Patent Publication Number: US-11388583-B2

Title: Method for reporting capability information and dual mode user equipment adapted thereto

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of prior application Ser. No. 16/121,160, filed on Sep. 4, 2018, which has issued as U.S. Pat. No. 10,575,166 on Feb. 25, 2020 and was a continuation of prior application Ser. No. 14/878,652, filed on Oct. 8, 2015, which has issued as U.S. Pat. No. 10,070,304 on Sep. 4, 2018 and was a continuation of application Ser. No. 13/571,735, filed on Aug. 10, 2012, which has issued as U.S. Pat. No. 9,167,416 on Oct. 20, 2015, and which claimed the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 61/521,910, filed on Aug. 10, 2011, U.S. Provisional Application No. 61/524,000, filed on Aug. 16, 2011, U.S. Provisional Application No. 61/531,185, filed on Sep. 6, 2011, U.S. Provisional Application No. 61/552,114, filed on Oct. 27, 2011, and U.S. Provisional Application No. 61/591,385, filed on Jan. 27, 2012, and under 35 U.S.C. § 119(a) of a Korean patent application filed on Aug. 6, 2012 in the Korean Intellectual Property Office and assigned Serial No. 10-2012-0085793, the entire disclosure of each of which is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to dual mode communication. More particularly, the present invention relates to an apparatus and method that allows a dual mode User Equipment (UE) to efficiently report its capability information. 
     2. Description of the Related Art 
     Mobile communication systems have been developed to provide users with communication services while they are moving. With the rapid development of communication technology, mobile communication systems can provide high speed data communication services as well as voice communication. 
     A Long Term Evolution (LTE) system, which is a next generation mobile communication system, is standardized in the 3rd Generation Partnership Project (3GPP). The LTE system implements high speed packet based communication at a data transfer rate of up to 100 Mbps, which is higher than the current data transfer rate. 
     In recent years, the LTE communication system has been combined with other technologies to enhance the transfer rate, and this is called Long Term Evolution-Advanced (LTE-A) system. A technology introduced by the LTE system is carrier aggregation. Carrier aggregation enables one UE to use a number of forward carriers and a number of reverse carriers, compared with the technology of the related are in which a UE performs data transmission/reception only using one forward carrier and one reverse carrier. To support carrier aggregation, a UE can be equipped with additional functions and parts, which are mandatory and optional, respectively. 
     When an evolved Node B (eNB) establishes a wireless channel with the UE, it needs to precisely detect the capability of the UE. To this end, a procedure has been defined in which the UE reports its capabilities to a network. However, the conventional capability information was designed for a single mode UE. Therefore, a system and method is required that allows a dual mode UE to efficiently report its capability information. 
     The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention. 
     SUMMARY OF THE INVENTION 
     Aspects of the present invention are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide an apparatus and method that allows a dual mode User Equipment (UE) to efficiently report its capability information. 
     In accordance with an aspect of the invention, a method for transmitting, by a UE that supports Frequency Division Duplex (FDD) and Time Division Duplex (TDD), UE capability information to an evolved Node B (eNB), is provided. The method includes receiving a message requesting UE capability information from the eNB, generating first capability information and second capability information according to the UE capability information requesting message, and transmitting UE capability information including the first and second capability information to the eNB. The first capability information comprises FDD capability information applicable to an FDD mode or TDD capability information applicable to a TDD mode. The second capability information comprises capability information applicable to both the FDD mode and the TDD mode. 
     In accordance with another aspect of the invention, a UE that supports FDD and TDD is provided. The UE includes a transceiver for receiving a message requesting UE capability information from an eNB, and a controller for generating first capability information and second capability information according to the UE capability information requesting message. The transceiver transmits UE capability information including the first and second capability information to the eNB. The first capability information comprises FDD capability information applicable to an FDD mode or TDD capability information applicable to a TDD mode. The second capability information comprises capability information applicable to both the FDD mode and the TDD mode. 
     In accordance with another aspect of the present invention, a method for receiving, by an eNB, capability information regarding a UE is provided. The method includes transmitting a message requesting UE capability information to the UE, and receiving UE capability information including first capability information and second capability information, in response to the request message, from the UE. The first capability information comprises FDD capability information applicable to an FDD mode or TDD capability information applicable to a TDD mode. The second capability information comprises capability information applicable to both the FDD mode and the TDD mode. 
     In accordance with another aspect of the present invention, an eNB is provided. The eNB includes a transceiver for transmitting a message requesting UE capability information to a UE, and for receiving UE capability information including first capability information and second capability information, in response to the request message, from the UE. The first capability information comprises FDD capability information applicable to an FDD mode or DD capability information applicable to a TDD mode. The second capability information comprises capability information applicable to both the FDD mode and the TDD mode. 
     Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  illustrates a configuration of a Long Term Evolution (LTE) system according to an exemplary embodiment of the present invention; 
         FIG. 2  illustrates a wireless protocol stack of an LTE system according to an exemplary embodiment of the present invention; 
         FIG. 3  illustrates a flowchart that describes a method for establishing a wireless connection between a User Equipment (UE) and an evolved Node B (eNB) according to an exemplary embodiment of the present invention; 
         FIG. 4  illustrates a flowchart that describes a capability information reporting method according to an exemplary embodiment of the present invention; 
         FIG. 5  illustrates a flowchart that describes a method for transmitting capability information by a UE, according to a first exemplary embodiment of the present invention; 
         FIG. 6  illustrates a flowchart that describes a method for reporting capability information by a UE, according to a second exemplary embodiment of the present invention; 
         FIG. 7  illustrates a flowchart that describes a method for reporting capability information via a UE, according to a third exemplary embodiment of the present invention; 
         FIG. 8  illustrates a schematic block diagram of a UE according to an exemplary embodiment of the present invention; and 
         FIG. 9  illustrates a schematic block diagram of an eNB according to an exemplary embodiment of the present invention. 
     
    
    
     Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures. 
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness. 
     The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention is provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. 
     It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces. 
     Detailed descriptions of well-known functions and structures incorporated herein may be omitted to avoid obscuring the subject matter of the invention. Exemplary embodiments of the invention are described below with reference to the accompanying drawings. 
       FIG. 1  illustrates a configuration of a Long Term Evolution (LTE) system according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 1 , the LTE system configures the wireless access network, including evolved Node Bs (eNBs)  105 ,  110 ,  115  and  120 , a Mobility Management Entity (MME)  125 , and a Serving-Gateway (S-GW)  130 . A User Equipment (UE)  135  can access an external network via the eNBs  105 ,  110 ,  115  and  120  and the S-GW  130 . 
     The eNBs  105 ,  110 ,  115  and  120  correspond to conventional Node Bs of the Universal Mobile Telecommunications System (UMTS) system and each eNB controls a number of cells. However, eNBs  105 ,  110 ,  115  or  120 , any of which can provide service to the UE  135  via a wireless channel, perform more complicated functions than a conventional Node B. Since LTE systems provide real time services, such as Voice over Internet Protocol (VoIP), and all user traffic via a shared channel, they require devices that can collect state information, such as a UE buffer state, an available transmission power state, a channel state, etc., in order to schedule, for example, eNBs  105 ,  110 ,  115  and  120 . In order to implement a transfer rate of 100 Mbps, an LTE system employs Orthogonal Frequency Division Multiplexing (OFDM) at a bandwidth of 20 MHz, as a wireless access technology. LTE systems also employ Adaptive Modulation &amp; Coding (AMC) to determine a modulation scheme and a channel coding rate, meeting with the channel state of the UE. The S-GW  130  provides a data bearer and creates or removes data bearers according to the control of the MME  125 . The MME  125  manages the mobility of a UE, controls a variety of functions, and connects to a number of eNBs. 
       FIG. 2  illustrates a wireless protocol stack of an LTE system according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 2 , a UE and an eNB respectively have Packet Data Convergence Protocol (PDCP) layers  205  and  240 , Radio Link Control (RLC) layers  210  and  235 , and Medium Access Control (MAC) layers  215  and  230 . PDCP layers  205  and  240  compress/decompress an IP header. RLC layers  210  and  235  reconfigure a PDCP Packet Data Unit (PDU) in a proper size and perform an ARQ process. MAC layers  215  and  230  connect to a number of RLC layer devices configured in one UE. MAC layers  215  and  230  multiplex RLC PDUs to a MAC PDU, and de-multiplex RLC PDUs from a MAC PDU. PHYsical (PHY) layers  220  and  225  channel-code and modulate data from the upper layers, create OFDM symbols, and transmit them via a wireless channel. In addition, PHY layers  220  and  225  demodulate and channel-decode OFDM symbols received via a wireless channel, and transfer them to the upper layers. 
       FIG. 3  illustrates a flowchart that describes a method for establishing a wireless connection between a UE and an eNB according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 3 , a UE  305  and an eNB  310  can set a variety of functions therebetween according to the capability of the UE  305  and the states of the eNB  310 . 
     For example, the UE  305  and the eNB  310  can set a Discontinuous Reception (DRX) feature in order to allow the UE  305  to prevent excessive battery power from being consumed at step  315 . The UE  305  and the eNB  310  can set a short DRX feature to maximally save the battery power in the UE  305  according to a traffic state at step  320 . The UE  305  and the eNB  310  can set a Semi-Persistent Scheduling (SPS) feature to efficiently support a voice service at step  325 . The UE  305  and the eNB  310  can set a 64 Quadrature Amplitude Modulation (64 QAM) feature to increase the transfer rate of the UE  305  close to the eNB  310  at step  330 . The UE  305  and the eNB  310  can set a UE specific reference signal feature at step  335 . Since none of steps  315  to  335  are mandatory, any or all of them may or may not be performed. 
     In order to set a specific feature to the UE  305  according to states, the eNB  310  needs to determine whether the UE  305  has implemented a corresponding feature and has been subjected to an Inter-Operability Test (TOT). More particularly, the eNB  310  must perform the determination if the UE  305  is a dual mode type of UE that supports both Frequency Division Duplex (FDD) and Time Division Duplex (TDD). A dual mode UE may support a feature in only one mode, or may perform IOT for a feature in only one mode. In that case, the UE  305  needs to report, to the eNB  310 , a mode where a corresponding function for a feature can be executed or a mode where a feature has been subjected to an IOT. Exemplary embodiments of the present invention provide a system and method that can efficiently report information regarding the respective modes. A dual mode UE refers to a type of UE that can support two duplex modes, i.e., FDD and TDD. A duplex mode corresponds to a frequency band, one-to-one. Therefore, a dual mode UE can support at least one FDD band and at least one TDD band. 
       FIG. 4  illustrates a flowchart that describes a capability information reporting method according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 4 , an event occurs in a dual mode UE  405  such that the dual mode UE  405  needs to newly report its capabilities at step  420 . An example of the event is a case where the UE  405  is turned on or the current UE capabilities differ from the previously reported UE capabilities. More particularly, if the UE  405  reports its capabilities while connecting to an FDD network and then moves the connection to a TDD network, or if the UE  405  reports its capabilities while connecting to a TDD network and then moves the connection to an FDD network, it needs to newly report its capabilities. 
     The UE  405  exchanges an RRC CONNECTION SETUP REQUEST message and an RRC CONNECTION SETUP message with an eNB  410  at step  425 . The UE  405  and the eNB  410  establish an RRC connection therebetween to transmit control messages to each other. The RRC CONNECTION SETUP REQUEST message includes an identifier of the UE  405  and a cause for RRC connection setup. The RRC CONNECTION SETUP message includes Signaling Radio Bearer (SRB) setup information, MAC setup information, PHY setup information, etc., SRB refers to wireless bearer for serving an RRC control message. 
     The UE  405  transmits an RRC CONNECTION SETUP COMPLETE message to the eNB  410  at step  430 . The RRC CONNECTION SETUP COMPLETE message includes a Non-Access-Stratum (NAS) message intended for an MME  415 . The NAS message includes information indicating that the capabilities of the UE  405  have been altered. The capabilities of the UE  405  are stored in the MME  415 . When an RRC connection is set up between the UE  405  and the eNB  410 , the MME  415  transmits radio communication related capability of the UE  405  to the eNB  410 . This prevents the UE  405  from reporting its capabilities to the eNB  410  each time that an RRC connection is setup therebetween. Therefore, after the UE  405  moves from an FDD network to a TDD network or from a TDD network to an FDD network, it can report the new UE capability information by transmitting information indicating that the UE capability has been altered to the corresponding network. 
     The eNB  410  transmits the NAS message included in the RRC CONNECTION SETUP COMPLETE message to the MME  415  at step  435 . The NAS message refers to control messages exchanged between the UE  405  and the MME  415 . When the UE  405  is turned on, it transmits an ATTACH REQUEST NAS message to the MME  415 . If the UE  405  that has been turned on newly sets up an RRC connection, it transmits a SERVICE REQUEST NAS message to the MME  415 . If the UE  405  moves to a new tracking area, it transmits a TRACKING AREA UPDATE NAS message to the MME  415 . When the MME  415  receives NAS messages from the UE  405 , it performs a corresponding operation according to the type of NAS message and information included therein. 
     If the MME  415  receives an NAS message including information indicating that the capability information of the UE  405  has been altered, the MME  415  performs an INITIAL CONTEXT SETUP process with respect to the eNB  410 , in order to acquire the new capability information of the UE  405 , at step  440 . During the INITIAL CONTEXT SETUP process, the MME  415  transmits information, required to provide services to the UE  405 , to the eNB  410 . For example, the MME  415  may transmit, to the eNB  410 , information related to security, Quality of Service (QoS), and the like. The MME  415  also transmits UE capability information related to radio communication to the eNB  410  during the INITIAL CONTEXT SETUP process. Since the MME  415  has recognized that the capability of the UE  405  has been altered at step  440 , it does not transmit the UE capability information related to radio communication to the eNB  410 . Therefore, the eNB  410  can start to acquire the UE capability information. That is, when the eNB  410  may not receive the UE capability information during the INITIAL CONTEXT SETUP process, it can acquire the UE capability information via the following steps  445 ,  450 , and  455 . Alternatively, the eNB  410  may perform a process for acquiring UE capability information via preset conditions, e.g., after a preset period of time has elapsed, according to an additional request, etc. 
     The eNB  410  transmits a control UE capability enquiry message to the UE  405 , which instructs the UE  405  to report its capabilities, at step  445 . That is, the eNB  410  instructs the UE  405  to report its capability related to a Radio Access Technology (RAT) via the UE capability enquiry message. Since the eNB  410  requires UE capability related to Evolved UMTS Terrestrial Radio Access Network (E-UTRA) from the UE  405  at step  445 , the UE capability enquiry message may include information that instructs the UE  405  to report E-UTRA capability. 
     The UE  405  transmits its capabilities to the eNB  410  at step  450 . The UE capability information message may include a preset format of UE capability information as shown in Table 1. 
     
