Mobile communication method and radio access network device

The present invention relates to a mobile communication method and a radio access network device.

In a mobile communication system in which a WCDMA (Wideband-CDMA) mobile communication system and an LTE (Long Term Evolution) mobile communication system coexist, between the WCDMA mobile communication system and the LTE mobile communication system, each It is configured to be able to perform Inter-RAT (Radio Access Technology) mobility control for mobile station UE.

<p><patcit num="1"><text>Japanese Unexamined Patent Publication No. 2009-17342</text></patcit></p>

<p> However, from the state in which the mobile station UE has established an RRC connection with the WCDMA mobile communication system (for example, the Cell PCH state), the LTE system is not grasped by the WCDMA mobile communication system. When transitioning to a state in which an RRC connection is established with a mobile communication system (for example, a Connected state), there is a problem that the resource for the RRC connection cannot be released immediately.</p><p> In addition, when the mobile station UE does not give a release notification to the WCDMA mobile communication system in Inter-RAT mobility control such as NAS (Non Access Stratum) recovery, it moves by reconnection or the like in the WCDMA mobile communication system. Since it is not possible to determine whether or not the station UE is in a state of returning the communication in the WCDMA mobile communication system again, there is a problem that the resource for the RRC connection cannot be released immediately.</p><p> Therefore, the present invention has been made in view of the above-mentioned problems, and in the inter-RAT mobility control for a mobile station, an RRC connection resource established with the mobile station in the transition source mobile communication system. It is an object of the present invention to provide a mobile communication method and a radio access network device capable of efficiently releasing the above.</p>

<p> The first feature of the present invention is a mobile communication method, in which a mobile station in a state where a wireless connection is established with a wireless access network device of the first communication method is a mobile communication system of the first communication method. When the service is out of service area, the location registration process for the mobile communication system of the second communication method or the process of establishing a wireless connection with the wireless access network device of the second communication method is performed without performing the location registration process. Steps to be performed and when the exchange station of the first communication method receives a predetermined signal, the position of the mobile station with respect to the mobile communication system of the second communication method with respect to the radio access network device of the first communication method. The step of notifying that the registration process or the process of establishing a wireless connection with the wireless access network device of the second communication method has been performed, and the wireless access network device of the first communication method are the first. (1) In response to the notification from the communication type exchange, the mobile station has a step of releasing the resource without transmitting a signal for releasing the resource for the wireless connection. It is a summary.</p><p> The second feature of the present invention is that the wireless access network device of the first communication method is in a state where the mobile station establishes a wireless connection with the wireless access network device of the first communication method. When recognizing, the location registration process for the mobile communication system of the second communication system of the mobile station from the exchange station of the first communication system, or the wireless access of the second communication system without performing the location registration process. When a notification indicating that the wireless connection establishment process with the network device has been performed is received, the mobile station is not sent a signal for releasing the resource for the wireless connection. The gist is to include a resource management unit configured to release the resource.</p>

<p> As described above, according to the present invention, in the inter-RAT mobility control for a mobile station, the RRC connection resource established with the mobile station in the transition source mobile communication system is efficiently released. It is possible to provide a mobile communication method and a radio access network device that can be used.</p>

<figref num="1">It is an overall block diagram of the mobile communication system which concerns on 1st Embodiment of this invention.</figref><figref num="2">It is a functional block diagram of the wireless line control station which concerns on 1st Embodiment of this invention.</figref><figref num="3">It is a functional block diagram of the exchange which concerns on 1st Embodiment of this invention.</figref><figref num="4">It is a functional block diagram of the movement management server which concerns on 1st Embodiment of this invention.</figref><figref num="5">It is a sequence diagram which shows the operation of the mobile communication system which concerns on 1st Embodiment of this invention.</figref>

(Structure of Mobile Communication System According to First Embodiment of the Present Invention) The configuration of the mobile communication system according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4.

The mobile communication system according to the present embodiment includes a WCDMA mobile communication system (radio access network) as a mobile communication system (radio access network) of the first communication method, and a mobile communication system (radio access network) of the second communication method. As an access network), it is equipped with an LTE mobile communication system (radio access network).

Specifically, as shown in FIG. 1, the mobile communication system according to the present embodiment exchanges the WCDMA exchange station SGSN, the WCDMA radio access network device, the radio line control station RNC, and the LTE system. It is equipped with a station MME, a radio base station eNB which is an LTE radio access network device, and a mobile management server HLR (Home Location Register) connected to a WCDMA switch station SGSN and an LTE switch station MME. ing.

