JP4755550B2 - Base station, control station, and radio communication control method - Google Patents

Description

  The present invention relates to a base station, a control station, and a radio communication control method for smoothly controlling switching at the time of cell change in a mobile communication system.

2. Description of the Related Art In mobile communication systems using mobile phones that are currently popularized, the entire service area is divided into radio zones called cells, and communication services are provided for each mobile phone in units of cells. Such a system includes a plurality of base stations that cover a cell, a mobile station that performs communication by setting a radio channel between these base stations, and a control station that manages the plurality of base stations. Yes. In addition, the control station is connected to a trunk network including an exchange device and the like. In such a configuration, data transmission in communication between the trunk network and the mobile station is performed via the control station and the base station. In particular, in order to relay the wired communication section between the trunk network / control station and the base station and the wireless communication section between the base station and the mobile station, the base station sends from the trunk network / control station. It has a function of temporarily buffering data.
On the other hand, high-speed and large-capacity downlink high-speed packet communication such as HSDPA (High Speed Downlink Packet Access) and 1x EV-DO has been standardized and developed (for example, see Non-Patent Documents 1 and 2). The main feature of such a high-speed packet communication system is that an adaptive modulation / coding system is used according to the radio conditions of the mobile station that is receiving data. In this adaptive modulation / coding system, the radio transmission rate can be changed in time according to the radio conditions of the mobile station. For example, in HSDPA, the throughput can be improved by the modulation scheme of the radio channel, the number of HS-PDSCH codes, and the coding rate according to the radio state between the mobile station and the base station. In the 3GPP system, the control station is called “RNC (Radio Network Controller)”.

  By the way, in the case of the mobile communication system having the above configuration, when the transmission speed of the wired communication section is higher than the transmission speed of the wireless communication section, the data tends to be accumulated in the temporary buffer of the base station to be relayed. When the transmission speed of the wired communication section is lower than the transmission speed of the section, the data tends to be depleted in the temporary buffer of the relaying base station. The temporary buffer capacity of the relaying base station is finite, data that overflows the buffer is discarded, and the use efficiency of radio resources can be improved by depleting the buffering of the relaying base station. Therefore, if there is a difference between the transmission speed of the wireless communication section and the transmission speed of the wired communication section, the transmission efficiency will deteriorate due to data discard due to buffer overflow, or the wireless resource utilization efficiency will decrease due to buffer depletion. Cause. In order to avoid these two problems, it is necessary to control the transmission speed of the wireless communication section and the transmission speed of the wired communication section as much as possible.

  From the viewpoint of suppressing signal discard at the base station in communication between the trunk network and the mobile station, the data inflow control from the control station to the base station is controlled according to the amount of data remaining in the buffer at the base station. In a communication system in which the transmission speed of a wireless communication section such as a high-speed packet communication method fluctuates greatly, a wireless resource usage efficiency due to buffer depletion has already been proposed. There has been proposed a method for preventing degradation of transmission efficiency of a system due to degradation and occurrence of retransmission control caused by data discard due to buffer overflow (see, for example, Patent Document 2).

With reference to FIG. 12, the control method of the data inflow amount currently disclosed by these patent documents is demonstrated. However, signals unnecessary for explanation are omitted.
First, when the control station is in a state of receiving data addressed to the mobile station from the trunk network, the control station transmits data to the base station in accordance with the transmission rate of the base station (step S601).
In the base station, data is transmitted at a wireless transmission speed to the mobile station (step S602), and when data is received at a speed exceeding the wireless transmission speed, the data cannot be transmitted immediately. (Step S603).

  At this time, a value obtained by dividing the amount of data stored in the buffer by the wireless transmission speed is a “buffer dwell time” that is a time during which all data in the buffer can be transmitted. The base station monitors whether this buffer residence time exceeds the threshold, and if the buffer residence time exceeds the threshold, an “inflow control signal” for regulating the inflow from the control station using the sub-layer signal. Notification is made (step S604). The control station that has received the inflow amount control signal performs data transmission based on the data transmission amount specified in the control signal.

Conversely, during data transmission (step S605), when the wireless transmission rate increases (step S606) and the buffer amount (buffer residence time) decreases (step S607), if it falls below the threshold, The base station notifies the control station of information for canceling the transmission restriction using the sublayer signal (step S608). The control station that has received the information for deregulating changes the data transmission amount based on the data transmission amount specified in the control information.
By using such a method, the inflow amount to the base station can be controlled with the buffer residence time, and the overflow of the buffer at the base station can be avoided by limiting the inflow amount of data to the base station. In addition, the buffer depletion at the base station can be avoided by releasing the restriction on the amount of data flowing into the base station.

