JP2011066943A - Mobile communication method, radio base station, and relay node - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile communication method that reduces interference within a relay node. <P>SOLUTION: The mobile communication method has: a step A in which, when a connection is established between a radio base station DeNB and a relay node RN, the radio base station DeNB notifies the relay node RN of predetermined timing; a step B in which the radio base station DeNB performs scheduling to transmit a downstream signal to the relay node RN at the predetermined timing; and a step C in which the relay node RN performs scheduling to transmit the downstream signal at timing other than the predetermined timing. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a mobile communication method, a radio base station, and a relay node.

  In an LTE-Advanced mobile communication system, which is a successor of LTE (Long Term Evolution), a function similar to that of the radio base station DeNB is provided between the mobile station UE and the radio base station DeNB (Donor eNB). It can be connected to a “Relay Node (RN) RN”.

  In the LTE-Advanced mobile communication system, an E-RAB (E-UTRAN Radio Access Bearer) is set between the mobile station UE and a core node CN (Core Node), and the mobile station UE and the relay node RN Between the relay node RN and the radio base station DeNB, the Un radio bearer is set, and the S1 bearer is set between the radio base station DeNB and the core node CN. It is configured.

3GPP TS 36.300 (V8.8.0), “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Network 9 H 3GPP TR36.814 (V1.0.0), “Further Advancements for E-UTRA Physical Layer Aspects”, February 2009 3GPP TS36.331 (V8.6.0), “Radio Resource Control (RRC); Protocol specification”, June 2009 3GPP R1-084686, “Updated WF on addressing forward compatibility in Rel-8”, November 2008

  However, in such a mobile communication system, downlink signal reception processing from the radio base station DeNB by the relay node RN (reception processing in the Un radio bearer) and downlink signal transmission processing to the mobile station UE by the relay node RN (Uu radio bearer) Transmission processing in the Uu radio bearer) and transmission processing of the uplink signal to the radio base station DeNB by the relay node RN. When the (transmission processing in the Un radio bearer) is performed at the same time, there is a problem in that the transmission signal of the relay node RN wraps around the receiver of the relay node RN itself and interference occurs.

  Therefore, the present invention has been made in view of the above-described problems, and reduces interference to the receiver of the relay node itself caused by simultaneous transmission / reception processing in the Un radio bearer and transmission / reception processing in the Uu radio bearer. It is an object of the present invention to provide a mobile communication method, a radio base station, and a relay node that can be used.

  A first feature of the present invention is a mobile communication method, wherein when a connection is set up between a radio base station and a relay node, the radio base station notifies the relay node of a predetermined timing. Step A in which the radio base station performs scheduling so that a downlink signal is transmitted to the relay node at the predetermined timing, and the relay node transmits a downlink signal at a timing other than the predetermined timing. It has a gist of having a process C for performing scheduling so as to transmit.

  A second feature of the present invention is a mobile communication method, wherein when a connection is set up between a radio base station and a relay node, the relay node notifies the radio base station of a predetermined timing. Step A in which the radio base station performs scheduling so that a downlink signal is transmitted to the relay node at the predetermined timing, and the relay node transmits a downlink signal at a timing other than the predetermined timing. It has a gist of having a process C for performing scheduling so as to transmit.

  A third feature of the present invention is a radio base station, which is configured to notify a predetermined timing to a relay node when setting up a connection with the relay node; And a scheduling unit configured to perform scheduling so as to transmit a downlink signal to the relay node at the predetermined timing.

  A fourth feature of the present invention is a radio base station, and when setting up a connection with a relay node, an acquisition unit configured to acquire a predetermined timing from the relay node; And a scheduling unit configured to perform scheduling so as to transmit a downlink signal to the relay node at a predetermined timing.

  A fifth feature of the present invention is a relay node, and when setting up a connection with a radio base station, an acquisition unit configured to acquire a predetermined timing from the radio base station; And a scheduling unit configured to perform scheduling so as to transmit a downlink signal at a timing other than the predetermined timing.

  A sixth feature of the present invention is a relay node that is configured to notify a predetermined timing to a radio base station when setting up a connection with the radio base station. And a scheduling unit configured to perform scheduling so as to transmit a downlink signal at a timing other than the predetermined timing.

  As described above, according to the present invention, mobile communication capable of reducing the interference to the receiver of the relay node itself caused by simultaneous transmission / reception processing in the Un radio bearer and transmission / reception processing in the Uu radio bearer. A method, a radio base station, and a relay node can be provided.

