TW201542009A - User equipment and base station - Google Patents

Abstract

User equipment which performs communication using cell groups under different base stations comprises: a reception unit which receives, from the base station of a maser cell group, a parameter for a security key for communicating with a secondary cell group; a security key setting unit which sets the security key for communicating with the secondary cell group; a security key setting completion notification unit which notifies the base station of the secondary cell group of the completion of setting of the security key by a random access procedure; and a transmission/reception start determination unit which starts the transmission of uplink data and reception of downlink data using the set security key when the random access procedure is completed.

Description

Mobile station and base station Field of invention

The present invention relates to a mobile station, a base station, and a transmission/reception start determination method.

Background of the invention

In the LTE (Long Term Evolution) system, it is divided into an access layer (AS: Access-Stratum) security function and a non-access layer (NAS: Non-Access-Stratum) security function for the base station. The security association parameter (the parameter for setting the security key) between the access layer (eNB: evolved Node B) and the mobile station (UE: User Equipment) is managed by the eNB.

Figure 1 shows the order in which the security keys are generated in the LTE system. In the LTE system, a security key is generated in accordance with AKA (Authentication and Key Agreement).

First, the key K is shared between the USIM (Universal Subscriber Identity Module) and the AuC (Authentication Center). Each time the mutual authentication between the network and the user is performed, a key CK (Cipher Key) and an IK (Integrity Key) used for encryption and integrity are generated. When the UE connects to the network, the UE and the HSS (Home Subscriber Service) generate K _ASME from the keys CK and IK. UE and MME: NAS between the (Mobility Management Entity MME): key K _NASenc and safety (Network Attached Storage additional access network) encryption Agreement (the encrypt) with a guarantee of the key K _NASint It is produced from K _ASME . When the UE is connected to the network, the MME generates the key K _eNB and delivers it to the eNB. At the time of handover, the RRC connection configuration reset (Connection Reconfiguration) ends, and the K _{eNB is} regenerated. From the K _eNB, a key K _ingint and K _{RRCenc for} encryption and completeness guarantee for U-Plane data encryption and _UP and RRC (Radio Resource Control) are _generated . In addition, there is also the case when the key _KUPint for the complete guarantee of the U-Plane data is not generated (refer to 3GPP TS 33.401 V11.7.0 (2013-06)).

Summary of invention

As described above, in the LTE system, the security function of the access layer is implemented between the UE and the eNB.

On the other hand, the dual connectivity of the UE using the resources of two or more eNBs for data communication is reviewed. Dual Connectivity is a form of carrier aggregation (CA) that uses high cell populations under different eNBs to manage high throughput (CA), also known as inter eNB CA.

In Dual Connectivity, the respective cell populations of different eNBs are assumed to use different frequencies. In Dual Connectivity, it is a master cell group (MSG: Master Cell Group) that is highly reliable in securing connectivity with the UE, and a secondary cell group in which UEs are additionally connected to the main cell group ( SCG: Secondary Cell Group). The base station corresponding to the MCG is called MeNB (Master eNB: Master Base Station), and the base station corresponding to SCG is called SeNB (Secondary eNB: Sub Base Station).

Figure 2 shows a conceptual diagram of Dual Connectivity. The connection form of the Dual Connectivity shown in FIG. 2 is called an architecture option 1, and the PDCP (Packet Data Convergence Protocol) entity exists in different eNBs. Therefore, the security association parameters are also managed by the respective eNBs, the security key for communication with the MCG (hereinafter referred to as the MeNB security key K _eNB ), and the security key for communication with the SCG (hereinafter referred to as the SeNB security key SK _eNB). )different.

On the other hand, the security association parameter is notified to the UE by the RRC message, and the SeNB cannot send the RRC message to the UE. For this reason, the SeNB cannot grasp the opportunity for the UE to set the security key. When the UE and the SeNB do not use the security key at a predetermined opportunity, there is a possibility that the UE cannot correctly receive the data sent by the SeNB, and the SeNB can correctly receive the data sent by the UE, and the S-GW cannot be correctly transmitted. (Serving Gateway: service gateway) and the possibility of discarding it exists.

The purpose of the present invention is to grasp the security key in the double connection. The setting opportunity is used to appropriately judge the start of transmission/reception.

The mobile station according to one aspect of the present invention is a mobile station that uses cell group communication under different base stations, and includes: a receiving unit that receives parameters of a security key for communicating with the secondary cell group from a base station of the primary cell group; The security key setting unit sets a security key for communicating with the secondary cell group; the security key setting completion notification unit notifies the base station of the secondary cell group by completing the setting of the security key by using a random access procedure; The transmission/reception start determining unit starts the transmission of the uplink data and the reception of the downlink data using the set security key when the random access procedure is completed.

Moreover, the mobile station according to one aspect of the present invention is a mobile station that uses cell group communication under different base stations, and includes: a receiving unit that receives a security key for communicating with the secondary cell group from a base station of the primary cell group. a parameter; a security key setting unit that sets a security key for communicating with the secondary cell group; and a transmission/reception start determination unit that starts the uplink using the set security key when the security key setting is completed Transmission of road data and reception of downlink data.

Moreover, the base station of one aspect of the present invention is a base station in a wireless system in which a mobile station uses cell group communication under different base stations, and includes: The receiving unit receives a security key for communicating the mobile station with the secondary cell group from the base station of the primary cell group; the security key setting unit sets a security key for communicating the mobile station with the secondary cell group; And transmitting, via the base station of the main cell group, parameters of the security key for communicating the mobile station and the secondary cell group to the mobile station; and transmitting/receiving the start determining unit, and grasping the mobile station by the random access procedure After the setting of the security key is completed, the transmission of the downlink data and the reception of the uplink data are started using the set security key.

Moreover, the base station of one aspect of the present invention is a base station in a wireless system in which a mobile station uses cell group communication under different base stations, and includes: a receiving unit that receives the mobile station from the base station of the main cell group. The security key for the secondary cell group communication; the security key setting unit sets the security key for communicating the mobile station with the secondary cell group; and the transmitting unit, via the base station of the primary cell group, is used to make the mobile station and the secondary The parameters of the security key of the cell group communication are sent to the mobile station; and the transmission/reception start determining unit receives the security key from the base station of the main cell group with respect to the communication between the mobile station and the secondary cell group. When the parameter setting request is responded, the completion of the setting of the security key in the mobile station is completed, and the transmission of the downlink data is started using the set security key, and when the setting of the security key in the base station is completed. The uplink data is received using the set security key.

