JP2012009963A - Mobile communication method and relay node - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a relay node RN be in a DRX state in a backhaul with a radio base station DeNB to be operated with an access line for a mobile station UE being stopped.SOLUTION: A mobile communication method according to the present invention comprises the step in which the relay node RN, in receiving a "DRX Command MAC control element" from the radio base station DeNB via an R-PDCCH, transits to the DRX state, and transmission of a radio wave destined for the mobile station UE is stopped.

Description

  The present invention relates to a mobile communication method 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”.

3GPP TS 36.300 (V10.0. 0), "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Month (10-UTR) 3GPP TR36.814 (V9.0.0), “Further Advancements for E-UTRA Physical Layer Aspects”, March 2010 3GPP TS36.321 (V9.3.0), "Media Access Control (MAC); Protocol specification", June 2010

  However, in such a mobile communication system, a method for putting the relay node RN into a DRX (Discontinuous Reception) state on the backhaul line with the radio base station DeNB and stopping and operating the access line for the mobile station UE is clarified. There was a problem that it was not specified.

  Therefore, the present invention has been made in view of the above-described problems. The relay node RN is placed in the DRX state in the backhaul line with the radio base station DeNB, and the access line for the mobile station UE is stopped and operated. An object of the present invention is to provide a mobile communication method and a relay node.

  A first feature of the present invention is a mobile communication method, in which a relay node enters an intermittent reception state when receiving control information from a radio base station via a physical downlink control channel addressed to the relay node. The gist of the present invention is to have a step of transitioning and stopping transmission of radio waves addressed to the mobile station.

  A second feature of the present invention is a mobile communication method, wherein a relay node transitions to an intermittent reception state when a predetermined timer expires, and stops transmitting radio waves addressed to a mobile station, and the relay And a step of resetting the predetermined timer when the node receives control information from the radio base station via a physical downlink control channel addressed to the relay node.

  A third feature of the present invention is a relay node, and when receiving control information from a radio base station via a physical downlink control channel addressed to the relay node, the reception status of the relay node is intermittently received. The gist is to provide a control unit configured to change to a state and stop transmission of radio waves addressed to the mobile station.

  A fourth feature of the present invention is a relay node, wherein when a predetermined timer expires, the reception state of the relay node is changed to an intermittent reception state, and transmission of radio waves addressed to a mobile station is stopped. The control unit is configured to reset the predetermined timer when control information is received from the radio base station via a physical downlink control channel addressed to the relay node. It is a summary.

  As described above, according to the present invention, the mobile communication method that enables the relay node RN to be placed in the DRX state on the backhaul line with the radio base station DeNB and to stop and operate the access line for the mobile station UE. 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 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.

(Mobile communication system according to the first embodiment of the present invention)
With reference to FIG. 1 thru | or FIG. 3, the mobile communication system which concerns on the 1st Embodiment of this invention is demonstrated.

  As shown in FIG. 1, the mobile communication system according to the present embodiment is an LTE-Advanced mobile communication system, and includes a radio base station DeNB, a relay node RN, and the like.

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

  As illustrated in FIG. 2, the relay node RN includes a control unit 11, a Un interface, and a Uu interface.

  The Un interface 12 is configured to serve as an interface with the radio base station DeNB.

  The Uu interface 13 is configured to serve as an interface with the mobile station UE.

  The control unit 11 is configured to control the reception state (DRX state or non-DRX state) of the relay node RN.

  For example, when the control unit 11 receives “DRX Command MAC control element” from the radio base station DeNB via an R-PDCCH (Relay-Physical Downlink Control Channel), the reception state of the relay node RN is changed to the DRX state. The transmission is configured to stop transmission of radio waves addressed to the mobile station UE.

  Alternatively, when “DRX inactive timer” expires, the control unit 11 is configured to transition the reception state of the relay node RN to the DRX state and stop transmission of radio waves addressed to the mobile station UE.

  In such a case, the control unit 11 is configured to reset “DRX inactive timer” when receiving predetermined control information from the radio base station DeNB via the R-PDCCH.

  Here, the control unit 11 may be configured to release the setting of the Un subframe in the Uu interface 13 when the reception state of the relay node RN is changed to the DRX state.

  On the other hand, the control unit 11 is configured to change the reception state of the relay node RN to the non-DRX state by performing a random access procedure, and resume transmission of radio waves addressed to the mobile station UE.

  For example, when the control unit 11 receives predetermined control information from the radio base station DeNB via the R-PDCCH, the control unit 11 changes the reception state of the relay node RN to the non-DRX state, and the radio wave addressed to the mobile station UE May be configured to resume transmission.

