Abstract:
A method and an apparatus for feedback based on information transmitted between base stations (or base stations) through cooperative communication are provided. The method includes receiving, from the second base station, a first message for requesting a channel state information (CSI) report, and transmitting, to the second base station, a second message including the CSI report, based on the first message. The present disclosure relates to a pre-5th-generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-generation (4G) communication system such as long term evolution (LTE).

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
       [0001]    This application claims the benefit under 35 U.S.C. §119(e) of a U.S. provisional patent application filed on Aug. 1, 2014 in the U.S. Patent and Trademark Office and assigned Ser. No. 62/032,264, the entire disclosure of which is hereby incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to wireless communication systems. More particularly, the present disclosure relates to a method and an apparatus for providing feedback based on information transmitted between base transceiver stations through cooperative communication. 
       BACKGROUND 
       [0003]    To meet the demand for wireless data traffic having increased since deployment of fourth generation (4G) communication systems, efforts have been made to develop an improved fifth generation (5G) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘Beyond 4G Network’ or a ‘Post long term evolution (LTE) System’. 
         [0004]    The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems. 
         [0005]    In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation, and the like. 
         [0006]    In the 5G system, Hybrid frequency-shift keying (FSK) and quadrature amplitude modulation (QAM) Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed. 
         [0007]    Therefore, a need exists for a method and an apparatus for providing feedback based on information transmitted between base transceiver stations through cooperative communication. 
         [0008]    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 disclosure. 
       SUMMARY 
       [0009]    Aspects of the present disclosure 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 disclosure is to provide a method and an apparatus for a first base station (eNB) to request channel state information (CSI) from a second base station (eNB) in order to make inter-eNB cooperative communication (cooperative communication between base stations). 
         [0010]    Another aspect of the present disclosure is to provide a method and an apparatus for transmitting, by using enhanced-relative narrowband transmission power (RNTP), information indicating whether a second base station performs the allocation of resources to comply with resource allocation information that a first base station has generated, based on channel state information (CSI), and transmitted to the second base station, when the second base station performs allocation of resources is provided. 
         [0011]    In accordance with an embodiment of the present disclosure, a method for feeding back to a second base station by a first base station in a communication system is provided. The method includes receiving, from the second base station, a first message for requesting a CSI report, and transmitting, to the second base station, a second message including the CSI report, based on the first message. 
         [0012]    In accordance with another embodiment of the present disclosure, a method for supporting feeding back of a first base station by a second base station in a communication system is provided. The method includes transmitting, to the first base station, a first message for requesting a CSI report, and receiving, from the first base station, a second message including the CSI report based on the first message. 
         [0013]    In accordance with another embodiment of the present disclosure, the present disclosure provides a first base station that provides feedback to a second base station in a wireless communication system comprising a transceiver configured to perform transmission/reception of signals, and a controller configured to receive, from the second base station, a first message for requesting a CSI report, and transmit, to the second base station, a second message including the CSI report, based on the first message. 
         [0014]    In accordance with another embodiment of the present disclosure, the present disclosure provides a second base station that supports feedback of a first base station in a wireless communication system comprising a transceiver configured to perform transmission/reception of signals, and a controller configured to transmit, to the first base station, a first message for requesting a CSI report, and receive, from the first base station, a second message including the CSI report based on the first message. 
         [0015]    Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the present disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The above and other aspects, features, and advantages of certain embodiments of the present disclosure will be more apparent from the following description in conjunction with the accompanying drawings, in which: 
           [0017]      FIG. 1  is a diagram illustrating a general wireless communication system according to an embodiment of the present disclosure; 
           [0018]      FIG. 2  is a diagram illustrating a case where radio access points have one or more overlapping coverage area according to an embodiment of the present disclosure; 
           [0019]      FIG. 3  is a diagram illustrating a configuration of transmission and reception of coordinated information between radio access points according to an embodiment of the present disclosure; 
           [0020]      FIGS. 4A and 4B  are flow diagrams that describe a method of making coordination between radio access points according to an embodiment of the present disclosure; 
           [0021]      FIG. 5  is a flow diagram that describes communication between base stations (eNBs), or inter-eNB communication, according to a first embodiment of the present disclosure; 
           [0022]      FIG. 6  is a block diagram of a base station according to an embodiment of the present disclosure; 
           [0023]      FIG. 7  is a diagram illustrating an environment where a UE transmits and receives data over both of a 3GPP access network and a non-3GPP access network according to an embodiment of the present disclosure; 
           [0024]      FIG. 8  is a flow diagram that describes a method of configuring offloading control management of a device, by using device management (DM) management object (MO), according to a second embodiment of the present disclosure; 
           [0025]      FIG. 9  is a flow diagram that describes a method of determining offloading control management by exchanging network attached storage (NAS) messages, according to a third embodiment of the present disclosure; 
           [0026]      FIG. 10  is a flow diagram that describes a method using wireless local area network (WLAN) offloadabilitiy according to a fourth embodiment of the present disclosure; 
           [0027]      FIG. 11  is a flow diagram that describes a method of determining offloading control establishment by exchanging NAS messages, according to a fifth embodiment of the present disclosure; 
           [0028]      FIG. 12  is a block diagram of a user equipment (UE) according to a sixth embodiment of the present disclosure; 
           [0029]      FIG. 13  is a block diagram of a DM server according to an embodiment of the present disclosure; and 
           [0030]      FIG. 14  is a block diagram of a mobility management entity (MME) according to an embodiment of the present disclosure. 
       
    
    
