Patent Publication Number: US-11647363-B2

Title: Apparatus, circuit and method for controlling service access in packet data communication system

Description:
PRIORITY 
     This application is a continuation application of prior application Ser. No. 16/824,148, filed on Mar. 19, 2020, which is a continuation application of prior application Ser. No. 14/107,431, filed on Dec. 16, 2013, which has issued as U.S. Pat. No. 10,887,730 on Jan. 5, 2021 and is based on and claims priority under 35 U.S.C. § 119(a) of a Korean patent application number 10-2013-0017544, filed on Feb. 19, 2013, in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus, circuit, and method for controlling a service access in a packet data communication system. More particularly, the present invention relates to the apparatus, circuit, and method for controlling a service access using at least one of a service type and a service priority. 
     2. Description of the Related Art 
     A mobile communication system has evolved to provide various high-speed large-capacity services to User Equipments (UEs). Examples of the mobile communication system include a High Speed Downlink Packet Access (HSDPA) mobile communication system, a High Speed Uplink Packet Access (HSUPA) mobile communication system, a Long-Term Evolution (LTE) mobile communication system, an LTE-Advanced (LTE-A) mobile communication system, a High Rate Packet Data (HRPD) mobile communication system proposed in a 3rd Generation Project Partnership 2 (3GPP2), and an Institute of Electrical and Electronics Engineers (IEEE) 802.16m mobile communication system. 
     The LTE mobile communication system has been developed to effectively support a high-speed radio packet data transmission, and maximizes a throughput of a cellular radio communication system using various Radio Access (RA) schemes. The LTE-A mobile communication system enhances the LTE mobile communication system, and has an enhanced transmission capability compared with the LTE mobile communication system. 
     The LTE mobile communication system only supports packet data calls except for voice calls which have been supported in mobile communication systems of the related art, so, in the LTE mobile communication system, various schemes for supporting the voice calls have been developed. Typical examples of the various schemes for supporting the voice calls are a Packet Service Voice Call (PS Voice Call) scheme, a Voice over IP (VoIP) scheme, a Voice over LTE (VoLTE) scheme, a Single Radio Voice Call Continuity (SRVCC) scheme, etc. Each of the PS Voice Call scheme, the VoIP scheme, and the VoLTE scheme is a scheme in which a voice call is converted into packet data, and the converted packet data is transmitted. The SRVCC scheme is a scheme in which a voice call may be converted into packet data, and the converted packet data may be transmitted in a case that a UE has performed a Radio Access Technology (RAT) Inter-RAT Handover (I-RAT Handover) operation from a 3GPP network to another network different from the 3GPP network. 
     In the LTE mobile communication system, another scheme for supporting a voice call service, such as a Circuit Service FallBack (CSFB) scheme for using a voice call service used in a mobile communication system which supports each of a Packet Service (PS) and a Circuit Service (CS) such as a Universal Mobile Telecommunication system (UMTS), has been proposed. The CSFB scheme is a scheme in which a voice network of the related art is used until networks consisting of only packet data are stably served. 
     In an LTE mobile communication system, an evolved Node B (eNB) controls access to the eNB of UEs, and more specially controls the accesses to the eNB of the UEs using an Access Barring parameter. The Access Barring parameter is transmitted through a System Information Block (SIB) Type 2 (SIB Type2) message. 
     However, an access control scheme of a UE used in an LTE mobile communication system, i.e., a scheme in which an eNB controls a service access of the UE to the eNB using the Access Barring parameter, does not consider a service type and a service priority of a service which the UE intends to receive. So, it can be difficult to provide a service with a desired service quality for the UE. Therefore, there is a need for a service access control scheme for considering the service type and the service priority of the service which the UE intends to receive. 
     The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention. 
     SUMMARY OF THE INVENTION 
     Aspects of the present invention are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to propose an apparatus, circuit, and method for controlling a service access in a packet data communication system. 
     Another aspect of the present invention is to propose an apparatus, circuit, and method for controlling a service access by considering at least one of a service type and a service priority in a packet data communication system. 
     Another aspect of the present invention is to propose an apparatus, circuit, and method for controlling a service access by considering a service characteristic in a packet data communication system. 
     In accordance with an aspect of the present invention, a method for controlling a service access by an evolved Node B (eNB) in a packet data communication system is provided. The method includes broadcasting information related to whether a service access to a specific service is possible. 
     In accordance with another aspect of the present invention, a method for controlling a service access by an eNB in a packet data communication system is provided. The method includes broadcasting information related to whether a service access to a related service is possible by considering at least one of a service characteristic, a service type, and a service priority of each of services which the eNB may provide. 
     In accordance with yet another aspect of the present invention, a method for controlling a service access by a User Equipment (UE) in a packet data communication system is provided. The method includes receiving information related to whether a service access to a specific service is possible from an eNB. 
     In accordance with still another aspect of the present invention, a method for controlling a service access by a UE in a packet data communication system is provided. The method includes receiving information related to whether a service access to a related service is possible by considering at least one of a service characteristic, a service type, and a service priority of each of services which an eNB may provide. 
     In accordance with yet still another aspect of the present invention, an eNB in a packet data communication system is provided. The eNB includes a transmitter for broadcasting information related to whether a service access to a specific service is possible. 
     In accordance with still yet another aspect of the present invention, an eNB in a packet data communication system is provided. The eNB includes a transmitter for broadcasting information related to whether a service access to a related service is possible by considering at least one of a service characteristic, a service type, and a service priority of each of services which the eNB may provide. 
     In accordance with even yet another aspect of the present invention, a UE in a packet data communication system is provided. The UE includes a receiver for receiving information related to whether a service access to a specific service is possible from an eNB. 
     In accordance with even still another aspect of the present invention, a UE in a packet data communication system is provided. The UE includes a receiver for receiving information related to whether a service access to a related service is possible by considering at least one of a service characteristic, a service type, and a service priority of each of services which an eNB may provide. 
     Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    illustrates a process for controlling a Packet Service (PS) Voice Call access in a Long Term Evolution (LTE) mobile communication system according to a first exemplary embodiment of the present invention; 
         FIG.  2    illustrates an operation process of an evolved Node B (eNB), such as the eNB illustrated in  FIG.  1   , according to an exemplary embodiment of the present invention; 
         FIG.  3    illustrates an operation process of a User Equipment (UE), such as the UE illustrated in  FIG.  1   , according to an exemplary embodiment of the present invention; 
         FIG.  4    illustrates a process for controlling a PS Voice Call access in an LTE mobile communication system according to a second exemplary embodiment of the present invention; 
         FIG.  5    illustrates an operation process of an eNB, such as the eNB illustrated in  FIG.  4   , according to an exemplary embodiment of the present invention; 
         FIG.  6    illustrates an operation process of a UE, such as the UE illustrated in  FIG.  4   , according to an exemplary embodiment of the present invention; 
         FIG.  7    illustrates a process for controlling a PS Voice Call access in an LTE mobile communication system according to a third exemplary embodiment of the present invention; 
         FIG.  8    illustrates an operation process of an eNB, such as the eNB illustrated in  FIG.  7   , according to an exemplary embodiment of the present invention; 
         FIG.  9    illustrates an operation process of a UE, such as the UE illustrated in  FIG.  7   , according to an exemplary embodiment of the present invention; 
         FIG.  10    illustrates a process for controlling a PS Voice Call access in an LTE mobile communication system according to a fourth exemplary embodiment of the present invention; 
         FIG.  11    illustrates an operation process of an eNB, such as the eNB illustrated in  FIG.  10   , according to an exemplary embodiment of the present invention; 
         FIG.  12    illustrates an operation process of a UE, such as the UE illustrated in  FIG.  10   , according to an exemplary embodiment of the present invention; 
         FIG.  13    illustrates an internal structure of a UE in an LTE communication system according to an exemplary embodiment of the present invention; and 
         FIG.  14    illustrates an internal structure of an eNB in an LTE communication system according to an exemplary embodiment of the present invention. 
     
    
    
     Throughout the drawings, like reference numerals will be understood to refer to like parts, components, and structures. 
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skilled in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness. 
     The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention is provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. 
     It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces. 
     An exemplary embodiment of the present invention provides an apparatus, circuit, and method for controlling a service access in a packet data communication system. 
     An exemplary embodiment of the present invention provides an apparatus, circuit, and method for controlling a service access by considering at least one of a service type and a service priority in a packet data communication system. 
     An exemplary embodiment of the present invention provides an apparatus, circuit, and method for controlling a service access by considering a service characteristic in a packet data communication system. 
     Exemplary embodiments of the present invention are described below with reference to a Long Term Evolution (LTE) mobile communication system. However, it will be understood by those of ordinary skill in the art that exemplary embodiments of the present invention may be applied to other packet data communication systems such as a Long Term Evolution Advanced (LTE-A) mobile communication system, a High Speed Uplink Packet Access (HSUPA) mobile communication system, and a High Rate Packet Data (HRPD) mobile communication system proposed in a 3rd Generation Project Partnership 2 (3GPP2). 
     Exemplary embodiments of the present invention are described below with reference to a Packet Service (PS) Voice Call (PS Voice Call) access. However, it will be understood by those of ordinary skill in the art that exemplary embodiments of the present invention may be applied to other service access. 
       FIG.  1    illustrates a process for controlling a PS Voice Call access in an LTE mobile communication system according to a first exemplary embodiment of the present invention. 
     Referring to  FIG.  1   , an evolved Node B (eNB)  113  generates access Barring Information (ac-BarringInfo) upon determining that there is a need for a service access barring by considering system parameters in step  115 . The ac-BarringInfo indicates information on a service access which the eNB  113  intends to bar, and includes at least one of an access Barring For Emergency (ac-BarringForEmergency) parameter indicating service access barring for an emergency service, an access Barring For Mobile Originating-Signalling (ac-BarringForMo-Signalling) parameter indicating service access barring for Mobile Originating (MO)-signalling, an access Barring For Mobile Originating-Data (ac-BarringForMo-Data) parameter indicating service access barring for an MO-data, and an access Barring For Circuit Service FallBack (CSFB)-Release 10 (ac-BarringForCSFB-r10) parameter indicating service access barring for a CSFB-Release 10. 
     The ac-BarringInfo is processed in a Radio Resource Control (RRC) layer. In  FIG.  1   , it will be assumed that the ac-BarringInfo includes all of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter. 
     Each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter may indicate related service access barring if each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter is included in the ac-BarringInfo. On the other hand, each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter may indicate the related service access barring according to a parameter value of each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter. 
     The detailed description of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter will follow. 
     In an LTE mobile communication system, the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter may be included in the ac-BarringInfo, and the ac-BarringInfo may be transmitted through a System Information Block (SIB) Type 2 (SIB Type2) message. The ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, and the ac-BarringForMo-Data parameter have been added in a standard prior to an LTE-A Release 10 standard, and the ac-BarringForCSFB-r10 parameter has been added in the LTE-A Release 10 standard. 
     The ac-BarringForEmergency parameter should always be included in the ac-BarringInfo, and indicates whether a related eNB bars a service access to an emergency call using two values, e.g., “TRUE” and “FALSE”. If the value of the ac-BarringForEmergency parameter is set to “TRUE”, the ac-BarringForEmergency parameter indicates the related eNB bars the service access to the emergency call. If the value of the ac-BarringForEmergency parameter is set to “FALSE”, the ac-BarringForEmergency parameter indicates the related eNB does not bar the service access to the emergency call. 
     Each of the ac-BarringForMO-Signalling parameter, the ac-BarringForMO-Data parameter, and the ac-BarringForCSFB-r10 parameter includes the following parameters. 
     (1) ac-BarringFactor Parameter 
     The ac-BarringFactor parameter denotes an access barring ration for a related service. The ac-BarringFactor parameter may have one value representing a barring percentage from among 0 to 95. If a value of the ac-BarringFactor parameter is 0, the ac-BarringFactor parameter indicates that a service access to a related service is always allowed, i.e., 0% of the related service is barred. If the value of the ac-BarringFactor parameter is 95, the ac-BarringFactor parameter indicates that the service access to the related service is barred to 95%. 
     (2) ac-BarringTime Parameter 
     The ac-BarringTime parameter denotes access barring time for a related service. For example, the ac-BarringTime parameter may indicate one value from among 4 to 512 seconds if a service access to the related service is barred. In this case, a User Equipment (UE) does not perform a service access to a related cell, i.e., a related service corresponding to a value of the ac-BarringTime parameter. 
