STOCHASTIC CONGESTION CONTROL MODEL FOR VIDEO TELECONFERENCE SERVICE TRFFIC (VTST) SYSTEMS

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1 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- SOCHASC CONGESON CONROL MODEL FOR VDEO ELECONFERENCE SERVCE RFFC (VS) SYSEMS K.SENBAGAM, D.C.V.SESHAAH Asssan Pofesso, Deamen of Mahemacs,S Ramashna Engneeng College, Combaoe Pofesso and HOD of Scence and Humanes,S Ramashna Engneeng College, Combaoe ABSRAC:-A congeson conol model of a newo of sgnalzed nesecons s oosed based on a dscee me, seady sae Maov decson ocess. he model ncooaes obablsc foecass of ndvdual vdeo acuaons a downseam nducance loo deecos ha ae deved fom a macoscoc ln ansfe funcon. he model s esed boh on a ycal solaed Robeson s affc laoon nesecon and a smle newo comsed of fve fou legged sgnalzed nesecons, and comaed o full-acuaed conol. Analyses of smulaon esuls usng hs aoach show sgnfcan movemen ove adonal full-acuaed conol, esecally fo he case of hgh volume, bu no sauaed, affc demand. Keywods: Congeson conol, Maov conol ocess, affc flow, Vdeo, smulaon.. Bacgound he exsence of eal-me congeson affc conol sysems ha eac o acual affc condons on-lne, he mos noable among hese beng he well-nown OPAC algohm(gane,983 ), and RHODES, a eal-me affc congeson conol sysem ha uses a affc flow avals algohm(head,995) based on deeco nfomaon o edc fuue affc volume. n geneal, wo ssues mus be addessed o acheve eal-me congeson affc conol: () develomen of a mahemacal model fo he conol of he sochasc, hghly nonlnea VS sysem, and () desgn of aoae conol law such ha he behavo of he sysem mees cean efomance ndces (e.g., mnmum ueue lengh, mnmum delay me, ec.). Mahemacal models used fo he eesenaon of affc henomena on sgnalzed suface see newo can be classfed no he followng hee genealzed caegoes: () soe-and fowad models (Ham, 9; Sngh and amua, 6; D s Ans and Gazs, 8), () dseson-and-soe model Ceme and Schoof, 7; Chang eal., 994), and (3) nemac wave models(sehanedes and Chang, 993, Lo, ). hee ae wo fundamenal aoaches fo on-lne omzaon: bnay choce logc and he JSER h:// seuenal aoach. n he bnay choce logc aoach, me s dvded no successve small nevals, and a bnay decson s made ehe o exend he cuen sgnal hase by one neval, o o emnae. Examles of hs aoach nclude Mlle s algohm, affc omzaon logc(ol), modenzed omzed sevce acuaon saegy (OSAS), sewse adusmen of VS mng (SAVS), ec. (Ln,9; Ln and Vayauma, ). he dawbac of hs aoach s ha only consdes a vey sho fuue me neval (usually 3-6 s) fo he decson, and hus canno guaanee he oveall omzaon of he VS oeaon. n he seuenal; aoach, he lengh of a decsonmang sage s elavely longe (fom 5 o s) o moe closely aoach he long-em omal conol. n OPAC, develoed exlcly fo eal-me affc conol, he alenave dsadvanages of he bnay and seuenal aoaches ae mgaed by ncooang a ollng-hozon aoach; howeve, s alcaon fomally s lmed o solaed nesecons. Afcal neual newos (ANN) also have been aled o fndng he soluon fo affc conol oblems (Naasu and Kau, 7) hough an assumed mang beween he conol vaables (e.g., he sl) and he obecve funcon (e.g., he ueue lengh); he neual newo s aned off-lne, usng he nonlnea mang ably of ANN, o ealze hs elaonsh. hen he sgnal