The above description assumes wireless data transmission from a base station to a mobile station in the same cell. Here, in such a mobile communication system, when a mobile station moves across cells, cell change is performed. Switching of the base station called is performed. At the time of cell change, first, a control signal for cell change is transmitted from the control station, and the cell change timing is transmitted to both the base station to be changed and the base station to be changed. At this time, it has not been studied how to control the amount of data flowing from the control station to the base station. Here, the base station of the change source is the base station when the mobile station before the cell change receives data, in other words, the base station that covers the cell before the cell change, and the base station of the change destination moves after the cell change. In other words, the base station when the station receives data, in other words, the base station that covers the cell after the cell change.
JP 2002-77987 A JP 2005-57323 A 3GPP TR25.848 v4.0.0 3GPP2 C. S0024 Rev. 1.0.0

In packet communication such as HSDPA as described above, in a cell change between base stations, the control station transmits a “cell change control signal” to the base station, and changes the cell change timing to the base station of the change source and the change destination. Tell the station. At that timing, the transmission destination is switched so that downlink data flows from the control station to the base station to be changed. At this time, data transmission is stopped until all cell change operations are completed, that is, there is a problem that communication cannot be continuously performed. In addition, when performing a method of transmitting data by continuously performing communication after receiving a cell change control signal, the data flowing from the control station remains in the base station of the change, and the change If the original base station cannot transmit all remaining data before the cell change timing, the data cannot be correctly received by the mobile station. Further, there is a problem that communication cannot be continuously performed unless the data inflow from the control station is appropriately performed in the base station to be changed.
The present invention has been made in view of the above problems, and the problem is to prevent data transmission to the mobile station from being disconnected or data from being lost during a cell change. It is to provide a base station, a control station, and a wireless communication control method capable of performing the above.

In order to solve the above-mentioned problem, the invention described in claim 1 is a base station in a mobile communication system including a mobile station that communicates with the base station, and communication with the mobile station is a source of change In the case of a cell change to be changed from a base station to a destination base station, the cell change timing is received from the control station, and the cell change waiting time is earlier than the notified cell change timing. by sending a control signal indicating that the data flow amount to a base station serving as the modified source for the control station to zero, the data inflow into the modified source base station from said control station zero There is provided a base station characterized by comprising inflow amount control means for controlling to become .

According to the present invention, the base station communicates the mobile station with the mobile station by changing the base station from the base station to the base station to which the base station is to be changed. Therefore, it is possible to prevent disconnection of data transmission to the mobile station and loss of data by appropriately controlling the data inflow amount .

According to the present invention, by transmitting a control signal to the control station at a timing earlier than the cell change waiting time, the data in the buffer of the base station of the change source is transmitted to the mobile station by the timing of the cell change. Thus, since the amount of data inflow from the control station can be controlled, it is possible to prevent disconnection of data transmission to the mobile station and loss of data.
Further, according to the present invention, data loss and transmission efficiency deterioration can be prevented by controlling the data inflow amount even after a cell change.
The invention according to claim 2 further comprises calculation means for calculating the cell change waiting time in the base station according to claim 1 , wherein the calculation means is configured to store all data in the buffer of the base station of the change source. The time until transmission to the mobile station is calculated as the cell change waiting time.

According to the present invention, since the base station can transmit all the data in the buffer of the base station of the change source to the mobile station during the cell change waiting time, disconnection of data transmission to the mobile station and data transmission It is possible to prevent occurrence of omission.
According to a third aspect of the present invention, in the base station according to the second aspect , the calculating means includes a data amount in a buffer of a base station of a change source, a data inflow amount from the control station, and the mobile station. The cell change waiting time is calculated based on a wireless transmission rate for the mobile phone.

According to the present invention, an appropriate cell change waiting time can be easily calculated based on easily obtainable information .

According to the present invention, by controlling the data inflow amount to be zero, the control becomes easier than when the data inflow amount is not zero, and the cell change waiting time can be easily calculated.
The invention according to claim 4 is a control station in a mobile communication system including a plurality of base stations controlled by the control station and a mobile station that communicates with the base station, and communicates with the mobile station In the case of a cell change in which the base station is changed, at least the change source base station is notified of the cell change timing, and in response to the notification, the change source base station has a timing earlier than the cell change timing. Inflow control for controlling the amount of data inflow to the base station of the change to be zero based on the received control signal indicating that the amount of data inflow to the base station of the change source is zero Means are provided .

