Mobile InternetWireless Network Architectures and ApplicationsSridhar IyerK R School of Information TechnologyIIT Bombaysri@it.iitb.ac.inhttp://www.it.iitb.ac.in/sriSridhar Iyer IIT Bombay 2!"tlineIntrod"ction and !#er#iew $ireless %&'s: I((( )*+.,, Mobile I- ro"tingT.- o#er wireless/SM air interface/-RS networ0 architect"re$ireless application protocolMobile agentsMobile ad hoc networ0sSridhar Iyer IIT Bombay 3References1. Schiller2 3Mobile .omm"nications42 &ddison $esley2 +***)*+.,, $ireless %&'2 I((( standards2 www.ieee.orgMobile I-2 R5. +**+2 R5. 6672 www.ietf.orgT.- o#er wireless2 R5. 6,8*2 R5. 6,882 R5. 6779&. Mehrotra2 3/SM System (ngineering42 &rtech :o"se2 ,99;Bettstetter2 &d hoc 'etwor0sA "sef"l when infrastr"ct"re not a#ailable2 impractical2 or eDpensi#eA military applications2 resc"e2 home networ0ingSome mobile de#ices Clamshell handhelds Tablets Netenabled mobile phonesPalm-sizedLaptop computersSridhar Iyer IIT Bombay 6%imitations of the mobile en#ironment %imitations of the $ireless 'etwor0 limited comm"nication bandwidth freE"ent disconnections heterogeneity of fragmented networ0s %imitations Imposed by Mobility ro"te brea0ages lac0 of mobility awareness by system/applications %imitations of the Mobile Fe#ice short battery lifetime limited capacitiesSridhar Iyer IIT Bombay 7$ireless #/s $ired networ0sReg"lations of freE"enciesA %imited a#ailability2 coordination is reE"iredA "sef"l freE"encies are almost all occ"piedBandwidth and delaysA %ow transmission ratesG few Kbits/s to some Mbit/s.A :igher delaysG se#eral h"ndred millisecondsA :igher loss rates G s"sceptible to interference2 e.g.2 engines2 lightning&lways shared medi"mA %ower sec"rity2 simpler acti#e attac0ingA radio interface accessible for e#eryoneA 5a0e base stations can attract calls from mobile phonesA sec"re access mechanisms importantSridhar Iyer IIT Bombay 8.ell"lar systems: Basic ideaSingle hop wireless connecti#ityASpace di#ided into cellsA& base station is responsible to comm"nicate with hosts in its cellAMobile hosts can change cells while comm"nicatingA:andCoff occ"rs when a mobile host starts comm"nicating #ia a new base station5actors for determining cell siHeA'o. of "sers to be s"pportedAM"ltipleDing and transmission technologiesSridhar Iyer IIT Bombay 9.ell"lar concept%imited n"mber of freE"encies IJ limited channels:igh power antenna IJ limited n"mber of "sersSmaller cells IJ freE"ency re"se possible IJ more "sersBase stations =BS>: implement space di#ision m"ltipleDA .l"ster: gro"p of nearby BSs that together "se all a#ailable channelsMobile stations comm"nicate only #ia the base stationA 5FM&2 TFM&2 .FM& may be "sed within a cell&s demand increases =more channels are needed>A '"mber of base stations is increasedA Transmitter power is decreased correspondingly to a#oid interferenceSridhar Iyer IIT Bombay 10.ell"lar system architect"re(ach cell is ser#ed by a base station =BS>(ach BSS is connected to a mobile switching center =MS.> thro"gh fiDed lin0s(ach MS. is connected to other MS.s and -ST'MSC MSCHLRVLRHLRVLRTo otherMSC!ST" !ST"Sridhar Iyer IIT Bombay 11!"tgoing call set"p!"tgoing call set"p:A@ser 0eys in the n"mber and presses sendAMobile transmits access reE"est on "plin0 signaling channelAIf networ0 can process the call2 BS sends a channel allocation messageA'etwor0 proceeds to set"p the connection'etwor0 acti#ity:AMS. determines c"rrent location of target mobile "sing :%R2 initiates a paging messageABSs forward the paging message on downlin0 channel in co#erage areaAIf mobile is on =monitoring the signaling channel>2 it responds to BSABS sends a channel allocation message and informs MS.'etwor0 acti#ity:A'etwor0 completes the two hal#es of the connectionSridhar Iyer IIT Bombay 13:andC!ffsBS initiated:A :andoff occ"rs if signal le#el of mobile falls below thresholdA Increases load on BSG Monitor signal le#el of each mobileG Fetermine target BS for handoffMobile assisted:A (ach BS periodically transmits beaconA Mobile2 on hearing stronger beacon from a new BS2 initiates the handoffIntersystem:A Mobile mo#es across areas controlled by different MS.KsA :andled similar to mobile assisted case with additional :%R/A 5reE"ency shift 0eyingB 5FM& for spectr"m sharingA 'MT =("rope>2 &M-S =@S>SecondCgeneration: Figital cell"lar systems =9**2 ,)** M:H>A TFM&/.FM& for spectr"m sharingB .irc"it switchingA /SM =("rope>2 ISC,6M =@S>2 -F. =1apan>A N9.M0bps data rates+.8/: -ac0et switching eDtensionsA Figital: /SM to /-RSB &nalog: &M-S to .F-FA N,,80bps data rates6/: 5"llCfledged data ser#icesA :igh speed2 data and Internet ser#icesA IMTC+***2 @MTSA N+Mbps data ratesSridhar Iyer IIT Bombay 21/SM to /-RSRadio reso"rces are allocated for only one or a few pac0ets at a time2 so /-RS enablesAmany "sers to share radio reso"rces2 and allow efficient transport of pac0etsAconnecti#ity to eDternal pac0et data networ0sA#ol"meCbased charging:igh data rates ="p to ,;, 0bps in ideal case>/-RS carries SMS in data channels rather than signaling channels as in /SMSridhar Iyer IIT Bombay 22@MTS: @ni#ersal Mobile Telecomm. Standard/lobal seamless operation in m"ltiCcell en#ironment =S&T2 macro2 micro2 pico>/lobal roaming: m"ltiCmode2 m"ltiCband2 lowCcost terminal2 portable ser#ices O PoS:igh data rates at different mobile speeds: ,770bps at #ehic"lar speed =)*0m/h>2 6)7 0bps at pedestrian speed2 and +Mbps indoor =office/home>M"ltimedia interface to the internetBased on core /SM2 conforms to IMTC+***$C.FM& as the airCinterfaceSridhar Iyer IIT Bombay 23(#ol"tion to 6/ TechnologiesIS-95BCDMA2G Gcd!a2"""GSM#DD$DDW-CDMAG%&SIS-'($DMA)WC-'(*DG* + '(,S outdoor'( ,SindoorSridhar Iyer IIT Bombay 246)7 Kbps6)7 Kbps8M Kbps8M Kbps87 Mbps87 Mbps;+ Mbps;+ Mbps8C,, Mbps8C,, Mbps,C+ Mbps,C+ Mbps )*+.,,$ireless Technology %andscapeBl"etooth)*+.,,b)*+.,,Qa2bRT"rbo .,,aIndoor,* A 6*mISC982 /SM2 .FM&$.FM&2 .FM&+***!"tdoor8* A +**mMid rangeo"tdoor+**m A 7Km%ong rangeo"tdoor8Km A +*Km%ong distance com.+*m A 8*Km-wa.e p-to-p links .,, pCtoCp lin0+/6/Sridhar Iyer IIT Bombay 2#6/ 'etwor0 &rchitect"reMobi%e AccessRo*terMobi%e AccessRo*ter6ire%essAccess )et+ork&P7ase Stations&P7ase StationsGate+a- Gate+a-Te%ep/one )et+orkCore )et+orkUser Pro(i%es 8A*t/entication9.#R:5G Air&nter(ace6ired Access402.22&P &ntranet&P &ntranetProgra''ab%eSo(ts+itc/Progra''ab%eSo(ts+itc/App%icationSer$erApp%icationSer$er402.22Access PointAccess PointAccess PointAccess Point&nternetSridhar Iyer IIT Bombay 26$ireless %&'sInfrared =IrF&> or radio lin0s =$a#elan>&d#antagesA#ery fleDible within the reception area A&dChoc networ0s possibleA=almost> no wiring diffic"lties Fisad#antagesAlow bandwidth compared to wired networ0sAmany proprietary sol"tionsInfrastr"ct"re #/s adChoc networ0s =)*+.,,>Sridhar Iyer IIT Bombay 27Infrastr"ct"re #s. &dhoc 'etwor0sinfrastr"ct"re networ0adChoc networ0&-&-&-wired networ0&-: &ccess -ointSo"rce: SchillerSridhar Iyer IIT Bombay 28Fifference Between $ired and $irelessIf both & and . sense the channel to be idle at the same time2 they send at the same time..ollision can be detected at sender in (thernet.:alfCd"pleD radios in wireless cannot detect collision at sender.A B CABC*thernet /ANWireless /ANSridhar Iyer IIT Bombay 29A& and . cannot hear each other.A& sends to B2 . cannot recei#e &. A. wants to send to B2 . senses a 3free4 medi"m =.S fails>A.ollision occ"rs at B.A& cannot recei#e the