Using Switched Beam Smart Antennas in Wireless Ad Hoc Networks with Angular MAC Protocol

Transcription

1 Uig Switchd Bam Smart Ata i Wirl Ad Hc Ntwrk with Agular MAC Prtcl Erdm Uluka, Özgür Gürbüz, Sabaci Uivrit, Facult f Egirig ad Natural Scic, Tuzla, 34956, Itabul, Turk rdmu@u.abaciuiv.du, gurbuz@abaciuiv.du Abtract I thi papr, a w mdium acc prtcl, Agular MAC (AN-MAC), i prpd fr hacig th prfrmac f Ad Hc Wirl Lcal Ara Ntwrk (WLAN) b th u f mart ata. I rdr t appl bam frmig with mart ata, th lcati f th rcivr d t b crrctl dtrmid. I thi papr, w ar prpig a Dircti Fidig (DF) algrithm thrugh which, tati xchag mdifid RTS/CTS mag fr traiig with ach thr t dtrmi thir rpctiv lcati ad at th am tim tablih th lik btw d. With th hlp f th agular RTS/CTS mag, a mdium acc tabl i ctructd t track th lcati f t l th dtiati d but al all cmmuicatig ighbr. With thi fatur, ur prtcl abl agular CSMA ad Spac Divii Multipl Acc. Th prtcl al u l dirctial bam t guarat rag xti. I thi papr, th prfrmac f th prtcl i valuatd ad cmpard with mi, rgular WLAN. I. INTRODUCTION Th d fr high qualit lik ad grat dmad high thrughput ha mtivatd w hacmt ad wrk i wirl cmmuicati uch a mart ata tm. Smart (adaptiv) ata abl patial ru ad th icra th cmmuicati rag bcau f th dirctivit f th ata. Hwvr th hacmt quatifid fr th phical lar ma t b fficitl utilizd, ul Thi wrk i upprtd b Cic Stm Uivrit Rarch Prgram th Mdia Acc Ctrl (MAC) lar i digd accrdigl. Uig dirctial ata i plac f mi dirctial ata itrduc m prblm uch a hidd trmial prblm ad th. daf f d. Th gal f th uig dirctial ata i t maximiz th prfrmac f th WLAN b icraig thrughput, rag ad Sigalt-Itrfrc-Plu-Ni Rati (SINR). Dirctial ata prvid a icra i radiatd pwr bcau f fcuig th tramittr pwr dircti. Thi imprv th rag f th tramittr. Th ata wrk rciprcal, ad fr thi ra, th rcivd pwr at th rcivr i al icrad. O th thr had, th dirctivit f th ata allw th d t cacl ifrrig igal arrivig at rcivr frm thr dircti. Uig dirctial ata fficitl rquir th kwldg f th xact lcati f cmmuicatig d. DMAC prtcl f Vaida [1] u dirctial RTS ad CTS mag t rrv th mdium tward th kw lcati f a d. I [1], Glbal Pitiig Stm (GPS) aumd fr fidig ur lcati. Hwvr, th GPS tm that u atllit cat b applid fr WLAN that ar mt f th tim dpld i idr virmt. I [2], Naipuri ad t.al. prpd t u a variati f RTS/CTS xchag i IEEE Thir prtcl i prpd fr igl bam dirctial ata, whr th lcati ifrmati i btaid b Dircti f Arrival Algrithm (DA). DA algrithm dpd lctig th ata which th maximum pwr ha b rcivd. Kraki ad t.al. hav prpd t tr th RTS bam ad d data i diffrt dircti qutiall [3]. Thi rquir m tim t 233