According to this invention, it is possible to control the data flow amount to change the source base station during the cell change, cutting or data of the data transmission to the mobile station by appropriately controlling the data flow amount It is possible to prevent occurrence of omission.

The invention according to claim 5 is a radio communication control method performed in a mobile communication system including a plurality of base stations controlled by a control station and a mobile station that communicates with the base station. A cell change timing notifying step for notifying the change source base station of the cell change timing, and the change source base station has a cell change waiting time longer than the cell change timing notified in the cell change timing notifying step. A control signal transmission step for transmitting a control signal indicating that the amount of data inflow to the base station as the change source is set to zero with respect to the control station at an early timing; and the control station transmits the control signal based on the control signal transmitted in the data inflow system for the inflow of data to be transmitted to said change source base station to zero A method to provide a wireless communication control method, which comprises a.
According to the present invention, it is possible to control the data inflow amount to the base station of the change source at the time of cell change, so by appropriately controlling the data inflow amount, disconnection of data transmission to the mobile station It is possible to prevent data loss.

  According to the present invention, the amount of data flowing into the base station of the change source is controlled at the time of a cell change when the base station communicating with the mobile station is changed from the base station of the change source to the base station of the change destination Therefore, by appropriately controlling the data inflow amount, it is possible to prevent disconnection of data transmission to the mobile station and data loss.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing an overall configuration of a mobile communication system according to an embodiment of the present invention. In this mobile communication system, a trunk network 60 including a switching device, an RNC 50 functioning as a control station, and a base station 40 are configured in a hierarchy. The mobile station 30 communicates with the base station 40 via a wireless line. The RNC 50 is a control device that controls a plurality of base stations 40 in the 3GPP system described above.

  FIG. 2 shows an example when a cell change is performed. As shown in the figure, when the mobile station 30 is in the radio zone of the base station 40a and moves to the radio zone of the base station 40b while communicating with the base station 40a, the mobile station 30 communicates with the mobile station 30. The base station that performs is changed from the base station 40a to the base station 40b. This switching of base stations is called cell change. In the above description, the base station 40a is referred to as a change-source base station, and the base station 40b is referred to as a change-destination base station.

FIG. 3 shows a protocol stack in the mobile communication network shown in FIG. The protocol stack of the mobile station 30 includes a physical layer facing the base station 40 and a data link layer facing the RNC 50.
The protocol stack of the base station 40 includes a physical layer facing the mobile station 30 and a physical layer and sublayer facing the RNC 50. The protocol stack of the RNC 50 includes a physical layer and sublayer facing the base station 40, and a data link layer facing the mobile station 30, and also includes a layer (not shown) facing the trunk network 60 side. . Here, the sublayer described above is a layer for exchanging control signals between the RNC 50 and the base station 40.

FIG. 4 shows the configuration of base station 40 shown in FIG.
The wired physical layer processing unit 401 communicates with the RNC 50. The sublayer processing unit 402 communicates with the RNC 50 regarding control signals. The sub-layer processing unit 402 includes an inflow amount control function 4021. The inflow amount control function 4021 transmits an inflow amount control signal for controlling the data inflow amount from the RNC 50 to the base station 40 to the RNC 50.

The signal processing unit 403 performs signal relay processing between the mobile station 30 and the RNC 50, temporary storage (buffering) of data in a buffer included in the base station 40, and the like. The radio physical layer processing unit 404 communicates with the mobile station 30.
The calculation unit 405 performs various calculations. For example, the calculation unit 405 calculates the cell change waiting time based on the data amount in the buffer of the base station 40, the data inflow amount from the RNC 50, and the wireless transmission rate to the mobile station 30. Here, the data inflow amount can be represented by a data amount flowing in per unit time.

The wireless transmission rate to the mobile station 30 can be measured by monitoring the wireless physical layer processing unit 404, and the data inflow amount can be measured by monitoring the wired physical layer processing unit 401. The amount of data remaining in the buffer can be measured by monitoring the signal processing unit 403.
Further, the calculation unit 405 calculates an appropriate data inflow amount from the RNC 50 based on the radio transmission rate of the base station 40 when the base station 40 becomes the change-destination base station due to cell change, and performs sublayer processing. The unit 402 notifies the RNC 50.