Moreover, the mobile station of one form of the present invention uses different base stations. The mobile station of the cell group communication includes: a receiving unit that receives information of a new bearing added to the secondary cell group from the base station of the main cell group, or a base station that is unloaded to the secondary cell group and is in the main cell group The information carried in the communication; the security key setting completion notification unit, the base station that notifies the completion of the bearer setting by the random access procedure; and the transmission/reception start judgment unit when the random access procedure is completed For the addition of a new bearer or an offloaded bearer, transmission of uplink data and reception of downlink data are started.

Moreover, the mobile station according to one aspect of the present invention is a mobile station that uses cell group communication under different base stations, and includes: a receiving unit that receives information of a new bearer added to the secondary cell group from a base station of the main cell group, or Is the information of the bearer that is unloaded to the secondary cell group and is in the base station communication of the primary cell group; and the transmission/reception start determining unit starts the uplink with respect to the additional new bearer or the unloaded bearer when the bearer setting is completed. Transmission of link data and reception of downlink data.

Further, the base station according to one aspect of the present invention is a base station in a wireless system in which a mobile station uses a cell group communication under the jurisdiction of a different base station, and includes a receiving unit that receives an additional sub-cell group from a base station of the main cell group. The information of the new bearer, or the information of the bearer that is unloaded to the secondary cell group and in the base station communication of the main cell group; the transmitting unit, via the base station of the main cell group, adds the newly carried information or the unloaded bearer. Information sent to the mobile station; and The transmission/reception start determining unit grasps the completion of the setting of the bearer in the mobile station by the random access procedure, and starts the transmission of the downlink data and the reception of the uplink data with respect to the additional new bearer or the unloaded bearer.

Further, the base station according to one aspect of the present invention is a base station in a wireless system in which a mobile station uses a cell group communication under the jurisdiction of a different base station, and includes a receiving unit that receives an additional sub-cell group from a base station of the main cell group. The information of the new bearer, or the information of the bearer that is unloaded to the secondary cell group and in the base station communication of the main cell group; the transmitting unit, via the base station of the main cell group, adds the newly carried information or the unloaded bearer. The information is transmitted to the mobile station; and the transmission/reception start determination unit grasps the action when receiving a response request from the base station of the main cell group with respect to the information including the information of the added new bearer or the information of the unloaded bearer. The completion of the setting of the security key in Taichung, the transmission of the downlink data with respect to the additional new bearer or the unloaded bearer, and the new bearer or the unloading when the bearer setting in the base station is completed Bearer, start receiving uplink data.

According to the present invention, the timing of setting the security key is grasped in the double connection, whereby the start of transmission/reception can be appropriately determined.

10‧‧‧ mobile station

101‧‧‧DL signal receiving department

103‧‧‧UL signal transmission department

105‧‧‧Signal Measurement Department

107‧‧‧Security Key Setting Department

109‧‧‧Security Key Setting Completion Notification Department

111‧‧‧UL Data Buffer Department

113‧‧‧Send/receive start judgment unit

20‧‧‧Base Station

201‧‧‧UL signal receiving department

203‧‧‧DL signal transmission department

205‧‧‧Cell Addition Change Department

207‧‧‧Security Key Setting Department

209‧‧‧DL Data Buffer Section

211‧‧‧Send/receive start judgment unit

213‧‧‧Based between the base station

FIG. 1 is a diagram showing a generation order of security keys in an LTE system.

Figure 2 is a conceptual diagram of Dual Connectivity.

3 is a sequence diagram of a procedure for setting a security key for a SeNB in Dual Connectivity.

Figure 4 is a diagram showing the stratification of a key in Dual Connectivity.

Fig. 5 is a view showing the configuration of a mobile station according to an embodiment of the present invention.

Fig. 6 is a view showing the configuration of a base station according to an embodiment of the present invention.

Fig. 7 is a sequence diagram showing a security key setting program and a transmission start determination program in the embodiment of the present invention (a form in which cells of the SeNB are added for the first time).

Fig. 8 is a sequence diagram showing a security key setting program and a transmission start determination program in the embodiment of the present invention (a form in which a new bearer is added to the set SeNB).

Fig. 9 is a sequence diagram showing the security key setting procedure and the transmission start determination routine of the embodiment of the present invention (in the form of the set SeNB, the bearer in the MeNB offload communication).

Detailed description of the preferred embodiment

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In the embodiment of the present invention, a description will be given of a form in which a mobile station manages cell group communication under different base stations in carrier aggregation (CA). Such a connection form of CA is referred to as Dual Connectivity.

In the example shown in FIG. 2, the mobile station (UE) is a dual-wire (Dual Connectivity) using cell group communication of different frequencies under the jurisdiction of two base stations (MeNB and SeNB). In Dual Connectivity, A primary cell population (MCG) that guarantees connectivity to the UE and is highly reliable is set, and a secondary cell population (SCG) of the UE that is connected to the primary cell population is additionally set. The base station corresponding to the MCG is called MeNB, and the base station corresponding to SCG is called SeNB. In addition, in FIG. 2, two cell groups are set, but three or more cell groups may be set.

In Dual Connectivity, the bearer set to the UE from the S-GW and via the MeNB and the bearer set to the UE from the S-GW and via the SeNB may be different. This is produced in the following form.

(1) a mode in which a bearer (offload) in communication is offloaded under MeNB when a cell of the SeNB is added for the first time; (2) adding a new bearer to the set SeNB; (3) A form in which the set SeNB is offloaded in the communication under the MeNB.

In such a configuration, there are different eNBs in the PDCP (Packet Data Convergence Protocol) entity, and thus the security association parameters are also managed by the respective eNBs.

On the other hand, the security association parameter is notified to the UE by the RRC message, and the SeNB cannot send the RRC message to the UE, so the security association parameter of the SeNB is notified to the UE by the RRC message from the MeNB. Specific examples will be described below.

FIG. 3 is a procedure for setting a security key for a SeNB in Dual Connectivity.

The UE periodically reports the measurement result (Meas Report) of the signal quality to the MeNB (S11). When it is determined that the cell of the SeNB has to be added based on the measurement result, the MeNB generates the SeNB secure key SK _eNB (S13). Specifically, as shown in FIG. 4, the SeNB uses the secure key SK _{eNB to} be generated via SK _eNB =KDF (K _eNB , SCC). However, the KDF is a hash function for generating a security key, the K _eNB is a security key for the MeNB, and the SCC (SK _eNB chaining count) is a counter for defining the security key SK _eNB . As the SeNB generates the secure key SK _eNB , the SK _eNB generates a key for U-Plane data encryption, that is, SK _UPenc . In addition, when the key for integrity guarantee of U-Plane data is _{KUPint, it} cannot be generated.