2 fiih trig ad tablih th lik. Durig th trig itrval, all d i th twrk rmai ilt ad th twrk capacit i watd. I additi, th xchagd RTS ad CTS mag i [3] d t ctai adquat fild t mak th d tart cmmuicati immdiatl aftr tart up. Dirctial ata ca icra th prbabilit f hidd trmial prblm ad th daf f th d. Durig th dirctial cmmuicati f tw d, thr uawar d ma attmpt t d mag t th cmmuicatig d. Sic th dtiati d cat rpl, packt will b lt aftr ma rtri. Vaida ad t.al. prpd t u TDMAC algrithm i [4] fr thi daf prblm. Th uggtd uig m prti f th frquc pctrum a a ctrl chal i th am bad f wirl lcal ara twrk t war th urrudig d. Surl, thi frc a w rgulati i th frquc bad f WLAN tm t implmt thir prpd prtcl. I thi papr, w ar prpig a w MAC prtcl, Agular MAC (AN-MAC) that iclud lcati fidig. Th tati xchag mdifid RTS/CTS mag, aml agular RTS/CTS, fr traiig with ach thr t dtrmi thir rpctiv lcati i a much fatr ad mr fficit wa tha [3]. With th hlp f th agular RTS/CTS mag, a mdium acc tabl i ctructd t track th lcati f t l th dtiati d but al all cmmuicatig ighbr. With thi fatur, ur prtcl abl agular CSMA ad Spac Divii Multipl Acc. I Agular MAC, th daf prblm i al addrd ad lvd i ur imulati. Fr valuatig ur prtcl, w mdld th MAC lar ad th actual IEEE b phical lar charactritic alg with ata ad ralitic wirl chal mdl. W cmpard Agular MAC with rgular IEEE prtcl with mi dirctial tramii. Th rult ar prmiig: W btaid a hacmt f up t 100% i vrall twrk thrughput. Th rt f th papr i arragd a fllw. Scti 2 prvid th dtail f Agular MAC icludig tati prprti, baic prtcl prati ad fram tp, ad pcial ca, SDMA upprt ad daf prblm. Scti 3 prt ur prfrmac valuati, icludig ata ad twrk mdl ad rult. Fiall cti 4 iclud ur cclui. II. THE PROPOSED PROTOCOL A. Stati Prprti I ur prtcl w ud a mdium acc tabl at ach d t kp lcati f ighbrig d. Our w tabl i a hw i Fig.1. M Addr Nighbr Addr M Bam Nighbr Bam Bam 0 Blckig Fild Maig M Addr : Wh am I? Nighbr Addr : Wh i i th rag f m? M Bam : M bt bam t cmmuicat with th ighbr i th lit. Nighbr bam : Nighbr bt ata t cmmuicat with m. Blckig : Which bam d I hav t blck? Fig.1.Th mdium acc tabl I IEEE , RTS ad CTS packt ar ud t war thr d abut th xt packt xchag btw d, t rrv th mdium fr a limitd tim. I ur prtcl, th packt ar ud t l t rrv th mdium but al t giv ifrmati abut th lcati f cmmuicatig d. A d lct it maximum pwr rcivd ata ad gt th packt vr it. Bcau f thi ra, w addd fw w fild t th packt. Fig.2.Tracivr architctur f th Agular MAC prtcl with 4 Ata. Bam 1 Bam 2 Bam 3 234

3 AN-RTS [3,A,B] B AN-RTS [2,A,B] C A AN-RTS [3,A,B] AN-RTS [0,A,B] AN-RTS [1,A,B] D Fig.3. Sampl tplg f d I ur wrk vr tati ha bam f 90 badwidth, which abl t cvr 360 b 4 ata. Stati ca mitr th igal lvl all bam, ad ch th bt. Th bt bam i dfid a th bam vr which a tati gt a igal with maximum SNR. W d 4 idividual RF chip ad 1 MAC chip i rdr t implmt th AN-MAC a hw i Fig.2. B. Baic Prtcl Oprati W dcrib th prtcl prati ad tp vr a xampl cari i Fig.3. Supp d A wat t tramit a data packt t d B i Fig.3. Nd A d th AN-RTS (Agular RTS) packt i vr dircti. Th frmat f thi packt i hw i Fig.4. I additi t xitig fild, AN-RTS packt ha a xtra Tramittr Bam Numbr fild (2 r 3 bit). Frm w, w will u th fllwig tati fr th AN_RTS fram: AN-RTS [urc bam, urc d, dtiati d]. Fram ctrl Durati Tramittr Bam Numbr Tramittr Addr Fig.4.AN-RTS Fram Frmat Rcivr Addr FCS Aftr gttig th AN-RTS packt that i t frm d A t d B ad radig it, vr urrudig