IMPROVISED CHANNEL ASSIGNMENT TECHNIQUE FOR WIRELESS NETWORK USING GENETIC ALGORITHM

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1 Avbe Onne t Internton Journ of Computer Scence nd Mobe Computng A Monthy Journ of Computer Scence nd Informton Technoogy IJCSMC, Vo. 3, Issue. 10, October 2014, pg RESEARCH ARTICLE ISSN X IMPROVISED CHANNEL ASSIGNMENT TECHNIQUE FOR WIRELESS NETWORK USING GENETIC ALGORITHM 1 Gunjn Lvny, 2 Dheerj Khtr 1 Reserch Schor, 2 Assstnt Professor Deprtment of Eectroncs nd Communcton Engneerng, South Ponts Insttute of Engneerng & Technoogy, Sonpt, Hryn (Ind) Abstrct: Wreess technoogy deveopment s bscy becuse of trnsformton of wht hs been rgey medum for supportng voce teephony nto medum for supportng other servces, such s the trnsmsson of vdeo, mges, text, nd dt. Thus, the demnd for new wreess cpcty s growng t very rpd pce. Athough there re, of course, st gret mny technc probems to be soved n wrene communctons. The trdton resources tht hve been used to dd cpcty to wreess systems re rdo bndwdth nd trnsmtter power. Unfortuntey, these two resources re mong the most severey mted n the depoyment of modern wreess networs: rdo bndwdth becuse of the very tght stuton wth regrd to usefu rdo spectrum, nd trnsmtter power becuse mobe nd other portbe servces requre the use of bttery power, whch s mted. These two resources re smpy not growng or mprovng t rtes tht cn support ntcpted demnds for wreess cpcty. For effcent utzton of the rdo spectrum, frequency reuse scheme tht s consstent wth the objectves of ncresng cpcty nd mnmzng nterference s requred. Aocton of chnnes to ceur system s mportnt from performnce pont of vew. The octon of set of chnnes to ech bse stton durng the pnnng process.e. Frequency Pnnng Process s NP-compete optmzton probem wth constrnts for whch dfferent pproched hve been proposed. Exmpes: Vrous ttempts v grph coorng gorthms, neur networs, set theory nd other methods v smuted nneng gorthms hve been proposed to sove ths probem. However, ths pper s to sove the chnne ssgnment probem n wreess networ usng Genetc Agorthm. The gener purpose Smpe Genetc Agorthm hs been proved to cope up wth vred chnne demnds n dfferent wreess networs. Key Words: Genetc Agorthm (GA), Fxed Chnne Assgnment (FCA) Bse Stton (BS), Swtchng Center (MSC), Dynmc Chnne Assgnment (DCA), Spce Dvson Mutpexng (SDM) 2014, IJCSMC A Rghts Reserved 932

2 1. Introducton We propose Serch Technque bsed on evouton nd survv smr to found n nture [1] [2] s beng used to ddress the chnne ssgnment probem (CAP) n ceur systems. A smpe genetc gorthm s beng exmned whch mes use of oc serch gorthm s mutton operton whch shows of budng cpbe fesbe chnne ssgnment for dfferent system scenros s we s dfferent trffc ods. 1.1 The Chnne Assgnment Probem Let us consder N hexgon ces ech hvng one bse stton t the center trnsmttng wth n omn-drecton ntenn cpbe of tunng on ny of the C vbe chnnes beed s c ( =1, 2... C). Moreover, the nterference between ny pr of ces s ssumed to be nown so tht the frequency seprton constrnts my be estmted n order to vod co-chnne nd djcent chnne nterference. Such nterference constrnts re represented by n nterference mtrx X of the form: Where eements xj (,j = 1, 2, N) represent the frequency seprton requred between chnnes ssgned to ces nd j respectvey necessry to mntn nterference beow certn threshod. Usng ths mtrx t s possbe to represent co-chnne nd djcent chnne nterference constrnts by choosng pproprted vues for entres xj. In ths wor we w consder the co-chnne nterference cse where eements n X re gven by: xj ={ 1: f ce nd ce j cnnot reuse chnne 0: otherwse We refer to bove requrements s hrd nterference requrements s they re consdered to be nvobe. However soft constrnts cn so be desrbe such s to reserve some chnnes for future networ growth or hnd-off purposes or to mntn n redy predefned chnne ssgnment the sme s possbe. Therefore t my be desrbe to perform chnne ssgnment by tryng to use the est number of chnnes or on the other hnd, to produce the mnmum number of chnne ressgnments. In order to perform chnne ssgnment t s necessry to now the number of chnnes requred n ech ce. Let λ be the c rrv rte t ce nd µ the men c hodng tme for cs. Then Erng-B formu permts to determne the number t of chnnes demnded t ce necessry to proportonte grde of servce equ to P b. Let T be chnne demnd vector wth eements t (= 1, 2,.., N ) representng the number of requred chnnes t ce. The chnne ssgnment probem s then defned s: Gven C chnnes nd N ces ech requrng t chnnes, fnd the optm [NxC ] chnne ssgnment mtrx A gven by: 2014, IJCSMC A Rghts Reserved 933

