Research Article Game Theoretic Modeling of NGANs: Impact of Retail and Wholesale Services Price Variation

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1 Intrnational Scholarly Rsarch Ntwork ISRN Communications and Ntworking Volum 22, Articl ID 746, 9 pags doi:.542/22/746 Rsarch Articl Gam Thortic Modling of NGANs: Impact of Rtail and Wholsal Srvics Pric Variation João Paulo R. Prira and Pdro Frrira 2 School of Tchnology and Managmnt, Polytchnic Institut of Bragança (IPB), Bragança, Portugal 2 Institut for Systms and Robotics, Tchnical Univrsity of Lisbon (IST), 49- Lisbon, Portugal Corrspondnc should b addrssd to João Paulo R. Prira, jprp@ipb.pt Rcivd 2 Fbruary 22; Accptd 8 April 22 Acadmic Editors: L. Pavl and R. Szabo Copyright 22 J. P. R. Prira and P. Frrira. This is an opn accss articl distributd undr th Crativ Commons Attribution Licns, which prmits unrstrictd us, distribution, and rproduction in any mdium, providd th original work is proprly citd. Th incrasing dmand for broadband accss lads oprators to upgrad th xisting accss infrastructurs (or building nw accss ntwork). Broadband accss ntworks rquir highr invstmnts (spcially passiv infrastructurs such as trnchs/ducts and bas station towrs/masts), and bfor making any dcision it is important to analyz all solutions. Th slction of th bst solution rquirs undrstanding th tchnical possibilitis and limitations of th diffrnt accss tchnologis, as wll as undrstanding th costs of building and oprating th ntworks. This study analyzs th ffct of asymmtric rtail and wholsal prics on oprators NPV, profit, consumr surplus, wlfar, rtail markt, wholsal markt, and so on. For that, w propos a tchnoconomic modl complmntd by a thortic-gam modl. This tool idntifis all th ssntial costs of building (and oprating) accss ntworks and prforms a dtaild analysis and comparison of th diffrnt solutions in various scnarios. Communitis, oprators/srvic providrs, and rgulators can us this tool to compar diffrnt tchnological solutions, forcast dploymnt costs, compar diffrnt scnarios, and so on, and hlp thm in making dploymnt (or rgulatory) dcisions. Th gam-thory analyss giv a bttr undrstanding of th comptition and its ffct on th businss cas scnarios conomic rsults.. Introduction Srvic providrs, ntwork oprators, and Intrnt accss providrs ar facd with th challng of providing highrcapacity accss to th nd usr and offring widr srvics []. Consquntly, nw Intrnt infrastructur and tchnologis that ar capabl of providing high-spd and highquality srvics ar ndd to accommodat multimdia applications with divrs quality of srvic (QoS) rquirmnts. Until a fw yars ago, Intrnt accss for rsidntial usrs was almost xclusivly providd via public switchd tlphon ntworks (PSTN) ovr th twistd coppr pair [2]. Th nw quadrupl play srvics (i.., voic, vido, data, and mobility), which rquir high-spd broadband accss, cratd nw challngs for th modrn broadband wirlss/ wird accss ntworks [3]. Th nw srvics ld to both th dvlopmnt of svral diffrnt last-mil solutions to mak th accss ntwork capabl of supporting th rquirmnts and a strongr intgration of optical and wirlss accss ntworks. Th mov toward nxt-gnration ntworks (NGNs) has significant implications for th tchnical architctur and dsign of accss ntwork infrastructur, as wll as th valu chains and businss modls of lctronic communications srvic provision [4]. This migration has bgun to transform th tlcommunication sctor from distinct singl-srvic markts into convrging markts [5]. NGNs allow consumrs to choos btwn diffrnt accss ntwork tchnologis to accss thir srvic nvironmnt. In our work, th NGN architctur will b limitd to th dvlopmnts of ntwork architcturs in th accss ntwork (local loop), rfrrd to as th nxt-gnration accss ntwork (NGAN). Although th cost of bandwidth in th activ layr has rducd significantly (and continually) in rcnt yars, th cost of civil works (such as digging and trnching) rprsnts a major barrir for oprators to dploy NGA infrastructur. Studis and dploymnts [7] show that civil infrastructur is th largst proportion of th costs of fixd accss dploymnt (up to 8%). Duct is a critical part of th nxt-gnration accss ntworks, and its sharing would

