JP4649203B2 - Mobile communication system and radio control apparatus - Google Patents

Description

  The present invention relates to a mobile communication system, a radio control apparatus, and a base station that include a radio control apparatus and a base station, and transmit the same downlink information to a plurality of cells using a downlink common channel.

  Conventionally, in a W-CDMA mobile communication system, when a mobile station receives downlink information transmitted through a downlink common channel, a mobile station wirelessly selects a cell with the smallest path loss in the received pilot channel from a plurality of cells. A link is detected as a cell to be established, and a downlink common channel (downlink information) is received only from the detected cell.

That is, in a conventional W-CDMA mobile communication system, unlike a dedicated channel capable of soft handover, a mobile station is configured to receive downlink common channels (downlink information) from a plurality of cells. Absent.
"W-CDMA mobile communication system", supervised by Keiji Tachikawa, Maruzen Co., Ltd. 3GPP TS 25.211 Release 1999

  However, as described above, in the conventional W-CDMA mobile communication system, since the mobile station can receive only the downlink common channel transmitted from one cell, in order to realize high-quality reception near the cell boundary. However, there is a problem that it is necessary to increase the transmission power of the downlink common channel, which causes deterioration of the downlink communication capacity.

  Therefore, the present invention has been made in view of the above points, and transmission of downlink common channels between a plurality of cells so that a mobile station can receive and combine downlink common channels from a plurality of cells. An object of the present invention is to provide a mobile communication system, a radio control apparatus, and a base station that control timing.

  A first feature of the present invention is a mobile communication system that includes a radio network controller and a base station, and transmits the same downlink information to a plurality of cells using a downlink common channel. A delay time from when the control device transmits downlink information to when the base station transmits the downlink information to each of the plurality of cells is measured. Based on the measured delay time, the base station The gist is to control the timing of transmitting downlink information to each of the plurality of cells.

  A second feature of the present invention is a radio control apparatus used in a mobile communication system in which a base station transmits the same downlink information to a plurality of cells using a downlink common channel. A measurement unit that measures a delay time from when the information is transmitted to when the base station transmits the downlink information to each of the plurality of cells, and the base station determines whether the downlink is based on the measured delay time. And a control unit that controls timing of transmitting information to each of the plurality of cells.

  According to this invention, the base station transmits the downlink information based on a delay time from when the radio control apparatus transmits the downlink information to when the base station transmits the downlink information to each of the plurality of cells. Since the timing to transmit to each of the plurality of cells can be controlled, the mobile station can receive and combine the downlink common channels from the plurality of cells.

  In the second feature of the present invention, the measuring unit may measure the delay time based on timing difference information acquired when synchronization between nodes between the radio network controller and the base station is established.

  In the second aspect of the present invention, the measurement unit may measure the delay time based on timing difference information acquired when common channel synchronization is established between the radio network controller and the base station.

  In the second aspect of the present invention, the measurement unit is a cell-specific timing offset that is a difference between a transmission timing of a base station common frame in the base station and a transmission timing of a cell-specific frame unique to each of the plurality of cells. And the delay time may be measured based on a sum of a transmission timing of the cell specific frame and a cell common channel timing offset that is a difference between a transmission timing of the cell common channel frame in each of the plurality of cells. .

  In the second aspect of the present invention, the control unit transmits the downlink information at a timing that is backed by the delay time from a reference transmission timing, and immediately transmits the downlink information to each of the plurality of cells. You may instruct them to do so.

  In the second aspect of the present invention, the measurement unit measures a delay time difference that is a difference between the measured delay time and a maximum allowable delay time in the plurality of cells, and the control unit converts the downlink information into the downlink information. It may be instructed to transmit to each of the plurality of cells after being delayed by a delay time difference.

  A third feature of the present invention is a base station that transmits the same downlink information to a plurality of cells using a downlink common channel, and the base station transmits the downlink information after transmitting the downlink information. An acquisition unit for acquiring a delay time difference that is a difference between a delay time until transmission of downlink information to each of the plurality of cells and a maximum allowable delay time in the plurality of cells; and delay by the acquired delay time difference And a transmitter that transmits the downlink information transmitted from the radio control apparatus to each of the plurality of cells.

  A fourth feature of the present invention is a base station that transmits the same downlink information to a plurality of cells using a downlink common channel, and a transmission timing instructed for each of the plurality of cells by a radio controller. And a transmitter that transmits the downlink information transmitted from the radio control apparatus to each of the plurality of cells.

