Efficient Routing in Packet-Radio Networks Using Link-State Information

Transcription

1 o5 Eiint Routing in Pkt-Rio Ntworks Using Link-Stt Inormtion J.J. Gri-Lun-Avs Computr Enginring Dprtmnt Univrsity o Cliorni Snt Cruz, Cliorni jj@s.us.u Mrlo Spohn Rootop Communitions Mountin Viw, Cliorni 9404 mrlo@rootop.om Astrt- W prsnt th sour-tr ptiv routing () protool, whih w show through simultion xprimnts to r mor iint thn th Dynmi Sour Routing () protool, whih hs n shown to on o th st prorming on-mn routing protools. A routr in ommunits to its nighors th prmtrs o its sour routing tr, whih onsists o h link tht th routr ns to rh vry stintion. To onsrv trnsmission nwith n nrgy, routr trnsmits hngs to its sour routing tr only whn th routr tts nw stintions, th possiility o looping, or th possiility o no ilurs or ntwork prtitions. I. INTRODUCTION Multi-hop pkt-rio ntworks, or -ho ntworks, onsist o moil hosts intronnt y routrs tht n lso mov. Th ploymnt o suh routrs is -ho n th topology o th ntwork is vry ynmi, us o host n routr moility, signl loss n intrrn, n powr outgs. In ition, th hnnl nwith vill in -ho ntworks is rltivly limit ompr to wir ntworks, n untthr routrs my n to oprt with ttry-li onstrints. Routing lgorithms or -ho ntworks n tgoriz oring to th wy in whih routrs otin routing inormtion, n oring to th typ o inormtion thy us to omput prrr pths. In trms o th wy in whih routrs otin inormtion, routing protools hv n lssii s tl-rivn n on-mn. In trms o th typ o inormtion us y routing protools, routing protools n lssii into link-stt protools n istn-vtor protools. Routrs running link-stt protool us topology inormtion to mk routing isions; routrs running istn-vtor protool us istns n, in som ss, pth inormtion, to stintions to mk routing isions. In n on-mn routing protool, routrs mintin pth inormtion or only thos stintions tht thy n to ontt s sour or rly o inormtion. Th si pproh onsists o llowing routr tht os not know how to rh stintion to sn loo-srh mssg to otin th pth inormtion it ns. Th irst routing protool o this typ ws propos to stlish virtul iruits in th MSE ntwork [9], n thr r svrl mor rnt xmpls o this pproh (.g., AODV [3], [7], TORA []). Th Dynmi Sour Routing () protool hs n shown to outprorm mny othr onmn routing protools [2]. All o th on-mn routing protools rport to t r s on istns to stintions, n thr hv n no on-mn link-stt proposls to t. In tl-rivn lgorithm, h routr mintins pth inormtion or h known stintion in th ntwork n upts its routing-tl ntris s n. Exmpls o tl-rivn lgorithms s on is- This work ws support in prt t UCSC y th Dns Avn Rsrh Projts Agny (DAR PA) unr Grnt F tn vtors r th routing protool o th DARPA pkt-rio ntwork [8], DSDV [2], WRP [5], n WIRP [4]. Prior tl-rivn pprohs to link-stt routing in pkt-rio ntworks r s on topology rost. Howvr, issminting omplt link-stt inormtion to ll routrs inurs xssiv ommunition ovrh in n -ho ntwork us o th ynmis o th ntwork n th smll nwith vill. Aoringly, ll link-stt routing pprohs or pkt-rio ntworks hv n s on hirrhil routing shms [4], [6]. To t, th t on whthr tl-rivn or n on-mn routing pproh is st or wirlss ntworks hs ssum tht tlrivn routing nssrily hs to provi optimum (.g., shortst-pth) routing, whn in t on-mn routing protools nnot nsur optimum pths. In this ppr, w introu th sour-tr