collision =.F fails>.A& is 3hidden4 for ..:idden Terminal -roblemB A CSridhar Iyer IIT Bombay 30I((( )*+.,,&c0nowledgements for reliabilitySignaling pac0ets for collision a#oidanceARTS =reE"est to send> A.TS =clear to send> Signaling =RTS/.TS> pac0ets containAsender addressArecei#er addressAd"ration =pac0et siHe S &.K>-owerCsa#e modeSridhar Iyer IIT Bombay 31Spectr"m $ar: Stat"s todayEnterprise 802.11Netor!Public 802.11 "ireless CarrierSo"rce: -ra#in BhagwatSridhar Iyer IIT Bombay 32Spectr"m $ar: (#ol"tionEnterprise 802.11Netor!Public 802.11 "ireless Carrier#ar!et consolidationEntr$ o% "ireless CarriersEntr$ o% ne pla$ers&ootprint 'rothSo"rce: -ra#in BhagwatSridhar Iyer IIT Bombay 33Spectr"m $ar: Steady StateEnterprise 802.11Netor!Public 802.11 "ireless CarrierVirtual CarrierEmer'ence o% (irtual carriers)oamin' a'reementsSo"rce: -ra#in BhagwatSridhar Iyer IIT Bombay 34Ro"ting and Mobility5inding a path from a so"rce to a destinationIss"esA5reE"ent ro"te changesARo"te changes may be related to host mo#ementA%ow bandwidth lin0s/oal of ro"ting protocolsAdecrease ro"tingCrelated o#erheadAfind short ro"tesAfind 3stable4 ro"tes =despite mobility>Sridhar Iyer IIT Bombay 3#Mobile I-: Basic Idea&outer'&outer

&outer2SMN,o!e a0entSo"rce: Session %ayer =$S->&pplication %ayer =$&(>Transport %ayer =$F->T.-/I-2@F-/I-2mediaSS%/T%S:TM%2 1a#a:TT-Internet WA%$&( comprises $M% =$ireless Mar0"p %ang"age>2 $M% Script2 $T&I etc.So"rce: SchillerTransaction %ayer =$T->additional ser#ices and applications$.M-&CS&-SCS&-TRCS&-S(.CS&-TCS&-Sridhar Iyer IIT Bombay 49$&- Stac0 !#er#iew$F-A f"nctionality similar to @F- in I- networ0s$T%SA f"nctionality similar to SS%/T%S =optimiHed for wireless>$T-A .lass *: analogo"s to @F-A .lass ,: analogo"s to T.- =witho"t connection set"p o#erheads>A .lass +: analogo"s to R-. =optimiHed for wireless>A feat"res of 3"ser ac0nowledgement42 3hold on4$S-A $S-/B: analogo"s to http ,., =add feat"res of s"spend/res"me>Amethod: analogo"s to R-./RMIA feat"res of asynchrono"s in#ocations2 p"sh =confirmed/"nconfirmed>Sridhar Iyer IIT Bombay #0The Mobile &gent ModelMobile agent recei#es client reE"est and Mobile agent mo#es into fiDed networ0Mobile agent acts as a client to the ser#erMobile agent performs transformations and filteringMobile agent ret"rns bac0 to mobile platform2 when the client is connectedSridhar Iyer IIT Bombay #1Mobile &gents: (DampleSridhar Iyer IIT Bombay #2!"tlineIntrod"ction and !#er#iew Wireless /ANs5 I*** 6"27''Mobile I- ro"tingT.- o#er wireless/SM air interface/-RS networ0 architect"re$ireless application protocolMobile agentsMobile ad hoc networ0sSridhar Iyer IIT Bombay #3:ow $ireless %&'s are differentFestination address does not eE"al destination locationThe media impact the designAwireless %&'s intended to co#er reasonable geographic distances m"st be b"ilt from basic co#erage bloc0sImpact of handling mobile =and portable> stationsA-ropagation effects AMobility managementApower managementSridhar Iyer IIT Bombay #4$ireless Media-hysical layers in wireless networ0sA @se a medi"m that has neither absol"te nor readily obser#able bo"ndaries o"tside which stations are "nable to recei#e framesA &re "nprotected from o"tside signalsA .omm"nicate o#er a medi"m significantly less reliable than wired -:UsA :a#e dynamic topologiesA %ac0 f"ll connecti#ity and therefore the ass"mption normally made that e#ery station =ST&> can hear e#ery other ST& in in#alid =I.e.2 ST&s may be 3hidden4 from each other>A :a#e time #arying and asymmetric propagation propertiesSridhar Iyer IIT Bombay ##)*+.,,: Moti#ation.an we apply media access methods from fiDed networ0s(Dample .SM&/.FA Carrier Sense M"ltiple Access with Collision DetectionA send as soon as the medi"m is free2 listen into the medi"m if a collision occ"rs =original method in I((( )*+.6>Medi"m access problems in wireless networ0sA signal strength decreases proportional to the sE"are of the distanceA sender wo"ld apply .S and .F2 b"t the collisions happen at the recei#erA sender may not 3hear4 the collision2 i.e.2 .F does not wor0A .S might not wor02 e.g. if a terminal is 3hidden4:idden and eDposed terminalsSridhar Iyer IIT Bombay #6Sol"tion for :idden/(Dposed Terminals& first sends a Request-to-Send (RTS) to B!n recei#ing RTS2 B responds Clear-to-Send (CTS):idden node . o#erhears .TS and 0eeps E"ietA Transfer d"ration is incl"ded in both RTS and .TS(Dposed node o#erhears a RTS b"t not the .TSA FKs transmission cannot interfere at BA B C&$SC$SC$SDA$AD&$SSridhar Iyer IIT Bombay #7I((( )*+.,,$ireless %&' standard defined in the "nlicensed spectr"m =+.7 /:H and 8 /:H @C'II bands>Standards co#ers the M&. s"blayer and -:U layersThree different physical layers in the +.7 /:H bandA 5:SS2 FSSS and IR!5FM based -:U layer in the 8 /:H band Sridhar Iyer IIT Bombay #8.omponents of I((( )*+.,, architect"reThe basic ser#ice set =BSS> is the basic b"ilding bloc0 of an I((( )*+.,, %&'The o#als can be tho"ght of as the co#erage area within which member stations can directly comm"nicate The Independent BSS =IBSS> is the simplest %&'. It may consist of as few as two stationsad-hoc networkBSS2BSS1Sridhar Iyer IIT Bombay #9)*+.,, C adChoc networ0 =F.5>Firect comm"nication within a limited rangeA Station =ST&>:terminal with access mechanisms to the wireless medi"mA Basic Ser#ice Set =BSS>:gro"p of stations "sing the same radio freE"ency802.11 L!BSS+802.11 L!BSS,ST&,ST&7ST&8ST&+ST&6So"rce: SchillerSridhar Iyer IIT Bombay 60Fistrib"tion System-ortal802.x L!&ccess -oint802.11 L!BSS+802.11 L!BSS,&ccess -oint)*+.,, C infrastr"ct"re networ0 =-.5>Station =ST&>A terminal with access mechanisms to the wireless medi"m and radio contact to the access pointBasic Ser#ice Set =BSS>A gro"p of stations "sing the same radio freE"ency&ccess -ointA station integrated into the wireless %&' and the distrib"tion system-ortalA bridge to other =wired> networ0sFistrib"tion SystemA interconnection networ0 to form one logical networ0 =((S: (Dtended Ser#ice Set> based on se#eral BSSST&,ST&+ST&6(SSSo"rce: SchillerSridhar Iyer IIT Bombay 61Fistrib"tion System =FS> conceptsThe Fistrib"tion system interconnects m"ltiple BSSs)*+.,, standard logically separates the wireless medi"m from the distrib"tion system A it does not precl"de2 nor demand2 that the m"ltiple media be same or different&n &ccess -oint =&-> is a ST& that pro#ides access to the FS by pro#iding FS ser#ices in addition to acting as a ST&. Fata mo#es between BSS and the FS #ia an &-The FS and BSSs allow )*+.,, to create a wireless networ0 of arbitrary siHe and compleDity called the(Dtended Ser#ice Set networ0 =(SS>Sridhar Iyer IIT Bombay 62)*+.,,C in the T.-/I- stac0mobile terminalaccess pointser#erfiDed terminalapplicationT.-)*+.,, -:U)*+.,, M&.I-)*+.6 M&.)*+.6 -:UapplicationT.-)*+.6 -:U)*+.6 M&.I-)*+.,, M&.)*+.,, -:U%%.infrastr"ct"re networ0%%. %%.Sridhar Iyer IIT Bombay 63)*+.,, C %ayers and f"nctions-%.- -hysical %ayer .on#ergence -rotocolA clear channel assessment signal =carrier sense>-MF -hysical Medi"m FependentA mod"lation2 coding-:U ManagementA channel selection2 MIBStation ManagementA coordination of all management f"nctions-MF-%.-M&.