     (3) ac-BarringForSpecialAC Parameter 
     The ac-BarringForSpecialAC parameter denotes service access barring for a specific access. For example, a service access to a related service is barred if all of information of special AC 11 . . . 15 stored in a Universal Subscriber Identity Module (USIM) of a UE and a value of an AC-BarringConfig parameter received through the SIB Type2 message are set to “1”. 
     For example, if a UE receives the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter and the ac-BarringForCSFB-r10 parameter through the SIB Type2 message upon accessing an eNB, it will be assumed that the UE may detect access barring for a related service using a value of each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter and the ac-BarringForCSFB-r10 parameter. 
     The eNB  113  may bar a service access to the eNB  113  of UEs using an access Barring For MultiMedia TELephony-Voice-Release 9 (ssac-BarringForMMTEL-Voice-r9) parameter indicating a service access barring for multimedia telephony-voice-Release 9 and an access Barring For MultiMedia TELephony-Video-Release 9 (ssac-BarringForMMTEL-Video-r9) parameter indicating a service access barring for multimedia telephony-video-Release 9. The ssac-BarringForMMTEL-Voice-r9 parameter and the ssac-BarringForMMTEL-Video-r9 parameter are processed in an upper layer, not a RRC layer, for example, a User Interface (UI) layer. 
     Each of the ssac-BarringForMMTEL-Voice-r9 parameter and the ssac-BarringForMMTEL-Video-r9 parameter may indicate related service access barring by transmitting/receiving the ssac-BarringForMMTEL-Voice-r9 parameter and the ssac-BarringForMMTEL-Video-r9 parameter. On the other hand, a value of each of the ssac-BarringForMMTEL-Voice-r9 parameter and the ssac-BarringForMMTEL-Video-r9 parameter may indicate the related service access barring. For example, if each of the ssac-BarringForMMTEL-Voice-r9 parameter and the ssac-BarringForMMTEL-Video-r9 parameter is implemented by 1 bit, it will be assumed that each of the ssac-BarringForMMTEL-Voice-r9 parameter and the ssac-BarringForMMTEL-Video-r9 parameter indicates the related service access barring only if a value of each of the ssac-BarringForMMTEL-Voice-r9 parameter and the ssac-BarringForMMTEL-Video-r9 parameter is “1”. 
     In  FIG.  1   , for convenience, the eNB bars a service access for the eNB using ac-BarringInfo processed in a RRC layer. 
     The eNB  113  includes the generated ac-BarringInfo into System Information (SI), and broadcasts a SIB Type2 message including the SI including the ac-BarringInfo in order for UEs located in a service coverage area of the eNB  113  to receive the SIB Type2 message in step  117 . In  FIG.  1   , the UE  111  receives the SIB Type2 message broadcast by the eNB  113 , however, it will be understood by those of ordinary skill in the art that UEs which receive the SIB Type2 message may be all UEs located in the service coverage of the eNB  113 . 
     The UE  111  receives the SIB Type2 message, detects the ac-BarringInfo from the SI included in the received SIB Type2 message, and stores the detected ac-BarringInfo in step  119 . 
     The UE  111  detects that a PS Voice Call has been triggered in step  121 . Upon detecting that the PS Voice Call has been triggered, the UE  111  determines whether the UE  111  may perform a service access to the eNB  113  for the PS Voice Call by checking the ac-BarringInfo in step  123 . In  FIG.  1   , the UE  111  may detect that the service access to the eNB  113  is barring since the ac-BarringInfo includes the ac-BarringForMo-Data parameter. 
     According to detecting the service barring for the PS Voice Call, the UE  111  intends to service access the eNB  113  by transmitting a RRC Connection Request message to the eNB  113  after waiting for a preset time in step  125 . 
       FIG.  2    illustrates an operation process of an eNB, such as the eNB  113  illustrated in  FIG.  1   , according to an exemplary embodiment of the present invention. 
     Referring to  FIG.  2   , the eNB  113  generates ac-BarringInfo upon determining that there is a need for service access barring by considering system parameters in step  211 . The ac-BarringInfo is described before with reference to  FIG.  1   , so a detailed description thereof will be omitted here. The eNB  113  includes the generated ac-BarringInfo into SI, and broadcasts an SIB Type2 message including the SI including the ac-BarringInfo in order for UEs (including a UE  111 ) located in a service coverage area of the eNB  113  to receive the SIB Type2 message in step  213 . The eNB  113  receives a RRC Connection Request message from the UE  111  in step  215 . It is noted that the UE  111  transmits the RRC Connection Request message after waiting for a preset time according to the service access barring of the eNB  113 . 
       FIG.  3    illustrates an operation process of a UE, such as the UE  111  illustrated in  FIG.  1   , according to an exemplary embodiment of the present invention. 
     Referring to  FIG.  3   , the UE  111  receives an SIB Type2 message including SI including ac-BarringInfo from eNB  113  in step  311 . The UE  111  detects the ac-BarringInfo from the SI included in the SIB Type2 message and stores the ac-BarringInfo in step  313 . The UE  111  detects that a PS Voice Call is triggered in step  315 . The UE  111  determines whether the UE  111  may perform a service access to the eNB  113  for the PS Voice Call by checking the stored ac-BarringInfo in step  317 . In  FIG.  1   , it will be assumed that the ac-BarringInfo includes the ac-BarringForMo-Data parameter, so the UE  111  may detect that the service access to the eNB  113  is barring. 
     The UE  111  transmits a RRC Connection message for the PS Voice Call to the eNB  113  after waiting for a preset time without transmitting the RRC Connection message for the PS Voice Call due to the service access barring in step  319 . 
     As described with regard to  FIGS.  1  to  3   , in an LTE mobile communication system, a specific eNB may bar a service access to the specific eNB using an ac-BarringInfo. 
     Meanwhile, whether a voice call service is possible is very important for a user using a UE, so a mobile communication provider gives the highest service priority to the voice call service by considering importance of the voice call service. That is, the user may receive the voice call service anytime and anywhere. 
     In an LTE mobile communication system, if an eNB controls to service access the eNB using ac-BarringInfo including an ac-BarringForMo-Data parameter, a voice call service becomes a service access barring object for the eNB due to the ac-BarringForMo-Data parameter, because the voice call service is provided as a packet data service, that is, the voice call service is provided through packet data. For example, in the LTE mobile communication system, if the eNB controls to service access the eNB using a scheme described in  FIGS.  1  to  3   , a voice call service may not be provided to a UE during an access barring interval. 