3 Wth eements: = { 1 : f ce s ssgned chnne c 0 : otherwse A chnne ssgnment s dmssbe f both trffc nd nterference constrnts re fufed. Ths mpes tht: C 1 t For I nd j f c nd c re two chnnes ssgned to ce I nd ce j, Then C - c n 2. The Smpe Genetc Agorthm The gorthm s bsed upon codng soutons s bnry strngs. Usng ths codng scheme ows us to drecty represent the chnne ssgnment mtrx A by pcng rows n snge strng [3], [4]. Then strng s ctuy formed by conctentng N substrngs of ength C representng chnnes n ces. The ftness functon used to evute the ndvdus n ths gorthm s: N C 2 N C N C F t j1 1 j x j j.(1) Where the frst term s the number of confcts produced for ssgnng dfferent rther thn the requred number of chnnes t ech ce wheres the second term s the number of confcts produced for nterference constrnt votons. The ftness functon defned n such wy mes the genetc gorthm to oo for soutons wth zero confcts; ths s, wth zero trffc nd nterference votons. The souton s serch s crred out usng the tournment seecton mechnsm whch conssts n choosng the best ndvdu between two rndomy pced from the poputon. Aso crossover opertor s empoyed n the serch process. The crossover opertor used s the - pont crossover whch operton conssts n seectng rndom strng poston of two strngs (ced prents) nd then budng up two new strngs wth probbty Pc (off- sprngs) by usng one prt of ech prent. The mutton opertor pped over every bt chnges the bt vue by ts compement wth probbty Pm. Athough the scope of ths gorthm s qute gener, t s shown tht t s very usefu n fndng fesbe frequency ssgnments for some scenros of ceur system. In ths pper we hve used the Genetc Agorthm nd Drect Serch Toobox whch s coecton of functons tht extend the cpbtes of the Optmzton Toobox nd the MATLAB numerc computng envronment. The Genetc Agorthm nd Drect Serch Toobox ncudes routnes for sovng optmzton probems usng Genetc gorthm Drect serch These gorthms enbe us to sove vrety of optmzton probems tht e outsde the scope of the stndrd Optmzton Toobox. A the toobox functons re MATLAB M-fes, mde up of MATLAB sttements tht mpement speczed optmzton gorthms. We cn extend the cpbtes of the Genetc Agorthm nd Drect Serch Toobox by wrtng our own M-fes, or by usng the wrtng M-Fes for Functons we wnt to optmze. To use the Genetc Agorthm nd Drect Serch Toobox, we frst wrte n M-fe tht computes the functon we wnt to optmze. The M-fe ccept row vector, whose ength s the number of ndependent vrbes for the objectve functon, nd return scr. Ths code wrtten for ths re vbe wth uthors. 3. Unform nd Non-Unform Condton 3.1 Unform Trffc Condton In ths we ssume tht the trffc condton s unform n the ces. Let we consder 6 chnnes n ech ces. We consder hexgon structure of ces s shown n the fg.1. suppose there re 20 ces nd we hve tot of 50 chnnes. Aso we consder reuse dstnce equ to 2, nd then the nterference mtrx, X for ths structure s gven by [20x20] mtrx. 2014, IJCSMC A Rghts Reserved 934

4 Fg. 1 Ceur Structure Ce Fg. 2 Interference Mtrx As from the fgure 1 whch s obtned from genetc gorthm, the number of confcts produced for ssgnng dfferent rther thn the requred number of chnnes t ech ce nd the number of confcts produced for nterference constrnt votons re 2 fter 700 generton. For 500 generton we obtn tot of 18 errors for the sme condtons s shown n fg. 2. We obtn the chnne ssgnment mtrx A s gven beow. Fg. 3 Resuts of GA 2014, IJCSMC A Rghts Reserved 935

5 Ce Chnne Fg. 4 Assgned Chnnes 2014, IJCSMC A Rghts Reserved 936

6 3.2 Non-unform Trffc Condton Fg.5 Percentge of fufment In ths we ssume tht the trffc condton s not unform n the ces. Let we consder t= [ ] for the th ces. We consder hexgon structure of ces s shown n the fg.. whch conssts of 20 ces nd we hve tot of 30 chnnes. Then we fnd A Mtrx s gven beow: Ces Chnnes Fg. 6 Assgned Chnnes 2014, IJCSMC A Rghts Reserved 937