%%.M&. Management-:U ManagementM&.A access mechanisms2 fragmentation2 encryption M&. ManagementA synchroniHation2 roaming2 MIB2 power management-:UF%.Station Management;.).,Sridhar Iyer IIT Bombay 64)*+.,, C -hysical layer6 #ersions: + radio =typically +.7 /:H>2 , IRA data rates ,2 +2 or ,, Mbit/s5:SS =5reE"ency :opping Spread Spectr"m>A spreading2 despreading2 signal strength2 typically , Mbit/sA min. +.8 freE"ency hops/s =@S&>2 twoCle#el /5SK mod"lationFSSS =Firect SeE"ence Spread Spectr"m>A FB-SK mod"lation for , Mbit/s =Fifferential Binary -hase Shift Keying>2 FP-SK for + Mbit/s =Fifferential P"adrat"re -SK>A preamble and header of a frame is always transmitted with , Mbit/sA chipping seE"ence: S,2 C,2 S,2 S,2 C,2 S,2 S,2 S,2 C,2 C,2 C, =Bar0er code>A maD. radiated power , $ =@S&>2 ,** m$ =(@>2 min. ,m$InfraredA )8*C98* nm2 diff"se light2 typ. ,* m rangeA carrier detection2 energy detection2 synchoniHationSridhar Iyer IIT Bombay 6#SpreadCspectr"m comm"nicationsSo"rce: IntersilSridhar Iyer IIT Bombay 66FSSS Bar0er .ode mod"lationSo"rce: IntersilSridhar Iyer IIT Bombay 67FSSS propertiesSo"rce: IntersilSridhar Iyer IIT Bombay 68)*+.,, C M&. layerTraffic ser#icesA &synchrono"s Fata Ser#ice =mandatory> A F.5A TimeCBo"nded Ser#ice =optional> C -.5&ccess methodsA F.5 .SM&/.& =mandatory>G collision a#oidance #ia randomiHed bac0Coff mechanismG &.K pac0et for ac0nowledgements =not for broadcasts>A F.5 w/ RTS/.TS =optional>G a#oids hidden terminal problemA -.5 =optional>G access point polls terminals according to a listSridhar Iyer IIT Bombay 69)*+.,, C .arrier SensingIn I*** 6"27''8 carrier sensin0 is per3or!ed A at the air interface =p"#s$%al %arr$er sens$n&>2 andA at the M&. layer ='$rtual %arr$er sens$n&>%h9sical carrier sensin0 A detects presence of other "sers by analyHing all detected pac0etsA Fetects acti#ity in the channel #ia relati#e signal strength from other so"rces:irtual carrier sensin0 is done by sending M-F@ d"ration information in the header of RTS/.TS and data frames.hannel is b"sy if either mechanisms indicate it to beA F"ration field indicates the amo"nt of time =in microseconds> reE"ired to complete frame transmissionA Stations in the BSS "se the information in the d"ration field to ad?"st their networ0 allocation #ector ='&Sridhar Iyer IIT Bombay 70)*+.,, C Reliability@se of ac0nowledgementsA $hen B recei#es F&T& from &2 B sends an &.KA If & fails to recei#e an &.K2 & retransmits the F&T&A Both . and F remain E"iet "ntil &.K =to pre#ent collision of &.K>A (Dpected d"ration of transmissionS&.K is incl"ded in RTS/.TS pac0etsA B C&$SC$SC$SDA$AD&$SAC;Sridhar Iyer IIT Bombay 71)*+.,, C -rioritiesdefined thro"gh different inter frame spaces A mandatory idle time inter#als between the transmission of frames SI5S =Short Inter 5rame Spacing>A highest priority2 for &.K2 .TS2 polling responseA SI5STimeand SlotTime are fiDed per -:U layer A =,* s and +* s respecti#ely in FSSS>-I5S =-.5 I5S>A medi"m priority2 for timeCbo"nded ser#ice "sing -.5A -I5STime I SI5STime S SlotTimeFI5S =F.5 I5S>Alowest priority2 for asynchrono"s data ser#iceA F.5CI5S =FI5S>: FI5STime I SI5STime S +DSlotTimeSridhar Iyer IIT Bombay 72tmedi"m b"syFI5S FI5SneDt framecontention window=randomiHed bac0Coffmechanism>)*+.,, C .SM&/.&A station ready to send starts sensing the medi"m =.arrier Sense based on ..&2 .lear .hannel &ssessment>A if the medi"m is free for the d"ration of an InterC5rame Space =I5S>2 the station can start sending =I5S depends on ser#ice type>A if the medi"m is b"sy2 the station has to wait for a free I5S2 then the station m"st additionally wait a random bac0Coff time =collision a#oidance2 m"ltiple of slotCtime> A if another station occ"pies the medi"m d"ring the bac0Coff time of the station2 the bac0Coff timer stops =fairness>slot timedirect access if medi"m is free FI5SSridhar Iyer IIT Bombay 73)*+.,, A.SM&/.& eDampletb"syboestation,station+station6station7station8pac0et arri#al at M&.FI5Sboeboeboeb"syelapsed bac0off timeborresid"al bac0off timeb"symedi"m not idle =frame2 ac0 etc.> borborFI5SboeboeboeborFI5Sb"syb"syFI5Sboeb"syboeboeborborSridhar Iyer IIT Bombay 74)*+.,, C .ollision oidance.ollision a#oidance: !nce channel becomes idle2 the node waits for a randomly chosen d"ration before attempting to transmitF.5 A $hen transmitting a pac0et2 choose a bac0off inter#alin the range V*2cwWB cw is contention windowA .o"nt down the bac0off inter#al when medi"m is idleA .o"ntCdown is s"spended if medi"m becomes b"syA $hen bac0off inter#al reaches *2 transmit RTSTime spent co"nting down bac0off inter#als is part of M&. o#erheadSridhar Iyer IIT Bombay 7#F.5 (DampledatawaitB, I 8B+ I ,8B, I +8B+ I +*datawaitB' and B2 are in F.5: .ongestion control achie#ed by dynamically choosing cwlar&e cw leads to larger bac0off inter#alss(all cw leads to larger n"mber of collisionsBinary (Dponential Bac0off in F.5:A$hen a node fails to recei#e .TS in response to its RTS2 it increases the contention windowG cw is do"bled ="p to a bo"nd .$maD>A@pon s"ccessf"l completion data transfer2 restore cw to .$minSridhar Iyer IIT Bombay 77)*+.,, C .SM&/.& IIstation has to wait for FI5S before sending datarecei#ers ac0nowledge at once =after waiting for SI5S> if the pac0et was recei#ed correctly =.R.>a"tomatic retransmission of data pac0ets in case of transmission errorstSI5SFI5Sdata&.Kwaiting timeotherstationsrecei#ersenderdataFI5ScontentionSridhar Iyer IIT Bombay 78)*+.,, ARTS/.TSstation can send RTS with reser#ation parameter after waiting for FI5S =reser#ation determines amo"nt of time the data pac0et needs the medi"m> ac0nowledgement #ia .TS after SI5S by recei#er =if ready to recei#e>sender can now send data at once2 ac0nowledgement #ia &.Kother stations store medi"m reser#ations distrib"ted #ia RTS and .TS tSI5SFI5Sdata&.Kdefer accessotherstationsrecei#ersenderdataFI5ScontentionRTS.TSSI5SSI5S'&< =RTS>'&< =.TS>Sridhar Iyer IIT Bombay 795ragmentationtSI5SFI5Sdata&.K,otherstationsrecei#ersenderfrag,FI5ScontentionRTS.TSSI5SSI5S'&< =RTS>'&< =.TS>'&< =frag,>'&< =&.K,>SI5S&.K+frag+SI5SSridhar Iyer IIT Bombay 80)*+.,, C -oint .oordination 5"nctionSridhar Iyer IIT Bombay 81)*+.,, C -.5 I-I5SstationsX'&adChoc networ0 * * F& S& BSSIF Cinfrastr"ct"renetwor02 from &-* , F& BSSIF S& Cinfrastr"ct"renetwor02 to &-, * BSSIF S& F& Cinfrastr"ct"renetwor02 within FS, , R& T& F& S&FS: Fistrib"tion System&-: &ccess -ointF&: Festination &ddressS&: So"rce &ddressBSSIF: Basic Ser#ice Set IdentifierR&: Recei#er &ddressT&: Transmitter &ddressSridhar Iyer IIT Bombay 91)*+.,, C M&. managementSynchroniHationA try to find a %&'2 try to stay within a %&'A timer etc.