     Exemplary embodiments of the present invention further provide an apparatus, circuit, and method for controlling a service access using a new parameter, i.e., an Access Enable For PS Voice Call (AccessEnableForPSCall) parameter indicating that a service access to a PS Voice Call is possible in an LTE mobile communication system. The AccessEnableForPSCall parameter may be included in the ac-BarringInfo. 
       FIG.  4    schematically illustrates a process for controlling a PS Voice Call access in an LTE mobile communication system according to a second exemplary embodiment of the present invention. 
     Referring to  FIG.  4   , an eNB  413  generates ac-BarringInfo upon determining that there is a need for service access barring by considering system parameters in step  415 . The ac-BarringInfo indicates information on a service access which the eNB  413  intends to bar, and includes at least one of an ac-BarringForEmergency parameter, an ac-BarringForMo-Signalling parameter, an ac-BarringForMo-Data parameter, an ac-BarringForCSFB-r10 parameter, and an AccessEnableForPSCall parameter. The BarringInfo is processed in a RRC layer. In  FIG.  4   , it will be assumed that the ac-BarringInfo includes all of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, the ac-BarringForCSFB-r10 parameter, and the AccessEnableForPSCall parameter. 
     Each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, the ac-BarringForCSFB-r10, and the AccessEnableForPSCall parameter may indicate related service access barring if each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, the ac-BarringForCSFB-r10 parameter, and the AccessEnableForPSCall parameter is included in the ac-BarringInfo. On the other hand, each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, the ac-BarringForCSFB-r10 parameter, and the AccessEnableForPSCall parameter may indicate the related service access barring according to a parameter value of each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, the ac-BarringForCSFB-r10 parameter, and the AccessEnableForPSCall parameter. For example, in a case that each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, the ac-BarringForCSFB-r10 parameter, and the AccessEnableForPSCall parameter is implemented by 1 bit, it will be assumed that a related parameter indicates the service access barring for the related service only if a parameter value of a related parameter is ‘1’. 
     The eNB  413  may bar a service access to the eNB of UEs using an ssac-BarringForMMTEL-Voice-r9 parameter and an ssac-BarringForMMTEL-Video-r9 parameter processed in an upper layer, not the RRC layer, e.g., a User Interface (UI) layer. 
     Each of the ssac-BarringForMMTEL-Voice-r9 parameter and the ssac-BarringForMMTEL-Video-r9 parameter may indicate related service access barring if each of the ssac-BarringForMMTEL-Voice-r9 parameter and the ssac-BarringForMMTEL-Video-r9 parameter is included in the ac-BarringInfo. On the other hand, each of the ssac-BarringForMMTEL-Voice-r9 parameter and the ssac-BarringForMMTEL-Video-r9 parameter may indicate the related service access barring according to a parameter value of each of the ssac-BarringForMMTEL-Voice-r9 parameter, and the ssac-BarringForMMTEL-Video-r9 parameter. For example, in a case that each of the ssac-BarringForMMTEL-Voice-r9 parameter and the ssac-BarringForMMTEL-Video-r9 parameter is implemented by 1 bit, it will be assumed that a related parameter indicates service access barring for a related service only if a parameter value of the related parameter is ‘1’. 
     In  FIG.  4   , for convenience, the eNB bars a service access for the eNB using ac-BarringInfo processed in a RRC layer. 
     The eNB  413  includes the generated ac-BarringInfo into SI, and broadcasts an SIB Type2 message including the SI including the ac-BarringInfo in order for UEs located in a service coverage area of the eNB  413  to receive the SIB Type2 message in step  417 . In  FIG.  4   , the UE  411  receives the SIB Type2 message broadcast by the eNB  413 . However, it will be understood by those of ordinary skill in the art that UEs which receive the SIB Type2 message may be all UEs located in the service coverage area of the eNB  413 . 
     The UE  411  receives the SIB Type2 message, detects the ac-BarringInfo from the SI included in the received SIB Type2 message, and stores the detected ac-BarringInfo in step  419 . 
     The UE  411  detects that a PS Voice Call is triggered in step  421 . Upon detecting that the PS Voice Call is triggered, the UE  411  determines whether the UE  411  may perform a service access to the eNB  413  for the PS Voice Call by checking the ac-BarringInfo in step  423 . In  FIG.  4   , the UE  411  may detect that a service access to the PS Voice Call is possible even though a service access to the eNB  413  is barring since the ac-BarringInfo includes the ac-BarringForMo-Data parameter and the AccessEnableForPSCall parameter. 
     According to detecting that the service access to the PS Voice Call is possible, the UE  411  intends to service access the eNB  413  by transmitting a RRC Connection Request message to the eNB  413  in step  425 . 
       FIG.  5    illustrates an operation process of an eNB, such as the eNB  413  illustrated in  FIG.  4   , according to an exemplary embodiment of the present invention. 
     Referring to  FIG.  5   , the eNB  413  generates ac-BarringInfo upon determining that there is a need for service access barring by considering system parameters in step  511 . The ac-BarringInfo is described before with reference to  FIG.  4   , so a detailed description thereof will be omitted here. The eNB  413  includes the generated ac-BarringInfo into SI, and broadcasts an SIB Type2 message including the SI including the ac-BarringInfo, specially an AccessEnableForPSCall parameter in order for UEs (including a UE  411 ) located in a service coverage of the eNB  413  to receive the SIB Type2 message in step  513 . The eNB  413  receives a RRC Connection Request message from the UE  411  in step  515 . It is noted that the UE  411  immediately transmits the RRC Connection Request message to the eNB  413  without service access barring by detecting the AccessEnableForPSCall parameter. 
       FIG.  6    illustrates an operation process of a UE, such as the UE  411  illustrated in  FIG.  4   , according to an exemplary embodiment of the present invention. 
     Referring to  FIG.  6   , the UE  411  receives an SIB Type2 message including SI including ac-BarringInfo including an AccessEnableForPSCall parameter from eNB  413  in step  611 . The UE  411  detects the ac-BarringInfo including the AccessEnableForPSCall parameter from the SI included in the SIB Type2 message and stores the ac-BarringInfo in step  613 . The UE  411  detects that a PS Voice Call is triggered in step  615 . The UE  411  determines whether the UE  411  may perform a service access to the eNB  113  for the PS Voice Call by checking the stored ac-BarringInfo in step  617 . In  FIG.  4   , it will be assumed that the ac-BarringInfo includes the ac-BarringForMo-Data parameter and the AccessEnableForPSCall parameter, so the UE  411  may detect that the service access to the eNB  413  is possible. So, the UE  411  transmits a RRC Connection message for the PS Voice Call to the eNB  413  since the service access to the eNB  413  is possible in step  619 . 
