Patent Publication Number: US-11382147-B2

Title: UE, MME, communication control method of UE, and communication control method of MME

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a Continuation of copending application Ser. No. 16/728,237, filed on Dec. 27, 2019, which is a Continuation of application Ser. No. 15/774,923, filed on May 9, 2018, now U.S. Pat. No. 10,531,501, issued Jan. 7, 2020, which is a 35 U.S.C. 371 National Stage Application of International Application No. PCT/JP2016/083365 filed on Nov. 10, 2016, which claims the benefit under 35 U.S.C. § 119(a) to Patent Application No. 2015-220105, filed in Japan on Nov. 10, 2015, all of which are hereby expressly incorporated by reference into the present application. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a UE, an MME, a communication control method of a UE, and a communication control method of an MME. This application claims priority based on JP 2015-220105 filed on Nov. 10, 2015 in Japan, the contents of which are incorporated herein in its entirety by reference. 
     BACKGROUND ART 
     The 3rd Generation Partnership Project (3GPP), which undertakes activities for standardizing recent mobile communication systems, discusses System Architecture Enhancement (SAE), which is system architecture of the Long Term Evolution (LTE). 3GPP is in the process of creating specifications for the Evolved Packet System (EPS), which realizes an all-IP architecture. Note that a core network of LTE is called an Evolved Packet Core (EPC). 
     Furthermore, 3GPP recently discusses a Machine to Machine (M2M) communication technology. Note that the M2M communication may be machine-machine type communication. 3GPP discusses a Cellular Internet of Things (CIoT), in particular, as a technology for supporting Internet of Things (IoT) in a cellular network of 3GPP. 
     The IoT includes a mobile phone terminal such as a smartphone, and indicates various IT devices such as a personal computer and a sensor device. In CIoT technical problems for connecting such various terminal devices to a cellular network are extracted, and solutions are standardized. 
     For example, CIoT is demanded to optimize communication procedures for a terminal needed to increase the efficiency of power consumption so that a battery can be maintained for several years, to cope with communication in an indoor or underground state, and to provide connectivity to a large amount of terminals produced by inexpensive mass production. Furthermore, in CIoT, supporting low data rate communication with a simple end node is cited as a required condition. 
     Note that terminals allowed to connect to a 3GPP core network are referred to CIoT terminals herein. 
     CITATION LIST 
     Non Patent Literature 
     NPL 1: 3rd Generation Partnership Project: Technical Specification Group Services and System Aspects; Architecture enhancements for Cellular Internet of Things; (Release 13) 
     SUMMARY OF INVENTION 
     Technical Problem 
     As for CIoT, in order to increase the efficiency of a control signal, including a function unit having multiple functions in the core network is discussed. Specifically, providing a CIoT Serving Gateway Node (C-SGN) responsible for functions of known MME, SGW, and PGW in the core network is discussed. 
     3GPP discusses that a CIoT terminal is connected to the core network through an access network of CIoT. 
     Note that the core network to which the CIoT terminal is connected may be a known core network accommodating mobile phone terminals such as smartphones, may be a logically-divided core network for accommodating CIoT terminals, or may be a core network physically different from the known core network. However, a connection method to these core networks and a procedure for data transmission and/or reception to/from these core networks have not been made clear. 
     The present invention has been made in view of the above described situations, and an object is to provide a communication procedure such as an attach procedure suitable for a CIoT terminal. 
     Solution to Problem 
     In order to achieve the above-described object, a User Equipment (UE) according to one aspect of the present invention includes: a transmission and/or reception unit configured to perform an attach procedure; and a control unit. In the attach procedure, the transmission and/or reception unit is configured to: transmit an attach request message to a Mobility Management Entity (MME); be capable of receiving, as a response to the attach request message, an attach accept message or an attach reject message from the MME; and notify that the UE supports a mode A and the UE requests the mode A, based on transmission of the attach request message, the attach accept message includes network capability information indicating that the mode A is supported, the attach reject message includes network capability information indicating that the mode A is not supported, the control unit is configured to: interpret that the mode A is accepted by receiving the network capability information indicating that the mode A is supported, in a case that the attach accept message is received; and be capable of performing at least a first process after completion of the attach procedure, based on acceptance of the mode A, and the first process is a process for entering an idle mode to keep a UE context in a case that a message to suspend an RRC connection is received from a base station device. 
     A Mobility Management Entity (MME) according to one aspect of the present invention includes: a transmission and/or reception unit configured to perform an attach procedure; and a control unit. In the attach procedure, the transmission and/or reception unit is configured to: receive an attach request message from a User Equipment (UE), be capable of transmitting, as a response to the attach request message, an attach accept message or an attach reject message; acquire that the UE supports a mode A and the UE requests the mode A, based on reception of the attach request message; transmit to the UE the attach accept message including network capability information indicating that the mode A is supported, in a case of accepting the attach request message; and transmit to the UE the attach reject message including network capability information indicating that the mode A is not supported, in a case of rejecting the attach request message, the network capability information included in the attach accept message and indicating that the mode A is supported is used by the UE for interpreting that the mode A is accepted, and the control unit is capable of performing at least a first process after completion of the attach procedure, based on acceptance of the mode A, and the first process is a process for entering an idle mode to keep a bearer context in a case that an S1AP message is received from a base station device. 
     A communication control method for a User Equipment (UE) according to one aspect of the present invention includes: a transmission and/or reception step performing an attach procedure; and a control step. In the attach procedure, the transmission and/or reception step includes: transmitting an attach request message to a Mobility Management Entity (MME), being capable of receiving, as a response to the attach request message, an attach accept message or an attach reject message from the MME, and notifying that the UE supports a mode A and the UE requests the mode A, based on transmission of the attach request message, the attach accept message includes network capability information indicating that the mode A is supported, and the attach reject message includes network capability information indicating that the mode A is not supported. The control step includes: interpreting that the mode A is accepted by receiving the network capability information indicating that the mode A is supported, in a case that the attach accept message is received, and being capable of performing at least a first process after completion of the attach procedure, based on acceptance of the mode A, and the first process is a process for entering an idle mode to keep a UE context in a case that a message to suspend an RRC connection is received from a base station device. 
     A communication control method for a Mobility Management Entity (MME), the communication control method including: a transmission and/or reception step performing an attach procedure; and a control step. In the attach procedure, the transmission and/or reception step includes: receiving an attach request message from a User Equipment (UE); being capable of transmitting, as a response to the attach request message, an attach accept message or an attach reject message; acquiring that the UE supports a mode A and the UE requests the mode A, based on reception of the attach request message, transmitting to the UE the attach accept message including network capability information indicating that the mode A is supported, in a case of accepting the attach request message, and transmitting to the UE the attach reject message including network capability information indicating that the mode A is not supported, in a case of rejecting the attach request message. The network capability information included in the attach accept message and indicating that the mode A is supported is used by the UE for interpreting that the mode A is accepted, and the control step is capable of performing at least a first process after completion of the attach procedure, based on acceptance of the mode A, and the first process is a process for entering an idle mode to keep a bearer context in a case that an S Application Protocol (S1AP) message is received from a base station device. 
     Advantageous Effects of Invention 
     According to the present invention, a CIoT terminal can attach and/or detach a core network which can provide multiple transmission methods including a user data transmission method optimized for the CIoT terminal, to communicate with the core network. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram illustrating an overview of a mobile communication system. 
         FIG. 2  is a diagram illustrating an example of a configuration of an IP mobile communication network, and the like. 
         FIG. 3  is a diagram illustrating an example of a configuration of an IP mobile communication network, and the like. 
         FIG. 4  is a diagram illustrating a device configuration of an eNB. 
         FIG. 5  is a diagram illustrating a network initiated detach procedure. 
         FIG. 6  is a diagram illustrating a device configuration of an MME. 
         FIG. 7  is a diagram illustrating a storage unit of the MME. 
         FIG. 8  is a diagram illustrating the storage unit of the MME. 
         FIG. 9  is a diagram illustrating the storage unit of the MME. 
         FIG. 10  is a diagram illustrating the storage unit of the MME. 
         FIG. 11  is a diagram illustrating the storage unit of the MME. 
         FIG. 12  is a diagram illustrating the storage unit of the MME. 
         FIG. 13  is a diagram illustrating a device configuration of a SGW. 
         FIG. 14  is a diagram illustrating a storage unit of the SGW. 
         FIG. 15  is a diagram illustrating the storage unit of the SGW. 
         FIG. 16  is a diagram illustrating a device configuration of a PGW. 
         FIG. 17  is a diagram illustrating a storage unit of the PGW. 
         FIG. 18  is a diagram illustrating the storage unit of the PGW. 
         FIG. 19  is a diagram illustrating a device configuration of a C-SGN. 
         FIG. 20  is a diagram illustrating a device configuration of a UE. 
         FIG. 21  is a diagram illustrating a storage unit of the UE. 
         FIG. 22  is a diagram illustrating an overview of a communication procedure. 
         FIG. 23  is a diagram illustrating a first attach procedure. 
         FIG. 24  is a diagram illustrating a second attach procedure. 
         FIG. 25  is a diagram illustrating a third attach procedure. 
         FIG. 26  is a diagram illustrating a first transmission and/or reception procedure. 
         FIG. 27  is a diagram illustrating a second transmission and/or reception procedure. 
         FIG. 28  is a diagram illustrating a UE initiated detach procedure. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, a preferred embodiment for carrying out the present invention will be described with reference to the drawings. Note that as an example, the present embodiment describes an embodiment of a mobile communication system to which the present invention is applied. 
     1. EMBODIMENTS 
     1.1. System Overview 
       FIG. 1  is a diagram illustrating an overview of a mobile communication system according to the present embodiment. As illustrated in  FIG. 1 , a mobile communication system  1  includes a mobile terminal device UE_A  10 , an eNB_A  45 , a core network_A  90 , and a PDN_A  5 . 
     Here, the UE_A  10  may be any wirelessly connectable terminal device, and may be a User equipment (UE), a Mobile equipment (ME), or a Mobile Station (MS). 
     The UE_A  10  may be a CIoT terminal. Note that the CIoT terminal is an IoT terminal connectable with a core network A  90 , the IoT terminal includes a mobile phone terminal such as a smartphone, and may be various IT devices such as a personal computer and a sensor device. 
     In other words, in a case that the UE_A  10  is the CIoT terminal, the UE_A  10  may request a connection optimized for the CIoT terminal based on a policy of the UE_A  10  or a request from the network, or may request the known connection. Alternatively, the UE_A  10  may be configured as a terminal device which connects to the core network_A  90  only by a communication procedure optimized in advance for the CIoT terminal at the time when the UE_A  10  is shipped. 
     Here, the core network_A  90  refers to an IP mobile communication network run by a Mobile Operator. 
     For example, the core network_A  90  may be a core network for the mobile operator that runs and manages the mobile communication system  1 , or may be a core network for a virtual mobile operator such as a Mobile Virtual Network Operator (MVNO). Alternatively, the core network_A  90  may be a core network for accommodating the CIoT terminal. 
     Additionally, the eNB_A  45  is a base station constituting a radio access network used by the UE_A  10  to connect to the core network_A  90 . In other words, the UE_A  10  connects to the core network_A  90  using the eNB_A  45 . 
     Additionally, the core network_A  90  is connected to the PDN_A  5 . The PDN_A  5  is a packet data service network which provides a communication service to the UE_A  10 , and may be configured for each service. A communication terminal is connected to the PDN, the UE_A  10  can transmit and/or receive user data to/from the communication terminal located in the PDN_A  5 . 
     Next, an example of a configuration of the core network_A  90  will be described. In the present embodiment, two configuration examples of the core network_A  90  will be described. 
       FIG. 2  illustrates a first example of the configuration of the core network_ 90 . The core network_A  90  in  FIG. 2( a )  includes a Home Subscriber Server (HSS)_A  50 , an Authentication. Authorization, Accounting (AAA)_A  55 , a Policy and Charging Rules Function (PCRF)_A  60 , a Packet Data Network Gateway (PGW)_A  30 , an enhanced Packet Data Gateway (ePDG)_A  65 , a Serving Gateway (SGW)_A  35 , a Mobility Management Entity (MME)_A  40 , and a Serving GPRS Support Node (SGSN)_A  42 . 
     Furthermore, the core network_A  90  is capable of connecting to multiple radio access networks (an LTE AN_A  80 , a WLAN ANb  75 , a WLAN ANa  70 , a UTRAN_A  20 , and a GERAN_A  25 ). 
     Such a radio access network may be configured by connecting to multiple different access networks, or may be configured by connecting to either one of the access networks. Moreover, the UE_A  10  is capable of wirelessly connecting to the radio access network. 
     Moreover, a WLAN Access Network b (WLAN ANb  75 ) that connects to the core network via the ePDG_A  65  and a WLAN Access Network a (WLAN ANa  75 ) that connects to the PGW_A, the PCRF_A  60 , and the AAA_A  55  can be configured as access networks connectable in a WLAN access system. 
     Note that each device has a similar configuration to those of the devices of the related art in a mobile communication system using EPS, and thus detailed descriptions thereof will be omitted. Each device will be described briefly hereinafter. 
     The PGW_A  30  is connected to the PDN_A  5 , the SGW_A  35 , the ePDG_A  65 , the WLAN Ana  70 , the PCRF_A  60 , and the AAA_A  55 , and serves as a relay device configured to transfer user data by functioning as a gateway device between the PDN_A  5  and the core network_A  90 . 
     The SGW_A  35  is connected to the PGW  30 , the MME_A  40 , the LTE AN  80 , the SGSN_A  42 , and the UTRAN_A  20 , and serves as a relay device configured to transfer user data by functioning as a gateway device between the core network_A  90  and the 3GPP access network (the UTRAN_A  20 , the GERAN_A  25 , the LTE AN_A  80 ). 
     The MME_A  40  is connected to the SGW_A  35 , the LTE AN  80 , and the HSS_A  50 , and serves as an access control device configured to perform location information management and access control for the UE_A  10  via the LTE AN  80 . Furthermore, the core network_A  90  may include multiple location management devices. For example, a location management device different from the MME_A  40  may be configured. As with the MME_A  40 , the location management device different from the MME_A  40  may be connected to the SGW_A  35 , the LTE AN  80 , and the HSS_A  50 . 
     Furthermore, in a case that multiple MMEs are included in the core network_A  90 , the MMEs may be connected to each other. With this configuration, the context of the UE_A  10  may be transmitted and/or received between the MMEs. 
     The HSS_A  50  is connected to the MME_A  40  and the AAA_A  55  and serves as a managing node that manages subscriber information. The subscriber information of the HSS_A  50  is referred to during MME_A  40  access control, for example. Moreover, the HSS_A  50  may be connected to the location management device different from the MME_A  40 . 
     The AAA_A  55  is connected to the PGW  30 , the HSS_A  50 , the PCRF_A  60 , and the WLAN ANa  70 , and is configured to perform access control for the UE_A  10  connected via the WLAN ANa  70 . 
     The PCRF_A  60  is connected to the PGW_A  30 , the WLAN ANa  75 , the AAA_A  55 , and the PDN_A  5 , and is configured to perform QoS management on data delivery. For example, the PCRF_A  60  manages QoS of a communication path between the UE_A  10  and the PDN_A  5 . 
     The ePDG_A  65  is connected to the PGW  30  and the WLAN ANb  75  and is configured to deliver user data by functioning as a gateway device between the core network_A  90  and the WLAN ANb  75 . 
     The SGSN_A  42  is connected to the UTRAN_A  20 , the GERAN_A  25 , and the SGW_A  35  and is a control device for location management between a 3G/2G access network (UTRAN/GERAN) and the LTE access network (E-UTRAN). In addition, the SGSN_A  42  has functions of: selecting the PGW and the SGW, managing a time zone of the UE, and selecting the MME at the time of handover to the E-UTRAN. 
     Additionally, as illustrated in  FIG. 2( b ) , each radio access network includes devices to which the UE_A  10  is actually connected (such as a base station device and an access point device), and the like. The devices used in these connections can be thought of as devices adapted to the radio access networks. 
     In the present embodiment, the LTE AN  80  includes the eNB_A  45 . The eNB_A  45  is a radio base station to which the UE_A  10  connects in an LTE access system, and the LTE AN_A  80  may include one or multiple radio base stations. 
     The WLAN ANa  70  includes a WLAN APa  72  and a TWAG_A  74 . The WLAN APa  72  is a radio base station to which the UE_A  10  connects in the WLAN access system trusted by the operator running the core network_A  90 , and the WLAN ANa  70  may include one or multiple radio base stations. The TWAG_A  74  serves as a gateway device between the core network_A  90  and the WLAN ANa  70 . The WLAN APa  72  and the TWAG_A  74  may be configured as a single device. 
     Even in a case that the operator running the core network_A  90  and the operator running the WLAN ANa  70  are different, such a configuration can be implemented through contracts and agreements between the operators. 
     Furthermore, the WLAN ANb  75  is configured to include a WLAN APb  76 . The WLAN APb  76  is a radio base station to which the UE_A  10  connects in the WLAN access system in a case that no trusting relationship is established with the operator running the core network_A  90 , and the WLAN ANb  75  may include one or multiple radio base stations. 
     In this manner, the WLAN ANb  75  is connected to the core network_A  90  via the ePDG_A  65 , which is a device included in the core network_A  90 , serving as a gateway. The ePDG_A  65  has a security function for ensuring security. 
     The UTRAN_A  20  includes a Radio Network Controller (RNC)_A  24  and an eNB (UTRAN)_A  22 . The eNB (UTRAN)_A  22  is a radio base station to which the UE_A  10  connects through a UMTS Terrestrial Radio Access (UTRA), and the UTRAN_A  20  may include one or multiple radio base stations. Furthermore, the RNC_A  24  is a control unit configured to connect the core network_A  90  and the eNB (UTRAN)_A  22 , and the UTRAN_A  20  may include one or multiple RNCs. Moreover, the RNC_A  24  may be connected to one or multiple eNBs (UTRANs)_A  22 . In addition, the RNC_A  24  may be connected to a radio base station (Base Station Subsystem (BSS)_A  26 ) included in the GERAN_A  25 . 
     The GERAN_A  25  includes the BSS_A  26 . The BSS_A  26  is a radio base station to which the UE_A  10  connects through GSM (trade name)/EDGE Radio Access (GERA), and the GERAN_A  25  may be constituted of one or multiple radio base station BSSs. Furthermore, the multiple BSSs may be connected to each other. Moreover, the BSS_A  26  may be connected to the RNC_A  24 . 