-ower managementA sleepCmode witho"t missing a messageA periodic sleep2 frame b"ffering2 traffic meas"rements&ssociation/ReassociationA integration into a %&'A roaming2 i.e. change networ0s by changing access pointsA scanning2 i.e. acti#e search for a networ0MIB C Management Information BaseA managing2 read2 writeSridhar Iyer IIT Bombay 92)*+.,, C SynchroniHation&ll ST&s within a BSS are synchroniHed to a common cloc0 A -.5 mode: &- is the timing master G periodically transmits Beacon frames containing Timing SynchroniHation f"nction =TS5>G Recei#ing stations accepts the timestamp #al"e in TS5A F.5 mode: TS5 implements a distrib"ted algorithmG (ach station adopts the timing recei#ed from any beacon that hasTS5 #al"e later than its own TS5 timerThis mechanism 0eeps the synchroniHation of the TS5 timers ina BSS to within 7 s pl"s the maDim"m propagation delayof the -:U layerSridhar Iyer IIT Bombay 93SynchroniHation "sing a Beacon =infrastr"ct"re>beacon inter#altmedi"maccesspointb"syBb"sy b"sy b"syB B B#al"e of the timestampBbeacon frameSridhar Iyer IIT Bombay 94SynchroniHation "sing a Beacon =adChoc>tmedi"mstation,b"syB,beacon inter#alb"sy b"sy b"syB,#al"e of the timestampBbeacon framestation+B+B+random delaySridhar Iyer IIT Bombay 9#)*+.,, C -ower managementIdea: switch the transcei#er off if not neededA States of a station: sleep and awa0eTiming SynchroniHation 5"nction =TS5>A stations wa0e "p at the same timeInfrastr"ct"reA Traffic Indication Map =TIM>G list of "nicast recei#ers transmitted by &-A Feli#ery Traffic Indication Map =FTIM>G list of broadcast/m"lticast recei#ers transmitted by &-&dChocA &dChoc Traffic Indication Map =&TIM>G anno"ncement of recei#ers by stations b"ffering framesG more complicated C no central &-G collision of &TIMs possible =scalabilityZ>Sridhar Iyer IIT Bombay 96)*+.,, C (nergy conser#ation-ower Sa#ing in I((( )*+.,, =Infrastr"ct"re Mode>A&n &ccess -oint periodically transmits a beacon indicating which nodes ha#e pac0ets waiting for themA(ach power sa#ing =-S> node wa0es "p periodically to recei#e the beaconAIf a node has a pac0et waiting2 then it sends a -SC-ollG &fter waiting for a bac0off inter#al in V*2.$minWA&ccess -oint sends the data in response to -SCpollSridhar Iyer IIT Bombay 97-ower sa#ing with wa0eC"p patterns =infrastr"ct"re>TIM inter#altmedi"maccesspointb"syFb"sy b"sy b"syT T FTTIMFFTIMFTIM inter#alB BBbroadcast/m"lticaststationawa0ep-S pollpddddata transmissionto/from the stationSridhar Iyer IIT Bombay 98-ower sa#ing with wa0eC"p patterns =adChoc>awa0e&transmit &TIMFtransmit datatstation,B,B,Bbeacon framestation+B+B+random delay&aFd&TIMwindowbeacon inter#alaac0nowledge &TIMdac0nowledge dataSridhar Iyer IIT Bombay 99)*+.,, C Roaming'o or bad connection in -.5 modeZ Then perform:ScanningA scan the en#ironment2 i.e.2 listen into the medi"m for beacon signals or send probes into the medi"m and wait for an answerReassociation ReE"estA station sends a reE"est to one or se#eral &-=s>Reassociation ResponseA s"ccess: &- has answered2 station can now participateA fail"re: contin"e scanning&- accepts Reassociation ReE"estA signal the new station to the distrib"tion systemA the distrib"tion system "pdates its data base =i.e.2 location information>A typically2 the distrib"tion system now informs the old &- so it can release reso"rcesSridhar Iyer IIT Bombay 100:ardware!riginal $a#e%&' card ='.R>A 9,7 M:H Radio 5reE"encyA Transmit power +),.) m$A Transmission Range +8* m =o"tdoors> at +MbpsA S'RT ,* dB =capt"re>$a#e%&' II =%"cent>A +.7 /:H radio freE"ency rangeA Transmit -ower 6*m$A Transmission range 6;M m =o"tdoors> at + Mbps =M*m indoors>A Recei#e Threshold I A),dBm A .arrier Sense Threshold I C,,,dBmSridhar Iyer IIT Bombay 101)*+.,, c"rrent stat"sMACMIBDSSS #, I&%,?W*%//CMAC M0!t)*+.,,b82,, Mbps)*+.,,g+*S Mbps)*+.,,aM292,+2,)2+76M27)287 Mbps@#DM)*+.,,isec"rity)*+.,,fInter &ccess -oint -rotocol)*+.,,ePoS enhancementsSridhar Iyer IIT Bombay 102I((( )*+.,, S"mmaryInfrastr"ct"re =-.5> and adhoc =F.5> modesSignaling pac0ets for collision a#oidanceA Medi"m is reser#ed for the d"ration of the transmissionA Beacons in -.5A RTSC.TS in F.5&c0nowledgements for reliabilityBinary eDponential bac0off for congestion control-ower sa#e mode for energy conser#ationSridhar Iyer IIT Bombay 103!"tlineIntrod"ction and !#er#iew $ireless %&'s: I((( )*+.,,MoA host in the home networ0 of the M'2 typically a ro"terA registers the location of the M'2 t"nnels I- pac0ets to the .!&5oreign &gent =5&>A host in the c"rrent foreign networ0 of the M'2 typically a ro"terA forwards t"nneled pac0ets to the M'2 typically the defa"lt ro"ter for M'.areCof &ddress =.!&>A address of the c"rrent t"nnel endCpoint for the M' =at 5& or M'>A act"al location of the M' from an I- point of #iew.orrespondent 'ode =.'>A host with which M' is 3corresponding4 =T.- connection> Sridhar Iyer IIT Bombay 110Fata transfer to the mobile systemInternetsender#A,AMNho!e network3orei0nnetworkrecei#er'2

,. Sender sends to the I- address of M'2:& intercepts pac0et =proDy &R->+. :& t"nnels pac0et to .!&2 here 5&2 by encaps"lation6. 5& forwards the pac0et to the M'So"rce: SchillerCNSridhar Iyer IIT Bombay 111Fata transfer from the mobile systemInternetrecei#er#A,AMNho!e network3orei0nnetworksender',. Sender sends to the I- addressof the recei#er as "s"al25& wor0s as defa"lt ro"terSo"rce: SchillerCNSridhar Iyer IIT Bombay 112Mobile I-: Basic !peration&gent &d#ertisementA :&/5& periodically send ad#ertisement messages into their physical s"bnetsA M' listens to these messages and detects2 if it is in home/foreign networ0A M' reads a .!& from the 5& ad#ertisement messagesM' Registration A M' signals .!& to the :& #ia the 5&A :& ac0nowledges #ia 5& to M'A limited lifetime2 need to be sec"red by a"thentication :& -roDyA :& ad#ertises the I- address of the M' =as for fiDed systems> A pac0ets to the M' are sent to the :& A independent of changes in .!&/5&-ac0et T"nnelingA :& to M' #ia 5&Sridhar Iyer IIT Bombay 113&gent ad#ertisementpreference le#el ,ro"ter address ,[addressestypeaddr. siHe lifetimechec0s"m.!& ,.!& +type seE"ence n"mber length*; ) ,8 ,M 6, +7 +6codepreference le#el +ro"ter address +. . . registration lifetime. . . R B : 5 M/ < reser#edSridhar Iyer IIT Bombay 114RegistrationtM':&registrationreE"estregistrationreplytM'5& :&registrationreE"estregistrationreE"estregistrationreplyregistrationreplySridhar Iyer IIT Bombay 11#Registration reE"esthome agenthome addresstype lifetime*; ) ,8 ,M 6, +7 +6rs#identification.!&eDtensions . . . SBFM/A t"nnel between :& and .!&Care-o3 address C@AI% address o3 ,ATT%I- identification)*-$n-)* I- chec0s"mflags fragment offsetlength T!S #er. I:%I% address o3 MNI% address o3 CNTT%I- identificationlay. 7 prot. I- chec0s"mflags fragment offsetlength T!S #er. I:%T.-/@F-/ ... payloadSridhar Iyer IIT Bombay 117Mobile I-: !ther Iss"esRe#erse T"nnelingAfirewalls permit only 3topological correct3 addressesAa pac0et from the M' encaps"lated by the 5& is now topological correct!ptimiHationsATriang"lar Ro"tingG :& informs sender the c"rrent location of M' A.hange of 5&G new 5& informs old 5& to a#oid pac0et loss2 old 5& now forwards remaining pac0ets to new 5&Sridhar Iyer IIT Bombay 118Mobile I- S"mmaryMobile node mo#es to new location&gent &d#ertisement by foreign agentRegistration of mobile node with home agent-roDying by home agent for mobile node(ncaps"lation of pac0etsT"nneling by home agent to mobile node #ia foreign agentRe#erse t"nneling!ptimiHations for triang"lar ro"tingSridhar Iyer IIT Bombay 119!"tlineIntrod"ction and !#er#iew $ireless %&'s: I((( )*+.,,Mobile I- ro"ting$C% o.er wireless/SM air interface/-RS networ0 architect"re$ireless application protocolMobile agentsMobile ad hoc networ0sSridhar Iyer IIT Bombay 120Transmission .ontrol -rotocol =T.->Reliable ordered deli#ery A&c0nowledgements and Retransmissions(ndCtoCend semanticsA&c0nowledgements sent to T.- sender confirm deli#ery of data recei#ed by T.- recei#erA&c0 for data sent only a3ter data has reached recei#erA."m"lati#e &c0Implements congestion a#oidance and controlSridhar Iyer IIT Bombay 121$indow Based 5low .ontrolSliding window protocol$indow siHe minim"m ofArecei#erKs ad#ertised window C determined by a#ailable b"ffer space at the recei#erAcongestion window C determined by the sender2 based on feedbac0 from the networ0+ 6 7 8 M ; ) 9 ,* ,, ,6 , ,+SenderKs window&c0s recei#ed 'ot transmittedSridhar Iyer IIT Bombay 122"2>(6'"'2'>" ' 2> 5 ( A 6Time (round trips)Congestion Window size (segments)S*o+ tartCo(,etio(a-oida()eS*o+ tart threho*d(Dample ass"mes that ac0s are not delayedBasic T.