2 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- omzaon s efomed on-lne, usng he selfoganzaon oey of an ANN. he anng algohm s a sewse mehod(combnaon of a Cauchy machne and he bac-oagaon algohm). Howeve, hs aoach s vald only when he affc sysem s n seady sae.. noducon A a sgnalzed nesecon, VS oeaes n one of hee dffeen conol modes: n e-mes conol, sem-acuaed conol and full-acuaed conol (Wlshe eal., 6). n e-med conol, all of he conol aamees ae fxed and ese off-lne. Off-lne echnues (e.g., he vaous vesons of he RANSY (Robeson ) famly of sofwae acages) ae useful n geneang he aamees fo fxed mng lans fo convenonal e-med uban affc conol sysems based on he deemnsc affc condons dung dffeen me eods of he day (e.g., ea hous, off-ea hous). n acuaed (boh sem- and full-) conol, he conol sevce s adused n accodance wh a closed-loo, on-lne conol saegy based on eal-me affc demand measues oband fom deecos; whle he conolles hemselves esond o he flucuaons of he affc flows n he newo, he base aamees do no. Alenavely, a class of conol algohms ha ncludes SCOO (Sl, Cycle And Omzaon echnue) (Hun() eal., 8; Robeson and Beheon, ) and CCS (Coodnaed Congeson affc Sysem) () (Lowe, 6) ae geneally consdeed o be Onlne algohms, n whch he conol saegy s o mach he cuen affc condons obaned fom deecos o he bes e-calculaed off-lne mng lan. JSER h:// decson conol, s noduced. he obecve s o develo a eal-me congeson conol saegy ha exlcly ncooaes he andom naue of he affc sysem n he conol. A Maov conol model s fs develoed; hen he sgnal conol oblem s fomulaed as a decson-mang oblem fo he Maov model. hs aoach s esed boh on a ycal solaed affc nesecon and a smle newo comsed of fve fou-legged sgnalzed nesecon movemen ove adonal full-acuaed conol, esecally fo he case of hgh volume affc demand. 3. Maov Sevce affc Conol Model A sochasc ocess x() s called Maov (Paouls, 6) f s fuue obables ae deemned by s mos ecen values;.e., f fo evey n and < <... < n P(x( n ) x n /x() x n-, ) = P(x( n ) x( n-)). he congeson conol algohm oosed s based on a dscee, saonay, Maov conol model defned on (X, A,P,R), whee X, a Bownan sace s he sae sace and evey elemen n he sace x X s called a sae; A, also a Bownan sace, s defned as he se of all ossble conols( o alenaves). Each sae x X s assocaed wh a non-emy measuable subse A (x) of A whose elemens ae he admssble alenaves when he sysem s n sae x; () P, a obably measue sace n whch an Alhough mos exsng congeson sgnal elemen denoes he anson obably fom conol saeges ncooae an mlc sae o sae unde alenave acon ; and ecognon ha affc condons ae me vaan (v) due o Sochasc ocesses, hey geneally ado R, a measuable funcon, also called a one-se ewad. exlcly deemnsc conol models. Selecon of a acula alenave esuls o an Addonally, mos emloy heusc conol mmedae ewad and a anson obably o saeges wh an embedded affc flow model. he nex sae. he oal execed dscouned Alenavely, he andom naue of he affc sgnal ewad ove an nfne eod of me s defned as lends self moe decly o a sochasc conol aoach. n he wo eoed hee, a sochasc affc sgnal conol scheme, based on Maovan

3 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- 3 D E x, h () Whee ( ) s he one-se anson ewad, ( ) s he dscoun faco, and h s he olcy. he omal ewad d *, o he suemum (leas ue bound) of D, s defned as d * ( x, h ) * su D x, h h A () can be obaned by solvng a funconal euaon (also called he dynamc ogammng euaon, o DPE): * * d d (3) Whee s a conacon oeao and d( x) max x, h d x (4) h A N he execed one-se anson ewad x, h s defned as N x, h (5) h h he unue soluon of he above DPE can be calculaed eavely by he successve aoxmaon mehod (Henandez- Lema,8) d n x h A N n h max x, h d x (6) heefoe, fo a secfc conol oblem, once he anson max and he ewad max ae defned, hen by maxmzng he oal execed ewad, a olcy fo choosng an alenave fo each sae can be obaned. hs eesens he omal saegy ha should be followed. 4. affc Flow Consde he ycal fou-legged solaed affc nesecon shown n Fg., whee he vaous ossble affc movemens. he sae euaon fo he connuous affc flow ocess assocaed wh any h movemen ha s samled evey seconds, whee me s ndexed wh he nege, can be exessed by he cuen ueue : (7), =,,., 8, Fg.. A ycal vdeo affc nesecon. whee beween he nu n dung me neval,, and s he dffeence n and he u ueue a evous me nsan s he. Fo a ycal fou-legged affc nesecon wh egh movemens, he cuen ueue can be fuhe defned by he veco 8,,, (8) whee me ( ) s used o denoe ansose. he nu n and u of he nesecon (.e., numbe of vdeo confeences eneng/leavng he nesecon) can also be smlaly defned as vecos of le dmenson:, n n (9) he u can fuhe be exessed as a funcon of he cuen conol of he nesecon, c, and he cuen ueue, : f c, () JSER h://