1 is an overall configuration diagram of a mobile communication system according to a first embodiment of the present invention. FIG. 3 is a functional block diagram of a radio base station according to the first embodiment of the present invention. It is a figure which shows an example of the format of "RRC Connection Request" in the mobile communication system which concerns on the 1st Embodiment of this invention. FIG. 3 is a diagram illustrating an example of a format of “RRC Connection Reconfiguration” in the mobile communication system according to the first embodiment of the present invention. It is a figure for demonstrating an example of the method of notifying a sub-frame pattern in the mobile communication system which concerns on the 1st Embodiment of this invention. FIG. 3 is a functional block diagram of a relay node according to the first embodiment of the present invention. FIG. 3 is a sequence diagram showing an operation of the mobile communication system according to the first embodiment of the present invention. It is a sequence diagram which shows operation | movement of the mobile communication system which concerns on the modification 1 of the 1st Embodiment of this invention. It is a functional block diagram of the relay node which concerns on the 2nd Embodiment of this invention. It is a figure which shows an example of a format of "RRC RN (UE) Capability Information" in the mobile communication system which concerns on the 2nd Embodiment of this invention. It is a functional block diagram of the radio base station which concerns on the 2nd Embodiment of this invention. It is a sequence diagram which shows operation | movement of the mobile communication system which concerns on the 2nd Embodiment of this invention. It is a sequence diagram which shows operation | movement of the mobile communication system which concerns on the modification 1 of the 2nd Embodiment of this invention.

(Configuration of mobile communication system according to the 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 FIG. 1 to FIG.

  As shown in FIG. 1, the mobile communication system according to the present embodiment is an LTE-Advanced mobile communication system, and includes core nodes (for example, a gateway device S-GW and an exchange MME) in a core network node. , Radio base station DeNB, relay node RN and the like.

  Here, in the example of FIG. 1, a Uu radio bearer is set between the radio base station DeNB and the mobile station UE, and an Un radio bearer is set between the radio base station DeNB and the relay node RN. The Uu radio bearer is set between the relay node RN and the mobile station UE.

  In addition, it is assumed that SFN (System Frame Number) synchronization is established between the radio base station DeNB and the relay node RN. That is, the relay node RN is configured to synchronize with the radio base station DeNB at the SFN level based on the SFN included in the broadcast information transmitted by the radio base station DeNB.

  In addition, when the SFN synchronization is not established between the radio base station DeNB and the relay node RN, the radio base station DeNB has the SFN of the radio frame transmitted by itself and the SFN of the radio frame transmitted by the relay node RN. It is configured to grasp how many frames are shifted at the same time.

  Further, the radio base station DeNB and the relay node RN are configured to transmit an uplink signal and a downlink signal by a time division multiplexing method.

  As illustrated in FIG. 2, the radio base station DeNB includes a reception unit 11, a transmission unit 12, a scheduling unit 13, and a determination unit 14.

  The receiving unit 11 receives an uplink signal transmitted from the relay node RN via the Un radio bearer, an uplink signal transmitted from the mobile station UE via the Uu radio bearer, and a downlink signal transmitted from the core node CN. It is configured as follows.

  For example, the receiving unit 11 is configured to receive “RRC Connection Request” and the like transmitted from the relay node RN in the procedure for setting up the RRC connection between the radio base station DeNB and the relay node RN.

  The transmission unit 12 transmits a downlink signal to the relay node RN via the Un radio bearer, transmits a downlink signal to the mobile station UE via the Uu radio bearer, and transmits an uplink signal to the core node CN. Is configured to do.

  In addition, when setting up an RRC connection with the relay node RN, the transmission unit 12 notifies the relay node RN of the transmission timing (predetermined timing) of an MBSFN (Multicast Broadcast Single Frequency Network) subframe. It is configured.

  Here, the MBSFN subframe is a subframe used in MBSFN communication. In this specification, the MBSFN subframe also includes an MBSFN subframe that is defined so as not to transmit a control signal OFDM symbol called a “Blank subframe” in a 3GPP meeting.

  Further, the transmission unit 12 is configured to notify the relay node RN of the transmission timing of the MBSFN subframe when the transmission source of the “RRC Connection Request” received by the reception unit 11 is the relay node RN. It may be.

