JP2011234133A - Mobile communication method and radio base station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect separately a state where signal transmission is suspended and a state where signal transmission/reception bandwidth or transmission time is decreased for a cell under the control of a neighboring radio base station eNB.SOLUTION: A mobile communication method according to the invention comprises: a step in which a radio base station eNB#1 transmits "eNB Configuration Update" to radio base station eNB#2/#3, which indicates that signal transmission is suspended in a cell#11 under the control of the radio base station eNB#1, when the radio base station eNB#1 suspends signal transmission in the cell#11 under the control thereof; and a step in which the radio base station eNB#1 transmits "eNB Configuration Update" to the radio base station eNB#2/#3, which indicates that signal transmission/reception bandwidth or transmission time is decreased for the cell#11 under the control of the radio base station eNB#1, when the radio base station eNB#1 decreases signal transmission/reception bandwidth or transmission time for the cell#11 under the control thereof.

Description

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

  In a mobile communication system using the LTE (Long Term Evolution) method, in order to suppress wasteful power consumption, a radio base station eNB transmits signals in a subordinate cell to a neighboring radio base station eNB via an X2 interface. It is configured to be able to control the start and stop of transmission (see, for example, Non-Patent Document 1).

  In order to suppress wasteful power consumption in such a mobile communication system, as shown in FIG. 10, the radio base station eNB reduces the signal transmission power by narrowing the frequency bandwidth to be used in the subordinate cell. It is comprised so that it can reduce (for example, refer nonpatent literature 2).

  Furthermore, in order to suppress wasteful power consumption in such a mobile communication system, as shown in FIG. 11, the radio base station eNB, in a subordinate cell, performs an MBSFN (Multicast / Broadcast over Single Frequency Network) subframe or a Blank subframe. By setting the frame, the signal transmission time can be reduced (for example, see Non-Patent Documents 2 and 3).

3GPP TS36.423 (V9.0.0), “Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 application protocol (X2AP)”, September 2009 3GPP R1-110028 3GPP R1-084686, “Updated WF on addressing forward compatibility in Rel-8”, November 2008

  However, the applicant has found the following problems in the above-described mobile communication system.

  When a radio base station eNB detects that signal transmission is stopped in a cell under the control of a neighboring radio base station eNB, the radio base station eNB obtains information related to the cell from the “NRT (Neighbor Relation Table)” managed by itself. By deleting, the management load of the NRT can be reduced.

  On the other hand, when a radio base station eNB detects that a signal transmission / reception bandwidth or transmission time is reduced in a cell under the control of a neighboring radio base station eNB, the radio base station eNB can perform communication in the cell. It is not preferable to delete the information related to the cell from the NRT managed by itself.

  Here, in the conventional mobile communication system, it is detected by the “eNB Configuration Update” received from the neighboring radio base station eNB that the transmission of the signal is stopped in the cell under the neighboring radio base station eNB. However, since it cannot be detected that the signal transmission / reception bandwidth or transmission time is reduced in such a cell, there is a problem in that the management load of the NRT cannot be reduced appropriately.

  Therefore, the present invention has been made in view of the above-described problems, and signal transmission has been stopped in a cell under the surrounding radio base station eNB and a transmission / reception band in a cell under the surrounding radio base station eNB. An object of the present invention is to provide a mobile communication method and a radio base station capable of distinguishing and detecting that the width or transmission time is reduced.

  A first feature of the present invention is a mobile communication method, in which when the first radio base station stops signal transmission in a subordinate cell, the first radio base station Transmitting a first message indicating that transmission of a signal has been stopped in the cell via an interface between the station and the second radio base station; and When the transmission / reception bandwidth or transmission time is reduced, a second message indicating that the transmission / reception bandwidth or transmission time of the signal is reduced in the cell is sent to the second radio base station via the interface. And the step of transmitting.