ptiv routing () protool, whih is th irst xmpl o tl-rivn routing protool tht is mor iint thn ny on-mn routing protool y xploiting link-stt inormtion n llowing pths tkn to stintions to vit rom th optimum in orr to sv nwith. Furthrmor, n us with istriut hirrhil routing shms propos in th pst or oth istn-vtor or link-stt routing. Stion II sris, n Stion III omprs s prormn ginst th prormn o, whih hs n shown to inur th lst ovrh mong svrl on-mn routing protools [2]. A. Ovrviw II. DESCRIPTION In, h routr rports to its nighors th hrtristis o vry link it uss to rh stintion. Th st o links us y routr in its prrr pth to stintions is ll th sour tr o th routr. A routr knows its jnt links n th sour trs rport y its nighors; th ggrgtion o routr s jnt links n th sour trs rport y its nighors onstitut prtil topology grph. Th links in th sour tr n topology grph must jnt links or links rport y t lst on nighor. Th routr uss th topology grph to gnrt its own sour tr. Eh routr rivs routing tl spiying th sussor to h stintion y running lol rout-sltion lgorithm on its sour tr. Although ny typ o lol rout-sltion lgorithm n us in, w sri ssuming tht Dijkstr s shortst-pth irst (SPF) lgorithm is us t h routr to omput prrr pths. A routr running sns upts on its sour tr to its nighors only whn it loss ll pths to on or mor stintions, whn it tts nw stintion, or whn it trmins tht lol hngs to its sour tr n potntilly rt long trm routing loops. Bus h routr ommunits its sour tr to its nighors, th ltion o link no longr us to rh stintion is impliit with th ition o th nw link us to rh th stintion n n not snt xpliitly s n upt; routr mks xpliit rrn to il link only whn th ltion o link uss th routr to hv no pths to

2 2o5 on or mor stintions, in whih s th routr nnot provi nw links to mk th ltion o th il link impliit. Th si upt unit us in to ommunit hngs to sour trs is th link-stt upt (LSU). An LSU or link (u; v) in n upt mssg is tupl (u; v; l; sn) rporting th hrtristis o th link, whr l rprsnts th ost o th link n sn is th squn numr ssign to th LSU; n upt mssg ontins on or mor LSUs. For link twn routr u n routr or stintion v, routr u is ll th h no o th link in th irtion rom u to v. Th h no o link is th only routr tht n rport hngs in th prmtrs o tht link. LSUs r vlit using squn numrs, routr riving n LSU pts th LSU s vli i th riv LSU hs lrgr squn numr thn th squn numr o th LSU stor rom th sm sour, or i thr is no ntry or th link in th topology grph n th LSU is not rporting n ininit ost. Link-stt inormtion or il links r th only LSUs rs rom th topology grph u to ging (whih is in th orr o n hour tr hving pross th LSU). LSUs or oprtionl links r rs rom th topology grph whn th links r rs rom th sour tr o ll th nighors. W not tht, us LSUs or oprtionl links nvr g out, thr is no n or th h no o link to sn prioi LSUs to upt th squn numr o th link. This is vry importnt, us it mns tht os not n prioi upt mssgs to vlit link-stt inormtion lik OSPF [0] n vry singl routing protool s on squn numrs or tim stmps os! To simpliy our sription, th spiition in th rst o this ppr sris s i unoun ountrs wr vill to kp trk o squn numrs. An unrlying protool, whih w ll th nighor protool, ssurs tht routr tts within init tim th xistn o nw nighor n th loss o onntivity with nighor, n provis th rlil trnsmission o upt