4 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- 4 Whee s also a veco of he same dmenson,.e., Fg.. Egh-hase dual-ng sevce conol f () and whee he elemens f ae deemned by f mn ;, c h mn, c () n whch hmn s he mnmum head way and c s a dchoomous vaable ndcang he conol h sgnal fo he movemen: c denoes ha he h movemen has he geen sgnal and ndcaes a ed sgnal. c Unde sandad egh-hase dual-ng conol(fg.), he bae dvdes he egh hases no wo neloced gous(ngs):eas/wes and noh/sh: n each ng, fou movemens(wo hough movemens and he coesondng lefun movemens) mus be seved f hee s demand. Alhough hee ae.4!=48 dffeen hase seuences avalable, deendng on he affc demand, he ng and bae ules esc he maxmum numbe of hase anson n a sngle cycle o sx- a maxmum of hee dsnc hase combnaons on each sde of he bae. Usng hs nfomaon, he hase seuencng consans on choce of he cuen conol deends, a mos, on hee evous conol sgnals: c fu,, c, c, c 3, (3) Whee s he me duaon of he mos ecen evous hase, s he me duaon of he nexo-las hase, and so on. n addon o he seuencng consans, he duaon of he cuen sgnal, mus be bounded beween some mnmum (e.g. mnmum geen, mnmum geen exenson) and (maxmum geen) me eod: τ mn τ τ max (4) hs schema easly can be genealzed o affc newo wh mulle nesecons. n a affc newo wh n nesecon, he ode of he dynamc euaon s nceased o n x 8(assumng ha hee ae egh affc movemens n each nesecon). Howeve, any comlcaed affc newo can be decomosed no a gou of small elemenay newos as shown n Fg.3, conssng of fve nesecons. n hs manne he sudy of he ene affc newo can be educed o he analyss of hese elemenay newos and he ne-connecons beween hem. he comlee affc dynamc model fo he newo shown n Fg.3 c c, c,, c 5 f f, f,, f c c c c5 JSER h://

5 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- 5 n n,,, n n,,, (5) 5 5 examle, consde he smle case of he wo adacen nesecons shown n Fg. 4. Fg.4. A affc newo wh wo nesecons,,, 5 f f, f,, f 5 Fg.3. A ycal elemenay affc newo wh fve nesecons. whee f f c, (6) mn ;, c, h mn, c =,,,5; =,,,8 (7) n E. (5), he subscs o he vaous veco uanes efe o he acula nesecon, and he veco uanes hemselves ae as evously defned. Unle he case of an solaed nesecon, he neacons beween nesecons mus be ncluded n he affc model fo hs case. Fo he egh affc movemens assocaed wh each nesecon can be classfed no wo dffeen yes:. Exenal movemen. he aval vdeos come fom/go o a dummy node sde he newo (hese vdeo can be consdeed as he nu/u of hs newo); and. nenal movemen. he aval vdeos comes/goes o a neghbong node nsde he newo(hese vdeo can be consdeed as he neconnecon of hs newo). Fo examle, movemens and 6 ae nenal movemens of nesecon, whch eceve he us fom nesecon, movemens 3 and 6. All of he ohe movemens of nesecon one ae exenal movemens. Smlaly, all of he movemens of nesecon ae exenal movemens, wh he exceon of movemens and 5, whch eceve he u fom he movemens and 7 of nesecon. hen, fo nesecon, he nenal movemens ae defned by 3, , f, n n,,,,,,,, (8) 6 3, , n fn,,,,,,,,,, whee, s defned as he vdeo movng facon fom nesecon, movemen o nesecon, movemen and whee, eesens he me fo he fs vdeo confeence n he laoon of vdeo n movemen of nesecon o each nesecon. JSER h://

6 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- 6 he me- deenden movng facos can be eesened by he movng facon max,, whose elemens ndcae he ecenage of vdeo movng fom a cean movemen a he useam nesecon o a secfc movemen a he downseam nesecon. Fo he case of wo nesecons shown n Fg. 4, as a 6x6 max: whee,, 3,, 6,, =,, 7,,,,,,,,,5, 7,5, 3,6, 6,6, can be wen (9) Usng hs geneal exesson fo f,, M, m, n n m, m, m m, m () whee s he se of all neghbong nesecons wh dec aoaches o nesecon, and M m s he se of all movemens of nesecon m ha JSER h:// conbue o he nenal movemens of nesecon. Paccal alcaon of E. () eles on he ably o edc boh he me-deenden movng facons,, and he laoon avel mes fom neghbong nesecons o he age nesecon,. he esmaon of movng facons fom, coun daa has been he subec of numeous nvesgaons; see, e.g., he evew ovded by Mahe(984) fo a oosed of models ha eue couns fo only one cycle bu needed o unng ooon esmaon. Davs and Lan (995) gave a mehod ha esmaes nesecon unng movemen ooons fom less-han-comlee ses of affc couns. Chang and ao (997) oose a me-deenden unng esmaon ha ncooaes sevce mng aamees on he dsbuon of nesecon flow. Mchandan eal. () gave fou closed-fom esmaon mehods:() maxmum enoy(me), () genealzed leas suaed(gls), () leas-suaed eo(ls), and (v) leassuaed eo/ genealzed leas suaed eo(ls/gls). n s basc model eesenaon: Q F Q F Q () whee F avg and whee Q, Q ae affc volumes a he downseam and useam nesecons(measued n vdeos/h), esecvely; α and β ae called laoon dseson aamees; s he nal me when he laoon leaves useam nesecon; avg s he aveage avel me, and s he mnmum avel me beween he wo nesecons. = β avg () Subsung Robeson s laoon dseson fomula no E.() leads o F F (3) n, m, m, m m, n Mm m wh he cuen conol veco defned by c f c,, c, c, c 3 (4)