  FIG. 3 shows an example of an existing “RRC Connection Request” format.

  For example, a bit (flag) indicating either “relay node RN” or “mobile station UE” is provided in “spare” (X) in the information element “RRCConnectionRequest-r8” in the “RRC Connection Request”. It may be.

  Alternatively, a bit (flag) indicating either “relay node RN” or “mobile station UE” is provided in “spare3” (Y) in the information element “EstablishmentCause” in the “RRC Connection Request”. May be.

  Here, when the flag provided in the existing “RRC Connection Request” indicates “relay node RN”, the transmission unit 12 indicates that the transmission source of the “RRC Connection Request” received by the reception unit 11 is the relay node RN. It may be configured to determine that

  Moreover, the transmission part 12 may be comprised so that the transmission timing of a MBSFN sub-frame may be notified with respect to the relay node RN by "RRC Connection Reconfiguration" transmitted in the setting procedure of the existing RRC connection.

  For example, as illustrated in FIG. 4, the transmission unit 12 sets “MBSFN subframe allocation pattern” indicating the transmission timing of the MBSFN subframe in “critical ExtensionsFuture” (Z) in the information element “criticalExtensions” in “RRC Connection Reconfiguration”. (See FIG. 5).

  The determination unit 14 is configured to determine the transmission timing of the MBSFN subframe to be notified to the relay node RN.

  For example, the determination unit 14 determines the transmission timing of the MBSFN subframe to be notified to the relay node RN in consideration of the number of relay nodes RN and mobile stations UE under the radio base station DeNB and the amount of traffic. It is configured.

  The scheduling unit 13 is configured to perform scheduling related to the relay node RN and the mobile station UE under the radio base station DeNB.

  Specifically, the scheduling unit 13 is configured to perform scheduling so as to transmit a downlink signal to the relay node RN at the transmission timing of the MBSFN subframe.

  As illustrated in FIG. 6, the relay node RN includes a reception unit 21, a scheduling unit 22, and a transmission unit 24.

  The receiving unit 11 is configured to receive a downlink signal transmitted from the radio base station DeNB via the Un radio bearer and an uplink signal transmitted from the mobile station UE via the Uu radio bearer.

  In addition, the reception unit 21 is configured to acquire the transmission timing of the MBSFN subframe from the radio base station DeNB when setting an RRC connection with the radio base station DeNB.

  For example, the receiving unit 21 may be configured to acquire the transmission timing of the MBSFN subframe from “RRC Connection Reconfiguration” transmitted in the existing RRC connection setting procedure.

  The scheduling unit 22 is configured to perform scheduling related to the mobile station UE under the relay node RN.

  Specifically, the scheduling unit 22 is configured to perform scheduling so as to transmit a downlink signal at a timing other than the transmission timing of the MBSFN subframe.

  The transmission unit 24 is configured to transmit an uplink signal to the radio base station DeNB via the Un radio bearer and to transmit a downlink signal to the mobile station UE via the Uu radio bearer.

  In addition, the transmission unit 24 is configured to transmit “RRC Connection Request” including information indicating that it has been transmitted by the relay node RN to the radio base station DeNB in the procedure of setting the RRC connection.

(Operation of the mobile communication system according to the first embodiment of the present invention)
With reference to FIG. 7, the operation of the mobile communication system according to the first embodiment of the present invention will be described.

  As illustrated in FIG. 7, in step S1001, the relay node RN transmits “RRC Connection Request” to the radio base station DeNB at the time of activation.

  In Step S1002, the radio base station DeNB determines that the “RRC Connection Request” is transmitted from the relay node RN based on the flag set in the “RRC Connection Request”, and the relay node RN. In response, “RRC Connection Setup” is transmitted.

  In Step S1003, the relay node RN transmits “RRC Connection Setup Complete” including “Attach Request” to the radio base station DeNB.

  In step S1004, the radio base station DeNB transmits “Initial UE Message” including “Attach Request” to the core node CN.

  In step S1005, after the “Authentication / Security process” is completed between the relay node RN and the core node CN, in step S1006, the core node CN makes a “Initial Context” including “Attach Accept” to the radio base station DeNB. Send a “Setup Request”.

  In step S1007, the radio base station DeNB transmits “RRC RN (UE) Capability Enquiry” to the relay node RN.

  In Step S1008, the relay node RN transmits “RRC RN (UE) Capability Information” to the radio base station DeNB.

