A Priority Queuing Model for HCF Controlled Channel Access (HCCA) in Wireless LANs

Transcription

1 . J. Coucatos, Ntwor ad st ccs, 9,, -89 ublshd l Fbruar 9 crs rort uug Modl for CF Cotrolld Chal ccss CC Wrlss LNs Rza GZZE, gzh FN, Y N Klab of forato Codg ad rassso, sttut of Mobl Coucatos, outhwst Jaotog Urst, Chgdu, Cha partt of Coputr cc, Gorga tat Urst, tlata, G, U Eals: r_ghazzadh@ahoo.co, p.fa@.org, pa@cs.gsu.du Rcd Ju 5, 8; rsd cbr, 8; accptd cbr 3, 8 bstract Rctl, thr has b a rapd growg trst w applcatos rqurg qualt of src o guarats through wrlss local ara twors WLN. hs dads ha ld to th troducto of w 8. stadard srs to hac accss du supportg o for ultda applcatos. owr, so applcatos such as arabl bt rat R traffc addrss so challgs th hbrd coordato fucto CF oatd to prod o. hs papr prsts a ol prort quug odl to aalz a du accss th CF cotrolld chal accss CC od. hs odl as us of a M Maroa rral rocss/ has p/ quu wth two tps of obs whch ar sutabl to support R traffc. Usg a M for traffc arral procss ad dstrbuto for src procss, th cluso of acato prod as our aalss r gral ad coprhs to support arous tps of practcal traffc stras. h proposd prort quug odl s r usful to aluat ad hac th prforac of th schdulr ad th adsso cotrollr th CC chas. Kwords: o, CC, rort uus, Matr-Gotrc Mthod, M//. troducto crasg dads to accss to twor hotspots aras at arports, hotls, coff shops ha ld wrlss local ara twor WLN to b a tcholog for hgh-spd local accss publc ad prat aras. Furthror, th ar futur, WLN wll pla a rol wth th hbrd wrlss ssts ad also t s th bst caddat to coct ho dcs to wrlss twors. hrfor, t should b abl to allow usrs to ubqutousl accss a larg art of srcs. th othr had, dads for w applcatos such as ral t traffc, ultda do ad oc or ar crasg rapdl. hs applcatos ha cratd d for o support. owr, EEE8. s usutabl for ultda applcatos to support o th MC lar. hrfor, EEE8. worg group has b dlopg a w protocol, EEE8., whch wll b abl to prod o faturs. EEE8. troducs th hbrd coordato fucto coprsd of two du accss chass: cotto-basd chal accss rfrrd to as hacd dstrbutd chal accss EC ad cotrolld chal accss rfrrd to as CF cotrolld chal accss CC. lthough cotto-basd chal accss s r spl ad robust for bst ffort traffc, t ca ot prod o guarats asl. hs ca b achd wth th pollg-basd du accss through th CC. h CC prods a hbrd coordator C wth ablt to assg a cotto fr t tral durg cotto prod ad cotto fr prod to pact trassso. hrfor, trassso opportut X ad src tral ar r portat paratrs to prod o guarats. rfrc schdulr calculats ths paratrs wth th rsrato forato achd through th gotato wth th d usrs. Usg arag alus, such as arag pact lgth ad arag data rat, to coput trassso paratrs caus so challgs to o support R traffc. hrfor, odfcato of th schdulr to prod such traffc s r crucal. ths wa, aaltcal sst aalss s r usful to pro ad dlop th sst. Coprght 9 crs.. J. Coucatos, Ntwor ad st ccs, 9,, -89