       
         
           
               
               
             
               
                 TABLE 1 
               
               
                   
               
             
            
               
                 UE-EUTRA-Capability ::= 
                  SEQUENCE 1 
               
               
                  accessStratumRelease 
                   AccessStratumRelease, 
               
               
                  ue-Category 
                 INTEGER (1..5), 
               
               
                  pdcp-Parameters 
                 PDCP-Parameters, 
               
               
                  phyLayerParameters 
                   PhyLayerParameters, 
               
               
                  rf-Parameters 
                 RF-Parameters, 
               
               
                  measParameters 
                 MeasParameters, 
               
               
                  featureGroupIndicators 
                 BIT STRING (SIZE (32))     OPTIONAL, 
               
            
           
           
               
               
               
            
               
                  interRAT-Parameters 
                   SEQUENCE { 
                   
               
               
                   utraFDD 
                   IRAT-ParametersUTRA-FDD 
                 OPTIONAL, 
               
               
                   utraTDD128 
                   IRAT-ParametersUTRA-TDD128 
                 OPTIONAL, 
               
               
                   utraTDD384 
                   IRAT-ParametersUTRA-TDD384 
                 OPTIONAL, 
               
               
                   utraTDD768 
                   IRAT-ParametersUTRA-TDD768 
                 OPTIONAL, 
               
            
           
           
               
               
            
               
                   geran 
                   IRAT-ParametersGERAN    OPTIONAL, 
               
               
                   cdma2000-HRPD 
                   IRAT-ParametersCDMA2000-HRPD    OPTIONAL, 
               
               
                   cdma2000-1xRTT 
                    IRAT-ParametersCDMA2000-1XRTT 
               
               
                  OPTIONAL 
                   
               
               
                  }, 
                   
               
               
                  nonCriticalExtension 
                   UE-EUTRA-Capability-v920-IEs     OPTIONAL 
               
               
                 } 
               
               
                   
               
            
           
         
       
     
     More detailed information regarding the entities, described in Table 1, may be acquired referring to 3GPP Technical Specification (TS) 36.331. For example, rf-Parameter includes information regarding frequency bands supported by a UE. The frequency bands are defined as shown in Table 2. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                   
                 Uplink (UL)  
                 Downlink (DL)  
                   
               
               
                   
                 operating band 
                 operating band 
                   
               
               
                 E-UTRA 
                 BS receive 
                 BS transmit 
                   
               
               
                 Operating 
                 UE transmit 
                 UE receive 
                 Duplex 
               
               
                 Band 
                 FUL_low-FUL_high 
                 FDL_low-FDL_high 
                 Mode 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 1 
                 1920 MHz-1980 MHz 
                 2110 MHz-2170 MHz 
                 FDD 
               
               
                 2 
                 1850 MHz-1910 MHz 
                 1930 MHz-1990 MHz 
                 FDD 
               
               
                 3 
                 1710 MHz-1785 MHz 
                 1805 MHz-1880 MHz 
                 FDD 
               
               
                 4 
                 1710 MHz-1755 MHz 
                 2110 MHz-2155 MHz 
                 FDD 
               
               
                 5 
                 824 MHz-849 MHz 
                 869 MHz-894 MHz 
                 FDD 
               
               
                 6 
                 830 MHz-840 MHz 
                 875 MHz-885 MHz 
                 FDD 
               
               
                 7 
                 2500 MHz-2570 MHz 
                 2620 MHz-2690 MHz 
                 FDD 
               
               
                 8 
                 880 MHz-915 MHz 
                 925 MHz-960 MHz 
                 FDD 
               
               
                 9 
                 1749.9 MHz-1784.9 MHz 
                 1844.9 MHz-1879.9 MHz 
                 FDD 
               
               
                 10 
                 1710 MHz-1770 MHz 
                 2110 MHz-2170 MHz 
                 FDD 
               
               
                 11 
                 1427.9 MHz-1447.9 MHz 
                 1475.9 MHz-1495.9 MHz 
                 FDD 
               
               
                 12 
                 699 MHz-716 MHz 
                 729 MHz-746 MHz 
                 FDD 
               
               
                 13 
                 777 MHz-787 MHz 
                 746 MHz-756 MHz 
                 FDD 
               
               
                 14 
                 788 MHz-798 MHz 
                 758 MHz-768 MHz 
                 FDD 
               
               
                 15 
                 Reserved 
                 Reserved 
                 FDD 
               
               
                 16 
                 Reserved 
                 Reserved 
                 FDD 
               
               
                 17 
                 704 MHz-716 MHz 
                 734 MHz-746 MHz 
                 FDD 
               
               
                 18 
                 815 MHz-830 MHz 
                 860 MHz-875 MHz 
                 FDD 
               
               
                 19 
                 830 MHz-845 MHz 
                 875 MHz-890 MHz 
                 FDD 
               
               
                 20 
                 832 MHz-862 MHz 
                 791 MHz-821 MHz 
                 FDD 
               
               
                 21 
                 1447.9 MHz-1462.9 MHz 
                 1495.9 MHz-1510.9 MHz 
                 FDD 
               
               
                 . . . 
                   
                   
                   
               
               
                 23 
                 2000 MHz-2020 MHz 
                 2180 MHz-2200 MHz 
                 FDD 
               
               
                 24 
                 1626.5 MHz-1660.5 MHz 
                 1525 MHz-1559 MHz 
                 FDD 
               
               
                 25 
                 1850 MHz-1915 MHz 
                 1930 MHz-1995 MHz 
                 FDD 
               
               
                 . . . 
                   
                   
                   
               
               
                 33 
                 1900 MHz-1920 MHz 
                 1900 MHz-1920 MHz 
                 TDD 
               
               
                 34 
                 2010 MHz-2025 MHz 
                 2010 MHz-2025 MHz 
                 TDD 
               
               
                 35 
                 1850 MHz-1910 MHz 
                 1850 MHz-1910 MHz 
                 TDD 
               
               
                 36 
                 1930 MHz-1990 MHz 
                 1930 MHz-1990 MHz 
                 TDD 
               
               
                 37 
                 1910 MHz-1930 MHz 
                 1910 MHz-1930 MHz 
                 TDD 
               
               
                 38 
                 2570 MHz-2620 MHz 
                 2570 MHz-2620 MHz 
                 TDD 
               
               
                 39 
                 1880 MHz-1920 MHz 
                 1880 MHz-1920 MHz 
                 TDD 
               
               
                 40 
                 2300 MHz-2400 MHz 
                 2300 MHz-2400 MHz 
                 TDD 
               
               
                 41 
                 2496 MHz-2690 MHz 
                 2496 MHz-2690 MHz 
                 TDD 
               
               
                 42 
                 3400 MHz-3600 MHz 
                 3400 MHz-3600 MHz 
                 TDD 
               
               
                 43 
                 3600 MHz-3800 MHz 
                 3600 MHz-3800 MHz 
                 TDD 
               
               
                   
               
            
           
         
       
     
     The UE  405  reports the number of frequency bands that it supports, via rf-Parameters. The frequency bands are classified into an FDD band and a TDD band. If the UE  405  supports only an FDD band, it is a UE that operates in an FDD band. Likewise, if the UE  405  supports only a TDD band, it is a UE that operates in a TDD band. If the UE  405  supports both the FDD and the TDD bands, it is a dual mode UE that operates in both the FDD bands and the TDD bands. 
     The featureGroupIndicators refers to information showing whether the UE  405  is subjected to an IOT with respect to a feature group. The featureGroupIndicators is described in more detail as shown in Table 3. The features included in featureGroupIndicators refer to mandatory features that the UE must implement. For example, if the UE sets bit 3 of Feature Group Indicator (FGI) to ‘1,’ this means that it has implemented 5 bit RLC Unacknowledge Mode (UM) Sequence Number (SN) and 7 bit PDCP SN and has also been subjected to the IOT. 
     
