JP2008141258A - Mobile communication system, base station controller, radio base station and communication control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent overflow of data to be stored into a buffer in a radio base station when the radio communication environment is deteriorated in data communication corresponding to QoS control. <P>SOLUTION: The PCF (point coordination function) 5 includes: a QoS rate deciding section 531 for deciding to reduce a QoS rate to be assigned to communication to be performed between a radio communication terminal and a communication destination device of the radio communication terminal, when receiving a notice of below threshold for indicating that a mean value of DRC (data rate control) in a predetermined time period is not more than a predetermined threshold; and a QoS rate notification section for notifying the communication destination device about the QoS rate decided by the QoS rate deciding section 531. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mobile communication system, a base station control device, a radio base station, and a communication control method that use a data communication method compatible with QoS control.

  In mobile communication systems using code division multiple access (CDMA), data communication speed is increasing. For example, 1xEV-DO Rev., which is a data communication system defined by cdma2000. A (hereinafter simply referred to as “Rev. A”) realizes a maximum data rate of up to about 1.8 Mbps in the upstream direction and about 3.0 Mbps in the downstream direction.

  Rev. A corresponds to communication quality (QoS) control in order to realize an IP-based voice call (IP phone) function and an IP-based TV phone (IP-TV phone) function. QoS control means control that prioritizes data communication related to an application with high real-time property over data communication related to an application with low real-time property during data communication.

  Rev. In the mobile communication system corresponding to A, the data rate of data communication is kept constant by assigning a communication band corresponding to the type of application executed by the wireless communication terminal. Here, the “communication band” means a line capacity that the wireless communication terminal can use for communication.

As a data rate control method during data communication, a method of controlling the data rate of data transmitted by a user terminal or server on the transmission side according to an allocated communication band has been proposed (see Patent Document 1). . Specifically, the user terminal or server on the transmission side controls the data rate by converting the data format of data to be transmitted to the user terminal on the reception side according to the allocated communication band.
Japanese Patent Laid-Open No. 2002-9826

  However, the communication environment in the wireless section between the wireless communication terminal and the wireless base station (hereinafter referred to as “wireless communication environment”) is likely to fluctuate. For this reason, even if the communication band is allocated, the communication band of the wireless section varies due to the variation of the wireless communication environment. On the other hand, in the wired section, the communication environment is stable, so the communication band is also stable.

  In the method described in Patent Document 1, communication band allocation is not performed in consideration of changes in the wireless communication environment. Therefore, when the wireless communication environment deteriorates and the communication band of the wireless section decreases, the communication band of the wireless section becomes narrower than the communication band of the wired section, and downlink data continues to be accumulated in the buffer in the wireless base station. become.

  As a result, the amount of data stored in the buffer in the radio base station exceeds the limit value, and data overflows. Since overflowed data is discarded, it becomes a big problem in applications with high real-time characteristics.

  In view of the above problems, the present invention provides a mobile communication system capable of avoiding overflow of data stored in a buffer in a radio base station when a radio communication environment deteriorates in data communication corresponding to QoS control. An object of the present invention is to provide a base station control device, a radio base station, and a communication control method.

  In order to achieve the above object, a first feature of the present invention is a mobile communication system comprising a radio base station (radio base station 3) and a base station controller (PCF 5) for controlling the radio base station. The radio base station receives data rate information (DRC) indicating an expected value of a downlink data rate estimated based on a reception state of the radio communication terminal (radio communication terminal 1) from the radio communication terminal. Unit (wireless communication unit 32), a data rate determination unit (DRC determination unit 353) that determines whether an average value of the data rate information over a certain period exceeds a preset data rate threshold value, and the data When it is determined by the rate determination unit that the average value does not exceed the data rate threshold value, a sub-threshold notification indicating that the average value does not exceed the data rate threshold value A transmission unit (communication I / F unit 33) that transmits a DRC sub-threshold notification) to the base station control device, and the base station control device receives the sub-threshold notification from the radio base station ( When the communication I / F unit 51) and the reception unit receive the sub-threshold notification, the communication I / F unit 51) is executed between the wireless communication terminal and a communication destination device (for example, the wireless communication terminal 2) of the wireless communication terminal. A determination unit (QoS rate determination unit 531) that determines to reduce a communication band assigned to communication, and a notification unit (QoS rate notification unit 532) that notifies the communication destination device of the communication band determined by the determination unit. It is a summary to provide.

  According to such a feature, the radio base station notifies the base station control device of a sub-threshold notification indicating that the average value of the data rate information over a certain period does not exceed a preset data rate threshold. When receiving the subthreshold notification, the base station control device determines to decrease the communication band, and notifies the determined communication band to the communication destination device of the wireless communication terminal.

  As a result, it is possible to detect the deterioration of the wireless communication environment and reduce the data rate of the data transmitted by the communication destination device of the wireless communication terminal before the data stored in the buffer unit of the wireless base station overflows. . Therefore, it is possible to provide a mobile communication system capable of avoiding overflow of data stored in the buffer in the radio base station.