2 RRY UEUNG MEL FR CF CNRLLE CNNEL CCE CC 3 N WRELE LN hs papr prsts a prort quug odl to aalz a du accss th CC. ccordg to th CC charactrstcs, th odl s basd o a M/ / quu wth acato ad t-ltd src th prsc of two prort lls. o portat prforac asurs ar prstd aftr solg th quug odl through th atr-aaltc thod,3. o our bst owldg, although thr ar so paprs whch ha stgatd th CC ad th EC through sulato 4-9, ad th EC aaltcall -, thr s ol o publshd aaltcal wor for th CC 3, whr a quug odl wthout prort lls has b dlopd. owr, prort s a pot to sparat arous traffc stras wth dffrt o rqurts, spcall for ral-t ad o-ralt traffc. addto, to aag rsourcs, us badwdth ffctl ad prod o for arous traffc stras, t s cssar that dffrt traffc stras appar th dffrt statstc or dac prort lls th sst. hrfor, EEE8. troducs four prort lls for ght groups of traffc stras. Cosqutl, to odf ad stgat th prforac of th schdulr ad th adsso cotrollr, prort aaltcal odl th prsc of prortzd traffc s r hlpful. 4, a prort odl a du wthout a acato prod ad t-ltd src was troducd. hat odl ca ot b appld to th CC du accss whch s basd o a acato prod ad t-ltd src. hs papr wll prst a prort quug odl to aalz du accss th CC b ag us of a M// quu wth two tps of obs whch ar sutabl to support ast practcal traffc stras. h rst of th papr s orgazd as follows: cto, w brfl dscrb th CC chas, phas tp dstrbuto ad dscrt Maroa arral procss M; our proposd odl s prstd cto 3; th rlatd prforac asurs ar aalzd cto 4; urcal ad sulato rsults ar g cto 5; ad fall coclusos ar draw cto 6.. CC ad st aratrs.. CC EEE8./CC s a pollg-basd du ad ctralzd schdulg whch s cotrolld b th C. Each stato that rqurs a strct o support s allowd to sd o rqurt pacts to th C ad th C assg a corrspodg trassso opportut to th stato. h C ca start a pollg prod at a t durg a cotto prod aftr th du ras dl for at last pot coordato fucto CF tr-fra spac tral. Each stato ca trast a squcs of data pacts sparatd b a short tr-fra spac durg ow X allocatd b th C a cotto fr prod. hrfor, as t has show Fgur, a squc of trassso opportuts wll b assgd to th statos durg ach. Cosqutl, ach stato s polld oc pr ad allowd to trast ts pacts utl ts X durato lapss. Upl ad dowl Xs ar tatd b th schdulr th C ad d wh thr s o pact th quus for trassso or X durato prs. o prod o, ach stato aags o cotrol fld addd to th lgac fras. Cosqutl, th schdulr rcs sparatd rsrato forato of dffrt traffc stras to calculat a aggrgatd src schdul. o of ths forato s th a data rat, dla boud, au burst sz, u phscal rat, usr prort ad pa data rat. h schdulr, frst of all calculats th au src tral accordg to th dla boud for ach traffc stra. h, t slcts th sallst src tral aog all th au src trals corrspodg wth th traffc stras as a src tral for all statos. h schdulr aftr that dtrs X for ach traffc stra accordg to th gotatd rsrato forato. llocatd X for ach stato s su of all Xs of stato s traffc stras. X of th stato that has ad traffc stras s coputd as follows. X a ρ L R L M o, R o whr R dots th u phscal data rat, L ad M rprsts th oal ad th au sz of pact rspctl, ρ dots th a data rat ad rprsts th orhad du to th phscal ad MC hadrs, acowldgt ad pollg fras. ccordg to th src tral durato, th ubr of act statos ad th X durato ach stato, a adsso cotrollr aags th ubr of act statos to prod o... scrt Maroa rral rocss M Cosdr a dscrt t Maro cha wth a trasto atr ad two sub-stochastc atr,, whr. uppos at th t t, th Maro cha s th stat,. h, at th t poch t wth probablt,, arral procss trs stat, ad starts a batch of arrals. hrfor, corrspods to a trasto atr wth o arral ad corrspods to a trasto atr wth ol o arral pr t slot. X X X Fgur. X allocato cotto fr prod. X X X Coprght 9 crs.. J. Coucatos, Ntwor ad st ccs, 9,, -89

