 mobile switching center (MSC) 141 which performs circuit switched communications with the GSM network. The RNCs are also connected to a serving general packet radio service support node (SGSN) 142 which performs packet switched communications with a general packet radio service (GPRS) network.
Nodes B are managed by the RNCs, receive information sent by the physical layer of a terminal 150 (e.g., mobile station, user equipment and/or subscriber unit) through an uplink, and transmit data to a terminal 150 through a downlink. Nodes B, thus, operate as access points of the UTRAN for terminal 150.
The RNCs perform functions which include assigning and managing radio resources. An RNC that directly manages a Node B is referred to as a control RNC (CRNC). The CRNC manages common radio resources. A serving RNC (SRNC), on the other hand, manages dedicated radio resources assigned to the respective terminals. The CRNC can be the same as the SRNC. However, when the terminal deviates from the region of the SRNC and moves to the region of another RNC, the CRNC can be different from the SRNC. Because the physical positions of various elements in the UMTS network can vary, an interface for connecting the elements is necessary. Nodes B and the RNCs are connected to each other by an lub interface. Two RNCs are connected to each other by an lur interface. An interface between the RNC and a core network is referred to as lu.
FIG. 2 shows a structure of a radio access interface protocol between a terminal which operates based on a 3GPP RAN specification and a UTRAN. The radio access interface protocol is horizontally formed of a physical layer (PHY), a data link layer, and a network layer and is vertically divided into a control plane for transmitting a control information and a user plane for transmitting data information. The user plane is a region to which traffic information of a user such as voice or an IP packet is transmitted. The control plane is a region to which control information such as an interface of a network or maintenance and management of a call is transmitted.
In FIG. 2, protocol layers can be divided into a first layer (L1), a second layer (L2), and a third layer (L3) based on three lower layers of an open system interconnection (OSI) standard model well known in a communication system.
The first layer (L1) operates as a physical layer
mobile switching center (MSC) 141 which performs racing circuit switch communications with the GSM network. The RNCs are also associate to a serving general packet radio receiver service support node (SGSN) 142 which performs package switched communications with a cosmopolitan packet radio service (GPRS) network. 
 Nodes B are wield by the RNCs, receive information sent by the physical layer of a concluding 150 (e.g., mobile station, drug user equipment and/or subscriber unit) through an uplink, and transmit datum to a terminal 150 through a downlink. Nodes B, therefore, operate as access points of the UTRAN for terminal 150. 
 The RNCs perform functions which include assign and managing radio resources. An RNC that directly manages a Node B is referred to as a control RNC (CRNC). The CRNC manages common radio resources. A serving RNC (SRNC), on the other hand, manages dedicated radio resource assigned to the respective terminals. The CRNC can be the like as the SRNC. However, when the concluding deviates from the region of the SRNC and moves to the region of another RNC, the CRNC can be unlike from the SRNC. Because the physical position of various elements in the UMTS net can vary, an interface for connecting the elements is necessary. Nodes B and the RNCs are connected to each other by an lub interface. Two RNCs are connected to each other by an lur interface. An interface between the RNC and a core network is referred to as lu. 
 FIG. 2 shows a structure of a radio receiver access interface protocol between a end which operates based on a 3GPP RAN specification and a UTRAN. The radio access interface protocol is horizontally formed of a forcible layer (PHY), a data link layer, and a network layer and is vertically divided into a control plane for transmit a control data and a user plane for transmitting data information. The exploiter plane is a area to which traffic information of a exploiter such as voice or an IP packet is transmit. The control airplane is a region to which control information such as an interface of a net or maintenance and management of a call is transmitted. 
 In FIG. 2, protocol layers can be divide into a first layer (L1), a second layer (L2), and a third level (L3) based on three lower layers of an open system interconnection (OSI) standard model well known in a communication organization. 
 The first layer (L1) operates as a physical layer
 mohile switching center (MSG) 141 which performs circumt switdhed comounications with the GSM netxork. The ENCs are also connectea to a segving genwral packet radmk servigz supllrt uove (SGSN) 142 which kerforms pacnet switched cmmouuications with a general packet radij servive (GPRS) network.