  As described above, according to the present invention, the mobile station controls the transmission timing of the downlink common channel between the plurality of cells so that the mobile station can receive and combine the downlink common channels from the plurality of cells. A communication system, a radio network controller, and a base station can be provided.

(Configuration of mobile communication system according to the first embodiment of the present invention)
Hereinafter, 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. FIG. 1 is a diagram showing an overall configuration of a mobile communication system according to the present embodiment.

  As shown in FIG. 1, the mobile communication system according to the present embodiment includes two base stations 20A and 20B under the radio control apparatus 10, and the base station 20A includes two cells 1-1 and 1. -2 is managed, and the base station 20B manages two cells 2-1 and 2-2. The “cell” used in the present embodiment includes both the concept of a conventional cell and sector.

  In the mobile communication system according to the present embodiment, the base station is configured to transmit the same downlink information to a plurality of cells using the downlink common channel.

  Specifically, the base station 20A transmits the same downlink information to the cell 1-1 and the cell 1-2 using the downlink common channel for the cell 1-1 and the downlink common channel for the cell 1-2, respectively. To do. Also, the base station 20B uses the downlink common channel for cell 2-1 and the downlink common channel for cell 2-2 to transmit the downlink transmitted by the base station 20A to the cell 2-1 and the cell 2-2, respectively. The same downlink information as the information is transmitted.

  The mobile station 30 uses the downlink common channel for the cell 1-1, the downlink common channel for the cell 1-2, the downlink common channel for the cell 2-1 and the downlink common channel for the cell 2-2, respectively, 1-2, the same downlink information transmitted in the cell 2-1 and the cell 2-2 is received, and the maximum ratio combining or selective combining is received.

  The radio network controller 10 may be configured to transmit downlink information to the plurality of cells 1-1 to 2-2 without being conscious of the base stations 20A and 20B. You may be comprised so that downlink information may be transmitted with respect to each base station 20A and 20B via one link established between 20A and 20B.

  Each of the base stations 20A and 20B is configured to transmit the received downlink information to each of the accommodated cells using the downlink common channel for each cell.

  As shown in FIG. 2, the radio control apparatus 10 includes a delay time measurement unit 11, a delay time storage unit 12, and a transmission timing control unit 13.

  After the radio control apparatus 10 transmits downlink information, the delay time measuring unit 11 transmits the downlink information to the cells 1-1 and 1-2 (or 2-1 and the like) by the base station 20A (or 20B). The delay time until transmission to each of 2-2) is measured.

  The delay time measurement unit 11 is configured to measure the delay time described above based on timing difference information acquired when establishing synchronization between nodes between the radio network controller 10 and the base station 20A (or 20B). Also good.

  Specifically, as shown in FIG. 3, when establishing inter-node synchronization between the radio network controller 10 and the base station 20A (or 20B), the radio network controller 10 includes the base station 20A (or 20B). The base station 20A (or 20B) transmits a node synchronization response signal to the radio control apparatus 10 in response to the node synchronization request signal. The delay time measurement unit 11 acquires the above-described timing difference information (for example, “RFN_BFN timing offset” described later) from the node synchronization response signal received at this time.

  The delay time storage unit 12 stores the above-described delay time for each cell. For example, as illustrated in FIG. 4, the delay time storage unit 12 stores “base station”, “cell”, and “delay time” in association with each other.

  In the example of FIG. 4, the delay time from when the radio network controller 10 transmits downlink information to when the base station 20A transmits the downlink information to the cell 1-1 is “X1”.

  Further, the delay time from when the radio network controller 10 transmits downlink information to when the base station 20A transmits the downlink information to the cell 1-2 is “X2”.

  Further, the delay time from when the radio control apparatus 10 transmits downlink information to when the base station 20B transmits the downlink information to the cell 2-1 is “X3”.

  Furthermore, the delay time from when the radio control apparatus 10 transmits downlink information to when the base station 20B transmits the downlink information to the cell 2-2 is “X4”.

  The transmission timing control unit 13 controls the timing at which the base station 20A (or 20B) transmits downlink information to each of a plurality of cells based on the delay time stored in the delay time storage unit 12. It is.

  Specifically, as illustrated in FIG. 5, the transmission timing control unit 13 transmits downlink information at a timing that is delayed by a delay time from the reference transmission timing, and immediately transmits the downlink information to each of a plurality of cells. To send it.