7 2014, IJCSMC A Rghts Reserved 938 As we cn see tht tot number of nterference, n the non-unform cse, s 66 fter 700 generton. We cn now chec our resut for dfferent trffc condtons. In other, for dfferent trffc condton n whch we got the number of confcts equ to 30. () (b) Fg. 7 Resuts of GA Fg. 8 Percentge of Fufment 4. Chnne Assgnment usng Modfed Ftness Functon In the prevous ftness functon djcent chnne nterference s not consdered nd so t counts ony the number of terms by whch demnd s not fufed nd the co-chnne nterference [5,6,7,8,9]. So here modfed ftness functon s used whch so counts the djcent chnne nterference. The modfed ftness functon s gven by: D where D x t F N C C N C N j j C j j N C ) *( * * * ) ( 1 1 1,, ,,, 1 2 1,

8 Where the frst term s the number of confcts produced for ssgnng dfferent rther thn the requred number of chnnes t ech ce wheres the second term s the number of confcts produced due to co- chnne nterference constrnts voton nd the thrd term counts djcent chnne nterference constrnts voton Fg. 9 Ceur Structure Consdered 4.1 Unform Condton 6-Chnne n Ech Ce () Fg. 10 Resuts of GA (b) 2014, IJCSMC A Rghts Reserved 939

9 Fg. 11 Percentge of Fufment 4.2 Unform Condton (7-Chnnes n Ech Ce) Ce Numbers Assgned Chnnes , IJCSMC A Rghts Reserved 940

10 Fg. 12 Assgned Chnnes () (b) Fg. 13 Resuts of GA Fg.14 Percentge of Fufment 4.3 Nonunform Condton Ce Numbers Demnd Assgned Chnnes , IJCSMC A Rghts Reserved 941

11 Fg.15 Assgned Chnnes () (b) Fg. 16 Resuts of GA Fg. 17 Percentge of Fufment 2014, IJCSMC A Rghts Reserved 942

12 5. Concuson In the proposed wor we re med to compment the trdton chnne octon method nd Genetc Agorthm pproch s used to sove the chnne ssgnment probem n ceur teecommuncton systems. Fxed chnne ssgnment usng genetc gorthm s deveoped n whch more number of ces nd ess number of chnnes s ten nd ssgnment s done n such wy tht we obtn mxmum chnne utzton. We, so deveop gorthm, n whch we use Genetc Agorthm, to octe the chnnes to the ces whch tes very ess number of chnnes nd octe them for more number of ces. Modfed functon s better s compred to prevous one. In ths reserch pper we hve ten chnne ssgnment for both unform nd non-unform chnnes. REFERENCES: [1]. F. J. Jmes-Romero nd D. Munoz-Rodrguez, Chnne Assgnment n Ceur Systems Usng Genetc Agorthms, n Process IEEE Vehcur Technoogy Conference, 1996 [2]. A. Yener nd C. Rose, Genetc Agorthm Apped to Ceur C Admsson: Loc Poces, IEEE Trnscton on Vehcur Technoogy, Vo. 46, Feb [3]. D. Becmnn, U. Kt, A New Strtegy for the Appcton of Genetc Agorthms to the Chnne Assgnment Probem, IEEE Trnscton on Vehcur Technoogy, Vo. 48, no.4, Juy 1999 [4]. G. Chrborty nd B. Chrborty, A genetc Agorthm Approch to Sve Chnne Assgnment Probem n Ceur Rdo Networs, Proc IEEE Mdnght-Sun Worshop on Soft Computng Methods n Industr Appcton, pp , 1999 [5]. Sefpour N, A GA Bsed Agorthm wth Very Fst Rte of Convergence, Internton Conference on Computton Integence, Germny, 2001 [6]. G. Chrborty, An Effcent Heurstc Agorthm for Chnne Assgnment Probem n Ceur Rdo Networs, IEEE Trnscton on Vehcur Technoogy, Vo. 50, no. 6, pp , Nov [7]. Sefpour N, A GA Bsed Agorthm wth Very Fst Rte of Convergence, Internton Conference on Computton Integence, Germny, 2001 [8]. S. Srr nd K.N. Svrjn, Chnne Assgnment Agorthm Stsfyng Co-Chnne nd Adjcent Chnne Constrnts n Ceur Mobe Networs, IEEE Trnscton on Vehcur Technoogy, Vo. 51, pp , 2002 [9]. S. C. Ghosh, B. P. Snh nd N. Ds, Chnne Assgnment usng Genetc Agorthm Bsed on Geometry Symmetry, IEEE Trnscton on Vehcur Technoogy, Vo. 52, pp , , IJCSMC A Rghts Reserved 943