Then, in order to indicate the addition of the cells of the SeNB, the MeNB transmits an SCG additional indication containing the information of the generated security key SK _eNB to the SeNB (S15). The SeNB adds an instruction to the SCG to set the SeNB security key SK _eNB and transmits a parameter SCG additional request (sition request) including the security key notified to the UE to the MeNB (S17). At this point of time, the SeNB becomes able to use the SeNB secure key SK _eNB (S19).

The MeNB transmits a parameter of the security key included in the SCG attach request to the UE via the RRC connection configuration (Connection Reconfiguration) (S21). The UE sets the SeNB security key SK _eNB and sends the RRC connection configuration complete connection (Connection Reconfiguration Complete) to the MeNB (S23) in order to report that the setting of the RRC connection configuration reset has been completed. At this point, the UE becomes able to use the SeNB secure key SK _eNB (S25). Then, the MeNB transmits an SCG additional response to the SeNB as a response to the SCG attach request (S27).

As described above, SeNB set SeNB set SeNB with the timing of the safety key SK _eNB with different security keys SK _eNB and UE's timing, SeNB SeNB not directly control the timing of a UE Security Key is set. Furthermore, the SeNB cannot grasp whether the UE has normally set the SeNB security key. Therefore, for the above three cases, the timing of the security key setting is specified as follows.

In the case of (1), when the random access procedure performed by the UE is completed, both the UE and the SeNB start communication of the uplink data and the downlink data.

In the case of (2) and (3), when the random access procedure by the UE is completed, both the UE and the SeNB start transmission/reception of uplink data and downlink data. Alternatively, when the setting of the security key by the UE is completed, the UE starts the transmission of the uplink data and the reception of the downlink data. When the path with the core network is established, the SeNB starts the downlink. The transmission of the data starts the reception of the uplink data when the setting of the security key by the SeNB is completed.

In addition, the random access procedure performed by the UE may also be implemented by an instruction from the network side (for example, MeNB). For example, the RRC connection configuration reset specifies the RA procedure initiate IE or the designated RACH preamble IE, thereby facilitating the implementation of the random access procedure for the UE. .

The configuration and operation of a specific UE and eNB will be described below.

<Composition of the mobile station>

Fig. 5 is a view showing the configuration of a mobile station according to an embodiment of the present invention. The mobile station 10 includes a DL (Downlink) signal receiving unit 101, an UL (Uplink) signal transmitting unit 103, a signal measuring unit 105, a security key setting unit 107, and a security key setting completion notification unit. 109. The UL data buffer unit 111 and the transmission/reception start determining unit 113.

The DL signal receiving unit 101 receives the downlink signals from the MeNB and the SeNB. Regarding the setting of the security key for the SeNB, the DL signal receiving unit 101 receives the parameter for setting the security key for the SeNB by the MeNB. This parameter may also be included in the RRC connection sent by the MeNB when the cell of the SeNB is added, when a new bearer is added to the set SeNB, or when the bearer is offloaded to the SeNB in the MeNB communication. Configuration reset. Further, the DL signal receiving unit 101 receives a signal for measuring the signal quality with respect to the base station. Further, the DL signal receiving unit 101 receives a message about the random access procedure from the SeNB.

The UL signal transmitting unit 103 transmits an uplink signal to the MeNB and the SeNB. Regarding the setting of the SeNB security key, the UL signal transmitting unit 103 transmits the response to the RRC connection configuration reset, that is, the RRC connection configuration reset completion to the MeNB. Further, the UL signal transmitting unit 103 transmits the measurement result of the signal quality to the MeNB. Further, the UL signal transmitting unit 103 transmits a message regarding the random access sequence to the SeNB.

The signal measuring unit 105 measures the reception quality with respect to the eNB based on the predetermined signal received by the DL signal receiving unit 101. The measured reception quality is used to select the eNB to which the mobile station is to be connected.

The security key setting unit 107 is used by the DL signal receiving unit 101. The received SeNB sets the security key for the SeNB using the parameters of the security key.

The security key setting completion notification unit 109 notifies the SeNB of the completion of the setting of the security key in the security key setting unit 107. The secure key setting completion notification unit 109 may also notify the SeNB of the completion of the setting of the security key by the random access procedure. Alternatively, the notification of the completion of the expressive completion by the notification unit 109 by the security key setting completion is not used, and the existing message may be treated as the completion of the setting of the security key.

The UL data buffer unit 111 stores the uplink data until the transmission of the uplink data of the set SeNB security key is started, with the setting of the security key by the SeNB.

The transmission/reception start determining unit 113 determines the transmission of the uplink data using the set SeNB security key and the start of the transfer of the downlink data. When the random access procedure is used in the security key setting completion notification unit 109, the transmission/reception start determining unit 113 starts the transmission of the uplink data using the set SeNB security key when the random access procedure is completed. And reception of downlink data. When the notification of the completion of the explicit completion by the security key setting completion notification unit 109 is not used, the transmission/reception start determination unit 113 uses the set SeNB security when the SeNB security key setting is completed. The key starts the transmission of uplink data and the reception of downlink data.

When a security key for the SeNB is generated for each SCG, a new bearer is added to the set SeNB, and the same SeNB security key is used. Similarly, when the SeNB security key is generated per SCG, the set SeNB will be offloaded in the MeNB communication, and the same SeNB security key is also used. In this case, the setting of the security key is not required for the SeNB, but the transmission/reception start determining unit 113 determines the transmission of the uplink data and the downlink data as described above with respect to the added or unloaded bearer. The beginning of the reception. In other words, the transmission/reception start determining unit 113 starts transmission of uplink data and reception of downlink data with respect to the added or unloaded bearer when the random access procedure is completed. When the random access procedure is not used, the transmission/reception start determining unit 113 starts the transmission of the uplink data and the reception of the downlink data with respect to the added or unloaded bearer when the setting of the bearer is completed.

<Composition of base station>

Fig. 6 is a view showing the configuration of a base station according to an embodiment of the present invention. 6 is a base station 20 corresponding to the SeNB. The base station 20 includes a UL signal receiving unit 201, a DL signal transmitting unit 203, a cell addition changing unit 205, a security key setting unit 207, and a DL data buffer unit 209. The transmission/reception start determination unit 211 and the base station inter-layer surface 213.

The UL signal receiving unit 201 receives the signal from the UE. The SeNB cannot receive and receive the RRC message, and therefore the UL signal receiving unit 201 only needs to receive the data signal from the UE. Regarding the setting of the security key for the SeNB, the UL signal receiving unit 201 receives a message regarding the random access procedure from the UE.