  In this embodiment, the transmission timing control unit 13 transmits downlink information at a timing that is backed by the delay time X1 from the reference transmission timing, and instructs to transmit the downlink information to the cell 1-1 immediately. .

  In addition, the transmission timing control unit 13 transmits downlink information at a timing that is backed by the delay time X2 from the reference transmission timing, and instructs the cell 1-2 to immediately transmit the downlink information.

  In addition, the transmission timing control unit 13 transmits downlink information at a timing that is backed by the delay time X3 from the reference transmission timing, and instructs the cell 2-1 to immediately transmit the downlink information.

  Further, the transmission timing control unit 13 transmits the downlink information at a timing that is backed by the delay time X4 from the reference transmission timing, and instructs the cell 2-2 to immediately transmit the downlink information.

(Operation of mobile communication system according to this embodiment)
With reference to FIG. 6, the operation of the mobile communication system according to the present embodiment will be described.

  As shown in FIG. 6, in step S1001, the delay time measuring unit 11 of the radio network controller 10 transmits downlink information from the radio network controller 10, and each of the base stations 20A and 20B transmits the downlink information to a plurality of cells. The delay time until transmission to each of 1-1 to 2-2 is measured.

  In step S <b> 1002, the delay time storage unit 12 of the radio network controller 10 stores the delay time measured by the delay time measurement unit 11 of the radio network controller 10.

  In step S1003, the transmission timing control unit 12 of the radio network controller 10 transmits downlink information at a timing that is earlier than the reference transmission timing by the above-described delay time, and immediately transmits the downlink information to the corresponding cells 1-1 to 2. Instruct -2 to send.

  In step S1004, the base stations 20A and 20B immediately transmit the received downlink information using the downlink common channel for each cell. Thereafter, the mobile station 30 performs maximum ratio combining or selective combining on a plurality of the same downlink information received in the plurality of cells 1-1 to 2-2.

(Operation and effect of the mobile communication system according to the present embodiment)
According to the mobile communication system according to the present embodiment, each of the base stations 20A and 20B transmits the downlink information to each of the plurality of cells 1-1 to 2-2 after the radio control apparatus 10 transmits the downlink information. Since the base stations 20A and 20B can control the timing of transmitting the downlink information to each of the plurality of cells 1-1 to 2-2 based on the delay time until the transmission is performed. The mobile station 30 can receive and combine the downlink common channels from the plurality of cells 1-1 to 2-2.

(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. 7 to FIG. Hereinafter, the difference between the mobile communication system according to the present embodiment and the mobile communication system according to the first embodiment will be mainly described.

  The delay time measurement unit 11 of the radio network controller 10 according to the present embodiment is configured to measure a delay time difference that is a difference between the measured delay time and the maximum allowable delay time in a plurality of cells.

  The delay time storage unit 12 stores a delay time and a delay time difference for each cell. For example, as illustrated in FIG. 7, the delay time storage unit 12 stores “base station”, “cell”, “delay time”, and “delay time difference” in association with each other.

  In the example of FIG. 7, the maximum allowable delay time in each cell is “X4”, and the base station 20A transmits the downlink information to the cell 1-1 after the radio network controller 10 transmits the downlink information. The delay time until completion is “X1”, and the delay time difference in the cell 1-1 is “Y1 (= X4−X1)”.

  The delay time from when the radio control apparatus 10 transmits downlink information to when the base station 20A transmits the downlink information to the cell 1-2 is “X2”, and the delay time difference relating to the cell 1-2 Is “Y2 (= X4−X2)”.

  Further, the delay time from when the radio control apparatus 10 transmits downlink information to when the base station 20B transmits the downlink information to the cell 2-1 is “X3”, and the delay time difference according to the cell 2-1 Is “Y3 (= X4-X3)”.

  Furthermore, the delay time from when the radio network controller 10 transmits downlink information to when the base station 20B transmits the downlink information to the cell 2-2 is “X4”, and the delay time difference relating to the cell 2-2 Is “Y4 (= X4−X4 = 0)”.

  The transmission timing control unit 13 transmits the transmission timing information including the above-described delay time difference to delay the downlink information by the delay time difference, and then transmits it to each of the plurality of cells 1-1 to 2-2. To instruct.

  Specifically, as shown in FIG. 8, the transmission timing control unit 13 delays the common channel for cell 1-1 including downlink information by a delay time difference Y1 from the reception time, and then performs Instruct to send.

  In addition, the transmission timing control unit 13 instructs the cell 1-2 to transmit the cell 1-2 common channel including downlink information after delaying the delay time difference Y2 from the reception time.