     Next, a second example of a configuration of the core network_A  90  will be described. For example, in a case that the UE_A  10  is a CIoT terminal, the core network_A  90  may be configured as illustrated in  FIG. 3( a ) . The core network_A  90  in  FIG. 3( a )  includes a CIoT Serving Gateway Node (C-SGN)_A  95  and the HSS_A  50 . Note that in the same manner as  FIGS. 2A and 2B , in order for the core network_A  90  to provide connectivity to an access network other than LTE, the core network_A  90  may include the AAA_A  55  and/or the PCRF_A  60  and/or the ePDG_A  65  and/or SGSN_A  42 . 
     A C-SGN_A  95  may be a node that has roles of the MME_A  40 , the SGW_A  35 , and the PGW_A  30  in  FIGS. 2A and 2B . The C-SGN_A  95  may be a node for the CIoT terminal. 
     In other words, the C-SGN_A  95  may have a gateway device function between the PDN_A and the core network_A  90 , a gateway device function between the core network_A  90  and a CIOT AN_A  100 , and a location management function of the UE_A  10 . 
     As illustrated in the drawing, the UE_A  10  connects to the core network_A  90  through the radio access network CIOT AN_A  100 . 
       FIG. 3( b )  illustrates the configuration of the CIOT AN_A  100 . As illustrated in the drawing, the CIOT AN_A  100  may be configured including the eNB_A  45 . The eNB_A  45  included in the CIOT AN_A  100  may be the same base station as the eNB_A  45  included in the LTE AN_A  80 . Alternatively, the eNB_A  45  included in the CIOT AN_A  100  may be a base station for CIoT, which is different from the eNB_A  45  included in the LTE AN_A  80 . 
     A first core network and/or a second core network may be constituted by a system optimized for IoT. 
     Note that herein, the UE_A  10  being connected to radio access networks refers to the UE_A  10  being connected to a base station device, an access point, or the like included in each of the radio access networks, and data, signals, and the like being transmitted and/or received also pass through those base station devices, access points, or the like. 
     1.2. Device Configuration 
     The configuration of each device will be described below. 
     1.2.1. eNB Configuration 
     The configuration of the eNB_A  45  will be described below.  FIG. 4( a )  illustrates the device configuration of the eNB_A  45 . As illustrated in the drawing, the eNB_A  45  includes a network connection unit_A  420 , a control unit_A  400 , and a storage unit_A  440 . The network connection unit_A  420  and the storage unit_A  440  are connected to the control unit_A  400  via a bus. 
     The control unit_A  400  is a function unit for controlling the eNB_A  45 . The control unit_A  400  implements various processes by reading out various programs stored in the storage unit_A  440  and executing the programs. 
     The network connection unit_A  420  is a function unit through which the eNB_A  45  connects to the MME_A  40  and/or the SGW_A  35  or the C-SGN_A  95 . Furthermore, the network connection unit_A  420  is a transmission and/or reception function unit through which the eNB_A  45  transmits and/or receives the user data and/or control data to or from the MME_A  40  and/or the SGW_A  35  or the C-SGN_A  95 . 
     The storage unit_A  440  is a function unit for storing programs, data, and the like necessary for each operation of the eNB_A  45 . A storage unit  640  is constituted of, for example, a semiconductor memory, a Hard Disk Drive (HDD), or the like. 
     The storage unit_A  440  may store at least identification information and/or control information and/or a flag and/or a parameter included in a control message transmitted and/or received in an attach procedure and a data transmission procedure, which will be described in 1.3 and 1.4. 
     Furthermore, the eNB_A  45  includes a transmission and/or reception unit transmitting and/or receiving to or from the UE_A  10  the control information and/or the user data. Furthermore, an external antenna is connected to the transmission and/or reception unit. 
     1.2.2. MME Configuration 
     The configuration of the MME_A  40  will be described below.  FIG. 6( a )  illustrates the device configuration of the MME_A  40 . As illustrated in the drawing, the MME_A  40  includes a network connection unit_B  620 , a control unit_B  600 , and a storage unit_B  640 . The network connection unit_B  620  and the storage unit_B  640  are connected to the control unit_B  600  via a bus. 
     The control unit_B  600  is a function unit for controlling the MME_A  40 . The control unit_B  600  implements various processes by reading out and executing various programs stored in the storage unit_B  640 . 
     The network connection unit_B  620  is a function unit through which the MME_A  40  connects to the HSS_A  50  and/or the SGW_A  35 . Furthermore, the network connection unit_B  620  is a transmission and/or reception function unit through which the MME_A  40  transmits and/or receives to or from the HSS_A  50  and/or the SGW_A  35  the user data and/or control data. 
     The storage unit_B  640  is a function unit for storing programs, data, and the like necessary for each operation of the MME_A  40 . The storage unit_B  640  is constituted of, for example, a semiconductor memory, a Hard Disk Drive (HDD), or the like. 
     The storage unit_B  640  may store at least the identification information and/or the control information and/or the flag and/or the parameter included in the control message transmitted and/or received in the attach procedure and the data transmission procedure, which will be described in 1.3 and 1.4. 
     As illustrated in the drawing, the storage unit_B  640  stores an MME context  642 , a security context  648 , and MME emergency configuration data  650 . Note that the MME context includes an MM context and an EPS bearer context. Alternatively, the MME context may include an EMM context and an ESM context. The MM context may be the EMM context, the EPS bearer context may be the ESM context. 
       FIG. 7( b ) ,  FIG. 8( b ) , and  FIG. 9( b )  illustrate information elements of the MME context stored for each UE. As illustrated in the drawings, the MME context stored for each UE includes an IMSI, an IMSI-unauthenticated-indicator, an MSISDN, an MM State, a GUTI, an ME Identity, a Tracking Area List, a TAI of last TAU, an E-UTRAN Cell Global Identity (ECGI), an E-UTRAN Cell Identity Age, a CSG ID, a CSG membership, an Access mode, an Authentication Vector, a UE Radio Access Capability, MS Classmark 2, MS Classmark 3, Supported Codecs, a UE Network Capability, an MS Network Capability, UE Specific DRX Parameters, a Selected NAS Algorithm, an eKSI, a K_ASME, NAS Keys and COUNT, a Selected CN operator ID, a Recovery, an Access Restriction, an ODB for PS parameters, an APN-OI Replacement, an MME IP address for S11, an MME TEID for S11, an S-GW IP address for S11/S4, an S GW TEID for S11/S4, an SGSN IP address for S3, an SGSN TEID for S3, an eNodeB Address in Use for S1-MME, an eNB UE S1AP ID, an MME UE S1AP ID, a Subscribed UE-AMBR, a UE-AMBR, EPS Subscribed Charging Characteristics, a Subscribed RFSP Index, an RFSP Index in Use, a Trace reference, a Trace type, a Trigger ID, an OMC identity, a URRP-MME, CSG Subscription Data, a LIPA Allowed, a Subscribed Periodic RAU/TAU Timer, an MPS CS priority, an MPS EPS priority, a Voice Support Match Indicator, and a Homogenous Support of IMS Voice over PS Sessions. 
     The IMSI is permanent identification information of a user. The IMSI is identical to the IMSI stored in the HSS_A  50 . 
     The IMSI-unauthenticated-indicator is instruction information indicating that this IMSI is not authenticated. 
     MSISDN represents the phone number of UE. The MSISDN is indicated by the storage unit of the HSS_A  50 . 
     The MM State indicates a mobility management state of the MME. This management information indicates an ECM-IDLE state in which a connection between the eNB and the core network is released, an ECM-CONNECTED state in which the connection between the eNB and the core network is not released, or an EMM-DEREGISTERED state in which the MME does not store the location information of the UE. 
     The Globally Unique Temporary Identity (GUTI) is temporary identification information about the UE. The GUTI includes the identification information about the MME (Globally Unique MME Identifier (GUMMEI)) and the identification information about the UE in a specific MME (M-TMSI). 
     The ME Identity is an ID of the UE, and may be the IMEI/IMISV, for example. 
     The Tracking Area List is a list of the tracking area identification information which is assigned to the UE. 
     The TAI of last TAU is the tracking area identification information indicated by a recent tracking area update procedure. 
     The ECGI is cell identification information of the recent UE known by the MME_A  40 . 
     The E-UTRAN Cell Identity Age indicates the elapsed time since the MME acquires the ECGI. 
     The CSG ID is identification information of a Closed Subscriber Group (CSG), in which the UE recently operates, known by the MME. 
     The CSG membership is member information of the CSG of the recent UE known by the MME. The CSG membership indicates whether the UE is the CSG member. 
     The Access mode is an access mode of a cell identified by the ECGI, may be identification information indicating that the ECGI is a hybrid which allows access to both the UEs which is the CSG and is not the CSG 
     The Authentication Vector indicates a temporary Authentication and Key Agreement (AKA) of a specific UE followed by the MME. The Authentication Vector includes a random value RAND used for authentication, an expectation response XRES, a key K_ASME, and a language (token) AUTN authenticated by the network. 
     The UE Radio Access Capability is identification information indicating a radio access capability of the UE. 
     MS Classmark 2 is a classification symbol (Classmark) of a core network of a CS domain of 3G/2G (UTRAN/GERAN). MS Classmark 2 is used in a case that the UE supports a Single Radio Voice Call Continuit (SRVCC) for the GERAN or the UTRAN. 
     MS Classmark 3 is a classification symbol (Classmark) of a radio network of the CS domain of the GERAN. MS Classmark 3 is used in a case that the UE supports the Single Radio Voice Call Continuit (SRVCC) for the GERAN. 
     The Supported Codecs are a code list supported by the CS domain. This list is used in a case that the UE supports SRVCC for the GERAN or the UTRAN. 
     The UE Network Capability includes an algorithm of security supported by the UE and a key derivative function. 
     The MS Network Capability is information including at least one kind of information necessary for the SGSN to the UE having the GERAN and/or UTRAN function. 
     The UE Specific DRX Parameters are parameters used for determining a Discontinuous Reception (DRX) cycle length of the UE. Here, DRX is a function for changing the UE to a low-power-consumption mode in a case that there is no communication in a certain period of time, in order to reduce power consumption of a battery of the UE as much as possible. 
     The Selected NAS Algorithm is a selected security algorithm of a Non-Access Stream (NAS). 
     The eKSI is a key set indicating the K_ASME. The eKSI may indicate whether a security key acquired by a security authentication of the UTRAN or the E-UTRAN is used. 
     The K_ASME is a key for E-UTRAN key hierarchy generated based on a Cipher Key (CK) and an Integrity Key (IK). 
     The NAS Keys and COUNT includes a key K_NASint, a key K_NASenc, and a NAS COUNT parameter. The key K_NASint is a key for encryption between the UE and the MME, the key K_NASenc is a key for security protection between the UE and the MME. Additionally, the NAS COUNT is a count which starts a count in a case that a new key by which security between the UE and the MME is established is configured. 
     The Selected CN operator ID is identification information, which is used for sharing the network among operators, of a selected core network operator. 
     The Recovery is identification information indicating whether the HSS performs database recovery. 
     The Access Restriction is registration information for access restriction. 
     The ODB for PS parameters indicates a state of an operator determined barring (ODB). Here, ODB is an access rule determined by the network operator (operator). 
     The APN-OI Replacement is a domain name substituting for APN when PGW FQDN is constructed in order to execute a DNS resolution. This substitute domain name is applied to all APNs. 
     The MME IP address for S11 is an IP address of the MME used for an interface with the SGW. 
     The MME TEID for S11 is a Tunnel Endpoint Identifier (TEID) used for the interface with the SGW. 
     The S-GW IP address for S11/S4 is an IP address of the SGW used for an interface between the MME and the SGW or between the SGSN and the MME. 
     The S GW TEID for S11/S4 is a TEID of the SGW used for the interface between the MME and the SGW or between the SGSN and the MME. 
     The SGSN IP address for S3 is an IP address of the SGSN used for the interface between the MME and the SGSN. 
     The SGSN TEID for S3 is a TEID of the SGSN used for the interface between the MME and the SGSN. 
     The eNodeB Address in Use for S1-MME is an IP address of the eNB recently used for an interface between the MME and the eNB. 
     The eNB UE S1AP ID is identification information of the UE in the eNB. 
     The MME UE S1AP ID is identification information of the UE in the MME. 
     The Subscribed UE-AMBR indicates the maximum value of a Maximum Bit Rate (MBR) of uplink communication and downlink communication for sharing all Non-Guaranteed Bit Rate (GBR) bearers (non-guaranteed bearers) in accordance with user registration information. 
     The UE-AMBR indicates the maximum value of the MBR of the uplink communication and the downlink communication which are recently used for sharing all the Non-GBR bearers (non-guaranteed bearers). 
     The EPS Subscribed Charging Characteristics indicate a charging performance of the UE. For example, the EPS Subscribed Charging Characteristics may indicate registration information such as normal, prepaid, a flat rate, hot billing, or the like. 
     The Subscribed RFSP Index is an index for a specific RRM configuration in the E-UTRAN acquired from the HSS. 
     The RFSP Index in Use is an index for the specific RRM configuration in the E-UTRAN which is recently used. 
     The Trace reference is identification information for identifying a specific trace record or a record set. 
     The Trace type indicates a type of the trace. For example, the Trace type may indicate a type traced by the HSS and/or a type traced by the MME, the SGW, or the PGW. 
     The Trigger ID is identification information for identifying a constituent element for which the trace starts. 
     The OMC Identity is identification information for identifying the OMC which receives the record of the trace. 
     The URRP-MME is identification information indicating that the HSS requests UE activity notification from the MME. 
     The CSG Subscription Data are a relevant list of a PLMN (VPLMN) CSG ID of a roaming destination and an equivalent PLMN of the roaming destination. The CSG Subscription Data may be associated with an expiration date indicating an expiration date of the CSG ID and an absent expiration date indicating that there is no expiration date for each CSG ID. The CSG ID may be used for a specific PDN connection through LIPA. 
     The LIPA Allowed indicates whether the UE is allowed to use LIPA in this PLMN. The Subscribed Periodic RAU/TAU Timer is a timer of a periodic RAU and/or TAU. 
     The MPS CS priority indicates that the UE is registered in eMLPP or a 1×RTT priority service in the CS domain. 
     The MPS EPS priority is identification information indicating that the UE is registered in MPS in the EPS domain. 
     The Voice Support Match Indicator indicates whether a radio capability of the UE is compatible with the network configuration. For example, the Voice Support Match Indicator indicates whether the SRVCC support by the UE matches the support for voice call by the network. 
     The Homogenous Support of IMS Voice over PS Sessions for MME is instruction information indicating, for each UE, whether an IMS voice call on a PS session is supported. The Homogenous Support of IMS Voice over PS Sessions for MME includes “Supported” in which an IP Multimedia Subsystem (IMS) voice call on a Packet Switched (PS: line switching) session in all the Tracking Areas (TAs) managed by the MME is supported, and “Not Supported” indicating a case where there is no TA in which the IMS voice call on the PS session is supported. Additionally, the MME does not notify the HSS of this instruction information, in a case that the IMS voice call on the PS session is not uniformly supported (the TA in which the support is performed and the TA in which the support is not performed are both present in the MME), and in a case that it is not clear whether it is supported. 
       FIG. 10( c )  illustrates information elements included in the MME context stored in a transmittable and/or receivable state. The transmittable and/or receivable state is described later. At the time of establishing a PDN connection, the MME to be stored in the transmittable and/or receivable state may be stored for each PDN connection. As illustrated in the drawing, the MME context stored in the transmittable and/or receivable state includes an APN in Use, an APN Restriction, an APN Subscribed, a PDN Type, an IP Address, EPS PDN Charging Characteristics, an APN-OI Replacement, SIPTO permissions, a Local Home Network ID, LIPA permissions, a WLAN offloadability, a VPLMN Address Allowed, a PDN GW Address in Use (control information), a PDN GW TEID for S5/S8 (control information), an MS Info Change Reporting Action, a CSG Information Reporting Action, a Presence Reporting Area Action, an EPS subscribed QoS profile, a Subscribed APN-AMBR, an APN-AMBR, a PDN GW GRE Key for uplink traffic (user data), a Default bearer, and a low access priority. 
     The APN in Use indicates APN which is recently used. This APN includes identification information about the APN network and identification information about a default operator. 
     The APN Restriction indicates a restriction on a combination of an APN type to APN associated with this bearer context. In other words, the APN Restriction is information for restricting the number of APNs and the type of APNs which can be established. 
     The APN Subscribed refers to a registration APN received from the HSS. 
     The PDN Type indicates the type of the IP address. The PDN Type indicates IPv4, IPv6, or IPv4v6, for example. 
     The IP Address indicates an IPv4 address or an IPv6 Prefix. Note that the IP address may store both the IPv4 and IPv6 prefixes. 
     The EPS PDN Charging Characteristics indicate a charging performance. The EPS PDN Charging Characteristics may indicate, for example, normal, prepaid, a flat rate, or hot billing. 
     The APN-OI Replacement is a proxy domain name of APN having the same role as that of the APN-OI Replacement, registered for each UE. Note that the APN-OI Replacement has a higher priority than that of the APN-OI Replacement for each UE. 
     The SIPTO permissions indicate permission information to a Selected IP Traffic Offload (SIPTO) of traffic using this APN. Specifically, the SIPTO permissions identify a prohibition of the use of SIPTO, permission of the use of SIPTO in the network excluding the local network, permission of the use of SIPTO in the network including the local network, or permission of the use of SIPTO only in the local network. 
     The Local Home Network ID indicates identification information of a home network to which the base station belongs, in a case that SIPTO (SIPTO@LN) using the local network can be used. 
     The LIPA permissions are identification information indicating whether this PDN can access through LIPA. Specifically, the LIPA permissions may be an LIPA-prohibited which does not allow LIPA, an LIPA-only which allows only LIPA, or an LIPA-conditional which allows LIPA depending on a condition. 
     The WLAN offload ability is identification information indicating whether traffic connected through this APN can perform offload to the wireless LAN by utilizing a cooperative function between the wireless LAN and 3GPP, or maintains the 3GPP connection. The WLAN offload ability may vary for each RAT type. Specifically, different WLAN offload abilities may be present for LTE (E-UTRA) and 3G (UTRA). 