       [0031]    Throughout the drawings, like reference numerals will be understood to refer to like parts, components, and structures. 
       DETAILED DESCRIPTION 
       [0032]    The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure 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 various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness. 
         [0033]    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 present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents. 
         [0034]    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. 
         [0035]    By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide. 
         [0036]      FIG. 1  is a diagram illustrating a general wireless communication system according to an embodiment of the present disclosure. 
         [0037]    Referring to  FIG. 1 , the wireless communication system may include a user equipment (UE)  100 , a radio access network (RAN)  130 , and a core network  140 . 
         [0038]    The RAN  130  may be divided into several entities one of which is an entity  120  for interacting with a UE  100  through a wireless interface  110 , and the others of which are entities connected to each other via wires in the wireless communication system. Examples of the entity  120  for interacting with the UE  100  through a wireless interface  110  are an evolved node B (eNB), a node B (NB) or a radio network subsystem (RNS) including a NB, a base station or a base station subsystem (BSS) including a base station, a wireless access point, a Home eNB, a Home NB, a home eNB gateway (GW), an X2 GW, and the like. In this description, for the sake of convenience, the term, radio access point, is called the RAN  130  or at least one of the examples of the entity  120 , listed above. 
         [0039]    Except for some exceptions, the radio access point  120  generally includes one or more cells each of which controls a specific range of coverage within which the UE  100  receives corresponding services. The cell refers to a cell of a general cellular system. The radio access point  120  refers to a device that manages and controls the cells. In this description, for the sake of convenience, the radio access point  120  may be used in the sense of ‘cell.’ In addition, when describing an object, in various embodiments of the present disclosure, for the sake of convenience, the terms ‘cell’ and ‘radio access point  120 ’ may be used together. 
         [0040]    The core network  140  may include a RAN control entity  135 . The RAN control entity  135  is in charge of general control functions, such as mobility management, authentication, security, and the like. Examples of the RAN control entity  135  are a mobility management entity (MME), a Serving general packet radio service (GPRS) support node (SGSN) where GPRS is short for packet radio service, and the like. 
         [0041]    The radio access point  120  provides services to the UE  100  through a wireless interface  110 . To this end, each radio access point  120  has a proper range of coverage for providing services. 
         [0042]      FIG. 2  is a diagram illustrating a case where radio access points have one or more overlapping coverage area according to an embodiment of the present disclosure. 
         [0043]    Referring to  FIG. 2 , two general radio access points  120   a  and  120   b  adjacent to each other have coverage areas  210   a  and  210   b  ( 210 ), respectively. In this case, there may be an overlapping coverage area  220  generated as the two coverage areas  210   a  and  210   b  are overlapped. When the UE  100  receives services in the overlapping coverage area  220 , the UE  100  may be susceptible to interference. For example, when the UE  100  receives a service from a radio access point  120   a  in the overlapping coverage area  220 , the UE  100  may be susceptible to interference by the radio access point  120   b.    
         [0044]    Although the embodiments shown in  FIG. 2  are implemented in such a way that the radio access points  120   a  and  120   b  have the coverage areas  210   a  and  210   b  similar in area, it should be understood that the present disclosure is not limited by the size of coverage area. In addition, it will be appreciated that there may be various types of overlapping coverage areas where interference occurs, e.g., a case where the coverage area  210   a  of the radio access point  120   a  is located within the coverage area  210   b  of the radio access point  120   b , a case where two or more overlapping coverage area  220  are generated as the coverage areas of two or more radio access points  120  are overlapped, and the like. 
         [0045]    In addition to occurrence of interference, the overlapping coverage area  220  may also cause frequent signaling. An example of the signaling is a handover-related signaling. 
         [0046]    In order to address these issues, the 3rd Generation Partnership Project (3GPP) has recently developed a technology for a number of radio access points  120  to make cooperative communication with each other. Examples of the cooperative communication technology are coordinated multi-point transmission and reception (CoMP), carrier aggregation, and the like. 
         [0047]      FIG. 3  is a diagram illustrating a configuration of transmission and reception of coordinated information between radio access points according to an embodiment of the present disclosure. 
         [0048]    Referring to  FIG. 3 , in order to manage a problem that may be caused by the overlapping coverage area  220 , described above referring to  FIG. 2 , one or more radio access points  120  need(s) to exchange, with each other, information related to the UE  100  to which the radio access points  120  are providing services. Since there are, in general, a number of radio access points in the vicinity of one radio access point  120 , it may be advantageous that the radio access point  120  exchanges, with as many radio access points as possible, information about the UE  100  that they are providing services.  FIG. 3  illustrates a configuration designed to be proper so that the radio access point  120  exchanges, with a relatively large number of radio access points, information about the UE  100  that they are providing services. 
         [0049]    Referring to  FIG. 3 , a communication entity  300  is connected to one or more radio access points  120  through a proper interface  310 , and may perform at least one of the following processes: 
         [0050]    receiving, from one or more radio access points  120 , information about at least one of the radio access points  120  and the UE  100  served by the at least one of the radio access points  120 , and 
         [0051]    transmitting, to one or more radio access points  120 , information about at least one of the radio access points  120  and the UE  100  served by the at least one of the radio access points  120 . 
         [0052]    The communication entity  300  may be an existing entity or a new entity. Examples of the existing entity are an MME, an SGSN, a radio network controller (RNC), an evolved serving mobile location center (E-SMLC), a radio access point (including an eNB, a Node B, and the like), operations, administration, and maintenance (OAM), and the like. 
         [0053]    The proper interface  310  may vary according to types of the communication entity  300 . For example, when the communication entity  300  is a radio access point, the interface  310  may be an X2 interface (i.e., X2-C or X2-U). When the communication entity  300  is a new type of entity, the interface  310  may be a new type of interface defined to comply with the new communication entity. 
         [0054]    In addition, when the communication entity  300  is a radio access point, the communication entity  300  may need network configurations in order to distinguish the process from those of the other radio access points. For example, when the communication entity  300  is a radio access point, the communication entity  300  may require an environment where network configurations have been well established. 
         [0055]      FIGS. 4A and 4B  are flow diagrams that describe a method of making coordination between radio access points according to an embodiment of the present disclosure.  FIGS. 4A and 4B  will use the same reference numbers for the same operations. 
         [0056]    Referring to  FIGS. 4A and 4B , without considering making coordination between radio access points, the radio access point  120  may perform allocation of wireless resources, based on a state of the UE  100  to which the radio access point  120  is providing services. On the contrary, when radio access points are coordinated with each other, the radio access point  120  may perform allocation of wireless resources, based on states of the UE  100  to which other radio access points are providing services as well as a state of the UE  100  to which the radio access point  120  is providing services, in order to improve the entire performance of a number of radio access points. 
         [0057]    The state of the UE  100  may be represented by a combination of a number of factors. Typically, the state of the UE may include at least one of the following a channel state of the UE  100 , an interference condition, an amount of uplink (UL) data that have already been transmitted, an amount of UL data in a buffer to be transmitted, an amount of downlink (DL) data that have already been received, and an amount of DL data in a buffer to be received. The channel state of the UE  100  may be obtained from the measurement result of radio service (RS). The interference condition may be obtained from the measurement result of the interference measurement (IM) resource. 
         [0058]    In order to improve the entire performance of a number of radio access points  120 , the radio access points  120  may show various patterns of coordination in a specific time and a specific frequency band. An example of coordination pattern may be a state where, for a corresponding time and frequency band, some of the BASE STATIONs do not allocate wireless resources and another part allocate wireless resources. In order to determine a coordination aspect, knowledge (e.g., information) is needed about the interference condition and the channel state of the UE  100  which are predicted for various patterns of coordination. 
         [0059]    The coordination between radio access points  120  may include the following four processes:
       properly setting RS- and IM-related wireless resources so that the UE  100  can measure various channel states and interference conditions,   transmitting, by UE the 100, information about channel state and/or interference condition by using properly set RS- and IM-related wireless resources (or, further, editing information transmitted from the UE  100  and/or transmitting the information to communication entity  300 ),   forming an interference coordination pattern based on information about interference condition and channel state and of UE, and   transmitting an interference coordination pattern to the radio access point  120  and scheduling the UE  100  based on the interference coordination pattern.       
 
         [0064]    Referring to  FIGS. 4A and 4B , the method of making coordination between radio access points is described as follows. 
         [0065]    The communication entity  300  may transmit establishment information about RS- and IM-related wireless resources for radio access points to the radio access point  120  in operation S 410 . For various situations, in order to detect the interference condition and the channel state of the UE  100 , eNBs may need to be coordinated with each other, to transmit RS, and to allocate IM resources. When the eNB  120  transmits RS and allocates IM resources without considering the conditions of the surrounding eNBs and the UE  100  receives the RS- and IM-related information and makes a measurement through corresponding resources, it is difficult to detect the interference condition and the channel state of the UE  100  in a corresponding condition (or coordination pattern). 
         [0066]    The radio access point  120  allocates wireless resources that the UE  100  will measure in operation S 420 . The allocation of wireless resources that the UE  100  will measure may be performed by one or more of the following: a radio resource control (RRC) connection reconfiguration message, RRCConnectionReconfiguration, an RRC connection re-establishment message, RRCConnectionReestablishment, and an RRC connection setup message, RRCConnectionSetup. More specifically, the allocation of wireless resources may be performed as the radio access point  120  transmits the physical configuration dedicated information element (IE) (physicalConfigDedicated IE) for the message to the UE  100 . 
         [0067]    The UE  100  properly re-configures physical channel configuration based on physicalConfigDedicated IE in operation S 430 . Thereafter, the UE  100  measures the interference condition and the channel state according to the physical channel configuration. 
         [0068]    The UE  100  may provide the measurement report to the radio access point  120 , based on the measured channel state and interference condition in operation S 440 . The measurement report may be reported to the radio access point  120  through physical uplink control channel (PUCCH) or physical uplink shared channel (PUSCH). In addition, when the radio access point  120  receives the information from the UE  100 , the radio access point  120  may transmit the received information with or without processing the received information to the communication entity  300  in operation S 445 . 
         [0069]    The information that the radio access point  120  transmits to the communication entity  300  may include at least one of the following: 
         [0070]    measurement result by the UE  100  from resources configured in CSI-RS-Config, 
         [0071]    measurement result by the UE  100  from resources configured in CSI-RS-ConfigZP, 
         [0072]    measurement result by the UE  100  from resources configured in DMRS-Config, 
         [0073]    measurement result of CRS by UE  100 , and 
         [0074]    measurement result by the UE  100  from resources configured in CSI-IM-Config. 
         [0075]    The communication entity  300  may transmit a coordination pattern to the radio access point  120  in operation S 450 . 
         [0076]    The radio access point  120  schedules the UE  100  based on the received coordination pattern in operation S 460 . 
         [0077]    Release 11 of 3GPP allows the UE to report the results measured from more resource element (RE) or more RE set or group than the UE before Release 11, so that the UE  100  can make a report for various channel states and interference conditions. It should be understood that one RE set or group may be one RE. For example, one RE set or group may include at least one RE. More specifically, the UE  100  of transmission mode (TM)  10  may report the measurement result about at least one of the following: 
         [0078]    Maximum three CSI-RS RE sets or groups, configured to use non-zero transmission power, 
         [0079]    Maximum four CSI-RS RE sets or groups, configured to use zero transmission power, and 
         [0080]    Maximum three CSI-IM RE sets or groups. 
         [0081]    On the contrary, the UE  100  less than TM  9  do not support CSI-IM RE set or group and a number of CSI-RS RE sets or groups. The UE of TM  9  may report the measurement result from one RE set or group set as csi-RS-r10. 
         [0082]    As described above, it may be important to detect information about the interference condition and channel state of the UE  100  when there are various patterns of coordination in order to make coordination between radio access points  120 . After detecting the interference condition and channel state of the UE  100 , the communication entity  300  may calculate a proper coordination pattern based on the detections. 
         [0083]    In operation S 470 , the radio access point  120  may notify the communication entity  300  of information about the allocation of wireless resources scheduled for the UE  100  in operation S 460 . 
         [0084]      FIG. 5  is a flow diagram that describes communication between base stations, inter-eNB communication, according to a first embodiment of the present disclosure. 
         [0085]    Referring to  FIG. 5 , a flow diagram that describes a method of exchanging information required for inter-eNB cooperative communication (inter-eNB CoMP) between radio access points  120  is illustrated. For the sake of convenience, the embodiment is described, based on eNB or Base Station as one of the examples of the radio access point  120 . In this description, for the sake of convenience, the terms, eNB and base station, will be used in the same sense. It should, however, be understood that the present disclosure is not limited by the term, eNB or base station, and may also be applied to a number of objects as examples of the radio access point  120  described above. 
         [0086]    In order to exchange information between base stations  500  and  510 , one base station  510  may receive channel information, and the like, from another base station  500  in operation S 530 . The base station  510  may transmit resource allocation information (CoMP hypotheses) to the base station  500 , based on collected information in operation S 550 . The following two paragraphs describe the main content of the present disclosure. 
         [0087]    The channel information may include a reference signal received power (RSRP) measurement report and/or CSI report. Benefit metric may be transmitted to the base station  510 . The current standard has defined a transmission method for the RSRP measurement report and benefit metric, but has not defined a transmission method for CSI report. Therefore, a standard is required to transmit CSI report between base stations. 
         [0088]    The base station  510  may transmit CoMP information through a message, LOAD INFORMATION, to the base station  500  as in operation S 550 . For example, the base station  510  may transmit resource allocation information, CoMP hypotheses, to the base station  500 . For a smooth CoMP process, the base station  500  complies with CoMP information generated by the base station  510 , i.e., CoMP hypotheses. However, since connection between base stations is generally established in peer-to-peer, one base station cannot make a command to the other base station. Accordingly, it is necessary for the base station  500  to provide the base station  510  feedback about how the base station  500  complies with the received resource allocation information, CoMP hypotheses. Therefore, the base station  500  needs to represent the feedback as an enhancement of enhanced-relative narrowband transmission power (RNTP). 
         [0089]    As described above, the present disclosure provides a method of providing feedback about the CoMP information received by the base station  500 . More specifically, the present disclosure provides a method of improving RNTP IE, so that the base station  500  can provide the other base station  510  with feedback by sub-frames. In addition, the present disclosure provides a method that adds, application time point information (starting system frame number (SFN)/subframe index), in order to inform the information about a corresponding time point although latency varies between a number of base stations  500  and base station  510 , so that the application time point information received by the base station  510  informs a corresponding subframe with the feedback. 
         [0090]    Referring to  FIG. 5 , a description about an inter-eNB CoMP process is described as follows. 
         [0091]    The base station  510  may transmit a message, RESOURCE STATUS REQUEST, to the base station  500  in operation S 520 . In this case, the base station  510  may request to collect information for performing inter-eNB CoMP. The base station  510  may inform the base station  500  of the type of request information and the reporting period of the request information through the message. The type of request information may be informed of by report characteristics IE. When the request information is CSI report, the reporting period of the request information may be informed of by Reporting Periodicity of CSI Report IE. Since the CSI report is short-term channel information, the reporting period may be relatively short. An available reporting period for the CSI report may be selected from at least one of the following: 5 ms, 10 ms, 20 ms, 40 ms, and 80 ms. The reporting period for the CSI report is relatively short, while the reporting period for RSRP measurement report is selected from 120 ms, 240 ms, 480 ms, and 640 ms. 
         [0092]    After receiving the reporting period for the CSI report through the RESOURCE STATUS REQUEST, the base station  500  may use the value of the reporting period to determine the minimum interval for transmitting a RESOURCE STATUS UPDATE message containing CSI report two of which are consecutively generated. When the value of the reporting period is used to determine the minimum interval, it suggests that the base station  500  may transmit, if there are conditions (e.g., overload, no need for transmission due to small variation of channel, no UE that will make a report, and the like), a CSI report at an interval greater than the value of the reporting period for the received CSI report. 
         [0093]    The base station  510  may also inform the base station  500  information about a cell that the base station  510  wants to receive, through Cell To Report IE. In addition, a non-periodic item may be added to a message for Resource Status Reporting Initiation. 
         [0094]    In order for the base station  500  to start the requested measurement, the RESOURCE STATUS REQUEST messages to be transmitted the base station  510  may be configured as the following Tables 1, 2 and 3, for example. For example, information may be collected according to the parameters described in the following Tables 1, 2, and 3. In the Tables 1, 2, and 3, eNB1 and eNB2 correspond to base station  500  and base station  510 , respectively. It should be understood that the following Tables 1, 2, and 3 are only examples to describe the present disclosure and the RESOURCE STATUS REQUEST messages may be transmitted in modes that differ from part or all of the Tables 1, 2, and 3. 
         [0000]    
       