  A second feature of the present invention is a mobile communication system comprising a radio base station and a base station controller that controls the radio base station, wherein the radio base station is based on a reception state of a radio communication terminal. A receiving unit that receives data rate information indicating an expected value of an estimated downlink data rate from the wireless communication terminal, and whether an average value of the data rate information over a certain period exceeds a preset data rate threshold A data rate determining unit for determining whether the average value does not exceed the data rate threshold by the data rate determining unit, between the wireless communication terminal and a communication destination device of the wireless communication terminal A transmission unit that transmits a reduction request (QoS rate reduction request) for reducing a communication band allocated to communication executed in step (b) to the base station control device, The control device is determined by the receiving unit that receives the reduction request from the radio base station, a determination unit that determines to reduce the communication band when the receiving unit receives the reduction request, and the determination unit And a notification unit that notifies the communication destination device of the communication band that has been set.

  According to such a feature, the radio base station transmits a communication band reduction request to the base station controller when the average value of the data rate information over a certain period does not exceed a preset data rate threshold. When receiving the request for reducing the communication band, the base station control apparatus determines to reduce the communication band, and notifies the communication destination apparatus of the wireless communication terminal of the determined communication band.

  As a result, it is possible to detect the deterioration of the wireless communication environment and reduce the data rate of the data transmitted by the communication destination device of the wireless communication terminal before the data stored in the buffer unit of the wireless base station overflows. . Therefore, it is possible to provide a mobile communication system capable of avoiding overflow of data stored in the buffer in the radio base station.

  The third feature of the present invention is that the average value of the data rate information indicating the expected value of the downlink data rate estimated based on the reception state of the wireless communication terminal exceeds a preset first data rate threshold. A sub-threshold notification indicating absence from the radio base station, and when the receiving unit receives the sub-threshold notification, the sub-threshold notification is executed between the radio communication terminal and a communication destination device of the radio communication terminal. It is a base station control device comprising: a determination unit that determines to reduce a communication band assigned to communication to be performed; and a notification unit that notifies the communication destination device of the communication band determined by the determination unit And

  A fourth feature of the present invention is according to the third feature of the present invention, wherein the reception unit sends a threshold value super-notification indicating that the average value exceeds a preset second data rate threshold value to the wireless base station. In summary, the determination unit determines to increase the communication band when the reception unit receives the threshold value super notification.

  A fifth feature of the present invention is that a reduction request for reducing a communication band allocated to communication executed between a wireless communication terminal and a communication destination device of the wireless communication terminal is transmitted to a wireless base station connected to the wireless communication terminal. A receiving unit that receives from the station, a determining unit that determines to reduce the communication band when the receiving unit receives the reduction request, and the communication band determined by the determining unit to the communication destination device The gist of the present invention is that it is a base station control device provided with a notification unit for notification.

  A sixth feature of the present invention relates to the fifth feature of the present invention, wherein the receiving unit receives an increase request for increasing the communication band from the radio base station, and the determining unit is configured so that the receiving unit When the increase request is received, the gist is to determine to increase the communication band.

  According to a seventh aspect of the present invention, there is provided: a receiving unit that receives data rate information indicating an expected value of a downlink data rate estimated based on a reception state of a wireless communication terminal; A data rate determination unit that determines whether or not an average value in a period exceeds a preset first data rate threshold, and the average value does not exceed the first data rate threshold by the data rate determination unit When it is determined, the gist is that the wireless base station includes a transmission unit that transmits a sub-threshold notification indicating that the average value does not exceed the first data rate threshold to the base station controller.

  An eighth feature of the present invention is according to the seventh feature of the present invention, wherein the data rate determination unit determines whether the average value exceeds a preset second data rate threshold, and transmits the transmission. When the data rate determination unit determines that the average value exceeds the second data rate threshold, the base station sends a threshold value super notification indicating that the average value exceeds the second data rate threshold. The gist is to transmit to the control device.

  A ninth feature of the present invention relates to the seventh feature of the present invention, and is stored in the buffer unit (buffer unit 34) for storing data that has not been transmitted to the wireless communication terminal, and in the buffer unit. A buffer determination unit (buffer determination unit 351) that determines whether or not the data amount of the data exceeds a preset buffer threshold value, and the transmission unit is configured so that the data amount is reduced by the buffer determination unit. When it is determined that the buffer threshold is exceeded and the average value is determined not to exceed the first data rate threshold by the data rate determination unit, the sub-threshold notification is transmitted to the base station controller The gist is to do.

  According to a tenth aspect of the present invention, there is provided: a receiving unit that receives data rate information indicating an expected value of a downlink data rate estimated based on a reception state of a wireless communication terminal; A data rate determining unit that determines whether or not an average value in a period exceeds a preset first data rate threshold, and the data rate determining unit determines that the average value does not exceed the data rate threshold A wireless base station comprising: a transmission unit that transmits to the base station control device a reduction request for reducing a communication band assigned to communication performed between the wireless communication terminal and a communication destination device of the wireless communication terminal. This is the gist.