3 3 R. GZZE E L..3. has p strbuto has tp dstrbutos ca approat a of gral dstrbutos coutrd quug ssts. hrfor, t s approprat src t odlg. Cosdr a stats Maro cha wth o absorbg stat, ad tal probablt ctor, wth lts whr s a row ctor wth lt whl s colu ctor of o. Lt th trasto probablt atr of th Maro cha b :. whr s a sub-stochastc trasto atr, - s osgular s dtt atr ad. h absorbg Maro cha ca talz fro a stats accordg to th tal ctor ad gts absorbd to th absorbg stat. hrfor, th t to absorpto such a Maro cha s sad to ha phas tp dstrbuto whch s rprstd wth th par,. 3. roposd rort uug Modl o clarf th odl, suppos that thr s o stato coucatg wth th C th sst. h C ca b cosdrd as a sgl srr whch srs quus hgh ad low prort of th stato o or tha slots au X durato s ddd to slots durg ach. th w of th stato, as soo as t slots s usd up or quus bco pt, th srr gos o a acato.. th srr srs othr statos or bcos dl utl th t st. c, as t s llustratd Fgur, th u acato durato s subtracto of th ad th au X durato. t s assud that th C s a srr whch srs prort quus o-prpt prort cas durg a X prod. a o-prpt cas, o src trrupto s appld upo arral of a hgh prort pact wh a low prort pact s bg srd. o aalz th dscrt t Maro cha MC dscrbg th quug odl, arral procss, src procss ad acato odl ar dfd. h arral procss s odld b a dscrt Maroa arral procss M to allow corrlato aog th tr-arral ts wth pacts wth ach prort ad btw two prorts pacts ad support arous tps of traffc stras, spcall R traffc whch grat pacts rado arral trals. th othr X rc rod acato rod X Fgur. rc ad acato prods for o stato CC. had, t s obous that th pact trassso t s corrspodg to th src t whch dpds o th pact lgth whl th chal data rat s fd. hrfor, to support arous pact lgth dstrbutos ad a th odl of src procss or gral ad coprhs, a phas tp dstrbuto s proposd for a src procss odl. Cosqutl, th troducd prort quug odl s basd o a M/ / quu wth acato ad t-ltd src. h proposd odl s basd o th wor of 4 whch as us of atr-gotrc soluto for aalss prort quus wthout acato ad t ltato src. o of th otatos ad sbols whch wll b usd throughout th papr ar troducd as follows: s a colu ctor of o wth approprat ordr quals to th ubr of colus of th atr or to th ctor lgth that t s ultpld wth, rprsts a colu ctor of zros wth lgth cpt at th th posto that s o, s th traspos of ctor, dots a dtt atr of dso ad rprsts. 3.. rral rocss h arral procss s odld b a dscrt Maroa arral procss M. h M, a tso of th Maro odulatd roull procss, ca support a tps of traffc flows such as R traffc gratg arabl pacts lgth arabl tr-arral prods. uppos thr ar two dpdt tps of traffc corrspodg to two prorts whr ach traffc sourc s abl to grat ol o pact pr t slot. c, ach traffc flow wll ha two sub-stochastc atrcs cto. ad cosqutl thr ar four substochastc atrs,,, corrspodg to o pact arral hgh prort ad low prort pact arral whr dots a trasto atr wth o pact arral, s a trasto atr wh o hgh prort pact arrs, rprsts a trasto atr wh o low prort pact arrs, s a trasto atr wh two hgh ad low prort pact arro of ach prort pact ad also whr rprsts stochastc atr. h arral rat s ψ, whr ψ ψ ad ψ s a colu ctor of o. s tod abo, four sub-stochastc atrcs ca b prssd b th sub-stochastc atrcs of both traffc stras. uppos ad ar th trasto atrcs th hgh prort traffc wh o pact ad o pact arrs at a t slot, rspctl. Furthror assu, ad ar th trasto atrcs th low prort traffc wh o pact ad o pact arrs at th t slot rspctl. Coprght 9 crs.. J. Coucatos, Ntwor ad st ccs, 9,, -89

4 RRY UEUNG MEL FR CF CNRLLE CNNEL CCE CC 33 N WRELE LN ths cas,,, ad, whr s th Krocr product. 3.. rc rocss h src procss s corrspodg to th trassso t. h total trassso t of a fra s su of trassso t of data pact, ts cssar hadrs addd b th MC ad phscal lar, CK, ad short tr-fra spac F. W assu that th chal data rat, CK, F duratos ad hadr sz ar fd. c, th src t of a pact ca b cosdrd as a rado arabl whch ars ol wth th lgth of th pact. Cosqutl, to gralz th odl ad support dffrt pact lgth dstrbutos, w cosdr phas tp dstrbuto for both hgh prort ad low prort src procsss. Lt, ad, dot dstrbuto for hgh prort ad low prort srcs, rspctl whr, ar trasto atrcs of dsos,, rspctl ad, rprst tal ctors., ar trasto to absorpto ctors for th hgh prort ad low prort srcs, rspctl acato Modl th src prod, whr thr s o pact th quus or th X durato prs, th srr trs a acato prod. hrfor, th acato durato dpds o th src durato. acato wth th au durato bgs whr th srr sts th stato at th frst slot of X ad th stato has o pact to trast. Cosqutl, a acato odl ca b rprstd b a, phas tp dstrbuto whl th Maro cha ca talz fro a stats dpdg o th acato durato. hrfor, th tal ctor, th trasto atr ad th trasto to absorpto ctor wll b, ad, rspctl tat pac ad rasto Matr of th MC ths subscto, w troduc stat spac ad th trasto atr of th dscrt t Maro cha MC. h stat spac ca b ddd to two a groups that ar acato ad src stat spacs. Each of ths stats ar dscrbd b th ubr of th pacts th hgh prort ad low prort quus,, th phas of th arral procss, th phas of th hgh prort or low prort src procsss,, th phas of th acato l ad th phas of th X t. hrfor, th stats ca b prssd as follows. d,,, l, ; ;,,..., ; l,..., r} d s,,,, t, ;,,..., ; t,..., ;,,..., } d s,,,, t, ; ;,,..., ; t,..., ;,,..., } d s,,,, t, ; ;,,..., ; t,..., ;,,..., } whr s th buffr sz th ubr of pacts hgh prort ad low prort, d dots th acato stats whl th ubr of hgh prort ad low prort pacts th quus ar ad rspctl ad th pact arral s th phas as wll as acato s l s th phas, d rprsts src stat spac wh thr ar ol low prort pacts th sst. hrfor, a low prort pact s bg srd whl th src s th phas K at t th t slot ad th pact arral s s th phas as wll. th sa wa, d s src stat spac wh thr s at last o hgh prort pact th sst ad a low prort pact s bg srd, ad s d rprsts src stat spac wh thr s at last o hgh prort pact th sst ad a hgh prort pact s bg srd. h trasto atr of th dscrt t Maro cha ca b prssd as follows. probablt acato to acato fro toacato of rag probablt of swtchg fro low prort src probabltof swtchg hgh prortsrc probablt of swtchg fro acato to low prortsrc probabltof rag low prortsrc probabltof swtchg fro hgh prortsrc to low prortsrc probabltof swtchg fro acato to hgh prort src probabltof swtchg fro low prort src to hgh prort src probablt of rag hgh prort src Fgur 3. Gral for of th trasto probablt sub atr. Coprght 9 crs.. J. Coucatos, Ntwor ad st ccs, 9,, -89

