Abstract:
The present invention relates to a communication technology and system converging the fifth generation (5G) communication system for supporting a data rate higher than that of the 4G system with the IoT technology. Further, the present invention is applicable to the intelligent services based on the 5G communication and IoT technologies (e.g., smart home, smart building, smart city, smart car or connected car, health care, digital education, retail, security, and safety services). In more detail, a broadcast resource congestion control method of a multi-cell/multicast coordination entity (MCE) includes receiving a message including multimedia broadcast and multicast service (MBMS) congestion information from a base station, selecting an MBMS service to be controlled based on the MBMS congestion information, and transmitting a scheduling message including first control information related to the selected MBMS service to the base station.

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 application filed on Sep. 26, 2014 in the U.S. Patent and Trademark Office and assigned Ser. No. 62/055,685, and of a U.S. Provisional application filed on Oct. 31, 2014 in the U.S. Patent and Trademark Office and assigned Ser. No. 62/073,163, the entire disclosure of each of which is hereby incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to a wireless communication system. More particularly, the present disclosure relates to a broadcast resource congestion control method and apparatus for use in a wireless communication system. 
       BACKGROUND 
       [0003]    In order to meet the increasing wireless data traffic demand since the commercialization of 4G communication systems, the development focus is on the 5th Generation (5G) or pre-5G communication system. For this reason, the 5G or pre-5G communication system is called beyond 4G network communication system or post long term evolution (LTE) system. In order to accomplish a high data rate, it is considered to implement the 5G communication system on the millimeter Wave (mmWave) band (e.g., 60 GHz band). In order to mitigate propagation loss and increase propagation distance, the 5G communication system is likely to accommodate various techniques such as beamforming, massive multiple input and multiple output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and large scale antenna. Also, for throughput enhancement of the 5G communication system, research is conducted on various techniques such as small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, device to device Communication (D2D), wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), and interference cancellation. Furthermore, the ongoing research includes the use of Hybrid Frequency Shift Keying (FSK) and quadrature amplitude modulation (QAM) modulation and sliding window superposition coding (SWSC) as advanced coding modulation (ACM) scheme, filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA). 
         [0004]    The Internet is evolving from a human-centric communication network in which information is generated and consumed by human to the internet of things (IoT) in which distributed things or components exchange and process information. The combination of the cloud server-based big data processing technology and the IoT begets Internet of Everything technology. In order to secure the sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology required for implementing the IoT, recent research is focused on the sensor network, machine to machine (M2M), and Machine Type Communication technologies. In the IoT environment, it is possible to provide an intelligent internet technology (IT) which is capable of collecting and analyzing data generated from the connected things to create new values for human life. The IoT can be applied to various fields such as a smart home, a smart building, a smart city, a smart car or a connected car, a smart grid, health care, a smart appliance, and a smart medical service, through legacy information technology (IT) technology and convergence of various industries. 
         [0005]    Thus, there are various attempts to apply the IoT to the 5G communication system. For example, the sensor network, M2M, and machine type communication (MTC) technologies are implemented by means of the 5G communication technologies such as beamforming, MIMO, and array antenna. The application of the aforementioned cloud RAN as a big data processing technology is an example of convergence between the 5G and IoT technologies. 
         [0006]    As described above, studies are conducted to develop communication techniques in various fields to meet the increasing wireless data traffic demand. The MBMS-based group communication is one of those techniques. 
         [0007]    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 
       [0008]    In the MBMS-based group communication, a plurality of users may participate in the group communication simultaneously and, this may cause congestion, resulting in degradation of service reliability. 
         [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 apparatus for controlling congestion occurring in broadcast resources for a multimedia broadcast and multicast service (MBMS)-based group communication. 
         [0010]    In accordance with an aspect of the present disclosure, a broadcast resource congestion control method of a multi-cell/multicast coordination entity (MCE) in a wireless communication system is provided. The broadcast resource congestion control method includes receiving a message including MBMS congestion information from a base station, selecting an MBMS service to be controlled based on the MBMS congestion information, transmitting a scheduling message including first control information related to the selected MBMS service to the base station. 
         [0011]    In accordance with another aspect of the present disclosure, a broadcast resource congestion control method of a base station in a wireless communication system is provided. The broadcast resource congestion control method includes transmitting a message including MBMS congestion information to a MCE, receiving a scheduling message including first control information related to an MBMS service to be controlled, the MBMS service being selected based on the MBMS congestion information, and transmitting second control information related to the first control information to a terminal. 
         [0012]    In accordance with another aspect of the present disclosure, a broadcast resource congestion control method of a terminal in a wireless communication system is provided. The broadcast resource congestion control method includes receiving second control information related to first control information from a base station and transmitting third control information related to the second control information to a server, wherein the first control information includes information on an MBMS service to be controlled, and the information on the MBMS service to be controlled is determined based on MBMS congestion information transmitted from the base station to an MCE. 
         [0013]    In accordance with another aspect of the present disclosure, an MCE for broadcast resource congestion control in a wireless communication system is provided. The MCE includes a communication unit configured to communicate with other network entities and a control unit configured to control receiving a message including MBMS congestion information from a base station, selecting an MBMS service to be controlled based on the MBMS congestion information, and transmitting a scheduling message including first control information related to the selected MBMS service to the base station. 
         [0014]    In accordance with another aspect of the present disclosure, a base station for broadcast resource congestion control in a wireless communication system is provided. The base station includes a communication unit configured to communicate with other network entities and a control unit configured to control transmitting a message including MBMS congestion information to an MCE, receiving a scheduling message including first control information related to an MBMS service to be controlled, the MBMS service being selected based on the MBMS congestion information, and transmitting second control information related to the first control information to a terminal. 
         [0015]    In accordance with another aspect of the present disclosure, a terminal is provided for broadcast resource congestion control in a wireless communication system. The terminal includes a communication unit configured to communicate with other network entities and a control unit configured to control receiving second control information related to first control information from a base station and transmitting third control information related to the second control information to a server, wherein the first control information includes information on an MBMS service to be controlled, and the information on the MBMS service to be controlled is determined based on MBMS congestion information transmitted from the base station to an MCE. 
         [0016]    The present disclosure is advantageous in terms of providing a group communication service efficiently by controlling the congestion occurring in the broadcast resources for MBMS-based group communication. 
         [0017]    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 DRAWINGS 
         [0018]    The above and other aspects, features, and advantages of certain embodiments of the present disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: 
           [0019]      FIG. 1  is a diagram illustrating a system architecture for providing a broadcast service according to an embodiment of the present disclosure; 
           [0020]      FIG. 2A  is a signal flow diagram illustrating a congestion control method according to an embodiment of the present disclosure; 
           [0021]      FIG. 2B  is a flowchart illustrating a congestion control method according to an embodiment of the present disclosure; 
           [0022]      FIG. 3  is a signal flow diagram illustrating a procedure for an evolved note B (eNB) to report resource utilization status to an multi-cell/multicast coordination entity (MCE) according to an embodiment of the present disclosure; 
           [0023]      FIG. 4  is a diagram illustrating a MAC control element (CE) for use in transmitting suspension information from an eNB to a user equipment (UE) according to an embodiment of the present disclosure; 
           [0024]      FIG. 5  is a flowchart illustrating a broadcast resource congestion control method of an MCE according to an embodiment of the present disclosure; 
           [0025]      FIG. 6  is a flowchart illustrating a broadcast resource congestion control method of an eNB according to an embodiment of the present disclosure; 
           [0026]      FIG. 7  is a flowchart illustrating a broadcast resource congestion control method of a UE according to an embodiment of the present disclosure; 
           [0027]      FIG. 8  is a block diagram illustrating a configuration of an MCE according to an embodiment of the present disclosure; 
           [0028]      FIG. 9  is a block diagram illustrating a configuration of an eNB according to an embodiment of the present disclosure; 
           [0029]      FIG. 10  is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure; 
           [0030]      FIG. 11  is a diagram illustrating a configuration of a communication unit of a UE for explaining in-device coexistence (IDC) technology according to an embodiment of the present disclosure; 
           [0031]      FIG. 12  is a signal flow diagram illustrating a procedure for a UE to provide an eNB with information for use in minimizing IDC interference according to an embodiment of the present disclosure; 
           [0032]      FIG. 13  is a diagram for explaining a concept of Dual Connectivity according to an embodiment of the present disclosure; 
           [0033]      FIG. 14  is a signal flow diagram illustrating an IDC interference control procedure of a UE operating in Dual Connectivity according to an embodiment of the present disclosure; 
           [0034]      FIG. 15  is a flowchart illustrating an IDC interference control procedure of a UE according to an embodiment of the present disclosure; 
           [0035]      FIG. 16  is a flowchart illustrating an IDC interference control procedure of a master E-UTRAN node B (MeNB) according to an embodiment of the present disclosure; 
           [0036]      FIG. 17  is a flowchart illustrating an IDC interference control procedure of a secondary E-UTRAN Node B (SeNB) according to an embodiment of the present disclosure; 
           [0037]      FIG. 18  is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure; 
           [0038]      FIG. 19  is a block diagram illustrating a configuration of an MeNB according to an embodiment of the present disclosure; and 
           [0039]      FIG. 20  is a block diagram illustrating a configuration of an (SeNB) according to an embodiment of the present disclosure. 
       