  In step S1009, the radio base station DeNB transmits “(UE) Capability Info Indication” to the core node CN.

  The radio base station DeNB transmits “Security Mode Command” to the relay node RN in Step S1010, and transmits “RRC Connection Reconfiguration” including “Attach Accept” in Step S1011.

  Here, the radio base station DeNB notifies the relay node RN of the transmission timing of the above MBSFN subframe by “RRC Connection Reconfiguration”.

  In step S1012, the relay node RN transmits “Security Mode Complete” to the radio base station DeNB, and in step S1013, transmits “RRC Connection Reconfiguration Complete”.

  In step S1014, the radio base station DeNB transmits “Initial Context Setup Response” to the core node CN.

  In step S1015, the relay node RN transmits “Attach Complete” to the core node CN.

(Operations and effects of the mobile communication system according to the first embodiment of the present invention)
According to the mobile communication system according to the first embodiment of the present invention, the resources in the relay node RN are controlled in consideration of the number of relay nodes RN and mobile stations UE under the radio base station DeNB and the traffic volume. Can do.

(Modification 1)
With reference to FIG. 8, a mobile communication system according to Modification 1 of the first embodiment of the present invention will be described. Hereinafter, the mobile communication system according to the first modification will be described by focusing on the differences from the above-described mobile communication system according to the first embodiment of the present invention.

  In the mobile communication system according to the first modification example, the transmission unit 12 of the radio base station DeNB transmits the MBSFN subframe transmission timing to the relay node RN by “Un Setup Response” instead of “RRC Connection Reconfiguration”. May be configured to notify.

  The “Un Setup Response” is not defined in the existing RRC connection setup procedure, but is a signal used in a procedure newly defined between the radio base station DeNB and the relay node RN.

  Further, the reception unit 21 of the relay node RN may be configured to acquire the transmission timing of the MBSFN subframe from the “Un Setup Response” described above.

  Hereinafter, the operation of the mobile communication system according to the first modification will be described with reference to FIG.

  As shown in FIG. 8, the operations in steps S2001 to S2015 are the same as the operations in steps S1001 to S1015 shown in FIG. However, in step S2011, the radio base station DeNB does not notify the relay node RN of the transmission timing of the MBSFN subframe described above by “RRC Connection Reconfiguration”.

  In step S2016, the relay node RN sets, for the radio base station DeNB, an Un radio bearer necessary for the relay node RN to operate as a radio relay base station between the relay node RN and the radio base station DeNB. “Un Setup Request” is transmitted to request this.

  In step S2017, the radio base station DeNB transmits “Un Setup Response” to the relay node RN.

  Here, the radio base station DeNB notifies the relay node RN of the transmission timing of the MBSFN subframe described above by “Un Setup Response”.

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

  The first feature of the present embodiment is a mobile communication method, and when the RRC connection (connection) is set between the radio base station DeNB and the relay node RN, the radio base station DeNB is set to the relay node RN. On the other hand, the step A of notifying the transmission timing (predetermined timing) of the MBSFN subframe, and the step of performing scheduling so that the radio base station DeNB transmits a downlink signal to the relay node RN at the transmission timing of the MBSFN subframe. The gist is that B and the relay node RN have a process C that performs scheduling so as to transmit a downlink signal at a timing other than the transmission timing of the MBSFN subframe.

  In the first feature of the present embodiment, in step A, the radio base station DeNB sets the transmission timing of the MBSFN subframe to the relay node RN by “RRC Connection Reconfiguration” transmitted in the RRC connection setting procedure. You may be notified.

  The second feature of the present embodiment is the radio base station DeNB, which notifies the relay node RN of the transmission timing of the MBSFN subframe when setting the RRC connection with the relay node RN. And a scheduling unit 13 configured to perform scheduling so as to transmit a downlink signal to the relay node RN at the transmission timing of the MBSFN subframe. To do.

  In the second feature of the present embodiment, the receiving unit 11 is configured to receive an “RRC Connection Request” transmitted in the RRC connection setting procedure. In the RRC connection setting procedure, the transmitting unit 12 When the transmission source of the “RRC Connection Request” received by the receiving unit 11 is the relay node RN, the “RRC Connection Reconfiguration” notifies the relay node RN of the transmission timing of the MBSFN subframe by “RRC Connection Reconfiguration”. It may be configured.