       
         
           
               
               
             
               
                 TABLE 3 
               
               
                   
               
               
                 Index of 
                 Definition 
               
               
                 indicator (bit 
                 (description of the supported functionality, 
               
               
                 number) 
                 if indicator set to one) 
               
               
                   
               
             
            
               
                 1 (leftmost bit) 
                 Intra-subframe frequency hopping for PUSCH scheduled by UL grant 
               
               
                   
                 DCI format 3a (TPC commands for PUCCH and PUSCH with single bit power 
               
               
                   
                 adjustments) 
               
               
                   
                 PDSCH transmission mode 5 
               
               
                   
                 Aperiodic CQI/PMI/RI reporting on PUSCH: Mode 2-0-UE selected subband CQI 
               
               
                   
                 without PMI 
               
               
                   
                 Aperiodic CQI/PMI/RI reporting on PUSCH: Mode 2-2-UE selected subband CQI 
               
               
                   
                 with multiple PMI 
               
               
                 2 
                 Simultaneous CQI and ACK/NACK on PUCCH, i.e. PUCCH format 2a and 2b 
               
               
                   
                 Absolute TPC command for PUSCH 
               
               
                   
                 Resource allocation type 1 for PDSCH 
               
               
                   
                 Periodic CQI/PMI/RI reporting on PUCCH: Mode 2-0-UE selected subband CQI 
               
               
                   
                 without PMI 
               
               
                   
                 Periodic CQI/PMI/RI reporting on PUCCH: Mode 2-1-UE selected subband CQI 
               
               
                   
                 with single PMI 
               
               
                 3 
                 5 bit RLC UM SN 
               
               
                   
                 7 bit PDCP SN 
               
               
                 4 
                 Short DRX cycle 
               
               
                 5 
                 Long DRX cycle 
               
               
                   
                 DRX command MAC control element 
               
               
                 6 
                 Prioritized bit rate 
               
               
                 7 
                 RLC UM 
               
               
                 8 
                 EUTRA RRC_CONNECTED to UTRA CELL_DCH PS handover 
               
               
                 9 
                 EUTRA RRC_CONNECTED to GERAN GSM_Dedicated handover 
               
               
                 10 
                 EUTRA RRC_CONNECTED to GERAN (Packet_) Idle by Cell Change Order 
               
               
                   
                 EUTRA RRC_CONNECTED to GERAN (Packet_) Idle by Cell Change Order with 
               
               
                   
                 NACC (Network Assisted Cell Change) 
               
               
                 11 
                 EUTRA RRC_CONNECTED to CDMA2000 1xRTT CS Active handover 
               
               
                 12 
                 EUTRA RRC_CONNECTED to CDMA2000 HRPD Active handover 
               
               
                 13 
                 Inter-frequency handover (within FDD or TDD) 
               
               
                 14 
                 Measurement reporting event: Event A4-Neighbor &gt; threshold 
               
               
                   
                 Measurement reporting event: Event A5-Serving &lt; threshold1 &amp; Neighbor &gt; 
               
               
                   
                 threshold2 
               
               
                 15 
                 Measurement reporting event: Event B1-Neighbor &gt; threshold 
               
               
                 16 
                 non-ANR related intra-frequency periodical measurement reporting; 
               
               
                   
                 non-ANR related inter-frequency periodical measurement reporting, if the UE has set 
               
               
                   
                 bit number 25 to 1; and 
               
               
                   
                 non-ANR related inter-RAT periodical measurement reporting for UTRAN, GERAN, 
               
               
                   
                 1xRTT or HRPD, if the UE has set bit number 22, 23, 24 or 26 to 1, respectively. 
               
               
                 17 
                 Periodical measurement reporting for SON/ANR 
               
               
                   
                 ANR related intra-frequency measurement reporting events 
               
               
                 18 
                 ANR related inter-frequency measurement reporting events 
               
               
                 19 
                 ANR related inter-RAT measurement reporting events 
               
               
                 20 
                 If bit number 7 is set to 0: 
               
               
                   
                 SRB1 and SRB2 for DCCH + 8x AM DRB 
               
               
                   
                 If bit number 7 is set to 1: 
               
               
                   
                 SRB1 and SRB2 for DCCH + 8x AM DRB 
               
               
                   
                 SRB1 and SRB2 for DCCH + 5x AM DRB + 3x UM DRB 
               
               
                 21 
                 Predefined intra- and inter-subframe frequency hopping for PUSCH with N_sb &gt; 1 
               
               
                   
                 Predefined inter-subframe frequency hopping for PUSCH with N_sb &gt; 1 
               
               
                 22 
                 UTRAN measurements, reporting and measurement reporting event B2 in E-UTRA 
               
               
                   
                 connected mode 
               
               
                 23 
                 GERAN measurements, reporting and measurement reporting event B2 in E-UTRA 
               
               
                   
                 connected mode 
               
               
                 24 
                 1xRTT measurements, reporting and measurement reporting event B2 in E-UTRA 
               
               
                   
                 connected mode 
               
               
                 25 
                 Inter-frequency measurements and reporting in E-UTRA connected mode 
               
               
                   
                 NOTE: The UE setting this bit to 1 and indicating support for FDD and TDD  
               
               
                   
                 frequency bands in the UE capability signaling implements and is tested for FDD  
               
               
                   
                 measurements while the UE is in TDD, and for TDD measurements while  
               
               
                   
                 the UE is in FDD. 
               
               
                 26 
                 HRPD measurements, reporting and measurement reporting event B2 in E-UTRA 
               
               
                   
                 connected mode 
               
               
                 27 
                 EUTRA RRC_CONNECTED to UTRA CELL_DCH CS handover 
               
               
                 28 
                 TTI bundling 
               
               
                 29 
                 Semi-Persistent Scheduling 
               
               
                 30 
                 Handover between FDD and TDD 
               
               
                 31 
                 Undefined 
               
               
                 32 
                 Undefined 
               
               
                   
               
            
           
         
       
     
     If the dual mode UE supports a feature group in FDD and TDD modes and has been subjected to an IOT for the feature group in the modes, it can set FGI for a corresponding feature group to ‘1.’ However, it frequently occurs that, although the dual mode UE has been subjected to an IOT in an FDD mode, it may not have been subjected to the IOT in a TDD mode or vice versa. In that case, the UE  405  cannot determine how to set up FGI for a corresponding feature group. In order to address the problem, the UE  405  reports two sets of FGIs (sets of FGI bits as described in Table 3). One set of FGI indicates whether the UE  405  has been subjected to an IOT in an FDD mode (hereinafter called an FDD FGI set), and the other set of FGI indicates whether the UE  405  has been subjected to an IOT in a TDD mode (hereinafter called a TDD FGI set). 
     When the UE  405  transmits two sets of FGIs via a network, if the eNB  410  and the MME  415  are adapted to a system of the previous release version, they cannot detect part of the received information. If the UE  405  is aware of the release version of the eNB  410  or the network, it can transmit FGI corresponding to the release version. However, since the current system does not provide information to infer the release version of the eNB  410  or the network, sets of FGIs must be defined considering that the eNB  410  may not detect information in a new format. 
     In order to address the problems described above, the field that includes information regarding a set of FGI is determined, referring to a mode of a network (or the eNB  410 ) to which the UE  405  has established a connection. That is, the UE  405  includes one FGI set in a legacy field (or a default field) and the other FGI set in an extension field. In that case, although a network does not detect the extension field, it can detect FGI in a legacy field. Therefore, a corresponding operation can be executed based on the detected information. If a duplex mode of a network where a connection has been currently established differs from that of an FGI set included in a legacy field, the eNB  410  may mistakenly judge the capability of the UE  405 . To address this problem, the UE  405  refers to a mode of a network where a connection has been established at a time point when it reports the capability information, and includes an FGI set of a corresponding mode in a legacy field and an FGI set of the other mode in an extension field. Table 4 describes a conventional Information Entity (IE) for FGI and an IE for FGI of an extension field. It should be understood that Table 4 shows one of the exemplary embodiments. 
     
