JP2011124930A - Mobile communication system and relay node - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow a handover of a mobile station from a cell subordinate to a relay node connected to a wireless base station to a cell subordinate to another relay node connected to the relay node. <P>SOLUTION: A mobile communication system is constituted so that an X2 interface is not set and an S1 interface is set between the wireless base station DeNB#2 and the relay node RN#3, and an X2 interface is not set and an S1 interface is set between a relay node RN#3 and a relay node RN#4, wherein the relay node RN#3 terminates a control signal for a handover procedure received from the relay node RN#4 through the S1 interface, the handover procedure being for a handover of the mobile station UE between a cell subordinate to the relay node RN#3 and a cell subordinate to the relay node RN#4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a mobile communication system and a relay node.

  In an LTE-Advanced mobile communication system that is a successor of the LTE (Long Term Evolution) system, a relay node RN (Relay Node) may be provided between the radio base station DeNB (Doner-eNB) and the mobile station UE. It is configured to be able to.

3GPP TR36.806 (V0.1. 1), “Evolved Universal Terrestrial Radio Access (E-UTRA); Relay architectures for E-UTRA (LTE-Advanced), Mon. 9” (Release 9).

  However, in such a mobile communication system, the handover procedure of the mobile station UE from the cell under the relay node RN connected to the radio base station DeNB to the cell under another relay node connected to the relay node RN However, there is a problem that it is not stipulated specifically as to how it should be realized.

  Further, in such a mobile communication system, the handover procedure of the mobile station UE from the cell under the radio base station DeNB to the cell under another relay node connected to the relay node RN connected to the radio base station DeNB, There was a problem that it was not specifically defined how to be realized.

  Therefore, the present invention has been made in view of the above problems, and a mobile station for a cell under a relay node connected to the relay node from a cell under the relay node connected to the radio base station. Communication system and relay node enabling handover of a mobile station to a cell under another relay node connected to a relay node connected to the radio base station from a cell under the radio base station The purpose is to provide.

  A first feature of the present invention is a mobile comprising a radio base station, a first relay node connected to the radio base station, and a second relay node connected to the first relay node In the communication system, an X2 interface is not set and an S1 interface is set between the radio base station and the first relay node, and the first relay node, the second relay node, In the handover procedure between the cell under the second relay node and the cell under the first relay node of the mobile station, in which the X2 interface is not set and the S1 interface is set The first relay node terminates the control signal for the handover procedure received from the second relay node via the S1 interface. Made is the gist that are.

  According to a second aspect of the present invention, there is provided a mobile comprising a radio base station, a first relay node connected to the radio base station, and a second relay node connected to the first relay node. In the communication system, an X2 interface is not set and an S1 interface is set between the radio base station and the first relay node, and the first relay node, the second relay node, In the handover procedure between the cell under the radio base station of the mobile station and the cell under the second relay node in the mobile station, the X2 interface is not set and the S1 interface is set. 1 relay node sends the control signal for the handover procedure received from the second relay node via the S1 interface to the radio base station. It is configured to transfer the control signal for the handover procedure, which is transferred through one interface and received from the radio base station through the S1 interface, to the second relay node through the S1 interface. This is the gist.

  A third feature of the present invention is a relay node connected to a radio base station and another relay node via the S1 interface instead of the X2 interface, and control for the handover procedure received via the S1 interface A determination unit configured to determine a destination of the signal, and a reception configured to terminate the control signal for the handover procedure when the destination of the control signal for the handover procedure is the relay node And when the destination of the control signal for the handover procedure is the other relay node or the radio base station, the control signal for the handover procedure is sent to the other relay node or the radio base station. And a transmitter configured to transfer the data via an interface.