  A third feature of the present embodiment is a relay node RN, which acquires the transmission timing of the MBSFN subframe from the radio base station DeNB when setting up an RRC connection with the radio base station DeNB. The gist of the invention is that it includes a receiving unit 21 configured and a scheduling unit 22 configured to perform scheduling so as to transmit a downlink signal at a timing other than the transmission timing of the MBSFN subframe.

  In the third feature of the present embodiment, the reception unit 21 may be configured to acquire the transmission timing of the MBSFN subframe from “RRC Connection Reconfiguration” transmitted in the RRC connection setting procedure.

  In the third feature of the present embodiment, a transmission unit 24 configured to transmit “RRC Connection Request” including information indicating transmission by the relay node RN in the RRC connection setting procedure is provided. May be.

(Mobile communication system according to the second embodiment of the present invention)
A mobile communication system according to the second embodiment of the present invention will be described with reference to FIG. 9 to FIG. Hereinafter, the mobile communication system according to the second embodiment of the present invention will be described by focusing on differences from the above-described mobile communication system according to the first embodiment of the present invention.

  The mobile communication system according to the second embodiment of the present invention is configured such that the transmission timing of the above MBSFN subframe is determined not by the radio base station DeNB but by the relay node RN.

  As illustrated in FIG. 9, the relay node RN includes a reception unit 21, a scheduling unit 22, a determination unit 23, and a transmission unit 24.

  The determination unit 23 is configured to determine the transmission timing of the MBSFN subframe described above.

  For example, the determination unit 23 may use the timing stored in advance as station data in the relay node RN as the transmission timing of the above-described MBSFN subframe or the timing acquired from an OAM (Operation & Maintenance) server as described above. It may be the transmission timing of the MBSFN subframe.

  The transmitter 24 is configured to notify the radio base station DeNB of the transmission timing of the MBSFN subframe when setting up an RRC connection with the radio base station DeNB.

  Specifically, the transmission unit 24 notifies the relay node RN of the transmission timing of the MBSFN subframe by “RRC RN (UE) Capability Information” transmitted in the existing RRC connection setup procedure. It may be configured.

  For example, as illustrated in FIG. 10, the transmission unit 24 transmits the MBSFN subframe to “ue-CapabilityRAT-ContainerList” (A) in the information element “UECapabilityInformation-r8” in “RRC RN (UE) Capability Information”. An “MBSFN subframe allocation pattern (see FIG. 5)” indicating transmission timing may be set.

  As illustrated in FIG. 11, the radio base station DeNB includes a reception unit 11, a transmission unit 12, and a scheduling unit 13.

  The receiving unit 11 is configured to acquire the transmission timing of the MBSFN subframe from the relay node RN when setting up the RRC connection with the relay node RN.

  Specifically, the reception unit 11 may be configured to acquire the transmission timing of the MBSFN subframe from “RRC RN (UE) Capability Information” transmitted in the RRC connection setting procedure.

  Hereinafter, the operation of the mobile communication system according to the second embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 12, the operations in steps S3001 to S2015 are the same as the operations in steps S1001 to S1015 shown in FIG.

  However, in step S2011, the radio base station DeNB does not notify the relay node RN of the transmission timing of the MBSFN subframe described above by “RRC Connection Reconfiguration”.

  Instead, in step S3008, the relay node RN notifies the relay node RN of the transmission timing of the MBSFN subframe by “RRC RN (UE) Capability Information”.

  According to the mobile communication system according to the second embodiment of the present invention, it is possible to reduce the occurrence of interference in the relay node RN by simple control.

(Modification 1)
With reference to FIG. 13, a mobile communication system according to Modification 1 of the second embodiment of the present invention will be described. Hereinafter, the mobile communication system according to the first modification will be described by focusing on the differences from the mobile communication system according to the second embodiment of the present invention described above.

  In the mobile communication system according to the first modification, the transmission unit 24 of the relay node RN performs MBSFN on the radio base station DeNB by “Un RN Configuration Indication” instead of “RRC RN (UE) Capability Information”. You may be comprised so that the transmission timing of a sub-frame may be notified.

  “Un RN Configuration Indication” is not defined in the existing RRC connection setting procedure, but is a signal used in a procedure newly defined between the radio base station DeNB and the relay node RN.