- Beha#io"rSridhar Iyer IIT Bombay 123T.-: Fetecting -ac0et %ossRetransmission timeo"tAInitiate Slow StartF"plicate ac0nowledgementsAInitiate 5ast Retransmit&ss"mes that &%% pac0et losses are d"e to congestionSridhar Iyer IIT Bombay 124T.- after Timeo"t"5'"'52"25Time (round trips)Congestion window (segments)ssthresh I )ssthresh I ,*cwnd I +*A3ter ti!eoutSridhar Iyer IIT Bombay 12#"2>(6'"Time (round trips)Window size (segments)./ter /at retra(mit a(d /at re)o-ery +i(do+ i0e ired1)ed i( ha*/2Recei#erKs ad#ertiHedwindowA3ter 3ast reco.er9T.- after 5ast RetransmitSridhar Iyer IIT Bombay 126Impact of Transmission (rrors$ireless channel may ha#e b"rsty random errorsB"rst errors may ca"se timeo"tRandom errors may ca"se fast retransmitT.- cannot disting"ish between pac0et losses d"e to congestion and transmission errors@nnecessarily red"ces congestion windowThro"ghp"t s"ffersSridhar Iyer IIT Bombay 127Split .onnection &pproach(ndCtoCend T.- connection is bro0en into one connection on the wired part of ro"te and one o#er wireless part of the ro"te.onnection between wireless host M: and fiDed host 5: goes thro"gh base station BS5:CM: I 5:CBSSBSCM:FH MH BSBase Station Mobile :ost5iDed :ostSridhar Iyer IIT Bombay 128ICT.-: Split .onnection &pproachwirelessphysicallin0networ0transportapplicationphysicallin0networ0transportapplicationphysicallin0networ0transportapplicationrDmt-erCT.- connection stateT.- connectionT.- connectionSridhar Iyer IIT Bombay 129Snoop -rotocolB"ffers data pac0ets at the base station BSAto allow lin0 layer retransmission$hen d"pac0s recei#ed by BS from M:Aretransmit on wireless lin02 if pac0et present in b"fferAdrop d"pac0-re#ents fast retransmit at T.- sender 5:FH MH BSSridhar Iyer IIT Bombay 130Snoop -rotocol5: M: BSwirelessphysicallin0networ0transportapplicationphysicallin0networ0transportapplicationphysicallin0networ0transportapplicationrDmt-er T.-Cconnection stateT.- connectionSridhar Iyer IIT Bombay 131Impact of :andoffsSplit connection approachA hard state at base station m"st be mo#ed to new base stationSnoop protocolA soft state need not be mo#edA while the new base station b"ilds new state2 pac0et losses may not be reco#ered locally5reE"ent handoffs a problem for schemes that rely on significant amo"nt of hard/soft state at base stationsA hard state sho"ld not be lostA soft state needs to be recreated to benefit performanceSridhar Iyer IIT Bombay 132MCT.-Similar to the split connection approach2 MCT.- splits one T.- connection into two logical partsAthe two parts ha#e independent flow control as in ICT.-The BS does not send an ac0 to M:2 "nless BS has recei#ed an ac0 from M:Amaintains endCtoCend semanticsBS withholds ac0 for the last byte ac0Kd by M:FH MH BS&c0 ,*** &c0 999Sridhar Iyer IIT Bombay 133MCT.-$hen a new ac0 is recei#ed with recei#erKs ad#ertised window I *2 the sender enters persist modeSender does not send any data in persist modeAeDcept when persist timer goes off$hen a positi#e window ad#ertisement is recei#ed2 sender eDits persist mode!n eDiting persist mode2 RT! and cwnd are same as before the persist modeSridhar Iyer IIT Bombay 1345reeHeT.-MCT.- needs help from base stationABase station withholds ac0 for one byteAThe base station "ses this ac0 to send a Hero window ad#ertisement when a mobile host mo#es to another cell#reeBe$C% reE"ires the recei#er to send Hero window ad#ertisement =\$&>5: M: BSMobileT.- recei#erSridhar Iyer IIT Bombay 13#T.- o#er wireless s"mmary&ss"ming that pac0et loss implies congestion is in#alid in wireless mobile en#ironmentsIn#o0ing congestion control in response to pac0et loss is in appropriateSe#eral proposals to adapt T.- to wireless en#ironmentsModifications atA5iDed :ostABase StationAMobile :ostSridhar Iyer IIT Bombay 136!"tlineIntrod"ction and !#er#iew $ireless %&'s: I((( )*+.,, Mobile I- ro"tingT.- o#er wirelessGSM air inter3ace/-RS networ0 architect"re$ireless application protocolMobile agentsMobile ad hoc networ0sSridhar Iyer IIT Bombay 137/SM: System &rchitect"reSridhar Iyer IIT Bombay 138Base Transcei#er Station =BTS>!ne per cell.onsists of high speed transmitter and recei#er5"nction of BTSA-ro#ides two channelSignalling and Fata .hannelMessage sched"lingRandom access detectionA-erforms error protection coding for the radio channel G Rate adaptationIdentified by BTS Identity .ode =BSI.>Sridhar Iyer IIT Bombay 139Base Station .ontroller =BS.>.ontrols m"ltiple BTS .onsists of essential control and protocol intelligence entities5"nctions of BS.A-erforms radio reso"rce managementA &ssigns and releases freE"encies and time slots for all the MSs in its areaA Reallocation of freE"encies among cellsA :and o#er protocol is eDec"ted hereATime and freE"ency synchroniHation signals to BTSsATime Felay Meas"rement and notification of an MS to BTSA-ower Management of BTS and MSSridhar Iyer IIT Bombay 140Mobile Switching .enter =MS.>Switching node of a -%M'&llocation of radio reso"rce =RR>A:ando#er Mobility of s"bscribersA%ocation registration of s"bscriberThere can be se#eral MS. in a -%M'Sridhar Iyer IIT Bombay 141/ateway MS. =/MS.>.onnects mobile networ0 to a fiDed networ0A(ntry point to a -%M'@s"ally one per -%M'ReE"est ro"ting information from the :%R and ro"tes the connection to the local MS.Sridhar Iyer IIT Bombay 142&ir Interface: -hysical .hannel@plin0/Fownlin0 of +8M:HA )9* C9,8 M:H for @p lin0A968 C 9M* M:H for Fown lin0.ombination of freE"ency di#ision and time di#ision m"ltipleDingA5FM&A ,+7 channels of +** 0:HA +** 0:H g"ard bandATFM&A B"rstMod"lation "sed /a"ssian Minim"m Shift Keying =/MSK>Sridhar Iyer IIT Bombay 143Sridhar Iyer IIT Bombay 144B"rstsB"ilding "nit of physical channelTypes of b"rstsA'ormalASynchroniHationA5reE"ency .orrectionAF"mmyA&ccessSridhar Iyer IIT Bombay 14#'ormal B"rst'ormal B"rstA+]=6 head bit S 8; data bits S , signaling bit> S +M training seE"ence bit S ).+8 g"ard bitA@sed for all eDcept R&.:2 5S.: O S.:Sridhar Iyer IIT Bombay 146&ir Interface: %ogical .hannelTraffic .hannel =T.:>Signaling .hannelABroadcast .hannel =B.:>A.ommon .ontrol .hannel =..:>AFedicated/&ssociated .ontrol .hannel =F..:/&..:>Sridhar Iyer IIT Bombay 147Sridhar Iyer IIT Bombay 148Traffic .hannelTransfer either encoded speech or "ser dataBidirectional5"ll Rate T.:ARate ++.70bpsABm interface:alf Rate T.:ARate ,,.+ 0bpsA%m interfaceSridhar Iyer IIT Bombay 1495"ll Rate Speech .odingSpeech .oding for +*ms segmentsA+M* bits at the o"tp"t A(ffecti#e data rate ,60bps@neE"al error protectionA,)+ bits are protected G 8* S ,6+ bits I ,)+ bitsA;) bits "nprotected.hannel (ncoding A.odes +M* bits into =) D 8; bit bloc0s> 78M bitsInterlea#ingA+ bloc0s of different set interlea#ed on a normal b"rst =sa#e damages by error b"rsts>Sridhar Iyer IIT Bombay 1#034 8 76 5 1 21268.253 57Speech20 ms20 ms1 57 3260 260456 bit456 bitSpeech CoderSpeech CoderChannel EncodingChannel EncodingInterleavingNORMAL BURSTOut of first 20 msOut of second 20msSridhar Iyer IIT Bombay 1#1TTraffic Channel Structure for Full Rate Coding234 1 8 7 6 543 2 1 8 76 5 1 21 23 4567 89 10111213 14 15 16 17 26TTT T T T TT TTT TST T TT ISlotsBursts for Users allocated in SlotT = TrafficS = Signal( contains information about the signal strength in neighboring cells)Sridhar Iyer IIT Bombay 1#2TTraffic Channel Structure for Half Rate CodingT234 1 8 7 6 543 2 1 8 76 5 1 21 23 4567 89 10111213 14 15 16 17 26T T TTTTS TTSlotsBurst for one users T =1 23 4567 89 10111213 14 15 16 17 26T T TT T T T TSBursts for another users allocatedin alternate SlotsSridhar Iyer IIT Bombay 1#3B..:Broadcast .ontrol .hannel =B..:>ABTS to MSARadio channel config"ration A ."rrent cell S 'eighbo"ring cellsASynchroniHing informationA 5reE"encies S frame n"mberingARegistration Identifiers A %& S .ell Identification =.I> S Base Station Identity .ode =BSI.