d will b awar f packt xchag btw d A ad d B. Each tati rad th rcivr addr ad if a d i th dtiati, it mark th maximum pwr rcivd bam, which i i th dircti f urc d, t b ud at data xchag. Th d thr tha th dtiati d blck thir w bam at that dircti (igal dircti btaid frm rcivd bam a xplaid prviul) a t t b itrfrd b th data xchag btw d A ad d B, ad t t attmpt tramii, which ca cau itrfrc d A ad B. Whil blckig th bam, a timr i t aftr radig th durati fild f th rcivd AN-RTS packt. Thi wa calld Dirctial Ntwrk Allcati Vctr (D-NAV) i [1], which i i fact imilar t th NAV f but thi tim, fr a pcific dircti. Th bam ar rlad aftr thi timr xpir. 235

4 Aftr gttig th AN-RTS[3,A,B] packt, d B rcrd th am f th tati i it ighbr lit, th idx umbr f it rcivr bt bam (bam umbrd a 1 i Figur 3), which i t b ud durig cmmuicati btw th tw d. Nd B al dtrmi it bt bam i th dircti f d A, ad rcrd it i th apprpriat fild i it lit. Th bt bam i dfid a th bam vr which a tati gt a igal with maximum SNR. I thi ca, ic th dtiati i d B, itlf, it blck all th bam xcpt th bt bam (bam 1). Nw, lt u cidr d C i th am cari. Nd C gt th AN-RTS[3,A,B] packt, rad it ad rcrd d A it it ighbr lit whil tig bam umbr f d A udr ighbr bam fild ad it bt bam i th dircti f d A, which i th bam with bt rcpti with rpct t A. Nd C al mark t blckig fild at that dircti bcau at that mmt it i uawar f th lcati f d B. Aftr gttig th AN-CTS, d C will mark thi fild a t t itrfr with th data xchag. At th am tim with d C, d D gt thi am AN-RTS packt a fllw: AN-RTS [2,A,B]. It t th d A a th ighbr i th ighbr lit. Nd A bt bam i 3 that huld b ud whil cmmuicatig with d D. Nd D lct it bt bam a bam 2. It rad th dtiati ifrmati ad dtrmi that th dtiati i t itlf. Nd D d t blck a f it bam, bcau it i t ifrmd abut dtiati lcati. Nd D wait fr th CTS mag. O th thr had, thi d ma b far awa t har CTS mag ad it ma t gt th rquird ifrmati fr blckig th bam. It ca b ail that, if a d did t gt th CTS packt, it cat itrfr th cmmuicati: It ha t b a hidd d f d A. If d D tramit a igal i th dircti f d A, d A will rciv it frm th back id f blckd ata ad it will t b affctd b d D. Fig.5 hw th cfigurati f th tabl at ach d, aftr th AN-RTS packt i rcivd frm d A. Fram ctrl M Addr Nighbr Addr M Bam Nighbr Bam B A 1 3 C A 1 3 D A 2 0 Bam 0 Blckig Bam 1 Bam 2 Bam 3 Fig.5. Cmplt lit aftr gttig AN-RTS frm d A Durati Tramitti g Addr Rcivig Addr Tramittr Bam Numbr Tramittr Bt Bam Numbr Rcivr Bt Bam Numbr Fild Maig Durati : Durati f th cmmuicati Rcivig addr : Dtiati d f th packt Tramittr addr : Surc d f th packt Rcivr bt bam umbr : Rcivr will accpt packt vr thi bam Tramittr bam umbr : Th bam umbr f thi igal at urc d Numbr f m bt bam : Th d will cmmuicat vr thi bam Fig.6. AN-CTS Fram frmat Agular CTS (AN-CTS) i t i rp t AN- RTS. Fig.6 hw th packt ctt ad maig, i AN-CTS. Frm w w will u th tati: AN-CTS [urc d, dtiati d, bam umbr f thi igal, m bt bam, dtiati bt bam]. I additi t th xitig fild i IEEE CTS packt, AN-CTS packt ha tramittig addr, rcivr bt bam umbr, tramittr bam umbr, ad tramittr bt bam umbr fild. AN-CTS fram i t i all dircti, lik th AN- RTS fram (Figur 7). Aftr gttig th AN-CTS, d A fid ut that mdium i availabl fr cmmuicati. Hwvr thr d mut t itrfr with th cmmuicati btw A ad B, thrwi packt will cllid. Aftr gttig th AN-CTS vr it, d A ch it 3 rd bam, which i dirctd t d B, ad it d th data packt vr thi bam. FCS 236

