Patent Application
20150011205
One or more embodiments of the present invention relate to communication systems, mobility management entities, base stations, and communication methods, which are, in radio communication, suited for releasing E-UTRAN Radio Access Bearers (E-RABs) related to mobile stations.
In Universal Mobile Telecommunications System Long Term Evolution (UMTS LTE), a logical communication path referred to as an E-UTRAN Radio Access Bearer (E-RAB) is set between a mobile station (UE) and a node within a core network. E-UTRAN is an abbreviation for Evolved Universal Terrestrial Radio Access Network. When communication terminates, the E-RAB is released. An MME manages established E-RABs for purposes such as charging for communication.
In relation to a release of an E-RAB, the 3rd Generation Partnership Project (3GPP) defines messages exchanged between an MIME and a base station (eNB) (Non-patent Document 1). For the E-RAB release initiated by an MME, an E-RAB Release Command message is transmitted from the MME to an eNB (Sec. 8.2.3.2.1 of Non-patent Document 1). Upon receiving this message specifying an E-RAB to be released, the eNB releases the E-RAB and releases a Data Radio Bearer and radio resources corresponding to the E-RAB. For the E-RAB release initiated by the eNB, an E-RAB Release Indication message is transmitted from the eNB to the MME (Sec. 8.2.3.2.2 of Non-patent Document 1). Upon receiving this message specifying an E-RAB to be released, the MME initiates an appropriate procedure to release the E-RAB. Moreover, in relation to the E-RAB release, 3GPP defines an RRC Connection Reconfiguration message that is exchanged between an eNB and a UE (Sec. 5.3.5 of Non-patent Document 2).
An event can occur, for which E-RABs related to UEs should be released. For example, in the event of an impediment (failure) at an IP Multimedia Subsystem (IMS) while Voice over LTE (VoLTE), which communicates voice using packets, is in operation, the MME would detect the impediment. Similarly, in the event of an impediment in a physical line between the MIME and the eNB, the MME or the eNB would detect the impediment. Events for which E-RABs related to UEs should be released are not limited to these examples. In any case, E-RABs related to UEs communicating with the eNB cannot be maintained. Thus, a procedure for collectively releasing these E-RABs is needed.
In a conventionally proposed communication system to implement VoLTE, when many UEs are connected to the IMS and if an impediment in IMS communication is caused due to reasons such as a breakdown of an IMS device, E-RABs related to the UEs need to be released. On the other hand, E-RABs related to a non-voice call, which are established without involving the IMS, are preferably maintained established.
The procedure initiated by the MME in accordance with the conventional 3GPP specification for releasing E-RABs related to UEs is as described by referring to
On the other hand, if, for example, the eNB detects an impediment in a physical line between the MIME and the eNB, it is possible that the eNB initiates a procedure for releasing E-RABs related to UEs. This procedure is as described by referring to
In light of the situation above, the one or more embodiments of the present invention provide a communication system, a mobility management entity, a base station, and a communication method, each of which reduces a load placed on an MME on the release of multiple E-RABs related to multiple UEs.
In a first aspect according to one or more embodiments of the present invention, a communication system includes a base station and a mobility management entity. The mobility management entity includes: a detection unit configured to detect an opportunity to release E-UTRAN Radio Access Bearers (E-RABs) related to mobile stations; a mobility management entity transmitting unit configured to transmit a single E-RAB release information message that collectively specifies the E-RABs that are detected by the detection unit to be released to the base station communicating with the mobile stations; and a mobility management entity receiving unit configured to receive a single E-RAB release information acknowledge message from the base station. The base station includes: a base station receiving unit configured to receive the E-RAB release information message; and a base station transmitting unit configured to transmit, upon the base station receiving unit receiving the E-RAB release information message, the single E-RAB release information acknowledge message to the mobility management entity. The base station may further include a radio transmitting unit that is configured to command, after the base station receiving unit having received the E-RAB release information message, the mobile stations to release the respective E-RABs.
In the first aspect, when releasing E-RABs related to mobile stations, the mobility management entity transmits a single E-RAB release information message that collectively specifies to-be-released E-RABs to the base station, and receives a single E-RAB release information acknowledge message. Thus, a load placed on the MME on the release of the E-RABs related to the UEs can be reduced.