     The VPLMN Address Allowed indicates whether a connection in which the UE uses this APN is allowed to use only an HPLMN domain (IP address) PGW in PLMN (VPLMN) of the roaming destination or allowed to use additionally the PGW in the VPLMN domain. The PDN GW Address in Use (control information) indicates a recent IP address of the PGW. This address is used when a control signal is transmitted. 
     The PDN GW TEID for S5/S8 (control information) is a TEID used for transmission and/or reception of the control information in an interface (S5/S8) between the SGW and the PGW. 
     The MS Info Change Reporting Action is an information element indicating that it is necessary to notify the PGW of user location information being changed. 
     The CSG Information Reporting Action is an information element indicating that it is necessary to notify the PGW of CSG information being changed. 
     The Presence Reporting Area Action indicates necessity of notification of the change as to whether the UE is present in a Presence Reporting Area. This information element separates into identification information of the presence reporting area and an element included in the presence reporting area. 
     The EPS subscribed QoS profile indicates a QoS parameter to a default bearer at a bearer level. 
     The Subscribed APN-AMBR indicates the maximum value of the Maximum Bit Rate (MBR) of the uplink communication and the downlink communication for sharing all the Non-GBR bearers (non-guaranteed bearers) established for this APN in accordance with the user registration information. 
     The APN-AMBR indicates the maximum value of the Maximum Bit Rate (MBR) of the uplink communication and the downlink communication for sharing all the Non-GBR bearers (non-guaranteed bearers) established for this APN, which has been determined by the PGW. 
     The PDN GW GRE Key for uplink traffic (user data) is a Generic Routing Encapsulation (GRE) key for the uplink communication of the user data of the interface between the SGW and the PGW. 
     The Default bearer is EPS bearer identification information for identifying a default bearer in the PDN connection. 
     The low access priority indicates that the UE requests a low access priority, when the PDN connection is opened. 
       FIG. 11( d )  illustrates the MME context stored for each bearer. As illustrated in the drawing, the MME context stored for each bearer includes an EPS Bearer ID, a TI, an S-GW IP address for S1-u, an S-GW TEID for S1u, a PDN GW TEID for S5/S8, a PDN GW IP address for S5/S8, an EPS bearer QoS, and a TFT. 
     The EPS Bearer ID is the only identification information for identifying the EPS bearer for a UE connection via the E-UTRAN. 
     The TI is an abbreviation of a “Transaction Identifier”, and is identification information identifying a bidirectional message flow (Transaction). 
     The S-GW IP address for S1-u is an IP address of the SGW used for an interface between the eNB and the SGW. 
     The S-GW TEID for S1u is a TEID of the SGW used for the interface between the eNB and the SGW. 
     The PDN GW TEID for S5/S8 is a TEID of the PGW for user data transmission in the interface between the SGW and the PGW. 
     The PDN GW IP address for S5/S8 is an IP address of the PGW for user data transmission in the interface between the SGW and the PGW. 
     The EPS bearer QoS includes a QoS Class Identifier (QCI) and an Allocation and Retention Priority (ARP). QCI indicates a class to which the QoS belongs. QoS can be classified in accordance with presence or absence of band control, an allowable delay time, a packet loss rate, or the like. The QCI includes information indicating the priority. ARP is information representing a priority relating to maintaining the bearer. 
     The TFT is an abbreviation of a “Traffic Flow Template”, and indicates all packet filters associated with the EPS bearer. 
     Here, the information elements included in the MME context illustrated in  FIG. 7  to  FIG. 11  are included in either the MM context  644  or the EPS bearer context  646 . For example, the MME context for each bearer illustrated in  FIG. 11( d )  may be stored in the EPS bearer context, and the other information elements may be stored in the MM context. Alternatively, the MME context stored in the transmittable and/or receivable state as illustrated in  FIG. 10( c )  and the MME context for each bearer illustrated in  FIG. 11( d )  may be stored in the EPS bearer context, and the other information elements may be stored in the MM context. 
     As illustrated in  FIG. 6( a ) , the storage unit_B  640  of the MME may store the security context  648 .  FIG. 12( e )  illustrates information elements included in the security context  648 . 
     As illustrated in the drawing, the security context includes an EPS AS security context and an EPS NAS security context. The EPS AS security context is a context relating to security of an access stratum (Access Stream (AS)), the EPS NAS security context is a context relating to security of a non-access stratum (Non-Access Stream (NAS)). 
       FIG. 12( f )  illustrates information elements included in the EPS AS security context. As illustrated in the drawing, the EPS AS security context includes a cryptographic key, a Next Hop parameter (NH), a Next Hop Chaining Counter parameter (NCC), and identifiers of the selected AS level cryptographic algorithms. 
     The cryptographic key is an encryption key in an access stratum. 
     The NH is an information element determined from the K_ASME. The NH is an information element for enabling a forward security. 
     The NCC is an information element associated with the NH. The NCC represents the number of occurrences of handovers in a vertical direction changing the network. 
     The identifiers of the selected AS level cryptographic algorithms are identification information of a selected encryption algorithm. 
       FIG. 12( g )  illustrates information elements included in the EPS NAS security context. As illustrated in the drawing, the EPS NAS security context may include the K_ASME, a UE Security capabilitie, and the NAS COUNT. 
     The K_ASME is a key for E-UTRAN key hierarchy generated based on the keys CK and IK. 
     The UE Security capabilitie is a set of identification information corresponding to a cipher and an algorithm used by the UE. This information includes information for the access stratum and information for the non-access stratum. Furthermore, in a case that the UE supports access to the UTRAN/GERAN, this information includes information for the UTRAN/GERAN. 
     The NAS COUN is a counter indicating the time during which the K_ASME is operating. 
     The security context  648  may be included in the MME context  642 . Additionally, as illustrated in  FIG. 6( a ) , the security context  648  and the MME context  642  may be separately present. 
       FIG. 12( h )  illustrates information elements stored in the MME emergency configuration data  650 . The MME emergency configuration data are information which is used instead of registration information of the UE acquired from the HSS. As illustrated in the drawing, the MME emergency configuration data  650  include an Emergency Access Point Name (em APN), an Emergency QoS profile, an Emergency APN-AMBR, an Emergency PDN GW identity, and a Non-3GPP HO Emergency PDN GW identity. 
     The em APN indicates an access point name used for the PDN connection for emergency. 
     The Emergency QoS profile indicates QoS of the default bearer of em APN at a bearer level. 
     The Emergency APN-AMBR indicates the maximum value of the MBR of the uplink communication and the downlink communication for sharing the Non-GBR bearers (non-guaranteed bearers) established for em APN. This value is determined by the PGW. 
     The Emergency PDN GW identity is identification information of the PGW statically configured to em APN. This identification information may be an FQDN or an IP address. 
     The Non-3GPP HO Emergency PDN GW identity is identification information of the PGW statically configured to em APN, in a case that the PLMN supports a handover to an access network other than 3GPP. This identification information may be an FQDN or an IP address. 
     Furthermore, the MME_A  40  may manage a connection state with respect to the UE while synchronizing with the UE. 
     1.2.3. SGW Configuration 
     Hereinafter, the configuration of the SGW_A  35  will be described.  FIG. 13( a )  illustrates the device configuration of the SGW_A  35 . As illustrated in the drawing, the SGW_A  35  includes a network connection unit_C  1320 , a control unit_C  1300 , and a storage unit_C  1340 . The network connection unit_C  1320  and the storage unit_C  1340  are connected to the control unit_C  1300  via a bus. 
     The control unit_C  1300  is a function unit for controlling the SGW_A  35 . The control unit_C  1300  implements various processes by reading out and executing various programs stored in the storage unit_C  1340 . 
     The network connection unit_C  1320  is a function unit through which the SGW_A  35  connects to the MME_A  40  and/or the PGW_A  30  and/or SGSN_A  42 . Furthermore, the network connection unit_C  1320  is a transmission and/or reception function unit through which the SGW_A  35  transmits and/or receives to or from the MME_A  40  and/or the PGW_A  30  and/or SGSN_A  42  the user data and/or control data. 
     The storage unit_C  1340  is a function unit for storing programs, data, and the like necessary for each operation of the SGW_A  35 . The storage unit_C  1340  is constituted of, for example, a semiconductor memory, a Hard Disk Drive (HDD), or the like. 
     The storage unit_C  1340  may store at least the identification information and/or the control information and/or the flag and/or the parameter included in the control message transmitted and/or received in the attach procedure and the data transmission procedure, which will be described in 1.3 and 1.4. 
     As illustrated in the drawing, the storage unit_C  1340  stores an EPS bearer context  1342 . Note that the EPS bearer context includes an EPS bearer context stored for each UE, an EPS bearer context stored for each PDN, and an EPS bearer context stored for each bearer. 
       FIG. 14( b )  illustrates information elements of the EPS bearer context stored for each UE. As illustrated in  FIG. 14( b ) , the EPS bearer context stored for each UE includes an IMSI, an MSI-unauthenticated-indicator, an ME Identity, an MSISDN, a Selected CN operator id, an MME TEID for S11, an MME IP address for S11, an S-GW TEID for S11/S4, an S-GW IP address for S11/S4, an SGSN IP address for S4, an SGSN TEID for S4, a Trace reference, a Trace type, a Trigger ID, an OMC identity, a Last known Cell Id, and a Last known Cell Id age. 
     The IMSI is permanent identification information of a user. The IMSI is identical to the IMSI in the HSS_A  50 . 
     The IMSI-unauthenticated-indicator is instruction information indicating that this IMSI is not authenticated. 
     The ME Identity is identification information of the UE, and may be the IMEI/IMISV, for example. 
     The MSISDN represents a basic phone number of the UE. The MSISDN is indicated by the storage unit of the HSS_A  50 . 
     The Selected CN operator id is identification information, which is used for sharing the network among operators, of a selected core network operator. 
     The MME TEID for S11 is a TEID of the MME used for the interface between the MME and the SGW. 
     The MME IP address for S11 is an IP address of the MME used for the interface between the MME and the SGW. 
     The S-GW TEID for S11/S4 is a TEID of the SGW used for the interface between the MME and the SGW, or the interface between the SGSN and the SGW. 
     The S-GW IP address for S11/S4 is an IP address of the SGW used for the interface between the MME and the SGW, or the interface between the SGSN and the SGW. 
     The SGSN IP address for S4 is an IP address of the SGSN used for the interface between the SGSN and the SGW. 
     The SGSN TEID for S4 is a TEID of the SGSN used for the interface between the SGSN and the SGW. 
     The Trace reference is identification information for identifying a specific trace record or a record set. 
     The Trace Type indicates a type of the trace. For example, the Trace type may indicate a type traced by the HSS and/or a type traced by the MME, the SGW, or the PGW. 
     The Trigger ID is identification information for identifying a constituent element for which the trace starts. 
     The OMC Identity is identification information for identifying the OMC which receives the record of the trace. 
     The Last known Cell ID is recent location information of the UE notified by the network. 
     The Last known Cell ID age is information indicating the period from the time when the Last known Cell ID is stored to the present. 
     Furthermore, the EPS bearer context includes an EPS bearer context stored in the transmittable and/or receivable state. The transmittable and/or receivable state is described later. At the time of establishing a PDN connection, the EPS bearer context to be stored in the transmittable and/or receivable state may be stored for each PDN connection.  FIG. 15( c )  illustrates the EPS bearer context stored in the transmittable and/or receivable state. As illustrated in the drawing, the EPS bearer context stored in the transmittable and/or receivable state includes an APN in Use, EPS PDN Charging Characteristics, a P-GW Address in Use (control information), a P-GW TEID for S5/S8 (control information), a P-GW Address in Use (user data), a P-GW GRE Key for uplink (user data), an S-GW IP address for S5/S8 (control information), an S-GW TEID for S5/S8 (control information), an S GW Address in Use (user data), a S-GW GRE Key for downlink traffic (user data), and a Default Bearer. 
     The APN in Use indicates APN which is recently used. This APN includes identification information about the APN network and identification information about a default operator. Additionally, this information is information acquired from the MME or the SGSN. 
     The EPS PDN Charging Characteristics indicate a charging performance. The EPS PDN Charging Characteristics may indicate, for example, normal, prepaid, a flat rate, or hot billing. 
     The P-GW Address in Use (control information) is an IP address of the PGW used when the SGW recently transmits the control information. 
     The P-GW TEID for S5/S8 (control information) is a TEID of the PGW used for transmission of the control information in the interface between the SGW and the PGW. 
     The P-GW Address in Use (user data) is an IP address of the PGW used when the SGW recently transmits the user data. 
     The P-GW GRE Key for uplink (user data) is the GRE key for the uplink communication of the user data of the interface between the SGW and the PGW. 
     The S-GW IP address for S5/S8 (control information) is an IP address of the SGW used for the interface of the control information between the SGW and the PGW. 
     The S-GW TEID for S5/S8 (control information) is a TEID of the SGW used for the interface of the control information between the GW and the PGW. 
     The S GW Address in Use (user data) is an IP address of the SGW which is recently used when the SGW transmits the user data. 
     The S-GW GRE Key for downlink traffic (user data) is the GRE key of the uplink communication used for the interface of the user data between the SGW and the PGW. 
     The Default Bearer is identification information for identifying a default bearer in the PDN connection at the time of establishing the PDN connection. 
     Furthermore, the EPS bearer context of the SGW includes the EPS bearer context for each bearer.  FIG. 15( d )  illustrates the EPS bearer context for each bearer. As illustrated in the drawing, the EPS bearer context for each bearer includes an EPS Bearer Id, a TFT, a P-GW Address in Use (user data), a P-GW TEID for S5/S8 (user data), an S-GW IP address for S5/S8 (user data), an S-GW TEID for S5/S8 (user data), an S-GW IP address for S1-u, S12 and S4 (user data), an S-GW TEID for S1-u, S12 and S4 (user data), an eNodeB IP address for S1-u, an eNodeB TEID for S1-u, an RNC IP address for S12, an RNC TEID for S12, an SGSN IP address for S4 (user data), an SGSN TEID for S4 (user data), an EPS Bearer QoS, and a Charging Id. 
     The EPS Bearer Id is the only identification information identifying the EPS bearer for the UE connection via the E-UTRAN. That is, the EPS Bearer Id is identification information for identifying the bearer. 
     The TFT indicates all the packet filters associated with the EPS bearer. 
     The P-GW Address in Use (user data) is an IP address of the PGW which is recently used for transmission of the user data in the interface between the SGW and the PGW. 
     The P-GW TEID for S5/S8 (user data) is a TEID of the PGW for the interface of the user data between the SGW and the PGW. 
     The S-GW IP address for S5/S8 (user data) is an IP address of the SGW for the user data received from the PGW. 
     The S-GW TEID for S5/S8 (user data) is a TEID of the SGW for the interface of the user data between the SGW and the PGW. 
     The S-GW IP address for S1-u, S12 and S4 (user data) is an IP address of the SGW used for the interface between the SGW and the 3GPP access network (the LTE access network or GERAN/UTRAN). 
     The S-GW TEID for S1-u, S12 and S4 (user data) is a TEID of the SGW used for the interface between the SGW and the 3GPP access network (the LTE access network or GERAN/UTRAN). 
     The eNodeB IP address for S1-u is an IP address of the eNB used for transmission between the SGW and the eNB. 
     The eNodeB TEID for S1-u is a TEID of the eNB used for the transmission between the SGW and the eNB. 
     The RNC IP address for S12 is an IP address of the RNC used for the interface between the SGW and the UTRAN. 
     The RNC TEID for S12 is a TEID of the RNC used for the interface between the SGW and the UTRAN. 
     The SGSN IP address for S4 (user data) is an IP address of the SGSN used for transmission of the user data between the SGW and the SGSN. 
     The SGSN TEID for S4 (user data) is a TEID of the SGSN used for the transmission of the user data between the SGW and the SGSN. 
     The EPS Bearer QoS represents the QoS of this bearer, and may include an ARP, a GBR, an MBR, and a QCI. Here, the ARP is information representing the priority relating to maintaining the bearer. Additionally, the Guaranteed Bit Rate (GBR) represents a band guaranteed bit rate, and the Maximum Bit Rate (MBR) represents the maximum bit rate. The QCI can be classified in accordance with presence or absence of band control, an allowable delay time, a packet loss rate, or the like. The QCI includes information indicating the priority. 
     The Charging Id is identification information for recording charging generated in the SGW and the PGW. 
     1.2.4. PGW Configuration 
     Hereinafter, the configuration of the PGW_A  30  will be described.  FIG. 16( a )  illustrates the device configuration of the PGW_A  30 . As illustrated in the drawing, the PGW_A  30  includes a network connection unit_D  1620 , a control unit_D  1600 , and a storage unit_D  1640 . The network connection unit_D  1620  and the storage unit_D  1640  are connected to the control unit_D  1600  via a bus. 
     The control unit_D  1600  is a function unit for controlling the PGW_A  30 . The control unit_D  1600  implements various processes by reading out and executing various programs stored in the storage unit_D  1640 . 
     The network connection unit_D  1620  is a function unit through which the PGW_A  30  is connected to the SGW_A  35  and/or the PCRF_A  60  and/or the ePDG_A  65  and/or the AAA_A  55  and/or the GW_A  74 . The network connection unit_D  1620  is a transmission and/or reception function unit through which the PGW_A  30  transmits and/or receives to or from the SGW_A  35  and/or the PCRF_A  60  and/or the ePDG_A  65  and/or the AAA_A  55  and/or the GW_A  74  the user data and/or control data. 
     The storage unit_D  1640  is a function unit for storing programs, data, and the like necessary for each operation of the PGW_A  30 . The storage unit_D  1640  is constituted of, for example, a semiconductor memory, a Hard Disk Drive (HDD), or the like. 
     The storage unit_D  1640  may store at least the identification information and/or the control information and/or the flag and/or the parameter included in the control message transmitted and/or received in the attach procedure and the data transmission procedure, which will be described later. 
     As illustrated in the drawing, the storage unit_D  1640  stores an EPS bearer context  1642 . Note that the EPS bearer context may be stored in such a manner that an EPS bearer context stored for each UE, an EPS bearer context stored for each APN, an EPS bearer context stored in the transmittable and/or receivable state, and an EPS bearer context stored for each bearer are separately stored. 
       FIG. 17( b )  illustrates information elements included in the EPS bearer context stored for each UE. As illustrated in the drawing, the EPS bearer context stored for each UE includes an IMSI, an IMSI-unauthenticated-indicator, an ME Identity, an MSISDN, a Selected CN operator id, an RAT type, a Trace reference, a Trace type, a Trigger id, and an OMC identity. 