  A second feature of the present invention is a radio base station, which is configured to transmit a message to a peripheral radio base station via an interface with the peripheral radio base station. A transmitter, and when the transmitter stops transmitting a signal in the cell under the radio base station, the transmitter transmits a signal to the neighboring radio base station via the interface in the cell. The transmission unit is configured to transmit a first message indicating that transmission of the transmission is stopped, and the transmission unit transmits to the neighboring radio base stations when the transmission / reception bandwidth or transmission time of the signal is reduced in the cell. On the other hand, the gist is that the second message indicating that the transmission / reception bandwidth or transmission time of the signal is reduced in the cell is transmitted via the interface. .

  As described above, according to the present invention, signal transmission is stopped in cells under the surrounding radio base station eNB, and transmission / reception bandwidth or transmission time in the cells under the surrounding radio base station eNB is reduced. Thus, it is possible to provide a mobile communication method and a radio base station that can distinguish and detect what has been done.

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. FIG. 3 is a sequence diagram for explaining an operation of the mobile communication system according to the first embodiment of the present invention. It is a figure which shows the example of a format of "eNB Configuration Update" used in the mobile communication system which concerns on the 1st Embodiment of this invention. It is a figure which shows the example of a format of the information element "Served Cell Information" in "eNB Configuration Update" used in the mobile communication system which concerns on the 1st Embodiment of this invention. FIG. 3 is a sequence diagram for explaining an operation of the mobile communication system according to the first embodiment of the present invention. FIG. 3 is a sequence diagram for explaining an operation of the mobile communication system according to the first embodiment of the present invention. It is a figure which shows the example of a format of "Cell Activation Response" used in the mobile communication system which concerns on the 1st Embodiment of this invention. FIG. 3 is a sequence diagram for explaining an operation of the mobile communication system according to the first embodiment of the present invention. It is a figure for demonstrating the conventional mobile communication system. It is a figure for demonstrating the conventional mobile communication system.

(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 FIGS. The mobile communication system according to the present embodiment is an LTE mobile communication system.

  As shown in FIG. 1, the mobile communication system according to the present embodiment includes a radio base station eNB # 1 that manages cell # 11, a radio base station eNB # 2 that manages cells # 21 to # 23, and a cell #. And a radio base station eNB # 3 that manages 31 through # 33.

  Here, the area of the cell # 11 overlaps with the areas of the cells # 21, # 22, and # 23 in part geographically.

  Since the functions of the radio base stations eNB # 1 to eNB # 3 are basically the same, these will be collectively described below as functions of the radio base station eNB. As illustrated in FIG. 2, the radio base station eNB includes a reception unit 11, a control unit 12, and a transmission unit 13.

  The receiving unit 11 is configured to receive a message transmitted by a surrounding radio base station eNB via the X2 interface.

  The control unit 12 is configured to control the start and stop of signal transmission in the cell under the radio base station eNB, the transmission / reception bandwidth (frequency bandwidth) of the signal in the cell under the radio base station eNB, the transmission time, and the like. Has been.

  For example, as shown in FIG. 10, the control unit 12 is configured to reduce the signal transmission power by narrowing the frequency bandwidth to be used in the cell under the radio base station eNB. .

  Further, as shown in FIG. 11, the control unit 12 is configured to reduce the signal transmission time by setting an MBSFN subframe or a Blank subframe in a cell under the radio base station eNB. ing.

  In addition, the control part 12 may be comprised so that the transmission-and-reception bandwidth and transmission time of a signal may be reduced autonomously in the cell under the radio base station eNB.

  In addition, the control unit 12 transmits / receives a normal signal to / from a cell under the control of the radio base station eNB in response to a request from a neighboring radio base station eNB (for example, “Cell Activation Request”) or autonomously. You may be comprised so that it may determine returning to the state which transmits with a bandwidth and transmission time.

  In addition, when the receiving unit 11 receives “eNB Configuration Update” indicating that the transmission of the signal is stopped in the subordinate cell from the surrounding radio base station eNB, the control unit 12 transmits the cell to the cell from the NRT. It may be configured to delete such information.

  On the other hand, when the receiving unit 11 receives “eNB Configuration Update” indicating that the transmission / reception bandwidth or transmission time of the signal is reduced in the subordinate cell from the neighboring radio base station eNB, the control unit 12 Therefore, it may be configured not to delete the information related to the cell.

  The transmission unit 13 is configured to transmit a message to the surrounding radio base station eNB via the X2 interface.