mssgs gnrt y to th nighors o th routr. All mssgs, hngs in th ost o link, link ilurs, n nw-nighor notiitions r pross on t tim within init tim n in th orr in whih thy r tt. Routrs r ssum to oprt orrtly, n inormtion is ssum to stor without rrors. Th ost o il link is onsir to ininity. B. Exhnging Upt Mssgs W n istinguish twn two min pprohs to upting routing inormtion in th routing protools tht hv n sign or wirlss ntworks: th optimum routing pproh (ORA) n th lstovrh routing pproh (LORA). With ORA, th routing protool ttmpts to upt routing tls s quikly s possil to provi pths tht r optimum with rspt to in mtri. In ontrst, with LORA, th routing protool ttmpts to provi vil pths oring to givn prormn mtri, whih n not optimum, to inur th lst mount o ontrol tri. On-mn routing protools suh s ollow LORA. Intrstingly, ll th tl-rivn routing protools rport to t or -ho ntworks hr to ORA, n mittly hv n pttions o routing protools vlop or wir ntworks; is th irst tlrivn routing protool tht implmnts LORA. In n on-mn routing protool, routr n kp using pth oun s long s th pth ls to th stintion, vn i th pth os not hv optimum ost. A similr pproh is us in, us h routr hs omplt pth to vry stintion s prt o its sour tr. A routr i running shoul sn upt mssgs oring to th ollowing thr ruls, whih inorm routrs o unrhl stintions, nw stintions, n upt topology inormtion to prvnt prmnnt routing loops. Routr i implmnts ths ruls y ompring its sour tr ginst th sour trs it hs riv rom its nighors. LORA-: Routr i ins nw stintion, or ny o its nighors rports nw stintion. Whnvr routr hrs rom nw nighor tht is lso nw stintion, it sns n upt mssg tht inlus th nw LSUs in its sour tr. Oviously, whn routr is irst initiliz or tr root, th routr itsl is nw stintion n shoul sn n upt mssg to its nighors. Link-lvl support shoul us or th routr to know its nighors within short tim, n thn rport its links to thos nighors with LSUs snt in n upt mssg. Els, simpl wy to implmnt n initiliztion tion onsists o rquiring th routr to listn or som tim or nighor tri, so tht it n tt th xistn o links to nighors. LORA-2: At lst on stintion oms unrhl to routr i or ny o its nighors. Whn routr prosss n input vnt (.g., link ils, n upt mssg is riv) tht uss ll its pths through ll its nighors to on or mor stintion to svr, th routr sns n upt mssg tht inlus n LSU spiying n ininit ost or th link onnting to th h o h sutr o th sour tr tht oms unrhl. Th upt mssg os not hv to inlu n LSU or h no in n unrhl sutr, us nighor riving th upt mssg hs th sning no s sour tr n n thror inr tht ll nos low th root o th sutr r lso unrhl, unlss LSUs r snt or nw links us to rh som o th nos in th sutr. LORA-3: This rul hs thr prts:. A pth impli in th sour tr o routr i ls to loop. 2. Th nw sussor hosn to givn stintion hs n rss lrgr thn th rss o routr i. 3. Th rport istn rom th nw hosn sussor n to stintion j is longr thn th rport istn rom th prvious sussor to th sm stintion. Howvr, i th link (i; j) ils n n is nighor o j, no upt mssg is n rgring j or ny stintion whos pth rom i involvs j. Eh tim routr prosss n upt mssg rom nighor, it upts tht nighor s sour tr n trvrss tht tr to trmin or whih stintions its nighor uss th routr s rly in its prrr pths. Th routr thn trmins i it is using th sm nighor s rly or ny o th sm stintions. A routing loop