  Here, the radio base station DeNB is configured to request to perform a random access procedure for synchronization in the uplink by transmitting “Dedicated Preamble” as predetermined control information via the R-PDCCH. It may be.

  For example, when there is downlink data addressed to the mobile station UE, the radio base station DeNB may transmit the predetermined control information, and it is necessary to operate the relay node RN in a non-DRX state. When it is determined, the predetermined control information may be transmitted.

  Further, when an uplink scheduling request (Scheduling Request) is generated in the relay node RN, the control unit 11 performs a random access procedure to change the reception state of the relay node RN to the non-DRX state, You may be comprised so that transmission of the electromagnetic wave addressed to the mobile station UE may be restarted.

  For example, even when the relay node RN is operated in the DRX state, only the receiver in the Uu interface is turned on, and the mobile station that is communicating with the radio base station eNB adjacent to the relay node RN The scheduling request may be generated based on the signal reception level of the UE.

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

  As shown in FIG. 3, in step S1001, the radio base station DeNB, from the viewpoint of energy saving, when the mobile station UE in the “RRC_CONNECTED state” does not exist in the cell under the relay node RN or when it is late at night, etc. When it is determined that the reception state of the relay node RN should be operated as the DRX state, “DRX Command MAC control element” is transmitted to the relay node RN via the R-PDCCH.

  When the relay node RN receives “DRX Command MAC control element”, the relay node RN transits to the DRX state in Step 1002 and stops transmission of radio waves addressed to the mobile station UE in Step S1003.

  Here, the relay node RN may release the setting of the Un subframe when transitioning to the DRX state.

  Thereafter, in step S2001, when the radio base station DeNB determines that the reception state of the relay node RN should be operated as the non-DRX state, the radio base station DeNB sends “RA Preamble to the relay node RN via the R-PDCCH. “Assignment”.

  When the relay node RN receives “RA Preamble Assignment”, the relay node RN transits to a non-DRX state in Step S2002. In Step S2003, the “RA Preamble Assignment” assigned to the radio base station DeNB by the “RA Preamble Assignment”. ".

  When the relay node RN receives “RA Response” transmitted by the radio base station DeNB in step S2004, the relay node RN resumes transmission of radio waves addressed to the mobile station UE in step S2005.

  Here, when the setting of the Un subframe is released, the relay node RN resumes the transmission of the radio wave addressed to the mobile station UE after setting the Un subframe.

  According to the mobile communication system according to the present embodiment, it is possible to appropriately control the stop / restart of transmission of radio waves addressed to the mobile station UE via the Uu interface while appropriately controlling the reception state of the relay node RN.

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

  A first feature of the present embodiment is a mobile communication method, in which a relay node RN transmits a “DRX Command MAC control” from a radio base station DeNB via an R-PDCCH (physical downlink control channel addressed to a relay node). The gist of the invention is that it has a step of transitioning to a DRX state (intermittent reception state) when receiving "element (control information)" and stopping transmission of radio waves addressed to the mobile station UE.

  A second feature of the present embodiment is a mobile communication method, in which the relay node RN transitions to a DRX state when the “DRX inactive timer (predetermined timer)” expires, and the radio wave addressed to the mobile station UE The gist is that the relay node RN includes a step of stopping transmission and a step of resetting “DRX inactive timer” when the relay node RN receives control information from the radio base station DeNB via the R-PDCCH.

  In the first and second features of this embodiment, the relay node RN releases the setting of the Un subframe (subframe used with the radio base station) when transitioning to the DRX state. Also good.

  In the first and second features of the present embodiment, the relay node RN makes a transition to a non-DRX state (continuous reception state) by performing a random access procedure, and resumes transmission of radio waves addressed to the mobile station UE. You may have a process.

  In the first and second features of the present embodiment, when the relay node RN receives control information from the radio base station DeNB via the R-PDCCH, by performing a random access procedure, the non-DRX state It may have a process which changes to, and restarts transmission of the electric wave addressed to mobile station UE.

  In the first and second features of this embodiment, after the relay node RN performs a random access procedure and then sets an Un subframe, the relay node RN transits to a non-DRX state, and receives radio waves addressed to the mobile station UE. There may be a step of resuming transmission of.

  The third feature of the present embodiment is the relay node RN, and when the “DRX Command MAC control element” is received from the radio base station DeNB via the R-PDCCH, the reception state of the relay node RN is changed to DRX. The gist is to include a control unit 11 configured to change to a state and stop transmission of radio waves addressed to the mobile station UE.