  An eleventh feature of the present invention relates to the tenth feature of the present invention, wherein the data rate determination unit determines whether the average value exceeds a preset second data rate threshold, and transmits the transmission. The gist is to transmit an increase request for increasing the communication band to the base station controller when the data rate determination unit determines that the average value exceeds the second data rate threshold.

  A twelfth feature of the present invention relates to the tenth feature of the present invention, and is a buffer unit for storing data that has not been transmitted to the wireless communication terminal, and data of the data stored in the buffer unit. A buffer determination unit that determines whether or not the amount exceeds a preset buffer threshold, and the transmission unit is determined by the buffer determination unit that the amount of data exceeds the buffer threshold, and The gist is to transmit the decrease request to the base station controller when the data rate determination unit determines that the average value does not exceed the first data rate threshold.

  According to a thirteenth feature of the present invention, an average value of data rate information indicating an expected value of a downlink data rate estimated based on a reception state of a wireless communication terminal exceeds a preset first data rate threshold. When the sub-threshold notification indicating that there is no threshold is received from the radio base station and the sub-threshold notification is received in the receiving step, the sub-threshold notification is executed between the radio communication terminal and the communication destination device of the radio communication terminal It is a communication control method comprising: a step of determining to reduce a communication band assigned to a communication to be performed; and a step of notifying the communication destination device of the communication band determined in the determining step .

  The fourteenth feature of the present invention is the step of receiving from the radio base station a reduction request for reducing the communication band allocated to communication executed between a radio communication terminal and a communication destination device of the radio communication terminal; Communication control comprising: determining that the communication band is to be decreased when receiving the decrease request in the receiving step; and notifying the communication destination apparatus of the communication band determined in the determining step The gist is the method.

  According to the present invention, in data communication corresponding to QoS control, when a wireless communication environment deteriorates, a mobile communication system and base station control capable of avoiding overflow of data stored in a buffer in the wireless base station An apparatus, a radio base station, and a communication control method can be provided.

  Next, first to fourth embodiments of the present invention will be described with reference to the drawings. In the descriptions of the drawings in the following first to fourth embodiments, the same or similar parts are denoted by the same or similar reference numerals.

[First Embodiment]
(1) Overall schematic configuration of mobile communication system:
FIG. 1 shows an overall schematic configuration of a mobile communication system including a radio base station and a base station controller (PCF) according to the present embodiment. The mobile communication system shown in FIG. 1 is a so-called third generation mobile communication system based on cdma2000. Data communication according to A is executed.

  As shown in FIG. 1, the mobile communication system includes wireless communication terminals 1 and 2, wireless base stations 3 and 4, PCF (Packet Control Function) 5, PDSN (Packet Data Serving Node) 6, and IP (Internet Protocol) network. 7 and a media server 8.

  The wireless communication terminals 1 and 2 have an IP-based voice call (IP phone) function and an IP-based TV phone (IP-TV phone) function. In the present embodiment, a case where a videophone is executed between the wireless communication terminals 1 and 2 and image data is transferred from the wireless communication terminal 2 to the wireless communication terminal 1 will be mainly described.

  The radio communication terminal 1 is located in a cell C1 configured by the radio base station 3. The wireless communication terminal 1 connects to the wireless base station 3 and executes wireless communication with the wireless base station 3.

  The radio communication terminal 2 is located in a cell C2 constituted by the radio base station 4. The wireless communication terminal 2 is connected to the wireless base station 4 and performs wireless communication with the wireless base station 4.

  The radio base stations 3 and 4 have a QoS control function. Specifically, when the wireless communication terminals 1 and 2 execute a real-time application, the wireless base stations 3 and 4 use the buffer unit 34 (see FIG. 2) to communicate with the wireless communication terminals 1 and 2. The data rate of the wireless communication executed in is maintained constant.

  Further, when the wireless communication terminals 1 and 2 execute a real-time application, the wireless base stations 3 and 4 communicate with each other in preference to the wireless communication terminals 1 and 2 over the other wireless communication terminals in the cells C1 and C2. Allocate bandwidth.

  Specifically, in the downlink direction, the radio base stations 3 and 4 assign time slots in preference to the radio communication terminals 1 and 2 over other radio communication terminals. In the uplink direction, the radio base stations 3 and 4 increase the transmission power of the radio communication terminals 1 and 2 as compared to other radio communication terminals.

  The PCF 5 has a function of controlling the radio base stations 3 and 4 and a function of terminating a radio packet. Further, the PCF 5 determines a QoS rate assigned to communication executed between the wireless communication terminals 1 and 2 according to the type of application.