The mobility management entity may further include an E-RAB information updating unit that is configured to update, upon the mobility management entity receiving unit receiving the E-RAB release information acknowledge message, information related to the E-RABs so that the information indicates release of the E-RABs.
By the mobility management entity updating, after receiving an E-RAB release information acknowledge message from the base station, information related to to-be-released E-RABs so that the information indicates release of the E-RABs, an inconsistency between E-RABs that are actually established and information that is managed by the mobility management entity can be avoided. Updating the information so that the information indicates the release of the E-RABs includes, for example, deleting the released E-RABs from records that are related to established E-RABs and are in the mobility management entity.
The mobility management entity transmitting unit may retransmit the E-RAB release information message to the base station when the mobility management entity receiving unit does not receive the E-RAB release information acknowledge message from the base station in a predetermined amount of time after the mobility management entity transmitting unit has transmitted the E-RAB release information message to the base station.
By retransmitting the E-RAB release information message as described above, certainty that the E-RAB release information message reaches the base station can be increased.
The base station may further include an E-RAB information updating unit that is configured to update, after the base station receiving unit having received the E-RAB release information message, information related to the E-RABs so that the information indicates release of the E-RABs.
According to the configuration above, since the information managed by the base station is updated based on the E-RAB release information message transmitted by the mobility management entity, an inconsistency between the information managed by the mobility management entity and the information managed by the base station can be avoided.
In a second aspect according to one or more embodiments of the present invention, a communication system includes a base station and a mobility management entity. The base station includes: a detection unit configured to detect an opportunity to release E-RABs related to mobile stations with which the base station is communicating; a base station transmitting unit configured to transmit a single E-RAB release information message that collectively specifies the E-RABs that are detected by the detection unit to be released to the mobility management entity; and a base station receiving unit configured to receive a single E-RAB release information acknowledge message from the mobility management entity. The mobility management entity includes: a mobility management entity receiving unit configured to receive the E-RAB release information message; and a mobility management entity transmitting unit configured to transmit, upon the mobility management entity receiving unit receiving the E-RAB release information message, the single E-RAB release information acknowledge message to the base station. The base station may further include a radio transmitting unit that is configured to command, after the base station transmitting unit having transmitted the E-RAB release information message, the mobile stations to release the respective E-RABs.
In the second aspect, when releasing E-RABs related to mobile stations, the base station transmits a single E-RAB release information message that collectively specifies to-be-released E-RABs to the mobility management entity, and receives a single E-RAB release information acknowledge message. Thus, a load placed on the MME on the release of the E-RABs related to the UEs can be reduced.
The mobility management entity may further include an E-RAB information updating unit that is configured to update, after the mobility management entity receiving unit having received the E-RAB release information message, information related to the E-RABs so that the information indicates release of the E-RABs.
By the mobility management entity updating, after receiving an E-RAB release information message from the base station, information related to to-be-released E-RABs so that the information indicates release of the E-RABs, an inconsistency between E-RABs that are actually established and the information that is managed by the mobility management entity can be avoided. Updating the information so that the information indicates the release of the E-RABs includes, for example, deleting the released E-RABs from records that are related to established E-RABs and are in the mobility management entity.
The base station transmitting unit may retransmit the E-RAB release information message to the mobility management entity when the base station receiving unit does not receive the E-RAB release information acknowledge message from the mobility management entity in a predetermined amount of time after the base station transmitting unit has transmitted the E-RAB release information message to the mobility management entity.
By retransmitting the E-RAB release information message as described above, certainty that the E-RAB release information message reaches the mobility management entity can be increased. In particular, when there is an impediment, such as momentary interruption, in a physical line between the mobility management entity and the base station, it is possible that the E-RAB release information message will not reach the mobility management entity. Thus, it is preferable that the base station can retransmit the E-RAB release information message.
The base station may further include an E-RAB information updating unit configured to update, upon the base station receiving unit receiving the E-RAB release information acknowledge message, information related to the E-RABs so that the information indicates release of the E-RABs.
According to the configuration above, since the information managed by the base station is updated based on the E-RAB release information acknowledge message transmitted by the mobility management entity, an inconsistency between the information managed by the mobility management entity and the information managed by the base station can be avoided.