5 AN-CTS [B,A,2,1,3] B AN-CTS [B,A,3,1,3] C AN-CTS [B,A,1,1,3] A AN-CTS [B,A,1,1,3] AN-CTS [B,A,0,1,3] D Fig.7. Rp f d B t AN-RTS with AN-CTS packt Wh d C gt th AN-CTS packt, it that d B 1 t bam i facig t it 3 rd bam. I th AN- CTS packt, th tramittr bt bam fild idicat that d t tr t tramit t d B vr thi bam, which i th 1 t bam f d B, thrwi packt will cllid. Thrfr d C blck it 3 rd bam. O th thr had, d C rad th rcivr bt bam fild ad dtct that d A will cmmuicat with d B vr it 3 rd bam. If d C wat t tramit a data packt t d A, it will lk at th mdium acc tabl ad that it 1 t bam i dirctd t d A 3 rd bam. If it tri t d a packt durig th cmmuicati btw d A ad d B, th packt will cllid. T prvt th cllii, d C blck it 1 t bam ad 3 rd bam a wll. It i l allwd t tramit vr bam 0 ad 2. Bam ta blckd fr th tim that i rad i th durati fild f rcivd packt. Nd C updat th tabl with thi ifrmati. Nd D will gt th AN-CTS packt vr it 2 d bam. It will chck th dtiati addr fild ad that th dtiati d i i it lit that i d A. A mtid bfr, d A will cmmuicat with B vr it 3 rd bam whr d D 2 d bam fac d A 0 th bam, which will b fr durig th cmmuicati bcau it i t facig t th bt bam f d A i th AN-CTS packt. O th thr had, if d D d a packt vr it 2 d bam, it will rach d B at bam umbr 0. Thi will t cau itrfrc d B. Figur 8 hw th rvid lcati tabl at ach d, aftr th AN-CTS fram. M Addr Nighbr Addr M Bam Nighbr Bam A B 3 1 B A 1 3 C A 1 3 C B 3 1 D A 2 0 D B 2 0 Bam 0 Blckig Bam 1 Bam 2 Bam 3 Fig.8. Cmplt lit aftr gttig AN-CTS frm d B 237

6 DATA[A,B] B C A ACK[A] ACK[D] DATA[D,C] D Fig.9. Achivig SDMA i th ampl cari Aftr agular AN-RTS/AN-CTS hadhak, d A will d th data vr it 3 rd bam t d B 1 t bam. Th dirctial data tramii will rduc th itrfrc ad tablih a rliabl ad high qualit chal btw cmmuicatig d. Durig th prati, w ma d ritati f th d. I [2] Naipuri uggtd t u a cmpa. W ca aum a imilar luti. C. SDMA upprt f th prtcl I th xampl cari i Figur 3, upp that d D wat t talk t d C, whil d A i cmmuicatig with d B. Nd hav blckd thir ata i dircti diffrt frm th dtiati d. Thrfr if th ata ad mdium ar availabl, a d ca cmmuicat with athr d withut itrfrig th gig tramii. Thi i calld patial Divii Multipl Acc (SDMA). Nd D d a w AN-RTS packt vr all ublckd bam. I thi cari, d D ha blckd ata. Nd C har thi A-RTS packt ad it will rpd with AN-CTS. Hwvr i th lit f d C, th blckig fild idicat that th 1t ad 3rd bam f d C ar blckd prviul ad it ca t d a packt vr th bam util th cmmuicati btw d A ad d B d. Hc, d C d a AN-CTS packt i all dircti xcpt d A ad d B. Nd C lct bam 0 a bt bam, blck th bam 2 ad updat th D-NAV f prviul blckd bam 1 ad 3 b th w NAV rad frm durati fild f AN-RTS packt t frm d D. Nd D gt th AN-CTS packt frm d C frm it 2d bam ad blck bam 0,1 ad 3. Aftr thi hadhak, d D d th data packt vr it 2d bam ad wait fr rcivig ACK frm d C (Figur 9). Th twrk thrughput i dubld whr tw data tram xit i th am baic tructur t f d imultaul. Spatial ru i achivd ad Spatial Divii Multipl Acc (SDMA) i pibl w. 238