  As described above, according to the present invention, a handover of a mobile station from a cell under a relay node connected to a radio base station to a cell under another relay node connected to the relay node, and radio A mobile communication system and a relay node that enable handover of a mobile station from a cell under a base station to a cell under another relay node connected to a relay node connected to the radio base station 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 C-plane protocol stack diagram in the mobile communication system according to the first embodiment of the present invention. FIG. 2 is a U-plane protocol stack diagram in the mobile communication system according to the first embodiment of the present invention. FIG. 3 is a functional block diagram of a relay node RN according to the first embodiment of the present invention. FIG. 6 is a sequence diagram illustrating an operation in which the mobile station UE performs handover from the relay node RN # 4 to the relay node RN # 3 in the mobile communication system according to the first embodiment of the present invention. FIG. 7 is a sequence diagram illustrating an operation in which the mobile station UE performs handover from the relay node RN # 3 to the relay node RN # 4 in the mobile communication system according to the first embodiment of the present invention. FIG. 6 is a sequence diagram illustrating an operation in which the mobile station UE performs handover from the relay node RN # 4 to the radio base station DeNB # 2 in the mobile communication system according to the first embodiment of the present invention. FIG. 6 is a sequence diagram illustrating an operation in which the mobile station UE performs a handover from the radio base station DeNB # 2 to the relay node RN # 4 in the mobile communication system according to the first embodiment of the present invention. It is a flowchart which shows operation | movement of the relay node RN which concerns on the 1st Embodiment of this invention.

(Mobile communication system according to the first embodiment of the present invention)
With reference to FIG. 1 thru | or FIG. 9, the mobile communication system which concerns on the 1st Embodiment of this invention is demonstrated.

  The mobile communication system according to the present embodiment is an LTE-Advanced mobile communication system, and as shown in FIG. 1, an exchange MME, a plurality of radio base stations eNB / DeNB # 1 / DeNB # 2, A plurality of relay nodes RN # 1 / RN # 2 / RN # 3 / RN # 4 and a mobile station UE are provided.

  In the present embodiment, the handover procedure of the mobile station UE from the cell under the relay node RN # 3 connected to the radio base station DeNB # 2 to the cell under the relay node RN # 4 connected to the relay node RN # 3 , Handover procedure of mobile station UE from cell under relay node RN # 4 to cell under relay node RN # 3, handover of mobile station UE from cell under relay node RN # 4 to cell under radio base station DeNB # 2 A procedure and a mobile communication system for realizing a handover procedure of the mobile station UE from a cell under the radio base station DeNB # 2 to a cell under the relay node RN # 4 will be described.

  Here, as shown in FIG. 1, between the radio base station DeNB # 2 and the relay node RN # 3, the X2 interface is not set, the S1 interface is set, and the relay node RN # 3 The X2 interface is not set with the relay node RN # 4, and the S1 interface is set.

  FIG. 2 shows a C-plane protocol stack in the mobile communication system according to the present embodiment, and FIG. 3 shows a U-plane protocol stack in the mobile communication system according to the present embodiment.

  As shown in FIG. 2, the mobile station UE has a physical (PHY) layer function, a MAC (Media Access Control) layer function, an RLC (Radio Link Control) layer function, a PDCP ( It has a Packet Data Convergence Protocol (Layer) layer function and an RRC (Radio Resource Control) layer function.

  The relay node RN has a physical (PHY) layer function, a MAC layer function, an RLC layer function, a PDCP layer function, and an RRC layer function on the mobile station UE side as a C-plane protocol function. Yes.

  Further, the relay node RN has a physical (PHY) layer function, a MAC layer function, an RLC layer function, a PDCP layer function, and an IP (Internet Protocol) on the radio base station DeNB side as a C-plane protocol function. It includes a layer function, an SCTP (Stream Control Transmission Protocol) layer function, and an S1AP (S1 Application) layer function.

  The radio base station DeNB has a physical (PHY) layer function, a MAC layer function, an RLC layer function, a PDCP layer function, an IP layer function, an SCTP layer on the relay node RN side as a C-plane protocol function. And a S1AP layer function.

  In addition, the radio base station DeNB has, as a C-plane protocol function, an NWL1 (Network Layer 1) function, an NWL2 (Network Layer 2) function, an IP layer function, and a switching management MME (Mobility Management Entity) side. It has an SCTP layer function and an S1AP layer function.

  The switching center MME has an NWL1 function, an NWL2 function, an IP layer function, an SCTP layer function, and an S1AP layer function as C-plane protocol functions.

  Here, as shown in FIG. 2, the S1 interface protocol is terminated between the S1AP layer function of the relay node RN and the S1AP layer function of the radio base station DeNB, and the S1AP layer function of the radio base station DeNB and The S1 interface protocol may be terminated with the S1AP layer function of the switching center MME.