The DL signal transmitting unit 203 transmits a signal to the UE. The SeNB cannot send and receive RRC messages, and therefore the DL signal transmitting unit 203 mainly transmits the data signal to the UE. Regarding the setting of the security key for the SeNB, the DL signal transmitting unit 203 transmits a message regarding the random access procedure to the UE.

The cell addition changing unit 205 performs an instruction from the MeNB. Addition or change of cells of SeNB. When the cells of the SeNB are to be added for the first time, the cell addition changing unit 205 adds the cells of the SeNB based on the instruction from the MeNB (SCG addition indication). In addition, the SCG additional indication includes information about the SeNB security key generated by the MeNB. When the set SeNB newly adds a bearer, or when the set SeNB unloads the bearer in the MeNB communication, the cell addition changing unit 205 sets the bearer in the SeNB according to an instruction from the MeNB (SCG modification indication). . In addition, the SCG modification indication also includes information about the SeNB security key generated by the MeNB. In addition, the SeNB security key may not be generated for each bearer, and may also be generated per SCG.

The security key setting unit 207 sets the security key for the SeNB by using the information of the security key included in the instruction (SCG addition/modification indication) of the MeNB received by the cell addition changing unit 205.

The DL data buffer unit 209 stores the downlink data until the start of the transmission of the downlink data of the SeNB security key using the setting of the security key by the SeNB.

The transmission/reception start determining unit 211 determines the start of transmission of the downlink data and the reception of the uplink data using the set SeNB security key. The transmission/reception start determining unit 211 starts the transmission of the downlink data and the reception of the uplink data using the set SeNB security key when the SeNB security key is set and the random access procedure is completed. When the setting of the security key is completed and the random access program cannot be used, the transmission/reception start judging section 211 is more specific when the channel with the core network is established. In the case where the MeNB receives a response (SCG attach/modify response) with respect to the SCG setting request (SCG attach/modify request) including the parameter for setting the SeNB security key, the set SeNB security is used. The key starts the transmission of the downlink data. When the setting of the security key is completed by the SeNB, the received SeNB security key is used to start the reception of the uplink data.

The base station interface 213 is an interface for communicating with the MeNB. Regarding the setting of the security key for the SeNB, when the base station inter-facing device 213 first adds the cell of the SeNB, when the set SeNB newly adds the bearer, or when the set SeNB is to be unloaded in the MeNB communication, The SCG attach/modify indication containing the information of the SeNB security key is received from the MeNB. In addition, the base station interface 213 will notify the UE of the security key in response to the SCG attach/modify instruction. The SCG attach/modify request for the parameter is sent to the MeNB. Further, the base station inter-layer face 213 receives a SCG addition/modification response (SCG addition/modification response) in response to the SCG attach/modify request from the MeNB.

When the SeNB security key is generated per SCG, the same SeNB security key is used even if a new bearer is added to the set SeNB. Similarly, when the SeNB security key is generated per SCG, the same SeNB security key is used even if the set SeNB will perform bearer offloading in the MeNB communication. In this case, although the setting of the security key is not required by the SeNB, the transmission/reception start determining unit 211 determines the transmission of the downlink data and the reception of the uplink data with respect to the added or unloaded bearer as described above. The beginning. That is, the transmission/reception start determination unit 211 completes the random storage. When the program is fetched, the transmission of the downlink data and the reception of the uplink data are started with respect to the added or unloaded bearer. When the random access procedure is not used, the transmission/reception start judging section 211 adds or is unloaded when the channel with the core network is established, more specifically, when the SCG attach/modify response is received from the MeNB. The bearer starts the transmission of the downlink data, and starts receiving the uplink data when the SCG attach/modify request is sent.

<In the case of the first addition of SeNB cells>

When the cells of the SeNB are added for the first time, the MeNB may offload the bearer in the MeNB communication to the SeNB (conversion). In this case, the random access procedure performed by the UE is used as an opportunity for both the UE and the SeNB to start transmitting and receiving uplink data and downlink data.

Fig. 7 shows a security key setting program and a transmission/reception start judging program in the embodiment of the present invention.

The UE periodically reports the measurement result (Meas Report) of the signal quality to the MeNB (S111). When the MeNB determines that the cell of the SeNB has to be added based on the measurement result, the SeNB generates the SeNB secure key SK _eNB (S113). In addition, the SeNB can be generated on each bearer with a security key, or every SCG. Next, in order to add the cells indicating the SeNB, the MeNB adds an SCG addition/modification instruction to the SeNB (S115). The SCG attach/modify indication includes bearer information (such as QoS (Quality of Service)) to be offloaded, a security key SK _eNB generated per SCC, and an SCC used to define the secure key SK _eNB . The SeNB attaches/modifies the SCG indication, sets the SeNB security key, and transmits the SCG attach/modify request to the MeNB (S117). The SCG attach/modify request includes, in addition to the information of the bearer that can be offloaded, an SCC, a DRB ID (Data Radio Bearer ID) or an SCG ID as a parameter of the security key notified to the UE. When the SeNB security key is generated for each bearer, the SCG attach/modify request contains the DRB ID, and when the SeNB security key is generated per SCG, the SCG attach/modify request contains the SCG ID. Further, the SCG addition/modification request includes a radio parameter for setting the SCG (for example, an EARFCN (E-UTRA Absolute Radio Frequency Channel Number), a PCI (Physical Cell Identity), or the like). The SeNB can use the SeNB security key when the SeNB transmits the SCG attach/modify request after the security key setting has been completed (S119).

The MeNB transmits the parameters of the security key included in the SCG attach/modify request to the UE by the RRC connection configuration reset (S121). That is, in the RRC connection configuration reset, in addition to the information of the bearer of the offload object, the SCC, the DRB ID or the SCG ID is included as a parameter of the security key notified to the UE. Further, the RRC connection configuration reset includes wireless parameters (eg, EARFCN, PCI, etc.) for setting the SCG.

The UE sets the SeNB security key SK _eNB using the SCC, and transmits the RRC connection configuration reset completion to the MeNB (S123) in order to report that the setting of the RRC connection configuration reset has been completed. The UE, when the setting of the SeNB security key is completed, can use the SeNB security key when the RRC connection configuration reset is transmitted (S125).

Next, the MeNB transmits the SCG attach/modify response as a response to the SCG attach/modify request to the SeNB (S127). Then, at The Path Switching Procedure for offloading the bearer is performed between the MeNB and the MME/S-GW (S129).