2 2 ISRN Communications and Ntworking Layr 3 Srvics Tabl : Avrag lngths assumptions. Layr 2 Layr Tchnology Cabls Ducts Activ infrastructur Infrastructur Passiv infrastructur Sgmnt Rgion (urban) Rgion 2 (rural) Fdr 7 m m Distribution 3 m 7 m Drop 5 m 25 m Figur : Ntwork layrs [6]. rduc or liminat this capital cost and barrir to ntry. Howvr, duct accss may nd to b complmntd by xtra civil work to incras infrastructur capacity, th us of dark fibr (whr availabl), or th us of conduits of altrnativ infrastructur providrs. This also highlights that diffrnt and/or complmntary rgulatory tools may b rquird in diffrnt parts of th ntwork [8]. 2. Effcts of NGNs on Markt Dfinition Th ntry of nw comptitors can b basd on th rsal of srvics from th incumbnt, on building up thir own infrastructurs, on rnting unbundld infrastructur from incumbnts, or on th combination of th abov lmnts. Th availability of ths options to comptitors and pric dfinition ar gnrally dtrmind by rgulatory policis [9]. So, th introduction of NGNs by tlcommunication ntwork oprators obligats th national rgulators to adapt thir accss rgulation rgims to th nw tchnological conditions. Rgulation and/or promotion of comptition by rgulatory masurs nd to b analyzd and compard. Th accss ntwork is usually th most xpnsiv componnt in trms of capital invstmnt (spcifically passiv infrastructur) and OA&M costs. Of th svral costs, civil nginring costs ar gratst whn it is ncssary to run a nw fibr or coppr connction to th cabint, building, or hom. Morovr, accss to xisting infrastructur, such as th ducts of th incumbnt or othr markt playrs or swag pips, is critically important to avoid digging. For [6], a local loop ntwork can b dividd into thr main layrs or sgmnts: a srvic layr and two infrastructur layrs (s Figur ). Layr includs passiv infrastructurs, such ducts and cabls, and rquirs th gratst invstmnt. Layr 2 consists of activ infrastructurs, such as th tchnical installations at th nd of th fibrs that snd, rciv, and manag th optical signals. Layr 3 includs svral srvics that consumrs buy from tlcommunication oprators. 3. Businss Cas Dfinition Th dfinition of a businss cas implis a grat numbr of assumptions, such as th pntration rat, componnts prics, and th markt shar rat. Howvr, it is difficult to gt an xact forcast of its prformanc. Th utility of a businss cas is to offr a mor approximatd stimation that allows th construction of scnarios for th futur. A businss cas should b as ralistic as possibl in ordr to b usful and Srvic profils Tabl 2: Srvic profil charactristics: rtail prics. On-tim activation fs (Connction) Expctd tariff volution (%) Monthly subscription fs Expctd tariff volution (%) Srv. C % 2C/month 5% Srv. 2 C % C/month 8% rflct all th variabls of intrst of th markt, as wll as thir volution and xpctd bhavior []. 3.. Trritory and Dmography. Th gographical aras considrd ar an ara with high population dnsity and an ara with low population dnsity and high covrag. For th rural ara, th roll-out stratgy dos not covr th whol ara (73 km 2 ) th targt ara is limitd to 34.4 km 2 with 23, inhabitants (s Tabl ). In our modl, w considr th last yars to stimat th avrag rat of incras:.62% for th urban ara and valu of.