  Further, as shown in FIG. 3, the mobile station UE has a physical (PHY) layer function, a MAC layer function, an RLC layer function, a PDCP layer function, and an RRC layer function as U-plane protocol functions. It has.

  The relay node RN has a physical (PHY) layer function, a MAC layer function, an RLC layer function, a PDCP layer function, and an RRC layer function on the mobile station UE side as a U-plane protocol function. Yes.

  Further, the relay node RN has a physical (PHY) layer function, a MAC layer function, an RLC layer function, a PDCP layer function, an IP layer function, and a U-plane protocol function on the radio base station DeNB side. It has a UDP (User Datagram Protocol) layer function and a GTP (GPRS Tunneling Protocol) -U layer function.

  The radio base station DeNB has a physical (PHY) layer function, a MAC layer function, an RLC layer function, a PDCP layer function, an IP layer function, and a UDP layer on the relay node RN side as a U-plane protocol function. And a GTP-U layer function.

  In addition, the radio base station DeNB has an NWL1 function, an NWL2 function, an IP layer function, a UDP layer function, and a GTP-U layer function on the exchange MME side as a U-plane protocol function. Yes.

  The exchange MME includes an NWL1 function, an NWL2 function, an IP layer function, a UDP layer function, and a GTP-U layer function as U-plane protocol functions.

  As illustrated in FIG. 4, the relay node RN (for example, the relay node RN # 3 in the present embodiment) includes a reception unit 11, a determination unit 12, and a transmission unit 13.

  The receiving unit 11 is configured to receive a control signal for handover procedure (for example, “(S1) HO Required” or the like) from the radio base station DeNB or another relay node RN via the S1 interface. .

  The transmission unit 13 transmits a control signal for handover procedure received by the reception unit 11 to the radio base station DeNB or another relay node RN via the S1 interface (for example, “(S1) HO Required”). Configured to transfer.

  The determination unit 12 is configured to determine the destination of the control signal for the handover procedure received by the reception unit 11.

  Here, when it is determined that the destination of the control signal for the handover procedure is the relay node RN itself, the receiving unit 11 is configured to terminate the control signal for the handover procedure.

  On the other hand, when it is determined that the destination of the control signal for the handover procedure is another relay node RN or the radio base station DeNB, the transmission unit 13 sends the control signal for the handover procedure to another relay node RN or the radio base station It is configured to transfer to the station DeNB via the S1 interface.

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

  First, referring to FIG. 5, in the mobile communication system according to the present embodiment, the handover procedure from the cell # 4 under the relay node RN # 4 of the mobile station UE to the cell # 3 under the relay node RN # 3. The operation when performing the above will be described.

  As illustrated in FIG. 5, in step S1001, the relay node RN # 4 transmits “Measurement Control” to the mobile station UE being connected in the cell # 4.

  In Step S1002, the mobile station UE transmits “Measurement Report” to the relay node RN # 4 at a predetermined timing based on the “Measurement Control” described above.

  When the relay node RN # 4 determines to start the handover procedure from the cell # 4 to the cell # 3 of the mobile station UE in step S1003, the relay node RN # 4 instructs the relay node RN # 3 to “(S1 ) HO Required ”.

  In step S1005, the relay node RN # 3 determines that the destination of the received “(S1) HO Required” is the relay node RN # 3 itself, that is, the “(S1) HO Required” is the relay node RN #. 3 is determined to be a control signal for the handover procedure for cell # 3 under its control, terminates such “(S1) HO Required”, and transmits “(S1) HO Command” to relay node RN # 4. .

  In step S1006, the relay node RN # 4 determines that the destination of the received “(S1) HO Command” is the relay node RN # 4 itself, terminates the “(S1) HO Command”, and the mobile station UE "RRC Connection Reconfiguration" is transmitted, and in step S1007, "(S1) eNB Status Transfer" is transmitted to the relay node RN # 3.

  In step S1008, the mobile station UE performs a detach process from the cell # 4 and performs a synchronization process with the cell # 3.

  In step S1009, the mobile station UE transmits “Random Access Preamble” to the relay node RN # 3. In step S1010, the relay node RN # 3 transmits radio resources in the uplink to the mobile station UE. Is transmitted, and “TA (Timing Adjustment)” for the mobile station UE is transmitted. In Step S1011, the mobile station UE transmits “RRC Connection Reconfiguration Complete” to the relay node RN # 3.