FIG. 5 shows the configuration of the RNC 50 shown in FIG.
The wired physical layer processing unit 501 communicates with the base station 40. The sublayer processing unit 502 communicates with the base station 40 regarding control signals. The sublayer processing unit 502 includes an inflow amount control function 5021. The inflow amount control function 5021 controls the data inflow amount from the RNC 50 to the base station 40 based on the “inflow amount control signal” sent from the base station 40.

The data link layer processing unit 503 communicates with the mobile station 30. The signal processing unit 504 performs signal relay processing and buffering between the mobile station 30 and the trunk network 60. The trunk network layer processing unit 505 communicates with the trunk network 60.
Next, with reference to the sequence diagram shown in FIG. 6, an example of operation when the base station with which the mobile station 30 communicates at the time of cell change is changed from the base station 40a to the base station 40b will be described. FIG. 7 shows the relationship between the data at that time. In FIG. 6 and FIG. 7, the same reference numerals are given to the equivalent parts.

In the normal state, as shown in FIG. 7, the inflow amount control function 4021 of the change-source base station 40a performs the data inflow amount D1 based on the buffer amount D3 retained in the buffer of the change-source base station 40a. Communication, while avoiding buffer overflow.
At the time of the cell change, the RNC 50 transmits a cell change control signal and transmits the cell change timing Tc to the change-source base station 40a and the change-destination base station 40b (step S701 in FIG. 6).

  The base station 40a that has received the cell change control signal, with respect to the RNC 50, uses the inflow amount control function 4021 at the time (early timing) before the cell change timing Tc by the cell change waiting time tw. An inflow amount control signal indicating "0" is transmitted (step S703 in FIGS. 6 and 7). Here, the “cell change waiting time tw” is a time during which the change-source base station 40a can transmit the data buffered in the change-source base station 40a to the mobile station 30. In this operation example, it is assumed that the numerical value of the cell change waiting time tw is determined in advance and stored in the memory of the base station 40a that is the change source.

  When the RNC 50 receives the inflow amount control signal from the base station 40a, the inflow amount control function 5021 stops data transmission to the base station 40a of the change source based on the inflow amount indicated by the control signal. As a result, the amount of data inflow from the RNC 50 to the change-source base station 40a becomes 0, and as shown in FIG. 7, data transmitted from the change-source base station 40a to the mobile station 30 is transferred to the change-source base station 40a. Only the data D4 in the accumulated buffer is obtained. If all the data in the aforementioned buffer can be transmitted to the mobile station 30 by the time of cell change, it is possible to suppress data loss.

After that, the RNC 50 performs switching at the cell change timing Tc notified to the base station 40 in advance (step S704 in FIG. 6).
At the same time, the change-destination base station 40b notifies the appropriate data inflow amount by the inflow amount control signal (step S705). Here, as an appropriate data inflow amount, for example, a value calculated from the wireless transmission speed in the base station 40b to be changed, a specified fixed value, or changed before the notification of the cell change control signal in step S701. There is a data inflow amount indicated by the inflow amount transmission signal transmitted from the original base station 40 a to the RNC 50. Thereby, data can be continuously transmitted from the RNC 50 to the base station 40b to be changed.

  An area covered by one base station 40 is divided into a plurality of smaller cells (also referred to as sectors), and there is a communication method in which communication is performed for each sector. In the operation example described above, the operation example in the case where the base station with which the mobile station 30 communicates is changed from the change-source base station 40a to the change-destination base station 40b has been described. In the sector change between different sectors, the cell change method according to the present invention may be applied.

Next, another operation example at the time of cell change will be described with reference to FIGS. In this operation example, the cell change waiting time tw calculated by the base station 40a as the source of change is used without using the predetermined cell change waiting time tw.
In step S701 of FIG. 6, when the base station 40a as the change source receives the cell change control signal, the calculation unit 405 includes the buffer amount D5 stored in the buffer at that time (hereinafter referred to as the calculation time), Based on the data inflow amount D1 and the wireless transmission speed D2, a time during which all the data amount that will be accumulated in the buffer can be transmitted is calculated, and this time is defined as a cell change waiting time tw (see FIG. 8 step S702). Here, as a method of calculating the cell change waiting time tw, for example, tw = (D5 + (D1−D2) × t) / D1. Note that t is the time from the calculation time to the cell change, and if the cell change waiting time tw is obtained when the “cell change control signal notification” is received, t has received the “cell change control signal notification”. It is equal to the time from the time point to the cell change time point Tc.