7 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- 7, whee mn max, m, can be deved fom couns fom useam solne deecos accodng o exsng ocedues dscussed evously, and whee he, ae deemned by E. () fom m aamee secfcaon and aveage avel seed. 5. Maov congeson conol model fo VS sysem he sae vaable n he affc dynamcs euaon develoed above s ueue lengh. Alhough he sae of he Maov conol model can be defned as he numbe of vdeo confeence n he nesecon, hs aoach esuls n an excessvely lage numbe of saes, even fo a sngle nesecon. o addess hs oblem, he sae of he Maov conol model s nsead defned by noducon of a bnay heshold value (numbe of vdeo confeences) ndcang whehe of no he cuen ueue fo a acula movemen s suffcenly lage o be congesed,.e., f he ueue lengh of a secfc movemen s geae han s heshold value, hen he movemen s n he congesed mode ; ohewse s n he noncongesed mode. hese bnay modes (congeson/non-congeson) ae defned as he wo saes n he sae sace X. Snce he sae sace s dscee, he obably measues P s a dscee anson law, and he obably max P s me-vayng affc flow. A me se, P s a funcon of, and c : P f,, c (5) n whee s he cuen ueue, s he esmaed numbe of avals n he nex me neval, and c s he conol sgnal. Assumng ha a me se, he cuen ueue lengh of a secfc movemen s denoed by ; and g vdeo JSER h:// can ass hough he nesecon f he affc sgnal fo hs movemen s geen; hen he anson obably fom any cuen sae (ehe congesed o non-congesed) o he non-congesed sae unde conol sgnal c can be wen as c S N n g heshold P c (6) and, o he congesed sae, as Whee c c (7) S C S N, when c G c (8), ohewse. n he above, heshold s he heshold whch defnes he congesed/non-congesed sae; S s he cuen sae ( Nfo non-congesed sae and C fo congesed sae); c s he conol sgnal ( G fo geen sgnal and R fo ed sgnal). wo secal cases ae noed n ha: R R and (9) C C C As menoned evously, fo a ycal affc nesecon wh egh ndeenden movemens, he oal numbe of saes s 8 = 56. he anson obably fo each movemen s also ndeenden; heefoe, he oveall anson obably fo an nesecon s whee N 8 c c Sae Sae S S (3),=,,,56; and c =[u,u,,u 8 ]. he ewad max R has he same dmenson and a defnon smla o ha of he obably max. he conol obecve s o manan he noncongesed condon o, f aleady congesed, o ans o a non-congesed sae. he lae yelds a geae ewad han he fome and he anson fom a non-congesed sae o conges caes a geae enaly han emanng n a congesed sae. Snce he congesed/non-congesed sae s defned n ems of ueue lengh, he ewad max s a

8 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- 8 funcon of he cuen ueue, he heshold, and he conol sgnal: R f, heshold, c (3) Fo examle, f he obecve s o mnmze he ueue lengh, hen he ewad fo each ossble case can be chosen as he followng: M G N R N N N M G N C M R N G C C N 3 M 4 M R C G C N C 5 N. A. M R N N 6 M 7 Whee M, =,,,7, ae consans whch can be secfed fo a secfc conol oblem. Smla o he obably max, he oveall ewad fo an nesecon wh egh ndeenden movemens s 8 c c Sae Sae S S, whee =,,,56., (3) he sgnal hase ae he dffeen alenave fo each sae; fo a ycal solaed affc nesecon wh egh ndeenden movemens unde egh-hase dual-ng sgnal, he sgnal conol oblem aes he fom of a 56-sae Maov ocess wh egh alenave fo each sae. he omal olcy s hen obaned by selecng he alenave fo each sae ha maxmzes he oal execed ewad. As has been demonsaed above, hs omal soluon s unue and can be calculaed eavely by he successve aoxmaon mehod. he oosed Maov conol model can be llusaed by he smlfed examle of he wohase solaed nesecon shown n Fg. 5, n whch affc flows along wo decons,.e., noh/sh (denoed by ) and eas/wes (denoed by ). hus, hee ae fou ossble sae,.e., NN, NC, CN, CC. Fg. 6 shows he schemacs of hs Maov Chan. o smlfy he examle, ambe dslays and all ed sgnals ( RR ) ae gnoed; GG s ohbed fo obvous easons. Unde hese condons, hee ae wo alenaves (sgnal hases) n each sae,.e., GR and RG. Wh he usual assumon of Posson avals, he vaous anson obables can be calculaed decly. Fo examle, he anson obables fom he non-congesed saes ae G N G N C N n heshold g n n! heshold G G N C N N n n n! e e (33) R R, N C N N, (34) Fg.5. An solaed nesecon wh hough movemens only whee n s a osve nege ( n =,, ); s he aveage vdeo aval ae and s he me neval (.e., duaon of each counng eod). he coesondng sae obables ae, G R G R NN NN N N N N, G R G R NN NC N N N C (35) JSER h://