     As described with regard to  FIGS.  4  to  6   , in an LTE mobile communication system, an eNB may provide a voice call service by including the AccessEnableForPSCall parameter into the ac-BarringInfo. 
     Referring to  FIGS.  4  to  6   , a service type of a service which is always possible to service access in a case that a service access to a specific eNB is barred in an LTE mobile communication system is a voice call service. However, it will be understood by those of ordinary skill in the art that a service access control process described in  FIGS.  4  to  6    may be applied to other service different from the voice call service. 
     Further, it will be understood by those of ordinary skill in the art that the service type of the service which is always possible to service access in the case that the service access to the specific eNB is barred in the LTE mobile communication system may not be limited, and may, for example, be one of a real-time service such as the voice call service, a service that a UE will always want to receive, a service which is set to always serve in the LTE mobile communication system, a service which is provided to a UE which uses the highest billing rate, etc. That is, the service type of the service which is always possible to service access in the case that the service access to the specific eNB is barred in the LTE mobile communication system may be determined by considering a service type, a service priority, etc. 
     In  FIGS.  4  to  6   , a service access to a specific eNB is controlled by facilitating a service access to a voice call service in the case that the service access to the specific eNB is barred in the LTE mobile communication system. However, it will be understood by those of ordinary skill in the art that a service access may be controlled per a service, and a service characteristic without limiting a service access based on whether a service is the voice call service. 
     The detailed description of a method for controlling a service access using a service characteristic will follow. 
     Each of services has a related service characteristic. For example, the related service characteristic may include data transmission capacity, response/delay speed, data reliability, and a real-time communication characteristic such as a voice, a video conference, and a video call. So, an eNB may control a service access based on the service characteristic. That is, the eNB may control a service access according to a service characteristic of a related service regardless of a type of a service which a UE wants to receive. 
     For example, an eNB always allows a service access if a service characteristic has a real-time communication characteristic regardless of a service type. On the other hand, the eNB bars the service access if the service characteristic does not have the real-time communication characteristic regardless of the service type. The eNB always allows the service access if the service characteristic indicates a response/delay speed is less than a preset threshold response/delay speed regardless of the service type. On the other hand, the eNB bars the service access if the service characteristic does not indicate the response/delay speed is equal to or greater than the threshold response/delay speed regardless of the service type. Further, the eNB always allows the service access if a data transmitting capacity is less than a preset threshold data transmitting capacity regardless of the service type. On the other hand, the eNB bars the service access if the data transmitting capacity is equal to or greater than the threshold data transmitting capacity regardless of the service type. 
     That is, the eNB may bar or allow a service access on a basis of a service characteristic including data transmission capacity, response/delay speed, data reliability, and a real-time communication characteristic such as a voice, a video conference, and a video call. 
     In  FIGS.  4  to  6   , in an LTE mobile communication system, a specific eNB allows a service access to a voice call service even though a service access to the specific eNB is barring. However, it will be understood by those of ordinary skill in the art that exemplary embodiments of the present invention may bar a service access by including a voice call service, i.e., a PS Voice Call into Mobile Originating (MO) data. 
     Exemplary embodiments of the present invention further provide an apparatus, circuit, and method for controlling a service access using an AccessEnableGroup parameter indicating an Access Enable Group (AccessEnableGroup) as a group of UEs which may service access under a service access barring situation in an LTE mobile communication system. The AccessEnableGroup parameter includes IDentifiers (IDs) of UEs included in an AccessEnableGroup. The AccessEnableGroup parameter may be included in the ac-BarringInfo. 
       FIG.  7    illustrates a process for controlling a PS Voice Call access in an LTE mobile communication system according to a third exemplary embodiment of the present invention. 
     Referring to  FIG.  7   , an eNB  713  generates ac-BarringInfo upon determining that there is a need for service access barring by considering system parameters in step  715 . The ac-BarringInfo indicates information on a service access which the eNB  713  intends to bar, and includes at least one of an ac-BarringForEmergency parameter, an ac-BarringForMo-Signalling parameter, an ac-BarringForMo-Data parameter, an ac-BarringForCSFB-r10 parameter, and an Access Enable Group parameter. The ac-BarringInfo is processed in a RRC layer. In  FIG.  7   , it will be assumed that the ac-BarringInfo includes all of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, the ac-BarringForCSFB-r10 parameter, and the Access Enable Group parameter. In  FIG.  7   , it will be further assumed that the Access Enable Group parameter includes an ID of the UE  711 . 
     Each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 may indicate related service access barring if each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter is included in the ac-BarringInfo. On the other hand, each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter may indicate the related service access barring according to a parameter value of each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter. For example, in a case that each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter is implemented by 1 bit, it will be assumed that a related parameter indicates the service access barring for the related service only if a parameter value of the related parameter is ‘1’. 
     The eNB  713  may bar a service access to the eNB of UEs using an ssac-BarringForMMTEL-Voice-r9 parameter and an ssac-BarringForMMTEL-Video-r9 parameter processed in an upper layer not the RRC layer, e.g., a UI layer. 
     Each of the ssac-BarringForMMTEL-Voice-r9 parameter, and the ssac-BarringForMMTEL-Video-r9 parameter may indicate related service access barring if each of the ssac-BarringForMMTEL-Voice-r9 parameter, and the ssac-BarringForMMTEL-Video-r9 parameter is included in the ac-BarringInfo. On the other hand, each of the ssac-BarringForMMTEL-Voice-r9 parameter, and the ssac-BarringForMMTEL-Video-r9 parameter may indicate the related service access barring according to a parameter value of each of the ssac-BarringForMMTEL-Voice-r9 parameter, and the ssac-BarringForMMTEL-Video-r9 parameter. For example, in a case that each of the ssac-BarringForMMTEL-Voice-r9 parameter, and the ssac-BarringForMMTEL-Video-r9 parameter is implemented by 1 bit, it will be assumed that a related parameter indicates the service access barring for the related service only if a parameter value of the related parameter is ‘1’. 
     In  FIG.  7   , for convenience, the eNB bars a service access for the eNB using ac-BarringInfo processed in a RRC layer. 