Next, similarly to the above-described operation example, the inflow amount control function 4021 of the base station 40 has an inflow indicating “inflow amount 0” to the RNC 50 at a time point before the cell change waiting time tw from the cell change timing Tc. An amount control signal is transmitted (step S703 in FIGS. 6 and 8).
As a result, from the time when the cell change timing is notified in step S701 to the time when the inflow amount control signal is notified as “inflow amount 0” in step S703, the RNC 50 can change the change source base station 40a as much as possible. A large amount of data can be introduced, and a larger amount of data can be transmitted to the mobile station 30.

  In the above-described embodiment, in step S703, the change-source base station 40a notifies the RNC 50 of the inflow amount control signal as “inflow amount 0”, so that from the RNC 50 during the cell change waiting time tw. Although the control is performed so that the data inflow amount to the base station 40a becomes zero, the data inflow amount is not limited to zero. That is, the data inflow amount is set so that the base station 40 can transmit the data buffered in the buffer of the base station 40a to be changed and the data inflow from the RNC 50 to the mobile station 30 during the cell change waiting time tw. If so, the data inflow amount may not be zero.

  As described above, the base station 40 communicates from the RNC 50 to the base station of the change source when the base station communicating with the mobile station 30 is changed from the base station 40a of the change source to the base station 40b of the change destination. By appropriately controlling the amount of data flowing into the station 40a, it becomes possible to prevent disconnection of data transmission to the mobile station 30 and loss of data. In addition, the maximum data can be transmitted by calculating the cell change waiting time.

  Note that the base station, the control station, and the radio communication control method according to the present invention can be applied to a communication system that performs hard handover, for example, HSDPA in 3GPP and CDMA2000 1xEV-DO in 3GPP2. It is possible. Hereinafter, configuration examples of the protocol stack, the mobile station 300, the base station 400, and the RNC 500 when the present invention is applied to HSDPA in 3GPP will be described.

  FIG. 9 shows a protocol stack in the mobile communication network when adapted to HSDPA. In HSDPA, since the MAC-d sublayer and the MAC-hs sublayer of the MAC sublayer are divided and arranged between the base station 400 and the RNC 500, data between entities of the MAC sublayer is provided between the base station 400 and the RNC 500. Will flow. This flow is called MAC-d flow.

The protocol stack of the mobile station 300 includes a physical layer and a MAC layer facing the base station 400. The MAC layer is divided into a layer facing the MAC-hs sublayer of base station 400 and a layer facing the MAC-d sublayer of RNC 500.
The protocol stack of the base station 400 includes a physical layer and a MAC-hs sublayer facing the mobile station 300, and a physical layer and FP layer facing the RNC 500.
The protocol stack of the RNC 500 includes a physical layer and an FP layer facing the base station 400, and a MAC-d sublayer facing the mobile station 300, and also includes a layer (not shown) facing the trunk network 600 side. ing.

  FIG. 10 shows the configuration of base station 400. The wired physical layer processing unit 44 communicates with the RNC 500. The FP layer processing unit 43 communicates with the RNC 500 regarding control signals, and further performs MAC-d flow processing. The inflow amount control unit 46 has the same function as the inflow amount control function 4021 described above, and transmits an inflow amount control signal for controlling the data inflow amount from the RNC 500 to the base station 400 to the RNC 500. The MAC-hs sublayer processing unit 42 performs buffering of data to a buffer provided in the base station 400, and signal processing for transmitting the data in the radio physical layer, for example, H-ARQ processing, adaptive modulation / coding Processes such as conversion processing are performed. The radio physical layer processing unit 41 communicates with the mobile station 300. The calculation unit 45 has the same function as the calculation unit 405 described above, and based on the data amount in the buffer of the base station 400, the data inflow amount from the RNC 500, and the wireless transmission rate to the mobile station 300, Calculate the cell change waiting time. Further, the calculation unit 45 calculates an appropriate data inflow amount from the RNC 500 based on the radio transmission speed of the base station 400 when the base station 400 becomes the change-destination base station due to cell change, and the FP layer The processing unit 43 notifies the RNC 500.