9 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- 9 Fg.6. he Maov Chan fo he examle Snce, fo hs examle, hee ae fou saes wh wo alenaves fo each sae, he elemens above fom an 8x4 anson obably max, as shown n able. Elemens of he ewad max can be calculaed n smla fashon. A geneal bloc dagam of conol usng hs scheme a an solaed sgnalzed nesecon s llusaed n Fg.7. Based on he cuen and he esmaed affc flow, he conolle geneaes a affc conol sgnal o conol he affc sysem fo he nex me neval. Fg. 7. affc conol a sgnalzed sysem me neval based on he cuen measuemen fom he deeco, as well as he esmaon. Once he omal olcy s found, s mlemened fo one me se(.e., seconds). A he nex me neval, boh he obably max and ewad max ae udaed and he whole decson mang ocess s eeaed. able. he sae obably max fo he examle Sae NN NC CN CC GR NN GR GR GR N N NN NN NC N N C C NC RG RG N N N N GR RG CN GR RG GR CC GR C C C C RG RG C C C C n he alcaon of hs ocedue o ealme congeson conol fo a affc sysem, he me-vayng obably max P and he ewad max R ae calculaed and udaed evey seconds; a decson s hen made egadng he choce of he conol sgnal fo he nex Fg.8. affc conol fo wo nesecons o enfoce he hase consans, a se-byse decson-mang ocedue (also emed a decson ee ) s emloyed. Fo examle, a decson s made fs o deemne whch ng wll be seved by he Maovan decson algohm. Afe hs s deemned, he second decson s o choose one of he fou alenaves fom he fs decson, agan usng he Maovan decson algohm. he nex hase s ehe fxed o can be chosen fom he wo hases lef, deendng uon he second decson. A he las decson se fo hs ng, hee s ehe no hase o us one fxed hase JSER h://

10 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- lef. hs ocedue no only guaanees he hase consans bu also damacally educes comuaon me. Alcaon of he decson conol o he sgnal conol of a newo of mulle nesecons oceeds along a smla manne; a bloc dagam fo he conol sysem of wo affc nesecons s shown n Fg.8. n such cases, he conol sgnal of he wo neghbong nesecons do no neac unl some mnmum avel me, a whch me he conol s modeled hough he obably esmaon of nenal movemen avals a he downseam nesecons. ha s, assumng ha he mnmum avel me beween wo nesecons s longe han he mnmum geen exenson me, he conol sgnals of he wo nesecons do no neac due o he andom avel me delay beween hem. Afe he mnmum avel me, he conol a one nesecon does affec nesecons downseam; hs effec s modeled n he obably esmaon a he downseam nesecons. As a esul, adacen nesecons can be solaed and he esecve conol acons can be seaaely. 6. Resuls on alcaon of Maov congeson model n hs secon, he conol model s esed by smulaon on boh an solaed affc nesecon and a ycal affc newo wh fve neconneced nesecons o evaluae s efomance wh esec o convenonal fullacuaed conol. Secfcally, a sees of comue smulaons ae efomed, unde vaous dffeen vdeo aval aes, and he means and vaances of he esecve efomance measues of he convenonal and oosed congeson conol algohm ae analyzed. he smulaons assume ha ueues on all aoaches ae emy as an nal condon and ha vdeo avals on exenal aoaches follow a Posson dsbuon; fo demonsaon uoses, a value of heshold = (.e., he esence of any ueue) was assumed. he ewad max was based on he obecve beng o mnmze he ueue lengh, and he ewad JSER h:// calculaed accodng o E.(3). n he case of he newo smulaon, he dsance beween any wo adacen nesecons s chosen o be fee. he aamees used n he smulaon (fo all he movemens) ae summazed as follows: Usng he same se of nu (aval) daa, he Maovan conol algohm and he convenonal full-acuaed conol wee aled o a fou-legged solaed affc nesecon, such as ha shown n Fg., wh egh movemens(fou hough movemens and he coesondng lef-un movemens) o evaluae he efomances. he algohm used o smulae full-acuaed conol was desgned o mmc he logc of a common ye 7 dual ng conolle wh aamees as secfed n he evous able-egh-hase oeaon was assumed. o mnmze nal condon effecs, he wo algohms ae aled fo a smulaed me of 65 mn., and he aveage delay (e vdeo) dung he las dve mnues of he smulaon s used fo comason. wo dffeen geneal cases wee consdeed: () unfom demand among all conflcng movemens, and () he hough affc demand domnaes he lef-un demand by a ao of :. he wo algohms wee aled fo dffeen aval aes, eesenng a ange of boh unsauaed and sauaed condons.(unde he assumon of -second mnmum headways, he nesecon has a oal caacy of 36 vdeos e hou of geen). n ode o ovde sascal sgnfcance fo he smulaon esuls, he wo algohms wee esed on dffeen ses of andom daa fo each aval ae ( a oal of foy on he cases n whch lef-movng affc was assumed eual o hough affc, and ffeen n he cases n whch lef-movng affc was eual o half of he hough affc). he means of he aveage delay e vdeo fo he fnal- mnue eod of each se of foy smulaons coesondng o he wo cases of lefmove o hough affc of.(lm/=.) and.5(lm/=.5) ae loed n Fg. 9, whee MCC sands fo he Maov congeson conol algohm and FAC sands fo he full-acuaed conol. As a fuhe benchma comason, delay calculaons based on Webse s delay euaon fo Posson avals unde fxed-me (e-med) conol ae