% for rural targt ara. Th population dnsity in th urban ara is 3,748 inhabitants pr squar kilomtr and 675 in th rural ara. Paramtrs prsntd in Tabl ar important to calculat th cost of trnchs/ducts, which ar th most significant proportion of th costs of fixd-accss dploymnt. Svral studis and modls [ 3] assum that, in urban aras, th duct availability rat is about 6% for fdr sgmnts and 4% for th distribution sgmnt. In rural aras, th duct availability rat is 25% for fdr and % for th distribution ntwork. Th rport from [4] assums that a substantial proportion (8% nar to th CO and 3% narr to th prmiss) of xisting ducts can b rusd for fibr dploymnt [5] Srvic Profil Assumptions. In this businss cas, w dfin two diffrnt srvics: slow Intrnt browsing srvic with downstram throughput of 2 Mbps and tripl play srvic with 2 Mbps of downstram rat. Th xpctd tariff volution (th factor by which th tariff is xpctd to incras or dcras annually) is dfind for both tariffs: connction and monthly f (s Tabl 2). Th assumptions prsntd ar basd on th data from th rviw of th litratur. W obsrv that svral studis and dploymnts [, 6 2] us th yarly pric rosion of btwn 5% and 5%. Th srvic pric assumptions (prics and annual variation) ar prsntd in Tabl Broadband Markt Forcasts. Figur 2 shows th pntration forcast for DSL, HFC, fibr, and WiMAX for urban aras. In 22, for th urban ara, th xpctd pntration rats for th fixd tchnologis ar.5% for WiMAX, 4.25%

3 ISRN Communications and Ntworking 3 Tabl 3: Willingnss assumptions. Paramtrs Rgion (urban ara) Rgion 2 (rural ara) Srv. Srv. 2 Srv. Srv. 2 Monthly subscription f 2C C 2C C (Yar ) Willingnss valu 26C 65C 22C 55C Willingnss multiplir (%) Oprators markt shar: FTTH (PON) Y Y2 Y3 Y4 Y5 Y6 Y7 Y8 Y9 Y (%) Fixd broadband pntration forcast (Wstrn Europrsidntial markt) Estimatd Fixd BB pntration rat (urban ara) HFC DSL Fibr FWA (WiMAX) Figur 2: Fixd broadband pntration forcasts (2 22). for HFC, 22.7% for fibr, and 3.97% for DSL. In th rural ara, th xpctd pntration rat in 22 is.95% for HFC, 23.7% for DSL, 6.4% for fibr, and 7.5% for FWA. W also assum that in rural aras th FWA oprator has highr markt shar than in urban aras Comptitiv Situation and Oprators Markt Shar. In this sction, th markt shar (rlativ siz) of all th firms (oprators) is projctd. As comptition btwn oprators is diffrnt in ach ara, w stimat th markt shar for ach oprator dpnding on th ara, tchnology, srvic, and th markt (sfigur 3). 4. Gam Thory for Compting Modling With gam thory, w want to undrstand th ffcts of th intraction btwn th diffrnt playrs dfind in our businss cas. In th proposd gams, th profit (outcom) of ach oprator (playr) will b dpndnt not only on thir actions, but also on th actions of th othr oprators in th markt. This sction analyzs th impact of th pric (rtail and wholsal) variations on svral output rsults: playrs profit, consumr surplus, wlfar, costs, srvic adoption, and so on. For that, two pric-stting gams ar playd (Figur 4). Playrs profits and NPV ar usd as th payoff for th playrs in th gams analyzd. Urban ara: incumbnt Rural ara: incumbnt Urban ara: nw ntrant Rural ara: nw ntrant Figur 3: Markt shar pr oprator and rgion (FTTH markt). From th svral markts prsntd prviously, in this sction w prsnt th rsults for FTTH (PON) markt. W assum that two compting FTTH (PON) ntworks (incumbnt oprator and nw ntrant) ar dployd in both aras. For th gam-thortic modl, it is ncssary to chang th adoption modl usd in th tchnoconomic modl in a way that rflcts th comptition btwn playrs (s Figur 5). W assum that th variation of th srvics prics of on playr has an influnc on th markt shar of all playrs (dtaild in th nxt sction). In our modl w also us th Nash quilibrium to find quilibrium. Proposd tools includ a modul to sarch th Nash quilibrium in th gam. On stratgy is a Nash quilibrium whn both comptitors play thir bst stratgy rlatd to th othr stratgis slctd (playrs know ach othr s stratgy in advanc). 