  FIG. 11 shows the configuration of RNC 500. The wired physical layer processing unit 51 communicates with the base station 400. The FP layer processing unit 52 communicates with the base station 400 regarding control information, and further performs MAC-d flow processing. The inflow amount control unit 55 has the same function as the inflow amount control unit 5021 described above, and the data inflow from the RNC 500 to the base station 400 based on the “inflow amount control signal” sent from the base station 400. Control the amount. The MAC-d sublayer processing unit 53 communicates with the mobile station 300 and performs signal relay processing and buffering between the mobile station 300 and the trunk network 600. The trunk network layer processing unit 54 communicates with the trunk network 600.

  Even in a mobile communication network having such a configuration based on HSDPA, the same cell change radio control scheme as that described in the above embodiment is executed, and the same effect can be obtained. In the above embodiment, the RNC corresponds to the control station, the inflow amount control signal corresponds to Capacity Allocation or HS-DSCH CAPACITY ALLOCATION in HSDPA, the cell change control signal is one of RRC messages, and the cell change timing Tc. Corresponds to Activation Time.

  It can be used for smooth switching at the time of cell change in a mobile communication system.

It is a figure which shows the whole structure of the mobile communication system which concerns on embodiment of this invention. It is a figure which shows the example of the cell change which concerns on the same embodiment. It is a figure which shows the protocol stack in the mobile communication network which concerns on the same embodiment. It is a figure which shows the structure of the base station which concerns on the same embodiment. It is a figure which shows the structure of RNC which concerns on the same embodiment. It is a sequence diagram which shows the operation example at the time of the cell change which concerns on the embodiment. It is a figure which shows the relationship between the data in the operation example which concerns on the same embodiment. It is a figure which shows the relationship between the data in the operation example which concerns on the same embodiment. It is a figure which shows the protocol stack in the mobile communication network which concerns on a modification. It is a figure which shows the structure of the base station which concerns on a modification. It is a figure which shows the structure of RNC which concerns on a modification. It is a figure which shows the control method of the conventional data inflow amount.

Explanation of symbols

30 mobile station 40 base station 40a source base station 40b destination base station 401 wired physical layer processing unit 402 sublayer processing unit 4021 inflow control function 403 signal processing unit 404 radio physical layer processing unit 405 calculation unit 50 RNC
501 Wired physical layer processing unit 502 Sublayer processing unit 5021 Inflow control function 503 Data link layer processing unit 504 Signal processing unit 505 Trunk network layer processing unit 60 Trunk network

Claims (5)

A base station in a mobile communication system including a plurality of base stations controlled by a control station and a mobile station that communicates with the base station,
In the case of a cell change in which communication with the mobile station is changed from a change-source base station to a change-destination base station, a notification of the cell change timing is received from the control station, and from the notified cell change timing by sending a control signal indicating that the zero data flow amount to a base station to be the change source at a timing earlier by cell change waiting time for the control station, from the control station of the changed source A base station comprising inflow amount control means for controlling the amount of data inflow to the base station to be zero . A calculation means for calculating the cell change waiting time;
The base station according to claim 1, wherein the calculation means calculates a time until all the data in the buffer of the base station of the change source is transmitted to the mobile station as the cell change waiting time . The calculating means calculates the cell change waiting time based on the amount of data in the buffer of the base station of the change source, the amount of data inflow from the control station, and the radio transmission rate for the mobile station. The base station according to claim 2, characterized in that: A control station in a mobile communication system including a plurality of base stations controlled by a control station and a mobile station that communicates with the base station,
At the time of a cell change in which a base station that communicates with a mobile station is changed, at least the base station of the change source is notified of the timing of the cell change, and in response to the notification, the base station of the change source Based on the control signal indicating that the data inflow amount to the change source base station received at a timing earlier than the timing is zero, the data inflow amount to the change source base station is made zero. A control station comprising inflow amount control means for controlling the inflow . In a radio communication control method performed in a mobile communication system including a plurality of base stations controlled by a control station and a mobile station that communicates with the base station,
  The control station, a cell change timing notification step of notifying the change source base station of the cell change timing;
  Inflow of data to the base station serving as the change source from the control station at a timing earlier than the cell change timing notified in the cell change timing notification step by a cell change waiting time. A control signal transmission step of transmitting a control signal indicating that the amount is zero;
  Based on the control signal transmitted in the control signal transmission step by the control station, a data inflow amount control step for reducing the inflow amount of data to be transmitted to the base station of the change source,
  A wireless communication control method comprising:

Images