     The eNB  713  includes the generated ac-BarringInfo into SI, and broadcasts an SIB Type2 message including the SI including the ac-BarringInfo in order for UEs located in a service coverage area of the eNB  713  to receive the SIB Type2 message in step  717 . In  FIG.  7   , the UE  711  receives the SIB Type2 message broadcasted by the eNB  713 , however, it will be understood by those of ordinary skill in the art that UEs which receive the SIB Type2 message may be all UEs located in the service coverage area of the eNB  713 . 
     The UE  711  receives the SIB Type2 message, detects the ac-BarringInfo from the SI included in the received SIB Type2 message, and stores the detected ac-BarringInfo in step  719 . 
     The UE  711  detects that a PS Voice Call is triggered in step  721 . Upon detecting that the PS Voice Call is triggered, the UE  711  determines whether the UE  711  may perform a service access to the eNB  713  for the PS Voice Call by checking the ac-BarringInfo in step  723 . In  FIG.  7   , the UE  711  may detect that a service access to the eNB  713  is possible even though a service access to the eNB  713  is barring since the ac-BarringInfo includes the ac-BarringForMo-Data parameter and the Access Enable Group parameter, and the Access Enable Group parameter includes the ID of the UE  711 . 
     According to detecting that the service access to the PS Voice Call is possible, the UE  711  intends to service access the eNB  713  by transmitting a RRC Connection Request message to the eNB  713  in step  725 . 
       FIG.  8    illustrates an operation process of an eNB, such as the eNB  713  illustrated in  FIG.  7   , according to an exemplary embodiment of the present invention. 
     Referring to  FIG.  8   , the eNB  713  generates ac-BarringInfo upon determining that there is a need for service access barring by considering system parameters in step  811 . The ac-BarringInfo is described before with reference to  FIG.  7   , so a detailed description thereof will be omitted here. The eNB  713  includes the generated ac-BarringInfo into SI, and broadcasts an SIB Type2 message including the SI including the ac-BarringInfo, specially an Access Enable Group parameter in order for UEs (including a UE  711 ) located in a service coverage of the eNB  713  to receive the SIB Type2 message in step  813 . The eNB  713  receives a RRC Connection Request message from the UE  711  in step  815 . It is noted that the UE  711  immediately transmits the RRC Connection Request message to the eNB  713  without service access barring by detecting the Access Enable Group parameter. 
       FIG.  9    illustrates an operation process of a UE, such as the UE  711  illustrated in  FIG.  7   , according to an exemplary embodiment of the present invention. 
     Referring to  FIG.  9   , the UE  711  receives an SIB Type2 message including SI including ac-BarringInfo including an Access Enable Group parameter from eNB  713  in step  911 . The UE  711  detects the ac-BarringInfo including the Access Enable Group parameter from the SI included in the SIB Type2 message and stores the ac-BarringInfo in step  913 . The UE  711  detects that a PS Voice Call is triggered in step  915 . The UE  711  determines whether the UE  711  may perform a service access to the eNB  713  for the PS Voice Call by checking the stored ac-BarringInfo in step  917 . In  FIG.  7   , the ac-BarringInfo includes the ac-BarringForMo-Data parameter and the Access Enable Group parameter, so the UE  711  may detect that the service access to the eNB  713  is possible. 
     The UE  711  transmits a RRC Connection message for the PS Voice Call to the eNB  713  since the service access to the eNB  713  is possible in step  919 . 
     As described with regard to  FIGS.  7  to  9   , in an LTE mobile communication system, an eNB may provide a voice call service by including the Access Enable Group parameter into the ac-BarringInfo anytime and anywhere. 
     In  FIGS.  7  to  9   , a service type of a service which is always possible to service access in a case that a service access to a specific eNB is barred in an LTE mobile communication system is a voice call service. However, it will be understood by those of ordinary skill in the art that a service access control process described in  FIGS.  7  to  9    may be applied to other service different from the voice call service. The detailed description of the service type of the service which is always possible to service access in the case that the service access to the specific eNB is barred in the LTE mobile communication system will be omitted. 
     Unlike  FIGS.  7  to  9   , exemplary embodiments of the present invention further propose an apparatus, circuit, and method for controlling a service access using a Service Access Enable (ServiceAccessEnable) parameter indicating that a service which is always possible to service access in a case that a service access to a specific eNB is barred in an LTE mobile communication system. 
     In  FIGS.  7  to  9   , a service access to a specific eNB is controlled by facilitating a service access to a voice call service in the case that the service access to the specific eNB is barred in the LTE mobile communication system. However, it will be understood by those of ordinary skill in the art that a service access may be controlled per a service, and a service characteristic without limiting a service access based on whether a service is the voice call service. 
     The description of a method for controlling a service access using a service characteristic will follow. 
     Each of services has a service characteristic, and the service characteristic may include data transmitting capacity, response/delay speed, data reliability, and a real-time communication characteristic such as a voice, a video conference, and a video call. So, an eNB may control a service access based on the service characteristic. That is, the eNB may control a service access according to a service characteristic of a related service regardless of a service type of the related service which a UE intends to receive. 
     For example, an eNB always allows a service access if a service characteristic has a real-time communication characteristic regardless of a service type. On the other hand, the eNB bars the service access if the service characteristic does not have the real-time communication characteristic regardless of the service type. The eNB always allows the service access if the service characteristic indicates a response/delay speed is less than a preset threshold response/delay speed regardless of the service type. On the other hand, the eNB bars the service access if the service characteristic does not indicate the response/delay speed is equal to or greater than the threshold response/delay speed regardless of the service type. Further, the eNB always allows the service access if a data transmitting capacity is less than a preset threshold data transmitting capacity regardless of the service type. On the other hand, the eNB bars the service access if the data transmitting capacity is equal to or greater than the threshold data transmitting capacity regardless of the service type. 
     That is, the eNB may bar or allow a service access on a basis of a service characteristic including data transmission capacity, response/delay speed, data reliability, and a real-time communication characteristic such as a voice, a video conference, and a video call. 
     In  FIGS.  7  to  9   , a service access to a specific eNB is controlled by facilitating a service access to a voice call service in the case that the service access to the specific eNB is barred in the LTE mobile communication system. However, it will be understood by those of ordinary skill in the art that a service access may be barred by including a voice call service, i.e., a PS Voice Call into an MO data. 
       FIG.  10    illustrates a process for controlling a PS Voice Call access in an LTE mobile communication system according to a fourth exemplary embodiment of the present invention. 