  Here, the “QoS rate” means the value of each QoS parameter such as a communication band, delay, and fluctuation (jitter). In the present embodiment, a case will be described in which the communication band is mainly handled among the QoS parameters. As types of applications, applications having high real-time characteristics (for example, VoIP), applications that are affected by shaking (jitter) (for example, streaming), and applications that are not easily affected by delay (for example, Web browsing and email) )and so on.

  The PDSN 6 has a function of terminating an IP packet. Further, the PDSN 6 controls the transfer of data (for example, image data) transmitted and received between the wireless communication terminals 1 and 2 according to the QoS rate determined by the PCF 5.

  The media server 8 manages data transfer on the IP network 7 according to a predetermined protocol (for example, RTP (Realtime Transport Protocol)). The media server 8 controls the transfer of data transmitted and received between the wireless communication terminals 1 and 2 according to the QoS rate determined by the PCF 5.

(2) Configuration of radio base station:
Next, the configuration of the radio base stations 3 and 4 will be described with reference to FIG. 2 and FIG.

(2.1) Schematic configuration of radio base station:
FIG. 2 is a functional block configuration diagram of the radio base station 3. Since the radio base station 4 has the same configuration as that of the radio base station 3, the description of the configuration of the radio base station 4 is omitted. Hereinafter, portions related to the present invention will be mainly described.

  As shown in FIG. 2, the radio base station 3 includes an antenna 31, a radio communication unit 32, a communication I / F unit 33, a buffer unit 34, a control unit 35A, and a storage unit 36A.

  The radio communication unit 32 transmits / receives a radio signal according to CDMA to / from the radio communication terminal 1 via the antenna 31. In addition, the wireless communication unit 32 performs conversion between the wireless signal and the baseband signal, and transmits / receives the baseband signal to / from the control unit 35A.

  The communication I / F unit 33 functions as an interface with the PCF 5.

  The buffer unit 34 temporarily stores data in order to maintain a constant data rate of data transmitted / received to / from the wireless communication terminal 1 subject to QoS control. The downlink data stored in the buffer unit 34 is deleted from the buffer unit 34 when transmission to the wireless communication terminal 1 is completed. The uplink data stored in the buffer unit 34 is deleted from the buffer unit 34 when transmission to the PCF 5 is completed. Hereinafter, the storage capacity allocated for data transmission to the wireless communication terminal 1 is referred to as a “transmission buffer”.

  The control unit 35A controls various functions that the wireless base station 3 has. More detailed functional blocks of the control unit 35A will be described later.

  The storage unit 36A stores various information used for control and the like in the radio base station 3. More detailed functional blocks of the storage unit 36A will be described later.

(2.2) Detailed configuration of control unit and storage unit:
FIG. 3 is a functional block configuration diagram showing a detailed configuration of the control unit 35A and the storage unit 36A shown in FIG. As illustrated in FIG. 3, the control unit 35 </ b> A includes a buffer determination unit 351 and a QoS control unit 352. The storage unit 36A includes a buffer threshold value storage unit 361.

  The buffer determination unit 351 determines whether or not the amount of data in the transmission buffer exceeds the buffer threshold value stored in the buffer threshold value storage unit 361. In the present embodiment, the buffer determination unit 351 compares the ratio of the storage capacity in which data is actually stored out of the total storage capacity of the transmission buffer (hereinafter referred to as “buffer capacity”) with the buffer threshold. And

  The QoS control unit 352 executes the above-described QoS control.

(3) Configuration of base station controller (PCF):
Next, the configuration of the PCF 5 will be described with reference to FIGS.

(3.1) Schematic configuration of base station controller (PCF):
FIG. 4 is a functional block configuration diagram of the PCF 5. As illustrated in FIG. 4, the PCF 5 includes a communication I / F unit 51, a communication I / F unit 52, a control unit 53, and a storage unit 54.

  The communication I / F unit 51 functions as an interface with the radio base stations 3 and 4. The communication I / F unit 52 functions as an interface with the PDSN 6.

  The control unit 53 controls various functions that the PCF 5 has. More detailed functional blocks of the control unit 53 will be described later.

  The storage unit 54 stores various information used for control in the PCF 5 and the like. More detailed functional blocks of the storage unit 54 will be described later.

(3.2) Detailed configuration of control unit and storage unit:
FIG. 5 is a functional block configuration diagram showing a detailed configuration of the control unit 53 and the storage unit 54 shown in FIG. As illustrated in FIG. 5, the control unit 53 includes a QoS rate determination unit 531, a QoS rate notification unit 532, and a QoS control unit 533. The storage unit 54 includes a QoS rate table storage unit 541.

  The QoS rate determination unit 531 performs communication performed between the wireless communication terminals 1 and 2 based on the transmission buffer of the wireless base stations 3 and 4 and the QoS rate table stored in advance in the QoS rate table storage unit 541. Determine the QoS rate to allocate.

  The QoS rate notification unit 532 notifies the QoS rate determined by the QoS rate determination unit 531 to the wireless communication terminals 1 and 2, the wireless base stations 3 and 4, the PDSN 6, the media server 8, and the like.

