Connectivity Management on Mobile Network Design

ConnectivityManagementonMobileNetworkDesignPhilipp e Reiningeryand AlexandreCaminadaFranceTelecom CNETBP382 - F90000 Belfort - France{alexandre.caminada!philipp e.reininger}@cnet.francetelecom.fr15th April 1998AbstractThispap erdealswithamathematicalmo delfordesigningcellularnetwork.Themo delallowsusto nd the optimal lo cation for sites and the opti-malparameterization forradiotransmitters.Theproblem is mo deled by discretizing the radio cover-ageareas intoreceiver lo cations,servicelo cationsand site lo cations.We use a concentrator lo cationapproach in which a set of test p oints must b e at-tachedtositesinorder tosupplyagiven service.The mo del includes sp ecic constraints to deal withnetwork and cells connectivity problems.Netorkconnectivity will ensure mobility inside the networkdesigned.Whencellsconnectivitytakesintoac-countthedierencomp onentsofcellstoreduceinterference b etween cells.The nal mo del denesanob jectivefunctiontominimizethenumberofsitesandintegratesconnectivityservicecon-straints.1Intro ductionThedeployment of cellular networks isone ofthemostchallengingdealofthislastdecade.Ahighcomp etitionbetweenradioop eratorsallovertheworldleadsthemtondtheoptimalayofde-signingtheirnetworkattheloercost,whenen-suring the b est Quality of Service (QoS). It could b eachieved by considering the radio planning problemas an optimization problem.Thisworkis supp ortedbytheECDGIIIundercontract NR IT-23243yLSI IT(UPRES-ACNRS7005),PoleAPI,b oulevardSebastien Brant, F-67400 Illkirch Cedex, FRANCETheradioplanningofcellularnetworkimpliestwo conception stages: dimensioning and designing.Thedimensioningstepdenesthenancialneedsto design a cellular netork regarding at trac andcoverage ob jectives.Whereas the aim of the designis to nd the lo cations and the parameters of radioEquipment for network deployment.After dimen-sioning, when all resources are dened, the problemof designing can b e considered as a resource opti-mization problem.In fact the complexity of cellularnetwork design strongly dep ends on the number ofsites and base stations (BS). There is consequentlya strong incentive to develop designing to ols whichminimize the numb er of BS and optimize their lo-cation to achieve trac and coverage ob jectives.Nowthenextstepofnetorkdesignistointegratethepro cessmanagementofcon-nectivityconsideration.Oneofthemostimp or-tant problem in the design is to ensure the mobil-ityinsidethenetworkwithaconstantQualitofService.Every subscrib er must b e able to move in-sidethecoverareawithoutlo osingsignal.Itcould b e done byintegrating in the design sp ecicconstraintstotakeinaccounttherequiremenofnetworkandcellsconnectivity.Netcon-nectivity is directly involved in the mobility, it willallow the subscrib er to continuously move from onep ointofthenetwork toanother p oint.Cells con-nectivity is linked to the Quality of Service.Adja-centcellsgenerateinterference,theyoverlap eachother.Reducing the numb er of adjacent cells couldb e done by reducing the numb er of connected com-p onents of each cell.To manage with connectivityconstraints on network and cells during the pro cessofdesignistheaimprop osaldescrib edinthis pap er.1