The UE notifies the SeNB of the completion of the setting of the security key, and implements a random access procedure (S131). When the random access procedure between the UE and the SeNB is completed, the UE starts the transmission of the uplink data and the reception of the downlink data using the security key by the SeNB (S133). Similarly, when the random access procedure between the UE and the SeNB is completed, the SeNB also uses the SeNB to start transmission of downlink data and reception of uplink data using the security key (S135).

<When a new bearer is added to the set SeNB>

When a new bearer is added to the SeNB that has been set as the SCG, the UE initiates the transmission and reception of the uplink data and the downlink data as the completion of the security key setting by the UE. Moreover, the opportunity for the SeNB to start the transmission of the downlink data is used as the establishment of the channel between the SeNB and the core network, and the opportunity for the SeNB to start receiving the uplink data is used as the security key set by the SeNB. carry out.

Fig. 8 is a view showing a security key setting program and a transmission/reception start judging program in the embodiment of the present invention.

When the SeNB is added as the SCG to add a new bearer, the MME/S-GW transmits a new E-RAB establishment request (New E-RAB establishment request) to the MeNB requesting the bearer (S210). Further, the UE periodically reports the measurement result of the signal quality (Meas Report) to the MeNB (S211).

The MeNB, upon receiving a new E-RAB setup request, generates a SeNB secure key SK _eNB (S213). Then, to indicate the addition of the new bearer, the MeNB transmits an SCG attach/modify indication to the SeNB (S215). The SCG attach/modify indication contains bearer information (eg, QoS) to be appended, a security key SK _eNB generated at each SCC, and an SCC used to define the secure key SK _eNB . The SeNB sets the SeNB security key for the SCG attach/modify indication, and transmits the SCG attach/modify request to the MeNB (S217). In the SCG attach/modify request, in addition to the information of the bearer that can be added, when the SeNB security key is generated for each bearer, the SCC and the DRB ID are also included. Further, the SCG attach/modify request includes a tunnel ID (GTP (GPRS Tunneling Protocol) ID). When the SeNB completes the setting of the SeNB security key and transmits the SCG addition/modification request, the SeNB can use the SeNB security key (S219). At this point in time, the SeNB starts receiving the uplink data using the SeNB security key (S220).

The MeNB transmits the parameters of the security key included in the SCG attach/modify request to the UE by the RRC connection configuration reset (S221). That is, in the RRC connection configuration reset, in addition to the information of the bearer of the additional object, the SeNB also includes the SCC and the DRB ID when the SeNB generates the security key for each bearer.

The UE, using the SCC, sets the SeNB security key SK _eNB , and transmits the RRC connection configuration reset completion to the MeNB in order to report that the setting of the RRC connection configuration reset has been completed (S223). The UE can use the SeNB security key when the SeNB security key setting is completed and the RRC connection configuration reset is transmitted (S225). At this point in time, the UE starts to use the transmission of the uplink data with the SeNB security key and the reception of the downlink data (S226).

Next, the MeNB will contain the IP address of the SeNB and the tunnel ID. The ERAB establishment response of the (GTP Tunnel ID) is sent to the MME/S-GW (S224) in response to the new E-RAB (Ground Wireless Access Network Radio) setup request, and the SCG is The attach/modify response is sent to the SeNB as a response to the SCG attach/modify request (S227). The SeNB, upon receiving the SCG attach/modify response, determines that the channel with the core network has been established, and starts transmitting the downlink data (S235).

Further, even if a new bearer has been added as the SeNB set by the SCG, a random access procedure used by the UE can be used as a trigger for starting transmission and reception of uplink data and downlink data by both the UE and the SeNB. At this time, after the UE sets the security key and becomes available (S223), the UE performs a random access procedure. When the random access procedure between the UE and the SeNB is completed, the UE uses the SeNB to start the transmission of the uplink data and the reception of the downlink data by using the security key. Similarly, when the random access handover has been completed between the UE and the SeNB, the SeNB also uses the SeNB to start the transmission of the downlink data and the reception of the uplink data by using the security key.

As described above, when the SeNB generates the security key for each SCG, the set SeNB security key is used when the SeNB cell is added. Therefore, the SeNB may not use the security key as the new bearer is added. Therefore, S213 of FIG. 8 is not implemented, and the information of the SeNB security key is not transmitted and received, but other programs can be implemented in the same manner.

Specifically, when receiving the new E-RAB establishment request, the MeNB sends an SCG attach/modify indication to the indication of the addition of the new bearer. SeNB (S215). The SCG attach/modify indication contains bearer information (eg, QoS) to be appended. The SeNB attaches/modifies the indication to the SCG, and transmits an SCG attach/modify request to the MeNB (S217). The SCG attach/modify request contains information of the bearer that can be appended. Further, the SCG attach/modify request contains a tunnel ID (GTP ID). The SeNB can use the SeNB security key for the newly added bearer when the SCG attach/modify request is transmitted (S219). At this point in time, the SeNB starts receiving the uplink data with the SeNB security key (S220).

The MeNB resets the RRC connection configuration, and transmits the information of the bearer of the additional object to the UE (S221).

The UE, in order to report that the setting of the RRC connection configuration reset has been completed, transmits the RRC connection configuration reset completion to the MeNB (S223). The UE can use the SeNB security key (S225) with respect to the newly added bearer at the time when the RRC connection configuration reset is transmitted. At this point in time, the UE first starts transmission of uplink data and reception of downlink data using the security key using the SeNB for the newly added bearer (S226).

Next, the MeNB establishes an ERAB setup response containing the IP address of the SeNB and the tunnel ID (GTP Tunnel ID) as a response to the new E-RAB setup request, and sends it to the MME/S-GW (S224), and The SCG attach/modify request is sent to the SeNB as a response to the SCG attach/modify request (S227). When receiving the SCG attach/modify response, the SeNB judges that the channel with the core network has been established, and starts transmitting the downlink data (S235).

At this time, a random access procedure by the UE may also be used. When the random access procedure is completed between the UE and the SeNB, the UE starts the transmission of the uplink data and the reception of the downlink data by using the SeNB using the security key. Similarly, when the random access procedure is completed between the UE and the SeNB, the SeNB also uses the SeNB to start the transmission of the downlink data and the reception of the uplink data using the security key.

<When the set SeNB will be offloaded in the MeNB communication>

When the SeNB set as the SCG is to be offloaded in the MeNB communication, the UE starts the transmission and reception of the uplink data and the downlink data, and the completion of the setting of the security key by the UE. In addition, when the SeNB starts the transmission of the downlink data, it is used as a channel between the SeNB and the core network, and the SeNB starts the reception of the uplink data, and acts as a security key for the SeNB. The setting is completed.