    
    
       [0040]    Throughout the drawings, like reference numerals will be understood to refer to like parts, components, and structures. 
       DETAILED DESCRIPTION 
       [0041]    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. 
         [0042]    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. 
         [0043]    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. 
         [0044]    Although the description is directed to the Advanced evolved universal terrestrial radio access E-UTRA (or long term evolution advanced (LTE-A)) supporting Carrier Aggregation, it will be understood by those skilled in the art that the present disclosure can be applied even to other communication systems having a similar technical background and channel format, with a slight modification, without departing from the spirit and scope of the present disclosure. For example, the present disclosure can be applied to a multicarrier high speed packet access (HSPA) system supporting Carrier Aggregation. 
         [0045]    A description of well-known functions and structures incorporated herein may be omitted to avoid obscuring the subject matter of the present disclosure. This aims to omit unnecessary description so as to make the subject matter of the present disclosure clear. 
         [0046]    For the same reason, some elements are exaggerated, omitted or simplified in the drawings and the elements may have sizes and/or shapes different from those shown in drawings, in practice. The same reference numbers are used throughout the drawings to refer to the same or like parts. 
         [0047]    Advantages and features of the present disclosure and methods of accomplishing the same may be understood more readily by reference to the following description of various embodiments of the present disclosure and the accompanying drawings. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the various embodiments of the present disclosure set forth herein. Rather, these various embodiments of the present disclosure are provided so that this disclosure will be thorough and complete and will fully convey the concept of the disclosure to those skilled in the art, and the present disclosure will be defined by the appended claims. 
         [0048]    It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operations or steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide operations or steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
         [0049]    Furthermore, the respective block diagrams may illustrate parts of modules, segments or codes including at least one or more executable instructions for performing specific logic function(s). Moreover, it should be noted that the functions of the blocks may be performed in different order in several modifications. For example, two successive blocks may be performed substantially at the same time, or may be performed in reverse order according to their functions. 
         [0050]    The term “module” according to embodiments of the disclosure, means, but is not limited to, a software or hardware component, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), which performs certain tasks. A module may advantageously be configured to reside on the addressable storage medium and configured to be executed on one or more processors. Thus, a module may include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functionality provided for in the components and modules may be combined into fewer components and modules or further separated into additional components and modules. In addition, the components and modules may be implemented such that they execute one or more CPUs in a device or a secure multimedia card. 
         [0051]    In order to address the problem of excessive resource requirement of the unicast-based group communication, a multimedia broadcast and multicast service (MBMS)-based group communication service may be provided. For example, the MBMS-based group communication service may be provided in a public security network. 
         [0052]    In the case that a plurality of users participates in the group communication simultaneously, however, congestion may occur even in the MBMS-based group communication service and thus there is a need of a method for controlling the congestion. 
         [0053]    A description of well-known functions and structures incorporated herein may be omitted to avoid obscuring the subject matter of the present disclosure. Further, the following terms are defined in consideration of the functionality in the present disclosure, and may vary according to the intention of a user or an operator, usage, etc. Therefore, the definition should be made on the basis of the overall content of the present specification. 
         [0054]    Although the description is directed to radio access network (RAN) and evolved packet core (EPC) as the core network (CN) of the LTE specified in the 3rd generation partnership project (3GPP) standard, the present disclosure, it is obvious to those skilled in the art that the present disclosure can be applied even to other communication systems having the similar technical background and channel format, with a slight modification, without departing from the spirit and scope of the present disclosure. 
         [0055]      FIG. 1  is a diagram illustrating a system architecture for providing a broadcast service according to an embodiment of the present disclosure. 
         [0056]    Referring to  FIG. 1 , the system for providing a broadcast service (hereinafter, referred to as MBMS service) includes a group communication service application server (GCS AS)  110 , a broadcast multicast service center (BM-SC)  120 , an MBMS Gateway (MBMS GW)  130 , a mobility management entity (MME)  140 , a multi-cell/multicast coordination entity (MCE)  150 , and one or more evolved node B (eNB)  160  (shown as a plurality of sake of description). 
         [0057]    The GCS AS  110  may transmit data to a user equipment (UE). According to an embodiment of the present disclosure, the GCS AS  110  may receive information on the MBMS service to be stopped from the UE  170  through GC1 signaling. The term ‘GC1 signaling’ may be used to indicate all application level data transmitted through the GC1 interface. 
         [0058]    The BM-SC  120  may schedule the MBMS transmissions to the UEs. The BM-SC  120  may start the MBMS bearer service in response to a command from the GCS AS  110 . 
         [0059]    The MBMS GW  130  may distribute the MBMS user plane data to an evolved universal terrestrial radio access network (E-UTRAN) using IP multicasting. The MBMS GW  130  may transmit a session control signal via the MME  140 . 
         [0060]    The MME  140  is responsible for various control functions as well as the mobility management function and capable of being connected with a plurality of eNBs  160 . 
         [0061]    The MCE  150  may be implemented in separation from or included in the eNBs  160 . The MCE  150  may control allocation and authorization of radio resources for use by all eNBs  160  in a multicast broadcast single frequency network (MBSFN) area. If the radio resources for MBMS service are not sufficient, the MCE  150  may determine not to establish any radio bearer for a new MBMS service and preempt other radio resources from other radio bearers of the ongoing MBMS service according to an allocation retention priority (ARP). According to an embodiment of the present disclosure, the MCE  150  may determine the MBMS services to be stopped, switched to the unicast mode, or preempted among the congested MBMS services and transmit the determination result to the eNB  160 . 
         [0062]    The eNB  160  corresponds to the legacy node B of the universal mobile telecommunications system (UMTS). The eNB  160  is capable of functions more complex than those of the legacy node B. In the LTE system, all services including the real time services such as voice over IP (VoIP) are provided through a shared channel, the eNB  160  collects state information such as UE buffer status, power headroom status, and channel status and schedules the UEs based thereon. Typically, the eNB  160  controls a plurality of cells. 
         [0063]      FIG. 2A  is a signal flow diagram illustrating a congestion control method according to an embodiment of the present disclosure. 
         [0064]    Referring to  FIG. 2A , the MBMS group communication may cause congestion of a radio access network (RAN). 
         [0065]    If congestion occurs in the RAN, at least one of the GCS AS and MCE has to receive the information about the MBMS congestion so as to resolve the MBMS congestion. If the congestion status information is received, the GCS AS and/or MCE may perform at least one of the following control operations for the MBMS bearer and/or service. 
         [0066]    Pre-emption; 
         [0067]    Suspension; 
         [0068]    Switch to Unicast mode. 
         [0069]    In the following, a description is made of a method for the GCS AS and/or MCE to receive the MBMS-related congestion status information (hereinafter, referred to as MBMS-related congestion information) of an eNB and control the congestion status. 
         [0070]    Various embodiments of the present disclosure are described with reference to the accompanying drawings in more detail. The same reference numbers are used throughout the drawings to refer to the same or like parts. A description of well-known functions and structures incorporated herein may be omitted to avoid obscuring the subject matter of the present disclosure. 
         [0071]    Referring to  FIG. 2A , the eNB  203  reports the MBMS resource utilization status to the MCE  205  at operation S 210 . This report may be made in response to a request from the MCE  205 . 
         [0072]    Such a status report may be made periodically. In the case of reporting the MBMS resource utilization status periodically, the report period may be determined based on a request from the MCE  205  to the eNB  203 . The MCE  205  may send the eNB  203  a resource utilization status request message including the period information. 
         [0073]    The MBMS resource utilization status report may be transmitted to the MCE  205  a periodically, e.g., when the resource utilization level is greater or less than a predetermined threshold value. 
         [0074]    The resource utilization status report may be performed per MBSFN area and/or multicast channel (MCH) and/or physical multicast channel (PMCH), or per MBSFN are and/or MBSFB subframe and/or PMCH. At this time, the resource utilization status may be transmitted in the form of percentage or degrees. 
         [0075]    It is also obvious that the resource utilization status can be reported using one-bit information. For example, the eNB  203  may transmit a 1-bit indicator indicating one of normal and overload states. 
         [0076]    The resource utilization status report procedure is depicted in  FIG. 3 . 
         [0077]      FIG. 3  is a signal flow diagram illustrating a procedure for an eNB to report resource utilization status to an MCE according to an embodiment of the present disclosure. 
         [0078]    The resource utilization status report may be implemented with one of Class 1 and Class 2 procedures. 
         [0079]    The class 1 procedure includes an operation of transmitting a resource utilization status report from the eNB  303  to the MCE  305  and an operation of transmitting a response message from the MCE  305  to the eNB  303  in reply to the report. At this time, the response message may include the information indicating that the operation associated with the message transmitted by the eNB  303  is performed successfully. 
         [0080]    Meanwhile, the class 2 procedure includes an operation of transmitting a resource utilization status report from the eNB  303  to the MCE  305  and transmitting a response from the MCE  305  to the eNB  303  but does not include any operation of transmitting a response message. In the class 2 procedure, since no response message is received from the MCE  305 , the eNB  303  may assume that the MCE  305  has received the resource utilization status report successfully when no response message is received. 
         [0081]    Referring to  FIG. 3 , the operation of reporting the resource utilization status is implemented with the class 1 procedure. If the class 2 procedure is applied, it is obvious that the procedure can be implemented with only the operation at which the eNB transmits the resource utilization status report to the MCE. 
         [0082]    In  FIG. 3 , the eNB  303  transmits an MBMS CONGESTION NOTIFICATION message to report the resource utilization status the MCE  305  at operation  5310 . At this time, the message transmitted from the eNB  303  to the MCE  305  may have a name different from that used in  FIG. 3 . For example, a message called MBMS OVERLOAD NOTIFICATION may replace the MBMS CONGESTION NOTIFICATION message for use in reporting resource utilization status to the MCE  305 . 
         [0083]    The message which the eNB  303  uses to report the resource utilization status to the MCE  305  may include the content indicating the resource utilization status per MBSFN area or PMCH. Table 1 shows a structure of the above message. 
         [0000]    
       
