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1、NotegDue to the time constraints, only a subset of the slides will be discussed during the INFOCOM 2006 tutorial presentation本资料由-大学生创业|创业|创业网http:/ 在线代理|网页代理|代理网页|http:/ 减肥药排行榜|淘宝最好的减肥药|什么减肥药效果最好|减肥瘦身药|http:/1NotesgNames in brackets, as in Xyz00, refer to a document in the list of referencesgThe ha
2、ndout may not be as readable as the original slides, since the slides contain colored text and figures iNote that different colors in the colored slides may look identical in the black-and-white handout本资料由-大学生创业|创业|创业网http:/ 在线代理|网页代理|代理网页|http:/ 减肥药排行榜|淘宝最好的减肥药|什么减肥药效果最好|减肥瘦身药|http:/2Statutory War
3、ningsgOnly most important features of various schemes are typically discussed, i.e, features I consider as being important iOthers may disagreegMost schemes include many more details, and optimizations iNot possible to cover all details in this tutorialgBe aware that some protocol specs have changed
4、 several times, and the slides may not reflect the most current specificationsgJargon used to discuss a scheme may occasionally differ from that used by the proposers3CoveragegNot intended to be exhaustivegMany interesting papers not covered in the tutorial due to lack of time4Tutorial OutlinegIntro
5、ductiongUnicast routinggMedium Access Control gPerformance of UDP and TCPgSelected security issuesgImplementation IssuesgStandards activitiesgOpen problems5Mobile Ad Hoc Networks (MANET)Introduction and Generalities6Mobile Ad Hoc NetworksgFormed by wireless hosts which may be mobilegWithout (necessa
6、rily) using a pre-existing infrastructuregRoutes between nodes may potentially contain multiple hops7Mobile Ad Hoc NetworksgMay need to traverse multiple links to reach a destinationAB8Mobile Ad Hoc Networks (MANET)gMobility causes route changesAB9Why Ad Hoc Networks ?gEase of deploymentgSpeed of de
7、ploymentgDecreased dependence on infrastructure10Many ApplicationsgPersonal area networking icell phone, laptop, ear phone, wrist watchgMilitary environments isoldiers, tanks, planesgCivilian environments iMesh networks itaxi cab network imeeting rooms isports stadiums iboats, small aircraftgEmergen
8、cy operations isearch-and-rescue ipolicing and fire fighting11Many VariationsgFully Symmetric Environment iall nodes have identical capabilities and responsibilitiesgAsymmetric Capabilities itransmission ranges and radios may differ ibattery life at different nodes may differ iprocessing capacity ma
9、y be different at different nodes ispeed of movementgAsymmetric Responsibilities ionly some nodes may route packets isome nodes may act as leaders of nearby nodes (e.g., cluster head)12Many VariationsgTraffic characteristics may differ in different ad hoc networks ibit rate itimeliness constraints i
10、reliability requirements iunicast / multicast / geocast ihost-based addressing / content-based addressing / capability-based addressinggMay co-exist (and co-operate) with an infrastructure -based network13Many VariationsgMobility patterns may be different ipeople sitting at an airport lounge iNew Yo
11、rk taxi cabs ikids playing imilitary movements ipersonal area networkgMobility characteristics ispeed ipredictabilitydirection of movementpattern of movement iuniformity (or lack thereof) of mobility characteristics among different nodes14ChallengesgLimited wireless transmission rangegBroadcast natu
12、re of the wireless medium iHidden terminal problem (see next slide)gPacket losses due to transmission errorsgMobility-induced route changesgMobility-induced packet lossesgBattery constraintsgPotentially frequent network partitionsgEase of snooping on wireless transmissions (security hazard)15Hidden
13、Terminal ProblemBCANodes A and C cannot hear each otherTransmissions by nodes A and C can collide at node BNodes A and C are hidden from each other16Research on Mobile Ad Hoc NetworksVariations in capabilities & responsibilitiesX Variations in traffic characteristics, mobility models, etc.X Performa
14、nce criteria (e.g., optimize throughput, reduce energy consumption)+Increased research funding= Significant research activity17The Holy GrailgA one-size-fits-all solution iPerhaps using an adaptive/hybrid approach that can adapt to situation at handgDifficult problemgMany solutions proposed trying t
15、o address a sub-space of the problem domain18AssumptiongUnless stated otherwise, fully symmetric environment is assumed implicitly iall nodes have identical capabilities and responsibilities19Unicast Routing in Mobile Ad Hoc Networks20Why is Routing in MANET different ?gHost mobility ilink failure/r
16、epair due to mobility may have different characteristics than those due to other causesgRate of link failure/repair may be high when nodes move fastgNew performance criteria may be used iroute stability despite mobility ienergy consumption21Unicast Routing ProtocolsgMany protocols have been proposedgSome have been invented specifically for MANETgOthers are adapted