is tt i th routr n nighor us h othr s rly to ny stintion, in whih s th loop must rokn n th routr must sn n upt mssg with th orrsponing hngs. To xplin th n or th son prt o LORA-3, w osrv tht, in ny routing loop mong routrs with uniqu rsss, on o th routrs must hv th smllst rss in th loop; thror, i routr is or to sn n upt mssg whn it hooss sussor whos rss is lrgr thn its own, thn it is not possil or ll routrs in routing loop to rmin quit tr hoosing on nothr, us t lst on o thm is or to sn n upt mssg, whih uss th loop to rk whn routrs upt thir sour trs. Th lst prt o LORA-3 is n whn link osts n ssum irnt vlus in irnt irtions, in whih s th son prt o LORA-3 my not sui to rk loops us th no with th smllst rss in th loop my not hv to hng sussors whn th loop is orm. Th ollowing xmpl illustrts this snrio. Consir th six-no wirlss ntwork shown in Figur n ssum

3 3o5 tht th thir prt o LORA-3 is not in t t th routrs running. In this xmpl, nos r givn intiirs tht r lxiogrphilly orr, i.., is th smllst intiir n is th lrgstintiir in th grph. All links n nos r ssum to hv th sm propgtion lys, n ll th links ut link (; ) hv unit ost. Figurs () through () show th sour trs oring to t th routrs init with ill irls or th ntwork topology pit in Figur (). Arrowhs on soli lins init th irtion o th links stor in th routr s sour tr. Figur () shows s nw sour tr tr prossing th ilur o link (; ); w not tht os not gnrt n upt mssg, us >y ssumption. Suppos link (; ) ils immitly tr th ilur o (; ), no omputs its nw sour tr shown in Figur () without rporting hngs to it us isitsnwsussor tostintions,, n, n <. A prmnnt loop orms mong nos,,n. Figur 2 pits th squn o vnts triggr y th xution o th thir prt o LORA-3 in th sm xmpl introu in Figur, tr th ilurs o links (; ) n (; ). Th igur shows th LSUs gnrt y th no with ill irl trnsmitt in n upt mssg to th nighors, n shows suh LSUs in prnthss. Th thir lmnt in n LSU orrspons to th ost o th link. Unlik in th prvious xmpl, no trnsmits n upt mssg tr prossing th ilur o link (; ) us o th thir prt o LORA-3; th istn rom th nw sussor to n is longr thn rom th prvious sussor. Whn link (; ) ils, no rlizs tht th stintions,, n r unrhl n gnrts n upt mssg rporting th ilur o th link onnting to th h o th sutr o th sour tr tht oms unrhl. Th upt mssg rom triggrs th upt mssgs tht llow nos,, n to rliz tht thr r no pths to,, n. A similr squn o vnts tks pl t th othr si o th ntwork prtition. Th xmpl shown in Figur 3 illustrts th snrio in whih routr tht hooss nw sussor to stintion with lrgr istn to it os not n to sn n upt mssg. For this xmpl, th sour trs o nos,, n r pit in Figurs 2(), (), n 2(), rsptivly. Figur 3() shows th nw sour tr o no tr th ilur o link (; ). In this s, os not n to sn n upt mssg us th prnt no o th sutr h y is nighor o n thror no prmnnt loop n orm. To nsur tht th ov ruls work with inrmntl upts spiying only hngs to sour tr, routr must rmmr th sour tr tht ws lst notii to its nighors. I ny o LORA- to LORA- 3 r stisi, th routr must o on o two things: I th nw sour tr inlus nw nighors thn thos prsnt in th sour tr tht ws lst upt, thn th routr must sn its ntir sour tr in its upt, so tht nw nighors lrn out ll th stintions th routr knows. I th two sour trs imply th sm nighors, th routr sns only th upts n to otin th nw tr rom th ol on. To nsur