         
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                   
                 IE type 
               
               
                 IE/Group 
                 Pres- 
                   
                 and 
               
               
                 Name 
                 ence 
                 Range 
                 reference 
               
               
                   
               
             
             
               
                 Message 
                 M 
                   
                   
               
               
                 Type 
               
               
                 MBSFN 
                 M 
                   
                 INTEGER 
               
               
                 Area ID 
                   
                   
                 (0 . . . 255) 
               
               
                 Overload 
                   
                 1 
               
               
                 Status Per 
               
               
                 PMCH List 
               
               
                 &gt;Overload 
                   
                 1..&lt;maxnoofPMCHsperMBSFNarea&gt; 
               
               
                 Status Per 
                   
                 (= 15) 
               
               
                 PMCH Item 
               
               
                 IEs 
               
               
                 &gt;&gt;PMCH 
                 M 
                   
                 ENU- 
               
               
                 Overload 
                   
                   
                 MERATED 
               
               
                 Status 
                   
                   
                 (Normal, 
               
               
                   
                   
                   
                 Overload, 
               
               
                   
                   
                   
                 . . .) 
               
               
                 &gt;&gt;Active 
                   
                 0..1 
               
               
                 MBMS 
               
               
                 Session List 
               
               
                 &gt;&gt;&gt;Active 
                   
                 1.. &lt;maxnoofSessionsPerPMCH&gt; (= 
               
               
                 MBMS 
                   
                 29) 
               
               
                 Session 
               
               
                 Item IEs 
               
               
                 &gt;&gt;&gt;&gt;MBMS 
                 M 
                   
                 TMGI 
               
               
                 Service 
               
               
                 Identity 
               
               
                   
               
             
          
         
       
     
         [0084]    Referring to Table 1, the message for use in reporting resource utilization status may include:
       MBSFN area identity (MBSFN Area ID) Information Element to identify the MBMS area of which the resource utilization status is reported; and   PMCH Overload Status Information Element to indicate the resource utilization status per PMCH supported in the MBSFN area identified by the MBSFN area identity Information Element.       
 
         [0087]    However, the aforementioned Information Elements are just examples, but the information included in the message for a resource utilization status report is not limited thereto. If it is reported that a PMCH is in overload state, the MCE recognizes that the user data of the MBMS service carried on the corresponding PMCH are not delivered smoothly via the eNB in the scheduled period based on the report. If it is reported that a PMCH is in a normal state, the MCE recognizes that there is no overload any more on the corresponding PMCH. 
         [0088]    The message used for resource utilization status report may include the information indicating the MBMS services activated per PMCH. Since no user data is delivered via the MCE, the MCE may not know the transfer of user data of the respective MBMS services (although the MCE has played the role of assigning resources for the MBMS services per PMCH in the MBMS session initialization procedure). Thus, the information on activation/deactivation per MBMS service may be necessary. 
         [0089]    If the MBMS congestion notification message is received, the MCE  305  sends the eNB  303  an MBMS congestion notification response message in replay at operation  5320 . 
         [0090]    If an overload report is received, the MCE may select one of the activated MBMS services to suspend the selected MBMS service. The suspension determination procedure of the MCE is described with reference to  FIG. 2A . Returning to  FIG. 2A , the MCE  205  which has received the resource utilization status report transmitted by the eNB  203  may include the information on the MBMS bearer(s) to be suspended immediately in the message to be transmitted to the eNB  203 . This information may be configured in the form of a Temporary Mobile Group Identity (TMGI) list. A description thereon is made in association with the operation at operation  220 . 
         [0091]    The MCE  205  counts the UEs interested in the MBMS service per TMGI at operation  5220 . That is, the eNB  203  initiates a counting procedure. The MCE  205  may suspend the service having a small number of UEs which are receiving or interested in the corresponding service. Whether to suspend a certain MBMS service may be determined based on the activated MBMS service list and/or allocation and retention priority (ARP) of the MBMS service as well as the counting result. It is obvious that considering the counting result is not mandatory. 
         [0092]    The MCE  205  determines whether to suspend at least one MBMS service and sends the eNB  203  an MBMS SCHEDULING INFORMATION message (M2) at operation  5230 . This message carries the MCCH information. 
         [0093]    The MBMS SCHEDULING INFORMATION message may include the information indicating the MBMS bearers to be suspended as well as the MCCH information. 
         [0094]    This message also may include a time stamp. The time stamp is transmitted for use at the eNB  203  in determining the time to transmit the suspension information to a UE  201 . That is, the time stamp may indicate the time when the information indicating the suspension of the corresponding MBMS service is transmitted from the eNB  203  to the UE  201 . The time stamp may be expressed by system frame number. The suspension information transmitted by the eNB  203  may be delivered until the end of the modification period right before the time indicated by an MCCH Update Time IE. 
         [0095]    Table 2 shows a configuration of the MBMS SCHEDULING INFORMATION message. 
         [0000]    
       
         
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                   
                   
                   
                 IE type 
               
               
                 IE/Group 
                 Pres- 
                   
                 and 
               
               
                 Name 
                 ence 
                 Range 
                 reference 
               
               
                   
               
             
             
               
                 Message Type 
                 M 
                   
                   
               
               
                 MCCH Update 
                 M 
                   
                 INTEGER 
               
               
                 Time 
                   
                   
                 (0 . . . 255) 
               
               
                 MBSFN Area 
                   
                 1 
               
               
                 Configuration 
               
               
                 List 
               
               
                 &gt;MBSFN Area 
                   
                 1 to 
               
               
                 Configuration 
                   
                 &lt;maxnoofMBSFNareas&gt; (= 
               
               
                 Item IEs 
                   
                 256) 
               
               
                 &gt;&gt;MBMS 
                   
                 0..1 
               
               
                 Suspension 
               
               
                 Notification 
               
               
                 List 
               
               
                 &gt;&gt;&gt;MBMS 
                   
                 1 to 
               
               
                 Suspension 
                   
                 &lt;maxnoofPMCHsperMBSFNarea&gt; 
               
               
                 Notification 
                   
                 (= 15) 
               
               
                 Item IEs 
               
               
                 &gt;&gt;&gt;&gt;SFN 
                 M 
                   
                 INTEGER 
               
               
                   
                   
                   
                 (0 . . . 1023) 
               
               
                 &gt;&gt;&gt;&gt;MBMS 
                   
                 1 
               
               
                 Sessions To Be 
               
               
                 Suspended List 
               
               
                 per PMCH 
               
               
                 &gt;&gt;&gt;&gt;&gt;MBMS 
                   
                 1 to 
               
               
                 Sessions To Be 
                   
                 &lt;maxnoofSessionsPerPMCH&gt; 
               
               
                 Suspended List 
                   
                 (= 29) 
               
               
                 per PMCH 
               
               
                 Item 
               
               
                 &gt;&gt;&gt;&gt;&gt;&gt;MBMS 
                 M 
                   
                 TMGI 
               
               
                 Service Identity 
               
               
                   
               
             
          
         
       
     