         
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                   
                 IE type and 
                   
                   
                 Assigned 
               
               
                 IE/Group Name 
                 Presence 
                 Range 
                 reference 
                 Semantics description 
                 Criticality 
                 Criticality 
               
               
                   
               
             
             
               
                 Message Type 
                 M 
                   
                 9.2.13 
                   
                 YES 
                 reject 
               
               
                 eNB1 Measurement 
                 M 
                   
                 INTEGER (1 . . . 4095, . . . ) 
                 Allocated by eNB 1   
                 YES 
                 reject 
               
               
                 identifier (ID) 
               
               
                 eNB2 Measurement ID 
                 C-ifRegistration- 
                   
                 INTEGER (1 . . . 4095, . . . ) 
                 Allocated by eNB 2   
                 YES 
                 ignore 
               
               
                   
                 RequestStop 
               
               
                 Registration Request 
                 M 
                   
                 ENUMERATED 
                 A value set to “stop”, indicates 
                 YES 
                 reject 
               
               
                   
                   
                   
                 (start, stop, . . . ) 
                 a request to stop all cells 
               
               
                   
                   
                   
                   
                 measurements. 
               
               
                 Report Characteristics 
                 O 
                   
                 BITSTRING 
                 Each position in the bitmap 
                 YES 
                 reject 
               
               
                   
                   
                   
                 (SIZE(32)) 
                 indicates measurement 
               
               
                   
                   
                   
                   
                 object the eNB 2  is 
               
               
                   
                   
                   
                   
                 requested to report. 
               
               
                   
                   
                   
                   
                 First Bit = physical resource 
               
               
                   
                   
                   
                   
                 block (PRB) Periodic, 
               
               
                   
                   
                   
                   
                 Second Bit = TNL load Ind 
               
               
                   
                   
                   
                   
                 Periodic, 
               
               
                   
                   
                   
                   
                 Third Bit = HW Load Ind 
               
               
                   
                   
                   
                   
                 Periodic, 
               
               
                   
                   
                   
                   
                 Fourth Bit = Composite Available 
               
               
                   
                   
                   
                   
                 Capacity Periodic, this 
               
               
                   
                   
                   
                   
                 bit should be set to 1 if 
               
               
                   
                   
                   
                   
                 at least one of the First, Second 
               
               
                   
                   
                   
                   
                 or Third bits is set to 
               
               
                   
                   
                   
                   
                 1, 
               
               
                   
                   
                   
                   
                 Fifth Bit = ABS Status Periodic, 
               
               
                   
                   
                   
                   
                 Xth Bit = CSI Feedback Periodic. 
               
               
                   
                   
                   
                   
                 Other bits shall be ignored 
               
               
                   
                   
                   
                   
                 by the eNB 2 . 
               
               
                 Cell To Report 
                   
                 1 
                   
                 Cell ID list for which measurement 
                 YES 
                 ignore 
               
               
                   
                   
                   
                   
                 is needed 
               
               
                 &gt;Cell To Report Item 
                   
                 1 . . . &lt;max- 
                   
                   
                 EACH 
                 ignore 
               
               
                   
                   
                 CellineNB&gt; 
               
               
                 &gt;&gt;Cell ID 
                 M 
                   
                 ECGI 
                   
                 — 
                 — 
               
               
                   
                   
                   
                 9.2.14 
               
               
                 Reporting Periodicity 
                 O 
                   
                 ENUMERATED 
                   
                 YES 
                 ignore 
               
               
                   
                   
                   
                 (1000 ms, 2000 ms, 
               
               
                   
                   
                   
                 5000 ms, 10000 ms, . . . ) 
               
               
                 Partial Success Indicator 
                 O 
                   
                 ENUMERATED 
                 Included if partial success is 
                 YES 
                 ignore 
               
               
                   
                   
                   
                 (partial success 
                 allowed 
               
               
                   
                   
                   
                 allowed, . . . ) 
               
               
                 Reporting Periodicity for 
                 O 
                   
                 ENUMERATED 
               
               
                 CSI Feedback periodic 
                   
                   
                 (5 ms, 10 ms, 
               
               
                   
                   
                   
                 20 ms, 40 ms, 
               
               
                   
                   
                   
                 80 ms, . . . ) 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 Range bound 
                 Explanation 
               
               
                   
                   
               
             
             
               
                   
                 maxCellineNB 
                 Maximum no. cells that can be 
               
               
                   
                   
                 served by an eNB. Value is 256. 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
             
           
               
                 TABLE 3 
               
               
                   
               
               
                 Condition 
                 Explanation 
               
               
                   
               
             
             
               
                 ifRegistrationRequestStop 
                 This IE shall be present if the Registration 
               
               
                   
                 Request IE is set to the value “stop”. 
               
               
                   
               
             
          
         
       
     
         [0095]    The base station  500  may transmit a response message to the base station  510 , in response to RESOURCE STATUS REQUEST message, in operation S 525 . The response message may include RESOURCE STATUS RESPONSE message. The base station  500  may inform the base station  510  a condition as to whether the base station  500  may report information requested by the base station  510 , through the RESOURCE STATUS RESPONSE message. For the information impossible to be reported, the base station  500  may inform the base station  510  the type of the information through Measurement Failed Report Characteristics IE and the cause impossible to be reported through Cause IE. 
         [0096]    The RESOURCE STATUS RESPONSE message may be configured as the following Tables 4 and 5, for example. For example, a condition may be shown as to whether to successfully start collecting information requested by the RESOURCE STATUS REQUEST message according to the parameters described in the following Tables 4 and 5. In the Tables 1, 2, and 3, eNB1 and eNB2 correspond to base station  500  and base station  510 , respectively. It should be understood that the following Tables 4 and 5 are only examples to describe the present disclosure and the RESOURCE STATUS RESPONSE messages may be transmitted in modes that differ from part or all of the Tables 4 and 5. 
         [0000]    
       
         
               
               
               
               
               
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                   
                   
                   
                 IE type 
                   
                   
                 Assigned 
               
               
                 IE/Group Name 
                 Presence 
                 Range 
                 and reference 
                 Semantics description 
                 Criticality 
                 Criticality 
               
               
                   
               
             
             
               