tht stops sning upt mssgs, simpl rul n us to trmin whih routr must stop using its nighor s rly, suh rul n, or xmpl, th routr with th smllr rss must hng its pth. Th ov ruls r suiint to nsur tht vry routr otins looplss pths to ll known stintions, without th routrs hving to sn upts prioilly. In ition to th ility or routr to tt loops in, th two ky turs tht nl to opt LORA r: () vliting LSUs without th n o prioi upts, n () th ility to ithr listn to nighors pkts or us nighor protool t th link lyr to trmin who th nighors o routr r. I ORA is to support in, th only rul n or sning 5 5 () () (,, ininity) 5 () () Fig.. Routrs running without th thir prt o LORA-3 in t. () () (,, ) (,, ) (,, ) () (,, ininity) () () () (,, ) (,, ) () (,, ininity) Fig. 2. Routrs running with th thir prt o LORA-3 in t. 0 () Fig. 3. Th thir prt o LORA-3 not lwys triggrs th gnrtion o n upt mssg: () ntwork topology, n () th nw sour tr o no tr prossing th ilur o link (; ). upt mssgs onsists o routr sning n upt mssg vry tim its sour tr hngs. III. PERFORMANCE EVALUATION hs th sm ommunition, storg, n tim omplxity thn ALP [5] n iint tl-rivn istn-vtor routing protools propos to t (.g., WRP [5]). Howvr, worst-s prormn is not truly initiv o s prormn. W ompr with, us hs n shown to on o th st-prorming on-mn routing protools [2]. Th protool stk implmnttion in our simultor runs th vry sm o us in rl m wirlss routr n IP (Intrnt Protool) is us s th ntwork protool. Th link lyr implmnts mium ss ontrol (MAC) protool similr to th IEEE 802. [6] stnr n th physil lyr is s () ()

4 4o5 on irt squn spr sptrum rio with link nwith o Mit/s. Th nighor protool is onigur to rport loss o onntivity to nighor i th protion o th link ils in prio o out 0 sons. Th simultion xprimnts us 20 nos orming n -ho ntwork, moving ovr lt sp (5000m x 7000m), n initilly rnomly istriut t nsity o on no pr squr kilomtr. Th simultion stuy ws onut in th C++ Protool Toolkit (CPT) simultor nvironmnt. Th simultion xprimnts us th sm mthoology us rntly to vlut n othr on-mn routing protools [2]. To run in our simultion nvironmnt, w port th ns2 o vill rom [7] into th CPT simultor. Thr r only two irns in our implmnttion with rspt to tht us in [2]: () in th m wirlss routrs n simult protool stk w us thr is no ss to th MAC lyr n nnot rshul pkts lry shul or trnsmission ovr link (howvr, this is th s or ll th protools w simult), n (2) routrs nnot oprt thir ntwork intrs in promisuous mo us th MAC protool oprts ovr multipl hnnls n routr os not know on whih hnnls its nighors r trnsmitting, unlss th pkts r mnt or th routr. Both n n ur 20 pkts tht r witing isovry o rout through th ntwork. Th ovrll gol o th simultion xprimnts ws to msur th ility o th routing protools to rt to hngs in th ntwork topology whil livring t pkts to thir stintions. To msur this ility w ppli to th simult ntwork thr irnt ommunition pttrns orrsponing to 8, 4, n 20 t lows. Th totl worklo in th thr snrios ws th sm n onsist o 32 t pkts/s, in th snrio with 8 lows h ontinuous it rt (CBR) sour gnrt 4 pkts/s, in th snrio with 20 sours h CBR sour gnrt.6 pkts/s, n in th snrio with 4 lows thr wr 7 lows rom istint CBR sours to th sm stintion D gnrting n ggrgt o 28 pkts/s n 7 lows hving D s th CBR sour n th othr 7 sours o t s stintions. In ll th snrios th numr o uniqu