         [0096]    Referring to  FIG. 2 , the MBMS SCHEDULING INFORMATION message may be used to transmit the time stamp (SFN IE in table 2) and the identifier of the MBMS service to be suspended (TMGI) per MBSFN area per PMCH. 
         [0097]    The eNB  203  sends the UE  201  the suspension information at operation S 240 . That is, the eNB  203  may notify the UE  201  of the MBMS services suspended and/or to be suspended. 
         [0098]    The eNB  203  may use the MCH Scheduling Information (MSI) field to transmit the suspension information. The MAC Control Element called MSI consists of n scheduling information elements of {5-bit logical channel identifier (LCID) field, 11-bit Stop multicast traffic channel (MTCH) field} occupying 2n octets as shown in  FIG. 4 . 
         [0099]      FIG. 4  is a diagram illustrating an extended MAC control element (CE) for use in transmitting suspension information from an eNB to a UE according to an embodiment of the present disclosure. 
         [0100]    Referring to  FIG. 4 , the eNB uses the MAC CE called MCH scheduling information (MSI) which is extended from 2n octets to 2n+1+y octets to indicate the MBMS services to be suspended. The eNB may also transmit a predetermined value (hereinafter, value X is interchangeably used) for MTCH (identified by LCID) carrying the MBMS service to be suspended together. 
         [0101]    The predetermined value (i.e., value X) indicates that the MBMS session initiated on the corresponding MTCH has been suspended or may be suspended. The value X may follow the LCID like the legacy Stop MTCH field. For example, the value X may be set to “000”. The eNB is capable of further extending the MAC CE to notify the UE of the time when the corresponding MBMS session is suspended. 
         [0102]    Returning to  FIG. 2A , if the session suspended notification is received, the UE notifies the GCS AS of imminent suspension of the MBMS service through GC1 application signals at operation S 250 . Here, the information transmitted through the GC1 interface may include at least one of a GCS identifier (ID), TMBI, and UE location (e.g., MBMS SAI and/or ECGI). The UE may need to determine the TMGI corresponding to the LCID of the MSI CE. The GCS AS determines the services as targets for unicast conversion, suspension, and preemption based on the GCS ID and/or TMGI. If the information on the time when the corresponding MBMS session or MBMS service is suspended is received from the eNB, the UE transmits this information (with or without being processed) through the GC1 signaling. 
         [0103]    Meanwhile, the GCS AS and/or configuration management server may preconfigure some UEs to react (to initiate GC1 signaling) in response to the information received through the extended MSI MAC CE in the user authentication procedure or group communication setup procedure. In this way, it is possible to reduce the GC1 signaling. 
         [0104]    Afterward, the GCS AS  207  determines to deliver the group call (identified by TMGI and/or GCS ID) through unicast which is currently being delivered through the MBMS bearer at operation  5260 . The GCS AS  207  performs delivery mechanism conversion on the corresponding service to a unicast bearer. 
         [0105]      FIG. 2B  is a flowchart illustrating a congestion control method according to an embodiment of the present disclosure. 
         [0106]    Referring to  FIG. 2B , the eNB  203  sends the MCE  205  a MBMS resource utilization status report at operation  5270 . The eNB  203  may use the MBMS CONGESTION NOTIFICATION message to report the resource utilization status to the MCE  205 . 
         [0107]    The MBMS CONGESTION NOTIFICATION message may include the PMCH Overload Status information indicating the resource utilization status per PMCH supported in the are identified by the MBSFN Area ID and the identity information as described above. The MBMS CONGESTION NOTIFICATION message also may include the information indicating the activated MBMS services per PMCH. In the present disclosure, the information included in the MBMS CONGESTION NOTIFICATION message is referred to as MBMS congestion information. Since the information included in the MBMS CONGESTION NOTIFICATION message and the procedure of transmitting the message are identical with those described with reference to operation S 210  of  FIG. 2A , descriptions thereof are omitted herein. 
         [0108]    If the resource utilization status report is received, the MCE  205  determines the number of UEs which are receiving or interested in the MBMS service identified by each TMGI at operation  5271 . The process of determining the UEs which are receiving or interested in the MBMS service is referred to as a UE counting process. At this time, the TMGI may be used as a MBMS service identifier. 
         [0109]    After determining the number of UEs interested in the MBMS service, the MCE  205  determines the MBMS service to control at operation  5272 . At this time, controlling an MBMS service means at least one of suspending the MBMS service, switching the MBMS service from the broadcast delivery to the unicast delivery, and preempting the MBMS service. 
         [0110]    The MCE  205  may determine to control the MBMS service having the smallest number of UEs interested therein. The MCE  205  also may determine the MBMS service to control based on the activated MBMS service list and/or ARP of MBMS service as well as the number of UEs interested in the MBMS service. 
         [0111]    After determining the MBMS service to control, the MCE  205  sends the eNB  205  a scheduling information message including the information on the MBMS service to be controlled (first congestion control information) at operation S 273 . 
         [0112]    Hereinafter, the information on the MBMS service to control is referred to as MBMS service control information. In order to distinguish among the MBMS service control information transmitted by the MCE, the eNB, and the UE, the information transmitted from the MCE to the eNB is referred to as the first congestion control information, the information from the eNB to the UE as the second congestion control information, and the information from the UE to the GCS AS the third congestion control information. 
         [0113]    The first congestion control information transmitted from the MCE to the eNB may include MCCH information. The MBMS service information may include an identifier (TMGI) of the MBMS service to control. 
         [0114]    The first congestion control information transmitted by the MCE may include transmission time information (e.g., time stamp). The transmission time information means the information indicating the time when the eNB  203  transmits the MBMS service control information (i.e., second congestion control information) to the UE  201 . 
         [0115]    If the scheduling information message is received, the eNB  203  sends the UE  201  the second congestion control information at operation S 274 . The eNB  203  generates the second congestion control information based on the first congestion control information included in the scheduling information message and transmits the second congestion control information to the UE  201 . 
         [0116]    In more detail, the eNB  203  determines the MBMS service to be controlled and the channel for delivering the MBMS service based on the TMGI contained the MCCH information included in the first congestion control information and then includes the logical channel identifier of the MTCH carrying the MBMS service to be controlled in the second congestion control information. 
         [0117]    The eNB  203  may use the MSI field to transmit the second congestion control information to the UE  201 . In more detail, the eNB may transmit a predetermined value set for the MTCH carrying the MBMS service to be control in the MAC CE of MSI. At this time, the MTCH may be identified based on the LCID included in the MAC CE. The predetermined value may indicate that the MBMS service carried on the corresponding MTCH has been suspended or is to be suspended. Accordingly, the UE  201  can determine that the MBMS service provided through the MTCH corresponding to the predetermined value has been suspended or is to be suspended based on the MAC CE of the received MAI. 
         [0118]    If the second congestion control information is received, the UE  201  sends the GCS AS  207  the MBMS service control information (i.e., third congestion control information) at operation S 275 . The UE  201  determines the MBMS service to control based on the second congestion control information and generates the third congestion control information to be transmitted to the GCS AS  207  based thereon. 
         [0119]    The third congestion control information may include at least one of the GCS identifier, MBMS service identifier, and UE location (MBMS SAI and/or ECGI). The UE  201  may transmit the third congestion control information to the GCS AS  207  through GC1 application signaling. 
         [0120]    If the third congestion control information is received, the GCS AS  207  determines the MBMS services to which unicast conversion, suspension, and preemption are applied based on the GCS ID and/or TMGI. 
         [0121]    Afterward, the GCS AS  207  performs congestion control on the selected MBMS service at operation S 276 . That is, the GCS AS  207  may perform one of unicast conversion, suspension, and preemption on the selected MBMS service. 
         [0122]    Since there is no interface for direct signaling between the MCE  205  and GCS AS  207 , it is impossible for the MCE  205  to transmit the MBMS service control information to the GCS AS  207  directly. However, when congestion occurs in the radio broadcast resource, it is necessary for the MCE  205  to determine the MBMS service to control and notify the GCS AS  207  of the corresponding MBMS service. 
         [0123]    Accordingly, the MCE  205  sends the GCS AS  207  the MBMS service control information via the eNB  203  and UE  201  such that the GCS AS  207  controls the congestion on the broadcast resource and provides the group communication services efficiently through MBMS. 
         [0124]      FIG. 5  is a flowchart illustrating a broadcast resource congestion control method of an MCE according to an embodiment of the present disclosure. 
         [0125]    Referring to  FIG. 5 , an MCE receives a resource utilization status report from an eNB at operation  5510 . The eNB may send the MCE an MBMS CONGESTION NOTIFICATION message carrying the resource utilization status report in order for the MCE to determine the resource utilization status based on the MBMS congestion information included in the MBMS CONGESTION NOTIFICATION message. A more detailed description thereof is omitted herein because it has been made above. 
         [0126]    If the resource utilization status report is received, the MCE determines the number of UEs which are receiving or interested in the MBMS service per TMGI included in the MBMS CONGESTION NOTIFICATION message at operation  5520  (i.e., UE counting procedure). 
         [0127]    After determining the number of UEs which are receiving or interested in the MBMS service corresponding to each TMGI, the MCE selects an MBMS service to be controlled based on the number of UEs which are receiving or interested in the MBMS service at operation  5530 . For example, the MCE may select the MBMS service having the least number of UEs which are receiving the MBMS service or interested therein. The MCE also may select the MBMS service to be controlled based on the number of UEs which are receiving or interested in the MBMS service and MBMS congestion control information. 
         [0128]    Here, the MBMS service to be controlled may be one of the MBMS service to be suspended, the MBMS service to be switched to the unicast delivery, and the MBMS service to be preempted. 
         [0129]    After determining the MBMS service to be controlled, the MCE sends the eNB a scheduling information message including the information on the MBMS service to be controlled (the first congestion control information herein as the MBMS service control information) at operation  5540 . The first congestion control information may include MCCH information and identifier of the MBMS service to be controlled. The first congestion control information also may include transmission time information as described above. 
         [0130]    After transmitting the scheduling information, the MCE controls the corresponding MBMS service at operation  5550 . For example, the MCE may suspend the MBMS service, switch the MBMS service to the unicast delivery, or preempt the MBMS service. The MCE also may control the MBMS service as the GCS AS does. 
         [0131]    However, if the GCS AS is configured to control the MBMS service, operation  5550  may be omitted. 
         [0132]    If the MBMS service control information (i.e., first congestion control information) is received, the eNB sends the UE the MBMS service control information (i.e., second congestion control information). At this time, the second congestion control information may be generated based on the first congestion control information. 
         [0133]    If the MBMS service control information (i.e., second congestion control information) is received, the UE may send the GCS AS the MBMS service control information (i.e., third congestion control information). 
         [0134]    In this way, the MCE transmits the MBMS service control information to the GCS AS via the eNB and the UE such that the information on the MBMS service to be controlled can be delivered to the GCS AS having no direct interface. 
         [0135]      FIG. 6  is a flowchart illustrating a broadcast resource congestion control method of an eNB according to an embodiment of the present disclosure. 