>Sridhar Iyer IIT Bombay 1#45..: O S.:5reE"ency .orrection .hannel ARepeated broadcast of 5BSynchroniHation .hannel ARepeated broadcast of SBAMessage format of S.:PLMN color 3 bitsBS color 3 bitsT1 Superframeindex 11 bitsT2 multiframe index 11 bitsT3 block frameindex 3bitsBSIC 6 bits"FN 19bitsSridhar Iyer IIT Bombay 1##R&.: O SF..:Random &ccess .hannel =R&.:>AMS to BTSASlotted &lohaAReE"est for dedicated SF..:Standalone Fedicated .ontrol .hannel =SF..:>AMS BTSAStandaloneB Independent of T.:Sridhar Iyer IIT Bombay 1#6&/.: O -.:&ccess /rant .hannel =&/.:>ABTS to MSA&ssign an SF..:/T.: to MS-aging .hannel =-.:> ABTS to MSA-age MSSridhar Iyer IIT Bombay 1#7S&..: O 5&..:Slow &ssociated .ontrol .hannel =S&..:>AMS BTSA&lways associated with either T.: or SF..:AInformationA !ptimal radio operationB .ommands for synchroniHationA Transmitter power controlB .hannel meas"rement ASho"ld always be acti#eB as proof of eDistence of physical radio connection5ast &ssociated .ontrol .hannel =5&..:> AMS BTSA :ando#erA -reCempti#e m"ltipleDing on a T.:2 Stealing 5lag =S5>Sridhar Iyer IIT Bombay 1#8(Dample: Incoming .all Set"pMS BSS/MS.CCCCCC-aging reE"est=-.:>MS BSS/MS. CCCCCC .hannel reE"est=R&.:>MS BSS/MS.CCCCCC Immediate &ssignment =&/.:>MS BSS/MS. CCCCCC -aging Response =SF..:>MS BSS/MS.CCCCCC &"thentication ReE"est =SF..:>MS BSS/MS. CCCCCC &"thentication Response =SF..:>MS BSS/MS.CCCCCC .ipher Mode .ommand =SF..:>MS BSS/MS. CCCCCC .ipher Mode .ompl.=SF..:>MS BSS/MS.CCCCCC Set"p=SF..:>MS BSS/MS. CCCCCC .all .onfirmation =SF..:>MS BSS/MS.CCCCCC &ssignment .ommand =SF..:>MS BSS/MS. CCCCCC &ssignment .ompl. =5&..:>MS BSS/MS. CCCCCC &lert=5&..:>MS BSS/MS. CCCCCC .onnect =5&..:>MS BSS/MS.CCCCCC .onnect &c0nowledge =5&..:>MS BSS/MS.CCCCCC Fata =T.:>Sridhar Iyer IIT Bombay 1#9YESNONONOYESYESPower On Scan Channels,monitor RF levelsSelect the channel with highest RF level among the control channelsScan the channel for theFCCHIsFCCH detected?Scan channel for SCHIsSCH detected?Read data from BCCHand determine is it BCCH?Isthe current BCCHchannel included?Camp on BCCH and start decodingSelect the channel withnext highest Rf level fromthe control list.From the channel dataupdate the control channel listSridhar Iyer IIT Bombay 160&dapti#e 5rame SynchroniHationTiming &d#ance&d#ance in TD time corresponding to propagation delayM bit n"mber "sedB hence M6 stepsM6 bit period I +66 micro seconds =ro"nd trip time>A68 KmsSridhar Iyer IIT Bombay 161Sridhar Iyer IIT Bombay 162/SM: .hannel Mapping S"mmary%ogical channelsA Traffic .hannelsB .ontrol .hannels-hysical .hannelA Time Slot '"mberB TFM& frameB R5 .hannel SeE"enceMapping in freE"encyA ,+7 channels2 +**K:H spacingMapping in timeA TFM& 5rame2 M"lti 5rame2 S"per 5rame2 .hannelA Two 0inds of m"ltiframe: A +MCframe m"ltiframeB "sage CSpeech and FataA 8,Cframe m"ltiframeB "sage CSignallingSridhar Iyer IIT Bombay 1631 Hyper frame = 2048 Super frames =2715648 TDMA frames ( 3h 28 min 53 sec 760 ms) 1 Super frame = 1326 TDMA frames (6.12s)= 51(26 frames) Multi frame1(26 frames) Multi frame = 26 TDMA frames (120 ms) 0 12 3 2045 2046 20470 12 34 57 601 230 1235023 24254950T0 T1I 12T23T12(SACCH)T23 0 1 Super frame = 1326 TDMA frames (6.12s)=26(51 frames) Multi frameSridhar Iyer IIT Bombay 164!"tlineIntrod"ction and !#er#iew $ireless %&'s: I((( )*+.,, Mobile I- ro"tingT.- o#er wireless/SM air interfaceG%&S network architecture$ireless application protocolMobile agentsMobile ad hoc networ0sSridhar Iyer IIT Bombay 16#/SM architect"reSo1r)e3 Betttetter et2 a*2Sridhar Iyer IIT Bombay 166/SM m"ltiple accessSridhar Iyer IIT Bombay 167/SM call ro"ting'7 MSISDN27 MSISDN:/&,/&A)C*I&GMSCCIW#MSCBSCBSCB$SB$SB$SISDN7 MS&N>7 MS&N57 MS&N(7 $MSIA7 $MSIA7 $MSIA7 $MSI67 $MSI/A2/A'MSMSSridhar Iyer IIT Bombay 168!ptions for data transferTwo enhancements to /SM for dataA:S.SF C :igh Speed .irc"it Switched FataA/-RS C /eneral -ac0et Radio Ser#iceBoth ha#e capacity to "se new coding schemes and to ma0e m"ltislot allocation/-RS2 being a pac0et switched ser#ice2 is 0nown to be more efficient and fleDible for data transfer p"rposesIt deli#ers circ"it and pac0etCswitched ser#ices in one mobile radio networ0Sridhar Iyer IIT Bombay 169/-RS feat"resRadio reso"rces are allocated for only one or a few pac0ets at a time2 so /-RS enablesAmany "sers to share radio reso"rces2 and allow efficient transport of pac0etsAfast set"p/access timesAconnecti#ity to eDternal pac0et data n/wA#ol"meCbased charging/-RS also carries SMS in data channels rather than signaling channels as in /SMSridhar Iyer IIT Bombay 170/-RS &rchitect"reSridhar Iyer IIT Bombay 171/-RS &rchitect"reReE"ires addition of a new class of nodes called /S's =/-RS S"pport 'odes>AS/S': Ser#ing /-RS S"pport 'ode2A//S': /ateway /-RS S"pport 'odeBS. reE"ires a -.@ =-ac0et .ontrol @nit> and #ario"s other elements of the /SM n/w reE"ire software "pgrades &ll /S's are connected #ia an I-Cbased bac0bone. -rotocol data "nits =-F@s> are encaps"lated and t"nneled between /S'sSridhar Iyer IIT Bombay 172//S'Ser#es as the interface to eDternal I- networ0s which see the //S' as an I- ro"ter ser#ing all I- addresses of the MSs//S' stores c"rrent S/S' address and profile of the "ser in its location registerIt t"nnels protocol data pac0ets to and from the S/S' c"rrently ser#ing the MSIt also performs a"thentication and charging//S' can also incl"de firewall and pac0etCfiltering mechanismsSridhar Iyer IIT Bombay 173S/S'&nalog of the MS. in /SM Ro"tes incoming and o"tgoing pac0ets addressed to and from any /-RS s"bscriber located within the geographical area ser#ed by the S/S'%ocation Register of the S/S' stores information =e.g. c"rrent cell and and "ser profiles =e.g. IMSI2 addresses> of all /-RS "sers registered with this S/S'Sridhar Iyer IIT Bombay 174BS. and othersBS. m"st get a -ac0et .ontrol @nit toAset "p2 s"per#ise and disconnect pac0etCswitched callsAalso s"pport cell change2 radio reso"rce config"ration and channel assignmentMS./

Enter na*e@

%#%%##%#%%####%##%%#%%##%##%##%###%#%#%%#%%##%#%.ontent encoding,$$%C,$M/WA%*ource+ $&- 5or"mSridhar Iyer IIT Bombay 190$:U $&-Z$ireless networ0s and phones A ha#e specific needs and reE"irementsA not addressed by eDisting Internet technologies$&-A (nables any data transport G T.-/I-2 @F-/I-2 /@TS =ISC,68/M>2 SMS2 or @SSF.A !ptimiHes the content and airClin0 protocolsA @tiliHes plain $eb :TT- ,., ser#ersG "tiliHes standard Internet mar0"p lang"age technology =^M%> G all $M% content is accessed #ia :TT- ,., reE"estsA $M% @I components map well onto eDisting mobile phone @IG no reCed"cation of the endC"sersG le#eraging mar0et penetration of mobile de#icesSridhar Iyer IIT Bombay 191$&-: main feat"resBrowserA 3Micro browser42 similar to eDisting web browsersMar0"p lang"ageA Similar to :TM%2 adapted to mobile de#ices Script lang"ageA Similar to 1a#ascript2 adapted to mobile de#ices /atewayA Transition from wireless to wired worldSer#erA 3$ap/!rigin ser#er42 similar to eDisting web ser#ers-rotocol layersA Transport layer2 sec"rity layer2 session layer etc.Telephony application interfaceA &ccess to telephony f"nctionsSridhar Iyer IIT Bombay 192Internet model,T#L,TTPTL*-**LTCP-.PSridhar Iyer IIT Bombay 193Web ServerContentC9IS)ri'tet)2$ML 8e);