5 34 R. GZZE E L. whr th rows of atr corrspod to th ubr of pacts th hgh prort quu. hrfor, atr wll ha rows. s t s assud that ach tp of traffc ca grat ol o pact ad ol o pact ca b srd pr t slot lss tha or qual to o, th structur of atr s quas-brth-dath. Cosqutl, th lts of atr rprst bloc trasto atrcs whch th ubr of pacts th hgh prort quu crass, or dcrass, b o, or ras arat, aftr trasto at th currt t slot. th othr had, ach lt of atr also rprsts o atr dscrbg low prort quu sz. hrfor, ach row of,,, 3,, bloc atrcs, dscrbd as follows, rprsts th ubr of low prort pacts th quu. o dscrb ach sub atr wth gral for b a b or a, a gral sub atr for s dfd Fgur 3. h gral sub atr ca b udrstood as th trastos probablt atr gorg swtch aog a acato, a hgh prort ad a low prort src. Not that th au src durato s slots ad trasto ca happ at a t slots. hrfor, src prod th gral atr s ddd to slot hgh prort ad low prort. t s obous that so of th stat trastos th gral atr a ot happ. hrfor, thos stats wll b zro. o rducto of th atr dsos, thos rows ad colus of th gral atr whch ar zro wll b rod f th gral atr ca atch wth th othr atrcs th atr. Now, th rst of ths sub scto, w prss th sub atrcs b cosdrg th possbl stat trastos th gral atr for. loc atr rprsts stat trastos wh hgh prort ad low prort quus ar pt ad ra pt aftr trasto. rastos occur whr o pact arrs ad th srr s o acato, or coplts acato ad starts t aga. s thr s o pact to b srd, th au acato durato wll b talzd. 4 5 atr dots trastos whch th ubr of pacts th low prort quu crass b o whl th both quus ar pt. rastos occur whr ol a low prort pact arrs ad th srr stas o acato or coplts acato ad starts th low prort src at th frst slot of th X. 6 t s assud that whr th both quus bco pt th srr gos o acato. h acato ca bg fro dffrt stats of ts Maro cha whch s dpdt o th stat that th quus bco pt th src prod. supports stat trastos that o pact arrs, th procss of th last low prort pact s copltd. Cosqutl, quu bco pt ad th acato prod bgs trastos ca happ at a t slots th X prod,..,.,, M bloc atrcs rprst trastos whch th ubr of pacts th low prort quu ras arat, crass, dcrass b o rspctl whl th hgh prort quu ras pt aftr trasto, ad thr s at last o pact th low prort quu bfor trasto. hs codtos ca happ o th acato, or th src low prort quu s srd. Now, w pla possbl stat trastos th bloc atr 7. W dd trastos to two cass. o pact arrs, ad a th srr ras o acato, b th srr ds acato ad gos o th low prort src at th frst slot of X... c th srr ras o th procssg of low prort pact, d th srr las th src procssg du to th X prato ad trs acato. a low prort pact arrs, ad a th procssg of a low prort pact s copltd ad a w low prort procssg bgs, b th procssg of a low prort pact s copltd whl th X durato prs as wll ad th srr gos o acato L L 8 Coprght 9 crs.. J. Coucatos, Ntwor ad st ccs, 9,, -89

