Edge Node to Remote Node Topology Optimization in

EdgeNodetoRemoteNodeTopologyOptimizationintheRapidlyDeployableRadioNetwork(RDRN)ShaneM.HaasDr.DavidW.PetrJohnPadenMay31,1997AbstractThisreportexplainshowtheRapidlyDeployableRadioNetwork(RDRN)establishestheconnectionsbetweenanedgenodeanditsassociatedremotenodes.TheRDRNtriestomaximizetheminimumsignal-to-interferenceratiooftheremotenodesbyoptimallydecidingthenumberradiobeamstoform,thedirectiontosteereachbeam,therelativepowerofeachbeam,andtheassignmentofbeamstoremotenodes.ThisreportdocumentshowtheRDRNmakesthesedecisions.Contents1Introduction22Background22.1RDRN’sStructure........................22.2Signal-to-InterferenceRatios...................33OptimizingtheSignal-To-InterferenceRatios43.1ChoosingtheServerMap.....................53.1.1RepresentingaServerMapasaNumber........53.1.2CreatingallPossibleServerMaps............53.1.3RedundantServerMaps.................63.2ChoosingtheNumberofBeams.................83.3ChoosingtheBeams’SteeringAngles..............83.4ChoosingtheBeams’RelativePowers..............93.5OptimizationSummary......................104Example104.1TheServerMap110.......................114.2TheServerMap010.......................125Conclusions14ACode18A.1BeamTable.h...........................18A.2complex.h.............................22A.3gps.h................................24A.4opt-steer-ang.h..........................26A.5complex.c.............................32A.6opt-steer-ang.c..........................35A.7optimize.c.............................4911IntroductionThisreportexplainshowtheRDRN[1]establishestheconnectionsbetweenanedgenodeanditsremotenodes1.TheRDRNmakestheseconnectionsbydecidingonthefollowing:1.Theassignmentormappingofradiobeamstoremotenodes.Thisassingmentistheedgenode’sservermap.2.Thenumberofradiobeamstoform.3.Thedirectionorsteeringangleofeachbeam.4.Therelativepowerofeachbeam.TheRDRNmakesthesedecisionstomaximizetheminimumsignal-to-interferenceratiooftheremotenodes.ThisreportdocumentshowtheRDRNmakesthesedecisions.Section2explainstheedgenodetoremotenodetopologyprobleminmoredetail.Section3showshowtheRDRNdeterminestheservermap,numberofbeams,steeringangles,andbeampowers.Section4givesanexampleofanedgenodetoremotenodeconguration.Finally,AppendixAexplainstheintegrationofthissoftwareandliststheCcodethatimplementsthesealgorithms.2BackgroundThissectiondescribesthegeneralstructureoftheRDRNandthesignal-to-interferenceratios(SIRs)oftheremotenodes.2.1RDRN’sStructureAsFigure1illustrates,theRDRNconsistsoftwotypesofnodes:edgenodesandremotenodes.TheedgenodesareATMswitchesthatformthenetworkbackbone.Eachedgenodeservesasetofremotenodesbyformingmultiplesteerableradiobeams.WhentheRDRNpowersup,whenanewedgenodeisintroducedintothenetwork,orwhenanedgenodemoves,theRDRNestablishesahighspeed1Switchnodesandusernodesarealternativenamesforedgenodesandremotenodes,respectively.2ToOtherEdgeNodesorExistingInfrastructureEdgeNode=EdgeNodetoEdgeNodeRadioLink===RemoteNodeEdgeNodetoRemoteNodeRadioLinkFigure1:TheRDRNconsistsofedgenodesandremotenodes.communicationpathbetweenalledgenodesbasedonaconsistentlabelingproblemalgorithm[2].Afterestablishingtheedgenodebackbone,theRDRNassignseachre-motenodetoanedgenode.Eachedgenodehasanantennacapableofformingmultipleelectronicallysteerableradiobeamstoestablishacom-municationpathwayfromitselftotheremotenodesthatitserves.Fur-thermore,eachradiobeamcanserveseveralremotenodessimultaneouslythroughTDMAorCDMAmultiplexing.Figure2showsanedgenodeform-ingtworadiobeamstoserveveremotenodes.Thisgureillustratestheproblemscopeforthisreport.2.2Signal-to-InterferenceRatiosBecauseeachbeamoperatesonthesamecarrierfrequency,theywillinterferewitheachotherwhentransmitting.Inotherwords,aremotenodereceivesinformationfromnotonlyitsservingbeam,butfromeveryotherbeamaswell.Thesignal-to-interferenceratio(SIR)quantiesthisinterferenceateachremotenode.TheSIRofaremotenodeisSIR=PowerfromservingbeamPPowerfromallotherbeamsInwords,theSIRofaremotenodeistheratioofitsservingbeam’spower3s1s2s3ProblemBoundaryRadioBeamsRemoteNodesEdgeNodesFigure2:Anedgenodeformstworadiobeamstocommunicatewithveremotenodes,illustratingtheproblemscopeofthisreport.tothesumoftheotherbeams’powers.AhigherSIRcorrespondstobetterreceptionatanode.TheSIRisdependentuponthepowerfromallthebeamsformedbyanedgenodeattheangularlocationoftheremotenode.TheSIRisnotdependentuponthephysicaldistanceoftheremotenodefromtheedgenode.Theedgenodechoosestheservermap,numberofbeams,steeringangles,andbeampowerstoincreasetheleastSIRofitsremotenodes.3OptimizingtheSignal-To-InterferenceRa-tiosAnedgenodemustdecidetheappropriateservermap,numberofbeams,beamsteeringangles,andbeampowerstomaximizetheminimumSIRofitsremotenodes.Thissectiondescribeseachofthesedecisionsindetail.43.1ChoosingtheServerMapAservermapisamappingoftheedgenoderadiobeamstotheremotenodesthateachbeamcommunicateswithorserves.Anedgenodewillcreateeverypossibleservermap,decideifeachservermapisredundant,andperformsteeringangleandpoweroptimizationonthosethatarenotredundanttodecidewhichservermapallowsforthelargestminimumSIRofi