stintions ws 8 n th pkt siz ws 64 yts. Th t lows wr strt t tims uniormly istriut twn 20 n 20 sons (w hos to strt th lows tr 20 sons o simult tim to giv som tim to th Link Lyr or trmining th st o nos tht r nighors o th routrs). Th protool vlutions r s on th simultion o 20 wirlss nos in ontinuous motion or 900 n 800 sons o simult tim. Tls I n II summriz th hvior o n oring to th simult tim. Th tls show th totl numr o upt pkts trnsmitt y th nos n th totl numr o t pkts livr to th pplitions or th thr simult worklos. Th totl numr o upt pkts trnsmitt y routrs running vris with th numr o hngs in link onntivity whil gnrts ontrol pkts s on oth vrition o hngs in onntivity n th typ o worklo insrt in th ntwork. Routrs running gnrt lss upt pkts thn in ll simult snrios, th irn inrs signiintly whn t tri ws insrt in th ntwork or 800 sons: routrs running snt rom 00% to 600% mor upt pkts thn whn nos wr moving uring 800 sons o simult tim, n rom 35% to 400% mor upt pkts whn nos wr moving uring 900 sons. Both n wr l to livr out th sm numr o t pkts to th pplitions in th simult snrios with 8 n 4 lows. Whn w inrs th numr o sours o t rom 8 to 20 nos, whil insrting th sm numr o t pkts in th ntwork (32 pkts/s), w osrv tht ws l to livr s muh Numr Upt Pkts Snt Dt Pkts Dlivr Dt Pkts o Flows Gnrt TABLE I AVERAGE PERFORMANCE OF AND FOR NODES MOVING DURING 900 SECONDS OF SIMULATED TIME, TOTAL CHANGES IN LINK CONNECTIVITY WAS 460. Numr Upt Pkts Snt Dt Pkts Dlivr Dt Pkts o Flows Gnrt TABLE II AVERAGE PERFORMANCE OF AND FOR NODES MOVING DURING 800 SECONDS OF SIMULATED TIME, TOTAL CHANGES IN LINK CONNECTIVITY WAS s thr tims mor t pkts thn uring 800 sons o simult tim, n lmost twi th mount o t pkts livr y uring 900 sons o simult tim. Th MAC lyr isrs ll pkts shul or trnsmission to nighor whn th link to th nighor ils, whih ontriuts to th high loss o t pkts sn y nos. In, h pkt hr rris th omplt orr list o routrs through whih th pkt must pss n my upt y nos long th pth towrs th stintion. Th low throughput hiv y or th s o 20 sours o t is u to th poor hoi o sour routs th routrs mk, ling to signiint inrs in th numr o ROUTE ER- ROR pkts gnrt. Dt pkts r lso isr u to lk o routs to th stintions us th ntwork my om tmporrily prtition or us th routing tls hv not onvrg in th highly ynmi topology w simult. Figurs 4() through 4() show th umultiv istriution o pkt ly xprin y t pkts uring 800 sons o simult tim, or worklo o 8, 4, n 20 lows rsptivly. Th highr ly introu y whn rlying t pkts is not irtly Numr Protool Numr o Hops o Flows TABLE III DISTRIBUTION OF DATA PACKETS DELIVERED ACCORDING TO THE NUMBER OF HOPS TRAVERSED (900 SECONDS OF SIMULATED TIME). Numr Protool Numr o Hops o Flows TABLE IV DISTRIBUTION OF DATA PACKETS DELIVERED ACCORDING TO THE NUMBER OF HOPS TRAVERSED (800 SECONDS OF SIMULATED TIME).

