RADIOENGINEERING, VOL. 7, NO., APRIL 28 73 Coon Virual Pah and I Exedience for VBR Video Traffic Erik CHROMÝ, Ivan BAROŇÁK De. of Telecounicaion, Faculy of Elecrical Engineering and Inforaion Technology Brailava, Ilkovičova 3, 82 9, Brailava, Slovakia chroy@kl.elf.uba.k, baronak@kl.elf.uba.k Abrac. The aer deal wih uilizaion of coon Virual Pah (VP for variable bi rae (VBR video ervice. Video ervice i one of he ain ervice for broadband nework. Reearch i oriened o aiical roerie of coon and earae VP. Searae VP ean ha for each VBR raffic ource one VP will be allocaed. Coon VP ean ha for ulile VBR ource one coon VP i allocaed. VBR video raffic ource i odeled by dicree Markov chain. Keyword NGN, ATM, Qualiy of Service, coon Virual Pah, VBR video raffic, Markov odel.. Inroducion Video counicaion i one of ain ervice for broadband nework. Variable bi rae (VBR i yical for video raffic [3], [4], [5]. Ouu rae fro coder can vary ignificanly, o allocaion of a required channel bandwidh i robleaic. Video raffic i relaively able, bu here are oe ie eriod wih ignificanly higher channel bandwidh requireen. Thi variabiliy offer a oibiliy of aiical ulilexing gain iroveen and i i an advanage of VBR coding. The diadvanage i ha here i a robabiliy of cell lo. Thee loe occur when ulile VBR ource will overload he ulilexer. A decreae of cell lo for ource wih bur raffic i oible by ue of buffer, bu very high caaciy can be required. Alo a delay, which ha iac on qualiy of video raniion, can occur when buffer are ued. The efficien channel bandwidh uilizaion offer a queion if we can ave oe channel bandwidh by ue of coon Virual Pah over ue of earae Virual Pah for VBR raffic ource. 2. Model of VBR Video Traffic Source Modeling of video raffic ource i a neceary ar of a raffic reearch. The raffic ource odel decribe aiical roerie of a raffic flow and i allow u o decribe he raffic ource by ue of araeric value. I i neceary o ae araeer of a aheaical odel ha ee raffic characer. The final aheaical odel will be ued in iulaion analyi in iulaion environen MATLAB. Paraeer of video raffic odel fi he real video ource Ice age DVD []. Baed on he ehod rooed in [2], he following raffic odel araeer are calculaed: he raniion arix P = [ ] he vecor of he ae value of he video raffic odel = [,, M ] where M rereen he nuber of ae in Markov chain,,..., M are he ae of he video raffic odel and rereen generaed cell rae. The original equence {x } u be ranfored o dicree ae before couaion of he raniion arix and he vecor of ae, according o he following forula: y = x in x y = M ax x in x if x = in oherwie where in and ax rereen he inial or axial value in he original equence {x }. We alo need araeer M during ranforaion of he original equence o he dicree ae (he reul i a e of digi...m. For he creaed equence we can calculae raniion arix P according o he following equaion: x (
74 E. CHROMÝ, I. BAROŇÁK, COMMON VIRTAL PATH AND ITS EXPEDIENCE FOR VBR VIDEO TRAFFIC N = = M N k = = ( y, i, y, j + ( y, i, y, k + where are he coonen of he raniion arix P, (y, i, y +, j rereen an indicaion funcion for y = i and y +i = j hrough =,, N- and i, j {,,M}. The vecor of ae value [..., ] calculaed a follow: N = i = N = ( y, i x ( y, i, M (2 = i where (y, i rereen he indicaion funcion for y = hrough =,,N and i {,,M}. For M=7 we have he following aheaical odel of VBR video raffic ource:.7888.478.7256 