  Further, the reception unit 11 of the radio base station DeNB may be configured to acquire the transmission timing of the MBSFN subframe from the “Un RN Configuration Indication” described above.

  Hereinafter, the operation of the mobile communication system according to the first modification will be described with reference to FIG.

  As shown in FIG. 13, the operations in steps S4001 to S2015 are the same as the operations in steps S3001 to S3015 shown in FIG. However, in step S4008, the relay node RN does not notify the transmission timing of the above MBSFN subframe to the radio base station DeNB by “RRC RN (UE) Capability Information”.

  In step S4016, the relay node RN notifies the radio base station DeNB of “Un RN Configuration Indication” that notifies the configuration of the Un radio bearer as a radio relay base station between the relay node RN and the radio base station DeNB. Send.

  Here, the relay node RN notifies the radio base station DeNB of the transmission timing of the MBSFN subframe described above by “Un RN Configuration Indication”.

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

  The first feature of the present embodiment is a mobile communication method, and when the RRC connection is set between the radio base station DeNB and the relay node RN, the relay node RN Step A for notifying the transmission timing of the MBSFN subframe, Step B for performing scheduling so that the radio base station DeNB transmits a downlink signal to the relay node RN at the transmission timing of the MBSFN subframe, and the relay node RN And a process C for performing scheduling so as to transmit the downlink signal at a timing other than the transmission timing of the MBSFN subframe.

  In the first feature of the present embodiment, in step A, the relay node RN transmits the MBSFN subframe to the radio base station DeNB by “RRC RN (UE) Capability Information” transmitted in the RRC connection setup procedure. The transmission timing may be notified.

  The second feature of the present embodiment is the radio base station DeNB, which is configured to acquire the transmission timing of the MBSFN subframe from the relay node RN when setting the RRC connection with the relay node RN. And a scheduling unit 13 configured to perform scheduling so as to transmit a downlink signal to the relay node RN at the transmission timing of the MBSFN subframe.

  In the second feature of the present embodiment, the receiving unit 11 is configured to acquire the transmission timing of the MBSFN subframe from “RRC RN (UE) Capability Information” transmitted in the RRC connection setting procedure. Also good.

  The third feature of the present embodiment is the relay node RN, which notifies the radio base station DeNB of the transmission timing of the MBSFN subframe when an RRC connection is established with the radio base station DeNB. The gist of the present invention is that the transmission unit 24 configured as described above and the scheduling unit 22 configured to perform scheduling so as to transmit a downlink signal at a timing other than the transmission timing of the MBSFN subframe.

  In the third feature of the present embodiment, in the RRC connection setup procedure, the transmission unit 24 notifies the radio base station DeNB of the transmission timing of the MBSFN subframe by “RRC RN (UE) Capability Information”. It may be configured as follows.

  The operations of the radio base station DeNB, the relay node RN, the core node CN, and the mobile station UE described above may be implemented by hardware, may be implemented by a software module executed by a processor, It may be implemented by a combination.

  The software module includes a RAM (Random Access Memory), a flash memory, a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electronically Erasable and Programmable ROM, a hard disk, a registerable ROM, a hard disk). Alternatively, it may be provided in a storage medium of an arbitrary format such as a CD-ROM.

  Such a storage medium is connected to the processor so that the processor can read and write information from and to the storage medium. Further, such a storage medium may be integrated in the processor. Such a storage medium and processor may be provided in the ASIC. Such an ASIC may be provided in the radio base station DeNB, the relay node RN, the core node CN, or the mobile station UE. Further, the storage medium and the processor may be provided in the radio base station DeNB, the relay node RN, the core node CN, and the mobile station UE as discrete components.

  Although the present invention has been described in detail using the above-described embodiment, it is obvious for those skilled in the art that the present invention is not limited to the embodiment described in the present specification. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

DeNB ... Radio base station 11 ... Receiving unit 12 ... Transmitting unit 13 ... Scheduling unit 14 ... Determining unit RN ... Relay node 21 ... Receiving unit 22 ... Scheduling unit 23 ... Determining unit 24 ... Transmitting unit

Claims (1)

When the connection is established between the radio base station and the relay node, the radio base station notifies the relay node of a predetermined timing, and
A step B in which the radio base station performs scheduling so as to transmit a downlink signal to the relay node at the predetermined timing; and
A mobile communication method comprising: a step of performing scheduling so that the relay node transmits a downlink signal at a timing other than the predetermined timing.