                 Message Type 
                 M 
                   
                 9.2.13 
                   
                 YES 
                 reject 
               
               
                 eNB1 Measurement 
                 M 
                   
                 INTEGER 
                 Allocated by eNB 1   
                 YES 
                 reject 
               
               
                 ID 
                   
                   
                 (1 . . . 4095, . . . ) 
               
               
                 eNB2 Measurement 
                 M 
                   
                 INTEGER 
                 Allocated by eNB 2   
                 YES 
                 reject 
               
               
                 ID 
                   
                   
                 (1 . . . 4095, . . . ) 
               
               
                 Criticality Diagnosties 
                 O 
                   
                 9.2.7 
                   
                 YES 
                 ignore 
               
               
                 Measurement Initiation 
                   
                 0 . . . 1 
                   
                 List of all cells in which 
                 YES 
                 ignore 
               
               
                 Result 
                   
                   
                   
                 measurement objects were 
               
               
                   
                   
                   
                   
                 requested, included when indicating 
               
               
                   
                   
                   
                   
                 partial success 
               
               
                 &gt;Measurement 
                   
                 1 . . . &lt;maxCellineNB&gt; 
                   
                   
                 EACH 
                 ignore 
               
               
                 Initiation Result Item 
               
               
                 &gt;&gt;Cell ID 
                 M 
                   
                 ECGI 
                   
                 — 
                 — 
               
               
                   
                   
                   
                 9.2.14 
               
               
                 &gt;&gt;Measurement 
                   
                 0 . . . 1 
                   
                 Indicates that eNB 2  could not initiate 
                 — 
                 — 
               
               
                 Failure Cause List 
                   
                   
                   
                 the measurement for at least 
               
               
                   
                   
                   
                   
                 one of the requested measurement 
               
               
                   
                   
                   
                   
                 objects in the cell 
               
               
                 &gt;&gt;&gt;Measurement 
                   
                 1 . . . &lt;maxFailedMeasObjects&gt; 
                   
                   
                 EACH 
                 ignore 
               
               
                 Failure Cause Item 
               
               
                 &gt;&gt;&gt;&gt;Measurement 
                 M 
                   
                 BITSTRING 
                 Each position in the bitmap indicates 
                 — 
                 — 
               
               
                 Failed Report 
                   
                   
                 (SIZE(32)) 
                 measurement object that 
               
               
                 Characteristics 
                   
                   
                   
                 failed to be initiated in the eNB 2 . 
               
               
                   
                   
                   
                   
                 First Bit = PRB Periodic, 
               
               
                   
                   
                   
                   
                 Second Bit = TNL load Ind Periodic, 
               
               
                   
                   
                   
                   
                 Third Bit = HW Load Ind Periodic, 
               
               
                   
                   
                   
                   
                 Fourth Bit = Composite Available 
               
               
                   
                   
                   
                   
                 Capacity Periodic, 
               
               
                   
                   
                   
                   
                 Fifth Bit = ABS Status Periodic, 
               
               
                   
                   
                   
                   
                 Xth Bit = CSI Feedback Periodic. 
               
               
                   
                   
                   
                   
                 Other bits shall be ignored by the 
               
               
                   
                   
                   
                   
                 eNB 1 . 
               
               
                 &gt;&gt;&gt;&gt;Cause 
                 M 
                   
                 9.2.6 
                 Failure cause for measurement 
                 — 
                 — 
               
               
                   
                   
                   
                   
                 objects for which the measurement 
               
               
                   
                   
                   
                   
                 cannot be initiated 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
             
           
               
                 TABLE 5 
               
               
                   
               
               
                 Range bound 
                 Explanation 
               
               
                   
               
             
             
               
                 maxFailedMeasObjects 
                 Maximum number of measurement objects 
               
               
                   
                 that can fail per measurement. Value is 32. 
               
               
                 maxCellineNB 
                 Maximum no. cells that can be served by an 
               
               
                   
                 eNB. Value is 256. 
               
               
                   
               
             
          
         
       
     
         [0097]    When all information items requested by the base station  510  are impossible to be reported, the base station  500  may transmit a RESOURCE STATUS FAILURE message to the base station  510 . The RESOURCE STATUS FAILURE message may be configured as the following Tables 6 and 7, for example. In the Tables, eNB1 and eNB2 correspond to base station  500  and base station  510 , respectively. It should be understood that the following Tables 6 and 7 are only examples to describe the present disclosure and the RESOURCE STATUS FAILURE messages may be transmitted in modes that differ from part or all of the Tables 6 and 7. 
         [0000]    
       
         
               
               
               
               
               
               
               
             
           
               
                 TABLE 6 
               
               
                   
               
               
                   
                   
                   
                 IE type 
                   
                   
                 Assigned 
               
               
                 IE/Group Name 
                 Presence 
                 Range 
                 and reference 
                 Semantics description 
                 Criticality 
                 Criticality 
               
               
                   
               
             
             
               
                 Message Type 
                 M 
                   
                 9.2.13 
                   
                 YES 
                 reject 
               
               
                 eNB1 Measurement 
                 M 
                   
                 INTEGER 
                 Allocated by eNB 1   
                 YES 
                 reject 
               
               
                 ID 
                   
                   
                 (1 . . . 4095, . . . ) 
               
               
                 eNB2 Measurement 
                 M 
                   
                 INTEGER 
                 Allocated by eNB 2   
                 YES 
                 reject 
               
               
                 ID 
                   
                   
                 (1 . . . 4095, . . . ) 
               
               
                 Cause 
                 M 
                   
                 9.2.6 
                 Ignored by the receiver when 
                 YES 
                 ignore 
               
               
                   
                   
                   
                   
                 the Complete Failure Cause 
               
               
                   
                   
                   
                   
                 Information IE is included 
               
               
                 Criticality Diagnostics 
                 O 
                   
                 9.2.7 
                   
                 YES 
                 ignore 
               
               
                 Complete Failure 
                   
                 0 . . . 1 
                   
                 Complete list of failure causes 
                 YES 
                 ignore 
               
               
                 Cause Information 
                   
                   
                   
                 for all requested cells 
               
               
                 &gt;Complete Failure 
                   
                 1 . . . &lt;maxCellineNB&gt; 
                   
                   
                 EACH 
                 ignore 
               
               
                 Cause Information 
                   
                   
               
               
                 Item 
               
               
                 &gt;&gt;Cell ID 
                 M 
                   
                 ECGI 
                   
                 — 
                 — 
               
               
                   
                   
                   
                 9.2.14 
               
               
                 &gt;&gt;Measurement 
                   
                 1 
                   
                   
                 — 
                 — 
               
               
                 Failure Cause 
               
               
                 List 
               
               
                 &gt;&gt;&gt;Measurement 
                   
                 1 . . . &lt;maxFailedMeasObjects&gt; 
                   
                   
                 EACH 
                 ignore 
               
               
                 Failure Cause 
               
               
                 Item 
               
               
                 &gt;&gt;&gt;&gt;Measurement 
                 M 
                   
                 BITSTRING 
                 Each position in the bitmap indicates 
                 — 
                 — 
               
               
                 Failed Report 
                   
                   
                 (SIZE(32)) 
                 measurement object that 
               
               
                 Characteristics 
                   
                   
                   
                 failed to be initiated in the 
               
               
                   
                   
                   
                   
                 eNB 2 . First Bit = PRB Periodic, 
               
               
                   
                   
                   
                   
                 Second Bit = TNL load Ind Periodic, 
               
               
                   
                   
                   
                   
                 Third Bit = HW Load Ind Periodic, 
               
               
                   
                   
                   
                   
                 Fourth Bit = Composite Available 
               
               
                   
                   
                   
                   
                 Capacity Periodic, 
               
               
                   
                   
                   
                   
                 Fifth Bit = ABS Status Periodic, 
               
               
                   
                   
                   
                   
                 Xth Bit = CSI Feedback Periodic. 
               
               
                   
                   
                   
                   
                 Other bits shall be ignored by 
               
               
                   
                   
                   
                   
                 the eNB 1 . 
               
               
                 &gt;&gt;&gt;&gt;Cause 
                 M 
                   
                 9.2.6 
                 Failure cause for measurements 
                 — 
                 — 
               
               
                   
                   
                   
                   
                 that cannot be initiated 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
             
           
               
                 TABLE 7 
               
               
                   
               
               
                 Range bound 
                 Explanation 
               
               
                   
               
             
             
               
                 maxCellineNB 
                 Maximum no. cells that can be served by 
               
               
                   
                 an eNB. Value is 256. 
               
               
                 maxFailedMeasObjects 
                 Max number of measurement objects that can 
               
               
                   
                 fail per measurement. Value is 32. 
               
