Персонална удобна телефонна система

ThesynonymPHSgenerallyreferstoapersonalhandheldphonesystem

TheabovecontentisreviewedandannouncedbytheNationalScienceandтехнологияTermReviewCommittee

Въведение

PersonalhandheldphoneSystem(PHS——-personalhandyphonesystem)technologyoriginatedinJapan,andithasbeendevelopedinJapanasasecond-generationmobilecommunicationtechnology.OurcountrymakesfulluseoftherichresourcesofthefixedtelephonenetworkandorganicallycombinesthelocaltelephoneexchangeandtransmissiontechnologytoformPHS,commonlyknownas"LittleSmart".ThePHSnetworkhasafastnetworkconstructionspeed,asmallinvestment,andiseconomicalandconvenient.

технология

PHStechnologyisactuallyadigitalmobilecommunicationtechnology,whichbelongstothesecondgenerationofcommunicationtechnology.ThecoverageofPHSbasestationsislimited,andthedistancebetweencommunicationbasestationsandterminalsisrelativelyshort.Therefore,thecommunicationpowerusedissmaller,andmorebasestationsarerequiredtocoveralargerarea.ThismakesPHSmoresuitableforuseinurbanareas,buttheeffectisnotgoodwhenusedinthefieldandotherplaces.Inthegenerationofmobilephonecommunicationspeed,PHSbelongstotherangeof2G.Itsdesignalsocausesaslightdelayduringthecall.(Becauseofitssmallcoverageareaandsmall"cellular"area)

PHSusesTDMA/TDDasitsradiocommunicationinterface,and32KADPCMasitsvoicetransmissioncode.ModernPHSphonescanalsosupportsomeotherISP'svalue-addedservices,suchasInternetnarrowbandcommunications,textmessages,e-mail,andevenimagemessaging.

PHSthistechnologyisalsosuitableforsmall-scaleradiocommunications.

Използвайте

Theinitialreleasewasin1989attheNTTlaboratoryinJapan,asaformoftechnologycompetingwithGSMandPDC.Intheearlydays,itwasdevelopedbyJapanbasedonitsownnationalconditions(thecharacteristicsofhighpopulationdensityinmostplacesandlowpopulationmobility).In1995,itwasinitiallyoperatedbythreetelecomoperatorsinJapan:NTT-Personal,DDI-PocketandASTEL.However,shortlyaftertheservicewaslaunched,duetoinsufficientcoverageandroamingcapabilities,thetechnologywascalled:"PoorMan’sCellular"InJapan,itisheavilyrestricted.Themarketshareisalsograduallydecreasing.SomecountriesthatoriginallyusedPHStechnologyhavealsobeguntouseGSM,suchasChile.However,thePHStechnologyisalsopopularinsomecountriesandregionswithlowerfeesandfeweradditionalservices,suchasChina,Taiwan,Vietnam,Bangladesh,Nigeria,Mali,TanzaniaandHonduras.

AfterthePHSservicewasterminatedat24:00onDecember31,2014,somePHSusersinBeijinghaverepeatedlycomplainedtoandnegotiatedwithBeijingUnicom.Butintheend,thetwopartiesfailedtoreachanagreementoncompensationissuesaftertheterminationoftheservice.ChinaUnicomBeijingBranch(hereinafterreferredtoasBeijingUnicom)terminatedthesuspectedmonopolyandinfringementofPHSbusinessisthefirstanti-monopolylawsuitinthewithdrawalofPHS.

PHSmarket

InMainlandChina,ChinaTelecomandChinaUnicom’sPHSservicesusePHStechnologyinmostplaces.InTaiwan,VolkswagenTelecom'slow-powermobilephonesalsousePHStechnology.

Обхват на бизнеса

Inadditiontobasicvoiceservicesandsupplementaryservices,thePHSnetworkalsoprovidesthefollowingvalue-addedservices:

1.SMSservices:PHSSMSservicesandmobileTheshortmessageserviceofthephoneissimilar,anditcansendandreceivetextmessagesoflimitedlengthfromPHSterminals.

2.Dataaccessservice:PHSsystemhasgoodhigh-speedwirelessdatacarryingcapacity,itssingleservicechannelcancarry32KBPSofunrestricteddata,anditcansupport64KBPSofwirelessdataservicebybundlingtwoservicechannels.TheterminalpartcanbeaPHSmobilephonefordirectdataservices(thecomputerisconnectedtothemobilephonethroughaspecialcableforthePHSmobilephone),orotherformsofdataterminals,suchasanetworkcardsuitableforcomputers.

3.Colorringbacktoneservice:referstotheringbacktoneofspecialsoundeffects(music,song,storyplot,characterdialogue)setbythecalleduserforothercallinguserswhotransferthecalltothemobilephone.

4.Blindareacallingbusiness.

5. ТерминалИнтернетбизнес.

6. Позициониране на бизнеса.

7. Предплатен бизнес.

Предимства и недостатъци

1.Предимства

·Опазване на околната среда

ThePHShaslowpowerconsumption,verysmallelectromagneticwaveradiation,andradiationtothehumanbodyTheharmissmall,anditisstilllovedbysomespecialgroups,suchastheelderly,pregnantwomen,andmedicalstaff.Longstandbypowersaving:PHSconsumeslesspowerandhasalongstandbytime.Chargeitonce,thestandbytimecanreach10days,savingthetroubleoffrequentcharging.

·Изключителна честотна лента

ThecallqualityofPHScanbecomparabletofixed-linephoneswithinthenetworkcoveragearea;unlikemobilewirelessInternetmulti-personsharing,PHScanenjoy64/128Kbpsbandwidth.

· Грабусъри

PHSisaproductofaspecialperiod.ItwasalsothehelplessmoveofChinaTelecomandChinaNetcomwhentheydidnothavemobilelicenses,buttheyalsoseizedalargenumberofoperatorsbefore3G.user.

2.Недостатъци

· По-малко функции

ThePHShasfewerauxiliaryfunctions.EarlyshortmessagescanonlybesentbetweenthePHSs,browsetheInternetandusemobilephones.Manyfashionablenewfeatures,suchasgames,areonlybeingperfectedinthelaterstages.

· Слабо покритие

Thenetworkcoverageispoor,generallylimitedtotheurbanarea,withpoorsignal;therearefewbasestations,andthecallisnotsmoothinsomepartsofthecity,anditisimpossibletocallintheeventofapoweroutage.

·Слабо представяне

Whenthevehiclespeedexceeds40kilometers,thecallisintermittent.AlthoughJapanisconstantlyimprovingitstechnology,itisbasicallynolongerdevelopinginthecountry.

·Канотроам

PHScannotroamacrossthecountrylikeamobilephone,soitcanonlybeusedasa"fixed-linesupplementandextension",andthereisalwaysagapbetweenthefunctionandthemobilephone.

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