     The IMSI is identification information to be assigned to a user using the UE. 
     The IMSI-unauthenticated-indicator is instruction information indicating that this IMSI is not authenticated. 
     The ME Identity is an ID of the UE, and may be the IMEI/IMISV, for example. 
     The MSISDN represents a basic phone number of the UE. The MSISDN is indicated by the storage unit of the HSS_A  50 . 
     The Selected CN operator ID is identification information, which is used for sharing the network among operators, of a selected core network operator. 
     The RAT type indicates a recent Radio Access Technology (RAT) of the UE. The RAT type may be, for example, the E-UTRA (LTE), the UTRA, or the like. 
     The Trace reference is identification information for identifying a specific trace record or a record set. 
     The Trace type indicates a type of the trace. For example, the Trace type may indicate a type traced by the HSS and/or a type traced by the MME, the SGW, or the PGW. 
     The Trigger ID is identification information for identifying a constituent element for which the trace starts. 
     The OMC Identity is identification information for identifying the OMC which receives the record of the trace. 
     Next,  FIG. 17( c )  illustrates the EPS bearer context stored for each APN. As illustrated in the drawing, the EPS bearer context stored for each APN of the PGW storage unit includes an APN in use and an APN-AMBR. 
     The APN in Use indicates APN which is recently used. This APN includes identification information about the APN network and identification information about a default operator. This information is acquired from the SGW. 
     The APN-AMBR indicates the maximum value of the Maximum Bit Rate (MBR) of the uplink communication and the downlink communication for sharing all the Non-GBR bearers (non-guaranteed bearers) established for this APN. 
       FIG. 18( d )  illustrates the EPS bearer context stored in the transmittable and/or receivable state. The transmittable and/or receivable state is described later. At the time of establishing a PDN connection, the EPS bearer context to be stored in the transmittable and/or receivable state may be stored for each PDN connection. As illustrated in the drawing, the EPS bearer context stored in the transmittable and/or receivable state includes an IP Address, a PDN type, an S-GW Address in Use (control information), an S-GW TEID for S5/S8 (control information), an S-GW Address in Use (user data), an S-GW GRE Key for downlink traffic (user data), a P-GW IP address for S5/S8 (control information), a P-GW TEID for S5/S8 (control information), a P-GW Address in Use (user data), a P-GW GRE Key for uplink traffic (user data), an MS Info Change Reporting support indication, an MS Info Change Reporting Action, a CSG Information Reporting Action, a Presence Reporting Area Action, a BCM, a Default Bearer, and EPS PDN Charging Characteristics. 
     The IP Address indicates an IP address assigned to the UE in the transmittable and/or receivable state. The IP address may be an IPv4 and/or IPv6 prefix. 
     The PDN type indicates the type of the IP address. The PDN type indicates IPv4, IPv6, or IPv4v6, for example. 
     The S-GW Address in Use (control information) is an IP address of the SGW which is recently used for transmission of the control information. 
     The S-GW TEID for S5/S8 (control information) is a TEID of the SGW used for transmission and/or reception of the control information between the SGW and the PGW. 
     The S-GW Address in Use (user data) is an IP address of the SGW which is recently used for transmission of the user data in the interface between the SGW and the PGW. 
     The S-GW GRE Key for downlink traffic (user data) is the GRE key which is assigned to be used in the downlink communication of the user data from the PGW to the SGW at the interface between the SGW and the PGW. 
     The P-GW IP address for S5/S8 (control information) is an IP address of the PGW used for communication of the control information. 
     The P-GW TEID for S5/S8 (control information) is a TEID of the PGW for communication of the control information which uses the interface between the SGW and the PGW. 
     The P-GW Address in Use (user data) is an IP address of the PGW which is recently used for transmission of the user data which uses the interface between the SGW and the PGW. 
     The P-GW GRE Key for uplink traffic (user data) is the GRE key which is assigned for the uplink communication of the user data between the SGW and the PGW, that is, transmission of the user data from the SGW to the PGW. 
     The MS Info Change Reporting support indication indicates that the MME and/or the SGSN supports a notification process of user location information and/or user CSG information. 
     The MS Info Change Reporting Action is information indicating whether the MME and/or the SGSN is requested to transmit a change in the user location information. 
     The CSG Information Reporting Action is information indicating whether the MME and/or the SGSN is requested to transmit a change in the user CSG information. This information is separately indicated (a) for a CSG cell, (b) for a hybrid cell in which a user is a CSG member, (c) for a hybrid cell in which the user is not the CSG member, or for a combination thereof. 
     The Presence Reporting Area Action indicates necessity of notification of the change as to whether the UE is present in a Presence Reporting Area. This information element separates into identification information of the presence reporting area and an element included in the presence reporting area. 
     The Bearer Control Mode (BCM) indicates a control state of a bearer negotiated with respect to the GERAN/UTRAN. 
     The Default Bearer is identification information for identifying a default bearer included in the PDN connection at the time of establishing the PDN connection. 
     The EPS PDN Charging Characteristics are a charging performance. The charging performance may indicate, for example, normal, prepaid, a flat rate, hot billing. 
     Furthermore,  FIG. 18( e )  illustrates the EPS bearer context stored for each EPS bearer. As illustrated in the drawing, the EPS bearer context includes an EPS Bearer Id, a TFT, an S-GW Address in Use (user data), an S-GW TEID for S5/S8 (user data), a P-GW IP address for S5/S8 (user data), a P-GW TEID for S5/S8 (user data), an EPS Bearer QoS, and a Charging Id. 
     The EPS Bearer Id is identification information identifying the access of the UE via the E-UTRAN. 
     The TFT is an abbreviation of a “Traffic Flow Template”, and indicates all packet filters associated with the EPS bearer. 
     The S-GW Address in Use (user data) is an IP address of the SGW which is recently used for transmission of the user data. 
     The S-GW TEID for S5/S8 (user data) is a TEID of the SGW for communication of the user data which uses the interface between the SGW and the PGW. 
     The P-GW IP address for S5/S8 (user data) is an IP address of the PGW for the user data received from the PGW. 
     The P-GW TEID for S5/S8 (user data) is a TEID of the PGW for communication of the user data between the SGW and the PGW. 
     The EPS Bearer QoS indicates the QoS of the bearer, and may include an ARP, a GBR, an MBR, and a QCI. Here, the ARP is information representing the priority relating to maintaining the bearer. Additionally, the Guaranteed Bit Rate (GBR) represents a band guaranteed bit rate, and the Maximum Bit Rate (MBR) represents the maximum bit rate. The QCI can be classified in accordance with presence or absence of band control, an allowable delay time, a packet loss rate, or the like. The QCI includes information indicating the priority. 
     The Charging Id is charging identification information for identifying the record relating to charging generated in the SGW and the PGW. 
     1.2.5. C-SGN Configuration 
     Hereinafter, the device configuration of the C-SGN_A  95  will be described.  FIG. 19( a )  illustrates the device configuration of the C-SGN_A  95 . As illustrated in the drawing, the C-SGN_A  95  includes a network connection unit_E  1920 , a control unit_E  1900 , and a storage unit_E  1940 . The network connection unit_E  1920  and the storage unit_E  1940  are connected to the control unit_E  1900  via a bus. 
     The control unit_E  1900  is a function unit for controlling the C-SGN_A  95 . The control unit_E  1900  implements various processes by reading out and executing various programs stored in the storage unit_E  1940 . 
     The network connection unit_E  1920  is a function unit through which the C-SGN_A  95  connects to the eNB_A  45  and/or the HSS_A  50  and/or the PDN_A  5 . The network connection unit_E  1920  is a transmission and/or reception function unit through which the C-SGN_A  95  transmits and/or receives to or from the eNB_A  45  and/or the HSS_A  50  and/or the PDN_A  5  the user data and/or control data. 
     The storage unit_E  1940  is a function unit for storing programs, data, and the like necessary for each operation of the C-SGN_A  95 . The storage unit_E  1940  is constituted of, for example, a semiconductor memory, a Hard Disk Drive (HDD), or the like. 
     The storage unit_E  1940  may store at least the identification information and/or the control information and/or the flag and/or the parameter included in the control message transmitted and/or received in the attach procedure and the data transmission procedure, which will be described in 1.3 and 1.4. 
     The storage unit_E  1940  stores a context A  1942 , a context B  1944 , a context C  1946 , and a context D  1948  as illustrated in the drawing. 
     The context A  1942  may be the MME context  642  illustrated in  FIG. 6( a ) . Additionally, the context B  1944  may be the security context  648  illustrated in  FIG. 6( a ) . Additionally, the context C  1946  may be the MME emergency configuration data  650  illustrated in  FIG. 6( a ) . 
     Additionally, the context D  1948  may be the EPS bearer context  1342  illustrated in  FIG. 13( a ) . Additionally, the context E  1950  may be the EPS bearer context  1642  illustrated in  FIG. 16( a ) . 
     Note that in a case that the context A  1942  to the context E  1950  include the same information element, such information element may not necessarily be redundantly stored in the storage unit_E  1940 , and may be stored in any context at least. 
     Specifically, for example, the IMSI may be included in each of the context A  1942 , the context D  1948 , and the context E  1950 , or may be stored in any context. 
     1.2.6. UE Configuration 
       FIG. 20( a )  illustrates a device configuration of the UE_A  10 . As illustrated in the drawing, the UE_A  10  includes a transmission and/or reception unit  2020 , a control unit  2000 , and a storage unit  2040 . The transmission and/or reception unit  2020  and the storage unit  2040  are connected to the control unit  2000  via a bus. 
     The control unit  2000  is a function unit for controlling the UE_A  10 . The control unit  2000  implements various processes by reading out and executing various programs stored in the storage unit  2040 . 
     The transmission and/or reception unit  2020  is a function unit through which the UE_A  10  connects to an IP access network via an LTE base station. Furthermore, the external antenna  2010  is connected to the transmission and/or reception unit  2020 . 
     The storage unit  2040  is a function unit for storing programs, data, and the like necessary for each operation of the UE_A  10 . The storage unit  2040  is constituted of, for example, a semiconductor memory, a Hard Disk Drive (HDD), or the like. 
     As illustrated in the drawing, the storage unit  2040  stores a UE context  2042 . Hereinafter, information elements stored in the storage unit  2040  will be described. 
       FIG. 21( b )  illustrates information elements included in the UE context stored for each UE. As illustrated in the drawing, the UE context stored for each UE includes an IMSI, an EMM State, a GUTI, an ME Identity, a Tracking Area List, a last visited TAI, a Selected NAS Algorithm, a Selected AS Algorithm, an eKSI, K_ASME. NAS Keys and COUNT, a TIN. UE Specific DRX Parameters, an Allowed CSG list, and an Operator CSG list. 
     The IMSI is permanent identification information of a subscriber. 
     The EMM State indicates a mobility management state of the UE. For example, the EMM State may be EMM-REGISTERED in which the UE is registered with the network (registered state) or EMM-DEREGISTERD in which the UE is not registered with the network (deregistered state). 
     GUTI is an abbreviation of “Globally Unique Temporary Identity”, and is temporary identification information on the UE. The GUTI includes the identification information about the MME (Globally Unique MME Identifier (GUMMEI)) and the identification information about the UE in a specific MME (M-TMSI). 
     The ME identity is an ID of an ME, and may be the IME/IMISV, for example. 
     The Tracking Area List is a list of the tracking area identification information which is assigned to the UE. 
     The last visited TAI is the tracking area identification information included in the Tracking Area List, and is identification information of the latest tracking area that the UE visits. 
     The Selected NAS Algorithm is a selected security algorithm of the NAS. 
     The Selected AS Algorithm is a selected security algorithm of the AS. 
     The eKSI is a key set indicating the K_ASME. The eKSI may indicate whether a security key acquired by a security authentication of the UTRAN or the E-UTRAN is used. 
     The K_ASME is a key for E-UTRAN key hierarchy generated based on the keys CK and IK. 
     The NAS Keys and COUNT includes the key K_NASint, the key K_NASenc, and the NAS COUNT. The K_NASint is a key for encryption between the UE and the MME, the K_NASenc is a key for safety protection between the UE and the MME. Additionally, the NAS COUNT is a count which starts a count in a case that a new key by which security between the UE and the MME is established is configured. 
     The Temporary Identity used in Next update (TIN) is temporary identification information used in the UE in an attach procedure or a location information update procedure (RAU/TAU). 
     The UE Specific DRX Parameters denote a Discontinuous Reception (DRX) cycle length of the selected UE. 
     The Allowed CSG list is a list of the PLMN associated with a CSG ID of a member to which the allowed UE belongs, under the control of both the user and the operator. 
     The Operator CSG list is a list of the PLMN associated with the CSG ID of a member to which the allowed UE belongs, under the control of only the operator. 
     Next,  FIG. 21( c )  illustrates the UE context stored in the transmittable and/or receivable state. The transmittable and/or receivable state is described later. At the time of establishing a PDN connection, the UE context to be stored in the transmittable and/or receivable state may be stored for each PDN connection. As illustrated in the drawing, the UE context in the transmittable and/or receivable state includes an APN in Use, an APN-AMBR, an Assigned PDN Type, an IP Address, a Default Bearer, and a WLAN offloadability. 
     The APN in Use is APN recently utilized. This APN may include identification information about the network and identification information about a default operator. 
     The APN-AMBR indicates the maximum value of the MBR of the uplink communication and the downlink communication for sharing the Non-GBR bearers (non-guaranteed bearers). The APN-AMBR is established for each APN. 
     The Assigned PDN Type is a type of the PDN assigned from the network. The Assigned PDN Type may be IPv4, IPv6, or IPv4v6, for example. 
     The IP Address is an IP address assigned to the UE, and may be an IPv4 address or an IPv6 prefix. 
     The Default Bearer is EPS bearer identification information for identifying a default bearer in the PDN connection at the time of establishing the PDN connection. 
     The WLAN offloadability is WLAN offload permission information indicating whether offload to the WLAN using an interworking function between the WLAN and the 3GPP is allowed, or the 3GPP access is maintained. 
       FIG. 21( d )  illustrates the UE context for each bearer stored in the storage unit of the UE. As illustrated in the drawing, the UE context for each bearer includes an EPS Bearer ID, a TI, an EPS bearer QoS, and a TFT. 
     The EPS Bearer ID is identification information of the bearer. 
     The TI is an abbreviation of a “Transaction Identifier”, and is identification information identifying a bidirectional message flow (Transaction). 
     The TFT is an abbreviation of a “Traffic Flow Template”, and indicates all packet filters associated with the EPS bearer. 
     1.3. Description of Communication Procedure 
     Next, a communication procedure according to the present embodiment will be described using  FIG. 22 . 
     The communication procedure according to the present embodiment may include an attach procedure (S 2200 ), selection processing of a transmission and/or reception means (S 2202 ), a first transmission and/or reception procedure (S 2204 ), a second transmission and/or reception procedure (S 2206 ), and a third transmission and/or reception procedure (S 2208 ). 
     The first transmission and/or reception procedure (S 2204 ), the second transmission and/or reception procedure (S 2206 ), and/or the third transmission and/or reception procedure (S 2208 ) can be omitted according to conditions. The details of the conditions for each procedure to be performed and processing are described below. 
     Here, before describing the detailed steps of each procedure, in order to avoid redundant descriptions, terminology specific to the present embodiment and primary identification information used in each procedure will be described beforehand. 
     The connectionless communication in the present embodiment may be communication at least performing a process in which the UE_A  10  transmits a Non Access Stratum (NAS) message including data packet to the eNB_A  45  by including in a Radio Rsource Control (RRC) message. Additionally/Alternatively, the connectionless communication may be communication transmitting and/or receiving the data packet between the UE_A  10  and the eNB_A  45  without establishing the RRC connection. Additionally/Alternatively, the connectionless communication may be communication transmitting and/or receiving the data packet during the UE_A  10  being in the idle state. 
     The active mode in the present embodiment may be a mode indicating a state in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  establish the Data Radio Bearer (DRB) and/or the Default Bearer and/or the PDN connection, and are capable of transmitting and/or receiving the user data. 
     Note that the DRB in the present embodiment may be a communication path such as a radio bearer established for transmission and/or reception of the user data. 
     The PDN connection in the present embodiment may be a connection for transmission and/or reception of the user data, the connection being established between the UE_A  10  and the C-SGN_A  95 . 
     The idle mode in the present embodiment may be a mode indicating a state in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  release the resource of the DRB and/or the Default Bearer and/or the PDN connection, and are not capable of transmitting and/or receiving the user data. Note that the idle mode in the present embodiment may be a mode indicating that the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  keep the context for the DRB and/or the Default Bearer and/or the PDN connection. 
     The transmittable and/or receivable state in the present embodiment is a state capable of transmitting and/or receiving the user data between the UE_A  10  and the PDN_A  5 . 
     In more detail, the transmittable and/or receivable state may be a state in which the UE_A  10  and/or the PDN_A  5  and/or the eNB_A  45  and/or the C-SGN_A  95  transmit and/or receive the user data. 
     The transmittable and/or receivable state may include a first mode, a second mode, a third mode, and a fourth mode. 
     The first mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  transmit and/or receive the user data with connectionless. 
     Furthermore, the first mode may be a mode in which the UE_A  10  and/or the eNB_A  45  transmit and/or receive the user data without establishing an RRC connection. 
     Furthermore, the first mode may be a mode in which the UE_A  10  and/or the C-SGN_A  95  transmit and/or receive the user data while being included in the NAS message. 
     Furthermore, the first mode may be a mode in which the UE_A  10  and/or the eNB_A  45  transmit and/or receive the user data while being included in the RRC message. 
     Furthermore, the first mode may be a mode in which the UE_A  10  and/or the eNB_A  45  transmit and/or receive a NAS Packet Data Unit (PDU) while being included in the RRC message. Note that the NAS PDU may be a control message in which the user data is included in the NAS message. 
     Furthermore, the first mode may be a mode in which the UE_A  10  and/or the eNB_A  45  transmit and/or receive the user data by using Signalling Radio Bearer (SRB). 
     Furthermore, the first mode may be a mode in which the UE_A  10  and/or the eNB_A  45  transmit and/or receive the user data by using Control Signalling Radio Bearer (CRB). 
     Each of the SRB and the CRB may be a communication path such as a radio bearer used for transmission and/or reception of a control message. 