         [0136]    Referring to  FIG. 6 , the eNB sends the MCE a resource utilization status report at operation  5610 . As described above, the eNB may use the MBMS CONGESTION NOTIFICATION message to report the resource utilization status to the MCE. 
         [0137]    The eNB may report the resource utilization status in response to a request from the MCE. The eNB may report the resource utilization status periodically. The eNB may determine the report period based on the value transmitted by the MCE. 
         [0138]    The eNB may report the resource utilization status to the MCE when the resource utilization level is greater than a maximum value or less than a minimum value of a predetermined threshold range. 
         [0139]    The message carrying the resource utilization status report may include the MBMS congestion information including the MBSFN area identity information and MBSFN area overload status information. The MCE may determine the resource utilization status per MBSFN area, per MCH, and per PMCH based on the MBMS congestion information. 
         [0140]    After reporting the resource utilization status, the eNB receives a response message in response to the resource utilization status report at operation S 620 . However, operation S 620  may be omitted. 
         [0141]    In more detail, the resource utilization status report method may be implemented with the class 1 procedure with the operation of receiving a response message or the class 2 procedure without the operation of receiving the response message. 
         [0142]    Afterward, the eNB receives the scheduling information message including the information on the MBMS service as a control target selected by the MCE (MBMS service control information, particularly the first congestion control information) at operation S 630 . The first congestion control information may include the service identifier of the MBMS service to be controlled. A more detailed description thereof is omitted herein because it has been made above. 
         [0143]    After receiving the MBMS service control information through the scheduling information message, the eNB sends the UE the MBMS service control information (i.e., second congestion control information) at operation S 640 . 
         [0144]    At this time, the eNB may transmit the second congestion control information using the MSI field. In more detail, the eNB may transmit a predetermined value set for the MTCH carrying the MBMS service to be control in the MAC CE of MSI. 
         [0145]    Accordingly, the UE  201  can determine that the MBMS service provided through the MTCH corresponding to the predetermined value is the service controlled or to be controlled. 
         [0146]    Afterward, the UE determines the MBMS service to be controlled based on the second congestion control information and sends the GCS AS the third congestion control information related to the MBMS service to be controlled through GC1 signaling. A description of the UE operation is made with reference to  FIG. 7 . 
         [0147]      FIG. 7  is a flowchart illustrating a broadcast resource congestion control method of a UE according to an embodiment of the present disclosure. 
         [0148]    Referring to  FIG. 7 , the UE receives the MBMS service control information (i.e., second congestion control information) related to the MBMS service to be controlled from the eNB at operation S 710 . 
         [0149]    The second congestion control information may include a logical channel identifier of the MTCH carrying the MBMS service. 
         [0150]    In more detail, the MBMS service as a control target determined by the MCE is informed to the UE using the information included in the MAC CE of MSI. At this time, the eNB transmits a predetermined value for the MTCH carrying the MBMS service in the MAC CE of MSI to indicate the MBMS service to be controlled. Accordingly, the UE may determine the MBMS service to be controlled based on the logical channel identifier of the MTCH. 
         [0151]    After receiving the second congestion control information, the UE sends the GCS AS the MBMS service control information (i.e., third congestion control information) through GCS signaling at operation S 720 . At this time, the third congestion control information may include the GCS ID, the TMGI, and the UE location. 
         [0152]    If this information is received, the GCS AS may perform one of switching the MBMS service as a control target to the unicast delivery, suspending the MBMS service, and preempting the MBMS service. 
         [0153]      FIG. 8  is a block diagram illustrating a configuration of an MCE according to an embodiment of the present disclosure. 
         [0154]    Referring to  FIG. 8 , the MCE according to an embodiment of the present disclosure includes a communication unit  810 , a control unit  820 , and a storage unit  830 . 
         [0155]    The communication unit  810  is responsible for communication with other network entities. The communication unit  810  may communicate with an MME through an M3 interface on the control plane. The communication unit  810  also may communicate with an eNB through an M2 interface on the control plane. 
         [0156]    The control unit  820  may receive a resource utilization status report from the eNB and transmit a response message in reply. The control unit  820  also may determine a number of UEs which are receiving or interested in the MBMS service. The control unit  820  is capable of determining the MBMS service to be controlled based on the resource utilization status and the number of UEs. 
         [0157]    The control unit  820  also may send the eNB a scheduling information message including MBMS service control information (or the first congestion control information) as the information on the MBMS service to be controlled. 
         [0158]    The MBMS service control information may be transmitted from the eNB to a UE and then from the UE to a GCS AS. 
         [0159]    The storage unit  830  may store the information on a period for receiving the resource utilization status report from the eNB. The storage unit  830  also may store the received resource utilization status information and the information on the MBMS service selected as a control target. 
         [0160]      FIG. 9  is a block diagram illustrating a configuration of an eNB according to an embodiment of the present disclosure. 
         [0161]    Referring to  FIG. 9 , the eNB according to an embodiment of the present disclosure includes a communication unit  910 , a control unit  920 , and a storage unit  930 . 
         [0162]    The communication unit  910  is responsible for communication with other network entities. The communication unit  910  is capable of communicating with a UE through a radio link. The communication unit  910  also may communicate with an MCE through an M2 interface. 
         [0163]    The control unit  920  may report resource utilization status to the MCE. At this time, the control unit  920  may report the resource utilization status at a period indicated in a message received from the MCE. The control unit  920  also may receive MBMS service control information (i.e., first congestion control information) from the MCE. At this time, the information may include an MBMS service identifier and transmission time information indicating the time when the MBMS service control information is transmitted to the UE. 
         [0164]    The control unit  920  may send the MBMS service control information (i.e., second congestion control information) including an identifier of the channel carrying the MBMS service to the UE. At this time, the control unit  920  may transmit the MBMS service control information using a MAC Control Element (CE) of the MSI field. The control unit  920  also may transmit the MBMS service control information (i.e., second congestion control information) to the UE based on the transmission time information received from the MCE. 
         [0165]    The storage unit  930  may store resource utilization status report period received from the MCE. The storage unit  930  also may store the MBMS service control information received from the MCE. 
         [0166]      FIG. 10  is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure. 
         [0167]    Referring to  FIG. 10 , the UE according to an embodiment of the present disclosure includes a communication unit  1010 , a control unit  1020 , and a storage unit  1030 . 
         [0168]    The communication unit  1010  is responsible for communication with other network entities. The communication unit  1010  may communicate with an eNB through a radio link. 
         [0169]    The control unit  1020  may receive MBMS service control information (i.e., second congestion control information) from the eNB. The control unit  1020  also may transmit the MBMS service control information (i.e., third congestion control information) to a GCS AS through GCI signaling. At this time, the control unit  920  may send the MBMS service control information including a GCS identifier, MBMS service identifier, and UE location to the GCS AS. 
         [0170]    The storage unit  1030  may store UE location information. The storage unit  1030  may also store the GCS identifier. The storage unit  1030  may provide the control unit  1020  with the stored information when it transmits the MBMS service control information to the GCS AS. 
         [0171]    A description is made of a method and apparatus of controlling In-Device Coexistence (IDC) interference according to an embodiment of the present disclosure. 
         [0172]    The following embodiment of the present disclosure relates to a method and apparatus for controlling in-Device coexistence (IDC) interference in a mobile communication system operating in Dual Connectivity mode. Recently, a UE is provided with multiple communication modules for short range communication technologies as well as cellular communication technology such as LTE. The UE also may receive various electric wave signals from the outside for specific purposes such as GPS. In order to achieve this, the UE is equipped with various communication modules, which may interfere with each other. In the LTE standard, IDC technology is adopted to control such interference. 
         [0173]    Dual Connectivity is being discussed to increase the per-user throughput by allowing a UE to connect with multiple eNBs in LTE. In this technology, the UE uses a plurality of serving frequencies, resulting in an increase of the probability of IDC interference. However, the current IDC technology has a drawback in that it is designed without consideration of multiple serving frequencies. The present disclosure proposes a method for controlling the IDC interference efficiently. 
         [0174]      FIG. 11  is a diagram illustrating a configuration of a communication unit of a UE for explaining the IDC technology. 
         [0175]    Referring to  FIG. 11 , IDC is a technology for minimizing the interference between communication modules embodied in a device. Recent UEs are provided with various functions for which several communication modules may be included. In addition to an LTE communication module  1100 , a GPS module  1105  and a short range communication module  1110  such as Bluetooth and WLAN module are included. Such modules are responsible for data communication through respective antennas  1115 ,  1120 , and  1125 . 
         [0176]    Although the communication systems operate on different frequency bands, the adjacent bands may cause interference between communication modules operating thereon. This is because it is difficult to separate the signals transmitted/received on the different bands from each other ideally. Furthermore, because the antennas connected to the respective communication modules must be arranged inside the UE, in which space is limited, the antennas are placed in very close proximity. Accordingly, the relative interference strength between signals transmitted/received through the tightly arranged antennas is likely to be strong. In order to mitigate the IDC interference, it is necessary for the UE to control the transmit powers of the respective communication modules. 
         [0177]    For example, when the short range communication module  1110  such a Bluetooth module and WLAN module attempts data reception on an LTE uplink, the Tx signal of the LTE communication module  1100  may cause interference to the short range communication module  1110 . In order to mitigate this interference, it can be considered to restrict the uplink maximum transmit power of the LTE communication module  1100 . Also, it can be considered to nullify the interference power amount influencing the short range communication module  1110  by suspending the operation of the LTE communication module  1100 . In contrast, the short range communication module  1110  may interfere with the reception signal of the LTE communication module  1100  on the LTE downlink. 
         [0178]    Although the IDC technology has been developed to avoid interferences among the communication modules coexisting in a device, it can be used to mitigate interference among various communication technologies of neighboring devices as proposed in the present disclosure. 
         [0179]      FIG. 12  is a signal flow diagram illustrating a procedure for a UE to provide an eNB with information for use in minimizing IDC interference according to an embodiment of the present disclosure. 
         [0180]    Referring to  FIG. 12 , the eNB  1220  may configure the UE  1210  to report the presence/absence of the IDC interference and UE-recommended IDC avoidance scheme using an RRCConnectionReconfiguration message. The OtherConfig IE of the RRCConnectionReconfiguration message may include the IDC-Config IE as shown in Table 1, and the eNB  1220  may configure the IDC report to the UE  1210  using this IE. 
         [0181]    Discontinuous Reception (DRX) configuration information for minimizing IDC interference is illustrated in Table 3. 
         [0000]    
       