7 D. Daf prblm Daf i th prblm f d that ar uawar f th cmmuicati f thr d with dirctial tramii. With th hlp f SDMA upprt, whil d A i cmmuicatig with d B, d C ad d D ca iitiat a w data xchag btw thm. Thr ar tw pibl cquc f thi: 1. If th lgth f data packt f d D i l tha th lgth f data packt that i tramittd frm d A, th data xchag btw C ad D will fiih bfr xchag btw A ad B, ad th d t t attmpt t tramit a w packt. Aftr xpirati f th D-NAV i ighbrig d ad NAV i cmmuicatig d, d will back-ff ad rctd fr th chal. B dig w AN-RTS packt i all dircti, th d that ar gig t cmmuicat will ifrm thr d fr th xt cmig data xchag. 2. If th lgth f data packt f d D i gratr tha th lgth f data packt that i tramittd frm d A, th data xchag btw C ad D will fiih aftr A ad B xchag. Hwvr bcau f th daf, d A ad d B i uawar f th cmmuicati btw C ad D, d A gt m pwr frm it 0 th bam ad d B gt m pwr frm it 0 th bam, which i tramittd frm th 2 d bam f d D. Thi d pwr i bcau f harig data packt i th m prti f it. Hwvr, th dumm bit giv ifrmati t d A ad d B. Sic th ar uig CSMA/CA algrithm, th ca thi igal ad dfr thir cmmuicati durig th gig cmmuicati btw d C ad d D withut dcdig r udrtadig it. Aftr fiihig th rcivig f dumm bit, th d will wait m amut f tim (SIFS+ACK_DURATION+DIFS) t prtct ACK f d D that i dtid t d C. Bcau f thi th will t mak cllii at d D. Nd A ad d B th rchck th mdium. Cidr th ca th data i t b tramittd frm d C, althugh d A & B th mdium, bcau f th dirctial tramii, th will bth b uawar f th gig cmmuicati btw C ad D. At thi tim, if d A wat t tramit a w data packt, it will d a w AN-RTS packt i all dircti bcau it did t blck a f it bam. Sdig a igal frm th 0 th bam f d A will itrfr th d D 2 d bam bcau it i rcivig th data packt vr it. If th igal i pwrful, th packt will cllid ad tha d D will wat t rtramit th am data packt, which will dgrad th vrall prfrmac f th twrk. E. Sluti t daf prblm Bcau f th daf prblm, th prfrmac f th mdium acc prtcl that ar digd t wrk with dirctial ata ar limitd t m cari. Hwvr, b th additi f w prcauti i ur prtcl, th prblm ca b prvtd. If a ur (lik d C) wat t d a data packt durig cmmuicati f thr (A ad B) ad if it kw A t B cmmuicati, it will calculat th rquird tim t iitiat a w tramii ad data xchag f it w. Th it will cmpar th rmaiig tim f D-NAV durati ad rquird tim t tramit a data fram. If it i ugh t cmplt th data xchag i thi rmaiig tim, it will d a AN-RTS packt vr it ublckd ata. Dubtl, d C will fiih tramii bfr A t B cmmuicati, d A ad B will t itrfr th gig tramii btw C ad D. Th all d will r-ctd fr th chal. If th calculatd tim i gratr tha th rmaiig tim, d C ma wait fr th cmplti f th A t B cmmuicati ad th it will ctd fr th chal. If th back-ff f d C i mallr tha d A, d C will gai th chal ad will tart it tramii. Thi will dcra xpctd twrk capacit with th u f dirctial ata ad giv th am prfrmac f mi dirctial tm f currt WLAN. 239