       
         
           
               
             
               
                 TABLE 4 
               
               
                   
               
             
            
               
                 UE-EUTRA-Capability ::=  SEQUENCE { 
               
            
           
           
               
               
            
               
                  accessStratumRelease 
                 AccessStratumRelease, 
               
               
                  ue-Category 
                 INTEGER (1..5), 
               
               
                  pdcp-Parameters 
                 PDCP-Parameters, 
               
               
                  phyLayerParameters 
                 PhyLayerParameters, 
               
               
                  rf-Parameters 
                 RF-Parameters, 
               
               
                  measParameters 
                 MeasParameters, 
               
               
                  featureGroupIndicators 
                 BIT STRING (SIZE (32)) == featureGroupIndicator, applied to 
               
            
           
           
               
            
               
                 the existing IE and the current duplex mode == 
               
            
           
           
               
               
            
               
                  interRAT-Parameters 
                 SEQUENCE { 
               
               
                   utraFDD 
                  IRAT-ParametersUTRA-FDD 
               
               
                  OPTIONAL, 
                   
               
               
                   utraTDD128 
                  IRAT-ParametersUTRA-TDD128 OPTIONAL, 
               
               
                   utraTDD384 
                  IRAT-ParametersUTRA-TDD384 OPTIONAL, 
               
               
                   utraTDD768 
                  IRAT-ParametersUTRA-TDD768 OPTIONAL, 
               
               
                   geran 
                  IRAT-ParametersGERAN    OPTIONAL, 
               
               
                   cdma2000-HRPD 
                  IRAT-ParametersCDMA2000-HRPD 
               
               
                  OPTIONAL, 
                   
               
               
                   cdma2000-1xRTT 
                   IRAT-ParametersCDMA2000-1XRTT 
               
               
                  OPTIONAL 
                   
               
               
                  }, 
                   
               
               
                  nonCriticalExtension 
                 UE-EUTRA-Capability-v920-IEs OPTIONAL 
               
               
                 } 
                   
               
               
                 UE-EUTRA-Capability-v11xy-IEs ::= 
                 SEQUENCE { 
               
               
                  featureGroupIndicators 
                  BIT STRING (SIZE (32)) == featureGroupIndicator, 
               
            
           
           
               
            
               
                 applied to newly extended IE and a duplex mode that differs from the current duplex mode == 
               
               
                 } 
               
               
                   
               
            
           
         
       
     
     If the dual mode UE  405  has set up a connection with an FDD network (i.e., if the UE  405  is connected to the eNB  410  operating in an FDD band), it may include an FDD FGI set in a legacy field and a TDD FGI set in an extension field. Alternatively, if the dual mode UE  405  has set up a connection with a TDD network (i.e., if the UE  405  is connected to the eNB  410  operating in a TDD band), it may include a TDD FGI set in a legacy field and an FDD FGI set in an extension field. 
     The eNB  410  includes the UE capability information, received at step  450 , in a UE CAPABILITY INFO INDICATION control message and transmits the message to the MME  415  at step  455 . The MME  415  stores the received UE capability information and uses it during the INITIAL CONTEXT SETUP process. The eNB  410  can determine setting information that will be applied to the UE  405 , referring to the UE capability information transmitted from the UE  405 . 
       FIG. 5  illustrates a flowchart that describes a method for transmitting capability information by a UE, according to a first exemplary embodiment of the invention. 
     Referring to  FIG. 5 , an event occurs in a dual mode UE  405  such that it needs to newly report its capability information to an eNB  410  at step  505 . The UE  405  performs an RRC CONNECTION SETUP process with respect to the eNB  410  at step  510 . When the UE  405  establishes an RRC connection with the eNB  410 , it generates an RRC CONNECTION SETUP COMPLETE message and transmits it to the eNB  410  at step  515 . The RRC CONNECTION SETUP COMPLETE message may include NAS messages, such as ATTACH REQUEST, Tracking Area Update (TAU), SERVICE REQUEST, and the like. The UE  405  may include information indicating that the UE radio capability has been altered in the NAS message. 
     After transmitting the RRC CONNECTION SETUP COMPLETE message to the eNB  410 , the UE  405  may execute corresponding functions at step  520 . In order to acquire new UE capability information regarding the UE  405 , the eNB  410  may transmit a UE capability enquiry message to the UE  405  as described above, referring to  FIG. 4 . The message may include information that instructs the UE  405  to report E-UTRA capability. 
     When the UE  405  receives the message from the eNB  410  at step  520 , it determines whether the mode of the current network is an FDD or TDD mode at step  525 . That is, the UE  405  determines whether the operating band of the current cell is an FDD or TDD band. Alternatively, the UE  405  determines whether its current operating band is an FDD or TDD band. Since the current operating band of the UE  405  always matches the operating band of the current cell, the two determining processes are substantially identical to each other. Alternatively, the UE  405  may have previously determined the mode of the current network at step  505 . That is, the UE  405  may execute the processes following step  525 , based on the mode of the network at a time point that it needs to report the capability information. 
     If it is determined that the mode of the current network is an FDD mode at step  525 , the UE  405  includes an FDD FGI set (i.e., information showing whether an IOT test has been performed in an FDD mode) in a legacy field (which can be understood by a conventional network), and a TDD FGI set (i.e., information showing whether an IOT test has been performed in a TDD mode) in an extension field (which can be understood by a network of a new release version, e.g., Release 10 or Release 11) at step  530 . The UE  405  may perform the processes, taking into consideration whether an FDD FGI set and a TDD FGI set are identical to each other. That is, if the FDD FGI set and the TDD FGI set differ from each other, the UE  405  reports them to the eNB  410 . If the FDD FGI set and the TDD FGI set are identical to each other, the UE  405  reports one of them to the eNB  410 . Alternatively, the UE  405  may perform the processes, taking into consideration whether the FDD capability information is identical to the TDD capability information. For example, if the FDD capability information (e.g., the FDD FGI set) differs from the TDD capability information (e.g., the TDD FGI set), the UE  405  reports the two sets to the eNB  410 . If the FDD capability information (e.g., the FDD FGI set) is identical to the TDD capability information (e.g., the TDD FGI set), the UE  405  may not include an extension field. Therefore, if the eNB  410  receives capability information including one FGI set, it concludes that the received capability information can be applied to both TDD and FDD. 
     On the contrary, if it is determined that the mode of the current network is a TDD mode at step  525 , the UE  405  includes a TDD FGI set in a legacy field (which can be understood by a conventional network), and an FDD FGI set (i.e., information showing whether an IOT test has been performed in an FDD mode) in an extension field (which can be understood by a network of a new release version, e.g., Release 10 or Release 11) at step  535 . The UE  405  may perform the processes, taking into consideration whether an FDD FGI set and a TDD FGI set are identical to each other. That is, if the FDD FGI set and the TDD FGI set differ from each other, the UE  405  reports them to the eNB  410 . If the FDD FGI set and the TDD FGI set are identical to each other, the UE  405  reports one of them to the eNB  410 . Alternatively, the UE  405  may perform the processes, taking into consideration whether the FDD capability information is identical to the TDD capability information. For example, if the FDD capability information (e.g., the FDD FGI set) differs from the TDD capability information (e.g., the TDD FGI set), the UE  405  reports the two sets to the eNB  410 . If the FDD capability information (e.g., the FDD FGI set) is identical to the TDD capability information (e.g., the TDD FGI set), the UE  405  may not include an extension field. Therefore, if the eNB  410  receives capability information including one FGI set, it concludes that the received capability information can be applied to TDD and FDD. 
     The UE  405  transmits the UE capability information, including information generated at steps  530  or  535 , to the eNB  410  at step  540 . 
     The UE  405  can report the FGI sets and the other information. For example, the UE  405  may report information related to other capabilities that depend on whether an IOT test is performed or whether it can be supported (e.g., a feature indicating whether it can be supported via phyLayerParameters or interRAT-Parameters). The UE  405  may also report information related to the other capabilities, information regarding FDD, and information regarding TDD. During this process, the UE  405  includes capability information, supported in a mode of the current network, in a legacy related-field, and also capability information, supported in a mode other than the mode of the current network, in an extension field, and then reports them. 
       FIG. 6  illustrates a flowchart that describes a method for reporting capability information by a UE according to a second exemplary embodiment of the present invention. 
     A conventional UE reports all frequency bands that it supports via rf-Parameters, and also reports a measurement gap requirement for respective frequency bands via measParameters. 
     In the second exemplary embodiment of the invention, the UE  405  determines information to be included in rf-Parameters and measParameters, considering a mode of a current serving network. If the UE  405  is connected to an FDD network, it reports FDD bands and the measurement gap requirement for the FDD bands, via a legacy field, e.g., rf-Parameters and measParameters. The UE  405  reports information regarding a mode, different from that of a current serving network, via an extension field (e.g., rf-Parameters and measParameters defined as a lower field of a UE-EUTRA-Capability-v11xy-IEs field). 
     As such, since a UE according to exemplary embodiments of the present invention operates in an FDD band and a TDD band separately, it can communicate with an eNB of the previous release without malfunction. That is, if an FDD band and a TDD band were reported to a legacy field but an FGI reports information regarding only one of the two bands, an eNB of the previous release may make a mistake in determining a feature group with respect to the mobility. For example, FGI 25 is related to inter-frequency for E-UTRA bands. Although the UE  405  has set FGI 25 of featureGroupIndicators of UE-EUTRA-Capability as a legacy related-field to ‘1’ in order to indicate that it has been subjected to an IOT for inter-frequency measurement with respect to the FDD bands, if the FDD bands and TDD bands are reported via rf-Parameters of the legacy related-field, the eNB of the previous release may mistakenly determine that the UE  405  has been subjected to an IOT for inter-frequency measurement with respect to all bands including FDD bands and TDD bands. Therefore, exemplary embodiments of the invention report bands with respect to modes. 
     Referring to  FIG. 6 , an event occurs in a dual mode UE  405  such that it needs to newly report its capability information at step  605 . The UE  405  performs an RRC CONNECTION SETUP process with respect to the eNB at step  610 . When the UE  405  establishes an RRC connection with the eNB, it generates an RRC CONNECTION SETUP COMPLETE message and transmits the message to the eNB  410  at step  615 . The message may include NAS messages, such as ATTACH REQUEST, Tracking Area Update (TAU), SERVICE REQUEST, and the like. The UE  405  may include information indicating that the UE radio capability has been altered in the NAS message. 
     After transmitting an RRC CONNECTION SETUP COMPLETE message to the eNB  410 , the UE  405  may execute corresponding functions at step  620 . In order to acquire new UE capability information regarding the UE  405 , the eNB  410  may transmit a UE capability enquiry message to the UE  405  as described above, referring to  FIG. 4 . The message may include information that instructs the UE  405  to report E-UTRA capability. 
     When the UE  405  receives the message from the eNB  410  at step  620 , it determines whether the mode of the current network is an FDD or TDD mode at step  625 . That is, the UE  405  determines whether the operating band of the current cell is an FDD or TDD band. Alternatively, the UE  405  determines whether its current operating band is an FDD or TDD band. Since the current operating band of the UE  405  always matches the operating band of the current cell, the two determining processes are substantially identical to each other. Alternatively, the UE  405  may have previously determined the mode of the current network at step  605 . That is, the UE  405  may execute the processes following step  525 , based on the mode of the network at a time point that it needs to report the capability information. 
     If it is determined that the mode of the current network is an FDD mode at step  625 , the UE  405  includes an FDD FGI set, FDD bands that it supports, a measurement gap requirement for the FDD bands, etc., in a legacy field (which can be understood by a conventional network), and also a TDD FGI set (i.e., information showing whether an IOT test has been performed in a TDD mode), TDD bands that it supports, a measurement gap requirement for the TDD bands, etc., in an extension field at step  630 . 
     Table 5 describes an example of an IE that can be used at step  630 . 
     