  In step S1012, the relay node RN # 3 transmits “(X2) UE Context Release” to the relay node RN # 4.

  Before and after the handover procedure described above, the S1 connection for the mobile station UE set between the relay node RN # 3 and the radio base station DeNB # 2, and the exchange MME and the radio base station DeNB # 2 There is no change in the S1 connection for the mobile station UE set in between.

  Second, referring to FIG. 6, in the mobile communication system according to the present embodiment, the handover procedure from the cell # 3 under the relay node RN # 3 of the mobile station UE to the cell # 4 under the relay node RN # 4 The operation when performing the above will be described.

  As illustrated in FIG. 6, in step S2001, the relay node RN # 3 transmits “Measurement Control” to the mobile station UE connected in the cell # 3.

  In step S2002, the mobile station UE transmits “Measurement Report” to the relay node RN # 3 at a predetermined timing based on the above “Measurement Control”.

  When the relay node RN # 3 determines to start the handover procedure from the cell # 3 to the cell # 4 of the mobile station UE in step S2003, the relay node RN # 3 instructs the relay node RN # 4 to “(S1 ) HO Request ".

  In step S2005, the relay node RN # 4 determines that the destination of the received “(S1) HO Request” is the relay node RN # 4 itself, that is, the “(S1) HO Request” is the relay node RN #. 4 is determined to be a control signal for the handover procedure for cell # 4 under the control, terminates the “(S1) HO Request”, and transmits “(S1) HO Command” to the relay node RN # 3. .

  In step S2006, the relay node RN # 3 determines that the destination of the received “(S1) HO Command” is the relay node RN # 3 itself, terminates the “(S1) HO Command”, and the mobile station UE "RRC Connection Reconfiguration" is transmitted, and in step S2007, "(S1) MME Status Transfer" is transmitted to the relay node RN # 4.

  Here, the relay node RN # 4 determines that the destination of the received “(S1) MME Status Transfer” is the relay node RN # 4 itself, and terminates the “(S1) MME Status Transfer”.

  In step S2008, the mobile station UE performs a detach process from the cell # 3 and performs a synchronization process with the cell # 4.

  In Step S2009, the mobile station UE transmits “Random Access Preamble to the relay node RN # 4. In Step S2010, the relay node RN # 4 transmits radio resources in the uplink to the mobile station UE. In step S2011, the mobile station UE transmits “RRC Connection Reconfiguration Complete” to the relay node RN # 4.

  In step S2012, the relay node RN # 4 transmits “(S1) Path Switch Request” to the relay node RN # 3.

  In step S2013, the relay node RN # 3 determines that the destination of the received “(S1) Path Switch Request” is the relay node RN # 3 itself, terminates the “(S1) Path Switch Request”, and relays the relay. “(S1) Path Switch Request ACK” is transmitted to node RN # 4.

  In step S2014, the relay node RN # 4 transmits “(S1) UE Context Release” to the relay node RN # 3.

  Here, the relay node RN # 3 determines that the destination of the received “(S1) UE Context Release” is the relay node RN # 3 itself, and terminates the “(S1) UE Context Release”.

  Before and after the handover procedure described above, the S1 connection for the mobile station UE set between the relay node RN # 3 and the radio base station DeNB # 2, and the exchange MME and the radio base station DeNB # 2 There is no change in the S1 connection for the mobile station UE set in between.

  Third, referring to FIG. 7, in the mobile communication system according to the present embodiment, the handover from the cell # 4 under the relay node RN # 4 of the mobile station UE to the cell # 2 under the radio base station DeNB # 2 The operation when performing the procedure will be described.

  As illustrated in FIG. 7, in step S3001, the relay node RN # 4 transmits “Measurement Control” to the mobile station UE connected in the cell # 4.

  In step S3002, the mobile station UE transmits “Measurement Report” to the relay node RN # 4 at a predetermined timing based on the above “Measurement Control”.

  When the relay node RN # 4 determines to start the handover procedure from the cell # 4 to the cell # 2 of the mobile station UE in step S3003, the relay node RN # 4 instructs the relay node RN # 3 to “(S1 ) HO Required ”.