11 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- also ovded (labeled Pe (C=6s) and Pe(C=45s) fo cycle lenghs of 6 and 45 s, esecvely. Sgnfcance ess based on -sascs esulng fom hyohess ess on he dffeence of samle means ndcae ha he dffeence n means of he smulaon esuls s sgnfcanly dffeen (a.5 level o above) fo all cases exce fo he LM/ =. case n whch he oal nesecon volume 5vh. he hyohess ess on he dffeence of means assume ha he wo oulaons ae ndeenden and have a nomal dsbuon. Alenavely, ode sascs (dsbuon-fee sascs) esmae he lms whn whch a cean ecenage of he obably of he andom vaable wh a cean degee of confeence wh havng o nowledge of he obably dsbuon. Fo he case nvolvng 4 samles aen fom a algohm s sgnfcanly bee han he fully acuaed conolle(as well as he e-med conolle). Fo examle, fo LM/=., when = 3, he Maov algohm shows ab a 5% movemen on he aveage seady sae delay; fo = 4 and = 5, he aveage seady sae delay of he Maov conolle s only ab one half of ha of he full-acuaed conolle. As execed, unde sauaed condons boh algohm exhb nceasngly wose delay, alhough he Maov conol (on aveage) sll efoms fullacuaed conol. he smulaon esuls ndcae ha by alyng he Maov Fg..Ue and lowe bounds on smulaon esuls Fg.9. Algohm efomance comason fo solaed nesecon oulaon, he ue/lowe bound whn whch 9% of he obably of he andom vaable les can be obaned wh 95% confdence. Fg. dslays hese bounds on he seady sae delay esulng boh fom full-acuaed and fom Maovan conol algohms. Fom he above fgues, exce fo he case n whch he lef-move affc volume s eual o he hough volume (LM/=.) and he volume s elavely lgh(e.g., aval ae s vdeo /hou/movemen), he efomance of he Maov congeson conol algohm, he aveage delay a an solaed nesecon may be educed damacally (-5%). he Maov congeson conol algohm was also esed on a ycal affc newo of fve nesecons, such as ha deced n Fg.3. Fo hs case, Posson avals wee assumed a he exenal nus; he avals a all neval aoaches ae an come of he conol saegy emloyed a assocaed useam nesecons. he ess wee JSER h://

12 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- conduced fo LM/ =. usng fve dffeen aval aes: =,3,4,5 and 6 vdeo e hou e movemen. he nenal aoaches lnng he fve nesecons wee assumed o be f n lengh, and he aveage avel seed assumed o be 3mh(esulng n a value of avg =3s). he aamees n Robeson s laoon dseson model wee assumed o be α =.35, β =.8 he common defaul values fo ndan sudes. he mean values(of he 4 ses of daa ) of he seady sae delay ae loed n Fg.. he doed lnes n Fg. dslay he ue/lowe bounds whn whch 9% of he obably of he seady sae delay esulng boh fom full-acuaed and Maovan conol algohms lay. he esuls ndcae ha he Maov algohm subsanally efoms adonal fullacuaed conol, aculaly when he nesecon s a, o nea sauaon. Fo examle, when 5(oal nesecon volume of 4vh), he aveage seady sae delay of he Maov conolle s only ab one half of ha of he fully acuaed conolle. Unde heavy ove-sauaed condons ( =6), delay wh boh algohms end o convege a a hgh value. We noe ha, unde smle fve-node newo condons wh dencal aval aes, he efomance of he Maov conol algohm closely mos ha obaned n he case of he solaed nesecon examle (Fg.). Alhough elmnay, he esul sugges ha alcaon of he algohm n a newo seng ends o decease vaably n efomance; hs s execed, snce he vaably exessed n he Posson aval aens a he exenal nodes becomes as nceasngly mno faco as he numbe of nenal aoaches nceases. hs lae faco may hel o exlan he lage vaance seen n he solaed nesecon case unde heavy ovesauaon. Fg. 3. Maxmum ueue comason (3 vh) Fg.. Algohm efomance comason fo smle newo case Fg.. MCC efomance comason beween newo and solaed nesecon examles As saed evously, he secfc obecve used n hese examles of alcaon of he Maov congeson conol algohm was no secfcally o mnmze delay, bu ahe o mnmze he ueues on he nesecon aoaches; he delay efomance chaacescs esened above wee an ancllay come of he secfc obecve. Relave o efomance elaed o ha secfc obecve, Fg.3 esens eesenave values of he maxmum ueues fo each movemens obaned JSER h://