P =.7877.7933.75.472.4595.245.872.733.25..439.976.85.29.233.7.24.9...28.3.7.2.3.5 The vecor of ae ha he following value: = 26.873 kbi/, 2 = 75.7 kbi/, 3 = 35.687 kbi/, 4 = 89.924 kbi/, 5 = 24.49 kbi/, 6 = 32.333 kbi/, 7 = 389.52 kbi/. The coure of he creaed raffic odel for M=7 i hown in Fig.. Fro hi figure we can ee ha we need ignificanly ore ae of he aheaical odel of video raffic in order o cach all roerie of real VBR raffic ource, bu for our reearch on exedience of coon VP for VBR ource hi odel i ufficien. Traniion Rae [kbi/] 3.5 3 2.5 2.5.5 4 x 5 2 4 6 8 2 Arrival of Video Paern x 4 Fig.. The rooed odel for VBR video ource. (3 (4 3. Preenaion of he Maheaical Model of Video Traffic in a Siulaion Prograe The iulaion odel coniing of VBR video raffic ource and ATM [] nework node wihou buffer wa creaed and ued in iulaion analyi. VBR Video Traffic Source Nuber of ATM Cell er Second oce ATM buniek/ekundu 5 45 4 35 3 25 2 5 ATM node 2 3 4 5 6 7 8 9 ouny richod ATM buniek Arrival of ATM Cell x 4 Fig. 2. The rooed odel of ATM node. Droed ATM Cell VP Bandwidh Variou VBR ource fro he required channel bandwidh, loe and link uilizaion oin of view are ued a inu o he ATM node. The ouu link ha he defined araeer a channel bandwidh (i.e. he nuber of bi ranferred er econd - bi/, cell lo requireen and link uilizaion. All hee araeer were e according o he requireen baed on he iulaion need. Video raffic generae inforaion ayload of ize 48 B, hen 5 B header i added. ATM node end ATM cell fro inu o he ouu link. ATM cell ha could no be accoodaed o he ouu VP due o exceeded caaciy will be lo. Paraeer a VP uilizaion and cell lo have been evaluaed in he iulaion according o he following equaion: VPuilizaion = cell _ lo = z 8 i= j=, j ax z 8 ( i, j axvp P i P i= j= VP 8 z 8 ( Pi, j ax VP i= j= z 8 P i= j=,(5 where z i he nuber of VBR ource, P i,j i he nuber of generaed cell fro ource i in ie j, ax VP rereen he axial nuber of ATM cell ha can be ranied z 8 o he ouu er one econd. P rereen he oal i, j i= j= nuber of ATM cell en by all VBR ource (each VBR video raffic ource generae 8 ATM cell baed on he araeer of a real video ource [] and (6
RADIOENGINEERING, VOL. 7, NO., APRIL 28 75 z 8 ( P i, j axvp i= j= rereen he oal nuber of he lo ATM cell. If P i,j < ax VP hen (P i,j - ax VP =. 4. Siulaion The ai of hi ar i o oberve an advanage of coon VP over earae VP for VBR video raffic ource. The obervaion i baed on he araeer for lo B, link uilizaion - ρ and channel bandwidh c [bi/]. For evaluaion wheher he earae or he coon VP i beer he araeer efficiency wa defined. Paraeer i defined a he raio of he oal required channel bandwidh for earae VP o he required channel bandwidh for coon VP. 4. M Searae VP wih an Equal Channel Bandwidh and Paraeer We have earae VP wih an equal channel bandwidh c a and cell lo requireen B. The ak i o calculae he required channel bandwidh by one coon VP - required for raniion of VBR video ource and calculaion of araeer. Paraeer will ay wha i beer - earae VP for each VBR ource earaely or one coon VP. The required channel bandwidh by coon VP i generaed by he iulaion baed on he given nuber of VBR video ource =,..., c a =52, 24 kbi/ and variou loe B. The araeer wa calculaed according o he equaion. ( * c a =. (7 c [kbi/] 52 2 873..7 3 26.45.26 4 552.26.3 5 882.98.36 6 22.3.39 7 2535.9.4 8 2859.88.43 9 38.27.44 35.39.46 Tab. 