       
         
           
               
               
             
               
                 TABLE 5 
               
               
                   
               
             
            
               
                 UE-EUTRA-Capability ::= 
                   SEQUENCE { 
               
               
                 accessStratumRelease 
                 AccessStratumRelease, 
               
               
                 ue-Category 
                 INTEGER (1..5), 
               
               
                 pdcp-Parameters 
                 PDCP-Parameters, 
               
               
                 phyLayerParameters 
                 PhyLayerParameters, 
               
            
           
           
               
               
               
            
               
                 rf-Parameters 
                 RF-Parameters, 
                 == Only FDD bands are included == 
               
               
                 measParameters 
                 MeasParameters, 
                 == measurement gap requirement for FDD 
               
            
           
           
               
               
            
               
                 bands == 
                   
               
               
                 featureGroupIndicators 
                 BIT STRING (SIZE (32)) == featureGroupIndicator of FDD == 
               
               
                 interRAT-Parameters 
                 SEQUENCE { 
               
               
                 utraFDD 
                 IRAT-ParametersUTRA-FDD     OPTIONAL, 
               
               
                 utraTDD128 
                 IRAT-ParametersUTRA-TDD128 OPTIONAL, 
               
               
                 utraTDD384 
                 IRAT-ParametersUTRA-TDD384 OPTIONAL, 
               
               
                 utraTDD768 
                 IRAT-ParametersUTRA-TDD768 OPTIONAL, 
               
               
                 geran 
                 IRAT-ParametersGERAN    OPTIONAL, 
               
               
                 cdma2000-HRPD 
                 IRAT-ParametersCDMA2000-HRPD  OPTIONAL, 
               
               
                 cdma2000-1xRTT 
                   IRAT-ParametersCDMA2000-1XRTT  OPTIONAL 
               
               
                 }, 
                   
               
               
                 nonCriticalExtension 
                 UE-EUTRA-Capability-v920-IEs OPTIONAL 
               
               
                 } 
                   
               
            
           
           
               
            
               
                 UE-EUTRA-Capability-v11xy-IEs ::= SEQUENCE { 
               
            
           
           
               
               
            
               
                 if-Parameters 
                   RF-Parameters,     == Only TDD bands are included 
               
               
                  == 
                   
               
               
                 measParameters 
                   MeasParameters,    == measurement gap requirement 
               
               
                 for TDD bands == 
                   
               
               
                 featureGroupIndicators 
                   BIT STRING (SIZE (32)) == featureGroupIndicator of TDD 
               
               
                 == 
                   
               
               
                 } 
               
               
                   
               
            
           
         
       
     
     Mobility-related bits of the FGI bits, e.g., FGI 8, 9, 10, 11, 25, etc., have different meanings according to positions where featureGroupIndicators are stored and according to information included in the stored rf-Parameters, as follows.
         Mobility-related FGIs of the featureGroupIndicators in a legacy field indicate the requirement of an IOT with respect to only the bands included in the rf-Parameters of a legacy field.   Mobility-related FGIs of the featureGroupIndicators in an extension field report the requirement of an IOT with respect to items that were not reported via FGI of a legacy related-field, considering bands included in the rf-Parameters of an extension field and bands included in the rf-Parameters of a legacy related-field.       