         
               
               
             
               
               
               
               
               
             
               
               
               
             
               
               
               
             
               
               
             
               
               
               
             
               
               
             
               
               
               
               
             
               
               
             
               
             
           
               
                 TABLE 3 
               
               
                   
               
             
             
               
                 IDC-Config-r11 ::= 
                 SEQUENCE { 
               
             
          
           
               
                   
                 idc-Indication-r11 
                 ENUMERATED {setup} 
                 OPTIONAL, 
                 -- Need OR 
               
             
          
           
               
                   
                 autonomousDenialParameters-r11 
                 SEQUENCE { 
               
             
          
           
               
                   
                 autonomousDenialSubframes-r11 
                 ENUMERATED {n2, n5, n10, n15, 
               
             
          
           
               
                   
                 n20, n30, spare2, spare1}, 
               
             
          
           
               
                   
                 autonomousDenialValidity-r11 
                 ENUMERATED { 
               
             
          
           
               
                   
                 sf200, sf500, sf1000, sf2000, 
               
               
                   
                 spare4, spare3, spare2, spare1} 
               
             
          
           
               
                   
                 } 
                 OPTIONAL 
                 -- Need OR 
               
             
          
           
               
                   
                 ... 
               
             
          
           
               
                 } 
               
               
                   
               
             
          
         
       
     
         [0182]    If IDC interference occurs after receiving the IDC-Config IE from the eNB, the UE sends the eNB an InDeviceCoexIndication message. This message may indicate a frequency division multiplexing (FDM) or a time division multiplexing (TDM) scheme preferred by an LTE UE to avoid interference to/from Bluetooth or wireless LAN (WLAN) communication technology. 
         [0183]    In the FDM scheme, the LTE UE reports the information on the frequency interfering to or interfered from other short range communication technologies to the eNB using a radio resource control (RRC) message (InDeviceCoexIndication). Thus, the eNB may command the LTE UE to make a handover to a frequency causing no interference. 
         [0184]    In the TDM scheme, the eNB adjusts the DRX or HARQ process pattern to distribute interferences in time while maintaining the old serving frequency. 
         [0185]    For example, the eNB  1220  provides the UE  1210  with configuration information such as cell measurement and DRX configuration information using the RRC Connection Reconfiguration message  1230 . If it is determined that the measurement target frequencies indicated from the eNB are affected by IDC interference, the UE sends the eNB the DRX configuration information for minimizing the IDC interference using the TDM-AssistanceInfo IE of the InDeviceCoexIndication message  1240 . The DRX configuration information may include a DRX cycle, an offset value for indicating the DRX start time point, and a DRX Active time. 
         [0186]    DRX configuration information specified in LTE TS36.331 for minimizing IDC interference is illustrated in Table 4. 
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
               
               
             
               
               
               
             
               
               
             
               
               
             
               
               
               
             
               
               
             
               
             
           
               
                 TABLE 4 
               
               
                   
               
             
             
               
                 TDM-AssistanceInfo-r11 ::= CHOICE { 
               
             
          
           
               
                   
                 drx-AssistanceInfo-r11 
                 SEQUENCE { 
               
             
          
           
               
                   
                 drx-CycleLength-r11 
                 ENUMERATED {sf40, sf64, sf80, sf128, sf160, 
               
             
          
           
               
                   
                 sf256, spare2, spare1}, 
               
             
          
           
               
                   
                 drx-Offset-r11 
                 INTEGER (0.. 255) OPTIONAL, 
               
               
                   
                 drx-ActiveTime-r11 
                 ENUMERATED {sf20, sf30, sf40, sf60, sf80, 
               
             
          
           
               
                   
                 sf100, spare2, spare1} 
               
             
          
           
               
                   
                 }, 
               
             
          
           
               
                   
                 idc-SubframePatternList-r11 
                 IDC-SubframePatternList-r11, 
               
             
          
           
               
                   
                 ... 
               
             
          
           
               
                 } 
               
               
                   
               
             
          
         
       
     
         [0187]    Here, sf40 denotes a unit of 40 subframes. Particularly, drx-Offset denotes a value indicating the DRX start time. 
         [0188]    The drx-Offset value be defined by Equation (1). 
         [0000]      [(SFN*10)+subframe number]modulo(drx−CycleLength)=drx−Offset  Equation (1)
 