  The QoS control unit 533 performs QoS control according to the QoS rate determined by the QoS rate determination unit 531.

(3.3) Configuration of QoS rate table:
FIG. 6 is a diagram showing the configuration of the QoS rate table stored in the QoS rate table storage unit 541 shown in FIG. As illustrated in FIG. 6, the QoS rate table storage unit 541 includes a QoS rate table in which a QoS rate identifier (Flow Profile ID), a QoS rate type, a QoS rate content, and a buffer capacity of a transmission buffer are associated with each other. Remember.

  The QoS rate identifier (Flow Profile ID) is an identifier (ID) that uniquely identifies the QoS rate.

  Three types of QoS rates, “high”, “medium”, and “low”, are defined according to the level of the QoS rate (here, the communication band).

  The content of the QoS rate includes an application name (here, interactive conversation video (Conversational Interactive Video)) and communication band information (48 kbps, 40 kbps, 24 kbps).

  As for the buffer capacity of the transmission buffer, buffer capacity ranges (0-29%, 30-59%, 60%-) are defined for each QoS rate identifier (Flow Profile ID).

(4) Operation of mobile communication system:
Next, operations of the mobile communication system described above will be described with reference to FIGS.

(4.1) Overview of operation of radio base station and base station controller (PCF):
FIG. 7 is a flowchart showing an outline of operations of the radio base station 3 and the PCF 5. Here, the operation when the QoS rate is decreased will be described.

  In step S11, the PCF 5 determines whether or not the wireless communication terminals 1 and 2 are performing communication involving QoS control. When the wireless communication terminals 1 and 2 are performing communication involving QoS control, the process proceeds to step S12.

  In step S12, the radio base station 3 determines whether or not the buffer capacity of the transmission buffer exceeds a threshold value. If it is determined that the buffer capacity of the transmission buffer exceeds the threshold, the process proceeds to step S13.

  In step S13, the PCF 5 determines whether or not the QoS rate assigned to the wireless communication terminals 1 and 2 is the minimum value (QoS rate “low”). If the QoS rate assigned to the wireless communication terminals 1 and 2 is not the minimum value, the process proceeds to step S14.

  In step S14, the PCF 5 determines to decrease the QoS rate by one step.

(4.2) Operation of the entire mobile communication system (Pattern 1):
FIG. 8 is a sequence diagram showing an operation sequence of the entire mobile communication system described above. Here, a case will be described in which image data is transferred from the wireless communication terminal 2 to the wireless communication terminal 1 during a videophone call between the wireless communication terminals 1 and 2. In addition, it is assumed that the wireless communication environment between the wireless communication terminal 1 and the wireless base station 3 has deteriorated. In FIG. 8, PDSN 6 is omitted.

  In steps S101a to S101e, a QoS establishment operation is executed. Specifically, between the wireless communication terminal 1 and the wireless base station 3, between the wireless base station 3 and the PCF 5, between the PCF 5 and the media server 8, between the media server 8 and the wireless base station 4, and A QoS establishment operation (QoS rate “high”) is performed between the radio base station 4 and the radio communication terminal 2.

  In step S102, the wireless communication terminal 2 transmits image data to the wireless base station 4 via the wireless section. Since the wireless communication environment between the wireless communication terminal 2 and the wireless base station 4 is good, the wireless communication terminal 2 transmits image data to the wireless base station 4 at the QoS rate “high” set in step S101e. To do.

  In step S103 to step S105, the wireless base station 4 transfers the image data to the wireless base station 3 via the media server 8 and the PCF 5.

  In step S106, the radio base station 3 transmits the image data to the radio communication terminal 1 via the radio section. Since the wireless communication environment between the wireless communication terminal 1 and the wireless base station 3 has deteriorated, wireless communication at the QoS rate “high” set in step S101a is not executed. For this reason, the data rate of the data transmitted from the radio base station 3 to the radio communication terminal 1 is greatly reduced as compared with Steps S102 to S105.

  In step S107, the radio base station 3 determines whether the buffer capacity of the transmission buffer exceeds a threshold A (for example, 30%) (30% or more). If it is determined that the buffer capacity of the transmission buffer exceeds the threshold A, the process proceeds to step S108.

  In step S108, the radio base station 3 transmits to the PCF 5 a buffer threshold super notification indicating that the buffer capacity of the transmission buffer exceeds the threshold A.

  In step S109, the PCF 5 determines to lower the QoS rate by one step and change the QoS rate to “medium”.

  In step S110a to step S110e, the PCF 5 executes a QoS rate change process. Specifically, the PCF 5 notifies the wireless communication terminal 1, the wireless base station 3, the media server 8, the wireless base station 4, and the wireless communication terminal 2 that the QoS rate is changed to “medium”.

  In step S111, the wireless communication terminal 2 transmits the image data to the wireless base station 4 at the QoS rate “medium” changed in step S110e.