13 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- 3 fo he newo case n whch he oal nesecon volume s 3vh, o ab 9% of nesecon caacy. he esuls ndcae ha he Maov congeson conol algohm sgnfcanly efoms full-acuaed conol n hs asec, alhough mus be noed ha full-acuaed conol s no exlcly desgned o mnmze ueue lengh, bu ahe mlcly wos owads hs end va s exenson sengs. 6. Summay and conclusons affc sgnal conol s a mao AMS comonen and s enhancemen aguably s he mos effcen way o educe suface see congeson. he obecve of he eseach esened hee has been o esen a moe effecve sysemac aoach o acheve eal-me congesed sgnal conol fo affc newos. n hs eseach, he oblem of fndng omal VS mng lans has been solved as a decson-mang oblem fo a conolled Maov ocess. Conolled Maov ocesses have been used exensvely o analyze and conol comlcaed sochasc dynamcal sysems; s obablsc, decson mang feaues mach almos efecly wh he desgn feaues of a affc sgnal conol sysem. he Maovan decson model develoed heen as he sysem model fo sgnal conol ncooaes Robeson s laoon dseson affc model beween nesecons and emloys he value eaon algohm o fnd he omal decson fo he conolled Maov ocess. Analyss of comue smulaon esuls ndcaes ha hs sysemac aoach s moe effcen ha he fullacuaed conol, esecally unde he condons of hgh affc demand. hee ae,of couse, sgnfcan lmaon o he esen aoach. Mos noable s ha as he sze of he affc newo nceases,.e., he numbe of nodes/nesecons and /o lns nceases, he dmensons of he Maovan conol model nceases damacally, eung moe memoy sace and comuaon me. hs dmensonaly ssue s vey moan o eal-me mlemenaon, whee ocessng seed s cucal. n he cuen fomulaon, one oenal soluon o hs oblem s alluded o by decomosng he newo no ses of ne-lned newo enels of fve nesecons ha could be handled by dsbued/aallel ocessng oocols; howeve, no aem has been made o hooughly nvesgae he ssues of such decomoson algohms. Fuhe, befoe any aem o mlemen he esuls, a comehensve sensvy analyss needs o be conduced o sudy he effecs of he vaous aamees emloyed n he smulaon esng on boh he efomance of he model as well as on he obecve funcon. Fnally, fo feld esng, he ognal C language code mus fs be ewen no assembly language; hen fmwae can be loaded, o buned n o he PROM (Pogammable Read Only Memoy) ch of he conolle. he wo can be exended o mulsage affc flow confeencng. Refeences [] Aboudolas,K, Paageogou.M, Kosmaooulos.E, Conol and Omzaon Mehods fo affc Conol n Lage-Scale Congesed Uban Road Newos, Amecan Conol Confeence, EEE ansacons on 7(33-338). [] B.Hoh, M.Guese, R.Heng, J.Ban, D.Wo, J-C. Heea, A.Bayen, M.Annavaam and Q.Jacobson, Vual lnes fo dsbued vacy-esevng affc monong, n 6 h nenaonal Confeence on Moble sysem, Alcaons and Sevces (Becendge,CO),. 5-8, June [3] Camonogaa.E, de Olvea.L.B, Dsbued Omzaon fo Model Pedcve Conol of Lnea- Dynamc Newos, Sysems, Man and Cybenecs, Sysems and Humans, EEE ansacons n 9(33-338). [4] Chang.G and X.ao. Esmaon of me- Deenden unng Facons a Sgnalzed nesecons. ansoaon Reseach Recod 997, 644(), [5] Chen.A, Choonan.P, Rece.W, 5. Esmang he ualy of synhec ogn-desnaon able esmaed by ah flow esmao, Jounal of ansoaon Engneeng, Amecan Socey of cvl Engnees 3 (7), [6] Davs.G.A, Lan.D.C,995, Esmaon nesecon unng movemen ooons fom less-han-comlee JSER h://