               
                   
               
             
          
         
       
     
         [0098]    The base station  500  may report information items requested by the base station  510  in operation S 530 . The reporting may be performed by transmitting a RESOURCE STATUS UPDATE message. The base station  500  may use a value (values) of reporting period received from the base station  510  as a transmission interval for the RESOURCE STATUS UPDATE message. 
         [0099]    The RESOURCE STATUS UPDATE message may contain CSI Report IE and/or RSRP Measurement Report List IE. Since the CSI report and an RSRP measurement report have respective reporting periods that differ from each other, a RESOURCE STATUS UPDATE message may contain only one of the CSI Report IE and an RSRP Measurement Report List IE. The RESOURCE STATUS UPDATE message may be configured as the following Tables 8 and 9, for example. In the Tables 8 and 9, eNB1 and eNB2 correspond to base station  500  and base station  510 , respectively. It should be understood that the following Tables 8 and 9 are only examples to describe the present disclosure and the RESOURCE STATUS UPDATE messages may be transmitted in modes that differ from part or all of the Tables 8 and 9. 
         [0000]    
       
         
               
               
               
               
               
               
               
             
           
               
                 TABLE 8 
               
               
                   
               
               
                   
                   
                   
                   
                   
                   
                 Assigned 
               
               
                 IE/Group Name 
                 Presence 
                 Range 
                 IE type and reference 
                 Semantics description 
                 Criticality 
                 Criticality 
               
               
                   
               
             
             
               
                 Message Type 
                 M 
                   
                 9.2.13 
                   
                 YES 
                 ignore 
               
               
                 eNB1 Measurement ID 
                 M 
                   
                 INTEGER (1.4095, . . . ) 
                 Allocated by eNB 1   
                 YES 
                 reject 
               
               
                 eNB2 Measurement ID 
                 M 
                   
                 INTEGER (1.4095, . . . ) 
                 Allocated by eNB 2   
                 YES 
                 reject 
               
               
                 Cell Measurement Result 
                   
                 1 
                   
                   
                 YES 
                 ignore 
               
               
                 &gt;Cell Measurement Result Item 
                   
                 1 . . . &lt;maxCellineNB&gt; 
                   
                   
                 EACH 
                 ignore 
               
               
                 &gt;&gt;Cell ID 
                 M 
                   
                 ECGI 
               
               
                   
                   
                   
                 9.2.14 
               
               
                 &gt;&gt;Hardware Load Indicator 
                 O 
                   
                 9.2.34 
               
               
                 &gt;&gt;S1 TNL Load Indicator 
                 O 
                   
                 9.2.35 
               
               
                 &gt;&gt;Radio Resource Status 
                 O 
                   
                 9.2.37 
               
               
                 &gt;&gt;Composite Available Capacity 
                 O 
                   
                 9.2.44 
                   
                 YES 
                 ignore 
               
               
                 Group 
               
               
                 &gt;&gt;ABS Status 
                 O 
                   
                 9.2.58 
                   
                 YES 
                 ignore 
               
               
                 &gt;&gt;RSRP Measurement 
                 O 
                   
                 9.2.75 
                   
                 YES 
                 ignore 
               
               
                 Report List 
               
               
                 &gt;&gt;CSI Feedback 
                 O 
                   
                 9.2.xx 
                   
                 YES 
                 ignore 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE 9 
               
               
                   
                   
               
               
                   
                 Range bound 
                 Explanation 
               
               
                   
                   
               
             
             
               
                   
                 maxCellineNB 
                 Maximum no. cells that can be served 
               
               
                   
                   
                 by an eNB. Value is 256. 
               
               
                   
                   
               
             
          
         
       
     
         [0100]    The CSI Report IE may include CSI report information about one or more UE. More particularly, the CSI Report IE may be represented as a set of CSI report information by UE devices. The CSI report information represented by the UE devices may include CSI report information by CSI processes and UE identifiers. The UE identifier may be represented in the form of cell radio network temporary identifier (C-RNTI) of 16 bits. The UE identifier may also be represented in the form of an eNB UE X2 access point (AP) ID or in any new forms that have not been defined yet. The UE identifiers may be allocated by the base station  500 . 
         [0101]    The UE identifier may be used to bind information reference signal receive power (RSRP) measurement report and CSI report about the UE that the base station  500  provides services to. As described above, the base station  500  may receive RSRP measurement report from the base station  510 , as well as CSI report. Like the CSI report, the RSRP measurement report is information received from the UE that the base station  500  provides services to. The base station  500  may transmit the CSI report and an RSRP measurement report through the RESOURCE STATUS UPDATE messages that differ from each other, respectively. The base station  510  may need to consider the information (e.g., an RSRP measurement report and a CSI report) about the UE that the base station  500  provides services to, in order to achieve resource coordination. In this case, the base station  510  may consider the UE identifier contained in RSRP Measurement Report List IE and the UE identifier contained in CSI Report IE. 
         [0102]    CSI report information by CSI processes may include CSI process configuring indexes. CSI process configuration may be various e.g., the CSI process configuration may be determined by a combination of CSI-RS configuration and CSI-IM configuration. However, it is not efficient to transmit all values related to CSI process configurations to the base station  510 . When the base station  500  provides various CSI process configurations to the UE devices, the base station  500  causes frequency signaling between the UE devices and the base station  500 , and thus the providing method is not recommended. Therefore, it is recommended that CSI process configurations corresponding to a certain number of CSI process configuration indexes have previously been stored in the base station  500  and base station  510  and then the CSI process configuration indexes are transmitted. In addition to CSI process configuration indexes by respective CSI processes, ranking index (RI), wideband channel quality indication (CQI), and subband CQI list may also be transmitted. The subband CQI list may include subband CQIs by respective subbands. 
         [0103]    The following Tables 10 and 11 show one example of the configuration of the CSI Report IE. In the Tables 10 and 11, CSI report information by respective UE devices (CSI Information UE-Specific) may include the UE identifier (e.g., C-RNTI) and CSI report information by subbands (CSI Information Subband-Specific). The CSI report by subbands (CSI Information Subband-Specific) may include CSI report information by CSI processes (CSI Information CSI Process-Specific). The number of subbands to be reported may vary according to causes, such as a reporting period of CSI report for every bandwidth, and the like. When one subframe is formed with 110 PRBs, it will be appreciated that maximum number of subbands for CSI report is 14, considering that one subband is in general formed with 8 PRBs. The CSI report information by CSI processes (CSI Information CSI Process-Specific) may include subband CQI, optionally CSI process configuration index (CSI Process Index), wideband CQI, and ranking index (RI). The CSI process configuration index, wideband CQI, and RI need not to appear for each subband and need to appear once by each CSI process. It should be understood that the following Tables 10 and 11 are only an example to describe the present disclosure and the CSI Report IE may differ from part or all of the Tables 10 and 11. 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                 TABLE 10 
               
               
                   
               
               
                 IE/Group Name 
                 Presence 
                 Range 
                 IE type and reference 
                 Semantics description 
               
               
                   
               
             
             
               
                 CSI Information(report) UE- 
                   
                 1 . . . &lt;max 
                   
                   
               
               
                 Specific 
                   
                 UECSIReport&gt; 
               
               
                 &gt;C-RNTI 
                 M 
                   
                 BIT STRING (SIZE 
                 ID of the UE served by the cell in 
               
               
                   
                   
                   
                 (16)) 
                 eNB 2.   
               
               
                   
                   
                   
                   
                 Defined in TS 36.331 [9]. 
               
               
                 &gt;CSI Information(report) 
                   
                 1 . . . &lt;maxSubband&gt; 
               
               
                 Subband-Specific 
               
               
                 &gt;&gt;CSI Information(report) 
                   
                 1 . . . &lt;maxCSIProcess&gt; 
               
               
                 CSI Process-Specific 
               
               
                 &gt;&gt;&gt;CSI Process Index 
                 O 
                   
                 INTEGER 
               
               
                   
                   
                   
                 (0 . . . 31, . . . ) 
               
               
                 &gt;&gt;&gt;Subband CQI 
                 M 
                   
                 BIT STRING 
                 Defined in TS 36.213 [11]. 
               
               
                   
                   
                   
                 (SIZE(2)) 
               
               
                 &gt;&gt;&gt;Wideband CQI 
                 O 
                   
                 BIT STRING 
                 Defined in TS 36.213 [11]. 
               
               
                   
                   
                   
                 (SIZE(4)) 
               
               
                 &gt;&gt;&gt;RI 
                 O 
                   
                 BIT STRING 
                 Defined in TS 36.213 [11]. 
               
               
                   
                   
                   
                 (SIZE(3)) 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
             
           
               
                 TABLE 11 
               
               
                   
               
               
                 Range bound 
                 Explanation 
               
               
                   
               
             
             
               
                 maxUECSIReport 
                 Maximum number of UE measurement reports. Value 
               
               
                   
                 is FFS. 
               
               
                 maxSubband 
                 Maximum number of subbands. The value is 14. 
               
               
                 maxCSIProcess 
                 Maximum number of CSI processes. The value is 4. 
               