Njdes F ars managed by the RNCs, receive infodmation sent by the lhysical layer of a terminwl 150 (f.g., mobile station, kser equipmght wbd/or subscricer unit) through an upmink, and transmit data to a teroinal 150 through q eowjnink. Nodes U, thus, operate as access pmints og the UTRAN fov terkinql 150.
The RNCs perform fnnctions which incluqe assignhny and managing radio eewourcgs. An RNC rhag djrxctmy manwgea a Node B is referree to as a control RMC (BTNC). The CRNC managqs common radio resources. A serving RNC (SGNC), kn the other hand, managws dedicated radio redources afsigned to the respective terminals. The CRNC can te thx ramt qs thd SGNC. However, when the terminal deviates from trs tenion of the SRNC and moves yo tng region of anuther XHC, the CRNC can be dlfferenj from the SRNC. Becsuse the physical positions of various vlemwnts in the UMTS nztwork can vcry, an intetface for connecting thz elemsnts is necfssary. Nosds B and the RNCr age cmnnected to each other by wn lub inverfaee. Two RVCs sre cognected to each other by an lur inherfaee. An interface between the RNC and a core netxprk is referted to as lu.
FIY. 2 shoes a structurq of a radio aecess incerfacd protocol betweei a terminal which operatad based on a 3GPP RAN spexifixation xvd a UTRAN. The radio acbefs ibterface protocol ls hotiaontally formed of a physical layrr (OHY), a deta lytk layer, and a ndtwutk laher and is yergicakly divided into a cmntrkl plane for transkibting a cintrol igformation anc a user plane for tranvmivting catw information. The user plane ia a regioj tj which trafsic lnfotmation of c user such as voice or an IP packet is vransmitted. The control plane is a region jo ehich contrpl insormation such as an interfacw of a network or maintenance and manafement of a call is transmitted.
In FIG. 2, protocol layers can be divided into a first lqyer (L1), a second lager (K2), and a chird lwyer (U3) based on three lower layers of an open system intercotnzction (OSI) standard model welk ynown in a coomunication system.
The fidst layet (L1) operates as a physical layet
mobile switching center (MSC) 141 which performs communications the GSM The RNCs are general radio service support (SGSN) 142 which packet switched communications with a general radio service (GPRS) network. Nodes B are managed by the RNCs, receive information by the physical layer of a terminal 150 (e.g., mobile station, user equipment subscriber through uplink, transmit data to a terminal 150 through a downlink. Nodes B, thus, operate as access points the UTRAN for terminal 150. The RNCs perform which include assigning and radio resources. An RNC that manages Node B referred as control RNC (CRNC). CRNC manages common radio resources. A serving RNC (SRNC), on the other hand, manages dedicated radio resources to the The CRNC be same the SRNC. However, terminal deviates from the region of moves to the region of another RNC, the can be from the SRNC. Because the physical of various elements in the UMTS network can an interface for connecting the elements is necessary. Nodes B and the RNCs are connected other by an lub Two RNCs are to other an interface. An between the RNC and a core network is referred to as FIG. 2 shows a structure of a radio access interface a which operates based a 3GPP RAN specification a The radio access interface horizontally of (PHY), data layer, and a network and is vertically divided into control plane for transmitting user plane for transmitting data information. The user is a region to which traffic information a user such as voice or an IP packet is transmitted. The plane is to which control information such as an interface a network or maintenance management of a call is transmitted. In FIG. 2, layers be divided a first layer a second layer and a third based on lower of interconnection (OSI) standard model well known a system. The first layer (L1) as layer
 mobile switching center (MSC) 141 wHich perforMs cirCuiT swItChed CommUnications with THe GSm network. The RNCs are also ConneCtED to a SErVing gEneral pACkET RadIo SeRviCe SUpPort nOde (sGSN) 142 whiCh performs PacKeT switched comMUnIcations wiTh a General packeT raDio serViCe (GprS) netWorK.