2. The calculaed araeer, for he given B =.9 %, c a = 52 kbi/ and ρ = 6.48 %. [kbi/].24 2.77.9 3 2.349.3 4 2.967.38 5 3.57.43 6 4.62.47 7 4.753.5 8 5.338.53 9 5.94.55 6.493.57 Tab. 3. The calculaed araeer, for he given B =.5 %, c a =,24 Mbi/ and ρ = 5.9 %. [kbi/] [kbi/] 52 2 85.6.27 3 86.28.4 4 349.59.5 5 64.4.59 6 858.39.65 7 23.46.7 8 2345.56.74 9 2585.2.78 2822.4.8 Tab.. The calculaed araeer, for he given B =.5 %, c a = 52 kbi/ and ρ = 4.76 %..24 2.824.2 3 2.599.8 4 3.364.2 5 4.2.24 6 4.87.26 7 5.69.27 8 6.366.28 9 7.9.29 7.852.3 Tab. 4. The calculaed araeer, for he given B =.69 %, c a =,24 Mbi/ and ρ = 7.82 %
76 E. CHROMÝ, I. BAROŇÁK, COMMON VIRTAL PATH AND ITS EXPEDIENCE FOR VBR VIDEO TRAFFIC.9.8.7.6.5.4.3.2. ca = 52 kbi/, B =.5 % ca = 24 kbi/, B =.5 % ca = 52 kbi/, B =.9 % ca = 24 kbi/, B =.69 % 2 3 4 5 6 7 8 9 Nuber of Traffic Source - Fig. 3. Relaion beween araeer and he nuber of VBR video ource. Fro Tab. - 4 and Fig. 3 i i obviou ha araeer for coon VP ha lower value han he oal required channel bandwidh for earae VP for he given nuber of ource. Wih he riing nuber of VBR video ource he ignificance of coon VP ue i riing. Paraeer ge lower value wih he riing channel bandwidh c a. On he conrary, araeer ge higher value wih ricer cell lo requireen. For illuraion, if =.7 (in cae for B=.5 %, c a = 52 kbi/ and =7 hen for raniion of even VBR ource hrough even earae VP he oal required channel bandwidh i by 7 % higher han he channel bandwidh required by coon VP for hee 7 video ource. 4.2 Two Searae VP wih an Equal Channel Bandwidh and Differen Requireen on Cell Lo and Paraeer We have wo earae VP wih an equal channel bandwidh c a, bu wih differen cell lo requireen B. The ak i o calculae he required channel bandwidh which i calculaed for he ricer araeer B. Paraeer will ay in which cae he coon VP will ill have juificaion. Reflecion are ade for c a = 52, 24 and 248 kbi/, bu wih differen cell lo requireen. Lo of earae VP B and B 2 are reened in Tab. 2. Paraeer will e for ricer lo araeer B (iniu fro B and B 2 and conequenly araeer i calculaed (alo final link uilizaion i calculaed for coon VP - ρ. Fro Tab. 5 and Fig. 4 we can clearly ee he exedience of coon VP baed on he araeer. The value of araeer grow in B B 2. In he cae of B < B 2 he cell lo araeer wa unchanged. Alo i i obviou ha coon VP ha higher juificaion in he cae of lower required channel bandwidh of earae VP. c a = 52 kbi/ B =.57 % ρ = 4.7 % c a = 24 kbi/ B =.5 % ρ = 5.93 % B 2 ρ 2 B [kbi/] ρ 6* -5 2.4 6* -5 98.2 34.47.2.5 3.6.5 84.79 43.42.2.57 4.7.57 83.9 5.86.27.285 5.8.57 873.86 53.48.7.2 6.5.57 945.52 55.2.8 3* -5 35.65 3* -5 798 49.32.3.3 45.33.3 752 56.53.6.5 5.5 79 6.3.9.4 6.5 837 62.45..27 75.4.5 23 64.6. c a = 5* - 248 5 49.67 5* -5 369 6.95.3 kbi/.2 58.58.2 3599 68.8.3 B =.6 %.6 6.62.6 3558 7.34.5 ρ =.7 73.73.6 3855 7.7.6 6.62 %.6 83.9.6 492 72.65. Tab. 5. Paraeer for wo earae VP wih he equal channel bandwidh and differen loe..25.2.5..5 ca = 52 kbi/ ca =.24 Mbi/ ca = 2.48 Mbi/.2.4.6.8.2 Lo - B Fig. 4. Paraeer for wo indeenden VP wih he ae channel bandwidh and variou cell loe. 5. Dicuion of Reul Baed on he coarion of he reul for earae and coon VP we can ay ha coon VP ha he greae juificaion in he cae of ulile VBR video ource: ha have he ae requireen for cell lo, heir requireen for channel bandwidh i all, VBR video ource have ric requireen on cell lo.