     Referring to  FIG.  10   , an eNB  1013  generates ac-BarringInfo upon determining that there is a need for service access barring by considering system parameters in step  1015 . The ac-BarringInfo indicates information on a service access which the eNB  1013  intends to bar, and includes at least one of an ac-BarringForEmergency parameter, an ac-BarringForMo-Signalling parameter, an ac-BarringForMo-Data parameter, and an ac-BarringForCSFB-r10 parameter. The ac-BarringInfo is processed in a RRC layer. In  FIG.  10   , it will be assumed that the ac-BarringInfo includes all of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter. 
     Each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 may indicate related service access barring if each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter is included in the ac-BarringInfo. On the other hand, each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter may indicate the related service access barring according to a parameter value of each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter. For example, in a case that each of the ac-BarringForEmergency parameter, the ac-BarringForMo-Signalling parameter, the ac-BarringForMo-Data parameter, and the ac-BarringForCSFB-r10 parameter is implemented by 1 bit, it will be assumed that a related parameter indicates the service access barring for the related service only if a parameter value of the related parameter is ‘1’. 
     The eNB  1013  may bar a service access to the eNB of UEs using an ssac-BarringForMMTEL-Voice-r9 parameter and an ssac-BarringForMMTEL-Video-r9 parameter processed in an upper layer not the RRC layer, e.g., a UI layer. 
     Each of the ssac-BarringForMMTEL-Voice-r9 parameter, and the ssac-BarringForMMTEL-Video-r9 parameter may indicate related service access barring if each of the ssac-BarringForMMTEL-Voice-r9 parameter, and the ssac-BarringForMMTEL-Video-r9 parameter is included in the ac-BarringInfo. On the other hand, each of the ssac-BarringForMMTEL-Voice-r9 parameter, and the ssac-BarringForMMTEL-Video-r9 parameter may indicate the related service access barring according to a parameter value of each of the ssac-BarringForMMTEL-Voice-r9 parameter, and the ssac-BarringForMMTEL-Video-r9 parameter. For example, in a case that each of the ssac-BarringForMMTEL-Voice-r9 parameter, and the ssac-BarringForMMTEL-Video-r9 parameter is implemented by 1 bit, it will be assumed that a related parameter indicates the service access barring for the related service only if a parameter value of the related parameter is ‘1’. 
     In  FIG.  10   , for convenience, the eNB bars a service access for the eNB using ac-BarringInfo processed in a RRC layer. 
     The eNB  1013  includes the generated ac-BarringInfo into SI, and broadcasts an SIB Type2 message including the SI including the ac-BarringInfo in order for UEs located in a service coverage area of the eNB  1013  to receive the SIB Type2 message in step  1017 . In  FIG.  10   , the UE  1011  receives the SIB Type2 message broadcast by the eNB  1013 , however, it will be understood by those of ordinary skill in the art that UEs which receive the SIB Type2 message may be all UEs located in the service coverage area of the eNB  1013 . 
     The UE  1011  receives the SIB Type2 message, detects the ac-BarringInfo from the SI included in the received SIB Type2 message, and stores the detected ac-BarringInfo in step  1019 . 
     The UE  1011  detects that a PS Voice Call is triggered in step  1021 . Upon detecting that the PS Voice Call is triggered, the UE  1011  determines whether the UE  1011  may perform a service access to the eNB  1013  for the PS Voice Call by checking the ac-BarringInfo in step  1023 . In  FIG.  10   , the UE  1011  may detect that a service access to the eNB  1013  is possible since the ac-BarringInfo includes the ac-BarringForMo-Data parameter. On the other hand, the UE  1011  intends to service access the eNB  1013  by transmitting a RRC Connection Request message including a ServiceAccessEnable parameter to the eNB  1013  since the UE  1011  decides that the PS Voice Call should be served even though a service access is barring in step  1025 . A value of the ServiceAccessEnable parameter is set to a value indicating the PS Voice Call. 
     The eNB  1013  receives the RRC Connection Request message, and detects that the UE  1011  has intended to service access the eNB  1013  according to the PS Voice Call triggering by detecting the ServiceAccessEnable parameter form the RRC Connection Request message. 
       FIG.  11    illustrates an operation process of an eNB, such as the eNB  1013  illustrated in  FIG.  10   , according to an exemplary embodiment of the present invention. 
     Referring to  FIG.  11   , the eNB  1013  generates ac-BarringInfo upon determining that there is a need for a service access barring by considering system parameters in step  1111 . The ac-BarringInfo is described before with reference to  FIG.  10   , so a detailed description thereof will be omitted here. The eNB  1013  includes the generated ac-BarringInfo into SI, and broadcasts an SIB Type2 message including the SI including the ac-BarringInfo in order for UEs (including a UE  1011 ) located in a service coverage area of the eNB  1013  to receive the SIB Type2 message in step  1113 . The eNB  713  receives a RRC Connection Request message including a ServiceAccessEnable parameter from the UE  1011  in step  1115 . It is noted that the UE  1011  immediately transmits the RRC Connection Request message to the eNB  1013  without a service access barring according to a PS Voice Call triggering after determining that a PS Voice Call should be served in spite of service access barring of the eNB  1013 . 
       FIG.  12    illustrates an operation process of a UE, such as the UE  1011  illustrated in  FIG.  10   , according to an exemplary embodiment of the present invention. 
     Referring to  FIG.  12   , the UE  1011  receives an SIB Type2 message including SI including ac-BarringInfo including an Access Enable Group parameter from eNB  1013  in step  1211 . The UE  1011  detects the ac-BarringInfo from the SI included in the SIB Type2 message and stores the ac-BarringInfo in step  1213 . The UE  1011  detects that a PS Voice Call is triggered in step  1215 . The UE  1011  determines whether the UE  1011  may perform a service access to the eNB  1013  for the PS Voice Call by checking the stored ac-BarringInfo in step  1217 . In  FIG.  10   , the UE  1011  may detect that the service access to the eNB  1013  is barring and there is no service access barring for the PS Voice Call since the ac-BarringInfo includes the ac-BarringForMo-Data parameter. 
     The UE  1011  transmits a RRC Connection message including a ServiceAccessEnable parameter for the PS Voice Call to the eNB  1013  since there is no service access barring for the PS Voice Call in step  1219 . 