NodeS B are mANaged bY the RNCs, rEcEIve infORmation SENt By thE physical layer of a TErMInal 150 (e.g., mobile stAtion, uSeR EqUIPmeNt aNd/or subscrIbEr uniT) Through AN uPLINk, aND transmit data To a terminal 150 THroUgh a doWnLinK. nodes B, Thus, oPeRAte As access poiNts oF the UTRAN For terMInal 150.
The rnCs perfOrm funCtiOns WhicH InClUde AsSIgnINg And MAnaGing radiO rEsOurceS. An Rnc THAt diRecTly mAnageS a Node B is refeRreD to aS A coNtrol rNC (CRnC). ThE CrNC maNages cOmmon RaDio resources. A seRvinG RNC (SRNC), oN thE oTheR hAnd, maNAges deDicAteD radio rEsourceS AssIgNED To The respective termiNaLS. thE CRNC can Be the sAMe As THe SRNC. HoWeVer, When THE termInal DEvIates froM the reGIoN oF the SRNc aNd moveS tO thE reGion oF AnotHer RNC, The CRNC cAn be dIFferent from the srNC. Because the PHySICaL PosiTioNs of various ElemENts iN the umTs neTWork cAn varY, aN InTErface for connecting ThE elemeNts is Necessary. NodeS B and the RNcS ARe connecTed tO EaCH other by an lub iNterfAce. Two RNCs ARe connecTed to Each otheR by an lur iNTErface. An IntErfAce BetWEEn The RNC and a corE NEtwoRk Is referRed To as lu.
FiG. 2 sHowS a sTruCtUre of a radIo access InTeRfAcE prOtocoL Between a TeRmiNaL whIch opERates bAsed oN a 3GPp RaN SPecIficatiON aND A UTRaN. thE radIo aCcEss inTerfACe pRotocol Is horizonTalLY forMeD oF a physiCal layer (PHY), a dAtA link layer, AnD a nEtwork LAYer and is Vertically divided into a cONtrol plAne For trAnsmItting a coNtrOl infoRmaTIon and A user pLane fOr TraNSMittiNG DaTa iNfOrmation. ThE USer Plane Is A regIon to whIch traffic informatIOn oF a user such as vOicE or aN ip pAckET iS TraNsMIttED. the control plane Is a region tO wHIcH control inFOrmAtIon such As an intErfacE Of a netwOrk or mainTenance anD mAnagEMEnt Of a call is tRansmittEd.
In FIG. 2, prOTocol LAyErs caN be DivideD iNto A firsT layer (l1), A seCond lAyer (L2), aNd A third Layer (l3) bAsed on thRee lower layers of an open sYstem iNtercOnnEction (OSI) StaNDarD model welL knoWn in a commuNicAtiOn sysTem.
tHe firSt laYEr (l1) opERates As a pHYsical layER
 mobile switching center ( MSC) 141 w hichper for ms  cir cuit  switched comm u nica tions with the GSM net work.  T h e RN C sare a lso con n ec t e d t oaser vi n ggener alpacketradio serv ice  s upport node( SG SN) 142 wh ich  performs pa cke t swit ch edc ommun ica tions  witha  gener al packet  r a dio se r vice (G P R S)  net work.
Nodes B are ma n aged by the RN Cs, re ce i ve i nfo rma tion sentby  thep hysical la y e r  of a terminal 15 0 (e.g., mo b ile  stati on , u s er equ ipmen ta nd/ or subscrib er u nit) thro ugh an uplink, and tra nsmitdat a t o at er mi nal  1 5 0 t h ro ugh a d ownlink.  N od es B,  thu s , o pera teas a ccess  points of th e U TRAN for  term inal150. 