8 B A C D imulati virmt abl digr t crat ralitic wirl cari. DATA ACK DEFER WAIT Dumm bit AN-CTS ACK AN-RTS DATA Fig.10. Nd C war d A bcau f it gig tramii Nd C ma ifrm A ad B b athr impl mthd. Aftr th cmplti f A t B cmmuicati, D-NAV i d C will xpir. At thi tim d C will p all blckd ata ad d pwr frm th ata, t (Figur 10). Ol dig th rmaiig part f th data packt vr all ata via RF witch ca ail d thi. B thi wa, th urrudig d will b awar f th gig tramii. Th d l gt dumm bit but thi will mak thm t dfr thir tramii bcau f carrir ig mchaim ad wait fr ACK_DURATION + SIFS tim t prtct ACK. At th d f cmmuicati btw C ad D, all d will back-ff ad r-ctd fr th chal. I thi wrk, w hav mdifid th phical lar mdl t mak it t wrk with 4 idividual ata. W hav ud prdfid ad fixd bam ad cratd a ata pitr mdl. Th rcivd pwr f a igal ca b calculatd a a fucti f ma factr, icludig dircti vctr btw tw radi ata, ad th ata gai f ach ata alg that dircti vctr. Th ata gai pattr pcifid i th Ata Pattr Editr i ud t prvid th gai valu. Th fur ata i th mdl cvr fur diffrt dircti (Nrth-Eat, Nrth-Wt, Suth-Eat, Suth-Wt). Th ata pattr, which ar cratd b th pattr ditr, hav 10 dbi dirctial gai with 90 badwidth ad 20 db f frt t back rati. W al mdifid th MAC mdl t implmt ur w MAC prtcl ad t prvid all car itrfac with th ata mdl. Th digd mdl i hw i Figur 11. III. PERFORMANCE ANALYSIS A. Smart Ata ad Ntwrk Mdl I ur imulati w hav ud Optimum Ntwrk Simulati Tl (OPNET) [5]. OPNET imulati ar vt-driv. Th WLAN mdl wa digd t imulat MAC ad b phical lar. Th currt mdl u a itrpic ata fr midirctial tramii. Th wirl cmmuicati chal i mdld b 13 pipli tag icludig ata gai, prpagati dla, igal-t-i rati, calculati f backgrud i ad itrfrc i, tramii dla, tc. Thi pwrful Fig.11.OPNET Mdl f th Agular MAC prtcl with 4 Ata attachd t it B. Rult I ur imulati w hav ud charactritic f IEEE b tadard [6]. Th packt iz i ch a 1450 bt. Packt ar gratd radml with a itrarrival tim, xptiall ditributd with ma Th traffic lad i t that all d alwa hav data i thir buffr. 240

9 Firt, w hav imulatd th ampl cari rfrrd i cti 2. Th tplg a grid i hw i Figur 12. Nd A i tramittig t d B; d D i tramittig t d C. B C A D Fig.12. Sampl tplg xamid bfr Th Figur 13 hw th thrughput valu fr vrall twrk ad pr d i mi dirctial tm wh uig th tplg hw i Figur 12. Avrag thrughput i plttd agait tim. Th tp curv dpict vrall twrk thrughput, th cd ad third curv hw thrughput maurd frm d B ad d C, rpctivl. Fig.14. Thrughput f d B ad C whil uig AN- MAC I mi tramii vr d i th am baic rvic t ha t wait fr thr t fiih thir cmmuicati. I ur AN-MAC prtcl, th bfit f dirctial tramii ar xplitd, ad th d ar abld t u th am chal imultaul. Nxt, w cidr a mr cmplicatd cari (Figur 15). Nd A i tramittig t d B; d D i tramittig t d C; d E i tramittig t d F. B C Fig.13. Thrughput f d B ad C whil uig mi MAC I Figur 14, w hwd th rult f Agular MAC prtcl. Agai, ttal ad pr d thrughput valu ar plttd agait tim. It ca b that, AN-MAC imprvd th ttal thrughput f th rigial mi tm, b 60% fr thi tplg. SDMA i achivd. A Fig.15. Thr imultau tramii ca xit i thi tplg D E F 241