  For example, when the control unit 12 stops signal transmission in a cell subordinate to the radio base station eNB, the transmission unit 13 transmits the signal in the cell to the surrounding radio base station eNB via the X2 interface. “ENB Configuration Update” indicating that the transmission is stopped is configured to be transmitted.

  In addition, when the control unit 12 reduces the transmission / reception bandwidth or transmission time of a signal in a cell under the radio base station eNB, the signal is transmitted to the surrounding radio base station eNB via the X2 interface. It is configured to transmit “eNB Configuration Update” indicating that the transmission / reception bandwidth or the transmission time is reduced.

  Further, when the control unit 12 returns the signal to the state in which the signal is transmitted in the normal signal transmission / reception bandwidth and the transmission time in the cell under the radio base station eNB, the control unit 12 passes the X2 interface to the surrounding radio base station eNB. Thus, the cell may be configured to transmit “eNB Configuration Update / Cell Activation Response” indicating that the cell has returned to a state in which a signal is transmitted with a normal signal transmission / reception bandwidth and transmission time.

  With reference to FIG. 3 thru | or FIG. 8, operation | movement of the mobile communication system which concerns on the 1st Embodiment of this invention is demonstrated.

  First, a first operation in the mobile communication system according to the present embodiment will be described with reference to FIGS.

  As shown in FIG. 3, when the radio base station eNB # 1 reduces the signal transmission / reception bandwidth or transmission time in the cell # 11, in step S1001, the radio base station eNB # 1 Then, “eNB Configuration Update” indicating that the signal transmission / reception bandwidth or transmission time is reduced in the cell # 11 is transmitted.

  In such a case, for example, as illustrated in FIG. 4, the radio base station eNB # 1 sets “energySaved” in the information element “Deactivation Indication” in the information element “Served Cells To Modify” in “eNB Configuration Update”. To do.

  Here, as shown in FIG. 4 and FIG. 5, the radio base station eNB # 1 uses the information element “Served Cell Information” in the “eNB Configuration Update” and the target cell by the information element “Served Cell Information”. It is possible to notify information specifying # 11, a signal transmission / reception bandwidth, a signal transmission time (MBSFN subframe setting information), and the like.

  Note that, when the radio base station eNB # 1 notifies that the signal transmission is stopped in the cell # 11, for example, as illustrated in FIG. 4, the information element “Served Cells To” in “eNB Configuration Update” is used. “Deactivated” is set in the information element “Deactivation Indication” in “Modify”.

  Secondly, a second operation in the mobile communication system according to the present embodiment will be described with reference to FIG. 4 to FIG.

  As illustrated in FIG. 6, in step S2001, when the radio base station eNB # 2 transmits “Cell Activation Request” to the radio base station eNB # 1, the radio base station eNB # 1 The signal is returned to the state in which the signal is transmitted with the transmission / reception bandwidth and the transmission time of the normal signal, and “Cell Activation Response” is transmitted to the radio base station eNB # 2 in Step S2002. In Step S2003, the cell # 11 An “eNB Configuration Update” indicating that the signal has been returned to the state of transmitting with the transmission / reception bandwidth and transmission time of the normal signal is transmitted.

  In such a case, for example, as illustrated in FIG. 4, the radio base station eNB # 1 sets “activated” to the information element “Deactivation Indication” in the information element “Served Cells To Modify” in “eNB Configuration Update”. To do.

  Further, for example, as illustrated in FIG. 4 and FIG. 5, the radio base station eNB # 1 uses the information element “Served Cell Information” in the information element “Served Cells To Modify” in the “eNB Configuration Update”. Information specifying the cell # 11, signal transmission / reception bandwidth, signal transmission time (MBSFN subframe setting information), and the like are set.

  Thirdly, a third operation in the mobile communication system according to the present embodiment will be described with reference to FIG. 4, FIG. 5, and FIG.

  As illustrated in FIG. 7, when the radio base station eNB # 1 autonomously determines to return the signal to the state in which the signal is transmitted with the normal signal power and the transmission time in the cell # 11, the radio base station eNB # 1 On the other hand, in step S3001, “eNB Configuration Update” indicating that the signal is returned to the state in which the signal is transmitted in the normal signal transmission / reception bandwidth and transmission time in cell # 11 is transmitted.