T he RN Cs per formfu nctions which i nclu de assign ing  a ndma nagin g  radio  re sou rces. A n RNC t h atdi r e c tl y manages a Node B  i s re ferred t o as a co nt r ol RNC ( CR NC) . Th e CRNCmana g es  commonradior es ou rces. A  s erving  R NC(SR NC),o n th e othe r hand,manag e s dedicated ra d io resourcesa ss i g ne d  tothe  respective  ter m inal s. T h eCRN C  canbe th es am e  as the SRNC. Howev er , when  theterminal devi ates fromt h e  regionof t h eS RNC and movesto th e region o f  another  RNC,  the CRN C can bed i fferentfro m t heSRN C .  B ecause the ph y s ical  p osition s o f vario usele men tsin  the UMTS  network  c an  v ar y,an in t erface f or  co nn ect ing t h e elem entsis n ec es s ary . Nodes Ba n d th eRN Cs a reco nnect ed t o  ea ch othe r by an l ubi nter fa ce . Two R NCs are conne ct ed to each  o the r by a n lur inte rface. An interface bet w een the  RN C and  a c ore netwo rkis ref err e d to a s lu.FIG.2sho w s  a st r u ct ure  o f a radioa c ces s int er face  protoc ol between a termi n alwhich operate s b ased o na 3 G PP RAN  s p eci f i cation and a UT RAN. The r ad i oaccess int e rfa ce  protoc ol is h orizo n tally f ormed ofa physica llaye r (PH Y), a data  link la yer, anda  netw o rk  laye r a nd isve rti cally  divid e d i nto a  contr ol  plane  fortr ansmitti ng a control informatio n anda use r p lane fortra n smi tting dat a in formation.  Th e u ser p lan e  is a  reg i on  to which  tra f fic infor m at ion o fa user such a s  vo ice o r a n  IP pa cket  is transmitted.T he control pla ne i s a r egi o n to  w hich control i nfo rm a t ion such  a s an interf ace of a  n e twork  or ma intena nce and m an a gement  ofa c all is tr ans mi t ted.
In  F IG .  2, pr otoc ol  layer s canb e di v i ded into a first  laye r (L1), a s econd  l ayer (L 2 ), a nd a third  layer (L3)  based  onthree  lowerla yers o f a nopen syste m  intercon necti on (OSI )stan dar d mode l we l l  know n in  a  co mmunicati o n  s y st em . 
Th e fi rst l ay er ( L1) opera t es as aphy s ical la ye r
 mobile_switching center_(MSC) 141 which performs_circuit switched_communications_with the_GSM_network. The RNCs_are also connected_to a serving general_packet radio service_support_node (SGSN) 142 which performs packet switched communications with a general packet radio service_(GPRS)_network.
Nodes B_are_managed_by the RNCs, receive information_sent by the physical layer_of a_terminal 150 (e.g., mobile station, user equipment and/or_subscriber_unit) through an_uplink, and transmit data to a terminal 150 through_a downlink. Nodes B, thus, operate_as access points_of_the_UTRAN for terminal 150.
The_RNCs perform functions which include assigning_and managing radio resources. An RNC_that directly manages a Node B is_referred to as a control RNC_(CRNC). The CRNC manages common_radio resources._A serving RNC (SRNC), on_the other hand,_manages dedicated_radio resources assigned_to the respective terminals. The CRNC_can be the_same as the SRNC. However, when_the_terminal deviates from_the_region_of the_SRNC and moves_to_the region_of_another RNC, the CRNC can be_different_from the SRNC. Because the physical positions_of various elements in_the_UMTS network can vary,_an interface for connecting the_elements is necessary. Nodes B and_the RNCs_are connected_to each other by an lub interface. Two RNCs are connected_to each other by an lur_interface. An interface between_the RNC_and_a core network_is_referred to_as lu.
FIG. 2 shows a structure of_a radio_access interface protocol between a terminal_which operates based on_a_3GPP RAN specification and a UTRAN._The radio access interface protocol is_horizontally formed of a physical_layer_(PHY),_a data link layer, and_a network layer and is vertically_divided into a_control plane for transmitting a control information_and_a user plane for transmitting data_information._The user plane is a region_to_which_traffic information of a user_such as voice or an IP_packet is transmitted. The control plane is a region_to which control_information such as an interface_of_a_network or maintenance and management of a call is transmitted.
In_FIG. 2,_protocol layers can_be divided into a first layer (L1), a second layer_(L2), and a third layer (L3) based_on three lower layers of an open system interconnection (OSI) standard_model well known in a communication system.
The first_layer (L1) operates as a physical layer