4.. Stratgis. To analyz th impact of rtail and wholsal srvics pric variations, w propos two gams (s Figur 4): () analysis of th impact of rtail pric variation on NPV (wholsal prics ar dfind by rgulator) and (2) analysis of th impact of rtail and wholsal pric variations on profit, consumr surplus, wlfar, and rtail/wholsal markt (diffrnt wholsal prics in ach rgion). For th gam-thortic valuation, th modl calculats th NPV and oprator s profit for both oprators pricing stratgis. Oprators NPVs ar usd as payoffs for th playrs in th first and scond gams, and oprators profits for th third gam. From th svral assumptions, w posit (a) th pric that playrs charg for thir srvics (rtail and wholsal) will b varid; (b) th rtail pric stting will influnc th markt shar of both playrs (rsulting in a highr or lowr markt shar); (c) consumrs only buy a rtail srvic if th pric is lss than thir willingnss to pay. As statd abov, w assum that whn on playr incrass/dcrass th rtail pric, th markt shar of all playrs will b affctd. For xampl, if on playr offrs chapr srvics, it will b abl to captur a highr markt shar. If a pric dcrass to narly zro, vryon will us th srvic, and th markt shar of this oprator will b clos to % (total markt). On th othr hand, if an oprator chargs a highr pric for a srvic, no on will subscrib to

4 4 ISRN Communications and Ntworking Tabl 4: Wholsal infrastructur assumptions. Paramtrs Rgion (urban) Rgion 2 (rural) Fdr sgmnt Distribution sgmnt Fdr sgmnt Distribution sgmnt Providr Duct availability % % 9% 9% Wholsal pric chargd to accss ducts (C/Km) C C C9 C9 Proportion of ducts lasd % % % % From oprator 2 2 Providr 2 Duct availability % % % % Wholsal pric chargd to accss ducts (C/Km) C C C9 C9 Proportion of ducts lasd 75% 75% % % From oprator Rtail/wholsal prics Gam Gam 2 Rtail prics Wholsal prics Rtail prics Wholsal prics Srvic Srvic 2 Rgion Rgion 2 Srvic Srvic 2 Rgion Rgion 2 x Euros/month y Euros/monthw Euros/month/ z Euros/month/ x Euros/month km/cm 2 y Euros/monthw Euros/month/ z Euros/month/ km/cm 2 km/cm 2 km/cm 2 Variation (multiplir factors).7,.8,.9,,.,.2,.3 Customr modl adoption.7,.8,.9,,.,.2,.3 Customr modl adoption.5,.75,,.25,.5 Calculat NPV, profit, CS, tc. Rgion Rgion 2 Rgion + rgion 2 Rgion Rgion 2 Rgion + rgion 2 Find NE NE stratgis NE stratgis Figur 4: Gams proposd. Markt shar variation (%) Rtail pric Playr -rtail pric Playr 2 f (x) f (bx + a) Boltzmann quation Figur 5: Modls to stimat th impact of th pric on th srvic adoption (a =.4, b = 3, dx =.3). th srvic from this playr and its markt shar will dcras to % Adoption Modl. Th impact of varying rtail prics on markt shars is stimatd using th Boltzmann quation Main Assumptions. W assum that th willingnss to pay for ach rtail srvic is diffrnt in both rgions. In th urban ara (rgion ), th maximum amount subscribrs would b willing to pay for srvic is 26 Euros and 65 Euros for srvic 2. In th rural ara w assum a willingnss valu of 22 Euros for srvic and 55 Euros for srvic 2 (s Tabl 3). For th wholsal infrastructur, w assum a duct availability of playr % in th urban ara and 9% in th rural ara. W also assum that oprator 2 (nw ntrant) lass % of th ducts availabl in th urban ara and % of th ducts availabl (oprator has only 9% and th rmaining % ar dployd by oprator 2) in th rural ara from oprator (incumbnt oprator). In th othr hand, playr lass th % rmaining (in rgion 2) from oprator 2. Th wholsal prics assumptions ar 9.C (month/km/cm 2 )forurbanaraand7.5c(month/km/cm 2 ) for th rural ara. Th wholsal infrastructur assumptions ar dscribd in Tabl 4. Th nxt sctions prsnt th thr gam rsults and analyss. In th first gam, rtail prics vary btwn tariff multiplir by.7 and.3 (in incrmnts of.). For th scond gam, rtail prics vary btwn.8 and.2, and wholsal prics btwn.5 and.5.