Fig. 9 is a view showing a security key setting program and a transmission/reception start judging program in the embodiment of the present invention.

When the SeNB that has been set as the SCG is to be offloaded in the MeNB communication, the MeNB generates the SeNB security key SK _eNB (S313). In addition, the UE has periodically reported the measurement result (Meas Report) of the signal quality to the MeNB (S311). Next, in order to indicate offloading of the bearer, the MeNB transmits an SCG attach/modify indication to the SeNB (S315). The SCG attach/modify indication contains bearer information (eg, QoS) to be offloaded, a security key SK _eNB generated at each SCC, and an SCC used to define the secure key SK _eNB . The SeNB sets the SeNB security key for the SCG attach/modify indication, and transmits the SCG attach/modify request to the MeNB (S317). In the SCG attach/modify request, in addition to the information of the bearer that can be offloaded, the SeNB also includes the SCC and the DRB ID when the bearer is generated by the security key. When the SeNB completes the setting of the SeNB security key and transmits the SCG addition/modification request, the SeNB can use the SeNB security key (S319). At this point in time, the SeNB starts receiving the uplink data with the SeNB security key (S320).

The MeNB resets the RRC connection configuration, and transmits the parameters of the security key included in the SCG attach/modify request to the UE (S321). That is, in the RRC connection configuration reset, in addition to the information of the bearer of the offload object, the SeNB also includes the SCC and the DRB ID when the SeNB generates the security key for each bearer.

The UE uses the SCC, sets the SeNB security key SK _eNB , and transmits the RRC connection configuration reset completion to the MeNB (S323) in order to report that the setting of the RRC connection configuration reset has been completed. The UE can use the SeNB security key (S325) when the SeNB security key setting has been completed and the RRC connection configuration reset is transmitted. At the time of the point, the UE starts to use the transmission of the uplink data with the SeNB security key and the reception of the downlink data (S326).

Next, the MeNB transmits the SCG attach/modify response as a response to the SCG attach/modify request to the SeNB (S327). Then, a channel conversion procedure for offloading the bearer between the MeNB and the MME/S-GW is performed (S329). When the SeNB has received the SCG attach/modify response, it determines that the channel with the core network has been established, and starts the transmission of the downlink data (S335).

Moreover, even when the SeNB that has been set to the SCG is offloaded to the bearer in the MeNB communication, the UE random access procedure can also be used as the UE and Both SeNBs start the transmission and reception of uplink data and downlink data. At this time, after the UE sets the security key and becomes available (S323), the UE performs a random access procedure. When the random access procedure between the UE and the SeNB is completed, the UE uses the SeNB to start the transmission of the uplink data and the reception of the downlink data by using the security key. Similarly, when the random access procedure between the UE and the SeNB is completed, the SeNB also uses the SeNB to start the transmission of the downlink data and the reception of the uplink data using the security key.

As described above, when the SeNB security key is generated for each SCG, since the SeNB security key is used when the cell of the SeNB is added, the SeNB may not use the security key as the new bearer is added. Therefore, S313 of FIG. 9 is not implemented, and the SeNB does not receive the information of the security key, but other programs are still implemented.

Specifically, to indicate offloading of the bearer, the MeNB transmits an SCG attach/modify indication to the SeNB (S315). The SCG attach/modify indication contains bearer information (eg, QoS) to be unloaded. The SeNB attaches/modifies the indication with respect to the SCG, and transmits an SCG attach/modify request to the MeNB (S317). The SCG attach/modify request contains information about the bearer that can be unloaded. When the SeNB transmits the SCG attach/modify request, the SeNB can use the SeNB security key for the offloaded bearer (S319). At this point in time, the SeNB starts receiving the uplink data with the SeNB security key (S320).

The MeNB transmits the information of the bearer of the unloading object to the UE by the RRC connection configuration reset (S321).

The UE, in order to report that the setting of the RRC connection configuration reset has been completed, transmits the RRC connection configuration reset completion to the MeNB (S323). UE When the RRC connection configuration reset is transmitted, the SeNB security key can be used (S325). At this point in time, the UE starts to use the transmission of the uplink data with the SeNB security key and the reception of the downlink data (S326).

Next, the MeNB transmits the SCG attach/modify response as a response to the SCG attach/modify request to the SeNB (S327). Then, a channel conversion procedure for offloading the bearer is performed between the MeNB and the MME/S-GW (S329). When receiving the SCG attach/modify response, the SeNB determines that a path with the core network has been established, and starts transmission of downlink data (S335).

At this time, a random access procedure by the UE may also be used. When the random access procedure between the UE and the SeNB is completed, the UE uses the SeNB to start the transmission of the uplink data and the reception of the downlink data by using the security key. Similarly, when the random access procedure between the UE and the SeNB is completed, the SeNB also uses the SeNB to start the transmission of the downlink data and the reception of the uplink data using the security key.

<Effects of Embodiments of the Invention>

According to the embodiment of the present invention, in the double connection, the timing of the security key setting is grasped, whereby the start of transmission/reception can be appropriately judged.

For this reason, the timing difference caused by the security key can be avoided.

In the case where the set SeNB adds a new bearer or when the set SeNB is to unload the bearer in the MeNB, in order to judge the start of transmission/reception, a random access procedure may be used, and a random access procedure is not required. By not using a random access program, you can avoid having it set He carries the situation of being interrupted instantaneously due to random access procedures.

For convenience of description, the base station and the mobile station in the embodiments of the present invention are illustrated by using a functional block diagram, but the base station and the mobile station in the embodiments of the present invention may also be implemented by hardware, software, or the like. . Further, each functional unit can be used in combination as needed. Further, the method of the embodiment of the present invention may be carried out in a different order from that shown in the embodiment.

In the above, it is explained that the timing of the security key setting is grasped in the double connection, and the method of appropriately determining the start of transmission/reception is described. However, the present invention is not limited to the above embodiment, and various changes can be made within the scope of the request. application.

Regarding the above embodiments, the following items are further disclosed.

(1) A mobile station is a cell group communication under the jurisdiction of a different base station, comprising: a receiving unit that receives parameters of a security key for communicating with a secondary cell group from a base station of the primary cell group; security key setting a security key for communicating with the secondary cell group; the security key setting completion notification unit notifies the base station of the secondary cell group of the completion of the setting of the security key by the random access procedure; and the transmission/reception start The judging unit starts transmission of uplink data and reception of downlink data by using the set security key when the random access procedure is completed.

(2) A mobile station that uses cell group communication under the jurisdiction of different base stations, including: The receiving unit receives parameters of a security key for communicating with the secondary cell group from a base station of the primary cell group; a security key setting unit sets a security key for communicating with the secondary cell group; and transmits/receives a start judgment When the security key is set, the transmission of the uplink data and the reception of the downlink data are started using the set security key.