10 imprvd th ttal thrughput f rigial mi tm, b almt 100% fr thi tplg. Bcau SDMA i achivd, w xamid a icra i twrk thrughput. It i imprtat t t that, th imprvmt i th thrughput pr d dpd th lcati f th ur. Th dirctial tramii abld igificat imprvmt i th vrall twrk capacit. IV. CONCLUSIONS Fig.16. Thrughput f d B, C ad F whil uig mi MAC Th Figur 16 hw th thrughput valu fr vrall twrk ad pr d i mi dirctial tm wh uig th tplg hw i Figur 15. Avrag thrughput i plttd agait tim. Th tp curv dpict vrall twrk thrughput, th cd, third ad furth curv hw thrughput maurd frm d F, d B ad d C, rpctivl. Fig.17. Thrughput f d B, C ad F whil uig AN- MAC I thi papr, w hav prpd a w MAC prtcl, Agular MAC that iclud lcati fidig. Th tati xchag mdifid RTS/CTS mag, which ar t i all dircti t war thr d. Agular RTS/CTS mag ar ud t ctruct a mdium acc tabl t track th lcati f t l th dtiati d but al all cmmuicatig ighbr. With thi fatur, ur prtcl prvid fficit acc with dirctial ata b ablig agular CSMA ad SDMA. Athr advatag i that th immuit f th twrk i imprvd agait thr urc f itrfrc (Blutth ad thr dvic i th am bad) ad i. W valuatd th prfrmac f AN-MAC agait rgular mi tati via imulati. I additi t mdlig th MAC lar, w mdld ata charactritic ad th wirl chal i dtail that itrfrc cari ar rflctd accuratl. Our imulati idicat igificat hacmt vr mi Al, a hw b imulati, th daf prblm i wirl twrk i addrd ad lvd b Agular MAC. Our rult far hw up t 100% imprvmt vr mi thrughput. Th rult w btaid ar prmiig; hwvr th xtt f thi prfrmac imprvmt dpd th twrk tplg. W itd t xtd ur prfrmac aali t iclud mr diffrt tplgi ad cari. W vii that th AN-MAC prtcl will b mt apprpriat fr wirl bridg itrcctig twrk f buildig, ic xtra ata dplmt ad multipl tracivr wuld b affrdabl. I Figur 17, w hwd th rult f Agular MAC prtcl. Agai, ttal ad pr d thrughput valu ar plttd agait tim. It ca b that, AN-MAC 242

11 REFERENCES [1] Yug-Ba K; Shakarkumar, V.; Vaida, N.H.; Mdium acc ctrl prtcl uig dirctial ata i ad hc twrk INFOCOM Nitth Aual Jit Cfrc f th IEEE Cmputr ad Cmmuicati Sciti. Prcdig. IEEE, Vlum: 1, March 2000 Pag:13-21 vl.1 [2] A. Naipuri, S. Y, J. Yu, R.E. Hirmt, A MAC prtcl fr mbil ad-hc twrk uig dirctial ata, I Prcdig f IEEE Wirl Cmmuicati ad Ntwrkig Cfrc (WCNC), Chicag, IL, Sp [3] R.R. Chudhur, X. Yag, R. Ramaatha, N. H. Vaida Uig Dirctial Ata fr Mdium Acc Ctrl i Ad Hc Ntwrk, ACM MbiCm 2002, Sptmbr [4] T. Kraki, G. Jakllari, ad L. Taiula, A MAC prtcl fr full xplitati f dirctial ata i ad hc wirl twrk, i Prcdig f Mbihc, [5] OPNET Tchlgi, IcTM. Optimum Ntwrk Simulati ad Egirig Tl, [6] IEEE Stadard Dpartmt. Wirl LAN mdium acc ctrl (MAC) ad phical lar (PHY) pcificati, IEEE tadard ,