5 ISRN Communications and Ntworking 5 Total NPV (Euros)-oprator 2 (rgion and 2) Total NPV (Euros)-oprator (rgion and 2) Op. Rta.7.8 v. 2/ il pr r.9 S.9 ic m lir:.8 ultip. ltip lir: Srv ric mu. 2/O il p p. Rta Rta.7.8 /Op il pr rv. 2.9 ic m.9 S r: ultip.8 pli lir:..2.7 ulti m Srv.6 ic. 2/O.3 il pr p. Rta (a) (b) Figur 6: NPV variation: Oprator and 2/rtail srvic 2. Profit-total Profit-total Who l Rtail p 49 ric Pro v. (Sr v. 2) Prov 49 rv. 2) S 48 2 ( 47 Prov. 46 ric 45 tail p R Figur 7: Profit variation: rtail srvic 2. Tabl 5: Rtail prics variation valus. Tariff multiplir factor.7 Srvic pric 4 Srvic 2 pric Gam : Impact of Rtail Prics Variation on NPV. In this gam w assum that wholsal prics ar fixd and that oprators choos rtail prics to maximiz thir profit. Th impact of varying rtail prics on markt shars is stimatd using th Boltzmann quation (dscribd abov). Th main goal of this analysis is to dtrmin th optimal rtail pric stratgy for both playrs. Th rtail prics vary btwn 3% and 3%, with incrasing stps of % (Tabl 5). Th combination of th two rtail prics and svn multiplir factors lads to 49 possibl stratgis for ach playr (49 49 matrix) in ach rgion (2,4 total stratgis). 3 sal 2 pr ic 2 Pr ov. (lay r )-R 3 g. Prov 3 sa Whol 2 -Rg. yr ). 2 (la v o r P l pric 2 Prov 2 Figur 8: Profit variation: wholsal srvic. Tabl 6 prsnts th structur of th combinations and calculatd NPV. Th rsults (payoff matrix) of this gam ar prsntd in Figur which shows th sum of th payoffs of ach playr in both rgions. This tabl prsnts th NPV for both playrs for ach possibl combination of stratgis (on stratgy for ach playr); Nash quilibrium stratgis ar also idntifid. Th first two rows rprsnts th prics multiplir factor of Playr 2 (for srvics and 2) and th first two columns show th variation (multiplir factors) of Playr. Each cll contains two valus: Th lft valu corrsponds to th NPV of Playr, and th valu on right sid corrsponds to th NPV of Playr 2. For xampl, th first valu calculatd (58324C) corrsponds to th NPV of Playr whn th stratgy of Playr is to dcras th pric of Srvic and srvic 2 by about 3% (multiplir factor.7) and th stratgy of Playr 2 is also to dcras th pric of srvic and srvic 2 by about 3%. From ths rsults prsntd in Figur, w find thr pur NE stratgis (black clls) that ar dscribd in Tabl 7. Tabl 7 shows th NE stratgis that maximiz th profit of

6 6 ISRN Communications and Ntworking Tabl 6: Structur of combinations and rsults for Gam. Playr Playr 2 NPV Rtail Pric Rtail Pric Playr Playr 2 Tot. P Tot. P2 Stratgis R and R2 R and R2 R R2 R R2 R + R2 R + R2 S S2 S S n Tabl 7: Pur NE stratgis for both rgions. Stratgy Playr (incumbnt) Playr 2 (nw ntrant) Rtail srv. Rtail srv. 2 Rtail srv. Rtail srv. 2 NPV KC Playr NPV KC Playr 2.(22C).(55C).7(4C).8(4C) (24C).2(6C).3(26C).(55C) (26C) (C).2(24C).7(35C) Tabl 8: Rtail and wholsal prics variation valus for Gam 2. Srvic Tariff multiplir factor Rtail pric Wholsal pric Rtail pric Prov. (Srv. 2) Total Consumr surplus-total Rtail pric Prov. 2 (Srv. 2) Subsc Providr Providr 2 Rtail markt 2 Rtail pric Prov. (Srv. ) Figur : Rtail markt variation. Rtail pric Prov. 2 (Srv. ) Figur 9: Consumr surplus variation. both playrs. To maximiz profit, in th first quilibrium stratgy, Oprator incrass rtail prics by %. Oprator 2, in fac of th imposd wholsal prics, dcrass th pric of srvic and srvic 2 by 3% and 2%, rspctivly. A nw ntrant has to pay th wholsal to th incumbnt, but if incras th rtail prics, thir markt shar will dcras (s modl abov). Figur 6 shows th impact of srvic 2 variation on NPV of both oprators. From th analysis of Figur 6, wcan conclud that th variation of rtail prics of Srvic 2 has a gratr influnc in th NPV than th variation of Srvic pric. Srvic 2 pric variation can drop th NPV of Oprator to ngativ. On th othr