  In step S112 to step S114, the wireless base station 4 transfers the image data to the wireless base station 3 via the media server 8 and the PCF 5.

  In step S115, the radio base station 3 transmits image data to the radio communication terminal 1 at the QoS rate “medium” set in step S110a. In step S115, the data rate of data transmitted from the radio base station 3 to the radio communication terminal 1 is equivalent to that in steps S111 to S114.

  In step S116, the radio base station 3 determines whether or not the QoS rate is the highest value (QoS rate “high”). If the QoS rate is not the highest value, the process proceeds to step S117.

  In step S117, the radio base station 3 determines whether or not the buffer capacity of the transmission buffer exceeds a threshold value B (for example, 29%) (29% or less) in a certain period. If the buffer capacity of the transmission buffer does not exceed the threshold B for a certain period (29% or less), the process proceeds to step S118.

  In step S118, the radio base station 3 determines whether or not there is room for assigning a high QoS rate (communication band) to the radio communication terminal 1. If there is room to allocate a high QoS rate to the wireless communication terminal 1, the process proceeds to step S119.

  In step S119, the radio base station 3 transmits to the PCF 5 a buffer lower threshold notification indicating that the buffer capacity of the transmission buffer does not exceed the threshold B.

  In step S120, the PCF 5 determines to increase the QoS rate by one level and change the QoS rate to “high”.

  In step S121a to step S121e, the PCF 5 executes a QoS rate change process. Specifically, the PCF 5 notifies the radio communication terminal 1, the radio base station 3, the media server 8, the radio base station 4, and the radio communication terminal 2 that the QoS rate is changed to “high”.

(4.3) Overall operation of mobile communication system (Pattern 2):
FIG. 9 is a sequence diagram showing an operation sequence of the entire mobile communication system described above. Here, operations different from those in FIG. 8 will be mainly described, and redundant descriptions will be omitted.

  In steps S201a to S201e, the QoS establishment operation (QoS rate “high”) is executed.

  In steps S202 to S206, the wireless communication terminal 2 transfers image data to the wireless communication terminal 1.

  In step S207, the radio base station 3 determines whether the buffer capacity of the transmission buffer exceeds a threshold A (for example, 30%) (30% or more). If the buffer capacity of the transmission buffer exceeds the threshold A (30% or more), the process proceeds to step S208.

  In step S208, the radio base station 3 determines to lower the QoS rate by one step and change the QoS rate to “medium”.

  In step S209, the radio base station 3 transmits to the PCF 5 a QoS rate decrease request for reducing the QoS rate by one step.

  In steps S210a to S210d, the PCF 5 determines to change the QoS rate to “medium” and executes the QoS rate changing process. Specifically, the PCF 5 notifies the wireless communication terminal 1, the media server 8, the wireless base station 4, and the wireless communication terminal 2 that the QoS rate is changed to “medium”.

  In steps S <b> 211 to S <b> 215, the wireless communication terminal 2 transfers the image data to the wireless communication terminal 1 at the QoS rate “medium”.

  In step S216, the radio base station 3 determines whether or not the QoS rate is the highest value (QoS rate “high”).

  If the QoS rate is not the maximum value, in step S217, the radio base station 3 determines whether or not the buffer capacity of the transmission buffer exceeds the threshold value B (29% or less) in a certain period.

  If the buffer capacity of the transmission buffer does not exceed the threshold B for a certain period (29% or less), whether or not the radio base station 3 has a room to allocate a high QoS rate to the radio communication terminal 1 in step S218. Determine whether.

  If there is room to allocate a high QoS rate to the wireless communication terminal 1, in step S219, the wireless base station 3 determines to increase the QoS rate by one step and change it to the QoS rate “high”.

  In step S220, the radio base station 3 transmits a QoS rate increase request for increasing the QoS rate by one step to the PCF 5.

  In steps S221a to S221d, the PCF 5 determines to change the QoS rate to “high” and executes the QoS rate changing process. Specifically, the PCF 5 notifies the wireless communication terminal 1, the media server 8, the wireless base station 4, and the wireless communication terminal 2 that the QoS rate is changed to “high”.

(Action / Effect)
When the buffer capacity of the transmission buffer exceeds the threshold A, the radio base station 3 transmits a buffer threshold super notification or a QoS rate reduction request to the PCF 5. When the PCF 5 receives a buffer threshold super notification or a QoS rate decrease request from the radio base station 3, the PCF 5 determines to decrease the QoS rate and notifies the determined radio communication terminal 2 of the determined QoS rate.

  As a result, even if the wireless communication environment between the wireless communication terminal 1 and the wireless base station 3 deteriorates, the wireless communication terminal 2 transmits before the data stored in the buffer unit 34 of the wireless base station 3 overflows. The data rate of data to be reduced can be reduced. Therefore, the data stored in the buffer unit 34 in the radio base station 3 can be prevented from overflowing.