     For example, if the UE  405  locates, in a legacy field, an rf-Parameter including an FDD band (or a TDD band at step  635 ) and an FGI related to an FDD (or TDD) mode, and also, in an extension field, an rf-Parameter including a TDD band (or an FDD band) and an FGI related to a TDD (or an FDD at step  635 ) mode,
         a mobility-related FGI bit in a legacy field, e.g., FGI 25, indicates the requirement of an IOT test for the following case.
           the requirement of an IOT test for inter-frequency measurement with respect to an FDD (or TDD at step  635 ) band in an FDD (or TDD at step  635 ) band.   
           a mobility-related FGI bit in an extension field, e.g., FGI 25, indicates the requirement of an IOT test for the following cases (i.e., of the four total cases, reports are made regarding three cases except for one case that was reported via a legacy related-field).
           the requirement of an IOT test as to whether inter-frequency measurement is performed with respect to a TDD (or FDD at step  635 ) band in an FDD (or TDD at step  635 ) band.   the requirement of an IOT test as to whether inter-frequency measurement is performed with respect to a TDD (or FDD at step  635 ) band in a TDD (or FDD at step  635 ) band.   the requirement of an IOT test as to whether inter-frequency measurement is performed with respect to an FDD (or TDD at step  635 ) band in a TDD (or FDD at step  635 ) band.   
               

     Meanwhile, if it is determined that the mode of the current network is a TDD mode at step  625 , the UE  405  includes a TDD FGI set (i.e., information showing whether an IOT test has been performed in a TDD mode), TDD bands that it supports, a measurement gap requirement for the TDD bands, etc., in a legacy field (which can be understood by a conventional network), and also an FDD FGI set (i.e., information showing whether an IOT test has been performed in an FDD mode), FDD bands that it supports, measurement gap requirement for the FDD bands, etc., in an extension field at step  635 . 
     The UE  405  transmits the UE capability information, including information generated at steps  630  or  635 , to the eNB  410  at step  640 . 
       FIG. 7  illustrates a flowchart that describes a method for reporting capability information via a UE according to a third exemplary embodiment of the present invention. 
     The third exemplary embodiment of the present invention provides a method for supporting features and FGI sets and indicating the requirement of an IOT test in respective duplex modes. UE-EUTRA-Capability includes an FGI bit, parameters related to bands that the UE supports (rf-Parameters), a parameter related to a peak data rate of the UE (ue-Category), parameters related to physical layer capability (phyLayerParameters), parameters related to other radio access technology (interRAT-Parameters), etc. In the third exemplary embodiment of the present invention, UE-EUTRA-Capability is managed as the following three examples.
         UE-EUTRA-Capability 1: this refers to UE-EUTRA-Capability that is determined considering only an FDD band. That is, the UE  405  includes only FDD bands that it supports in the rf-Parameter and configures an FGI bit of an FGI set in such a way to indicate whether a corresponding feature group is subjected to an IOT test in an FDD band. When the UE  405  reports whether it supports optional features, e.g., a number of features included in phyLayerParameters, it reports only the features that are supported in FDD bands and have been subjected to an IOT test.   UE-EUTRA-Capability 2: this refers to UE-EUTRA-Capability that is determined considering only a TDD band. That is, the UE  405  includes only TDD bands that it supports in the rf-Parameter and configures an FGI bit of an FGI set in such a way to indicate whether a corresponding feature group is subjected to an IOT test in a TDD band. When the UE  405  reports whether it supports optional features, e.g., a number of features included in phyLayerParameters, it reports only the features that are supported in TDD bands and have been subjected to an IOT test.   UE-EUTRA-Capability 3: this refers to UE-EUTRA-Capability that is determined considering both FDD and TDD bands. That is, the UE  405  includes all bands that it supports in the rf-Parameter and configures an FGI bit in such a way to indicate whether a corresponding feature group is subjected to an IOT test in one or more FDD bands and one or more TDD bands, from among all the bands that it supports. When the UE  405  reports whether it supports optional features, e.g., a number of features included in phyLayerParameters, it reports the features that are supported in both FDD and TDD bands and have been subjected to an IOT test.       