RADIOENGINEERING, VOL. 7, NO., APRIL 28 77 The higher nuber of VBR ource, he higher value of araeer, o we can ave a ignifican channel bandwidh. In he cae of ulile VBR video ource wih differen lo requireen i i aroriae o claify hee ource ino ulile clae (each cla will conain ource wih he equal lo requireen. Afer hen i i beer o ue coon VP fro channel bandwidh aving oin of view. There will be no ix of raffic ource wih differen lo requireen in one coon VP, o araeer will ge higher value han in he cae of one coon VP for all ource. We deonraed exedience of coon VP for variable bi rae raffic ue over earae VP fro ignifican channel bandwidh aving oin of view. ilizaion of coon VP can conribue o oal co aving for elecounicaion raffic. 6. Concluion There i a nuber of ioran area wihin he NGN (Nex Generaion Nework field ha draw aenion of elecounicaion reearcher and exer. I i ainly he iroveen of QoS (Qualiy of Service araeer, anageen ye, uliedialiy, rouing in NGN nework, nework dienioning, oiizaion of ye ar of NGN nework and any oher area. Thi aer deal wih nework dienioning. I how he advanage of ue of coon VP over earae VP for VBR video raffic ource. Verificaion i baed on he iulaion analyi in MATLAB environen by ue of aheaical odel of VBR raffic ource baed on Markov chain. Acknowledgeen Thi work i ar of reearch aciviie conduced a he Slovak Technical niveriy Brailava, Faculy of Elecrical Engineering and Inforaion Technology, Dearen of Telecounicaion, wihin he coe of he rojec VEGA No. /38/6 Traffic in convergen elecounicaion ye and nework. Reference [] Video Trace for Nework Perforance Evaluaion. Arizona Sae niveriy, h://race.ea.au.edu/raceain.hl [2] ROSE, O. Traffic Modeling of Variable Bi Rae MPEG Video and i Iac on ATM Nework. Bayeriche Juliu-Maxiilian- nveria Wurzburg, 997. [3] ALHERAISH, A. Auoregreive video conference odel. Inernaional Journal of Nework Manageen, Seeber, 24, vol. 4,. 329-337. [4] CSELÉNYI, I.., MOLNÁR, S. VBR video ource characerizaion and a racical hierarchical odel. Telecounicaion Sye, 2. [5] SARKAR,., RAMAKRISHNAN, S., SARKAR, D. Modeling fulllengh video uing Markov-odulaed gaa-baed fraework. IEEE/ACM Tranacion on Neworking (TON, 23, vol.,. 638-649. [6] L, Y. Q., PETR, D., FROST, V. Survey of Source Modeling Technique for ATM Nework. Technical Reor TISL-23-, niveriy of Kana, Seeber 993. [7] ZHANG, X., SHIN, K. Markov-chain odeling for ulica ignaling delay analyi. IEEE/ACM Tranacion on Neworking, Augu, 24, vol. 2,. 667-68. [8] LCANTONI, D., NETS, M., REIBMAN, A. Mehod for erforance evaluaion of VBR video raffic odel. IEEE/ACM Tranacion on Neworking, Aril, 994, vol. 2, no. 2,. 76-8. [9] BOLCH, G., GREINER, S., MEER, H., TRIVEDI, K. Queueing Nework and Markov Chain, Modeling and Perforance Evaluaion wih Couer Science Alicaion. Second Ediion, John Wiley & Son, Inc., Hoboken, New Jerey, 26, ISBN-: -47-56525-3. [] KAVACKÝ, M. Connecion adiion conrol ehod in ATM nework. In 7h Inernaional Conference Reearch in Telecounicaion Technology RTT 26. Brno (Czech Reublic, Seeber - 3, 26. Abou Auhor... Erik CHROMÝ wa born in Veľký Kríš, Slovakia, in 98. He received he engineering degree in elecounicaion in 25 fro he Faculy of Elecrical Engineering and Inforaion Technology, Slovak niveriy of Technology (FEI ST Brailava. In 27 he ubied PhD work fro he field of Obervaion of aiical roerie of inu flow of raffic ource on virual ah dienioning and hi cienific reearch i focued on oiizing of rocee in convergen nework. Ivan BAROŇÁK wa born in Žilina, Slovakia, in 955. He received he elecronic engineering degree fro he Slovak Technical niveriy Brailava in 98. Since 98 he ha been a lecurer a he Dearen of Telecounicaion ST Brailava. In 992 he ubied PhD work fro he field of Terinal elehone equien. In 995 he becae an aociae rofeor for he ubjec alied inforaion. Nowaday he work a a rofeor a he Dearen of Telecounicaion of FEI ST in Brailava. Scienifically, rofeionally and edagogically he focue on roble of digial wiching ye, ATM, Telecounicaion anageen (TMN, Nex Generaion Nework, roble of oial odeling of rivae elecounicaion nework and ervice.