6 RRY UEUNG MEL FR CF CNRLLE CNNEL CCE CC 35 N WRELE LN cotas th stat trastos crasg th ubr of pacts th low prort quu b o ad rag th hgh prort quu pt whl thr s at last o pact th low prort quu bfor trasto. ca asl coput th possbl trastos such abo dscussos 9 rprsts stat trastos whch th ubr of pacts th low prort quu dcrass b o ad at last o pact s th low prort quu bfor trasto as wll as hgh prort quu ras pt. hs trastos happ wh o pact arrs ad th procssg of a low prort pact s copltd, ad a th procssg of aothr o bgs, b th X durato prs ad a acato prod bgs.,,,, ad thr lts ca b coputd th sa ar. h bloc atrcs ar g ppd. 4. rforac Masurs ccordg to th structur of atr, ts stad stat dstrbuto ctor ca b obtad b applg th atr-gotrc thod. Lt probablt stad stat dstrbuto ctor b whr, ad,,, whr s th probablt that th ubr of pacts th hgh prort ad th low prort quus ar ad rspctl whl tp pact : hgh prort, : low prort s bg srd at th th t slot of th X prod. Usg balacd quatos, ad th atr-gotrc thod, th stad stat ctor ca b calculatd. For or dtals of how to fd out stad stat ctor, radrs ca rfr to. 4.. uu Lgth strbuto Lt f h l f l l b th probablt that thr ar l hgh prort pacts low prort pacts th quu. h lgth of th hgh prort quu wll b l f thr ar l hgh prort pacts th sst ad th srr s ot o th procssg of th hgh prort pact.. s o acato or th procssg of th low prort pact or, l hgh prort pact ar th sst whl o hgh prort pact s bg srd. l fh L l l l l l fl L l l l l l l robablt of th quu lgth at th d of th X durato ca b calculatd th slar ar. 4.. act Loss Rat act loss occurs whr a w pact arrs ad th targt buffr s full. hs codtos ca happ durg src procssg at a t slots of th X durato or acato. h hgh prort pact wll b lost wh th ubr of pacts th hgh prort quu s rgardlss of th ubr of pacts th low prort quu ad a w hgh prort pact arrs b tslf or togthr wth a low prort pact. hrfor, th pact loss probablt wll b su of all possbl probablts aog acato ad src prod satsfg abo codtos. s a apl, shows su of th probablts whch th srr stas o th hgh prort procssg whl a w hgh prort pact arrs ad th othr tod codtos has b satsfd. Cosqutl th hgh prort act loss rat whch s oralzd wth th hgh prort arral rat s prssd as follow. Lh 3 Coprght 9 crs.. J. Coucatos, Ntwor ad st ccs, 9,, -89

7 36 R. GZZE E L. t th sa wa, act loss th low prort quu occurs wh th low prort quu s full ad a w low prort pact arrs. hrfor all possbl stats satsfg thos codtos could b prssd as follows. b 4.3. ccss la strbuto 4 ths subscto, w troduc accss dla dstrbuto for th hgh prort ad th low prort pacts. ccss dla s th rqurd t whch a arrg pact at th targt quu rachs th had of quu. ccss dla ca b studd as a absorbg Maro cha. h cha talzs wh th pact arrs th quu, ad gts absorbd wh th pact rachs th had of th quu. hrfor, th accss dla s th rqurd t to absorpto th Maro cha. th hgh prort quu, prcd dla s th prod of th t whch a arrg pact has to wat utl all hgh prort pacts ahad of t ar srd, ad th procss of a low prort pact, whch s bg procssd at th arral t, s copltd hrfor, th accss dla th hgh prort quu dpds o th ubr of th hgh prort pacts ahad of a arrg pact. uppos z dfs th tal probablt ctor th hgh prort accss dla. z z z... z z z z... z z... z 5 L L whr z, zl ad z dot th probablt of th arrg hgh prort pact fdg hgh prort pact ahad of t wth th srr: acato, th low prort procssg at th th slot of th X ad, th hgh prort procssg at th th slot of th X, rspctl. robablt ctor z rprsts th probablt of arrg hgh prort pact rgardlss of low prort pact arral, fdg o hgh prort pact ahad of t wth srr: o acato. h possbl scaros ar a thr s o pact th hgh prort quu ad th srr stas o acato,, b th srr coplts th procssg of th last hgh prort pact th th slot th last slot of X ad gos o acato, c th srr las th low prort procssg du to th X prato ad gos o acato, d th srr coplts th low prort procssg at th th slot ad gos o acato. Cosqutl, z whch s oralzd b ca b prssd as follows. z 6 z L rprsts th probablt ctor whch arrg hgh prort pact fdg o hgh prort pact ahad of t whl srr s srg a low prort pact at th th slot of th X. t ca occur wh th srr stas o th procssg of a low prort pact at th th slot of th X whl hgh prort pact arrs. zl 7 h othr lts whch ar g ppd ca b calculatd usg slar abo dscussos Now, to fd th t tll absorpto a Maro cha, th trasto atr for hgh prort pact accss dla h s rqurd. hs atr s dfd as follows. h 8 t s obous that th accss dla for a arrg hgh prort pact ol dpds o th ubr of hgh prort pacts ahad of th arrg pact. h ubr of pacts whch arrs aftr dsrd pact has o ffct o th accss dla. hrfor, th arral trasto atr wll b. Now, ach lt of h atr ca b coputd wth th slar dscussos th cto 3.4. For apl, rprst stat trastos wh th ubr of pacts ahad of arrg pact chags fro to at th d of trasto. t s obous that trastos occur wh th hgh prort procssg s copltd. 9 Coprght 9 crs.. J. Coucatos, Ntwor ad st ccs, 9,, -89