+ith $ML5S)ri'tWAP Gateway$ML %()oder$MLS)ri'tCom'i*er!roto)o* .da'terCient$ML$ML5S)ri't$T.I%t)2HTT! $S!S(.C.reate.res=S'M2 KR2 SIF2 K(SX2 .SX2 .MX>S(.C(Dchange.reES(.C(Dchange.indS(.C(Dchange.res=..>S(.C.ommit.reES(.C(Dchange.cnf=..>S(.C.ommit.indS(.C.ommit.cnfSo"rce: Schiller&%S" &ey %'!(ange SuiteCS" Cip(er SuiteC)" Compression )odeS*)" Se+uen!e *umber )ode&," &ey ,e-res( Cy!eS.#" Session .denti-ierCC" Cient Certi-i!ateSridhar Iyer IIT Bombay 204$T-: $ireless Transaction -rotocol/oalsAdifferent transaction ser#ices that enable applications to select reliability2 efficiency le#elsAlow memory reE"irements2 s"ited to simple de#ices =N ,*0byte >Aefficiency for wireless transmission$T-As"pports peerCtoCpeer2 client/ser#er and m"lticast applicationsAefficient for wireless transmissionAs"pport for different comm"nication scenariosSridhar Iyer IIT Bombay 20#$T- transactionsclass *+ "nreliable message transferA "nconfirmed In#o0e message with no Res"lt messageA a datagram that can be sent within the conteDt of an eDisting Sessionclass ,+ reliable message transfer witho"t res"lt messageA confirmed In#o0e message with no Res"lt messageA "sed for data p"sh2 where no response from the destination is eDpectedclass ++ reliable message transfer with eDactly one reliable res"lt messageA confirmed In#o0e message with one confirmed Res"lt messageA a single reE"est prod"ces a single replySridhar Iyer IIT Bombay 206$T-: ser#ices and protocols$T- =Transaction>Apro#ides reliable data transfer based on reE"est/reply paradigmG no eDplicit connection set"p or tear downG optimiHed set"p =data carried in first pac0et of protocol eDchange>G see0s to red"ce 6Cway handsha0e on initial reE"estAs"pportsG header compressionG segmentation /reCassemblyG retransmission of lost pac0etsG selecti#eCretransmissionG port n"mber addressing =@F- ports n"mbers>G flow controlSridhar Iyer IIT Bombay 207$T- ser#ices message oriented =not stream>s"pports an &bort f"nction for o"tstanding reE"estss"pports concatenation of -F@ss"pports two ac0nowledgement optionsA@ser ac0nowledgement Aac0s may be forced from the $T- "ser ="pper layer>AStac0 ac0nowledgement: defa"ltSridhar Iyer IIT Bombay 208$T- .lass * TransactionTRCIn#o0e.reE=S&2 S-2 F&2 F-2 &2 @F2 .I*2 :>In#o0e -F@TRCIn#o0e.ind=S&2 S-2 F&2 F-2 &2 @F2 .I*2 :X>initiatorTRCS&-responderTRCS&-So"rce: SchillerA" A!/nowedgement Type (WTP0$ser)C" Cass (12122)3" 3ande (so!/et aias)Sridhar Iyer IIT Bombay 209$T- .lass , Transaction2 no "ser ac0 O "ser ac0TRCIn#o0e.reE=S&2 S-2 F&2 F-2 &2 @F2 .I,2 :>In#o0e -F@TRCIn#o0e.ind=S&2 S-2 F&2 F-2 &2 @F2 .I,2 :X>initiatorTRCS&-responderTRCS&-&c0 -F@TRCIn#o0e.res=:X>TRCIn#o0e.cnf=:>TRCIn#o0e.reE=S&2 S-2 F&2 F-2 &2 @F2 .I,2 :>In#o0e -F@TRCIn#o0e.ind=S&2 S-2 F&2 F-2 &2 @F2 .I,2 :X>initiatorTRCS&-responderTRCS&-&c0 -F@TRCIn#o0e.cnf=:>So"rce: SchillerSridhar Iyer IIT Bombay 210$T- .lass + Transaction2no "ser ac02 no hold onTRCIn#o0e.reE=S&2 S-2 F&2 F-2 &2 @F2 .I+2 :>In#o0e -F@TRCIn#o0e.ind=S&2 S-2 F&2 F-2 &2 @F2 .I+2 :X>initiatorTRCS&-responderTRCS&-Res"lt -F@TRCRes"lt.reE=@F]2 :X>TRCRes"lt.ind=@F]2 :>&c0 -F@TRCIn#o0e.cnf=:>TRCRes"lt.res=:>TRCRes"lt.cnf=:X>So"rce: SchillerSridhar Iyer IIT Bombay 211$T- .lass + Transaction2 "ser ac0TRCIn#o0e.reE=S&2 S-2 F&2 F-2 &2 @F2 .I+2 :>In#o0e -F@TRCIn#o0e.ind=S&2 S-2 F&2 F-2 &2 @F2 .I+2 :X>initiatorTRCS&-responderTRCS&-Res"lt -F@ TRCRes"lt.ind=@F]2 :>&c0 -F@TRCIn#o0e.res=:X>TRCIn#o0e.cnf=:>&c0 -F@TRCRes"lt.reE=@F]2 :X>TRCRes"lt.res=:>TRCRes"lt.cnf=:X>So"rce: SchillerSridhar Iyer IIT Bombay 212$S- C $ireless Session -rotocol/oalsA :TT- ,., f"nctionalityG ReE"est/reply2 content type negotiation2 ...A s"pport of client/ser#er transactions2 p"sh technologyA 0ey management2 a"thentication2 Internet sec"rity ser#ices$S- Ser#icesA pro#ides shared state between client and ser#er2 optimiHes content transferA session management =establish2 release2 s"spend2 res"me>A efficient capability negotiationA content encodingA -"shSridhar Iyer IIT Bombay 213$S- o#er#iew:eader (ncodingA compact binary encoding of headers2 content type identifiers and other wellC0nown teDt"al or str"ct"red #al"esA red"ces the data act"ally sent o#er the networ0.apabilities =are defined for>:A message siHe2 client and ser#erA protocol options: .onfirmed -"sh 5acility2 -"sh 5acility2 Session S"spend 5acility2 &c0nowledgement headersA maDim"m o"tstanding reE"estsA eDtended methodsS"spend and Res"meA ser#er 0nows when client can accept a p"shA m"ltiCbearer de#icesA dynamic addressingA allows the release of "nderlying bearer reso"rcesSridhar Iyer IIT Bombay 214$S-/B session establishmentSC.onnect.reE=S&2 .&2 .:2 R.>.onnect -F@SC.onnect.ind=S&2 .&2 .:2 R.>clientSCS&-ser#erSCS&-.onnReply -F@SC.onnect.res=S:2 '.>SC.onnect.cnf=S:2 '.>$T- .lass +transactionSo"rce: SchillerC3" Cient 3eader,C" ,e+uested CapabiitiesS3" Server 3eader*C" *egotiated CapabiitiesSridhar Iyer IIT Bombay 21#$S-/B session s"spend/res"meSCS"spend.reES"spend -F@SCS"spend.ind=R>clientSCS&-ser#erSCS&-Reply -F@SCRes"me.res$T- .lass +transactionSCS"spend.ind=R> SCRes"me.reE=S&2 .&>SCRes"me.ind=S&2 .&>Res"me -F@SCRes"me.cnf$T- .lass *transactionSo"rce: Schiller," ,eason -or dis!onne!tionSridhar Iyer IIT Bombay 216$S-/B session terminationFisconnect -F@SCFisconnect.ind=R>clientSCS&-ser#erSCS&-SCFisconnect.ind=R>$T- .lass *transactionSCFisconnect.reE=R>So"rce: SchillerSridhar Iyer IIT Bombay 217confirmed/nonCconfirmed p"shSC-"sh.reE=-:2 -B>clientSCS&-ser#erSCS&-.onf-"sh -F@$T- .lass ,transactionSC-"sh.ind=-:2 -B>SC.onfirmed-"sh.res=.-IF>SC.onfirmed-"sh.ind=.-IF2 -:2 -B>$T- .lass *transaction-"sh -F@SC.onfirmed-"sh.reE=S-IF2 -:2 -B>clientSCS&-ser#erSCS&-SC.onfirmed-"sh.cnf=S-IF>So"rce: SchillerP3" Pus( 3eaderPB" Pus( BodySP.#" Server Pus( .#CP.#" Cient Pus( .#Sridhar Iyer IIT Bombay 218$&- Stac0 S"mmary$F-A f"nctionality similar to @F- in I- networ0s$T%SA f"nctionality similar to SS%/T%S =optimiHed for wireless>$T-A .lass *: analogo"s to @F-A .lass ,: analogo"s to T.- =witho"t connection set"p o#erheads>A .lass +: analogo"s to R-. =optimiHed for wireless>A feat"res of 3"ser ac0nowledgement42 3hold on4$S-A $S-/B: analogo"s to http ,., =add feat"res of s"spend/res"me>Amethod: analogo"s to R-./RMIA feat"res of asynchrono"s in#ocations2 p"sh =confirmed/"nconfirmed>Sridhar Iyer IIT Bombay 219$ireless &pplication (n#ironment =$&(>/oalsAde#ice and networ0 independent application en#ironmentAfor lowCbandwidth2 wireless de#icesAconsiderations of slow lin0s2 limited memory2 low comp"ting power2 small display2 simple "ser interface =compared to des0tops>Aintegrated Internet/$$$ programming model Ahigh interoperabilitySridhar Iyer IIT Bombay 220$&( components&rchitect"reA &pplication model2 Microbrowser2 /ateway2 Ser#er@ser &gentsA $M%/$T&/!thersA content formats: #.ard2 #.alendar2 $ireless Bitmap2 $M%..