14 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- 4 ses of affc couns, ansoaon Reseach Recod 5, [7] D.Wo, O.P. ossavanen, Q.Jacobson and A.Bayen, Lagangan sensng: Dsbued affc esmaon wh moble devces. Acceed fo ublcaon, ACC Amecan Conol Confeence, 9, San Lous, MO. [8] D.Wo, O.P. ossavanen, S. Blandn,A, Bayen,.Llwuchuwu and K.acon, An ensemble Kalman fleng aoach o hghway affc esmaon usng GPS enabled moble devces, n Poc. Of he 47 h EEE Confeence on Decson and Conol, (Cancun, Mexco). [9] Dal Yue, Dongbn Zhao, A affc Sgnal Conol Algohm fo solaed nesecons based on Adave Dynamc Pogammng, CNSC, nenaonal EEE Confeence on. [] H.Gaul and.aylo, he use of u fom vehcle deecos o access delay n comue- conolled aea affc conol sysems, ech.re. Reseach Reo No.3, ansoaon Oeaon Reseach Gou, Unvesy of Newcasle Uon yne, 977. [] Henclewood.D, Hune.M and R.Fumoo. 8. Poosed Mehodology fo a Daa-Dven Smulaon fo Esmang Pefomance Measues Along Sgnalzed Aeals n Real-me, 8. [] Juh-Bng Sheu, A sochasc omal conol aoach o eal-me, ncden-esonsve affc sgnal conol a solaed nesecons, anso Scence. [3] Kalge Wen, Shu Qu, Yumel Zhang, A sochasc adave conol model fo solaed nesecons, Robocs and Bommecs, nenaonal EEE Confeence on 7. [4] L.Mhaylova, R.Boel and A.Hegy, Feeway affc esmaon whn ecusve Bayesan famewo, Auomaca, vol.43, no.,. 9. [5] Lu.H.X, W.X.Ma and H.H.Wu, Develomen of a Real-me Aeal efomance Monong Sysem Usng affc Daa Avalable fom Exsng Sgnal Sysem, Queue Mnneaols on 9. [6] Lu.H.X and W.X.Ma 7, me-deenden avel me Esmaon Model fo Sgnalzed Aeal Newo, RB Annual Meeng 7 (vol.,.). Washngon DC: Naonal Academes. [7] Lu.H.X and W.X.Ma 7, me-deenden avel me Esmaon Model fo Sgnalzed Aeal JSER h:// Newo, RB Annual Meeng 7 (vol.,.). Washngon DC: Naonal Academes. [8] Lo.H.K,. A cell-based affc conol fomulaon: saeges and benefs of dynamc mng lans, ansoaon Scences 35 (), [9] Lowe.P, 98, he Sydney coodnaed adave conol sysem-ncles, mehodology, algohms. n: EEE Confeence Publcaon, 7. [] Mahe.K.J, 984. Esmang he unng flows a a uncon: a comason of hee models, affc Engneeng and conol 5, 9-. [] P B. Mchandan, S A.Nobe, W. Wu,, he use of on-lne unng ooon esmaon n eal-me affc-adave sgnal conol, ansoaon Reseach Recod78, [] P.Cheng, Z.Qu and B.Ran, Pacle fle based affc sae esmaon usng cell hone newo daa, n Poc. EEE nellgen ansoaon Sysems Confeence SC 6,.47-5, 6. [3] P.Hao, X.Ban, R.Heng and A.Bayen, Delay aen esmaon fo sgnalzed nesecons usng samled avel mes, n 9 ansoaon Reseach Boad Annual Meeng, (Washngon,D.C.), 9. [4] Paouls. A, 984. Bownan movemen and maoff ocess. Pobably, Random vaables and Sochasc Pocesses, second edon, McGaw-Hll, New Yo, [5] Robeson.D., Beheon.R.D,, Omzng newos of affc sgnals n eal-me: he SCOO mehod, EEE ansacon on Vehcula echnology 4,. [6] S.Vayauma, Adave sgnal conol a solaed nesecons, Jounal of ansoaon Engneeng. [7] Sngh.M.G, amua.h, 974. Modellng and Heachcal omzaon fo ovesauaed uban oad affc newo. nenaon Jounal of Conol (6), [8] Sehanedes.Y.J, Chang.K.K, 993. Omal conol of feeway codos. Jounal of ansoaon Engneeng 9(4), [9].Pa and S.Lee, A Bayesan aoach fo esmang ln avel me n uban aeal affc newo, Lecue noes n comue scence,.7, 4.

15 nenaonal Jounal of Scenfc & Engneeng Reseach Volume 3, ssue 7, July- 5 [3] V.Ssou and N.Rouhal, avel me esmaon fom loo deeco daa fo advanced avele nfomaon sysem alcaons, ech. Re., llnos Unvesy ansoaon Reseach Consoum, 994. [3] We Cheng, Xaolan Lu, Wenfeng Zhang, An omal adave affc sgnal conol algohm fo nesecon, nellgen Conol and Auomaon 6. [3] Wlshe.R, Blac.R, eal, 985. affc conol sysems Handboo, FHWA-P-85-. [33] Yu, Ne, Zhang.H.M, Rece.W.W, 5, nfeng Ogn-desnaon maces wh a decouled GLS ah flow esmao, affc Reseach Pa B: Mehodologcal 39 (6), JSER h://