  The fourth feature of the present embodiment is the relay node RN. When the “DRX inactive timer” expires, the reception state of the relay node RN is changed to the DRX state, and the radio wave addressed to the mobile station UE is transmitted. The control unit 11 is configured to be stopped, and the control unit 11 resets “DRX inactive timer” when receiving control information from the radio base station DeNB via the R-PDCCH. The gist is that it is configured.

  In the third and fourth features of the present embodiment, the control unit 11 may be configured to release the setting of the Un subframe when transitioning the reception state of the relay node RN to the DRX state.

  In the third and fourth features of the present embodiment, the control unit 11 changes the reception state of the relay node RN to the non-DRX state by performing a random access procedure, and transmits a radio wave addressed to the mobile station UE. It may be configured to resume.

  In the third and fourth features of the present embodiment, when the control unit 11 receives control information from the radio base station DeNB via the R-PDCCH, by performing a random access procedure, the control unit 11 The reception state may be changed to the non-DRX state, and transmission of radio waves addressed to the mobile station UE may be resumed.

  In the third and fourth features of the present embodiment, the control unit 11 transitions the reception state of the relay node RN to the non-DRX state after setting the Un subframe after performing the random access procedure. The transmission of radio waves addressed to the mobile station UE may be resumed.

  The operations of the radio base station DeNB, the relay node RN, and the mobile station UE described above may be performed by hardware, may be performed by a software module executed by a processor, or may be performed by a combination of both. May be.

  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, 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, and the mobile station UE as discrete components.

  Although the present invention has been described in detail using the above-described embodiments, it is obvious to those skilled in the art that the present invention is not limited to the embodiments described in this 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.

UE ... mobile station DeNB ... radio base station RN ... relay node 11 ... control unit 12 ... Un interface 13 ... Uu interface

Claims (12)

  When the relay node receives control information from the radio base station via the physical downlink control channel addressed to the relay node, the relay node transitions to an intermittent reception state and includes a step of stopping transmission of radio waves addressed to the mobile station A mobile communication method characterized by the above. A relay node, when a predetermined timer expires, transitioning to an intermittent reception state and stopping transmission of radio waves addressed to a mobile station;
And a step of resetting the predetermined timer when the relay node receives control information from the radio base station via a physical downlink control channel addressed to the relay node. .   The mobile communication method according to claim 1 or 2, wherein the relay node releases the setting of a subframe used with the radio base station when transitioning to an intermittent reception state.   3. The mobile communication method according to claim 1, further comprising a step in which the relay node transitions to a continuous reception state by performing a random access procedure and restarts transmission of radio waves addressed to a mobile station. 4.   When the relay node receives control information from the radio base station via a physical downlink control channel addressed to the relay node, the relay node transits to a continuous reception state and resumes transmission of radio waves addressed to the mobile station The mobile communication method according to claim 4, wherein:   The relay node, after performing a random access procedure, setting a subframe to be used with the radio base station, and then resuming transmission of radio waves addressed to the mobile station. The mobile communication method according to claim 3. A relay node,
When control information is received from a radio base station via a physical downlink control channel addressed to the relay node, the reception state of the relay node is changed to an intermittent reception state and transmission of radio waves addressed to the mobile station is stopped. A relay node comprising a control unit configured as described above. A relay node,
When a predetermined timer expires, comprising a control unit configured to transition the reception state of the relay node to an intermittent reception state and stop transmission of radio waves addressed to the mobile station,
The control unit is configured to reset the predetermined timer when receiving control information from the radio base station via a physical downlink control channel addressed to the relay node. node.   The control unit is configured to release a setting of a subframe used with the radio base station when the reception state of the relay node is changed to an intermittent reception state. The relay node according to claim 7 or 8.   The control unit is configured to change a reception state of the relay node to a continuous reception state by performing a random access procedure, and resume transmission of radio waves addressed to a mobile station. The relay node according to 7 or 8.   When the control unit receives control information from the radio base station via a physical downlink control channel addressed to the relay node, the control unit shifts the reception state of the relay node to a continuous reception state, and The relay node according to claim 10, wherein the relay node is configured to resume transmission of radio waves.   The control unit, after performing a random access procedure, after setting the subframe used with the radio base station, transition the reception state of the relay node to a continuous reception state, addressed to the mobile station The relay node according to claim 9, wherein the relay node is configured to resume transmission of radio waves.