In the first aspect according to one or more embodiments of the present invention, a mobility management entity includes: a detection unit configured to detect an opportunity to release E-RABs related to mobile stations; a mobility management entity transmitting unit configured to transmit a single E-RAB release information message that collectively specifies the E-RABs that are detected by the detection unit to be released to a base station communicating with the mobile stations; and a mobility management entity receiving unit configured to receive a single E-RAB release information acknowledge message from the base station.
The mobility management entity may further include an E-RAB information updating unit configured to update, upon the mobility management entity receiving unit receiving the E-RAB release information acknowledge message, information related to the E-RABs so that the information indicates release of the E-RABs.
The mobility management entity transmitting unit may retransmit the E-RAB release information message to the base station when the mobility management entity receiving unit does not receive the E-RAB release information acknowledge message from the base station in a predetermined amount of time after the mobility management entity transmitting unit has transmitted the E-RAB release information message to the base station.
In the second aspect according to one or more embodiments of the present invention, a mobility management entity includes: a mobility management entity receiving unit configured to receive, from a base station, a single E-RAB release information message that collectively specifies E-RABs that are related to mobile stations with which the base station is communicating and are to be released; and a mobility management entity transmitting unit configured to transmit, upon the mobility management entity receiving unit receiving the E-RAB release information message, a single E-RAB release information acknowledge message to the base station.
The mobility management entity may further include an E-RAB information updating unit configured to update, after the mobility management entity receiving unit having received the E-RAB release information message, information related to the E-RABs so that the information indicates release of the E-RABs.
In the first aspect according to one or more embodiments of the present invention, a base station includes: a base station receiving unit configured to receive, from a mobility management entity, a single E-RAB release information message that collectively specifies E-RABs that are related to mobile stations with which the base station is communicating and are to be released; and a base station transmitting unit configured to transmit, upon the base station receiving unit receiving the E-RAB release information message, a single E-RAB release information acknowledge message to the mobility management entity. The base station may further include a radio transmitting unit configured to command, after the base station receiving unit having received the E-RAB release information message, the mobile stations to release the respective E-RABs.
The base station may further include an E-RAB information updating unit configured to update, after the base station receiving unit having received the E-RAB release information message, information related to the E-RABs so that the information indicates release of the E-RABs.
In the second aspect according to one or more embodiments of the present invention, a base station includes: a detection unit configured to detect an opportunity to release E-RABs related to mobile stations with which the base station is communicating; a base station transmitting unit configured to transmit a single E-RAB release information message that collectively specifies the E-RABs that are detected by the detection unit to be released to a mobility management entity; and a base station receiving unit configured to receive a single E-RAB release information acknowledge message from the mobility management entity. The base station may further include a radio transmitting unit configured to command, after the base station transmitting unit having transmitted the E-RAB release information message, the mobile stations to release the respective E-RABs.
The base station transmitting unit may retransmit the E-RAB release information message to the mobility management entity when the base station receiving unit does not receive the E-RAB release information acknowledge message from the mobility management entity in a predetermined amount of time after the base station transmitting unit has transmitted the E-RAB release information message to the mobility management entity.
The base station may further include an E-RAB information updating unit configured to update, upon the base station receiving unit receiving the E-RAB release information acknowledge message, information related to the E-RABs so that the information indicates release of the E-RABs.
In the first aspect according to one or more embodiments of the present invention, a communication method includes: in a mobility management entity, detecting an opportunity to release E-RABs related to mobile stations, and transmitting a single E-RAB release information message that collectively specifies the E-RABs to be released to a base station communicating with the mobile stations; and in the base station, transmitting, upon receiving the E-RAB release information message, a single E-RAB release information acknowledge message to the mobility management entity. The communication method may further include, in the base station, commanding, after receiving the E-RAB release information message, the mobile stations to release the respective E-RABs.
The communication method may further include, in the mobility management entity, updating, upon receiving the E-RAB release information acknowledge message, information related to the E-RABs so that the information indicates release of the E-RABs.
The communication method may further include, in the mobility management entity, retransmitting the E-RAB release information message to the base station when not receiving the E-RAB release information acknowledge message from the base station in a predetermined amount of time after having transmitted the E-RAB release information message to the base station.
The communication method may further include, in the base station, updating, after receiving the E-RAB release information message, information related to the E-RABs so that the information indicates release of the E-RABs.