  In such a case, for example, as illustrated in FIG. 4, the radio base station eNB # 1 sets “activated” to the information element “Deactivation Indication” in the information element “Served Cells To Modify” in “eNB Configuration Update”. To do.

  Further, for example, as illustrated in FIG. 4 and FIG. 5, the radio base station eNB # 1 uses the information element “Served Cell Information” in the information element “Served Cells To Modify” in the “eNB Configuration Update”. Information specifying the cell # 11, signal transmission / reception bandwidth, signal transmission time (MBSFN subframe setting information), and the like are set.

  4thly, with reference to FIG. 8, the 4th operation | movement in the mobile communication system which concerns on this embodiment is demonstrated.

  As illustrated in FIG. 8, in step S4001, when the radio base station eNB # 2 transmits “Cell Activation Request” to the radio base station eNB # 1, the radio base station eNB # 1 The signal is returned to the state in which the signal is transmitted with the transmission / reception bandwidth and the transmission time of the normal signal. In step S4002, the signal is transmitted with the transmission / reception bandwidth and the transmission time of the normal signal to the radio base station eNB # 2. “Cell Activation Response” indicating that the transmission state has been returned is transmitted.

  In this case, for example, as illustrated in FIG. 9, the radio base station eNB # 1 transmits / receives information and a signal transmission / reception band that specify the target cell # 11 by the information element “Activated Cell List” in “Cell Activation Response”. A width, a signal transmission time (MBSFN subframe setting information), and the like are set.

  According to the mobile communication system according to the present embodiment, the radio base station eNB transmits / receives a signal in a cell under the control of the surrounding radio base station eNB, and transmission / reception of the signal in the cell under the surrounding radio base station eNB. Since it is possible to distinguish and detect that the bandwidth or transmission time has been reduced, it is possible to appropriately reduce the management load of the NRT.

  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 radio base station eNB # 1 (first radio base station) stops radio signal transmission in a subordinate cell # 11. Signal transmission in the cell # 11 to the eNB # 2 / # 3 (second radio base station) via the X2 interface between the radio base station eNB # 1 and the radio base station eNB # 2 / # 3 And when the radio base station eNB # 1 reduces the signal transmission / reception bandwidth or the transmission time in the cell # 11, the radio base station eNB # 1 transmits the “eNB Configuration Update (first message)” indicating that the radio base station is stopped. “ENB Configurat” indicating that the transmission / reception bandwidth or transmission time of the signal is reduced in the cell # 11 via the X2 interface to the station eNB # 2 / # 3. And summarized in that a step of transmitting an on Update (second message) ".

  In the first feature of the present embodiment, when the radio base station eNB # 1 returns to a state in which a signal is transmitted with normal signal power and transmission time in the cell # 11, the radio base station eNB # 2 / # 3 On the other hand, through the X2 interface, “eNB Configuration Update / Cell Activation Response (third message)” indicating that the cell # 11 has returned to the state in which the signal is transmitted in the normal signal transmission / reception bandwidth and transmission time. You may have the process to transmit.

  In the first feature of the present embodiment, the radio base station eNB # 1 transmits a signal in the cell # 11 in response to a request (“Cell Activation Request”) from the radio base station eNB # 2 / # 3. You may return to the state of transmitting with the transmission / reception bandwidth and transmission time.

  In the first feature of the present embodiment, the radio base station eNB # 1 may autonomously return to a state in which a signal is transmitted in the cell # 11 with a normal signal transmission / reception bandwidth and transmission time.

  The second feature of the present embodiment is the radio base station eNB # 1, which is configured to transmit a message to the neighboring radio base stations eNB # 2 / # 3 via the X2 interface. The transmission unit 13 is configured to transmit X2 to the radio base station eNB # 2 / # 3 when transmission of a signal is stopped in the cell # 11 under the radio base station eNB # 1. It is configured to transmit “eNB Configuration Update” indicating that signal transmission is stopped in the cell # 11 via the interface, and the transmission unit 13 transmits / receives a signal transmission / reception bandwidth or transmission time in the cell # 11. Signal transmission / reception bandwidth or transmission time in the cell # 11 via the X2 interface to the radio base station eNB # 2 / # 3. The gist of the present invention is that it is configured to transmit “eNB Configuration Update” indicating that the number of the eNBs is reduced.