  In step S3005, the relay node RN # 3 determines that the destination of the received “(S1) HO Required” is the radio base station DeNB # 2, that is, the “(S1) HO Required” is the radio base station DeNB. The control signal is determined to be a control signal for the handover procedure for cell # 2 under # 2, and the “(S1) HO Required” is transferred to the radio base station DeNB # 2.

  In step S3006, the radio base station DeNB # 2 determines that the destination of the received “(S1) HO Required” is the radio base station DeNB # 2 itself, that is, the “(S1) HO Required” is the radio base station. It determines that it is a control signal for the handover procedure for the cell # 2 under the station DeNB # 2, terminates the “(S1) HO Required”, and sends “(S1) HO Command” to the relay node RN # 3. Send.

  In step S3007, the relay node RN # 3 determines that the destination of the received “(S1) HO Command” is the relay node RN # 4, and the relay node RN # 4 receives the “(S1) HO Command”. ".

  In step S3008, the relay node RN # 4 transmits “RRC Connection Reconfiguration” to the mobile station UE, and in step S3009, transmits “(S1) eNB Status Transfer” to the relay node RN # 3. To do.

  In step S3010, the relay node RN # 3 determines that the destination of the received “(S1) eNB Status Transfer” is the radio base station DeNB # 2, and the radio base station DeNB # 2 receives “(S1 ) ENB Status Transfer ".

  In step S3011, the mobile station UE performs a detach process from the cell # 4 and performs a synchronization process with the cell # 2.

  In step S3012, the mobile station UE transmits “Random Access Preamble” to the radio base station DeNB # 2, and in step S3013, the radio base station DeNB # 2 transmits to the mobile station UE in the uplink. Radio resources are allocated and “TA” for the mobile station UE is transmitted, and in step S3014, the mobile station UE transmits “RRC Connection Reconfiguration Complete” to the radio base station DeNB # 2.

  In step S3015, the radio base station DeNB # 2 transmits “(S1) UE Context Release” to the relay node RN # 3.

  In step S3016, the relay node RN # 3 determines that the destination of the received “(S1) UE Context Release” is the relay node RN # 4, and the relay node RN # 4 determines that the “(S1) UE Transfer “Context Release”.

  Here, the relay node RN # 4 determines that the destination of the received “(S1) UE Context Release” is the relay node RN # 4 itself, and terminates the “(S1) UE Context Release”.

  Before and after the handover procedure described above, there is no change in the S1 connection for the mobile station UE set between the exchange MME and the radio base station DeNB # 2.

  Fourth, referring to FIG. 8, in the mobile communication system according to the present embodiment, the handover from the cell # 2 under the radio base station DeNB # 2 of the mobile station UE to the cell # 4 under the relay node RN # 4 The operation when performing the procedure will be described.

  As illustrated in FIG. 8, in step S4001, the radio base station DeNB # 2 transmits “Measurement Control” to the mobile station UE being connected in the cell # 2.

  In step S4002, the mobile station UE transmits “Measurement Report” to the radio base station DeNB # 2 at a predetermined timing based on the “Measurement Control” described above.

  When the radio base station DeNB # 2 decides to start the handover procedure from the cell # 2 to the cell # 4 of the mobile station UE in step S4003, in step S4004, the radio base station DeNB # 2 instructs the relay node RN # 3 to “( S1) HO Required ”is transmitted.

  In step S4005, the relay node RN # 3 determines that the destination of the received “(S1) HO Required” is the relay node RN # 4, that is, the “(S1) HO Required” is the relay node RN # 4. The control signal is determined to be a control signal for the handover procedure for the subordinate cell # 4, and the “(S1) HO Required” is transferred to the relay node RN # 4.

  In step S4006, the relay node RN # 4 determines that the destination of the received “(S1) HO Required” is the relay node RN # 4 itself, that is, the “(S1) HO Required” is the relay node RN #. 4 is determined to be a control signal for the handover procedure for cell # 4 under the control, terminates the “(S1) HO Required”, and transmits “(S1) HO Command” to the relay node RN # 3. .

  In step S4007, the relay node RN # 3 determines that the destination of the received “(S1) HO Command” is the radio base station DeNB # 2, and the radio base station DeNB # 2 receives “(S1) HO Command "is transferred.