  In addition, the transmission timing control unit 13 instructs the cell 2-1 to transmit the common channel for the cell 2-1 including the downlink information after being delayed by the delay time difference Y3 from the reception time.

  Further, the transmission timing control unit 13 instructs to transmit the cell 2-2 common channel including downlink information to the cell 2-2 after being delayed by the delay time difference Y4 from the reception time (that is, immediately). To do.

  The transmission timing control unit 13 is configured to transmit transmission timing information including a delay time for each cell and a maximum allowable delay time in a plurality of cells, instead of the transmission timing information including the delay time difference described above. Also good.

  As shown in FIG. 9, the base station 20A according to the present embodiment includes a cell management unit corresponding to a cell managed by the base station 20A. FIG. 9 representatively shows the cell 1-1 processing unit 21 and the cell 1-2 processing unit 22 among the cell management units.

  In the present embodiment, since the configuration of the base station 20A and the configuration of the base station 20B are basically the same, the configuration of the base station 20A will be described below. In the present embodiment, the configuration of the cell 1-1 processing unit 21 and the configuration of the cell 1-2 processing unit 22 are basically the same. The configuration will be described.

  As shown in FIG. 9, the cell 1-1 processing unit 21 includes a signal receiving unit 21a, a transmission timing receiving unit 21b, and a signal transmitting unit 21c.

  The signal receiving unit 21a receives the same downlink information to be transmitted to the cell 1-1 transmitted from the radio control apparatus 10 using the downlink common channel.

  The transmission timing information receiving unit 21b receives transmission timing information including a delay time difference related to the cell 1-1 transmitted from the radio network controller 10.

  The transmission timing information receiving unit 21b includes a delay time from when the radio control apparatus 10 transmits downlink information to when the base station 20A transmits the downlink information to the cell 1-1, and a plurality of cells 1- The transmission timing information including the maximum allowable delay time in 1 to 2-2 may be received, and the above-described delay time difference may be calculated based on the received transmission timing information.

  The signal transmission unit 21c transmits the downlink information to the cell 1-1 using the downlink common channel after delaying the downlink information transmitted from the radio control apparatus 10 by the above-described delay time difference.

  The signal transmission unit 21c is configured to transmit the downlink information transmitted from the radio control apparatus 10 to the cell 1-1 according to the transmission timing instructed for the cell 1-1 by the radio control apparatus 10. It may be.

  With reference to FIG. 10, the operation of the mobile communication system according to the present embodiment will be described.

  As shown in FIG. 10, in step S2001, the delay time measurement unit 11 of the radio network controller 10 transmits downlink information from the radio network controller 10 so that each of the base stations 20A and 20B transmits the downlink information to a plurality of cells. The delay time until transmission to each of 1-1 to 2-2 is measured.

  In step S2002, the delay time storage unit 12 of the radio network controller 10 stores the delay time measured by the delay time measurement unit 11 of the radio network controller 10.

  In step S2003, the delay time measurement unit 11 of the radio network controller 10 calculates a delay time difference that is a difference between the measured delay time and the maximum allowable delay time in a plurality of cells.

  In step S2004, the transmission timing control unit 12 of the radio network controller 10 transmits the transmission timing information including the above-described delay time difference, thereby delaying the downlink information by the delay time difference, and then a plurality of cells 1-1 to 2. Instruct each -2 to transmit.

  In step S2005, the base stations 20A and 20B immediately transmit the received downlink information using the downlink common channel for each cell. Thereafter, the mobile station 30 performs maximum ratio combining or selective combining on a plurality of the same downlink information received in the plurality of cells 1-1 to 2-2.

(Operation and effect of the mobile communication system according to the present embodiment)
According to the mobile communication system according to the present embodiment, each of the base stations 20A and 20B transmits the downlink information to each of the plurality of cells 1-1 to 2-2 after the radio control apparatus 10 transmits the downlink information. On the other hand, based on the delay time until transmission, the timing at which each of the base stations 20A and 20B transmits the downlink information to each of the plurality of cells 1-1 to 2-2 can be controlled. Therefore, the mobile station 30 can receive and combine the downlink common channels from the plurality of cells 1-1 to 2-2.