  In addition, when the buffer capacity of the transmission buffer does not exceed the threshold B for a certain period, the radio base station 3 transmits a buffer threshold lowering notification or a QoS rate increase request to the PCF 5. The PCF 5 determines to increase the QoS rate when receiving a buffer threshold notification or a QoS rate increase request from the radio base station 3.

  Therefore, since the PCF 5 can dynamically determine the QoS rate according to the buffer capacity of the transmission buffer, it is possible to realize a QoS rate change control that follows changes in the wireless communication environment.

  Further, when the PCF 5 receives a buffer threshold super notification or a QoS rate decrease request from the radio base station 3, the PCF 5 determines to decrease the QoS rate and notifies the radio communication terminal 1 of the determined QoS rate. Therefore, when the wireless communication environment between the wireless communication terminal 1 and the wireless base station 3 deteriorates, it is possible to prevent the uplink data buffer from overflowing in the wireless communication terminal 1.

[Second Embodiment]
In the first embodiment described above, the configuration in which the PCF 5 changes the QoS rate based on the buffer capacity of the transmission buffer has been described. In the present embodiment, a configuration in which the PCF 5 changes the QoS rate based on the reception state of the wireless communication terminal 1 will be described. In the present embodiment, differences from the first embodiment described above will be mainly described, and duplicate descriptions will be omitted.

(1) DRC notification by the wireless communication terminal:
In the present embodiment, DRC (data rate control bit) notified from the wireless communication terminal 1 is used for QoS rate change control.

  The wireless communication terminal 1 measures a carrier-to-interference power ratio (CIR) of a pilot signal as a downlink reception state from the wireless base station 3.

  The wireless communication terminal 1 estimates the reception state at the next reception timing from the CIR variation, and is expected from the estimated reception state “maximum data rate that can be received at a predetermined error rate (eg, 1%) or less”. To the radio base station 3 as DRC. As shown in FIG. 10, there are 15 types of DRCs 0-14.

(2) Configuration of radio base station:
As shown in FIG. 11, the radio base station 3 according to the present embodiment differs from the first embodiment described above in the configuration of the control unit 35B and the storage unit 36B.

  The control unit 35B illustrated in FIG. 11 includes a DRC determination unit 353 and a QoS control unit 352. The storage unit 36B includes a DRC threshold storage unit 362.

  The DRC determination unit 353 determines whether or not the average value of DRC notified from the wireless communication terminal 1 over a predetermined time (for example, 5 seconds) exceeds the DRC threshold stored in the DRC threshold storage unit 362.

  The QoS control unit 352 executes the above-described QoS control.

(3) Configuration of base station controller (PCF):
The PCF 5 according to the present embodiment is different from the first embodiment described above in that it stores a QoS rate table as shown in FIG.

  As illustrated in FIG. 12, the PCF 5 stores a QoS rate table in which a QoS rate identifier (Flow Profile ID), a QoS rate type, a QoS rate content, and a minimum DRC (DRC threshold) are associated with each other. The minimum DRC (DRC threshold) is predetermined for each QoS rate identifier (Flow Profile ID).

(4) Operation of mobile communication system:
Next, operations of the mobile communication system including the radio base station and the base station controller (PCF) according to the present embodiment will be described with reference to FIGS.

(4.1) Overview of operation of radio base station and base station controller (PCF):
FIG. 13 is a flowchart showing an outline of operations of the radio base station 3 and the PCF 5 according to this embodiment. Here, the operation when the QoS rate is decreased will be described.

  In step S21, the PCF 5 determines whether or not the wireless communication terminals 1 and 2 are executing communication involving QoS control. When the wireless communication terminals 1 and 2 are performing communication involving QoS control, the process proceeds to step S22.

  In step S22, the radio base station 3 determines whether or not the DRC predetermined time average value exceeds a threshold value. When it is determined that the DRC predetermined time average value is equal to or less than the threshold value, the process proceeds to step S23.

  In step S23, the PCF 5 determines whether or not the QoS rate assigned to the wireless communication terminals 1 and 2 is the minimum value (QoS rate “low”). If the QoS rate assigned to the wireless communication terminals 1 and 2 is not the minimum value, the process proceeds to step S24.

  In step S24, the PCF 5 determines to decrease the QoS rate by one step.

(4.2) Operation of the entire mobile communication system (Pattern 1):
FIG. 14 is a sequence diagram showing an operation sequence of the entire mobile communication system including the radio base station and the base station controller (PCF) according to the present embodiment.

  In steps S301a to S301e, the QoS establishment operation (QoS rate “high”) is executed.

  In steps S302 to S306, the wireless communication terminal 2 transfers image data to the wireless communication terminal 1.

  In step S307, the radio base station 3 determines whether or not the predetermined time average value of DRC is equal to or less than a threshold value C (for example, DRC “7”) (predicted speed lower than the speed corresponding to DRC “7”). . When it is determined that the DRC predetermined time average value is equal to or less than the threshold value C, the process proceeds to step S308.