     As described with regard to  FIGS.  10  to  12   , in an LTE mobile communication system, a vice call service may be always provided anytime anywhere by including a ServiceAccessEnable parameter into a RRC Connection Request message. 
     In  FIGS.  10  to  12   , a service type of a service which is always possible to service access in a case that a service access to a specific eNB is barred in an LTE mobile communication system is a voice call service. However, it will be understood by those of ordinary skill in the art that a service access control process described in  FIGS.  10  to  12    may be applied to other service different from the voice call service. The detailed description of the service type of the service which is always possible to service access in the case that the service access to the specific eNB is barred in the LTE mobile communication system will be omitted. 
     In  FIGS.  10  to  12   , a service access to a specific eNB is controlled by facilitating a service access to a voice call service in the case that the service access to the specific eNB is barred in the LTE mobile communication system. However, it will be understood by those of ordinary skill in the art that a service access may be controlled per a service, and a service characteristic without limiting a service access based on whether a service is the voice call service. 
     The description of a method for controlling a service access using a service characteristic will follow. 
     Each of services has a service characteristic, and the service characteristic may include data transmitting capacity, response/delay speed, data reliability, and a real-time communication characteristic such as a voice, a video conference, and a video call. So, an eNB may control a service access based on the service characteristic. That is, the eNB may control a service access according to a service characteristic of a related service regardless of a service type of the related service which a UE intends to receive. 
     For example, an eNB always allows a service access if a service characteristic has a real-time communication characteristic regardless of a service type. On the other hand, the eNB bars the service access if the service characteristic does not have the real-time communication characteristic regardless of the service type. The eNB always allows the service access if the service characteristic indicates a response/delay speed is less than a preset threshold response/delay speed regardless of the service type. On the other hand, the eNB bars the service access if the service characteristic does not indicate the response/delay speed is equal to or greater than the threshold response/delay speed regardless of the service type. Further, the eNB always allows the service access if a data transmitting capacity is less than a preset threshold data transmitting capacity regardless of the service type. On the other hand, the eNB bars the service access if the data transmitting capacity is equal to or greater than the threshold data transmitting capacity regardless of the service type. 
     That is, the eNB may bar or allow a service access on a basis of a service characteristic including data transmission capacity, response/delay speed, data reliability, and a real-time communication characteristic such as a voice, a video conference, and a video call. 
     In  FIGS.  10  to  12   , a service access to a specific eNB is controlled by facilitating a service access to a voice call service in the case that the service access to the specific eNB is barred in the LTE mobile communication system. However, it will be understood by those of ordinary skill in the art that a service access may be barred by including a voice call service, i.e., a PS Voice Call into an MO data. 
       FIG.  13    illustrates an internal structure of a UE in an LTE communication system according to an exemplary embodiment of the present invention. 
     Referring to  FIG.  13   , a UE  1300  includes a receiver  1311 , a controller  1313 , a transmitter  1315 , and a storage unit  1317 . 
     The controller  1313  controls the overall operation of the UE  1300 . In particular, the controller  1313  controls the UE  1300  to perform an operation of service accessing an eNB according to the first exemplary embodiment to the fourth exemplary embodiment of the present invention. The service access operation is performed in the manner described before with reference to  FIGS.  1  to  12   , so a detailed description thereof will be omitted here. 
     The receiver  1311  receives signals from an eNB, etc. under the control of the controller  1313 . The signals received in the receiver  1311  are described before with reference to  FIGS.  1  to  12   , so a detailed description thereof will be omitted here. 
     The transmitter  1315  transmits signals to the eNB, etc. under the control of the controller  1313 . The signals transmitted in the transmitter  1315  are described before with reference to  FIGS.  1  to  12   , so a detailed description thereof will be omitted here. 
     The storage unit  1317  stores the signals received by the receiver  1311  and data for the operation of the UE  1300 , e.g., information related to the service access operation. 
     While the receiver  1311 , the controller  1313 , the transmitter  1315 , and the storage unit  1317  are shown in  FIG.  13    as separate units, it is to be understood that this is for merely convenience of description. In other words, two or more of the receiver  1311 , the controller  1313 , the transmitter  1315 , and the storage unit  1317  may be incorporated into a single unit. 
       FIG.  14    illustrates an internal structure of an eNB in an LTE communication system according to an exemplary embodiment of the present invention. 
     Referring to  FIG.  14   , an eNB  1400  includes a receiver  1411 , a controller  1413 , a transmitter  1415 , and a storage unit  1417 . 
     The controller  1413  controls the overall operation of the eNB  1400 . In particular, the controller  1413  controls the eNB  1400  to perform an operation related to a service access operation in a UE according to the first exemplary embodiment to the fourth exemplary embodiment of the present invention. The operation related to the service access operation in the UE is performed in the manner described before with reference to  FIGS.  1  to  12   , so a detailed description thereof will be omitted here. 
     The receiver  1411  receives signals from the UE, etc. under a control of the controller  1413 . The signals received in the receiver  1411  are described before with reference to  FIGS.  1  to  12   , so a detailed description thereof will be omitted here. 
     The transmitter  1415  transmits signals to the UE, etc. under a control of the controller  1413 . The signals transmitted in the transmitter  1415  are described before with reference to  FIGS.  1  to  12   , so a detailed description thereof will be omitted here. 
     The storage unit  1417  stores the signals received by the receiver  1411  and data for an operation of the eNB  1400 , e.g., information related to the service access operation in the UE. 
     While the receiver  1411 , the controller  1413 , the transmitter  1415 , and the storage unit  1417  are shown in  FIG.  14    as separate units, it is to be understood that this is for merely convenience of description. In other words, two or more of the receiver  1411 , the controller  1413 , the transmitter  1415 , and the storage unit  1417  may be incorporated into a single unit. 
     As is apparent from the foregoing description, exemplary embodiments of the present invention enable to control a service access by considering at least one of a service type and a service priority in a packet data communication system. 
     Exemplary embodiments of the present invention enable control of a service access by considering a service characteristic in a packet data communication system. 
     Exemplary embodiments of the present invention enable a seamless service access by considering a characteristic of a service provided to a UE in a case that an eNB bars a service in a packet data communication system. 
     Exemplary embodiments of the present invention enhance a service quality of a service provided in a packet data communication system by facilitating a seamless service access in the packet data communication system. 
     Exemplary embodiments of the present invention enhance performance of a service access control function provided in a packet data communication system by facilitating that a service access control is performed by considering a service characteristic. 
     While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.