(Modification 1)
In the mobile communication system according to the first modification of the present invention, the delay time measurement unit 11 of the radio network controller 10 transmits the base station common frame transmission timing and a plurality of cells 1-1 to 2 in the base station 20A (or 20B). -2 is a difference between the transmission timing of the cell-specific frame specific to each cell "cell-specific timing offset", the transmission timing of the cell-specific frame, and the cell common channel in each of the cells 1-1 to 2-2 The delay time described above may be measured based on the sum of the “cell common channel timing offset” that is the difference from the transmission timing of the frame.

  An example of a delay time measurement method according to the first modification will be described with reference to FIG.

  FIG. 11 shows the radio controller 10 frame transmission timing (RFN timing), base station 20A common frame transmission timing (BFN timing), cell 1-1 specific frame transmission timing (SFN timing), It shows the transmission timing (MFN timing) of the cell 1-1 common channel frame.

  Here, RFN is a frame number counter for the radio controller 10 frame, BFN is a frame number counter for the base station 20A common frame, and SFN is a frame number counter for the cell 1-1 unique frame. The MFN is a frame number counter for the cell 1-1 common channel frame.

  The base station 20A common frame is used in common in all the cells 1-1, 1-2, etc. managed by the base station 20A. The cell 1-1 unique frame is transmitted through the broadcast channel in the cell 1-1, and the common control channel such as a pilot channel and a synchronization channel is also transmitted at the same timing. The cell 1-1 common channel frame is applied to the common channel (multicast data) in the cell 1-1.

  In the mobile communication system according to the first modification, when inter-node synchronization is established between the radio network controller 10 and the base station 20A, the radio controller 10 frame transmission timing (RFN timing) and the base station 20A common frame transmission “RFN_BFN timing offset (timing difference information acquired when synchronization between nodes is established)” that is a difference from the timing (timing of BFN) is acquired.

  Also, “BFN_SFN timing offset (cell-specific timing offset) T1”, which is the difference between the transmission timing (BFN timing) of the base station 20A common frame and the transmission timing (SFN timing) of the cell 1-1 specific frame, It is managed by the station 20A. The “BFN_SFN timing offset T1” may be configured to be specified by the radio network controller 10.

  Further, “SFN_MFN timing offset (cell common channel timing offset) TC1” which is a difference between the transmission timing of the cell 1-1 unique frame (timing of SFN) and the transmission timing of the cell 1-1 common channel frame (timing of MFN). Is configured to be designated by the wireless control device 10.

  Here, the delay time measurement unit 11 of the radio network controller 10 uses “BFN_MFN timing offset T2” which is the sum of “BFN_SFN timing offset T1” and “SFN_MFN timing offset TC1” and “RFN_BFN timing offset”. Thus, the above-described delay time (in the example of FIG. 11, “RFN_BFN timing offset” − “BFN_MFN timing offset T2”) can be calculated.

  Therefore, for example, the transmission timing control unit 13 of the radio control apparatus 10 adjusts the “SFN_MFN timing offset TC1” based on the delay time described above, thereby receiving the downlink common channel from the plurality of cells in the mobile station and Synthesis can be realized.

(Modification 2)
In the mobile communication system according to the second modification of the present invention, the delay time measurement unit 11 of the radio network controller 10 uses the timing difference information acquired when the common channel synchronization is established between the radio network controller 10 and the base stations 20A and 20B. Based on the above, the delay time described above may be measured.

  Specifically, as shown in FIG. 12, when establishing common channel synchronization between the radio network controller 10 and the base stations 20A and 20B, the radio network controller 10 is common to the base stations 20A and 20B. The channel synchronization request signal is transmitted, and each of the base stations 20A and 20B transmits a common channel synchronization response signal to the radio network controller 10 according to the common channel synchronization request signal. The delay time measurement unit 11 acquires the above-described timing difference information from the common channel synchronization response signal received at this time.

  For example, the delay time measurement unit 11 of the radio network controller 10 uses the radio controller 10 frame transmission timing (RFN timing) and the cell common channel frame in each cell as the timing difference information when the above common channel synchronization is established. The above-described delay time can be measured by obtaining the difference from the transmission timing (MFN timing).

  Then, the transmission timing control unit 13 of the radio network controller 10 adjusts “SFN_MFN timing offset TC1” based on the delay time described above, thereby receiving and combining downlink common channels from a plurality of cells in the mobile station. Can be realized.

  Although the present invention has been described in detail with reference to the embodiments, it will be apparent to those skilled in the art that the present invention is not limited to the embodiments described herein. The apparatus of the present invention can be implemented as modifications and changes 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 application is for illustrative purposes and does not have any limiting meaning to the present invention.