In the second aspect according to one or more embodiments of the present invention, a communication method includes: in a base station that is communicating with mobile stations, detecting an opportunity to release E-RABs related to the mobile stations, and transmitting a single E-RAB release information message that collectively specifies the E-RABs to be released to a mobility management entity; and in the mobility management entity, transmitting, upon receiving the E-RAB release information message, a single E-RAB release information acknowledge message to the base station. The communication method may further include, in the base station, commanding, after transmitting the E-RAB release information message, the mobile stations to release the respective E-RABs.
The communication method may further include, in the mobility management entity, updating, upon receiving the E-RAB release information message, information related to the E-RABs so that the information indicates release of the E-RABs.
The communication method may further include, in the base station, retransmitting the E-RAB release information message to the mobility management entity when not receiving the E-RAB release information acknowledge message from the mobility management entity in a predetermined amount of time after having transmitted the E-RAB release information message to the mobility management entity.
The communication method may further include, in the base station, updating, upon receiving the E-RAB release information acknowledge message, information related to the E-RABs so that the information indicates release of the E-RABs.
With reference to the attached drawings, various embodiments according to the present invention are described below. For simplicity, it is assumed that communication systems according to one or more embodiments of the present invention have a configuration to implement VoLTE as described above by referring to
By referring to
As shown in
Upon receiving the E-RAB release information message, the eNB transmits a single E-RAB release information acknowledge message to the MME. After receiving the E-RAB release information message, the eNB commands the UEs to release the respective E-RABs. More specifically, after receiving the E-RAB release information message, the eNB transmits, in accordance with Sec. 5.3.5 of Non-patent Document 2, an RRC Connection Reconfiguration message to each of the UEs. Each UE performs, in accordance with the received RRC Connection Reconfiguration message, radio configuration (RRC connection reconfiguration) of its own device. After confirming completion of the radio configuration (RRC connection reconfiguration) of its own device, each UE transmits an RRC Connection Reconfiguration Complete message to the eNB.
The eNB may transmit the RRC Connection Reconfiguration message to each of the UEs after transmitting the E-RAB release information acknowledge message. The eNB may transmit the RRC Connection Reconfiguration message to each of the UEs before transmitting the E-RAB release information acknowledge message.
After receiving the E-RAB release information acknowledge message, the MIME may update information (E-RAB information) related to the E-RABs so that the information indicates release of the E-RABs. The concept “the MME may update information . . . so that the information indicates release of the E-RABs” includes, for example, deleting the released E-RABs from records (E-RAS information) that are related to established E-RABs and are in the MME.
The MME may update, before receiving the E-RAB release information acknowledge message, the information (E-RAB information) related to the E-RABs so that the information indicates the release of the E-RABs. Preferably, the update described above is performed in accordance with the E-RAB release information message.
Furthermore, the eNB may update, after transmitting the E-RAB release information acknowledge message, information (E-RAB information) related to the E-RABs so that the information indicates release of the E-RABs. The eNB may update, even before transmitting the E-RAB release information acknowledge message, if after having received the E-RAB release information message, the information (E-RAB information) related to the E-RABs so that the information indicates the release of the E-RABs.
In addition to performing the procedure described above, the MME may control other nodes so that the nodes perform procedures necessary for releasing E-RABs. For example, the MME may transmit a control message to a gateway to which to-be-released E-RABs are set to make the gateway release the E-RABs.
Subsequently, the MME determines whether the MME has received an E-RAB Release Information Acknowledge from the eNB (S50). The MME continues the determination described above until the timer set at step S30 expires (S50 and S60). If an E-RAB Release Information Acknowledge has not been received before the timer expires (S60: YES), the MIME restarts the timer (S30) and also retransmits the E-RAB release information message to the eNB (S40).
In other words, in the example of the control as shown in
On the other hand, if the MME receives the E-RAB release information acknowledge message from the eNB (S50: YES), the procedure returns to step S10 and the MME again performs detection of an E-RAB release opportunity. As described above, the MIME may update the E-RAB information in the MIME after receiving the E-RAS release information acknowledge message (S50: YES).
The control unit 100 of the MME may include an E-RAB information updating unit 104 that updates, upon the receiving unit (mobility management entity receiving unit) 120 receiving the E-RAB release information acknowledge message, information (E-RAB information) related to the E-RABs so that the information indicates release of the E-RABs. The E-RAB information can be stored in a storing unit 130.