8 RRY UEUNG MEL FR CF CNRLLE CNNEL CCE CC 37 N WRELE LN h othr lts ar g ppd. Fall, th probablt ctor aftr lapsg t slot wll b z z h whr z z. o rducto of coputato, th st of followg quato ca b usd. z z z z z z Fall, lt W b th probablt that th watg t of hgh prort pact s lss tha or qual to, th z W h whr z s th probablt ctor that th arrd hgh prort pact fdg o pact a had of t aftr slot. h low prort accss dla s calculatd ppd C. 5. Nurcal ad ulato Rsults ths scto, frst w prod a spl apl of wrlss ultda coucatos to dostrat how ca appl th coputatoal algorth. t s assud that th wrlss twor ca trast a fd sz data bloc durg o t slot, ad ach pact s sgtd to a ubr of data blocs. uppos a stato ca trast oc ad do traffc. Furthror, th prort of oc traffc s hghr tha th do traffc. oc traffc s odld b a N/FF sourc as dpctd Fgur 4a. hrfor, ad ca b calculatd as follows 5. R*, R * γ µ γ µ R whr s th probablt of th pact arral pr t slot. Now assu that th oc pact lgth s fd ad s thr ts or tha data bloc sz. hrfor, µ µ µ γ FF 3µ γ FF γ a N µ µ 3 3γ Fgur 4. N/FF traffc odl for oc ad R traffc. γ 3γ b 3 3 h R traffc s odld b thr dpdt N/FF sourcs as showd Fgur 4b., ad ca b asl calculatd l oc traffc atrcs. Radrs to fd or dtals ca rfr to 5. f w assu that th au do pacts sz s 8 ts or tha data bloc sz, ad do pacts sz follow log-oral dstrbuto wth a probablt ass fucto p trs of th ubr of data blocs such a followg apl 3 p h, ad wll b Lt ad X duratos b ad slots, rspctl. h,, Usg th abo forato, o ca asl fd out sst prforac through th troducd odl. Now, accordg to th 8. ad charactrstcs of th appld traffc stras whch ar dscrbd as follow, th urcal rsults obtad fro th aaltcal odl ar copard wth sulato rsults. W aalz th quu lgth ad th accss dla dstrbuto as wll as th pact loss rat for th hgh prort ad th low prort pacts. lar to abo apl, o ca asl atch th proposd odl wth th troducd traffc ad sst paratrs. t s assud that th oc traffc s hadld wth a hghr prort tha do traffc. h oc traffc s odld b a N/FF sourc whch grats 6 octt ssag prodcall wth a bt rat 64 b/s durg act prod. h CR do traffc has ol a N stat ad alwas stas that. h R traffc s odld b thr dpdt N/FF sourcs wth th a bt rat Kb/s. howr, th hft progra 6 ca b usd to fd out th phas tp dstrbuto of src ts of ral traffc. abl suarzs th dffrt traffc usd for th aaltcal aalss ad sulatos. t s assud that th quu buffr sz s s ad th chal data rat s Mbps. ulatos ar prford usg progra whch s wrtt C du. hr ar two quus ach stato, ad th srr procsss pacts ach of th quus th FF fasho. hr ar t statos whch ar coucatg wth th accss pot. ll statos o N/FF oc traffc as hgh prort traffc. F Coprght 9 crs.. J. Coucatos, Ntwor ad st ccs, 9,, -89