(3) A method for judging transmission/reception at a mobile station, which is a method for using a mobile station for cell group communication under different base stations, comprising the steps of: receiving a sub-cell from a base station of a main cell group The parameter of the security key of the group communication; setting a security key for communicating with the secondary cell group; notifying the base station of the secondary cell group by completing the setting of the security key by using a random access procedure; and in the random access procedure When completed, the transmission of the uplink data and the reception of the downlink data are started using the set security key.

(4) A method for determining a transmission/reception start, which is a method for using a mobile station for cell group communication under different base stations, comprising the steps of: receiving security for communication with a secondary cell group from a base station of a primary cell group; The key of the key; the security key used to communicate with the secondary cell group; and when the security key setting is completed, use the set security key, The transmission of uplink data and the reception of downlink data are started.

(5) A base station, which is a base station in a wireless system in which a mobile station uses cell group communication under different base stations, and includes: a receiving unit that receives from the base station of the main cell group to make the mobile station and the secondary cell group The security key of the communication; the security key setting unit sets a security key for communicating the mobile station with the secondary cell group; and the transmitting unit, via the base station of the primary cell group, is used to make the mobile station and the secondary cell The parameters of the security key of the group communication are sent to the mobile station; and the random access procedure is used to grasp the completion of the setting of the security key in the mobile station, and the transmission of the uplink data is started and the downlink is started by using the set security key. Reception of road data.

(6) A base station, which is a base station in a wireless system in which a mobile station uses cell group communication under different base stations, and includes: a receiving unit that receives from the base station of the main cell group to make the mobile station and the secondary cell group The security key of the communication; the security key setting unit sets a security key for communicating the mobile station with the secondary cell group; and the transmitting unit, via the base station of the primary cell group, is used to make the mobile station and the secondary cell The parameters of the security key of the group communication are sent to the mobile station; and when a response is received from the base station of the primary cell group relative to the setting request of the parameter containing the security key for communicating the mobile station with the secondary cell group, Master the completion of the setting of the security key in the mobile station, use the set security key, start the transmission of the downlink data, and the security in the base station When the setting of the full key is completed, the received security data is used to start receiving the uplink data.

(7) A method for determining a transmission/reception start, which is a method for a base station in a wireless system in which a mobile station uses cell group communication under different base stations, and includes the following steps: receiving from a base station of a primary cell group to enable a security key for communicating between the mobile station and the secondary cell group; setting a security key for communicating the mobile station with the secondary cell group; and using the base station of the primary cell group to communicate the mobile station with the secondary cell group The parameters of the security key are sent to the mobile station; the parameters of the security key used to communicate the mobile station and the secondary cell group are transmitted to the mobile station via the base station of the primary cell group; and the mobile station is grasped by the random access procedure. After the setting of the security key is completed, the transmission of the uplink data and the reception of the downlink data are started using the set security key.

(8) A method for determining a transmission/reception start, which is a method for a base station in a wireless system in which a mobile station uses cell group communication under different base stations, comprising the steps of: receiving from a base station of a primary cell group to enable a security key for communicating between the mobile station and the secondary cell group; setting a security key for communicating the mobile station with the secondary cell group; and using the base station of the primary cell group to secure the mobile station to communicate with the secondary cell group Key parameters are sent to the mobile station; received from the base station of the primary cell group relative to the containment to make the action When responding to the request for setting the parameters of the security key for communication between the station and the secondary cell group, the completion of the setting of the security key in the mobile station is completed, and the transmission of the downlink data is started using the set security key, and When the setting of the security key in the base station is completed, the received security data is used to start receiving the uplink data.

(9) A mobile station that uses cell group communication under the jurisdiction of different base stations, including: a receiving unit that receives information from a base station of the primary cell group, adds new information to the secondary cell group, or unloads to the secondary cell group And the information carried in the base station communication of the main cell group; the security key setting completion notification unit notifies the completion of the setting of the bearer to the base station of the secondary cell group by the random access procedure; and the transmission/reception starts judgment When the random access procedure is completed, the uplink data transmission and the downlink data reception are started with respect to the added new bearer or the unloaded bearer.

(10) A mobile station that uses cell group communication under the jurisdiction of different base stations, including: a receiving unit that receives information from a base station of the primary cell group, adds new information to the secondary cell group, or unloads to the secondary cell group And the information of the bearer in the base station communication of the main cell group; and the transmission/reception start judging unit, when the setting of the bearer is completed, the uplink data transmission is started with respect to the additional new bearer or the unloaded bearer. Reception of downlink data.

(11) A method of determining the start of transmission/reception, which is different in use The method for controlling the mobile station group of the cell group under the jurisdiction of the base station includes the steps of: receiving information from the base station of the main cell group to the new bearer added to the secondary cell group, or unloading to the secondary cell group and in the main cell group The information carried in the base station communication; the random access procedure is used to notify the base station of the secondary cell group of the completion of the setting of the bearer; and when the random access procedure is completed, the new bearer is added or unloaded. Bearer, start transmission of uplink data and reception of downlink data.

(12) A method for judging transmission/reception starting, which is a mobile station using a cell group communication under different base stations, comprising the steps of: receiving a new bearer added to the sub-cell group from a base station of the main cell group Information, or information that is unloaded to the secondary cell group and carried in the base station communication of the primary cell group; and when the setting of the bearer is completed, the uplink data is started with respect to the additional new bearer or the unloaded bearer. The transmission and reception of downlink data.

(13) A base station, which is a base station in a wireless system in which a mobile station uses cell group communication under different base stations, and includes: a receiving unit that receives a new bearer added to the secondary cell group from a base station of the main cell group Information, or information carried in the base station communication of the primary cell group after unloading to the secondary cell group; The transmitting unit transmits the information of the added new bearer or the information of the unloaded bearer to the mobile station via the base station of the main cell group; and the transmission/reception start determining unit, and grasps the bearer in the mobile station by the random access procedure. After the setting is completed, the transmission of the downlink data and the reception of the uplink data are started with respect to the additional new bearer or the unloaded bearer.

(14) A base station, which is a base station in a wireless system in which a mobile station uses a cell group communication under the jurisdiction of a different base station, and includes: a receiving unit that receives a new bearer added to the secondary cell group from a base station of the main cell group The information, or the information carried in the base station communication of the primary cell group after unloading to the secondary cell group; the transmitting unit, via the base station of the primary cell group, adds the information of the new bearer or the unloaded bearer. The information is transmitted to the mobile station; and the transmission/reception start determination unit receives the response request from the base station of the main cell group with respect to the information including the information of the added new bearer or the information of the unloaded bearer. The completion of the setting of the bearer, the transmission of the downlink data is started with respect to the added new bearer or the unloaded bearer, and when the setting of the bearer in the base station is completed, the new bearer or the unloaded bearer is started. Receive of uplink data.