$M%A ^M%CSyntaD2 based on card stac0s2 #ariables2 ...$M%ScriptA proced"ral2 loops2 conditions2 ... =similar to 1a#aScript>$T&A telephone ser#ices2 s"ch as call control2 teDt messages2 phone boo02 ... =accessible from $M%/$M%Script>-roDy =Method/-"sh>Sridhar Iyer IIT Bombay 221@ri0in Ser.ers$&(: logical modelwebser#erother contentser#erGatewa9Clientother$&("ser agents$M%"ser agent$T&"ser agent-"sh proDyencodedreE"estreE"estencodedresponsewithcontentresponsewithcontentp"shcontentencodedp"shcontentMethod proDyencodersOdecodersSridhar Iyer IIT Bombay 222$&- microbrowser!ptimiHed for wireless de#icesMinimal R&M2 R!M2 Fisplay2 .-@ and 0eys-ro#ides consistent ser#ice @I across de#ices-ro#ides Internet compatibility(nables wide array of a#ailable content and applicationsSridhar Iyer IIT Bombay 223$M%: $ireless Mar0"p %ang"ageTagCbased browsing lang"age:A Screen management =teDt2 images>A Fata inp"t =teDt2 selection lists2 etc.>A :yperlin0s O na#igation s"pportTa0es into acco"nt limited display2 na#igation capabilities of de#icesContent (XML)XSL ProcessorHTTP Browser,T#L *t$le*heetWML Browsers"#L *t$lesheetSridhar Iyer IIT Bombay 224$M%^M%Cbased lang"ageAdescribes only intent of interaction in an abstract mannerApresentation depends "pon de#ice capabilities.ards and Fec0sAdoc"ment consists of many cardsA@ser interactions are split into cardsA(Dplicit na#igation between cardsAcards are gro"ped to dec0sAdec0 is similar to :TM% page2 "nit of content transmission(#ents2 #ariables and state mgmtSridhar Iyer IIT Bombay 22#$M%The basic "nit is a card. .ards are gro"ped together into Decks Foc"mentFec0 ="nit of transfer>&ll dec0s m"st containA Foc"ment prolog"eG ^M% O doc"ment type declarationA N$M%J elementG M"st contain one or more cardsn="#)%"D>

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"#L &ile *tructureSridhar Iyer IIT Bombay 226$M% cardsInput*le!entsDeckCardNa.i0ation:ariaFtai@//F;/*cA%5G#4%$4H#7A calling a n"mber =$M%Script>BTAPC6+ic)*aIe!a++:"%5G#4%$4H#7"=AImplementationA (Dtension of basic $&( application modelA (Dtensions added to standard $M%/$M%Script browserA (Dposes additional &-I =$T&I>Sridhar Iyer IIT Bombay 228$T& feat"res(Dtension of basic $&( application modelAnetwor0 model for interactionG client reE"ests to ser#erG e#ent signaling: ser#er can p"sh content to the clientAe#ent handlingG table indicating how to react on certain e#ents from the networ0G client may now be able to handle "n0nown e#entsAtelephony f"nctionsG some application on the client may access telephony f"nctions Sridhar Iyer IIT Bombay 229$T& Interfacegeneric2 highCle#el interface to mobileKs telephony f"nctionsAsetting "p calls2 reading and writing entries in phoneboo0$T& &-I incl"desA.all controlA'etwor0 teDt messagingA-hone boo0 interfaceA(#ent processingSec"rity model: segregationASeparate $T& browserASeparate $T& portSridhar Iyer IIT Bombay 230Placing an outgoing call with WTAI:Input *le!entW$AI Call

'etwor0 .ommon $T&IA$T& ser#ice pro#ider is in operatorKs domainAall $T&I feat"res are accessible2 incl"ding the interface to $T& e#entsAlibrary f"nctionsG /lobal binding: A channel corresponding to the e#ent is stored in the repositoryA e#ent ca"ses eDec"tion of reso"rces defined by the channelA eDample: #oice mail ser#ice Temporary binding:A reso"rces to be eDec"ted are defined by the already eDec"ting ser#iceA eDample: yellow pages loo0"p and call establishmentSridhar Iyer IIT Bombay 243(#ent :andling =no ser#ice in eDec"tion>So"rce: :ei?denSridhar Iyer IIT Bombay 244(#ent :andling =ser#ice already eDec"tion>,: Temporary binding eDists+. 'o temporary binding and conteDt is protected6: 'o temporary binding and conteDt is not protectedSo"rce: :ei?denSridhar Iyer IIT Bombay 24#$&- -"sh Ser#ices$eb p"shA Sched"led p"ll by client =browser>G eDample: &cti#e .hannelsA no realCtime alerting/responseG eDample: stoc0 E"otes$ireless p"shA accomplished by "sing the networ0 itselfG eDample: SMSA limited to simple teDt2 cannot be "sed as starting point for ser#ice G eDample: if SMS contains news2 "ser cannot reE"est specific news item$&- p"shA'etwor0 s"pported p"sh of $M% contentG eDample: &lerts or ser#ice indicationsA -reCcaching of data =channels/reso"rces>Sridhar Iyer IIT Bombay 246$&- p"sh framewor0So"rce: :ei?denSridhar Iyer IIT Bombay 247-"sh &ccess -rotocolBased on reE"est/response model-"sh initiator is the client-"sh proDy is the ser#erInitiator "ses :TT- -!ST to send p"sh message to proDyInitiator sends control information as an ^M% doc"ment2 and content for mobile =as $M%>-roDy sends ^M% entity in response indicating s"bmission stat"sInitiator can A cancel pre#io"s p"shA E"ery stat"s of p"shAE"ery stat"s/capabilities of de#iceSridhar Iyer IIT Bombay 248-"sh -roDy /ateway$&- stac0 =comm"nication with mobile de#ice>T.-/I- stac0 =comm"nication with Internet p"sh initiator>-roDy layer doesA control information parsingA content transformationA session managementA client capabilitiesA store and forwardA prioritiHationA address resol"tionA management f"nctionSridhar Iyer IIT Bombay 249!#er the &ir =!T&> -rotocol(Dtends $S- with p"shCspecific f"nctionality&pplication IF "niE"ely identifies a partic"lar application in the client =referenced as a @RI>.onnectionCoriented mode A client informs proDy of application IFs in a session.onnectionless mode A well 0nown ports2 one for sec"re and other for nonCsec"re p"sh Session Initiation &pplication =SI&>A "nconfirmed p"sh from proDy to clientA reE"est to create a session for a specific "ser agent and bearerSridhar Iyer IIT Bombay 2#0$&( S"mmary$M% and $M% ScriptA analogo"s to :TM% and 1a#aScript =optimiHed for wireless>A microbrowser "ser agentB compiler in the networ0$T&A $T&I: different access rights for different applications/agentsA $T& @ser &gent =analogy with operating systems>G .onteDt A &cti#ation RecordG .hannel A Interr"pt :andlerG Reso"rce A Shared ro"tines in#o0ed by interr"pt handlersG Repository A %ibrary of interr"pt handlersA feat"re of dynamically p"shing the interr"pt handler before the e#ent -"shA no analogy in InternetSridhar Iyer IIT Bombay 2#1!"tlineIntrod"ction and !#er#iew $ireless %&'s: I((( )*+.,, Mobile I- ro"tingT.- o#er wireless/SM air interface/-RS networ0 architect"re$ireless application protocolMo:ybrid protocolsA &dapti#eB .ombination of proacti#e and reacti#eA (Dample : \R- =Hone ro"ting protocol>Sridhar Iyer IIT Bombay 268Fynamic So"rce Ro"ting =FSR>Ro"te Fisco#ery -hase:A Initiated by so"rce node S that wants to send pac0et to destination node FA Ro"te ReE"est =RR(P> floods thro"gh the networ0A (ach node appends own $dent$,$er when forwarding RR(PRo"te Reply -hase:A F on recei#ing the first RR(P2 sends a Ro"te Reply =RR(->A RR(- is sent on a ro"te obtained by re#ersing the ro"te appended to recei#ed RR(PA RR(- incl"des the ro"te from S to F on which RR(P was recei#ed by node FFata 5orwarding -hase:A S sends data to F by so"rce ro"ting thro"gh intermediate nodesSridhar Iyer IIT Bombay 269Ro"te Fisco#ery in FSRBAS*#,EDCGI;F?&epresents a node that has recei.ed &&*G 3or D 3ro! SMN/Sridhar Iyer IIT Bombay 270Ro"te Fisco#ery in FSRBAS*#,EDCGI;&epresents trans!ission o3 &&*GF?Broadcast trans!issionMN/HSIHJ8?I &epresents list o3 identi3iers appended to &&*GSridhar Iyer IIT Bombay 271Ro"te Fisco#ery in FSRBAS*#,EDCGI;G Node , recei.es packet &&*G 3ro! two nei0h