9 38 R. GZZE E L. statos grat th CR do traffc ad th othrs sd th R do traffc as low prort traffc. rrals to th quus ar dpdt of whthr th srr s src or o acato. h Xs durato ar calculatd through Eq, accordg to th traffc forato ach stato. Each stato ca trast ts data durg ts X prod. Fgur 5 shows cuulat dstrbuto fucto CF of th hgh prort ad th low prort quu lgth for R, CR do ad oc traffc stras. lthough th CR pact arral rat s uch largr tha that of th R traffc stra, th quu lgth th CR traffc s lss tha that o th R traffc cosdrabl. s t s obous fro th tod fgur, th probablt that th lgth of th quu gt lss tha or qual to s s about 98 prct for th CR traffc whl that s about 74 prct for th R traffc. t as that ost of th t th R pacts ra th quu ad uabl to b trasttd. hrfor, th pact loss gos up ad lots of pacts drop. ulato ad urcal rsults show that th pact loss rat s about 8 prct for th R traffc whl t s about.6 prct for th CR do traffc. Cosqutl, although thr s ough badwdth to support o guarat th R do traffc but th schdulr s uabl to us t. h CF of th quu lgth at th d of th X for all traffc, plottd Fgur 6, cofrs cratd challgs through th R traffc. hrfor, th odfcato of th schdulg algorth ad troducto of a dac schdulr to adapt wth th burst arrals ar uaodabl. ac codtos th schdulr ca b obtad through adustg th X ad th duratos basd o th pact quu lgth statstcs. chdulr ca gt th forato fro th statos ad fd th optal X ad through th plog th odl to ata a pt quu at th d of X durato. Fgur 7 shows CF of th accss dla ad pact blocg th hgh prort ad th low prort traffc through aalss ad sulatos. t s obsrd that all pacts th CR do traffc prc accss dla lss tha about 35 s, whl ol 3 prct of th R do pacts prc such a cuulat accss dla. lthough thr s ough badwdth to srg th R traffc, th schdulr dos ot ha sstal flblt to support of burst arral rat. Cosqutl, th quu wll b full ad 8 prct of arrd pacts ar blocd ad droppd. Fall, fro Fgurs 5-7, t ca b radl s that th aldato of aaltcal odl s cofrd b th urcal rsults obtad fro aaltcal odl ad th sulato rsults udr th sa codtos. abl. scrpto of dffrt traffc stras. pplcato rral ratkb/s act szbt oc 64 6 R do 66 CR do 3 9 CF oc. oc a. R do. R do a. CR do. CR do a Nubr of pacts th quu Fgur 5. CF of pact quu lgth for dffrt traffc stras ulato. & altcal a.. CF oc s. oc a. R do. R do a. CR do. CR do a act quu lgth at th d of X Fgur 6. CF of pact quu lgth for dffrt traffc stras at th d of X ulato. & altcal a.. CF oc. oc a. R do. R do a. CR do. CR do a la sc Fgur 7. CF of accss dla for dffrt traffc stras ulato. & altcal a.. 6. Coclusos h schdulg algorth whch s troducd b CC /EEE8. to support o ultda applcatos os sparatd quus wth spcfd prort lls ad trassso opportut accordg to th traffc stras charactrstcs. h trassso opportut s foud out basd o th a alus. hrfor, so ultda traffc stras such as R traffc addrss Coprght 9 crs.. J. Coucatos, Ntwor ad st ccs, 9,, -89