hand, Oprator 2 can turn th NPV positiv whn th tariff of srvic 2 incrass. Gam 2: Impact of Rtail and Wholsal Prics Variation on NPV. In this gam w assum that wholsal prics ar not primposd, and w invstigat what is th raction of oprators whn thy can also choos diffrnt wholsal prics in diffrnt rgions (s Tabl 8). In gam 2 w assum that has th sam variation for both rgions. Rtail prics vary btwn.8 ( 2%) and.2 (2%) (in incrmnts of.). For wholsal pric w assum a variation btwn.5 and.5 (in incrmnts of.25). In this contxt, th combination of th thr prics and variation multiplirs (dscribd in Tabl 8) lads to 625 (5 4 ) possibl stratgis for ach playr ( matrix) in ach rgion (39625 stratgis in both rgions) Tabl 9 shows th structur usd. As th matrix is too biggr, for this gam w dcid to prsnt th NE stratgis (playrs profit is usd as payoff)and th graphs that show th impact of variation in svral rsults (prsntd in Figur 2). Th analysis of th rsults finds fiv NEs stratgis. As Playr 2 dos not oprat in th wholsal markt of rgion, thvariationofthispricisnotsignificant (stabl ). W

7 ISRN Communications and Ntworking 7 Tabl 9: Structur of combinations and rsults for Gam 2. Playr Pl 2 Rsults-NPV Stratgis Rtail pric Wholsal pric Playr Playr 2 Tot. P Tot. P2 R and R2 R R2 R R2 R R2 R + R2 R + R2 S S2 Duct Accss n Tabl : Pur NE stratgis in both rgions (Gam 2). Playr (incumbnt oprator) Playr 2 (nw ntrant) Rtail Wholsal Rtail Wholsal Profit (KC)Playr Profit(KC)Playr2 S S2 R R2 S S2 R R Playr (incumbt oprator) stratgis Pric S Pric S ,,,,,, ,,,,,,,,,.3.7,,,.,,, Playr 2 (nw ntrant) stratgis,,, Figur : Gam rsults summary conclud that, in th businss cas dfind, whn oprators can charg diffrnt rtail and wholsal prics, thy choos to incras wholsal prics. To maximiz profits, oprators incras wholsal prics and dcras rtail prics. Howvr, th incras in wholsal prics prcluds ntry of nw oprators into th markt. Th main rsults of this gam ar summarizd in th nxt figurs. In th graphs w can s th impact of rtail prics (Figur 7) and wholsal prics(figur 8) on playrs profit. W can vrify that both prics can turn profit positiv/ ngativ. As xpctd, consumr surplus dcrass with th incras of prics (Figur 9). As also prdictabl and modld abov th impact of rtail prics, variation has highr influnc in th markt shar of comptitors (s Figur ). Th comparison of th two gams abov shows that whn th rgulator dfins wholsal prics, oprators incras rtail prics to maximiz profit. Howvr, whn wholsal

8 8 ISRN Communications and Ntworking Playr stratgis R Pric S R Pric S2 W Pric R W Pric R2..5, ,25, Playr 2 stratgis Figur 2: Gam 2 rsults summary prics ar not rgulatd, oprators maximiz profit by dcrasing rtail prics and incrasing wholsal prics. Howvr, without rgulation, th highr wholsal prics will limit th ntranc of nw comptitors. 5. Conclusions Th Europan Commission argus that infrastructur-basd comptition is th bst and fastst way for broadband dvlopmnt. Th argumnts ar that infrastructur-basd comptition provids fficincy incntivs to oprators, rducs prics, incrass pntration, stimulats innovation, and so on. On th othr hand, srvic-basd comptition implis that th nw ntrants (altrnativ oprators) ar dpndnt on th incumbnt. Howvr, bcaus of th high costs of dploying infrastructurs (spcially trnching and ducting), srvic comptition has bn usd as a substitut or complmnt to infrastructur comptition. In rgions with lowr numbrs of xisting accss infrastructurs, nw ntrants ar obligatd to build thir own infrastructur. In this way, infrastructur sharing can stimulat th construction of nw accss infrastructurs that can b lasd to othr oprators. Th rsults of this invstigation show that th sharing of passiv infrastructurs (.g., ducts, trnching, bas station sits, and antnna masts) is a viabl stratgy, particularly in th contxt of nw