  In step S4008, the radio base station DeNB # 2 transmits “RRC Connection Reconfiguration” to the mobile station UE. In step S4009, the radio base station DeNB # 2 transmits “(S1) MME Status Transfer” to the relay node RN # 3. Send.

  In step S4010, the relay node RN # 3 determines that the destination of the received “(S1) MME Status Transfer” is the relay node RN # 4, and the relay node RN # 4 determines that the “(S1) MME Transfer "Status Transfer".

  In step S4011, the mobile station UE performs a detach process from the cell # 2, and performs a synchronization process with the cell # 4.

  In step S4012, the mobile station UE transmits “Random Access Preamble” to the relay node RN # 4. In step S4013, the relay node RN # 4 transmits radio resources in the uplink to the mobile station UE. , And transmits “TA” for the mobile station UE. In step S4014, the mobile station UE transmits “RRC Connection Reconfiguration Complete” to the relay node RN # 4.

  In step S4013, the relay node RN # 4 transmits “(S1) Path Switch Request” to the relay node RN # 3.

  Here, the relay node RN # 3 determines that the destination of the received “(S1) Path Switch Request” is the radio base station DeNB # 2, and sends the “(S1) “Path Switch Request” is transferred.

  In step S4016, the radio base station DeNB # 2 determines that the destination of the received “(S1) Path Switch Request” is the radio base station DeNB # 2 itself, and terminates the “(S1) Path Switch Request”. Then, “(S1) Path Switch Request ACK” is transferred to relay node RN # 3.

  Here, the relay node RN # 3 determines that the destination of the received “(S1) Path Switch Request ACK” is the relay node RN # 4, and determines “(S1) Path to the relay node RN # 4. Transfer Switch Request ACK.

  In step S4017, the relay node RN # 4 transmits “(S1) UE Context Release” to the relay node RN # 3.

  Here, the relay node RN # 3 determines that the destination of the received “(S1) UE Context Release” is the radio base station DeNB # 2, and the radio base station DeNB # 2 receives the “(S1) UE Context Release "is transferred.

  Here, the radio base station DeNB # 2 determines that the destination of the received “(S1) UE Context Release” is the radio base station DeNB # 2 itself, and terminates the “(S1) UE Context Release”.

  Before and after the handover procedure described above, there is no change in the S1 connection for the mobile station UE set between the exchange MME and the radio base station DeNB # 2.

  Next, the operation of the relay node RN according to the present embodiment will be described with reference to FIG.

  As illustrated in FIG. 9, in step S101, the relay node RN receives “S1 handover message” which is a control signal for handover procedure from another relay node RN (for example, a lower relay node RN) or the radio base station DeNB. In step S102, it is determined whether or not the destination of the “S1 handover message” is the relay node RN itself.

  Here, when it is determined that it is the relay node RN itself, this operation proceeds to step S103, and when it is determined that it is not the relay node RN itself, this operation proceeds to step S104.

  In step S103, the relay node RN performs processing corresponding to the “S1 hand over message”, and sends a response signal to the other relay node RN or the radio base station DeNB, which is a response signal to the “S1 hand over message”. ".

  In step S104, the relay node RN determines whether or not the destination of the “S1 handover message” is a lower relay node RN.

  If it is determined that the relay node is a lower relay node RN, the operation proceeds to step S105. If it is determined that the relay node is not a lower relay node RN, the operation proceeds to step S106.

  In step S105, the relay node RN transfers the “S1 handover message” to the lower relay node RN.

  In step S106, the relay node RN transfers the “S1 hand over message” to the upper relay node RN or the radio base station DeNB.

  According to the mobile communication system according to the first embodiment of the present invention, between the cell # 3 under the relay node RN # 3 and the cell # 4 under the relay node RN # 4 without involving the switching center MME. And handover of the mobile station UE between the cell # 4 under the relay node RN # 4 and the cell # 2 under the radio base station DeNB # 2 can be realized.

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

  The first feature of the present embodiment is that the radio base station DeNB # 2, the relay node RN # 3 (first relay node) connected to the radio base station DeNB # 2, and the relay node RN # 3 are connected. A relay node RN # 4 (second relay node), and an X2 interface is not set between the radio base station DeNB # 2 and the relay node RN # 3. The S1 interface is set, the X2 interface is not set between the relay nodes RN # 3 and RN # 4, the S1 interface is set, and the relay node RN of the mobile station UE is set. In the handover procedure between the cell under # 3 and the cell under relay node RN # 4, relay node RN # 3 is relay node RN # 4. It is summarized as being configured to terminate a control signal for handover procedure received through the al S1 interface.