               
                   
               
             
          
         
       
     
         [0104]    In the following description, another example of the configuration of the CSI Report IE is explained. The CSI report information represented by respective UE devices (CSI Information (report) UE-Specific) includes the UE identifier (C-RNTI) and CSI report information by CSI processes (CSI Information (report) CSI Process-Specific). The CSI report information by CSI processes (CSI Information (report) CSI Process-Specific) may include CSI report by subbands (CSI Information (report) Subband-Specific). The CSI report by subbands (CSI Information (report) Subband-Specific) may include subband CQI, optionally CSI process configuration index (CSI Process Index), wideband CQI, and RI. 
         [0105]    In addition, the base station  510  may have received benefit metric information through a message, LOAD INFORMATION, in addition to the CSI report and an RSRP measurement report. 
         [0106]    The base station  510  may generate resource allocation information, CoMP hypotheses, by using the received report information in operation S 540 . The base station  510  may transmit the generated information, CoMP hypotheses, to the base station  500  through the LOAD INFORMATION message in operation S 550 . 
         [0107]    The base station  500  makes schedule for the real serving UE considering the received resource allocation information, CoMP hypotheses, in operation S 555 . In this case, the base station  500  may not always perform resource allocation based on the received resource allocation information, CoMP hypotheses. 
         [0108]    The base station  500  may transmit, to the base station  510 , information about how resources have actually been allocated or will be allocated in operation S 560 . The information may be transmitted through a message, LOAD INFORMATION. The base station  500  may inform the base station  510  of the resource allocation determining results by sub-frames and PRBs through RNTP IE contained in the LOAD INFORMATION. The resource allocation determining results by sub-frames and PRBs may be transmitted in the form of two dimensional array. In addition, like the resource allocation information, the resource allocation determining results may be processed and transmitted in the form of one dimensional bitmap. 
         [0109]    In connecting between the base station  500  informing the resource allocation determining results and the base station  510 , transmission latency may exist. Since transmission latency may vary each time transmission is performed, the base station  510  may not surely identify a time point from which the resource allocation determining results by sub-frames and PRBs are valid. Therefore, the application time point information, starting SFN/subframe index, may also be transmitted. When the base station  510  ascertains that the application time point is not included in the resource allocation determining results, the base station  510  may consider the results to be valid immediately after receiving them. For example, the RNTP IE may be configured as the following Tables 12 and 13. It should be understood that the following Tables 12 and 13 are only examples to describe the present disclosure and the RNTP IE may differ from part or all of the Tables 12 and 13. 
         [0000]    
       
         
               
               
               
               
               
               
               
             
           
               
                 TABLE 12 
               
               
                   
               
               
                   
                   
                   
                 IE type and 
                   
                   
                 Assigned 
               
               
                 IE/Group Name 
                 Presence 
                 Range 
                 reference 
                 Semantics description 
                 Criticality 
                 Criticality 
               
               
                   
               
             
             
               
                 RNTP Per PRB 
                 M 
                   
                 BIT STRING 
                 Each position in the bitmap represents 
                 — 
                 — 
               
               
                   
                   
                   
                 (6 . . . 110, . . . ) 
                 a n PRB  value (i.e., first bit = 
               
               
                   
                   
                   
                   
                 PRB 0 and so on), for which the 
               
               
                   
                   
                   
                   
                 bit value represents RNTP (n PRB ), 
               
               
                   
                   
                   
                   
                 defined in TS 36.213 [11]. 
               
               
                   
                   
                   
                   
                 Value 0 indicates “Tx not exceeding 
               
               
                   
                   
                   
                   
                 RNTP threshold”. 
               
               
                   
                   
                   
                   
                 Value 1 indicates “no promise on 
               
               
                   
                   
                   
                   
                 the Tx power is given”. 
               
               
                   
                   
                   
                   
                 This IE is used to indicate DL 
               
               
                   
                   
                   
                   
                 power restriction per PRB in 
               
               
                   
                   
                   
                   
                 case the DL power restriction is 
               
               
                   
                   
                   
                   
                 static, i.e., the DL power 
               
               
                   
                   
                   
                   
                 restriction in a cell is maintained 
               
               
                   
                   
                   
                   
                 as the subframe number 
               
               
                   
                   
                   
                   
                 changes. 
               
               
                 RNTP Threshold 
                 M 
                   
                 ENUMERATED 
                 RNTP threshold  is defined in TS 36.213 
                 — 
                 — 
               
               
                   
                   
                   
                 (−∞, 
                 [11]. 
               
               
                   
                   
                   
                 −11, −10, −9, 
               
               
                   
                   
                   
                 −8, −7, −6, −5, 
               
               
                   
                   
                   
                 −4, −3, −2, 
               
               
                   
                   
                   
                 −1, 0, 1, 2, 
               
               
                   
                   
                   
                 3, . . . ) 
               
               
                 Number Of Cell-specific 
                 M 
                   
                 ENUMERATED 
                 P (number of antenna ports for cell- 
                 — 
                 — 
               
               
                 Antenna Ports 
                   
                   
                 (1, 2, 
                 specific reference signals) defined 
               
               
                   
                   
                   
                 4, . . . ) 
                 in TS 36.211 [10] 
               
               
                 P_B 
                 M 
                   
                 INTEGER 
                 P B  is defined in TS 36.213 [11]. 
                 — 
                 — 
               
               
                   
                   
                   
                 (0 . . . 3, . . . ) 
               
               
                 PDCCH Interference Impact 
                 M 
                   
                 INTEGER 
                 Measured by Predicted Number 
                 — 
                 — 
               
               
                   
                   
                   
                 (0 . . . 4, . . . ) 
                 Of Occupied PDCCH OFDM Symbols 
               
               
                   
                   
                   
                   
                 (see TS 36.211 [10]). 
               
               
                   
                   
                   
                   
                 Value 0 means “no prediction is 
               
               
                   
                   
                   
                   
                 available”. 
               
               
                 RNTP Per PRB Per Subframe 
                   
                 0 . . . &lt;maxSubframe&gt; 
                   
                 The first item in the list corresponds 
               
               
                   
                   
                   
                   
                 to the first subframe, the second 
               
               
                   
                   
                   
                   
                 to the second subframe, and 
               
               
                   
                   
                   
                   
                 so on. 
               
               
                   
                   
                   
                   
                 Applied repeatedly, if available. 
               
               
                   
                   
                   
                   
                 This IE is not used if the DL power 
               
               
                   
                   
                   
                   
                 restriction is static. 
               
               
                 &gt;RNTP Per PRB 
                 M 
                   
                 BIT STRING 
                 Each position in the bitmap represents 
               
               
                 Subframe-Specific 
                   
                   
                 (6 . . . 110, . . . ) 
                 a n PRB  value (i.e., first bit = 
               
               
                   
                   
                   
                   
                 PRB 0 and so on), for which the 
               
               
                   
                   
                   
                   
                 bit value represents RNTP (n PRB ), 
               
               
                   
                   
                   
                   
                 defined in TS 36.213 [11]. 
               
               
                   
                   
                   
                   
                 Value 0 indicates “Tx not exceeding 
               
               
                   
                   
                   
                   
                 RNTP threshold”. 
               
               
                   
                   
                   
                   
                 Value 1 indicates “no promise on 
               
               
                   
                   
                   
                   
                 the Tx power is given”. 
               
               
                   
                   
                   
                   
                 This IE is used to indicate DL power 
               
               
                   
                   
                   
                   
                 restriction per PRB for the 
               
               
                   
                   
                   
                   
                 corresponding subframe. 
               
               
                 Starting SFN 
                 M 
                   
                 INTEGER 
                 Number of the first system frame 
               
               
                   
                   
                   
                 (0 . . . 1023, . . . ) 
                 from which the RNTP Per PRB 
               
               
                   
                   
                   
                   
                 Per Subframe IE is valid. 
               
               
                 Starting Subframe Index 
                 M 
                   
                 INTEGER 
                 Index of the first subframe from 
               
               
                   
                   
                   
                 (0 . . . 9, . . . ) 
                 which the RNTP Per PRB Per Subframe 
               
               
                   
                   
                   
                   
                 IE is valid. 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE 13 
               
               
                   
                   
               
               
                   
                 Range bound 
                 Explanation 
               
               
                   
                   
               
             
             
               
                   
                 maxSubframe 
                 Maximum number of subframes. Value is FFS. 
               
               
                   
                   
               
             
          
         
       