As described above by referring to
The control unit 100 is a functional block performed by a central processing unit (CPU), which is in the MME and is not shown in the figure, executing a computer program stored in the storing unit 130 and functioning in accordance with the computer program.
The control unit 200 of the eNB may include an E-RAB information updating unit 204 that updates, upon the receiving unit 210 receiving the E-RAB release information message, information (E-RAB information) related to the E-RABs so that the information indicates release of the E-RABs. The E-RAB information can be stored in a storing unit 250.
The control unit 200 is a functional block performed by a CPU, which is in the eNB and is not shown in the figure, executing a computer program stored in the storing unit 250 and functioning in accordance with the computer program.
According to the configuration above, when releasing E-RABs related to UEs, the MIME transmits a single E-RAB release information message that collectively specifies to-be-released E-RABs to the eNB, and receives a single E-RAB release information acknowledge message. Thus, compared with a configuration in which the release of a single E-RAB requires a single message, a load placed on the MME on the release of E-RABs related to UEs can be reduced.
The MIME (control unit 100) can include an E-RAB information updating unit 104 that updates, upon the receiving unit 120 receiving an E-RAB release information acknowledge message, information (E-RAB information) related to E-RABs so that the information indicates release of the E-RABs.
According to the configuration above, since the MME updates, after receiving the E-RAB release information acknowledge message from the eNB, the information related to the to-be-released E-RABs so that the information indicates the release of the E-RABs, an inconsistency between E-RABs that are actually established and information that is managed by the MIME can be avoided.
The transmitting unit 110 (mobility management entity transmitting unit) of the MME may, when the receiving unit 120 does not receive the E-RAB release information acknowledge message from the eNB within a predetermined amount of time after the transmitting unit 110 has transmitted the E-RAB release information message to the eNB, retransmit the E-RAB release information message to the eNB. By retransmitting the E-RAB release information message as described above, certainty that the E-RAB release information message reaches the eNB can be increased.
According to the configuration above, since the MME specifies E-RABs to be released and commands the eNB to release the E-RABs, compared with a configuration in which all E-RABs are released by the Reset procedure performed between the MME and the eNB, E-RABs related to a non-voice call, which are established without involving the IMS, can be maintained established.
By referring to
Upon receiving the E-RAB release information message, the MATE transmits a single E-RAB release information acknowledge message to the eNB. After receiving the E-RAB release information acknowledge message, the eNB commands the UEs to release the respective E-RABs. More specifically, after receiving the E-RAB release information acknowledge message, the eNB transmits, in accordance with Sec. 5.3.5 of Non-patent Document 2, an RRC Connection Reconfiguration message to each of the UEs. Each UE performs, in accordance with the received RRC Connection Reconfiguration message, radio configuration (RRC connection reconfiguration) of its own device. After confirming completion of the radio configuration (RRC connection reconfiguration) of its own device, each UE transmits an RRC Connection Reconfiguration Complete message to the eNB.
The eNB may transmit, even before receiving the E-RAB release information acknowledge message, if after having determined the E-RABs to be released, the RRC Connection Reconfiguration messages to the UEs.
The eNB may transmit the E-RAB release information message before transmitting the RRC Connection Reconfiguration message. The eNB may transmit the E-RAB release information message after transmitting the RRC Connection Reconfiguration message.
After receiving the E-RAB release information message, the MME may update information (E-RAB information) related to the E-RABs so that the information indicates release of the E-RABs. The concept “the MME may update information . . . so that the information indicates release of the E-RABs” includes, for example, deleting the released E-RABs from records (E-RAB information) that are related to established E-RABs and are in the MIME. The MME may update the E-RAB information either before or after transmitting the E-RAB release information acknowledge message to the eNB.
Furthermore, the eNB may update, after receiving the E-RAB release information acknowledge message, information (E-RAB information) related to the E-RABs so that the information indicates release of the E-RABs. The eNB may update, even before receiving the E-RAB release information acknowledge message, if after having transmitted the E-RAB release information message, the information (E-RAB information) related to the E-RABs so that the information indicates the release of the E-RABs.
In addition to performing the procedure described above, the MME may control other nodes so that the nodes perform procedures necessary for releasing E-RABs. For example, the MME may transmit a control message to a gateway to which to-be-released E-RABs are set to make the gateway release the E-RABs.