  The second feature of the present embodiment is that the radio base station DeNB # 2, the relay node RN # 3 connected to the radio base station DeNB # 2, and the relay node RN # connected to the relay node RN # 3 4 between the radio base station DeNB # 2 and the relay node RN # 3, the X2 interface is not set, the S1 interface is set, and the relay node The X2 interface is not set between the RN # 3 and the relay node RN # 4, the S1 interface is set, the cell under the radio base station DeNB # 2 of the mobile station UE, and the relay node RN # 4 In the handover procedure with the subordinate cell, the relay node RN # 3 receives from the relay node RN # 4 via the S1 interface. The control signal for the handover procedure is transferred to the radio base station DeNB # 2 via the S1 interface, and the control signal for the handover procedure received from the radio base station DeNB # 2 via the S1 interface is transferred to the relay node RN. The gist is that it is configured to transfer to # 4 via the S1 interface.

  A third feature of the present embodiment is a relay node RN # 3 connected to the radio base station DeNB # 2 and the relay node RN # 4 (other relay nodes) via the S1 interface instead of the X2 interface. When the destination of the control signal for the handover procedure received via the S1 interface is determined and the destination of the control signal for the handover procedure is the relay node RN # 3, the handover procedure When the destination of the control signal for the handover procedure is the relay node RN # 4 or the radio base station DeNB # 2 and the reception unit 11 configured to terminate the control signal for the handover procedure, the control signal for the handover procedure is Forward to the relay node RN # 4 or the radio base station DeNB # 2 via the S1 interface And gist to a transmission unit 13 configured.

  Note that the operations of the exchange MME, the gateway device S-GW, the radio base station DeNB, the relay node RN, and the mobile station UE described above may be implemented by hardware or by a software module executed by a processor. It may be implemented by a combination of both.

  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 exchange MME, the gateway device S-GW, the radio base station DeNB, the relay node RN, and the mobile station UE. Further, the storage medium and the processor may be provided as a discrete component in the exchange MME, the gateway device S-GW, the radio base station DeNB, the relay node RN, and the mobile station UE.

  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. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

MME ... Switching station S-GW ... Gateway device DeNB ... Radio base station RN ... Relay node 11 ... Receiving unit 12 ... Determining unit 13 ... Transmitting unit UE ... Mobile station

Claims (3)

A mobile communication system comprising a radio base station, a first relay node connected to the radio base station, and a second relay node connected to the first relay node,
Between the radio base station and the first relay node, the X2 interface is not set, and the S1 interface is set,
An X2 interface is not set between the first relay node and the second relay node, and an S1 interface is set,
In a handover procedure between a cell under the second relay node of a mobile station and a cell under the first relay node, the first relay node receives the handover received from the second relay node via an S1 interface. A mobile communication system configured to terminate a control signal for a procedure. A mobile communication system comprising a radio base station, a first relay node connected to the radio base station, and a second relay node connected to the first relay node,
Between the radio base station and the first relay node, the X2 interface is not set, and the S1 interface is set,
An X2 interface is not set between the first relay node and the second relay node, and an S1 interface is set,
In a handover procedure between a cell under the radio base station and a cell under the second relay node of a mobile station, the first relay node receives the handover procedure from the second relay node via an S1 interface. The control signal for handover is transferred to the radio base station via the S1 interface, and the control signal for the handover procedure received from the radio base station via the S1 interface is sent to the second relay node. A mobile communication system characterized by being configured to transfer via an S1 interface. A relay node connected to the radio base station and other relay nodes via the S1 interface instead of the X2 interface,
A determination unit configured to determine a destination of a control signal for a handover procedure received via the S1 interface;
A receiver configured to terminate the control signal for the handover procedure when the destination of the control signal for the handover procedure is the relay node;
When the destination of the control signal for the handover procedure is the other relay node or the radio base station, the control signal for the handover procedure is sent to the other relay node or the radio base station via the S1 interface. And a transmission unit configured to transfer the relay node.

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