(15) A method for determining a transmission/reception start, which is a method for a base station in a wireless system in which a mobile station uses cell group communication under different base stations, and includes the following steps: receiving from the base station of the main cell group to the base station Information about the new carrying of the secondary cell population, or information carried in the base station communication that is unloaded to the secondary cell population and in the primary cell population; Sending information of the newly added bearer or the information of the unloaded bearer to the mobile station via the base station of the main cell group; by means of the random access procedure, grasping the completion of the setting of the bearer in the mobile station, regarding the additional new bearer or The offloaded bearer starts the transmission of downlink data and the reception of uplink data.

(16) A method for determining a transmission/reception start, which is a method for a base station in a wireless system in which a mobile station uses cell group communication under different base stations, and includes the following steps: receiving from the base station of the main cell group to the base station Information about the new bearer of the secondary cell population, or the information carried in the base station communication of the primary cell group after unloading to the secondary cell group; the information of the newly added new bearer is unloaded via the base station of the primary cell group The carried information is sent to the mobile station; when receiving a response request from the base station of the primary cell group relative to the information containing the information of the added new bearer or the information of the unloaded bearer, the setting of the bearer in the mobile station is grasped. Completion, with regard to the additional new bearer or the unloaded bearer, start the transmission of the downlink data, and when the setting of the bearer in the base station is completed, the uplink data is started with respect to the additional new bearer or the unloaded bearer. receive.

The international application is based on the priority of the Japanese Patent Application No. 2014-060939 filed on March 24, 2014, and the entire contents of the Japanese Patent Application No. 2014-060939. .

S111, S113, S115, S117, S119, S121, S123, S125, S127, S129, S131, S133, S135‧‧ steps

Claims (8)

A mobile station that uses cell group communication under the jurisdiction of different base stations, comprising: a receiving unit that receives parameters of a security key for communicating with the secondary cell group from a base station of the primary cell group; a security key setting unit, setting a security key for communicating with the secondary cell group; a security key setting completion notification unit, by means of a random access procedure, notifying the base station of the secondary cell group of completion of the setting of the security key; and transmitting/receiving start determining unit, When the random access procedure is completed, the transmission of the uplink data and the reception of the downlink data are started using the set security key. A mobile station that uses cell group communication under the jurisdiction of different base stations, comprising: a receiving unit that receives parameters of a security key for communicating with the secondary cell group from a base station of the primary cell group; a security key setting unit, setting The security key for communicating with the secondary cell group; and the transmission/reception start determining unit, when the security key setting is completed, starts the transmission of the uplink data and the downlink data by using the set security key. Reception. A base station is a base station in a wireless system in which a mobile station uses cell group communication under different base stations, and includes: The receiving unit receives a security key for communicating the mobile station with the secondary cell group from the base station of the primary cell group; the security key setting unit sets a security key for communicating the mobile station with the secondary cell group; And transmitting, via the base station of the main cell group, parameters of the security key for communicating the mobile station and the secondary cell group to the mobile station; and transmitting/receiving the start determining unit, and grasping the mobile station by the random access procedure After the setting of the security key is completed, the transmission of the downlink data and the reception of the uplink data are started using the set security key. A base station is a base station in a wireless system in which a mobile station uses a cell group communication under different base stations, and includes: a receiving unit that receives a base station from the main cell group to receive communication between the mobile station and the secondary cell group. a security key; a security key setting unit that sets a security key for communicating the mobile station with the secondary cell group; and a transmitting unit that communicates with the secondary cell group via the base station of the primary cell group The parameter of the key is transmitted to the mobile station; and the transmission/reception start determination unit receives the setting request for the parameter containing the security key for communicating the mobile station with the secondary cell group from the base station of the primary cell group. In response, when the completion of the setting of the security key in the mobile station is completed, the transmission of the downlink data is started using the set security key, and when the setting of the security key in the base station is completed, the set is used. Security key, start receiving uplink data. A mobile station that uses cell group communication under the jurisdiction of different base stations, comprising: a receiving unit, receiving information from a base station of the main cell group, receiving new information to the secondary cell group, or unloading to the secondary cell group and The information of the bearer in the base station communication of the cell group; the security key setting completion notification unit, by means of the random access procedure, notifies the base station of the secondary cell group of the completion of the setting of the bearer; and the transmission/reception start judgment unit, at random When the access procedure is completed, the uplink data transmission and the downlink data reception are started with respect to the added new bearer or the unloaded bearer. A mobile station that uses cell group communication under the jurisdiction of different base stations, comprising: a receiving unit, receiving information from a base station of the main cell group, receiving new information to the secondary cell group, or unloading to the secondary cell group and The information of the bearer in the base station communication of the cell group; and the transmission/reception start judging section, when the bearer setting is completed, the uplink data transmission and the downlink are started with respect to the additional new bearer or the unloaded bearer. Reception of data. A base station is a base station in a wireless system in which a mobile station uses a cell group communication under different base stations, and includes: a receiving unit that receives information of a new bearer added to the secondary cell group from a base station of the main cell group, Or the information of the bearer that is unloaded to the secondary cell group and in the base station communication of the primary cell group; the transmitting unit adds the new bearer through the base station of the primary cell group. The information or the information of the unloaded bearer is sent to the mobile station; and the transmission/reception start judging section grasps the completion of the setting of the bearer in the mobile station by the random access procedure, and starts with the additional new bearer or the unloaded bearer. Transmission of downlink data and reception of uplink data. A base station is a base station in a wireless system in which a mobile station uses a cell group communication under different base stations, and includes: a receiving unit that receives information of a new bearer added to the secondary cell group from a base station of the main cell group, Or the information of the bearer that is unloaded to the secondary cell group and in the base station communication of the main cell group; the transmitting unit sends the information of the newly added new bearer or the information of the unloaded bearer to the action via the base station of the main cell group. And the transmission/reception start determining unit grasps the security key in the mobile station when receiving a response request from the base station of the primary cell group with respect to the information including the information of the added new bearer or the information of the unloaded bearer After the setting is completed, the transmission of the downlink data is started with respect to the added new bearer or the unloaded bearer, and when the bearer setting in the base station is completed, the uplink is started with respect to the added new bearer or the offloaded bearer. Reception of data.