5 5o5 % o t pkts ly (ss) () W not tht in ss whr routrs il or th ntwork oms prtition or xtn tim prios th nwith onsum y is muh th sm s in snrios in whih no routr ils, us ll tht must hppn is or upts out th il links to unrhl stintions to propgt ross th ntwork. In ontrst, n svrl othr on-mn routing protools woul ontinu to sn loo-srh mssgs trying to rh th il stintion, whih woul us worst-s nwith utiliztion or. To illustrt th impt th ilur o singl stintion hs in w hv r-run th simultion snrio with 8 lows prsnt in th ntwork or 800 sons mking on o th stintions il tr 900 sons o simult tim, routrs running snt 088 upt pkts whil routrs running snt 3043 upt pkts. Th xistn o singl low o t to stintion tht ws unrhl or 900 sons m to gnrt 55% mor upt pkts whil gnrt out th sm numr o upts (s Tl II). % o t pkts % o t pkts ly (ss) () ly (ss) () Fig. 4. Cumultiv istriution o pkt ly xprin y t pkts uring 800 sons o simult tim or worklo o () 8 lows, () 4 lows, n () 20 lows. rlt with th numr o hops trvrs y th pkts (s shown in Tls III n IV) ut with th poor hoi o sour routs whn th numr o lows inrs rom 8 to 20. In ll th simultion snrios th numr o stintions ws st to just 40% o th numr o nos in th ntwork in orr to ir with. For th ss in whih ll th nos in th ntwork riv t, woul introu no xtr ovrh whil oul svrly pnliz. It is lso importnt to not th low rtio o upt mssgs gnrt y ompr to th numr o hngs in link onntivity (Tls I n II). IV. CONCLUSIONS W hv prsnt, link-stt protool tht inurs lss ovrh thn on-mn routing protools. Bus n us with ny lustring mhnism propos to t, ths rsults lrly init tht is vry ttrtiv pproh or routing in pktrio ntworks. Prhps mor importntly, th pproh w hv introu in or lst-ovrh routing opns up mny rsrh vnus, suh s vloping similr protools s on istn vtors n trmining how rout ggrgtion works unr LORA. REFERENCES [] D. Brtsks n R. Gllgr, Dt Ntworks, Son Eition, Prnti-Hll, In., 992. [2] J. Broh t l, A Prormn Comprison o Multi-Hop Wirlss A Ho Ntwork Routing Protools, Pro. ACM MOBICOM 98, Dlls, TX, Otor 998. [3] J.J. Gri-Lun-Avs n J. Bhrns, Distriut, sll routing s on vtors o link stts, IEEE Journl on Sl. Ars in Commun., Vol. 3, No. 8, 995. [4] J.J. Gri-Lun-Avs t l., Wirlss Intrnt Gtwys (WINGS), Pro. IEEE MILCOM 97, Montry, Cliorni, Novmr 997. [5] J.J. Gri-Lun-Avs n M. Spohn, Sll Link-Stt Intrnt Routing, Pro. IEEE Intrntionl Conrn on Ntwork Protools (ICNP 98), Austin, Txs, Otor 4-6, 998. [6] P802. Unpprov Drt: Wirlss LAN Mium Ass Control (MAC) n Physil Spiitions, IEEE, Jnury 996. [7] D. Johnson n D. Mltz, Protools or Aptiv Wirlss n Moil Ntworking, IEEE Prs. Commun., Vol. 3, No., Frury 996. [8] J. Juin n J. Tornow, Th DARPA Pkt Rio Ntwork Protools, Proings o th IEEE, Vol. 75, No., Jnury 987. [9] V.O.K. Li n R. Chng, Propos routing lgorithms or th US Army moil susrir quipmnt (MSE) ntwork, Pro. IEEE MILCOM 86, Montry, Cliorni, Otor 986. [0] J. Moy, OSPF Vrsion 2, RFC 583, Ntwork Working Group, Mrh 994. [] V. Prk n M. Corson, A Highly Aptiv Distriut Routing Algorithm or Moil Wirlss Ntworks, Pro. IEEE INFOCOM 97, Ko, Jpn, April 997. [2] C. Prkins n P. Bhgwt, Highly Dynmi Dstintion-Squn Distn- Vtor Routing (DSDV) or Moil Computrs, Pro. ACM SIGCOMM 94, Lonon, UK, Otor 994. [3] C. Prkins, A-Ho On Dmn Distn Vtor (AODV) Routing, rt-itmnt-ov-00.txt, Novmr 997. [4] R. Rmnthn n M. Stnstrup, Hirrhilly-orgniz, Multihop Moil Wirlss Ntworks or Qulity-o-Srvi Support, ACM Moil Ntworks n Applitions, Vol.3, No., pp. 0-9, 998. [5] S. Murthy n J.J. Gri-Lun-Avs, An Eiint Routing Protool or Wirlss Ntworks, ACM Moil Ntworks n Applitions Journl,Spil issu on Routing in Moil Communition Ntworks, 996. [6] M. Stnstrup (E.), Routing in Communition Ntworks, Prnti-Hll, 995. [7] Th CMU Monrh Projt, Wirlss n Moility Extnsions to ns-2 - Snpshot.0.0-t, URL: August 998.