     The three capabilities described above may be identical to each other or differ from each other. If IOT environments for FDD and TDD may differ from each other or different types of features with respect to FDD and TDD are supported, the capabilities have different values respectively. 
     The UE  405  determines capability information to be reported, according to a mode of a network at a time point that it transmits UE capability information. For example, the UE  405  reports UE-EUTRA-Capability 1 and UE-EUTRA-Capability 3 via an FDD network and UE-EUTRA-Capability 2 and UE-EUTRA-Capability 3 via a TDD network. 
     Referring to  FIG. 7 , an event occurs in a dual mode UE  405  such that it needs to newly report its capability information at step  705 . The UE  405  performs an RRC CONNECTION SETUP process with respect to the eNB  410  at step  710 . When the UE  405  establishes an RRC connection with the eNB  410 , it generates an RRC CONNECTION SETUP COMPLETE message and transmits it to the eNB  410  at step  715 . The message may include NAS messages, such as ATTACH REQUEST, Tracking Area Update (TAU), SERVICE REQUEST, and the like. The UE  405  may include information indicating that the UE radio capability has been altered in the NAS message. 
     After transmitting the RRC CONNECTION SETUP COMPLETE message to the eNB  410 , the UE  405  may execute corresponding functions at step  720 . In order to acquire new UE capability information regarding the UE  405 , the eNB  410  may transmit a UE capability enquiry message to the UE  405  as described above, referring to  FIG. 4 . The message may include information that instructs the UE  405  to report EUTRA capability. 
     When the UE  405  receives the message from the eNB  410  at step  720 , it determines whether the mode of the current network is an FDD or TDD mode at step  725 . That is, the UE  405  determines whether the operating band of the current cell is an FDD or TDD band. Alternatively, the UE  405  determines whether its current operating band is an FDD or TDD band. Since the current operating band of the UE  405  always matches the operating band of the current cell, the two determining processes are substantially identical to each other. Alternatively, the UE  405  may have previously determined the mode of the current network at step  705 . That is, the UE  405  may execute the processes, based on the mode of the network at a time point that it needs to report the capability information. 
     If it is determined that the mode of the current network is an FDD mode at step  725 , the UE  405  generates the UE capability information message at step  730 . The UE capability information message includes, of the EUTRA-Capability-1, serving as capability information applicable to FDD, and EUTRA-Capability-2, serving as capability information applicable to TDD, UE-EUTRA-Capability-1, serving as capability information applicable to FDD corresponding to a mode of the current network, in a legacy field, and UE-EUTRA-Capability-3, serving as capability information applicable to FDD and TDD, in an extension field. If capability information applicable to one duplex mode (i.e., EUTRA-Capability-1 or EUTRA-Capability-2) differs from capability information commonly applicable to the two duplex modes (i.e., EUTRA-Capability-3), the UE  405  reports the information regarding the two capabilities. On the contrary, if capability information applicable to one duplex mode (i.e., EUTRA-Capability-1 or EUTRA-Capability-2) is identical to capability information commonly applicable to the two duplex modes (i.e., EUTRA-Capability-3), the UE  405  reports information regarding one of the two capabilities. Therefore, if the eNB  410  receives capability information including one FGI set, it concludes that the received capability information can be applied to both TDD and FDD. 
     On the contrary, if it is determined that the mode of the current network is a TDD mode at step  725 , the UE  405  generates the UE capability information message at step  735 . The UE capability information message includes, of the EUTRA-Capability-1, serving as capability information applicable to FDD, and EUTRA-Capability-2, serving as capability information applicable to TDD, UE-EUTRA-Capability-2, serving as capability information applicable to TDD corresponding to a mode of the current network, in a legacy field, and UE-EUTRA-Capability-3, serving as capability information applicable to FDD and TDD, in an extension field. If capability information applicable to one duplex mode (i.e., EUTRA-Capability-1 or EUTRA-Capability-2) differs from capability information commonly applicable to the two duplex modes (i.e., EUTRA-Capability-3), the UE  405  reports the information regarding the two capabilities. On the contrary, if capability information applicable to one duplex mode (i.e., EUTRA-Capability-1 or EUTRA-Capability-2) is identical to capability information commonly applicable to the two duplex modes (i.e., EUTRA-Capability-3), the UE  405  reports information regarding one of the two capabilities. 
     The UE  405  transmits the UE capability information, including information generated at steps  730  or  735 , to the eNB  410  at step  740 . 
       FIG. 8  illustrates a schematic block diagram of a UE according to an exemplary embodiment of the present invention. 
     Referring to  FIG. 8 , the UE  405  includes a transceiver  805 , a controller  810 , a multiplexer and demultiplexer  820 , a control message processor  835 , and upper layer devices  825  and  830 . 
     The transceiver  805  receives data and control signals via the forward channel of a serving cell and transmits data and control signals via the reverse channel. 
     The multiplexer and demultiplexer  820  multiplexes data from the control message processor  835  or the upper layer devices  825  and  830  or de-multiplexes data from the transceiver  805 , and transfers the processed data to the control message processor  835  or the upper layer devices  825  and  830 . 
     The control message processor  835  refers to an RRC layer device. The control message processor  835  processes control messages transmitted from eNB  410  and performs corresponding operations. For example, the control message processor  835  receives an RRC control message, and transfers, if the RRC control message includes DRX-related information or SPS-related information, the included information to the controller  810 . The control message processor  835  processes the control messages so that the UE  405  can report the capability information as described above referring to  FIGS. 4 to 7 . The control message processor  835  can generate UE capability information according to the exemplary embodiments described above. The exemplary embodiments may be modified in such a way that the controller  810  generates UE capability information. 
     The upper layer devices  825  and  830  may be configured according to types of services. For example, the upper layer devices  825  and  830  process data, generated when user services such as File Transfer Protocol (FTP) or Voice over Internet Protocol (VoIP) services are provided, and transfer them to the multiplexer and demultiplexer  820 . The upper layer devices  825  and  830  may also process data, from the multiplexer and demultiplexer  820 , and transfer data to the upper layer service application. 
     The controller  810  receives a scheduling command via the transceiver  805 , identifies the reverse grants, and controls the transceiver  805  and the multiplexer and demultiplexer  820  to transmit them as a proper transmission resource, in the reverse direction, at a proper time point. The controller  810  also sets up functions, referring to setting information transmitted from the control message processor  835 . The controller  810  can control operations so that the UE  405  can report its capability information as described above referring to  FIGS. 4 to 7 . 
       FIG. 9  illustrates a schematic block diagram of an eNB according to an exemplary embodiment of the present invention 
     Referring to  FIG. 9 , the eNB  410  includes a transceiver  905 , a controller  910 , a multiplexer and demultiplexer  920 , a control message processor  935 , upper layer devices  925  and  930 , and a scheduler  915 . 
     The transceiver  905  transmits data and control signals via the forward carriers and receives data and control signals via the reverse carriers. 
     The multiplexer and demultiplexer  920  multiplexes data from the control message processor  935  or the upper layer devices  925  and  930  or de-multiplexes data from the transceiver  905 , and transfers the processed data to the control message processor  935 , the upper layer devices  925  and  930 , or the controller  910 . 
     The control message processor  935  processes control messages from the UE  405  and performs corresponding operations. The control message processor  935  also generates control messages to be transmitted to the UE  405  and transfers them to the lower layer. The control message processor  935  generates a UE CAPABILITY ENQUIRY message to be transmitted to the UE  405 , processes UE CAPABILITY INFORMATION transmitted from the UE  405 , and determines a function to set the UE  405  based on the processed information. The control message processor  935  generates an RRC CONNECTION RECONFIGURATION message based on the determination and transfers it to the multiplexer and demultiplexer  920 . 
     The upper layer devices  925  and  930  may be configured according to bearers. The upper layer devices  925  and  930  configure data, transmitted from S-GW  130  or the other eNB, to RLC PDU, and transfer it to the multiplexer-demultiplexer  920 . The upper layer devices  925  and  930  configure RLC PDU, transmitted from the multiplexer-demultiplexer  920 , to PDCP SDU, and transfer it to the S-GW  130  or the other eNB. 
     The scheduler  915  allocates transmission resources to the UE  405  at a proper time point, considering the buffer state, the channel state, etc. The scheduler  915  processes signals transmitted from or to the UE. 
     The controller  910  controls operations of the eNB  410  to receive UE capability information from the UE  405  according to one of the exemplary embodiments as described referring to  FIGS. 4 to 7 . 
     More particularly, the eNB  410  receives UE capability information, extracts information regarding a corresponding capability, considering the mode where the UE capability is reported, and accordingly communicates with the UE  405 . 
     As described above, the system and method according to exemplary embodiments of the invention can allow a dual mode UE to efficiently report its capability information. 
     In addition, it should be understood that the exemplary processes and operations of the mobile device, described above, can be performed via computer programming instructions. These computer programming instructions can be installed in processors of data processing equipment that can be programmed, special computers, or universal (e.g., general purpose) computers. The instructions, performed via the processors of data processing equipment or the computers, can generate means that perform functions described in blocks of the flowchart. In order to implement functions in a particular mode, the computer programming instructions can also be stored in a computer available memory or computer readable memory that can support computers or data processing equipment that can be programmed. Therefore, the instructions, stored in the computer available memory or computer readable memory, can be installed to the products, and perform the functions therein, described in the blocks of the flowchart therein. In addition, since the computer programming instructions can also be installed to computers or data processing equipment that can be programmed, they can create processes that perform a series of operations therein, described in the blocks of the flowchart therein. 
     The blocks of the flowcharts refer to parts of codes, segments or modules that include one or more executable instructions to perform one or more logic functions. It should be noted that the functions described in the blocks of the flowcharts may be performed in a different order from the exemplary embodiments described above. For example, the functions described in two adjacent blocks may be performed at the same time or in reverse order. 
     In the exemplary embodiments, the terminology, component ‘˜unit,’ refers to a software element or a hardware element such as a Field Programmable Gate Array (FPGA), an Application Specific Integrated Circuit (ASIC), etc., and performs a corresponding function. It should be, however, understood that the component ‘˜unit’ is not limited to a software or hardware element. The component ‘˜unit’ may be implemented in storage media that can be designated by addresses. The component ‘˜unit’ may also be configured to regenerate one or more processors. For example, the component ‘˜unit’ may include various types of elements (e.g., software elements, object-oriented software elements, class elements, task elements, etc.), segments (e.g., processes, functions, achieves, attribute, procedures, sub-routines, program codes, etc.), drivers, firmware, micro-codes, circuit, data, data base, data structures, tables, arrays, variables, etc. Functions provided by elements and the components ‘˜units’ may be formed by combining the small number of elements and components ‘˜units’ or may be divided into additional elements and components ‘˜units.’ In addition, elements and components ‘˜units’ may also be implemented to regenerate one or more CPUs in devices or security multi-cards. 
     The terms or words described in the description and the claims should not be limited by a general or lexical meaning, but instead should be analyzed as a meaning and a concept through which the inventor defines and describes the invention, to comply with the idea of the invention. Therefore, one skilled in the art will understand that the exemplary embodiments disclosed in the description and configurations illustrated in the drawings are only exemplary embodiments, and that there may be various modifications, alterations, and equivalents thereof to replace the exemplary embodiments at the time of filing this application. 
     While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims and their equivalents.