         [0189]    As shown in Equation (1), a system frame number (SFN) is used to calculate the drx-Offset. SFN is a sequence of Radio Frame which has a value in the range from 0 to 1023. After one SFN cycle (01023), the SFN is initialized to 0. After its first transmission, the InDeviceCoexIndication message may be retransmitted when at least one of the following conditions is fulfilled. 
         [0190]    Condition 1) A set of frequencies for which a measObjectEUTRA is configured and on which an IDC problem that the UE cannot resolve occurs is different from the frequency set indicated in the last transmitted InDeviceCoexIndication message. 
         [0191]    Condition 2) At least one frequency of the previously reported frequency set is different from the frequency indicated in the last transmitted InDeviceCoexIndication message. 
         [0192]    Condition 3) The TDM assistance information is different from the assistance information included in the last transmitted InDeviceCoexIndication message. 
         [0193]      FIG. 13  is a diagram for explaining a concept of Dual Connectivity according to an embodiment of the present disclosure. 
         [0194]    Referring to  FIG. 13 , a UE  1305  may connect to a macro eNB  1310  and a small cell eNB  1320  simultaneously to transmit/receive data. The macro eNB  1310  is called a master E-UTRAN Node B (MeNB), and the small cell eNB  1320  is called a secondary E-UTRAN Node B (SeNB). 
         [0195]    There may be a plurality of small cells within the service area of the MeNB which is connected to the SeNBs through a wired backhaul network  1330 , e.g., an X2 interface. 
         [0196]    According to an embodiment of the present disclosure, the UE  1305  has a total of 5 serving cells configured by the MeNB  1310  and SeNB  1320 . A set of the serving cells configured by the MeNB  1310  is referred to as a master cell group (MCG) 1340 which has a primary cell (PCell)  1341  responsible for all functions of the legacy cell such as connection establishment, connection re-establishment, and hand over. The PCell  1341  has the uplink control channel, i.e., PUCCH. The other cells are referred to as Secondary Cells (SCells)  1343 .  FIG. 13  shows a scenario where the MeNB  1310  configures one SCell and the SeNB  1320  configures three SCells. 
         [0197]    A set of the serving cells configured by the SeNB  1320  is referred to as a secondary cell group (SCG)  1350 . According to an embodiment of the present disclosure, the SCG  1350  includes three SCells  1351 ,  1353 , and  1355 . 
         [0198]    When the UE  1305  transmits/receives data to/from the two eNBs, the MeNB  1310  may send the SeNB  1320  a command to add, modify, or release serving cells. In order to make such a command, the MeNB  1310  may configure the UE  1305  to measure the serving and neighboring cells. The UE  1305  reports the measurement result to the MeNB  1310  according to the configuration information. 
         [0199]    In order for the SeNB  1320  to transmit/receive data to/from the UE  1305  efficiently, there is a need of a serving cell playing a similar role to the PCell of the MCG and, in the present disclosure, such a cell is referred to as Primary SCell (pSCell). The pSCell is selected among the serving cells of the SCG and has the uplink control channel, i.e., the UE  1305  uses the physical uplink control channel (PUCCH) to transmit the hybrid automatic repeat request (HARQ) acknowledgement (ACK)/negative acknowledgement (NACK), channel status information (CSI), and scheduling request (SR) to the eNB. 
         [0200]    The SFN is assigned distinctly to the MCG and SCG, and the UE acquires two SFNs from the management information base (MIB) broadcast through the PCell and pSCell. In the present disclosure, the SFN applied to the MCG is referred to as MCG SFN, and the SFN applied to the SCG is referred to as SCG SFN. 
         [0201]    A description is made of changing the DRX configuration using a fixed SFN when IDC interference occurs hereinafter. 
         [0202]      FIG. 14  is a signal flow diagram illustrating an IDC interference control procedure of a UE operating in Dual Connectivity according to an embodiment of the present disclosure. 
         [0203]    Referring to  FIG. 14 , the MeNB  1403  determines whether to configure Dual Connectivity to the UE  1401  in consideration of various factors such as UE capability, UE buffer status report (BSR), and presence/absence of the neighboring SeNB at operation S 1410 . 
         [0204]    The MeNB  1403  sends an SCG addition message through the X2 interface to the SeNB  1405  that is supposed to communicate with the UE  1401  at operation S 1415 . The MeNB  1403  and SeNB  1405  exchange messages necessary for performing the Dual Connectivity through the X2 interface. The above message is used to request the SeNB  1405  for the Dual Connectivity to the UE  1401 . In the present disclosure, the MeNB  1403  includes measObjectList in the above message. 
         [0205]      FIG. 14  is directed to a situation where the MeNB  1403  adds an SeNB SCG. However, the present disclosure may be applicable to the SCG modification. Accordingly, the measObjectList information may be provided to the SeNB  1405  using another X2 message, e.g., SCG Modification message, instead of SCG Addition message. 
         [0206]    The measObjectList includes the information on the measurement frequencies which the MeNB  1403  configures the UE  1401  to measure. The measObjectList may carry the information on the measurement target frequencies configured to the UE  1401  in the form of a list. The measObjectList includes frequency indices (measObjectId) and corresponding frequency information, e.g., measObjectEUTRA IE. The measObjectEUTRA includes the information on the carrier frequencies and measurement target frequency bands. 
         [0207]    The measObjectList is used to notify the SeNB  1405  of the IDC problem occurring on a certain frequency. That is, the MeNB  1403  sends the SeNB  1405  the measObjectID to indicate the frequency on which the IDC problem has occurred. At this time, the SeNB  1405  may determine the frequency indicated by the measObjectId using the measObjectList information. 
         [0208]    The SeNB  1405  sends the MeNB  1403  an SCG Addition ACK message in response to the SCG Addition message at operation S 1420 . This message includes the SCG configuration as the SCG SCell configuration information. Using the configuration, the UE  1401  may configure an SCG SCell for communication. The configuration information includes channel configuration information, transmit power information, and bearer information. 
         [0209]    If the SCG configuration is received from the SeNB  1405 , the MeNB  1403  generates the RRCConnectionReconfiguration message including the above information. If it is necessary for the UE  1401  to report the IDC problem, the MeNB  1403  includes the IDC config IE in the RRCConnectionReconfiguration message. The MeNB  1403  sends the RRCConnectionReconfiguration message to the UE  1401  at operation S 1425 . 
         [0210]    If the RRCConnectionReconfiguration message is received, the UE  1401  configures the SCG SCell using the SCG configuration information included in this message at operation  51430 . 
         [0211]    The UE  1401  receives the MIB broadcast through the pSCell of the SeNB  1405  and decodes the MIB to acquire the SCG SFN at operation S 1435 . 
         [0212]    The UE  1401  detects IDC interference to/from the LTE signal on at least one of configured SCG serving frequencies at operation  51440 . 
         [0213]    The UE  1401  calculates a drx-Offset to change the DRX configuration to cancel the interference at operation S 1445 . 
         [0214]    As described above, the drx-Offset is used to indicate the DRX start time and is calculated using Equation (1) including the SFN value. In the present disclosure, the SFN value is replaced by the MCG SFN value. That is the UE  1401  may determine the drx-Offset value to be included in the TDM-AssistanceInfo based on the MCG SFN. 
         [0215]    In the above equation, the SFN is used as a reference value for indicating the DRX start time point. In the Dual Connectivity mode, the UE  1401  may refer to the two SFNs, i.e., MCG SFN and SCG SFN. In order to inform which of the two values is used, it may be possible to define a new indicator to be carried in the InDeviceCoexIndication message, but this increases signaling overhead. Accordingly, it is preferred to pre-configure a fixed SFN and uses the fixed SFN. 
         [0216]    It is possible to use a fixed SCG SFN instead of the MCG SFN. However, it is possible to simplify the calculation operation of the UE  1401  by using the MCG SFN instead of the SCG SFN. This is because the UE  1401  has to know the MCG SFN acquired from the PCell always although the Dual Connectivity technology is not applied. Accordingly, the UE  1401  determines the drx-Offset based on the MCG SFN. 
         [0217]    The UE  1401  sends the InDeviceCoexIndication message including the above information to the MeNB  1403  at operation S 1450 . This message includes the information on the frequency affected by IDC interference, measObjectId and DRX configuration information, and TDM-AssistanceInfo. 
         [0218]    The MeNB  1403  forwards the InDeviceCoexIndication message including the above information to the SeNB  1405  at operation S 1455 . 
         [0219]    The SeNB  1405  determines whether it is possible to resolve the IDC interference problem with the TDM scheme. That is, the SeNB  1405  determines whether the IDC interference can be mitigated by changing the DRX configuration information based on the previously received measObjectList and IDC interference-affected frequency information at operation S 1465 . The SeNB  1405  may determine the frequency indicated by the measObjectID using the previously received measObjectList information. At this time, the SeNB  1405  considers that the TDM-AssistanceInfo is generated based on the MCG SFN. The SeNB  1405  also may know the offset difference between the MCG SFN and SCG SFN in advance. This can be done through a network-based solution. 
         [0220]    If it is determined that the IDC interference can be avoided by modifying the DRX configuration information, the SeNB  1405  generates new DRX configuration information by taking both the offset differences between TDM-Assistance Info information and MCG SFN and SCG SFN into consideration at operation S 1470 . Since the DRX configuration information is applied to the SCG, it is generated based on the SCG SFN. 
         [0221]    The SeNB  1405  sends the new DRX configuration information to the MeNB  1403  at operation S 1475 . The MeNB forwards the new DRX configuration information to the UE  1401  at operation S 1480 . 
         [0222]    The UE  1401  applies the new DRX configuration on the basis of the SCG SFN at operation S 1485 . 
         [0223]      FIG. 15  is a flowchart illustrating an IDC interference control procedure of a UE according to an embodiment of the present disclosure. 
         [0224]    Referring to  FIG. 15 , a UE decodes an MIB broadcast through a PCell to acquire an MCG SFN for communication with an MeNB before applying Dual Connectivity at operation S 1500 . 
         [0225]    The UE determines whether an RRCConnectionReconfiguration message including the SCG configuration and IDC-Config IE is received from the MeNB at operation S 1505 . 
         [0226]    If the SCG configuration is received, the UE establishes a connection with the SeNB in Dual Connectivity. Since the IDC-Config IE is included, if IDC interference occurs, the UE has to report the occurrence of IDC interference to the MeNB. In order to apply the Dual Connectivity, the UE decodes the MIB broadcast through the pSCell to acquire SCG SFN at operation S 1510 . 
         [0227]    The UE starts communication with the SeNB based on the SCG configuration information and SCG SFN at operation S 1515 . 
         [0228]    The UE determines whether IDC interference occurs on at least one of the serving frequency of the SCG at operation S 1520 . 
         [0229]    If IDC interference occurs on at least one of the serving frequency of the SCG, the UE generates the TDM-AssistanceInfo based on the MCG SFN at operation S 1525 . For example, the SFN information is required to derive the drx-Offset value. In order to derive drx-Offset value, SFN information is necessary. Since the UE always knows the MCG SFN received through the PCell, it can use the MCG SFN to derive the drx-Offset value. In this way, the UE can reduce signaling overhead. 
         [0230]    The UE sends the InDeviceCoexIndication message including the configured TDM-AssistanceInfo and the measObjectId IE indicating the frequency influenced by the IDC interference to the MeNB at operation S 1530 . 
         [0231]    The UE determines whether the RRCConnectionReconfiguration message including the DRX configuration is received from the MeNB at operation S 1535 . If so, the UE applies the new DRX configuration to cancel the IDC interference at operation S 1540 . 
         [0232]    After transmitting the InDeviceCoexIndication message, if aforementioned conditions are fulfilled, e.g., the IDC interference problem occurs again or TDM scheme is changed at operation S 1545 , the UE returns to operation S 1530  to transmit the InDeviceCoexIndication message. 
         [0233]      FIG. 16  is a flowchart illustrating an IDC interference control procedure of an MeNB according to an embodiment of the present disclosure. 