building (in scnarios with dvlopd accss infrastructur). Whn an oprator dploys an accss ntwork, th accss to xisting civil nginring significantly rducs th invstmnt. Thr ar strong argumnts to b mad for allowing infrastructur sharing. In this contxt, rgulators must guarant nw ntrant oprators accss to civil nginring; this will stimulat invstmnt in nw ntworks. Th rduction of th barrirs to nw infrastructur invstmnt by opning passiv xisting infrastructur would b ky in th futur. This study has shown that in rural aras, charactrizd by a small numbr of dvlopd accss infrastructur, th accss to civil nginring dos not mak th scnario conomically viabl for th oprator. Rfrncs [] S.L.Kota,Satllit Multimdia Ntworks and Tchnical Challngs, Microwav Rviw, 26. [2] O. C. Ib, Fixd Broadband Wirlss Accss Ntworks and Srvics, John Wily & Sons, 22. [3] J. P. R. Prira and P. Frrira, Accss ntworks for mobility: a tchno-conomic modl for broadband accss tchnologis, in Procdings of th 5th Intrnational Confrnc on Tstbds and Rsarch Infrastructurs for th Dvlopmnt of Ntworks and Communitis and Workshops (TridntCom 9), pp. 7, April 29. [4] J. S. Marcus, D. Elixmann, C. Wrnick t al., Nxt Gnration Ntworks (NGNs), Europan Parliamnt, 29. [5] F. Kirsch and C. Von Hirschhausn, Rgulation of NGN: structural sparation, accss rgulation, or no rgulation at all? in Procdings of th st Intrnational Confrnc on Infrastructur Systms and Srvics: Building Ntworks for a Brightr Futur (INFRA 8), pp. 8, Novmbr 28. [6]C.JaagandM.Lutznbrgr, ApproachstoFTTH-rgulation. An Intrnational Comparison, in Procdings of th 2nd Annual Confrnc on Comptition and Rgulation in Ntwork Industris, p. 23, 29. [7] J. P. Prira, Tlcommunication Policis for Broadband Accss Ntworks, in Procdings of th 37th Rsarch Confrnc on Communication, Information and Intrnt Policy, pp. 3, 29. [8] Analysys-Mason, Tlcoms infrastructur accss sampl survy of duct accss, Ofcom, 29. [9] J. P. Prira and P. Frrira, Nxt Gnration Accss Ntworks (NGANs) and th gographical sgmntation of markts, in Procdings of th th Intrnational Confrnc on Ntworks (ICN ), p. 6, 2. [] J. Rndón, F. Kuhlmann, and J. P. Aranis, A businss cas for th dploymnt of a 4G wirlss htrognous ntwork in Spain, in Procdings of th 8th Europan Rgional Intrnational Tlcommunications Socity, 27.

9 ISRN Communications and Ntworking 9 [] T. Monath, N. K. Elngaard, P. Cadro, D. Katsianis, and D. Varoutas, Economics of fixd broadband accss ntwork stratgis, IEEE Communications Magazin, vol. 4, no. 9, pp , 23. [2] F. Loizillon, J. Harno, I. Wlling t al., Final rsults on samlss mobil IP srvic provision conomics, IST-Information Socity Tchnologis, 22. [3] T. Monath, Tchno-conomic rsults for fixd accss ntwork volution scnarios, in Book Tchno-Economic Rsults for Fixd Accss Ntwork Evolution Scnarios, Tchno-Economic Rsults for Fixd Accss Ntwork Evolution Scnarios, p. 28, 25. [4] Analysys-Mason, Th costs of dploying fibr-basd nxtgnration broadband infrastructur, Analysys-Mason, Broadband Stakholdr Group, 28. [5] CSMG, Economics of Shard Infrastructur Accss, 2. [6] K. Stordahl, Broadband dmand and th rol of nw tchnologis, in Procdings of th Th 3th Intrnational Tlcommunications Ntwork Stratgy and Planning Symposium,pp. 23, 28. [7] K. Stordahl, Markt dvlopmnt up to 25, MARCH Multilink architctur for multiplay srvics, 2. [8] K. Stordahl, L. A. Ims, and B. T. Olsn, Risk mthodology for valuating broadband accss ntwork architcturs, Tlktronikk, vol. 2, no. 3, pp , 999. [9] V. Riihimäki, Managing Uncrtaintis in Broadband Invstmnts Cas Studis of Ral Options for Rural Ara Accss Ntworks, Dpartmnt of Communications and Ntworking, Aalto Univrsity, Aalto, Fnland, 2. [2] Europan-Union, Europ s Digital Comptitivnss Rport 2, Europan Union, 2.

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