     Furthermore, the first mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  transmit and/or receive the user data by using a bearer for transmitting and/or receiving control information. 
     Note that, in a case of the first mode, the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  may transmit and/or receive the user data through the first transmission and/or reception procedure. 
     The second mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  establish a connection to transmit and/or receive the user data. 
     Furthermore, the second mode may be a mode in which the UE_A  10  and/or the eNB_A  45  establish an RRC connection to transmit and/or receive the user data. 
     Furthermore, the second mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  establish a PDN connection to transmit and/or receive the user data. 
     Furthermore, the second mode may be a mode in which the UE_A  10  and/or the eNB_A  45  transmit and/or receive the user data by using Data Radio Bearer (DRB). 
     Furthermore, the second mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  establish a bearer for transmitting and/or receiving the user data to transmit and/or receive the user data. 
     Furthermore, the second mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  establish a default bearer to transmit and/or receive the user data. 
     Furthermore, the second mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  keep the context even after entering the idle mode. 
     Furthermore, the second mode may be a mode in which the UE_A  10  and/or the eNB_A  45  can transmit and/or receive the NAS message while being included in a third message in an RRC. 
     Note that, in a case of the second mode, the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  may transmit and/or receive the user data through the second transmission and/or reception procedure. 
     The third mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  transmit and/or receive the user data with connectionless, or may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  establish a connection to transmit and/or receive the user data. 
     Furthermore, the third mode may be a mode in which the UE_A  10  and/or the eNB_A  45  transmit and/or receive the user data without establishing an RRC connection. 
     Furthermore, the third mode may be a mode in which the UE_A  10  and/or the C-SGN_A  95  transmit and/or receive the user data while being included in the NAS message. 
     Furthermore, the third mode may be a mode in which the UE_A  10  and/or the eNB_A  45  transmit and/or receive the user data while being included in the RRC message. 
     Furthermore, the first mode may be a mode in which the UE_A  10  and/or the eNB_A  45  transmit and/or receive the NAS Packet Data Unit (PDU) while being included in the RRC message. 
     Furthermore, the third mode may be a mode in which the UE_A  10  and/or the eNB_A  45  transmit and/or receive the user data by using Signalling Radio Bearer (SRB). 
     Furthermore, the third mode may be a mode in which the UE_A  10  and/or the eNB_A  45  transmit and/or receive the user data by using Control Signalling Radio Bearer (CRB). 
     Furthermore, the third mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  transmit and/or receive the user data by using a bearer for transmitting and/or receiving control information. 
     Furthermore, the third mode may be a mode in which the UE_A  10  and/or the eNB_A  45  establish an RRC connection to transmit and/or receive the user data. 
     Furthermore, the third mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  establish a PDN connection to transmit and/or receive the user data. 
     Furthermore, the third mode may be a mode in which the UE_A  10  and/or the eNB_A  45  transmit and/or receive the user data by using Data Radio Bearer (DRB). 
     Furthermore, the third mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  establish a bearer for transmitting and/or receiving the user data to transmit and/or receive the user data. 
     Furthermore, the third mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  establish a default bearer to transmit and/or receive the user data. 
     Furthermore, the third mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  keep the context even after entering the idle mode. 
     Furthermore, the third mode may be a mode in which the UE_A  10  and/or the eNB_A  45  can transmit and/or receive the NAS message while being included in the third message in the RRC. 
     Note that, in a case of the third mode, the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  may transmit and/or receive the user data through the first transmission and/or reception procedure and/or the second transmission and/or reception procedure. 
     The fourth mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  establish a connection to transmit and/or receive the user data. 
     Furthermore, the fourth mode may be a mode in which the UE_A  10  and/or the eNB_A  45  establish an RRC connection to transmit and/or receive the user data. 
     Furthermore, the fourth mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  establish a PDN connection to transmit and/or receive the user data. 
     Furthermore, the fourth mode may be a mode in which the UE_A  10  and/or the eNB_A  45  transmit and/or receive the user data by using the DRB. 
     Furthermore, the fourth mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  establish a bearer for transmitting and/or receiving the user data to transmit and/or receive the user data. 
     Furthermore, the fourth mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  establish a default bearer to transmit and/or receive the user data. 
     Furthermore, the fourth mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  establish two or more default bearers to transmit and/or receive the user data. 
     Furthermore, the fourth mode may be a mode in which the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  delete the context after entering the idle mode. 
     Furthermore, the fourth mode may be a mode in which the UE_A  10  and/or the eNB_A  45  cannot transmit and/or receive the NAS message while being included in the third message in the RRC. 
     Note that, in a case of the fourth mode, the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  may transmit and/or receive the user data through the third transmission and/or reception procedure. 
     The first identification information in the present embodiment may be information indicating that the UE_A  10  performing the attach procedure is a Cellular Internet of Things (CIoT) terminal. 
     Additionally/Alternatively, the first identification information may be information indicating a type of attach that indicates an attach by the CIoT terminal. Note that the information indicating the type of attach may be an Attach type. Moreover, an attach type indicating the attach by the CIoT terminal may be a CIoT attach. Additionally/Alternatively, the attach type may be information that indicates an attach type requesting a connection to a system optimized for Internet of Things (IoT). 
     The attach by the CIoT terminal may be an attach for the purpose that the eNB_A  45  selects the C-SGN_A  95  optimized for CIoT and the UE_A  10  connects to the selected C-SGN_A  95 . 
     Additionally/Alternatively, the first identification information may be information indicating that the UE_A  10  requests to connect to the system optimized for CIoT and/or IoT. 
     Additionally/Alternatively, the first identification information may be information indicating that the UE_A  10  includes capability of the CIoT terminal. Note that the information indicating that the UE_A  10  includes the capability of the CIoT terminal may be UE Capability. 
     Additionally/Alternatively, the first identification information may be information indicating that a terminal includes terminal capability for transmitting the user data by using a radio bearer for transmitting and/or receiving a control message. 
     Additionally/Alternatively, the first identification information may be information indicating that the UE_A  10  transmits and/or receives the user data, based on the first transmission and/or reception procedure. 
     Additionally/Alternatively, the first identification information may be information indicating a request to transmit the user data by using the radio bearer for transmitting and/or receiving the control message. In more detail, the first identification information may be information indicating that the UE_A  10  requests to UE_A  10  transmission and/or reception of the user data based on the first transmission and/or reception procedure. 
     Additionally/Alternatively, the first identification information may be information indicating that the UE_A  10  requests to transmit and/or receive the user data, based on the first transmission and/or reception procedure. 
     Additionally/Alternatively, the first identification information may be information indicating that the user data is transmitted and/or received while being included in the NAS message. Additionally/Alternatively, the first identification information may be information indicating a request to transmit and/or receive the user data while being included in the NAS message. 
     Additionally/Alternatively, the first identification information may be information indicating that the user data is transmitted and/or received while being included in the RRC message. 
     Additionally/Alternatively, the first identification information may be information indicating a request to transmit and/or receive the user data while being included in the RRC message. 
     Additionally/Alternatively, the first identification information may be information indicating that the UE_A  10  and/or the eNB_A  45  transmit and/or receive the NAS Packet Data Unit (PDU) while being included in the RRC message. 
     Additionally/Alternatively, the first identification information may be information indicating that the UE_A  10  and/or the eNB_A  45  request to transmit and/or receive the NAS Packet Data Unit (PDU) while being included in the RRC message. 
     Note that the NAS PDU may be a control message in which the user data is included in the NAS message. 
     The second identification information in the present embodiment may be information indicating that an attach using information indicating a type of attach that indicates an attach by the CIoT terminal is allowed. 
     Additionally/Alternatively, the second identification information may be Network Capability Information indicating that network capability is included by which the user data can be transmitted and/or received using a radio bearer for transmitting and/or receiving the control message. In more detail, the second identification information may be information indicating that the C-SGN_A  95  and/or the core network_A  90  include capability of connecting to the CIoT terminal. Note that the information indicating that the C-SGN_A  95  and/or the core network_A  90  include capability of connecting to the CIoT terminal may be NW Capability. 
     Additionally/Alternatively, the second identification information may be information indicating that the C-SGN_A  95  transmits and/or receives the user data, based on the first transmission and/or reception procedure. 
     Additionally/Alternatively, the second identification information may be information indicating that user data is transmitted by using the radio bearer for transmitting and/or receiving the control message is allowed. In more detail, the second identification information may be information indicating that the C-SGN_A  95  allows transmission and/or reception of the user data based on the first transmission and/or reception procedure. 
     Additionally/Alternatively, the second identification information may be information indicating that a connection to the system optimized for IoT is established. 
     The third identification information in the present embodiment may be UE Capability Information indicating that network capability is included by which the user data can be transmitted and/or received by establishing a radio bearer for transmitting and/or receiving the user data. In more detail, the third identification information may be the UE Capability Information indicating that the UE_A  10  includes capability for transmission and/or reception of the user data based on the second transmission and/or reception procedure. 
     Additionally/Alternatively, the third identification information may be information indicating that the UE_A  10  transmits and/or receives the user data, based on the second transmission and/or reception procedure. 
     Additionally/Alternatively, the third identification information may be information indicating a request to transmit and/or receive the user data by establishing the radio bearer for transmitting and/or receiving the user data. In more detail, the third identification information may be information indicating that the UE_A  10  requests to allow transmission and/or reception of the user data based on the second transmission and/or reception procedure. 
     Additionally/Alternatively, the third identification information may be information indicating that the UE_A  10  requests to transmit and/or receive the user data, based on the second transmission and/or reception procedure. 
     Additionally/Alternatively, the third identification information may be information indicating that the terminal capability is included by which the first state transition can be performed, and/or information indicating a request to perform the first state transition. Note that the first state transition may be a state transition by which a state is changed between the active state and the idle state, based on a Resume ID described later. 
     The fourth identification information in the present embodiment may be Network Capability Information indicating that network capability is included by which the user data can be transmitted and/or received by establishing a radio bearer for transmitting and/or receiving the user data. In more detail, the fourth identification information may be the Network Capability Information indicating that the C-SGN_A  95  and/or the core network_A  90  include capability for transmission and/or reception of the user data based on the second transmission and/or reception procedure. 
     Additionally/Alternatively, the fourth identification information may be information indicating that the C-SGN_A  95  transmits and/or receives the user data, based on the second transmission and/or reception procedure. 
     Additionally/Alternatively, the fourth identification information may be information indicating that user data is transmitted and/or received by establishing the radio bearer for transmitting and/or receiving the user data is allowed. In more detail, the fourth identification information may be information indicating that the C-SGN_A  95  allows transmission and/or reception of the user data based on the second transmission and/or reception procedure. 
     Additionally/Alternatively, the fourth identification information may be information indicating that the network capability is included by which the first state transition can be allowed, and/or information indicating that performing the first state transition is allowed. Note that the first state transition may be a state transition by which a state is changed between the active state and the idle state, based on the Resume ID described later. 
     The fifth identification information in the present embodiment may be information indicating that the eNB_A  45  includes capability for transmission and/or reception of the user data based on the second transmission and/or reception procedure. Note that the information indicating that the eNB_A  45  includes capability for transmission and/or reception of the user data based on the second transmission and/or reception procedure may be eNB Capability. 
     Additionally/Alternatively, the fifth identification information may be information indicating that the eNB_A  45  transmits and/or receives the user data, based on the second transmission and/or reception procedure. 
     Additionally/Alternatively, the fifth identification information may be information indicating that the eNB_A  45  allows to transmit and/or receive the user data, based on the second transmission and/or reception procedure. 
     Additionally/Alternatively, the fifth identification information may be information indicating that the eNB_A  45  requests to transmit and/or receive the user data, based on the second transmission and/or reception procedure. 
     The sixth identification information in the present embodiment may be information indicating a type of PDN Address requested by the UE_A  10  to be assigned. The information indicating the type of PDN Address may be a PDN Type. The PDN type may be information indicating an IPv4, may be information indicating an IPv6, and may be information indicating an IPv4v6. 
     Additionally/Alternatively, the sixth identification information may be information indicating that the Data Radio Bearer (DRB) and/or Default Bearer are requested to be established in the attach procedure. 
     The seventh identification information in the present embodiment may be information indicating the PDN Address assigned by the C-SGN_A  95  to the UE_A  10 . The PDN address may be an IPv4 Address, or may be an Interface Identifier (Interface ID) indicated by lower 64 bit information of an IPv6 Address, or may include both the IPv4 address and the interface ID of the IPv6. 
     In more detail, the PDN address may be constituted by an IPv4 address field including the IPv4 address and/or an IPv6 address field including the interface ID of the IPv6. 
     In a case that the PDN address assigned to the UE_A  10  includes an IPv4 address with all elements indicated by zero such as 0.0.0.0, and/or any interface ID of the IPv6, the seventh identification information may be used as information indicating that establishing the Data Radio Bearer (DRB) and/or the Default Bearer in the attach procedure is allowed, in order that the UE_A  10  acquires an IP address. 
     Moreover, in a case that the PDN address assigned to the UE_A  10  is not an address with all elements indicated by zero such as 0.0.0.0 but includes an IPv4 address used by the UE_A  10 , and does not include any interface ID of the IPv6, the seventh identification information may be used as information indicating that the Data Radio Bearer (DRB) and/or the Default Bearer are not established in the attach procedure, in order that the UE_A  10  acquires an IP address. In this case, the seventh identification information may be used as information indicating that acquisition of the IP address is not required after completion of the attach procedure. 
     In a case that all the IPv4 address field of the PDN address includes zero such as 0.0.0.0, the seventh identification information may be used as information indicating or requesting acquisition of the IPv4 address by using DHCP after completion of the attach procedure for the UE_A  10 . 
     In a case that the IPv6 address field of the PDN address includes any interface ID of the IPv6, the seventh identification information may be used as information indicating or requesting acquisition of an IPv6 prefix indicated by upper 64 bit information of an IPv6 address for creating and/or acquiring the IPv6 address by using a stateless address configuration procedure or the like after completion of the attach procedure for the UE_A  10 . 
     The eighth identification information in the present embodiment may be information indicating that the C-SGN_A  95  and/or the core network_A  90  do not include capability for transmission and/or reception of the user data based on the second transmission and/or reception procedure. Note that the information indicating that the C-SGN_A  95  and/or the core network_A  90  do not include capability for transmission and/or reception of the user data based on the second transmission and/or reception procedure may be NW Capability. 
     Additionally/Alternatively, the eighth identification information may be information indicating that the C-SGN_A  95  does not perform transmission and/or reception of the user data based on the second transmission and/or reception procedure. 
     Additionally/Alternatively, the eighth identification information may be information indicating that the C-SGN_A  95  does not allow the transmission and/or reception of the user data based on the second transmission and/or reception procedure to be performed. 
     The ninth identification information in the present embodiment may be information indicating a reason why the C-SGN_A  95  determines not to perform the transmission and/or reception of the user data based on the second transmission and/or reception procedure. 
     Additionally/Alternatively, the eighth identification information may be information indicating a reason why the C-SGN_A  95  determines not to allow the transmission and/or reception of the user data based on the second transmission and/or reception procedure to be performed. 
     Note that the reasons for determination not to perform the transmission and/or reception of the user data based on the second transmission and/or reception procedure, and/or not to allow the transmission and/or reception to be performed may be included in EMM cause. 
     The tenth identification information in the present embodiment may be information indicating that the UE_A  10  performing the detach procedure is the CIoT terminal. 
     Additionally/Alternatively, the tenth identification information may be information indicating a type of detach that indicates a detach by the CIoT terminal. Note that the information indicating the type of detach may be a Detach type. Moreover, a detach type indicating the detach by the CIoT terminal may be a CIoT detach. 
     Additionally/Alternatively, the eleventh identification information may be the detach type requesting that a connection to the system optimized for IoT is released. 
     Additionally/Alternatively, the detach by the CIoT terminal may be a detach for the purpose of releasing the connection of the UE_A  10  connected for the CIoT terminal. 
     Additionally/Alternatively, the tenth identification information may be information indicating that the UE_A  10  releases the connection in which the user data is transmitted and/or received based on the first transmission and/or reception procedure and/or the second transmission and/or reception procedure. 
     Additionally/Alternatively, the tenth identification information may be information indicating that the UE_A  10  requests to release the connection in which the user data is transmitted and/or received based on the first transmission and/or reception procedure and/or the second transmission and/or reception procedure. 
     Additionally/Alternatively, the tenth identification information may be information indicating that the UE_A  10  requests to release the connection to the system optimized for CIoT and/or IoT. 
     The transmittable and/or receivable state of the UE_A  10  performing the detach procedure may be information indicating the first mode and/or the second mode and/or the third mode. 
     The eleventh identification information in the present embodiment may be information indicating that the C-SGN_A  95  performing the detach procedure is connected to the CIoT terminal. 
     Additionally/Alternatively, the eleventh identification information may be information indicating a type of detach that indicates a detach by the CIoT terminal. Note that the information indicating the type of detach may be the Detach type. Moreover, the detach type indicating the detach by the CIoT terminal may be the CIoT detach. 
     Note that the detach by the CIoT terminal may be a detach for the purpose of releasing the connection of the UE_A  10  serving as the CIoT terminal. 
     Additionally/Alternatively, the eleventh identification information may be the detach type requesting that a connection to the system optimized for IoT is released. 
     Additionally/Alternatively, the eleventh identification information may be information indicating that the C-SGN_A  95  releases the connection in which the user data is transmitted and/or received based on the first transmission and/or reception procedure and/or the second transmission and/or reception procedure. 
     Additionally/Alternatively, the eleventh identification information may be information indicating that the C-SGN_A  95  requests to release the connection in which the user data is transmitted and/or received based on the first transmission and/or reception procedure and/or the second transmission and/or reception procedure. 
     The transmittable and/or receivable state of the C-SGN_A  95  performing the detach procedure may be information indicating the first mode and/or the second mode and/or the third mode. 
     The twelfth identification information in the present embodiment may be information indicating a reason why the C-SGN_A  95  determines to perform the detach procedure. 
     For example, a reason for the determination to perform the detach procedure may be information indicating that the UE_A  10 , the C-SGN_A  95 , and/or the eNB_A  45  are prohibited from being in the first mode and/or the second mode and/or the third mode of the transmittable and/or receivable state, based on a change of subscriber information, an operator policy, or the like. In other words, the reason may be information indicating that the UE_A  10 , the C-SGN_A  95 , and/or the eNB_A  45  are prohibited from transmitting and/or receiving the user data through the first transmission and/or reception procedure and/or the second transmission and/or reception procedure, based on a change of subscriber information, an operator policy, or the like. 