Subsequently, the eNB determines whether the eNB has received an E-RAB Release Information Acknowledge from the MME (S150). The eNB continues the determination described above until the timer set at step S130 expires (S150 and S160). If an E-RAB Release Information Acknowledge has not been received before the timer expires (S160: YES), the eNB restarts the timer (S130) and also retransmits the E-RAB release information message to the MME (S140).
In other words, in the example of the control as shown in
On the other hand, if the eNB receives the E-RAB release information acknowledge message from the MIME (S150: YES), the eNB transmits, to the UEs, RRC Connection Reconfiguration messages commanding the UEs to release the respective E-RABs (S170). Each UE performs, in accordance with the received RRC Connection Reconfiguration message, radio configuration (RRC connection reconfiguration) of its own device, and then, transmits an RRC Connection Reconfiguration Complete message to the eNB. The eNB receives the RRC Connection Reconfiguration Complete message from each of the UEs (S180). Subsequently, the procedure returns to step S110, and the eNB again performs detection of an E-RAB release opportunity.
The control unit 100 of the MME may include an E-RAB information updating unit 104 that update, upon the receiving unit (mobility management entity receiving unit) 120 receiving the E-RAB release information message, information (E-RAB information) related to the E-RABs so that the information indicates release of the E-RABs. The E-RAB information can be stored in a storing unit 130.
The control unit 100 is a functional block performed by a CPU, which is in the MME and is not shown in the figure, executing a computer program stored in the storing unit 130 and functioning in accordance with the computer program.
The control unit 200 of the eNB may include an E-RAB information updating unit 204 that updates, upon the receiving unit 210 receiving the E-RAB release information acknowledge message, information (E-RAB information) related to the E-RABs so that the information indicates release of the E-RABs. The E-RAB information can be stored in a storing unit 250.
As described above by referring to
The control unit 200 is a functional block performed by a CPU, which is in the eNB and is not shown in the figures, executing a computer program stored in the storing unit 250 and functioning in accordance with the computer program.
According to the configuration above, when releasing E-RABs related to UEs, the eNB transmits a single E-RAB release information message that collectively specifies to-be-released E-RABs to the MME, and receives a single E-RAB release information acknowledge message. Thus, a load placed on the MME on the release of E-RABs related to UEs can be reduced.
The MME (control unit 100) can include an E-RAB information updating unit 104 that updates, after the receiving unit 120 having received the E-RAB release information message, information (E-RAB information) related to the E-RABs so that the information indicates release of the E-RABs.
According to the configuration above, since the MME updates, after receiving the E-RAB release information message from the eNB, the information related to the to-be-released E-RABs so that the information indicates the release of the E-RABs, an inconsistency between E-RABs that are actually established and information that is managed by, the MIME can be avoided.
The transmitting unit 220 (base station transmitting unit) of the eNB may, when the receiving unit 210 does not receive the E-RAB release information acknowledge message from the MME within a predetermined amount of time after the transmitting unit 220 has transmitted the E-RAB release information message to the MME, retransmit the E-RAB release information message to the MIME. By retransmitting the E-RAB release information message as described above, certainty that the E-RAB release information message reaches the MME can be increased. In particular, when there is an impediment, such as momentary interruption, in a physical line between the MME and the eNB, it is possible that the E-RAB release information message will not reach the MME. Thus, it is understood to be preferable that the eNB can retransmit the E-RAB release information message.
Other Modifications
The embodiments described above can be modified in various ways. Examples of modifications are described below. Two or more of the modifications can be combined as appropriate, provided that the combined modifications do not conflict with each other.
(1) Modification 1
A UE is a freely-chosen device capable of communicating wirelessly with an eNB. The UE may be, for example, a mobile phone terminal, a desktop personal computer, a laptop personal computer, an ultra-mobile personal computer (UMPC), a portable game console, or any other type of wireless terminal.
(2) Modification 2
Each function executed by a CPU in an MIME and an eNB may be executed by a piece of hardware instead of by a CPU, or by a programmable logic device such as a field programmable gate array (FPGA) and a digital signal processor (DSP).
Although the disclosure has been described with respect to only a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that various other embodiments may be devised without departing from the scope of the present invention. Accordingly, the scope of the invention should be limited only by the attached claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-050160 | Mar 2012 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2013/050730 | 1/17/2013 | WO | 00 |
