode and obtainthe original packets P1 and P2 after they receive coded packet3P P 1 2 + 4 from F. However, F may not know that D1 and D2 haveoverheard a packet from S as it has limited knowledge of the receptionstatus of D1 and D2 with regard to the two packets sent byS. It is nontrivial for F to decide the number of coded packets itshould send and the time when to stop sending. Therefore, onechallenge in the NC protocol design is to address how many codedpackets each FN should send in order to guarantee all the multicastdestination receivers obtain enough packets to decode theoriginal data. In addition, how should the bandwidth heterogeneityof the paths from the source to the different destinationreceivers be handled by the multicast protocol? To deliver thebenefits offered by intra-flow NC, a practical protocol needs toaddress the above challenges.Although various NC schemes have been studied under differentnetwork settings, practical protocol design for reliable multicastwith NC in WMNs has received relatively little attention.MORE [11] and Pacifier [12] are the two state-of-the-art intra-flowNC-based multicast protocols with different selections of forwardingnode topologies. Both of them employ a transmissioncredit (TX_Credit) approach, in which the source computes andassigns a TX_Credit to each FN based on the periodical packet lossrate measurements of the links on the network. The sourcetransmits the coded packets from a data chunk, and the TX_Creditvalues are carried in the packet header that indicates the numberof coded packets a FN should transmit upon receiving the packetfrom its upstream node. An intermediate FN simply determineswhether and how many coded packets transmit to its downstreamnodes according to the TX_Credit assigned to it in the receivedpacket. The successful data delivery is verified through end-to-endacknowledgements (ACKs). The source continues sending codedpackets until it receives the ACKs from all its multicast destinationreceivers. However, with this approach, the FNs may transmit thepackets much more than necessary, significantly wasting wirelessresources, because it is very difficult to obtain the accurate estimationof the TX_Credit for each FN in dynamic wireless environments,and the end-to-end ACKs may be delayed or lost.In this paper, we take a different approach, and propose a novelintra-flow NC-based hop-by-hop reliable multicast protocol,termed HopCaster, to achieve high-throughput over WMNs andsolve the bandwidth heterogeneity issue of multicast receivers. Incontrast to the existing NC-based multicast protocols, HopCastercompletely eliminates the need for estimating the TX_Credit, aswell as simplifying multicast management and congestion control.Moreover, a cross-layer rate adaptation mechanism is proposed,which maximizes the multicast throughput by dynamically adjustingthe wireless transmission rate to the changes in the receiverpopulation and wireless channels during multicast of acoded data chunk. The evaluation results show that HopCasterachieves significant throughput gains compared to the state-ofthe-artNC-based multicast protocols.The remainder of this paper is organized as follows. Relatedwork is reviewed in Section 2. In Section 3, we present the HopCasterprotocol design. Section 4 describes the cross-layer rateadaptation mechanism. In Section 5 we show the evaluation resultsand performance comparison of HopCaster with the existingNC-based multicast protocol. The paper is concluded in Section 6.
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کلمات کلیدی:
[PDF]A Wireless Medium Access Control Using Network Coding for Multi ...https://www.eecs.harvard.edu/~htk/.../2008-milcom-cheng-kung-lin-su-vlah.pdfby CM Cheng - Cited by 18 - Related articlesRainbow: A Wireless Medium Access Control Using Network Coding for Multi-hop Content ... ticularly important to data broadcast in wireless distributed computing where ... tribution protocol for multi-hop wireless ad-hoc networks. The protocol ...[PDF]Network Coding for Multi- Hop Wireless Networks - IRMA Internationalwww.irma-international.org/viewtitle/36549/Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. ... Network Coding for Multi-Hop Wireless Networks.[PDF]Application of network coding in wireless networks - Halhttps://hal.archives-ouvertes.fr/tel-01022166/documentRelated articlesJul 10, 2014 - 2.5.2 Distributed Coding-Aware Routing (DCAR) . . . . . . . . . . 23 ... 2.7.1.1 Multi-hop traffic flows in wireless networks . . . . . . 33. 2.7.1.2 ...Hop-by-hop Content Distribution with Network Coding in Multihop ...https://www.researchgate.net/.../308004170_Hop-by-hop_Content_Distribution_with_N...Download academic paper: Hop-by-hop Content Distribution with Network Coding in Multihop Wireless Networks on ResearchGate.Multiantenna Analog Network Coding for Multihop Wireless Networkshttps://www.hindawi.com/journals/ijdmb/2010/368562/by R Annavajjala - 2010 - Cited by 12 - Related articlesOct 26, 2009 - Multiantenna Analog Network Coding for Multihop Wireless Networks ... which permits unrestricted use, distribution, and reproduction in any ...[PDF]Network Coding for Efficient Wireless Unicast - MITwww.rle.mit.edu/ncrc/wp-content/uploads/.../2006_network_coding_efficient.pdfby DS Lun - Cited by 124 - Related articlesunicast connections over wireless packet networks. We show how network coding, combined with distributed flow optimiza- tion, gives a practicable ..... ments for unicast in multi-hop wireless networks, and we have suggested practicable ...Network Coding for Severe Packet Reordering in Multihop Wireless ...dsn.sagepub.com/content/11/8/379108.fullNetwork coding is known to be effective in overcoming packet losses and packet reordering in multihop wireless networks. Despite the benefits, network coding ...