     Additionally/Alternatively, the twelfth identification information may be information indicating a reason why the transmission and/or reception of the user data based on the first transmission and/or reception procedure and/or the second transmission and/or reception procedure are prohibited. 
     The reason why the C-SGN_A  95  determines to perform the detach procedure, and/or the reason why the transmission and/or reception of the user data based on the first transmission and/or reception procedure and/or the second transmission and/or reception procedure are prohibited may be included in the EMM cause. 
     Further, in the present embodiment, in a case that two or more kinds of identification information among the first to twelfth identification information are transmitted while being included in the same control message, each kind of identification information may be included and transmitted, or one kind of identification information having meanings indicated by each kind of identification information may be included in the control message. Note that the identification information may be an information element configured as the flag or the parameter. 
     1.3.1. Attach Procedure Example 
     First, an example of an attach procedure will be described. Note that the attach procedure is a procedure which is started on the initiative of the UE_A  10 . In the attach procedure of a normal case, the attach procedure is a procedure for the UE_A  10  to connect to a network. In other words, the attach procedure of the normal case is a procedure for connecting to an access network including the eNB  45 , and is a procedure for further connecting to a core network through the access network. The UE_A  10  establishes a communication path through which the user data is transmitted and/or received with the PDN_A  5  by the attach procedure of the normal case. 
     A trigger when the UE_A  10  starts the attach procedure may be a time when the terminal is switched on, or the like. Additionally, the UE_A  10  may start at an arbitrary timing in a case that the UE_A  10  is not connected to the core network_A  90  regardless of the above. The UE_A  10  may enter the transmittable and/or receivable state, based on connecting to the core network_A  90  network, and/or completion of the attach procedure. 
     Hereinafter, the details of the attach procedure of a normal case are described as a first attach procedure example. 
     In the attach procedure of an abnormal case, the attach procedure is a procedure in which the UE_A  10  has not established a connection to a network at the time of completion of the attach procedure. In other words, the attach procedure of an abnormal case is a procedure in which an attempt to connect to the network by the UE_A  10  fails finally, and a procedure in which the UE_A  10  and/or the C-SGN_A  95  reject that the UE_A  10  connects to the network. The details of an attach procedure example of an abnormal case are described as a second attach procedure example and a third attach procedure example. 
     1.3.1.1. First Attach Procedure Example 
     Hereinafter, an example of the steps of a first attach procedure will be described using  FIG. 23 . 
     First, the UE_A  10  transmits an attach request message to the C-SGN_A  95  (S 2300 ). Note that the UE_A  10  may transmit the attach request message to the eNB_A  45 , and the transmitted attach request message may be transferred to the C-SGN_A  95  via the eNB_A  45 . 
     Additionally, the UE_A  10  may transmit a PDN connectivity request message with the attach request message. Hereinafter, in the description of the present embodiment, the attach request message is described as a message in which the attach request message and the PDN connectivity request message are combined. Furthermore, in the description of the present embodiment, in a case that an expression “identification information is included in the attach request message” is used, the expression means that the identification information is included in the attach request message and/or the PDN connectivity request message. 
     The UE_A  10  may include at least the first identification information and/or the third identification information and/or the sixth identification information in the attach request message. The UE_A  10  may request a transition to the transmittable and/or receivable state by transmitting the attach request message including the first identification information and/or the third identification information. The eNB_A  45  may include the fifth identification information in the attach request message and/or a message for transferring the attach request message. The eNB_A  45  may request a transition to the transmittable and/or receivable state by transmitting the fifth identification information while being included in the attach request message and/or the message for transferring the attach request message. 
     Here, the first identification information and/or the third identification information and/or the sixth identification information may not be transmitted to the C-SGN_A  95  by being included in the attach request message, and may instead be transmitted while being included in a control message different from the attach request in the attach procedure. 
     For example, after transmitting the attach request message, the UE_A  10  may perform a request of EPS Session Management (ESM) information, and a transmission and/or reception procedure of a control message which responds based on the request (S 2302 ). 
     To be more specific, the C-SGN_A  95  transmits an ESM request message to the UE_A  10 . The UE_A  10  receives the ESM request message, and transmits a response message to the C-SGN_A  95 . At this time, the UE_A  10  may transmit the first identification information and/or the third identification information and/or the sixth identification information while being included in the response message. 
     Here, the UE_A  10  may encrypt and transmit the ESM response message. Furthermore, the UE_A  10  may receive information for encrypting the ESM response message from the C-SGN_A  95 . The C-SGN_A  95  may transmit information for encrypting the NAS message to the UE_A  10  with the reception of the attach request message. Note that the NAS message for which the information for encrypting the NAS message is transmitted may be a Security Mode Command message. 
     The C-SGN_A  95  receives the attach request message. Furthermore, the C-SGN_A  95  acquires the first identification information and/or the third identification information and/or the fifth identification information and/or the sixth identification information, based on the reception of the attach request message or the reception of the ESM response message. 
     The C-SGN_A  95  may determine to enter the transmittable and/or receivable state for the UE_A  10 , based on information included in the attach request message, subscriber information, and identification information held by the C-SGN. The transmittable and/or receivable state which is a destination of the transition may be determined, based on the first identification information, and/or the third identification information, and/or the fifth identification information, and/or the sixth identification information, and/or the subscriber information, and/or the second identification information, and/or the fourth identification information. 
     For example, the C-SGN_A  95  approves and determines the transmittable and/or receivable state which is a destination of the transition, based on the presence or absence of the first identification information, and/or the third identification information, and/or the fifth identification information, and/or the second identification information, and/or the fourth identification information. In more detail, the C-SGN_A  95  may approve and determine whether the transmittable and/or receivable state which is a destination of the transition is the first mode, the second mode, the third mode or the fourth mode, based on the first identification information, and/or the third identification information, and/or the fifth identification information, and/or the second identification information, and/or the fourth identification information. Hereinafter, the approval and determination process described above is referred to as a first determination and described. 
     In more detail, the C-SGN_A  95  may enter the transmittable and/or receivable state in the first mode in a case that the attach request includes the first identification information, and the third identification information, and the fifth identification information and that the C-SGN_A  95  holds the second identification information and does not hold the fourth identification information. 
     Moreover, the C-SGN_A  95  may enter the transmittable and/or receivable state in the first mode in a case that the attach request includes the first identification information, and that the attach request does not include the third identification information and/or the fifth identification information, and that the C-SGN_A  95  holds the second identification information. 
     The C-SGN_A  95  may enter the transmittable and/or receivable state in the second mode in a case that the attach request includes the first identification information, and the third identification information, and the fifth identification information and that the C-SGN_A  95  does not hold the second identification information and holds the fourth identification information. 
     The C-SGN_A  95  may enter the transmittable and/or receivable state in the third mode in a case that the attach request includes the first identification information, the third identification information, and the fifth identification information, and that the C-SGN_A  95  holds the second identification information and the fourth identification information. 
     The C-SGN_A  95  may enter the transmittable and/or receivable state in the fourth mode in a case that the attach request does not include the first identification information. 
     The C-SGN_A  95  may enter the transmittable and/or receivable state in the fourth mode in a case that the C-SGN_A  95  does not hold the second identification information and the fourth identification information. 
     Note that the conditions of the transition to the transmittable and/or receivable state in each mode are not limited above. 
     In a case of determining to enter the transmittable and/or receivable state other than the first mode, the C-SGN_A  95  starts an IP-CAN session update procedure (S 2304 ). 
     The IP-CAN session update procedure may be the same as the known procedure, and therefore detailed descriptions thereof will be omitted. 
     The C-SGN_A  95  may assign an IP address to the UE_A  10  as usual. In more detail, the C-SGN_A  95  may assign the IP address of the UE_A  10  and include the IP address in the seventh identification information. 
     The C-SGN_A  95  transmits an attach accept message to the eNB_A  45  with completion of the IP-CAN session update procedure (S 2306 ). 
     Additionally, the C-SGN_A  95  may transmit an Activate default EPS bearer context request message with the attach accept message. Hereinafter, in the description of the present embodiment, the attach accept message is described as a message in which the attach accept message and the Activate default EPS bearer context request message are combined. Furthermore, in the description of the present embodiment, in a case that an expression “identification information is included in the attach accept message” is used, the expression means that the identification information is included in the attach accept message and/or the Activate default EPS bearer context request message. 
     The C-SGN_A  95  may include at least the second identification information and/or the fourth identification information and/or the seventh identification information in the attach accept message. 
     Note that the C-SGN_A  95  may make a connection state for the UE_A  10  the idle mode with the transmission of the attach accept message based on the first determination. In other words, the C-SGN_A  95  may make the connection state for the UE_A  10  the idle mode, based on the transition to the transmittable and/or receivable state. In more detail, the C-SGN_A  95  may make the connection state for the UE_A  10  the idle mode, based on the transmittable and/or receivable state which is a destination of the transition being the first mode. In other words, in a case of transmitting the attach accept message for entering the transmittable and/or receivable state in the second mode, and/or the third mode, and/or the fourth mode, the C-SGN_A  95  may make the connection state for the UE_A  10  the active mode with the transmission of the message. 
     Note that, in a case that the transmittable and/or receivable state which is a destination of the transition is the first mode, the C-SGN_A  95  may establish the DRB, and/or the Default Bearer, and/or the PDN connection for acquisition of the IP address with the UE_A  10  and/or the eNB_A  45 , based on the sixth identification information and/or the seventh identification information. In this case, based on the acquisition of the IP address of the UE_A  10 , the C-SGN_A  95  may release the DRB, and/or the Default Bearer, and/or the PDN connection established with the UE_A  10  and/or the eNB_A  45  for the acquisition of the IP address. 
     The eNB_A  45  receives the attach accept message, and transmits the RRC message including the attach accept message to the UE_A  10  (S 2308 ). Note that the RRC message may be an RRC connection reconfiguration request message. 
     The UE_A  10  receives the RRC message including the attach accept message. Furthermore, in a case that the second identification information and/or the fourth identification information and/or the seventh identification information is included in the attach accept message, the UE_A  10  acquires each piece of identification information. 
     In order to respond to the received RRC message, the UE_A  10  transmits the RRC message to the eNB_A  45  (S 2310 ). The RRC message may be an RRC connection reconfiguration complete message. 
     The eNB_A  45  receives an RRC connection reconfiguration message, and transmits a bearer configuration message to the C-SGN_A  95  based on the reception (S 2312 ). 
     Additionally, the UE_A  10  transmits the RRC message including an attach complete message to the eNB_A  45 , based on the reception of the attach accept message (S 2314 ). 
     Additionally, the UE_A  10  may transmit an Activate default EPS bearer context accept message with the attach complete message. Hereinafter, in the description of the present embodiment, the attach complete message is described as a message in which the attach complete message and the Activate default EPS bearer context accept message are combined. Furthermore, in the description of the present embodiment, in a case that an expression “identification information is included in the attach complete message” is used, the expression means that the identification information is included in the attach complete message and/or the Activate default EPS bearer context accept message. 
     Note that the RRC message to be transmitted while including the attach complete message may be a Direct Transfer message. 
     Whether the Activate default EPS bearer context request message is a message which requires to establish the DRB and/or the Default Bearer may be determined, based on whether the attach accept message includes the second identification information and/or the fourth identification information. 
     In more detail, in a case that the attach accept includes the second identification information and does not include the fourth identification information, the Activate default EPS bearer context request message may be a message not intended to establish the DRB and/or the Default Bearer. 
     In other cases, the Activate default EPS bearer context accept message may be a message intended to establish the DRB and/or the Default Bearer. 
     The UE_A  10  enters the transmittable and/or receivable state, based on the reception of the attach accept message and/or the transmission of the attach complete message. 
     The UE_A  10  may interpret and detect the changed transmittable and/or receivable state, based on the second identification information and/or the fourth identification information and/or the seventh identification information. In more detail, the UE_A  10  may interpret and detect whether the changed transmittable and/or receivable state is the first mode, the second mode, the third mode, or the fourth mode, based on the second identification information, and/or the fourth identification information, and/or the seventh identification information. Hereinafter, the recognition and determination process described above is referred to as a second determination and described. 
     In more detail, the UE_A  10  may enter the transmittable and/or receivable state in the first mode in a case that the attach accept includes the second identification information and does not include the fourth identification information. 
     The UE_A  10  may enter the transmittable and/or receivable state in the second mode in a case that the attach accept does not include the second identification information and includes the fourth identification information. 
     The UE_A  10  may enter the transmittable and/or receivable state in the third mode in a case that the attach accept includes the second identification information and includes the fourth identification information. 
     The UE_A  10  may enter the transmittable and/or receivable state in the fourth mode in a case that the attach accept does not include the second identification information and does not include the fourth identification information. 
     Note that the conditions of the transition to the transmittable and/or receivable state in each mode are not limited above. 
     The UE_A  10  may establish the DRB, and/or the Default Bearer, and/or the PDN connection, based on the reception of the attach accept message and/or the transmission of the attach complete message. 
     Note that in a case that the transmittable and/or receivable state is the first mode, the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  may not establish the DRB and/or the Default Bearer and/or the PDN connection. 
     Even in the case that the transmittable and/or receivable state is the first mode, the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  may establish the DRB and/or the Default Bearer and/or the PDN connection in a case that a procedure for acquiring an IP address of the UE_A  10  is required based on the sixth identification information and/or the seventh identification information. 
     The eNB_ 45  receives the RRC message including the attach complete message, and transmits the attach complete message to the C-SGN_A  95  (S 2316 ). 
     Additionally, the UE_A  10  may transit to the idle mode with the transmission of the attach complete message based on the second determination. 
     Alternatively, the UE_A  10  may receive the RRC message from the eNB_A  45  as the response for the Direct Transfer message including the attach complete message, and may transit to the idle mode with the reception of the response message based on the second determination. 
     As a more detailed example, the UE_A  10  may transmit identification information indicating the transition to the idle mode included in the attach complete message and/or the Direct Transfer message. 
     Furthermore, the eNB_A  45  which receives the Direct Transfer message may transmit the RRC message to be a response to the UE_A  10  based on the received identification information. As described above, the RRC message to be the response may be a message for allowing the transition to the idle mode. 
     In other words, the UE_A  10  can select whether to transit to the idle mode or to maintain the active mode based on the second determination. 
     Alternatively, in a case that the changed transmittable and/or receivable state is the first mode, the UE_A  10  may establish a connection for IP address acquisition with the eNB_A  45  and/or the C-SGN_A  95 , based on the sixth identification information and/or the seventh identification information. Note that the connection may be the DRB, and/or the Default Bearer, and/or the PDN connection. 
     For example, in a case that the changed transmittable and/or receivable state is the first mode, and the seventh identification information indicates that acquisition of the IP address is required after completion of the attach procedure, the UE_A  10  may establish a connection for IP address acquisition with the eNB_A  45  and/or the C-SGN_A  95 . 
     In more detail, in a case that the established transmittable and/or receivable is the first mode, and the seventh identification information includes an IPv4 address with all elements indicated by zero such as 0.0.0.0, and/or any interface ID of the IPv6, the UE_A  10  may establish the connection for IP address acquisition. 
     Note that in a case that the IPv4 address field of the seventh identification information includes an IPv4 address with all elements indicated by zero such as 0.0.0.0, the UE_A  10  may initiate a DHCP procedure to acquire an IPv4 address. 
     Specifically, the UE_A  10  may transmit a message which requests an IPv4 address from a DHCP server, based on the above-described conditions. The UE_A  10  may acquire the IPv4 address by receiving a response message including an IPv4 address assigned to the UE_A  10  from the DHCP server. 
     In a case that the IPv6 address field of the seventh identification information includes any interface ID of the IPv6, the UE_A  10  may acquire the IPv6 prefix indicated by upper 64 bit information of the IPv6 address, and creates or acquires the IPv6 address by using the stateless address configuration procedure. 
     Specifically, the UE_A  10  may transmit a Router Solicitation (RS) message which requests the IPv6 prefix from a router and/or a server, based on the above-described conditions. The UE_A  10  may acquire the IPv6 prefix by receiving a Router Advertisement (RA) message including the assigned IPv6 prefix from the router and/or the server. Furthermore, the UE_A  10  may create or acquire the IPv6 from the acquired IPv6 prefix and the interface ID of the IPv6, based on the reception of the RA message, and/or the reception of the IPv6 prefix included in the RA message. 
     For example, in a case that the changed transmittable and/or receivable state is the first mode, and the sixth identification information indicates an IPv4 address, and the seventh identification includes an IPv4 address used by the UE_A  10 , the IPv4 address not being an IPv4 address with all elements indicated by zero such as 0.0.0.0, and the seventh identification does not include an IPv6 interface ID, the UE_A  10  may not establish the connection for IP address acquisition. 
     Moreover, in a case that the changed transmittable and/or receivable state is the first mode, and the connection for IP address acquisition is established, the UE_A  10  may release the connection established with the eNB_A  45  and/or the C-SGN_A  95 , based on the acquisition of IP address. 
     Hereinafter, a UE_A  10  initiated procedure for releasing the connection between the UE_A  10 , and the eNB_A  45  and/or the C-SGN_A  95  will be described. 
     The UE_A  10  transmits a connection release request message to the eNB_A  45  and/or the C-SGN_A  95 . The connection release request message may be a message for requesting the release of the connection. 
     The eNB_A  45  receives the connection release request message transmitted by the UE_A  10 . The eNB_A  45 , based on the reception of the connection release request message, transmits a connection release request message to the C-SGN_A  95 . 
     The C-SGN_A  95  receives the connection release request message transmitted by the eNB_A  45  and/or the UE_A  10 . The C-SGN_A  95 , based on the reception of the connection release request message, transmits a connection release accept message to the eNB_A  45  and/or the UE_A  10 , Here, the connection release accept message may be a response message to the connection release request message. 
     The C-SGN_A  95 , based on the reception of the connection release request message and/or the transmission of the connection release accept message, releases the context of the C-SGN_A  95  for the connection. The context of the C-SGN_A  95  for the connection may be the context D and/or the context E illustrated in  FIG. 19( a ) . 
     The eNB_A  45  receives the connection release accept message transmitted by the C-SGN_A  95 . The eNB_A  45 , based on the reception of the connection release accept message, transmits a connection release accept message to the UE_A  10 . 