1 is an overall configuration diagram of a mobile communication system according to an embodiment of the present invention. It is a functional block diagram of the radio | wireless control apparatus which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the method to measure delay time by the delay time measurement part of the radio | wireless control apparatus which concerns on the 1st Embodiment of this invention. It is a figure which shows an example of the memory content in the delay time memory | storage part of the radio | wireless control apparatus which concerns on the 1st Embodiment of this invention. FIG. 3 is a diagram for explaining a method of transmitting a downlink common channel to a plurality of cells in the mobile communication system according to the first embodiment of the present invention. 3 is a flowchart showing an operation of the mobile communication system according to the first embodiment of the present invention. It is a figure which shows an example of the memory content in the delay time memory | storage part of the radio | wireless control apparatus which concerns on the 2nd Embodiment of this invention. It is a figure for demonstrating the method to transmit a downlink common channel with respect to several cells in the mobile communication system which concerns on the 2nd Embodiment of this invention. It is a functional block diagram of the base station which concerns on the 2nd Embodiment of this invention. 7 is a flowchart showing an operation of the mobile communication system according to the second embodiment of the present invention. It is a figure for demonstrating the method to measure delay time by the delay time measurement part of the radio | wireless control apparatus which concerns on the modification 1 of this invention. It is a figure for demonstrating the method to measure delay time by the delay time measurement part of the radio | wireless control apparatus which concerns on the modification 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Radio control apparatus 11 ... Delay time measurement part 12 ... Delay time memory | storage part 13 ... Transmission timing control part 20A, 20B ... Base station 21 ... Cell 1-1 process part 21 ... Cell 1-2 process part 21a, 22a ... Signal receivers 21b, 22b ... Transmission timing information receivers 21c, 22c ... Signal transmitters

Claims (8)

A mobile communication system comprising a radio controller and a base station and transmitting the same downlink information to a plurality of cells using a downlink common channel,
A measurement unit that measures a delay time from when the radio control apparatus transmits downlink information to when the base station transmits the downlink information to each of the plurality of cells;
A control unit for controlling timing at which the base station transmits the downlink information to each of the plurality of cells based on the measured delay time ;
Comprising
The measurement unit includes a cell-specific timing offset that is a difference between a transmission timing of a base station common frame in the base station and a transmission timing of a cell-specific frame unique to each of the plurality of cells, and a transmission timing of the cell-specific frame. And the delay time is measured based on a sum of a cell common channel timing offset which is a difference between a transmission timing of a cell common channel frame in each of the plurality of cells . A radio control apparatus used in a mobile communication system in which a base station transmits the same downlink information to a plurality of cells using a downlink common channel,
A measurement unit that measures a delay time from when the radio control apparatus transmits downlink information to when the base station transmits the downlink information to each of the plurality of cells;
A control unit for controlling the timing at which the base station transmits the downlink information to each of the plurality of cells based on the measured delay time ;
The measurement unit includes a cell-specific timing offset that is a difference between a transmission timing of a base station common frame in the base station and a transmission timing of a cell-specific frame unique to each of the plurality of cells, and a transmission timing of the cell-specific frame. And the delay time is measured based on a sum of a cell common channel timing offset which is a difference between a transmission timing of a cell common channel frame in each of the plurality of cells .   The radio control apparatus according to claim 2, wherein the measurement unit measures the delay time based on timing difference information acquired when synchronization between nodes between the radio control apparatus and the base station is established. .   The radio network controller according to claim 2, wherein the measurement unit measures the delay time based on timing difference information acquired when common channel synchronization is established between the radio network controller and the base station. .   The control unit transmits the downlink information at a timing that is backed by the delay time from a reference transmission timing, and instructs to immediately transmit the downlink information to each of the plurality of cells. The radio control apparatus according to claim 2. The measuring unit measures a delay time difference which is a difference between the measured delay time and a maximum allowable delay time in the plurality of cells;
The radio control apparatus according to claim 2, wherein the control unit instructs the downlink information to be transmitted to each of the plurality of cells after being delayed by the delay time difference. The control unit according to claim 2, wherein the control unit controls the timing at which the base station transmits the downlink information to each of the plurality of cells by adjusting the cell common channel timing offset. Wireless control device.
  The measurement unit measures the delay time based on a difference between a timing at which the radio control apparatus transmits the downlink information and a transmission timing of the cell common channel frame transmitted by the base station. The radio control apparatus according to claim 2.

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