10 RRY UEUNG MEL FR CF CNRLLE CNNEL CCE CC 39 N WRELE LN so challgs ths du. Cosqutl, adaptg algorths to w codtos ordr to prod dsrd o s o th focus of rsarchrs. o stgat ad pro th schdulr, aaltcal odl s r usful. hs papr troducd a prort quug odl for th CC. Usg of th M// quu as th odl or coprhs ad prods t to support dffrt practcal traffc stras. h portat prforac asurs th hgh prort ad th low prort quus ar calculatd whch abl us to stgat th ffct of th ad th X duratos o o guarats ad fd out th optal X alus accordg to th quu lgth ad th accss dla statstcs to prod o. t s show b th urcal ad th sulato rsults that th aaltcal odl s qut accurat, ad thus usful th practcal sst dsg ad prforac aluato. 7. cowldgts hs wor was supportd part b th Natoal cc Foudato of Cha NFC udr th Grat No , th roct udr th grat No.--4, th Natoal 863 gh-ch R& rogra udr th grat No.7Z8. 8. Rfrcs EEE 8./3., art, Wrlss LN du accss cotrol MC ad phscal lar Y spcfcatos: Mdu accss cotrol MC hacts for qualt of src o, draft supplt to EEE 8. td, Jauar 5. M. F. Nuts, Matr gotrc solutos stochastc odls-a algorthc approach, Joh ops Urst rss altor, M, J.. Zhao,. L, X. Cao, ad. had, Matr-aaltc soluto for M// prort quu, uug sts Joural, prgr Nthrlads, ol. 53, No. 3, pp Jul Magold,. Cho, G. R. rtz,. Kl, ad. Wal, alss of EEE 8. for o support wrlss LNs, EEE Wrlss Coucatos, pp. 4-5, cbr sl,. N, ad. urltt, FCF: pl ad a ffct schdulg sch for EEE 8. wrlss LN, Mobl Ntwors ad pplcatos, No., pp , prl Grlo, M. Macdo ad M. Nus, chdulg lgorth for o upport EEE8. Ntwors, EEE Wrlss Coucatos, pp , Ju lra,. Molaro, G. Ruggr, ad. rpod, prog o ad throughput sgl ad ulthop WLNs through dac traffc prortzato, EEE Ntwor, pp , Ju 5. 8 N. ada,. ugar,. Gupta, ad. ahl, strbutd far schdulg a wrlss LN, EEE rasactos o Mobl Coputg, ol. 4, No. 6, pp , Nobr Zha, X. Ch ad Y. Fag, ow wll ca th EEE 8. wrlss LN support qualt of src? EEE rasactos o Wrlss Coucatos, ol. 4, No. 6, pp , Nobr 5. Z. Kog,. sag ad. saou, rforac aalss of EEE8. cotto-basd chal accss, EEE Joural o lctd ras Coucatos, ol., No., pp. 95-6, cbr 4. Y. Xao, rforac aalss of prort schs for EEE 8. ad EEE 8. wrlss LNs, EEE rasactos o Wrlss Coucatos, ol. 4, No. 4, pp , Jul 5.. Zhu ad. Chlatac, rforac aalss for EEE 8. ECF src dffrtato, EEE rasactos o Wrlss Coucatos, ol. 4, No.4, pp , Jul 5. 3 M. M. Rashd ad E. ossa, uug aalss of 8. CC wth arabl bt rat traffc, EEE tratoal Cofrc o Coucatos, ol., pp , lfa, Matr gotrc soluto of dscrt t M// prort quu, Naal Rsarch Logstcs, ol. 45, pp. 3-5, Jul C. loda ad. Casals, rforac aalss of statstcal ultplcato of R sourcs, Cofrc of th EEE Coputr ad Coucatos octs, pp , orath ad M. l, hft: gral phas tp fttg tool, procdgs of th prforac L, Lctur Nots Coputr cc, ol. 34, Lodo, UK, prl. Coprght 9 crs.. J. Coucatos, Ntwor ad st ccs, 9,, -89

11 4 R. GZZE E L. Coprght 9 crs.. J. Coucatos, Ntwor ad st ccs, 9,, -89 ppd loc atrcs of trasto atr cto 3.4 L L M L L L L L L L L

12 RRY UEUNG MEL FR CF CNRLLE CNNEL CCE CC 4 N WRELE LN Coprght 9 crs.. J. Coucatos, Ntwor ad st ccs, 9,, -89 ppd tat probablt ctors th hgh prort accss dla cto 4.3 z z z z L z z loc atrcs of trasto atr h L L L L L ppd C ccss dla strbuto for th low prort pacts cto 4.3 h arrg low prort pact wll rach th had of ts quu ad wll b rad to trast f all th low prort pacts ahad of t ar srd. c th low prort pact s uabl to b trasttd whl thr ar hgh prort pacts th sst, th arrg low prort pact has to wat for coplto of th trassso of all hgh prort ad low prort pacts whch ar th sst ad thos hgh prort pacts whch wll tr durg th prod of th t that th arrg pact os towards had of quu. hrfor, th ubr of pact ahad of arrg low prort pact at ts arral t s all hgh prort ad low prort pacts th sst cludg a hgh prort pact whch ght ha arrd otl wth t. uppos dfs tal probablt ctor th low prort accss dla.... whr L L whr, rprsts probablt of a arrg low prort pact fdg hgh prort ad low prort pact th sst wth th srr o acato ad L s th probablt of a arrg low prort pact fdg hgh prort ad low prort pact th sst wth th srr th low prort hgh prort procssg at th th slot of X. ll th probablt ctors ca b calculatd a slar ar whch has dscussd th cto 4.3. } } } L L } }

13 4 R. GZZE E L. Coprght 9 crs.. J. Coucatos, Ntwor ad st ccs, 9,, -89 L } } } } } L } rasto atr for th low prort pact accss dla: l M L L M L L L L

14 RRY UEUNG MEL FR CF CNRLLE CNNEL CCE CC 43 N WRELE LN Coprght 9 crs.. J. Coucatos, Ntwor ad st ccs, 9,, -89 uppos. h, l o rducto of coputato, th st of followg quato ca b usd. Fall, lt L W b th probablt that th watg t of low prort pact s lss tha or qual to. h, l L W.