     The eNB_A  45 , based on the reception of the connection release request message, and/or the reception of the connection release accept message, and/or the transmission of the connection release accept message, releases the context of the eNB_A  45  for the connection. 
     The UE_A  10  receives the connection release accept message transmitted by the eNB_A  45  and/or the C-SGN_A  95 . 
     The UE_A  10 , based on the transmission of the connection release request message and/or the reception of the connection release accept message, releases the context of the UE_A  10  for the connection. The context of the UE_A  10  for the connection may be a UE context stored in the transmittable and/or receivable state illustrated in  FIG. 21( c )  and/or a UE context for each bearer illustrated in  FIG. 21( d ) . 
     By the above-described procedures, the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  releases the context for the connection, and the connection between the UE_A  10 , and the eNB_A  45  and/or the C-SGN_A  95  is released. 
     The C-SGN_A  95  receives the attach complete message. 
     The C-SGN_A  95  may transit the connection state for the UE_A  10  to the idle mode based on the reception of the attach complete message. 
     In other words, the C-SGN_A  95  may manage the state of the UE_A  10  as the idle mode based on the transmission of the attach accept message or the reception of the attach complete message. 
     In more detail, in a case that the transmittable and/or receivable state which is the transition destination is the second mode and/or the third mode and/or the fourth mode, the C-SGN_A  95  may manage the state of the UE_A  10  as the idle mode based on the transmission of the attach accept message or the reception of the attach complete message. 
     Note that the UE_A  10  can acquire the UE context illustrated in  FIG. 21  from the core network_A  90  by the attach procedure and store the context. 
     Additionally, the C-SGN_A  95  can acquire each of the contexts A to E illustrated in  FIG. 19( a )  from the UE_A  10 , the eNB_A  45 , or the HSS_A  50  by the attach procedure and store the contexts. 
     By the above-described steps, the UE_A  10  connects to the network, and completes the first attach procedure. Note that the UE_A  10  and/or the C-SGN_A  95  enter the transmittable and/or receivable state with the completion of the first attach procedure. 
     1.3.1.2. Second Attach Procedure Example 
     Hereinafter, an example of the steps of a second attach procedure will be described using  FIG. 24 . 
     Note that the steps from the transmission of an attach request message by the UE_A  10  to the reception of the attach request message by the C-SGN_A  95  may be the same as the steps in the procedure of (A) in  FIG. 23  (S 2400 ). Therefore, description of the steps will be omitted. 
     The C-SGN_A  95  receives the attach request message. Furthermore, the C-SGN_A  95  acquires the first identification information and/or the third identification information and/or the fifth identification information and/or the sixth identification information, based on the reception of the attach request message or the reception of the ESM response message. 
     The C-SGN_A  95  may determine not to enter the transmittable and/or receivable state for the UE_A  10 , based on information included in the attach request message and the subscriber information. The C-SGN_A  95  may determine not to enter the transmittable and/or receivable state, based on the first identification information, and/or the third identification information, and/or the fifth identification information, and/or the sixth identification information, and/or the subscriber information. Hereinafter, the determination process described above is referred to as a thirteenth determination and described. 
     The C-SGN_A  95  transmits an attach reject message to the eNB_A  45 , based on the thirteenth determination (S 2402 ). The C-SGN_A  95  may transmit a PDN connectivity reject message with the attach reject message. Hereinafter, in the description of the present embodiment, the attach reject message is described as a message in which the attach reject message and the PDN connectivity reject message are combined. Furthermore, in the description of the present embodiment, in a case that an expression “identification information is included in the attach reject message” is used, the expression means that the identification information is included in the attach reject message and/or the PDN connectivity reject message. 
     The C-SGN_A  95  may include at least the second identification information and/or the eighth identification information in the attach reject message. 
     The eNB_A  45  receives the attach reject message, and transmits the RRC message including the attach reject message to the UE_A  10  (S 2208 ). Note that the RRC message may be an RRC connection reconfiguration request message. 
     The UE_A  10  receives the RRC message including the attach reject message. The UE_A  10  may detect failure of transition to the transmittable and/or receivable state, based on the reception of the attach reject message, and/or the second identification information and/or the eighth identification information included in the attach reject message. 
     Furthermore, the UE_A  10  may detect that suspend processing cannot be performed in a case of receiving the attach reject message and/or each piece of identification information included in the attach reject message. In other words, the C-SGN_A  95  or the MME_A  40  may detect that suspend processing cannot be performed in a case of transmitting the attach reject message and/or each piece of identification information included in the attach reject message. Note that the suspend processing may be processing in which the UE_A  10  and/or the C-SGN_A  95  and/or the MME_A  40  enter the idle mode to keep the UE context and/or the bearer context in a case that a message for suspending an RRC connection is received from a base station device. 
     By the above-described steps, the UE_A  10  fails to connect to the network, and completes the second attach procedure. 
     The UE_A  10  may perform a new attach procedure, based on the failure of connecting to the network. In more detail, the UE_A  10  may perform the new attach procedure, based on the second identification information and/or the eighth identification information included in the attach reject message. 
     1.3.1.3. Third Attach Procedure Example 
     Hereinafter, an example of the steps of a third attach procedure will be described using  FIG. 25 . 
     Note that the steps from the transmission of an attach request message to the reception of the attach accept message by the UE_A  10  may be the same as the steps in the procedures of (A) and (B) in  FIG. 23  (S 2500 , S 2502 ). Therefore, description of the steps will be omitted. 
     The UE_A  10  receives the RRC message including the attach accept message. Furthermore, in a case that the second identification information and/or the fourth identification information and/or the seventh identification information are included in the attach accept message, the UE_A  10  acquires each piece of identification information. 
     The UE_A  10  may interpret and detect the transmittable and/or receivable state allowed by the C-SGN_A  95 , based on the second identification information and/or the fourth identification information and/or the seventh identification information. In more detail, the UE_A  10  may interpret and detect whether the transmittable and/or receivable state allowed by the C-SGN_A  95  is the first mode, the second mode, the third mode, or the fourth mode, based on the second identification information, and/or the fourth identification information, and/or the seventh identification information. 
     Furthermore, the UE_A  10  may determine to reject the transition to the transmittable and/or receivable state, based on the authentication and detection of the transmittable and/or receivable state allowed by the C-SGN_A  95 . In more detail, in a case that a transmittable and/or receivable state different from a mode intended by the UE_A  10  is allowed by the C-SGN_A  95 , the UE_A  10  may determine to reject the transition to the transmittable and/or receivable state. Hereinafter, the interpretation and determination process described above is referred to as a fourteenth determination and described. 
     In a case that the UE_A  10  determines to reject the transition to the transmittable and/or receivable state by the fourteenth determination, the UE_A  10  transmits an Activate default EPS bearer context reject message to the C-SGN_A  95  via the eNB_A  45  (S 2504 ). 
     The UE_A  10  may include at least the ninth identification information in the Activate default EPS bearer context reject message. The UE_A  10  may reject the transition to the transmittable and/or receivable state by transmitting the attach request message including the ninth identification information. 
     The C-SGN_A  95  receives the Activate default EPS bearer context reject message. The C-SGN_A  95  may detect failure of transition to the transmittable and/or receivable state, based on the received Activate default EPS bearer context reject message, and/or the ninth identification information included in the Activate default EPS bearer context reject message. 
     In more detail, the C-SGN_A  95  may release the context for the UE_A  10  illustrated in  FIG. 19( a ) , based on the received Activate default EPS bearer context reject message, and/or the ninth identification information included in the Activate default EPS bearer context reject message. 
     Furthermore, the UE_A  10  may notify that suspend processing cannot be performed by transmitting the Activate default EPS bearer context reject message or an EPS Session Management (ESM) DUMMY MESSAGE to the C-SGN_A  95  or the MME_A  40 , even in the case of receiving the attach accept message and/or each piece of identification information included in the attach accept message. In other words, the C-SGN_A  95  or the MME_A  40  may detect that suspend processing cannot be performed by receiving the Activate default EPS bearer context reject message or the ESM DUMMY MESSAGE from the UE_A  10 , even in the case of transmitting the attach accept message and/or each piece of identification information included in the attach accept message. 
     By the above-described steps, the UE_A  10  fails to connect to the network, and completes the third attach procedure. 
     The UE_A  10  may perform a new attach procedure, based on the failure of connecting to the network. In more detail, the UE_A  10  may perform the new attach procedure, based on the second identification information and/or the eighth identification information included in the attach reject message. 
     1.3.1.4. Modified Example of Attach Procedure 
     Note that although the attach procedure is described in a case that the core network_A  90  in the attach procedure example described above is a core network configured by including the C-SGN_A  95  described using  FIG. 3( a ) , the core network_A  90  may be a core network configured by including the PGW_A  30 , the SGW_A  35 , the MME_A  40 , or the like as described using  FIG. 2 . 
     In this case, the NAS message such as the attach request message, the attach complete message, or the like transmitted by the UE_A  10  described in this procedure is received by the MME  45 , not by the C-SGN_A  95 . 
     Accordingly, the reception and the processes of the NAS message by the C-SGN_A  95  in the above description can be replaced with those performed by the MME_A  40 . 
     Furthermore, the transmission and the processes of the NAS message such as the attach accept message or the like by the C-SGN_A  95  in the above description can be replaced with those performed by the MME_A  40 . 
     1.3.2. Selection Example of Transmission and/or Reception Means 
     Next, a method of selecting a transmission and/or reception procedure to be used at the time of transmitting the UL user data by the UE_A  10  which entered to the transmittable and/or receivable state will be described. 
     The UE_A  10  selects and determines a procedure to be used to transmit the UL user data among the first transmission and/or reception procedure, the second transmission and/or reception procedure, and the third transmission and/or reception procedure. 
     Here, the first transmission and/or reception procedure may be a procedure for performing transmission and/or reception with connectionless, and the second transmission and/or reception procedure and/or the third transmission and/or reception procedure may be a procedure for establishing a connection to perform transmission and/or reception. The third transmission and/or reception procedure may be a known transmission and/or reception procedure. 
     The UE_A  10  may detect and determine these, based on the transmittable and/or receivable state which is the transition destination. In other words, the UE_A  10  may select and determine these, based on the mode of the transmittable and/or receivable state determined in the second determination. The UE_A  10  may detect and determine these, based on the data size of the transmitted UL user data. 
     In more detail, the UE_A  10  may select and determine to use the first transmission and/or reception procedure, based on the transmittable and/or receivable state being the first mode and/or the third mode. 
     Moreover, the UE_A  10  may select and determine to use the second transmission and/or reception procedure, based on the transmittable and/or receivable state being the second mode and/or the third mode. 
     Furthermore, the UE_A  10  may select and determine to use the third transmission and/or reception procedure, based on the transmittable and/or receivable state being the fourth mode. 
     Furthermore, the UE_A  10  may select and determine to use the second transmission and/or reception procedure and/or the third transmission and/or reception procedure, based on UL user data of large data size to be transmitted. Note that the large data size may indicate that the data size is larger than a threshold. 
     The UE_A  10  may branch into the first transmission and/or reception procedure, the second transmission and/or reception procedure, and the third transmission and/or reception, regardless of these conditions. 
     Hereinafter, selection and determination of a procedure to be used to transmit the UL user data among the first transmission and/or reception procedure, the second transmission and/or reception procedure, and the third transmission and/or reception procedure are referred to as a third determination and described. 
     1.3.3. UL User Data Transmission and/or Reception Procedure Example 
     Next, steps in which the UE_A  10  having established the connection to the network transmits the UL user data will be described. 
     Hereinafter, transmission steps of the UL user data will be described. 
     The UE_A  10  transmits a first message to the eNB_A  45 . The first message is a message for requesting at least transmission timing information and resource assignment information, and the UE_A  10  transmits the first message at least including a randomly selected preamble to the eNB_A  45 . 
     Note that the first message is a control signal of a Physical layer, may be a Random Access Channel (RACH) Preamble message of Message  1 . The first message may be transmitted using a Physical Random Access Channel (PRACH). 
     The eNB_A  45  receives the first message, and transmits a second message to the UE_A  10  as a response to the first message. The second message is transmitted while including at least the transmission timing information and the resource assignment information. To be more specific, the transmission timing information may be a Timing Advance, and the resource assignment information may be a UL Grant. The second message is a control signal in a Media Access Control (MAC) layer, and may be transmitted using a Medium Access Control Random Access Response (MAC RAR). 
     Note that the second message may be a RACH Response message of Message  2 . 
     A communication procedure after the UE_A  10  receives the second message can branch into a first transmission and/or reception procedure example, a second transmission and/or reception procedure example, and a third transmission and/or reception example, which will be described later. 
     The UE_A  10  may branch into the first transmission and/or reception procedure example, and/or the second transmission and/or reception procedure example, and/or the third transmission and/or reception example, based on the third determination. 
     1.3.3.1. Description of First Transmission and/or Reception Procedure Example 
     The first transmission and/or reception procedure example is a procedure in which the UE_A  10  transmits and/or receives the user data without establishing any Data Radio Bearer (DRB). In other words, the first transmission and/or reception procedure example is a procedure for transmitting the user data by using a radio bearer for transmitting and/or receiving a control message. 
     Hereinafter, the first transmission and/or reception procedure example will be described in detail using  FIG. 26 . 
     The UE_A  10  transmits, based on the reception of the second message from the eNB_A  45 , the third message to the eNB_A  45  (S 2600 ). 
     The eNB_A  45  receives the third message transmitted by the UE_A  10 . On the basis of the reception of the third message, the eNB_A  45  transmits a fourth message to the UE_A  10  (S 2602 ). 
     The UE_A  10  transmits the fourth message transmitted by the eNB_A  45 . On the basis of the reception of the fourth message, the UE_A  10  transmits a fifth message to the eNB_A  45  (S 2604 ). 
     The UE_A  10  may transmit the NAS message including the UL user data while being included in the third message and/or the fifth message. Note that the UE_A  10  may encrypt the UL user data or the NAS message including the UL user data to transmit the encrypted UL user data or NAS message. 
     The eNB_A  45  receives the NAS message including the UL user data, based on the reception of the third message and/or the fifth message. 
     On the basis of the reception of the NAS message including the UL user data, the eNB_A  45  may transmit an Initial UE message of an S Application Protocol (S1AP) to the C-SGN_A  95  (S 2606 ). 
     The eNB_A  45  may transmit the S1AP Initial UE message including at least the NAS message in which the UL user data is included. 
     The eNB_A  45  may transmit a complete message to the UE_A  10 , based on the reception of the third message and/or the fifth message, and/or the transmission of the S1AP Initial UE message (S 2608 ). 
     The UE_A  10  receives the complete message transmitted by the eNB_A  45 . 
     The C-SGN_A  95  receives the S1AP Initial UE message transmitted by the eNB_A  45 , and/or the NAS message including the UL user data included in the S1AP Initial UE message. 
     On the basis of the reception of the NAS message including the UL user data included in the S1AP Initial UE message, the C-SGN_A  95  decrypts the received NAS message and/or extracts the user data included in the received NAS message (S 2610 ). Note that the C-SGN_A  95  may decrypt the extracted user data, as needed. 
     The C-SGN_A  95  transmits the user data to the PDN_A  5 , based on the extraction and/or decryption of the user data included in the NAS message (S 2612 ). The C-SGN_A  95  may transmit to the PDN_A  5  after decrypting the user data. 
     By the above-described procedures, the UE_A  10  can transmit the small data packet being the UL user data to the PDN_A  5  without establishing the Data Radio Bearer (DRB). Furthermore, after the completion of the first transmission and/or reception procedure example, the UE_A  10  can enter the idle state, or maintain the idle state. 
     Note that, in a case that the user data to be transmitted and/or received has a large size, the UE_A  10  and/or the C-SGN_A  95  do not transmit and/or receive the user data through the first transmission and/or reception procedure, and may transmit the user data through the second transmission and/or reception procedure. 
     1.3.3.2. Description of Second Transmission and/or Reception Procedure Example 
     The second transmission and/or reception procedure example is a procedure in which the UE_A  10  transmits and/or receives the user data after establishing a DRB. 
     Hereinafter, the second transmission and/or reception procedure example will be described in detail using  FIG. 27 . 
     The UE_A  10  transmits, based on the reception of the second message from the eNB_A  45 , the third message to the eNB_A  45  (S 2700 ). 
     The UE_A  10  may transmit at least the NAS message and/or the Resume ID while being included in the third message. 
     Note that the NAS message may be a message for re-establishing a DRB. 
     The Resume ID may be identification information for identifying the DRB to be re-established. Additionally/Alternatively, the Resume ID may be identification information for identifying the context held by the eNB_A  45 , the context being associated with the DRB to be re-established. Additionally/Alternatively, the Resume ID may be identification information for indicating to make the CIoT terminal in the active state enter the idle state. Additionally/Alternatively, the Resume ID may be identification information for indicating to make the CIoT terminal in the idle state enter the active state. 
     For example, the eNB_A  45  may enter the idle state from the active state by transmitting the Resume ID to the UE_A  10 . Moreover, the UE_A  10  may enter the idle state from the active state by receiving the Resume ID from the eNB_A  45 . 
     The UE_A  10  may enter the active state from the idle state by transmitting the received Resume ID to the eNB_A  45 . Moreover, the eNB_A  45  may enter the active state from the idle state by receiving the Resume ID from the UE_A  10 . 
     Note that the context used in the previous active state can be identified by using the same Resume ID for the Resume ID transmitted and/or received for the transition from the active state to the idle state and the Resume ID transmitted and/or received for the transition from the idle state to the active state. The UE_A  10  and the eNB_A  45  can re-establish a DRB, based on the identified context, or the like, to restore a communication state similar to the last active state. 
     In this way, each of the UE_A  10  and the eNB_A  45  can change its state between the active state and the idle state, based on the Resume ID. The eNB_A  45  receives the third message transmitted by the UE_A  10 . The eNB_A  45  receives the NAS message and/or the Resume ID, based on the reception of the third message. 
     On the basis of the reception of the resume ID included in the third message, the eNB_A  45  re-establishes the DRB identified by the resume ID. 
     The eNB_A  45  transmits a fourth message to the UE_A  10 , based on the reception of the third message and/or the re-establishment of the DRB identified by the Resume ID ( 52702 ). 
     The eNB_A  45  may transmit at least the Resume ID for identifying the re-established DRB while being included in the fourth message. 
     The eNB_A  45  changes the state of the eNB_A  45  into the active mode, based on the reception of the third message, and/or the reception of the NAS message, and/or the re-establishment of the DRB identified by the Resume ID, and/or the transmission of the fourth message. 