The mobile communication system according to the present embodiment is configured to be capable of performing Inter-RAT control on the mobile station UE.

That is, in the mobile communication system according to the present embodiment, the mobile station UE has an RRC connection established with the WCDMA mobile communication system (for example, a Cell PCH state) and an LTE mobile communication system. It is configured so that it can transition between the state in which an RRC connection is established with and (for example, the Connected state).

As shown in FIG. 2, the wireless line control station RNC includes a receiving unit 11, a resource management unit 12, and a transmitting unit 13.

The receiving unit 11 is configured to receive various signals transmitted by the mobile station UE, the switching station SGSN, and the like.

The resource management unit 12 is configured to manage resources for the RRC connection established between the wireless line control station RNC and the mobile station UE.

Specifically, the resource management unit 12 allocates resources for such an RRC connection when an RRC connection is established between the wireless line control station RNC and the mobile station UE, and when the RRC connection is released. It is configured to free resources for such RRC connections.

Here, when the resource management unit 12 recognizes that the mobile station UE is in a state of establishing an RRC connection with the wireless line control station RNC, the LTE of the mobile station UE is transmitted from the exchange station SGSN. When a notification indicating that the location registration process has been performed for the mobile communication system of the method is received, such resources are released without transmitting a signal for releasing the resources for the RRC connection to the mobile station UE. It is configured to do.

In the mobile communication system according to the present embodiment, when ISR (Idle Mode Signaling Reduction) is applied in the Inter-RAT mobility control, the location registration process of the mobile station UE can be omitted.

Therefore, when the resource management unit 12 recognizes that the mobile station UE is in a state of establishing an RRC connection with the wireless line control station RNC, the mobile station UE uses the LTE system from the switching station SGSN. When the mobile station UE receives an area notification for the LTE mobile communication system indicating that the RRC connection has been established with the wireless base station eNB without performing the location registration process for the mobile communication system of Is configured to release such resources without sending a signal to release the resources for the RRC connection.

The transmission unit 13 is configured to transmit various signals to the mobile station UE, the exchange station SGSN, and the like.

As shown in FIG. 3, the exchange SGSN includes a receiving unit 21 and a transmitting unit 22.

The receiving unit 21 is configured to receive various signals transmitted by the mobile station UE, the wireless line control station RNC, the mobile management server HLR, and the like.

The transmission unit 22 is configured to transmit various signals to the mobile station UE, the wireless line control station RNC, the mobile management server HLR, and the like.

As shown in FIG. 4, the movement management server HLR includes a management unit 31, a location registration processing unit 32, and an instruction unit 33.

The management unit 31 is configured to manage information related to the mobile station UE whose location is registered with respect to the cell under the WCDMA mobile communication system and the cell under the LTE mobile communication system.

The location registration processing unit 32 is configured to transmit and receive signals related to location registration processing for the mobile station UE to and from the mobile station UE.

In the indicator 33, the mobile station UE in the state where the RRC connection is established with the wireless line control station RNC is out of service in the WCDMA mobile communication system, and the location registration process is performed for the LTE mobile communication system. When it detects that the above has been performed, it is configured to instruct the exchange SGSN to release the resources for the above-mentioned RRC connection by transmitting "Cancel Location".

(Operation of the mobile communication system according to the first embodiment of the present invention) The operation of the mobile communication system according to the first embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 4, in step S1001, it is detected that the mobile station UE in the state where the RRC connection is established with the wireless line control station RNC is out of service in the WCDMA mobile communication system.

In step S1002A, the mobile station UE decides to transition to the LTE mobile communication system. Here, the mobile station UE does not transmit a signal requesting the release of the resource for the RRC connection described above to the wireless line control station RNC.

On the other hand, in step S1002B, the wireless line control station RNC continues to wait for the reconnection request signal from the mobile station UE without releasing the resource for the RRC connection described above.

In step S1003, the mobile station UE transmits a location registration request signal such as Attach Request or Tracking Area Update to the exchange station MME.

In step S1004, the exchange MME transmits an Update Location Request to the mobile management server HLR in response to the location registration request signal received from the mobile station UE.

In step S1005, the mobility management server HLR sends an "Update Location Answer" to the exchange MME.

In step S1006, the exchange MME transmits a location registration response signal to the location registration request signal described above to the mobile station UE.

In step S1007, the mobile management server HLR sends a "Cancel Location" to the exchange SGSN.

In step S1008, the exchange SGSN transmits an "Iu Release Command" including "New Info" to the radio line control station RNC in response to the "Cancel Location".