     
         [0110]    The base station  510  may use the received RNTP IE in determining resource allocation information later. 
         [0111]      FIG. 6  is a block diagram of a base station according to an embodiment of the present disclosure. 
         [0112]    Referring to  FIG. 6 , the base station may include a transceiver  600 , a storage unit  610  and a controller  620 . 
         [0113]    The transceiver  600  may perform transmission/reception of information required to perform operations according to the first embodiment of the present disclosure. The transceiver  600  may transmit/receive a resource status request message to/from other base station. The resource status request message may include information for requesting CSI report. The transceiver  600  may transmit/receive a resource status response message or a resource status update message to/from other base station. The resource status response message or resource status update message may include information about CSI report. 
         [0114]    In addition, the transceiver  600  may transmit/receive a load information message including resource allocation information, CoMP hypotheses. The transceiver  600  may transmit information indicating whether to comply with the received resource allocation information by using eRNTP. 
         [0115]    The storage unit  610  may store information required for the operations of the base station. The storage unit  610  may store information that the transceiver  600  has received or transmitted. 
         [0116]    The controller  620  may control the states and operations of the components in the UE. 
         [0117]    The controller  620  may control reception of a first message for requesting CSI report from other base station, and transmission of a second message including the CSI report, based on the first message, to the other base station. 
         [0118]    The controller  620  may control reception of a third message including first information about resource allocation based on the CSI report, from the other base station, allocation of resources to UE, and transmission of a fourth message including second information indicating whether to comply with the resource allocation information received from the other base station when the first base station makes a resource allocation to the other base station. 
         [0119]    The controller  620  may control transmission of a response message including fourth information about whether the reporting of the CSI report fails to the other base station. The CSI report may include a periodic CSI report. The first message may include the third information about the reporting period of the CSI report. 
         [0120]    In addition, the controller  620  may control transmission of a first message for requesting channel state information (CSI) report to other base station, and reception of a second message including the CSI report, based on the first message, from the other base station. 
         [0121]    The controller  620  may generate first information about the resource allocation based on the received CSI report, transmission of a third message including the first information to the other base station, and reception of a fourth message including second information indicating whether to comply with the resource allocation information received from the second base station when the first base station makes a resource allocation from the other base station. 
         [0122]    The controller  620  may further control reception of a response message including fourth information about whether the reporting of the CSI report fails from the other base station. The CSI report may include a periodic CSI report. The first message may include the third information about the reporting period of the CSI report. 
         [0123]    In addition, the CSI report includes an identifier of UE, a Subband-Specific CSI report, and a CSI Process-Specific CSI report. The CSI report of CSI Process-Specific includes at least one of the following: subband CQI, wideband CQI, and RI. 
         [0124]    The second information may include subframe specific information. The subframe specific information may include a starting system frame number and/or a starting subframe index. The starting system frame number may indicate a system frame to which the second information is applied. The starting subframe index may be indicated to a subframe to which the second information is applied. 
         [0125]    The first message includes a resource status request message. The second message includes a resource status update message. The third and fourth messages include load information messages. The second information included in the fourth message is included in RNTP. 
         [0126]      FIG. 7  is a diagram illustrating an environment where a UE transmits and receives data over both of a 3GPP access network and a non-3GPP access network according to an embodiment of the present disclosure. 
         [0127]    Referring to  FIG. 7 , although the embodiment of the present disclosure describes the non-3GPP access network based on wireless local area networks (WLANs)  720  and  730 , it should be understood that the non-3GPP access network may also include other types of non-3GPP standard access network, e.g., a 1×/code division multiple access (CDMA2000)/high rate packet data (HRPD) access network, a worldwide interoperability for microwave access (WiMAX) network, and the like. 
         [0128]    The non-3GPP access network may be divided into a trusted non-3GPP access network  720  and an untrusted non-3GPP access network  730 . The division may be determined according to whether a service company trusts a non-3GPP access network connected to the service company&#39;s network. When the service company does not trust a non-3GPP access network (i.e., untrusted non-3GPP access network  730 ), the non-3GPP access network may be connected to the 3GPP service company&#39;s network, e.g., a P-GW  770 , through evolved packet data gateway (ePDG)  740 . In an embodiment of the present disclosure, the service company may include a 3GPP access network operator, and the non-3GPP access network may be a service provider contracting with a 3GPP company. 
         [0129]    On the contrary, the trusted non-3GPP access network  720  may be directly connected to the P-GW  770 , not through the ePDG  740 . As such, the trusted non-3GPP access network  720  may be directly connected to the evolved packet core (EPC). 
         [0130]    Although the embodiment of  FIG. 7  is implemented in such a way that the non-3GPP access networks  720  and  730  are, for the sake of convenience, represented as a single device, it should be understood that the non-3GPP access networks may be a network including a number of access points. More particularly, when a trusted non-3GPP access network  720  is configured with WLAN, it is called trusted WLAN access network (TWAN)  720 . In this case, the TWAN  720  may include one or more wireless fidelity (Wi-Fi) access points and trusted WLAN access gateway (TWAG). 
         [0131]    For example, the Wi-Fi access point may be connected to a 3GPP service company&#39;s network through TWAG. The TWAG may be implemented in such a way as to be physically separated from the Wi-Fi access point, or as an additional logic module on a device. 
         [0132]    Referring to  FIG. 7 , a UE  710  may also use a non-seamless WLAN offloading (NSWO) technology for directly transmitting/receiving traffic to/from an external public data network (PDN) (e.g., the Internet), not through a service company&#39;s core network, but through a trusted WLAN  720  or an untrusted WLAN  730 . 
         [0133]    In an embodiment of the present disclosure, the 3GPP mobile communication system, in particular, LTE system, may include a next generation base station  750  (e.g., an evolved universal mobile telecommunications system terrestrial radio access network (EUTRAN), an eNB, a Node B, and the like) and a serving gateway (S-GW)  760 . The UE  710  may be connected to an external network through the eNB  750 , the S-GW  760 , and the PDN Gateway (P-GW)  770 . A P-GW includes policy and charging enforcement function (PCEF). If PCEF is implemented to be separated from P-GW, the embodiment of the present disclosure may be implemented in such a way that P-GW is replaced with PCEF. 
         [0134]    A policy and charging rules function (PCRF)  780  is a device for controlling policy related to a user&#39;s quality of service (QoS). A policy and charging control (PCC) rule corresponding to a policy is transmitted to the P-GW  770 . 
         [0135]    The eNB  750  is a RAN and may perform functions corresponding to an RNC of a universal terrestrial radio access network (UTRAN) system and a base station controller (BSC) of a GSM EDGE radio access network (GERAN) system. The eNB  750  is connected to the UE  710  through a wireless channel and performs functions as existing RNC/BSC. In addition, the eNB  750  may simultaneously use a number of cells. Therefore, when the eNB  750  (e.g., the E-UTRAN) is replaced with UTRAN or GERAN, various embodiments of the present disclosure may be applied to a second generation (2G)/3G legacy network. 
         [0136]    The S-GW  760  is a device that provides data bears. The S-GW  760  may generate or remove data bearer context according to the control of MME. The functions of the S-GW  760  may correspond to those of SGSN in 2G/3G network. 
         [0137]    The unit of QoS available to wireless communication systems, such as LTE, is an evolved packet system (EPS) bearer. One EPS bearer is used to perform transmission of internet protocol (IP) Flows with the same QoS requirement. An EPS bearer has QoS-related parameters in which QoS class identifier (QCI) and allocation and retention priority (ARP) may be included. 
         [0138]    In an embodiment of the present disclosure, the EPS bearer may correspond to PDP context of GPRS system. When the UE  710  is connected to evolved packet core (EPC) through a 3GPP or non-3GPP access network, a PDN connection  790  is generated. The PDN connection  790  may include one or more EPS bearers, the IP addresses of which may be allocated according to PDN connections. In the following description, the term ‘PDN connection’ or ‘connection’ may be used in the sense of a concept including a logic path that allows the UE  710  to exchange data with PDN, through a core network, based on an IP address. 
         [0139]    When Wi-Fi and 3GPP access networks are available on the network described above, an offloading control method may be divided into a method of using information provided by base station and a method of using information provided by core network. The offloading control information provided by base station, called RAN rule or RAN assistant information, includes, when the UE selects a Wi-Fi network or traffic is transmitted through a Wi-Fi network or 3GPP access network which is selected, conditions or information to determine one of the networks in order to transmit traffic. The offloading control information provided by base station may be broadcast to all UE devices under the coverage areas of the base station through system information block (SIB) or may be transmitted to a particular UE device through RRC message. The offloading control information provided by core network is information that is determined by a network entity of a core network, e.g., a PCRF or a PCEF, and may be transmitted to the UE so as to affect the offloading operations of the UE. The offloading control information may be called an offloading rule or offloading policy. 
         [0140]    When a Wi-Fi offloading function is available to UE, there may be two paths for making a decision for Wi-Fi offloading control and transmitting the decision to the UE. When the UE simultaneously receives Wi-Fi offloading control information items from a core network and a base station, and the received Wi-Fi offloading control information items differ from each other, the UE has difficulty in performing an offloading operation based on which one of the received information items. 
         [0141]    In order to address these issues, the present disclosure provides various methods as embodiments. For example, when offloading control information items are simultaneously received from a core network and a base station, the methods according to the present disclosure prioritizes between the received offloading control information items and performs an offloading operation based on an offloading control inform item with a higher order of priority. 
         [0142]      FIG. 8  is a flow diagram that describes a method of configuring offloading control management of a device, by using device management (DM) management object (MO) according to a second embodiment of the present disclosure. 
         [0143]    Referring to  FIG. 8 , a DM server  820  configures MO and transmits the offloading control management information to a UE  800  in operation S 830 . The MO is information encoded according to the MO structure of an orthogonal multiple access (OMA) DM, and may be network attached storage (NAS) MO as a typical example. The offloading control management information of the MO may include at least one of the following: a condition as to whether the UE  800  uses offloading control information provided by base station, and information about a relative order of priority between offloading control information provided by core network and offloading control information provided by base station. 
         [0144]    The UE  800  receives MO containing offloading control management information and determines whether to use offloading control information provided by core network or a base station, based on the offloading control management information. For example, when the UE  800  receives information indicating that offloading control information provided by base station is not allowed to be used from the DM server  820 , the UE  800  receives offloading control information provided by base station from a base station  810  in operation S 840 . However the UE  800  ignores the received offloading control information in operation S 850 . When the order of priority between the offloading control information items is determined based on the offloading control management information, the UE  800  needs to apply the offloading control information with a higher order of priority to the offloading operation. 
         [0145]      FIG. 9  is a flow diagram that describes a method of determining offloading control management by exchanging NAS messages, according to a third embodiment of the present disclosure. 
         [0146]    Referring to  FIG. 9 , the embodiment is described, assuming that, when offloading control information provided by core network can be used, a UE  900  performs an offloading operation by using the offloading control information provided by core network. For example, the offloading control information provided by core network has a higher order of priority than the offloading control information provided by base station. 