         [0234]    Referring to  FIG. 16 , the MeNB determines that a UE operates in the Dual Connectivity mode based on various factors at operation S 1600 . 
         [0235]    The MeNB sends a neighboring SeNB, which is supposed to participate in the dual connectivity, an SCG Addition message at operation S 1605 . This message includes the measObjectList. This information is used to indicate the frequency influenced by the IDC interference. 
         [0236]    The MeNB receives the SCG Addition ACK message from the SeNB at operation S 1610 . This message includes the SCG configuration. This information includes the information necessary for the UE to configure an SCG. 
         [0237]    The MeNB sends the UE the RRCConnectionReconfiguration message including the SCG configuration and IDC-Config IE at operation S 1615 . The IDC-Config IE is included in the RRCConnectionReocnfiguration when the MeNB wants for the UE to report the occurrence of IDC interference. 
         [0238]    The MeNB determines whether InDeviceCoexIndication message is received from the UE at operation S 1620 . 
         [0239]    The MeNB forwards the measObjectId and TDM-AssistanceInfo carried in the InDeviceCoexIndication message to the SeNB at operation S 1625 . At this time, if it is determined that the IDC interference problem cannot be addressed based on the measObjectId and TDM-AssistanceInfo although the SeNB changes the DRX configuration information, the MeNB may not forward the above information to the SeNB. It is also possible to transmit the above information unconditionally such that the SeNB makes such a determination. 
         [0240]    The MeNB receives new DRX configuration information from the SeNB at operation S 1630 . The MeNB forwards the DRX configuration information to the UE at operation S 1635 . 
         [0241]      FIG. 17  is a flowchart illustrating an IDC interference control procedure of an SeNB according to an embodiment of the present disclosure. 
         [0242]    Referring to  FIG. 17 , the SeNB receives an SCG Addition message from an MeNB at operation  51700 . If this message includes a measObjectList, the SeNB stores the measObjectList. 
         [0243]    The SeNB sends the MeNB an SCG Addition ACK message including the SCG configuration at operation S 1705 . 
         [0244]    The SeNB determines whether the InDeviceCoexIndication information is received from the MeNB at operation S 1710 . 
         [0245]    The SeNB determines the frequency being affected by the IDC interference based on the measObjectList and measObjectId of InDeviceCoexIndication information received previously at operation S 1715 . 
         [0246]    The SeNB determines whether it is possible to address the IDC interference problem with the TDM scheme at operation S 1720 . 
         [0247]    If it is possible to address the IDC interference problem with the TDM scheme, the SeNB generates new DRX configuration information for canceling the IDC interference based on the SCG SFN at operation  51725 . In more detail, the SeNB generates new DRX configuration information based on the drx-Offset included in the TDM-AssistanceInfo and offset difference between MCG SFN and SCG SFN. 
         [0248]    The SeNB sends the MeNB the DRX configuration information at operation  51730 . 
         [0249]    If it is impossible to address the IDC interference problem, the SeNB attempts to cancel the IDC interference with the FDM scheme at operation  51735 . 
         [0250]      FIG. 18  is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure. 
         [0251]    Referring to  FIG. 18 , the UE according to an embodiment of the present disclosure includes a communication unit  1810 , a control unit  1820 , and a storage unit  1830 . 
         [0252]    The communication unit  1810  is responsible for communication with other network entities. The communication unit  1810  may communicate with an MeNB to receive an MIB broadcast through a PCell. The communication unit  1810  may receive an SCG configuration information from the MeNB for Dual Connectivity operation. 
         [0253]    If IDC interference is detected on a serving frequency of the SCG, the control unit  1820  computes drx-Offset to be included in the TDM-AssistanceInfo based on the MCG SFN acquired from the MIB broadcast through the PCell. 
         [0254]    The control unit  1820  may use the MCG SFN (which may be known already) in calculating the drx-Offset so as to reduce signaling overhead. 
         [0255]    The control unit  1820  also may configure the TDM-AssistanceInfo and send the InDeviceCoexIndication message including the measObjectId indicating the frequency affected by IDC interference to the MeNB. 
         [0256]    If an RRCConnectionReconfiguration message is received from the MeNB after transmitting the InDeviceCoexIndication message, the UE may cancel the IDC interference by applying the new DRX configuration information included in the RRCConnectionReconfiguration message. 
         [0257]    If no RRCConnectionReconfiguration message is received or if a condition for transmitting the InDeviceCoexIndication message is fulfilled, the UE may retransmit the InDeviceCoexIndication message to the MeNB. 
         [0258]    The storage unit  1830  decodes the MIB broadcast through the PCell and stores the decoded MCG SFN. If it is determined that IDC interference has occurred on at least one of SCG serving frequencies, the drx-Offset is determined based on the MCG SFN stored in the storage unit  1830 . 
         [0259]    The storage unit  1830  may also store the received SCG configuration information. The storage unit  1830  may also store measObjectID as interference perpetration frequency. 
         [0260]      FIG. 19  is a block diagram illustrating a configuration of an MeNB according to an embodiment of the present disclosure. 
         [0261]    Referring to  FIG. 19 , the MeNB according to an embodiment of the present disclosure includes a communication unit  1910 , a control unit  1920 , and a storage unit  1930 . 
         [0262]    The communication unit  1910  is responsible for communication with other network entities. In more detail, the communication unit  1910  may determine whether to allow the UE to operate in the dual connectivity mode. The communication unit  1910  may send an SCG Addition message to an SeNB and receive a response message in reply. The communication unit  1910  may also forward the SCG configuration information received from the SeNB to a UE. 
         [0263]    If an SCG Addition Ack message is received from the SeNB, the control unit  1920  may control to send the RRCConnectionReconfiguration message including the SCG configuration information extracted from the SCG Addition Ack message and IDC-Config IE to the UE. 
         [0264]    If an InDeviceCoexIndication message is received from the UE, the control unit  1920  may control to send the SeNB the measObjectID and TDM-AssistanceInfo carried in the InDeviceCoexIndication message. 
         [0265]    The control unit  1920  also may determine whether the IDC interference can be resolved with the TDM scheme based on the measObjectID and TDM-AssistenceInfo carried in the InDeviceCoexIndication message. However, the determination of whether the IDC interference can be resolved with the TDM scheme may be made by the SeNB. 
         [0266]    If new DRX configuration information is received from the SeNB, the control unit  1920  may also control to transmit the above information to the UE. 
         [0267]    The storage unit  1930  may store the measObjectList as the information on the cell measurement target frequency to be configured to the UE. The measObjectList may be provided in the form of a list of frequencies. The measurement target frequency information included in the measObjectList may also be comprised of measObjectID as an index and corresponding frequency information, e.g., measObjectEUTRA IE. 
         [0268]      FIG. 20  is a block diagram illustrating a configuration of an SeNB according to an embodiment of the present disclosure. 
         [0269]    Referring to  FIG. 20 , the SeNB according to an embodiment of the present disclosure includes a communication unit  2010 , a control unit  2020 , and a storage unit  2030 . 
         [0270]    The communication unit  2010  is responsible for communication with other network entities. In more detail, the communication unit  1910  may send information necessary for the UE to operate in the dual connectivity mode to an MeNB. The communication unit  1910  may send an SCG Addition Ack message to the MeNB in response to the SCG Addition message. If IDC interference is detected, the communication unit  2010  may send the newly configured information for canceling the interference via the MeNB to the UE. 
         [0271]    In response to the SCG Addition message received from the MeNB, the control unit  2020  may transmit an SCG Addition ACK message. At this time, the SCG Addition ACK message may include the SCG configuration message. The SCG Addition message may include the measObjectList as the UE&#39;s measurement target frequency information. 
         [0272]    After transmitting the SCG Addition Ack message, the control unit  2020  may determine whether an InDeviceCoexIndication message is received from the MeNB. If the InDeviceCoexIndication message is received, the control unit  2020  may determine the frequency affected by interference based on the measObjectID included in the InDeviceCoexIndication message. 
         [0273]    The control unit  2020  may determine whether the IDC interference can be resolved with the TDM scheme. If it is determined that the IDC interference can be resolved with the TDM scheme, the control unit  2020  may determine new DRX configuration information using the drx-Offset included in the TDM-AssistanceInfo, MCG SFN, and SCG SFN. The control unit  2020  may also control to transmit the DRX configuration information to the UE via the MeNB. 
         [0274]    If the SCG Addition message received from the MeNB includes the measObjectList, the storage unit  2030  may store the measObjectList. The measObjectList may be provided in the form of a list. The measurement target frequency information included in the measObjectList may be comprised of the measObjectId as an index and the corresponding frequency information, e.g., mesObjectEUTRA IE. 
         [0275]    The stored measObjectList can be used for determining the interference perpetration frequency. 
         [0276]    It is to be appreciated that those skilled in the art can change or modify the above described embodiments without departing from the technical concept of this disclosure. Accordingly, it should be understood that above-described embodiments are essentially for illustrative purpose only but not in any way for restriction thereto. Thus, the scope of the disclosure should be determined by the appended claims and their legal equivalents rather than the specification, and various alterations and modifications within the definition and scope of the claims are included in the claims. 
         [0277]    In the above described embodiments of the present disclosure, the operations may be selectively performed or omitted. In each embodiment of the present disclosure, the operations are not necessary to be performed in the sequential order as depicted but may be performed in a changed order. Each operation may be performed independently, and each message may be transmitted independently. 
         [0278]    Some or all of the tables exemplified in the above-description are provided to help understand the present disclosure. Accordingly, a detailed description of the table is to express part of the method and apparatus proposed in the present disclosure. That is, it is preferred to approach the content of the table of the specification semantically rather than syntactically. 
         [0279]    It will be appreciated that various embodiments of the present disclosure according to the claims and description in the specification can be realized in the form of hardware, software or a combination of hardware and software. 
         [0280]    Any such software may be stored in a non-transitory computer readable storage medium. The non-transitory computer readable storage medium stores one or more programs (software modules), the one or more programs comprising instructions, which when executed by one or more processors in an electronic device, cause the electronic device to perform a method of the present disclosure. 
         [0281]    Any such software may be stored in the form of volatile or non-volatile storage such as, for example, a storage device like a Read Only Memory (ROM), whether erasable or rewritable or not, or in the form of memory such as, for example, Random Access Memory (RAM), memory chips, device or integrated circuits or on an optically or magnetically readable medium such as, for example, a Compact Disk (CD), Digital Versatile Disc (DVD), magnetic disk or magnetic tape or the like. It will be appreciated that the storage devices and storage media are various embodiments of non-transitory machine-readable storage that are suitable for storing a program or programs comprising instructions that, when executed, implement various embodiments of the present disclosure. Accordingly, various embodiments provide a program comprising code for implementing apparatus or a method as claimed in any one of the claims of this specification and a non-transitory machine-readable storage storing such a program. 
         [0282]    While the present disclosure has been 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 made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.