  In the second feature of the present embodiment, when the transmission unit 13 returns to the state in which the signal is transmitted in the normal signal transmission / reception bandwidth and transmission time in the cell # 11, the transmission unit 13 transmits the signal to the radio base station eNB # 2 / # 3. On the other hand, it is configured to transmit “eNB Configuration Update / Cell Activation Response” indicating that the signal is returned to the state in which the signal is transmitted in the normal signal transmission / reception bandwidth and transmission time through the X2 interface. May be.

  In the second feature of the present embodiment, in response to a request (“Cell Activation Request”) from the radio base station eNB # 2 / # 3, a signal is transmitted with a normal signal transmission / reception bandwidth and transmission time in the cell # 11. You may comprise the control part 12 comprised so that it might determine returning to the state which transmits.

  In the second feature of the present embodiment, the control unit 12 configured to autonomously determine to return the signal to the state of transmitting the signal in the normal signal transmission / reception bandwidth and transmission time in the cell # 11. You may have.

  Note that the operation of the radio base station eNB described above may be implemented by hardware, may be implemented by a software module executed by a processor, or 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 radio base station eNB. Further, the storage medium and the processor may be provided in the radio base station eNB as a discrete component.

  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.

eNB ... wireless base station 11 ... receiving unit 12 ... control unit 13 ... transmitting unit

Claims (8)

When the first radio base station stops signal transmission in the subordinate cell, the first radio base station is connected to the second radio base station via the interface between the first radio base station and the second radio base station. Sending a first message indicating that signal transmission has been stopped in the cell;
When the first radio base station reduces the signal transmission power or transmission time in the cell, the signal transmission / reception bandwidth or transmission in the cell is transmitted to the second radio base station via the interface. And a step of transmitting a second message indicating that the time has been reduced.   When the first radio base station returns to a state in which signals are transmitted at a normal signal power and transmission time in the cell, signals are transmitted in the cell to the second radio base station via the interface. The mobile communication method according to claim 1, further comprising a step of transmitting a third message indicating that the state has returned to a state of transmission with a normal transmission / reception bandwidth and transmission time.   The said 1st radio base station returns to the state which transmits a signal with the normal transmission-and-reception bandwidth and transmission time in the said cell according to the request | requirement from the said 2nd radio base station. Mobile communication methods.   3. The mobile communication method according to claim 2, wherein the first radio base station autonomously returns a signal in the cell to a state in which the signal is transmitted with a normal transmission / reception bandwidth and transmission time. A wireless base station,
A peripheral wireless base station, comprising a transmitter configured to transmit a message via an interface with the peripheral wireless base station;
When the transmission unit stops signal transmission in a cell under the radio base station, it indicates to the neighboring radio base stations that signal transmission has been stopped in the cell via the interface. Configured to send a first message;
When the transmission unit reduces the transmission / reception bandwidth or transmission time of the signal in the cell, the transmission unit transmits the transmission / reception bandwidth or transmission time of the signal in the cell to the surrounding radio base station via the interface. A radio base station configured to transmit a second message indicating a reduction.   When the transmitter returns to a state in which signals are transmitted with normal signal power and transmission time in the cell, the transmitter transmits / receives signals to / from the surrounding radio base station via the interface. The radio base station according to claim 5, wherein the radio base station is configured to transmit a third message indicating that the state has returned to a state in which transmission is performed with a bandwidth and a transmission time.   In response to a request from the neighboring radio base station, the control unit is configured to determine to return the signal to a state in which transmission is performed in a normal transmission / reception bandwidth and transmission time in the cell. The radio base station according to claim 6.   The radio according to claim 6, further comprising a control unit configured to autonomously decide to return a signal to a state in which transmission is performed in a normal transmission / reception bandwidth and transmission time in the cell. base station.

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