         [0147]    When the UE  900  may use a core network offloading control function, the UE  900  transmits, to an MME  920 , a NAS request message (e.g., an attach request message or a tracking area update (TAU) request message) containing a condition as to whether to support an offloading control function provided by core network or a network-based offloading control function in operation S 930 . The core network offloading control function may include a network based IP flow mobility (NB-IFOM) function, i.e., network (NW)-initiated NBIFOM function. 
         [0148]    The MME  920  determines whether to allow the UE  900  to use offloading control information provided by core network, considering at least one of the subscription information, a core network, and a condition as to whether the UE  900  supports a core network offloading control function, and transmits, to the UE  900 , the NAS response message (e.g., an attach accept message or a TAU accept message) with the determined result in operation S 940 . 
         [0149]    The UE  900  receives, from a base station  910 , the offloading control information provided by the base station  910  in operation S 950 . When a determination is made to use core network offloading control information by the received NAS response message, the base station  910  ignores the information in operation S 960 . On the contrary, when a determination is made not to use the core network offloading control information, the offloading control information provided by the base station  910  is used. 
         [0150]      FIG. 10  is a flow diagram that describes a method using WLAN offloadabilitiy according to a fourth embodiment of the present disclosure. 
         [0151]    Referring to  FIG. 10 , when an offloading control function provided by core network is used for a UE  1000 , an MME  1020  may inform the UE  1000  of that an offloading control function provided by core network is used, by not configuring WLAN offloadbility indicating a condition as to whether offloading is allowed for PDN connection according to offloading control information provided by base station, or by making a configuration as ‘a configuration as ding cont and informs the UE  1000  of the configuration. 
         [0152]    The UE  1000  transmits a PDN connectivity request message to establish PDN connection to the MME  1020  in operation S 1030 . When the establishment of PDN connection is required during the process of attach, the PDN connectivity request message is included in a attach request message. In addition, the PDN connectivity request message includes information about whether the UE  1000  supports a core network offloading control function or a network-based offloading control function (NB-IFOM or NW-initiated NBIFOM). 
         [0153]    The MME  1020  determines whether to apply a core network offloading control function to the established PDN connection of the UE  1000 , considering at least one of the subscription information, a core network, and a condition as to whether the UE  1000  supports a core network offloading control function, and transmits, to the UE  1000 , the NAS response message (e.g., an activate default EPS bearer request) with the determination result in operation S 1040 . For example, the activate default EPS bearer request message that the MME  1020  transmits to the UE  1000  includes information indicating a condition as to whether a core network-based offloading control function is applied to the established PDN connection (and default EPS bearer that belonged to the connection). 
         [0154]    In addition, when a core network-based offloading control is applied to the PDN connection, WLAN offloadability, representing information about whether base station-based WLAN offloading control function is allowed, is removed or WLAN offloadability is set as setfloadability allowed, is reto explicitly inform that base station-based WLAN offloading control function is not allowed, and then the set WLAN offloadability is transmitted. 
         [0155]    The UE  1000  receives offloading control information provided by base station from a base station  1010  in operation S 1050 . When PDN connection does not exist to allow a WLAN offloading operation that has used offloading control information provided by base station according to the received information (i.e., WLAN offloadability has been set to be allowed), the UE  1000  does not use the received offloading control information provided by base station or may not receive the received offloading control information from the beginning in operation S 1060 . 
         [0156]      FIG. 11  is a flow diagram that describes a method of determining offloading control establishment by exchanging NAS messages, according to a fifth embodiment of the present disclosure. 
         [0157]    Referring to  FIG. 11 , a UE  1100  performs Attach or TAU process. During the process, the UE  1100  may transmit, to an MME  1120 , information about whether to support offloading control function provided by base station as one of Radio capability in operation S 1130 . The attach request or TAU request message that the UE  1100  transmits to the MME  1120  includes information about whether to support a network-based offloading control function or an offloading control function provided by core network. 
         [0158]    The MME  1120  determines one of the two functions as a function that the MME  1120  will use, based on information about whether to support an offloading control function provided by base station, which is received from a base station  1110  and included in UE radio capability, and information about whether to support an offloading control function provided by core network, directly received from the UE  1100  in operation S 1140 . 
         [0159]    The MME  1120  includes information about which one of the offloading control function provided by base station and the offloading control function provided by core network the MME  1120  will use in the Attach or TAU response message and transmits the message with the information to the UE  1100  in operation S 1150 . 
         [0160]    The UE  1100  may receive offloading control information provided by the base station  1110  in operation S 1160 . When a determination has been made to use an offloading control function provided by core network according to the received information, the UE  1100  does not use the received offloading control information provided by base station or may not receive the offloading control information from the beginning in S 1170 . 
         [0161]    Although the embodiments have been described in such a way that, when the UE receives offloading control information from a base station, the UE determines whether to use the information, it should be understood that the disclosure is not limited to the embodiments. There may be a case that the UE does not have to use offloading control information provided by base station. In this case, the UE may not receive offloading control information provided by base station from the beginning. For example, the UE may omit the reception process for SIB  17 . 
         [0162]      FIG. 12  is a block diagram of a UE according to a sixth embodiment of the present disclosure. 
         [0163]    Referring to  FIG. 12 , the UE may include a transceiver  1200 , a storage unit  1210  and a controller  1220 . 
         [0164]    The transceiver  1200  may perform transmission/reception of information that the UE needs to perform operations according to an embodiment of the present disclosure. More specifically, the transceiver  1200  may receive offloading control management information from a DM server, by using DM MO. The transceiver  1200  may also receive offloading control information from a base station or a core network. The transceiver  1200  may transmit a NAS request to an MME. The transceiver  1200  may transmit information about whether to support NB-IFOM, through the NAS request. The transceiver  1200  may receive a NAS response message from the MME and also information about whether NB-IFOM is applied. 
         [0165]    The transceiver  1200  may transmit, to the MME, a PDN connection request containing information about whether to support the NB-IFOM, and may receive, from the MME, a default bearer activation request containing information about whether NB-IFOM is applied, in response to the PDN connection request. The transceiver  1200  may transmit, to the MME, an attach request message or a TAU request message containing information about whether to support the NB-IFOM, and may receive, from the MME, an attach response message or a TAU response message containing information about a determined offloading control function, in response to the attach request message or the TAU request message. 
         [0166]    The storage unit  1210  may store information that the UE needs to perform operations according to an embodiment of the present disclosure. The storage unit  1210  may store information that the transceiver  1200  has received or transmitted and may provide the information to the controller  1220 . 
         [0167]    The controller  1220  may control the states and operations of the components in the UE. 
         [0168]    The controller  1220  may control the transceiver  1200  to transmit/receive information to/from a base station or MME. 
         [0169]    The controller  1220  may perform offloading operations according to offloading control information provided by core network or offloading control information provided by base station received from the base station. Although the controller  1220  has received the offloading control information provided by base station, the controller  1220  may determine to ignore the information according to information received from the DM server or MME. 
         [0170]    More specifically, when the controller  1220  receives offloading control management information from the DM server, the controller  1220  may determine whether to use offloading control information provided by base station or core network, based on the received information. When the controller  1220  receives offloading control management information from the MME, the controller  1220  may determine whether to use offloading control information provided by base station or core network, based on the received information. 
         [0171]      FIG. 13  is a block diagram of a DM server according to an embodiment of the present disclosure. 
         [0172]    Referring to  FIG. 13 , the DM server may include a transceiver  1300 , a storage unit  1310 , and a controller  1320 . 
         [0173]    The transceiver  1300  may perform transmission/reception of information that the DM server needs to perform operations according to an embodiment of the present disclosure. The transceiver  1300  may transmit offloading control management information to UE. 
         [0174]    The storage unit  1310  may store information that the DM server needs to perform operations according to an embodiment of the present disclosure. 
         [0175]    The controller  1320  may control operations of the components in the DM server. The controller  1320  may control the transmission of offloading control management information from the DM server to the UE. The offloading control management information may include at least one of the following: a condition as to whether the UE uses offloading control information provided by base station, and information about a relative order of priority between offloading control information provided by core network and offloading control information provided by base station. 
         [0176]      FIG. 14  is a block diagram of an MME according to an embodiment of the present disclosure. 
         [0177]    Referring to  FIG. 14 , the MME may include a transceiver  1400 , a storage unit  1410  and a controller  1420 . 
         [0178]    The transceiver  1400  may perform transmission/reception of information that the MME needs to perform operations according to an embodiment of the present disclosure. The transceiver  1400  may receive, from the UE, an NAS request message containing information about whether the UE supports NB-IFOM. The transceiver  1400  may also transmit, to the UE, the NAS response message containing information about whether NB-IFOM is applied. 
         [0179]    The transceiver  1400  may receive, from the UE, a PDN connection request message containing a condition as to whether the UE supports NB-IFOM. The transceiver  1400  may transmit, the UE, a default bearer activation request message containing information about whether NB-IFOM is applied or whether WLAN offloading control function is allowed. 
         [0180]    The transceiver  1400  may receive, from the UE, an attach request message or a TAU request message containing a condition as to whether the UE supports NB-IFOM. The transceiver  1400  may transmit, to the UE, an attach response message or a TAU response message containing information about a determined offloading control function. 
         [0181]    The storage unit  1410  may store information that the MME needs to perform operations according to an embodiment of the present disclosure. The storage unit  1410  may store information received through the transceiver  1400 . The storage unit  1410  may also store information that will be transmitted to the UE through the transceiver  1400 . 
         [0182]    The controller  1420  may control operations of the components in the MME. 
         [0183]    The controller  1420  may determine whether to apply NB-IFOM to the UE, considering a condition as to whether the UE supports NB-IFOM, received from the UE, and the like. The controller  1420  may also generate offloading control management information about which one of the following: offloading control information provided by base station and offloading control information provided by core network the UE, will be used. 
         [0184]    According to various embodiments of the present disclosure, since CSI is requested and received between base stations, one base station can perform allocation of resources, considering channel states of the other base station performing cooperative communication. In addition, according to various embodiments of the present disclosure, since resource allocation information is received from other base station performing cooperative communication and feedback is provided about a condition as to whether to comply with the received resource allocation information, the cooperative communication between the base stations can be much smoothly maintained. 
         [0185]    While the present disclosure has been shown and described with reference to various 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 present disclosure as defined by the appended claims and their equivalents.