Määritelmä
Mobilecommunications(mobilecommunications)Communicationbetweenmobileusersandfixed-pointusersorbetweenmobileusers.
Communicationnetworkisasystemthatusesswitchingequipmentandtransmissionequipmenttointerconnectgeographicallydisperseduserterminalequipmenttoachievecommunicationandinformationexchange.
Mobilecommunicationnetworkisanimportantbranchofcommunicationnetwork.Becauseofitsmobility,freedom,andfreedomfromtimeandlocation,wirelesscommunicationiswidelywelcomedbyusers.Inthefieldofmoderncommunication,itisoneofthethreeimportantcommunicationmeansalongsidesatellitecommunicationandopticalcommunication.
Luokittelu
Thecurrentmobilecommunicationnetworkcanbedividedintotwo-wayconversationalcellularpublicmobilecommunication,one-wayortwo-wayconversationalprivatemobilecommunicationaccordingtothecoverageandoperationmodeofthesystem.,One-wayreceivingwirelesspaging,homecordlessphoneandwirelesslocaluserloop,etc.
Fromanetworkperspective,mobilecommunicationnetworkscanbedividedintopublicmobilecommunicationnetworksandprivatemobilecommunicationnetworks.
Thefollowingisanintroductionfromthenetworktopologyofthecommunicationnetworkandrelatedservices:
2.1Julkinen matkaviestinverkko
Publicmobilecommunicationnetworkgenerallyadoptscellulartopology.Basedontheconsiderationofincreasingspectrumutilizationandreducingmutualinterference,increasingsystemcapacity.Thecellsystemusedisahexagonalstructurewithacoverageradiusoflessthan10km;thereisalsoahybridstructureofmicrocellsandpicocells.Cellularmobilecommunicationtechnologyhasmaturedwiththeemergenceofmicrocellsandpicocells.Theradiusofthesemicrocellsisgenerallyafewmeterstoafewhundredmeters.Theradiusoftheoperatingcellisseveralkilometers.Micro-celltechnologywillexpandserviceprocessingcapabilitiesbyreusingfrequenciesandthe"extensioncomponent"oflargebasestations-low-powertransmitters.Thismethodisalsosuitableforareaswithpoorwirelesscoverage.Theintelligentnetworkdatabasewilltracktheusersofthepersonalcommunicationnetwork(PCN)andmovefromonemicrocelltoanother.
2.2Yksityinen matkaviestinverkko
Theprivatemobilecommunicationnetworkisanindependentmobilecommunicationsystemthatcanalsobeincorporatedintothepublicnetwork.Arepresentativeprivatenetwork-trunkingsystem(TrunkingSystem).Inadditiontocellularnetworks,thisisanothereffectivewaytoimprovespectrumutilization.Theso-called"cluster",inthesenseofcommunication,istoautomaticallyallocatelimitedcommunicationresources(channels)toalargenumberofusersforcommonuse.Thiskindofhigh-efficiencynetworkhasbeenverypopularinrecentyears.Ofcourse,withthedevelopmentofpublicnetworktechnology,itwillautomaticallybeincorporatedintotheprivatenetwork.