Here, "Iu Release Command" is a RANAP signal instructing to release the RRC connection established between the mobile station UE and the wireless line control station RNC, and "New Info" is the mobile station UE. Information for notifying that the location registration process to the LTE mobile communication system has been performed (for example, predetermined information, predetermined flag, etc.).

In step S1009, the radio line control station RNC responds to the "Iu Release Command" including "New Info" to the mobile station UE, which is a signal for releasing the resource for the RRC connection "RRC Connection Release". Free such resources without sending.

Here, when the wireless line control station RNC receives the "Iu Release Command" including "New Info", the mobile station UE is transitioning from the WCDMA mobile communication system to the LTE mobile communication system. When the "RRC Connection Release" is sent to the mobile station UE, the "RRC Connection Release" is not received by the mobile station UE, so the "RRC Connection Release" is not sent to the mobile station UE. , Free resources for such RRC resources.

(Action / Effect of Mobile Communication System According to First Embodiment of the Present Invention) According to the mobile communication system according to the first embodiment of the present invention, the mobile station UE in a state where an RRC connection is established with the wireless line control station RNC is out of service in the WCDMA mobile communication system. When this is detected, the transition to the LTE mobile communication system is made without transmitting the signal requesting the release of the resources for the above-mentioned RRC connection to the wireless line control station RNC. Even so, the radio line control station RNC can efficiently release the resources for the above-mentioned RRC connection in response to the "Iu Release Command" including the "New Info" received from the switching station SGSN.

The features of the present embodiment described above may be expressed as follows.

The first feature of this embodiment is a mobile communication method in which an RRC connection (wireless connection) is established with a wireless line control station RNC (radio access network device of the first communication method). After the mobile station UE goes out of service in the WCDMA (first communication system) mobile communication system, the ISR is used in the location registration process for the LTE (second communication system) mobile communication system or in the Inter-RAT mobility control. If applied, the process of establishing an RRC connection with the radio base station eNB without performing such location registration processing and the switch station SGSN (first communication system exchange station) are "Cancel". When "Location (predetermined signal)" is received, the location registration process for the LTE mobile communication system of the mobile station UE or the RRC connection with the wireless base station eNB is performed for the wireless line control station RNC. The process of notifying that the establishment process has been performed, and the wireless line control station RNC sends a signal to the mobile station UE to release the resources for the RRC connection in response to the notification from the switching station SGSN. The gist is to have a process of releasing such resources without doing so.

The second feature of the present embodiment is when the wireless line control station RNC recognizes that the mobile station UE is in a state of establishing an RRC connection with the wireless line control station RNC. The location registration process of the mobile station UE to the LTE mobile communication system from the exchange station SGSN, or the RRC connection establishment process with the radio base station eNB was performed without performing such location registration process. When the notification indicating the above is received, the resource management unit 12 configured to release the resource for the RRC connection without transmitting the signal for releasing the resource to the mobile station UE is provided. The gist is that.

The operations of the mobile management server HLR, the switching station SGSN, the wireless line control station RNC, the switching station MME, the wireless base station eNB, and the mobile station UE described above may be performed by hardware or by a processor. It may be implemented by a software module or a combination of both.

Software modules include RAM (Random Access Memory), flash memory, ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electronically Erasable and Programmable ROM), registers, hard disks, and removable disks. Or, it may be provided in an arbitrary format storage medium such as a CD-ROM.

Such a storage medium is connected to the processor so that the processor can read and write information to the storage medium. Further, such a storage medium may be integrated in the processor. Further, such a storage medium and a processor may be provided in the ASIC. Such an ASIC may be provided in the mobile management server HLR, the switching station SGSN, the wireless line control station RNC, the switching station MME, the wireless base station eNB, or the mobile station UE. Further, such a storage medium and a processor may be provided as discrete components in the mobile management server HLR, the switching station SGSN, the wireless line control station RNC, the switching station MME, the wireless base station eNB, or the mobile station UE.

Although the present invention has been described in detail using the above-described embodiments, it is clear to those skilled in the art that the present invention is not limited to the embodiments described in the present specification. The present invention can be implemented as modifications and modifications without departing from the spirit and scope of the invention as defined by the claims. Therefore, the description of the present specification is for the purpose of exemplification and does not have any limiting meaning to the present invention.

RNC ... Wireless line control station 11, 21 ... Receiver 12 ... Resource Management Department 13, 22 ... Transmitter SGSN, MME ... Exchange HLR ... Mobile Management Server 31 ... Management Department 32 ... Location registration processing unit 33 ... Indicator UE ... mobile station