     The eNB_A  45  transmits an S1 Application Protocol (S1AP) UE Context Active message to the C-SGN_A  95 , based on the reception of the third message, and/or the reception of the NAS message, and/or the re-establishment of the DRB identified by the Resume ID, and/or the transmission of the fourth message, and/or the state transition of the eNB_A  45  to the active mode (S 2704 ). The eNB_A  45  may transmit the S1AP UE Context Active message including the NAS message. 
     The C-SGN_A  95  receives the S1AP UE Context Active message. On the basis of the reception of the S1AP UE Context Active message, the C-SGN_A  95  changes the state of the C-SGN_A  95  into the active mode. On the basis of the reception of the SAP UE Context Active message, and/or the reception of the NAS message, and/or the state transition of the C-SGN_A  95  to the active mode, the C-SGN_A  95  transmits an S1AP UE context active response message to the eNB_A  45  (S 2706 ). 
     The UE_A  10  receives the fourth message transmitted by the eNB_A  45 . The UE_A  10  changes the state of the UE_A  10  to the active mode, based on the reception of the fourth message and/or the reception of the Resume ID for identifying the re-established DRB included in the fourth message. 
     The UE_A  10  transmits the UL user data to the PDN_A  5  via the eNB_A  45  and/or the C-SGN_A  95 , based on the reception of the fourth message, and/or the reception of the Resume ID for identifying the re-established DRB included in the fourth message, and/or the state transition of the UE_A  10  to the active mode (S 2708 ) (S 2710 ) (S 2712 ). 
     The UE_A  10  continues transmitting the UL user data to the PDN_A  5  via the eNB_A  45  and/or the C-SGN_A  95 , as long as the UL user data to be transmitted exists. Note that presence or absence of the data to be transmitted may be determined from a data residual amount of the buffer which accumulates the UL user data to be transmitted or the like. 
     By the above-described procedures, the UE_A  10  can transmit the UL user data. Furthermore, the UE_A  10  can also receive DownLink (DL) user data by the above-described procedures. Note that the DL user data is transmitted from the PDN_A  5 , and can be received through the C-SGN_A  95  and the eNB_A  45 . 
     The eNB_A  45  transfers the UL user data received from the UE_A  10  to the C-SGN_A  95 . 
     In a case of detecting no reception of the UL user data for a certain period of time, the eNB_A  45  starts the procedure for changing the state(s) of the UE_A  10 , and/or the eNB_A  45 , and/or the C-SGN_A  95  to the idle mode, as illustrated in  FIG. 5 . In other word, the eNB_A  45  does not perform a procedure like the procedure (A) in  FIG. 27 , as long as the eNB_A  45  continues receiving the UL user data. 
     The eNB_A  45  transmits the S1AP UE context release message to the C-SGN_A  95 , based on the detection of no reception of the UL user data for a certain period of time (S 2714 ). 
     The C-SGN_A  95  receives the S1AP UE context release message. On the basis of the reception of the S1AP UE context release message, the C-SGN_A  95  changes the state of the C-SGN_A  95  into the idle mode. On the basis of the reception of the S1AP UE context release message, and/or the state transition of the C-SGN_A  95  to the idle mode, the C-SGN_A  95  transmits an S1AP UE context release response message to the eNB_A  45  (S 2716 ). 
     The eNB_A  45  transmits an RRC Connection Suspend message to the UE_A  10 , based on the transmission of the UE context release message, and/or reception of the UE context release response (S 2718 ). 
     The eNB_A  45  may transmit at least the Resume ID while being included in the RRC Connection Suspend message. 
     Here, the Resume ID may be identification information for identifying the DRB to be released. In more detail, the Resume ID may be identification information for identifying the context held by the UE_A  10  and/or the eNB_A  45 , the context being associated with the DRB to be released. 
     On the basis of the transmission of the RRC Connection Suspend message the Resume ID, the eNB_A  45  releases the DRB identified by the Resume ID. Note that the eNB_A  45  releases the DRB identified by the Resume ID, but may continue to hold the context associated with the released DRB without deleting the context. 
     The eNB_A  45  changes the state of the eNB_A  45  into the idle mode, based on the release of the DRB identified by the Resume ID. 
     The UE_A  10  receives the RRC Connection Suspend message transmitted by the eNB_A  45 . 
     On the basis of the reception of the RRC Connection Suspend message, and/or the reception of the Resume ID included in the RRC Connection Suspend message, the UE_A  10  releases the DRB identified by the Resume ID. Note that the UE_A  10  releases the DRB identified by the Resume ID, but may continue to hold the context associated with the released DRB without deleting the context. 
     The UE_A  10  changes the state of the UE_A  10  into the idle mode, based on the release of the DRB identified by the Resume ID. 
     By the above-described procedures, the UE_A  10  and/or the eNB_A  45  and/or the C-SGN_A  95  can release the DRB and enter the idle mode while holding the context for the UE_A  10  and/or the eNB_A  45 . 
     1.3.3.3. Description of Third Transmission and/or Reception Procedure Example 
     The third transmission and/or reception procedure example is a known transmission and/or reception procedure. 
     The third transmission and/or reception procedure example is a procedure in which the UE_A  10  transmits and/or receives the user data after establishing a DRB. 
     The third transmission and/or reception procedure may be a similar procedure to the second transmission and/or reception procedure. Therefore, detailed description of the procedure will be omitted. 
     In a case of the third procedure, the UE_A  10  may not include the NAS message and/or the Resume ID in the third message, and may transmit the NAS message while being included in the fifth message. 
     Furthermore, the S1AP message(s) transmitted and/or received between the eNB_A  45  and the C-SGN_A  95  is not limited to the UE Context Active message and/or the UE context active response message, and may be any message transmitting and/or receiving the NAS message. 
     Moreover, the UE_A  10  may transmit the UL user data, based on the reception of a response message to the fifth message. 
     1.3.3.4. Modified Example of UL User Data Transmission and/or Reception Procedure 
     Note that although the attach procedure is described in a case that the core network_A  90  in the UL user data transmission and/or reception procedure example described above is a core network configured by including the C-SGN_A  95  described using  FIG. 3( a ) , the core network_A  90  may be a core network configured by including the PGW_A  30 , the SGW_A  35 , the MME_A  40 , or the like as described using  FIG. 2 . 
     In this case, the NAS message transmitted by the UE_A  10  described in this procedure is received by the MME  45 , not by the C-SGN_A  95 . 
     Accordingly, the reception and the processes of the NAS message by the C-SGN_A  95  in the above description can be replaced with those performed by the MME_A  40 . 
     Furthermore, the transmission and the processes of the NAS message by the C-SGN_A  95  in the above description can be replaced with those performed by the MME_A  40 . 
     1.3.4. Detach Procedure Example 
     Next, an example of a detach procedure will be described. Note that the detach procedure is a procedure which is started on the initiative of the UE_A  10  and/or the C-SGN_A  95  and/or the HSS_A  50 , and a procedure for disconnecting the connection to the network. A trigger for starting the detach procedure by the UE_A  10 , and/or the C-SGN_A  95 , and/or the HSS_A  50  may be deterioration of a radio wave state of a 3GPP access system, detection of unstable connectivity, or the like. 
     Additionally, the UE_A  10  may start at an arbitrary timing in a case that the UE_A  10  is connected to the core network_A  90  regardless of the above. The C-SGN_A  95  and/or the HSS_A  50  may start at an arbitrary timing. 
     Note that the details of the detach procedure may be a procedure to be described as the UE initiated detach procedure example, and may be a procedure to be described as the network initiated detach procedure example. 
     1.3.4.1. Description of UE Initiated Detach Procedure Example 
     This procedure is a procedure initiated by the UE_A  10 , in which a connection of the UE_A  10  to the network is disconnected. 
     Hereinafter, an example of the steps of the UE initiated detach procedure will be described using  FIG. 28 . 
     First, the UE_A  10  transmits a detach request message to the C-SGN_A  95  (S 2800 ). Note that the UE_A  10  may transmit the detach request message to the eNB_A  45 , and the transmitted detach request message may be transferred to the C-SGN_A  95  via the eNB  45 . 
     The UE_A  10  may include at least the tenth identification information in the detach request message. The UE_A  10  may request disconnection of the connection to the network, by transmitting the detach request message including the tenth identification information. 
     The C-SGN_A  95  receives the detach request message. Furthermore, the C-SGN_A  95  acquires the tenth identification information, based on the reception of the detach request message. 
     On the basis of the reception of the detach request, and/or the tenth identification information included in the detach request, the C-SGN_A  95  may start the IP-CAN session termination procedure (S 2802 ). The IP-CAN session termination procedure may be the same as the known procedure, and therefore detailed descriptions thereof will be omitted. 
     The C-SGN_A  95  transmits a detach accept message to the UE_A  10  via the eNB_A  45  with completion of the IP-CAN session termination procedure (S 2804 ). Note that the detach accept message may be a response message to the detach request message. 
     On the basis of the reception of the detach request, and/or completion of the IP-CAN session termination procedure, and/or transmission of the detach accept, and/or the tenth identification information included in the detach request, the C-SGN_A  95  may disconnect the connection to the network. In more detail, the C-SGN_A  95  may release the context used for the connection to the network, and thus disconnect the connection to the network. 
     Note that the context used for the connection to the network to be released may be the context A, and/or the context B, and/or the context C, and/or the context D, and/or the context E which are illustrated in  FIG. 19 . 
     The UE_A  10  receives the detach accept transmitted by the C-SGN_A  95 . 
     The UE_A  10  may disconnect the connection to the network, based on the reception of the detach accept. In more detail, the UE_A  10  may release the context used for the connection to the network, and thus disconnect the connection to the network. 
     Note that the context used for the connection to the network to be released may be the UE context stored in the transmittable and/or receivable state illustrated in  FIG. 21( c ) , and/or the UE context for each bearer illustrated in  FIG. 21( d ) . 
     Furthermore, the UE_A  10  may perform a signalling connection release procedure with the eNB_A  45 , based on the reception of the detach accept. In other words, the eNB_A  45  may perform the signalling connection release procedure with the UE_A  10 , based on the transmission of the detach accept. 
     By the above-described steps, the UE_A  10  and/or the C-SGN_A  95  disconnect the connection to the network and complete the detach procedure. 
     Note that although the detach procedure is described in a case that the core network_A  90  in the detach procedure example described above is a core network configured by including the C-SGN_A  95  described using  FIG. 3( a ) , the core network_A  90  may be a core network configured by including the PGW_A  30 , the SGW_A  35 , the MME_A  40 , or the like as described using  FIG. 2 . 
     In this case, the NAS message such as the detach request message or the like transmitted by the UE_A  10  described in this procedure is received by the MME  45 , not by the C-SGN_A  95 . 
     Accordingly, the reception and the processes of the NAS message by the C-SGN_A  95  in the above description can be replaced with those performed by the MME_A  40 . 
     Furthermore, the transmission and the processes of the NAS message such as the detach accept message or the like by the C-SGN_A  95  in the above description can be replaced with those performed by the MME_A  40 . 
     1.3.4.2. Description of Network Initiated Detach Procedure Example 
     This procedure is a procedure initiated by the C-SGN_A  95  and/or the HSS_A  50 , in which a connection of the UE_A  10  to the network is disconnected. 
     Hereinafter, an example of the steps of the network initiated detach procedure will be described using  FIG. 5 . 
     First, the HSS_A  50  transmits a Cancel Location message to the C-SGN_A  95  (S 2900 ). The HSS_A  50  may include the twelfth identification information in the Cancel Location message. 
     The C-SGN_A  95  receives the Cancel Location message. The C-SGN_A  95  transmits a detach request message to the UE_A  10  via the eNB_A  45 , based on the Cancel Location message and/or the twelfth identification information included in the Cancel Location message (S 2902 ). 
     Moreover, the C-SGN_A  95  may transmit the detach request message to the UE_A  10  via the eNB_A  45  at an arbitrary timing, not based on the reception of the Cancel Location message. 
     The C-SGN_A  95  may include at least the eleventh identification information and/or the twelfth identification information in the detach request message. The C-SGN_A  95  may request disconnection of the connection to the network, by transmitting the detach request message including the eleventh identification information and/or the twelfth identification information. 
     The C-SGN_A  95  transmits a Cancel Location ACK message to the HSS_A  50 , based on the reception of the Cancel Location message, and/or the reception of the eleventh identification information included in the Cancel Location message, and/or the transmission of the detach request message (S 2904 ). Note that the Cancel Location ACK message may be a response message to the Cancel Location message. 
     The C-SGN_A  95  may start the IP-CAN session termination procedure, based on the reception of the Cancel Location message, and/or the reception of the eleventh identification information included in the Cancel Location message, and/or the transmission of the detach request message, and/or the transmission of the Cancel Location ACK message (S 2906 ). The IP-CAN session termination procedure may be the same as the known procedure, and therefore detailed descriptions thereof will be omitted. 
     The UE_A  10  receives the detach request message transmitted by the C-SGN_A  95 . Furthermore, the UE_A  10  acquires the eleventh identification information and/or the twelfth identification information, based on the reception of the detach request message. 
     The UE_A  10  transmits a detach accept message to the C-SGN_A  95  via the eNB_A  45 , based on the reception of the detach request message, and/or the eleventh identification information and/or the twelfth identification information included in the detach request message (S 2908 ). Note that the detach accept message may be a response message to the detach request message. 
     On the basis of the reception of the detach request, and/or transmission of the detach accept, and/or the eleventh identification information and/or the twelfth identification information included in the detach request, the UE_A  10  may disconnect the connection to the network. In more detail, the UE_A  10  may release the context used for the connection to the network, and thus disconnect the connection to the network. 
     Note that the context used for the connection to the network to be released may be the UE context stored in the transmittable and/or receivable state illustrated in  FIG. 21( c ) , and/or the UE context for each bearer illustrated in  FIG. 21( d ) . 
     The C-SGN_A  95  receives the detach accept transmitted by the UE_A  10 . 
     The C-SGN_A  95  receives the detach accept. Additionally/Alternatively, the C-SGN_A  95  may disconnect the connection to the network, based on the completion of the IP-CAN session termination procedure, and/or the transmission of the Cancel Location ACK message. In more detail, the C-SGN_A  95  may release the context used for the connection to the network, and thus disconnect the connection to the network. 
     Note that the context used for the connection to the network to be released may be the context A, and/or the context B, and/or the context C. and/or the context D, and/or the context E which are illustrated in  FIG. 19 . 
     Furthermore, the UE_A  10  may perform the signalling connection release procedure with the eNB_A  45 , based on the transmission of the detach accept. In other words, the eNB_A  45  may perform the signalling connection release procedure with the UE_A  10 , based on the reception of the detach accept. 
     By the above-described steps, the UE_A  10  and/or the C-SGN_A  95  disconnect the connection to the network and complete the detach procedure. 
     1.3.4.3. Modified Example of Detach Procedure 
     Note that although the detach procedure is described in a case that the core network_A  90  in the detach procedure example described above is a core network configured by including the C-SGN_A  95  described using  FIG. 3( a ) , the core network_A  90  may be a core network configured by including the PGW_A  30 , the SGW_A  35 , the MME_A  40 , or the like as described using  FIG. 2 . 
     In this case, the NAS message such as the detach request message or the like transmitted by the UE_A  10  described in this procedure is received by the MME  45 , not by the C-SGN_A  95 . 
     Accordingly, the reception and the processes of the NAS message by the C-SGN_A  95  in the above description can be replaced with those performed by the MME_A  40 . 
     Furthermore, the transmission and the processes of the NAS message such as the detach accept message or the like by the C-SGN_A  95  in the above description can be replaced with those performed by the MME_A  40 . 
     2. MODIFIED EXAMPLE 
     A program running on each of the mobile station device and base station device according to the present invention is a program that controls CPU and the like (a program for causing a computer to operate) in such a manner as to realize the functions according to the above-described embodiment of the present invention. The information handled by these devices is temporarily held in a RAM at the time of processing, and is then stored in various types of ROMs. HDDs, and the like, and read out by the CPU as necessary to be edited and written. Here, a semiconductor medium (ROM, a non-volatile memory card, or the like, for example), an optical recording medium (DVD, MO, MD, CD, BD, or the like, for example), a magnetic recording medium (magnetic tape, a flexible disk, or the like, for example), and the like can be given as examples of recording media for storing the programs. In addition to realizing the functions of the above-described embodiments by executing loaded programs, the functions of the present invention are realized by the programs running cooperatively with an operating system, other application programs, or the like in accordance with instructions included in those programs. 
     In a case of delivering these programs to market, the programs can be stored in a portable recording medium, or transferred to a server computer connected via a network such as the Internet. In this case, the storage device serving as the server computer is also included in the present invention. Furthermore, some or all portions of each of the mobile station device and the base station device according to the above-described embodiment may be realized as LSI that is a typical integrated circuit. The functional blocks of each of the mobile station device and the base station device may be individually realized as a chip, or some or all of the functional blocks may be integrated into a chip. The circuit integration technique is not limited to LSI, and the integrated circuits for the functional blocks may be realized as dedicated circuits or a multi-purpose processor. Furthermore, in a case where with advances in semiconductor technology, a circuit integration technology with which an LSI is replaced appears, it is also possible to use an integrated circuit based on the technology. Additionally, although, for the above-described embodiments, LTE and WLAN (IEEE 802.11a/b/n, for example) have been described as examples of the radio access network, the connections may be made with WiMAX instead of WLAN. The embodiments of the invention have been described in detail thus far with reference to the drawings, but the specific configuration is not limited to the embodiments. Other designs and the like that do not depart from the essential spirit of the invention also fall within the scope of the patent claims. 
     REFERENCE SIGNS LIST 
     
         
           1  Communication system 
           5  PDN_A 
           10  UE_A 
           20  UTRAN_A 
           22  eNB (UTRAN)_A 
           24  RNC_A 
           25  GERAN_A 
           26  BSS_A 
           30  PGW_A 
           35  SGW_A 
           40  MME_A 
           45  eNB_A 
           50  HSS_A 
           55  AAA_A 
           60  PCRF_A 
           65  ePDG_A 
           70  WLAN ANa 
           72  WLAN APa 
           74  TWAG_A 
           75  WLAN ANb 
           76  WLAN APb 
           80  LTE AN_A 
           90  Core network_A 
           95  C-SGN_A 
           100  CIOT AN_A