  In step S308, the radio base station 3 transmits to the PCF 5 a DRC threshold value lowering notification indicating that the DRC predetermined time average value is equal to or less than the threshold value C.

  In step S309, the radio base station 3 determines to lower the QoS rate by one step and change it to the QoS rate “medium”.

  In step S310a to step S310e, the PCF 5 executes a QoS rate change process. Specifically, the PCF 5 notifies the wireless communication terminal 1, the wireless base station 3, the media server 8, the wireless base station 4, and the wireless communication terminal 2 that the QoS rate is changed to “medium”.

  In steps S 311 to S 315, the wireless communication terminal 2 transfers the image data to the wireless communication terminal 1 at the QoS rate “medium”.

  In step S316, the radio base station 3 determines whether or not the QoS rate is the highest value (QoS rate “high”).

  If the QoS rate is not the highest value, in step S317, the radio base station 3 determines whether the predetermined time average value of DRC exceeds a threshold value D (for example, DRC “5”) (a speed corresponding to DRC “5”). Low speed).

  When the predetermined time average value of DRC exceeds the threshold value D, in step S318, the radio base station 3 determines whether or not there is room to allocate a high QoS rate to the radio communication terminal 1.

  If there is room to allocate a high QoS rate to the wireless communication terminal 1, in step S319, the wireless base station 3 transmits a threshold value super-notification indicating that the predetermined time average value of DRC exceeds the threshold value D to the PCF 5. To do.

  In step S320, the PCF 5 decides to increase the QoS rate by one level and change the QoS rate to “high”.

  In step S321a to step S321e, the PCF 5 executes a QoS rate change process. Specifically, the PCF 5 notifies the radio communication terminal 1, the radio base station 3, the media server 8, the radio base station 4, and the radio communication terminal 2 that the QoS rate is changed to “high”.

(4.3) Overall operation of mobile communication system (Pattern 2):
FIG. 15 is a sequence diagram showing an operation sequence of the entire mobile communication system including the radio base station and the base station controller (PCF) according to the present embodiment. Here, operations different from those in FIG. 14 will be mainly described, and redundant descriptions will be omitted.

  In steps S401a to S401e, a QoS establishment operation (QoS rate “high”) is executed.

  In steps S402 to S406, the wireless communication terminal 2 transfers the image data to the wireless communication terminal 1.

  In step S407, the radio base station 3 determines whether or not the predetermined time average value of DRC is equal to or lower than a threshold value C (for example, DRC “7”) (a speed lower than the speed corresponding to DRC “7”).

  If the predetermined time average value of DRC is equal to or less than the threshold value C, in step S408, the radio base station 3 determines to lower the QoS rate by one step and to change the QoS rate to “medium”.

  In step S409, the radio base station 3 transmits to the PCF 5 a QoS rate decrease request for reducing the QoS rate by one step.

  In step S410a to step S410d, the PCF 5 executes a QoS rate change process. Specifically, the PCF 5 notifies the wireless communication terminal 1, the media server 8, the wireless base station 4, and the wireless communication terminal 2 that the QoS rate is changed to “medium”.

  In steps S411 to S415, the wireless communication terminal 2 transfers the image data to the wireless communication terminal 1 at the QoS rate “medium”.

  In step S416, the radio base station 3 determines whether or not the QoS rate is the highest value (QoS rate “high”).

  When the QoS rate is not the highest value, in step S417, the radio base station 3 determines whether the predetermined time average value of DRC exceeds a threshold value D (for example, DRC “5”) (a speed corresponding to DRC “5”). High speed).

  When the predetermined time average value of DRC exceeds the threshold value D, in step S418, the radio base station 3 determines whether or not there is room to allocate a high QoS rate to the radio communication terminal 1.

  If there is room to allocate a high QoS rate to the radio communication terminal 1, in step S419, the radio base station 3 determines to increase the QoS rate by one step and change the QoS rate to “high”.

  In step S420, the radio base station 3 transmits a QoS rate increase request for increasing the QoS rate by one step to the PCF 5.

  In step S421a to step S421d, the PCF 5 executes a QoS rate change process. Specifically, the PCF 5 notifies the wireless communication terminal 1, the media server 8, the wireless base station 4, and the wireless communication terminal 2 that the QoS rate is changed to “high”.

(Action / Effect)
When the average value of DRC for a predetermined time is equal to or less than the threshold C, the radio base station 3 transmits a DRC threshold lowering notification or a QoS rate reduction request to the PCF 5. When the PCF 5 receives a DRC threshold lowering notification or a QoS rate reduction request from the radio base station 3, the PCF 5 decides to reduce the QoS rate, and notifies the transmission side radio communication terminal 2 of the decided QoS rate.

  As a result, even if the wireless communication environment between the wireless communication terminal 1 and the wireless base station 3 deteriorates, the wireless communication terminal 2 transmits before the data stored in the buffer unit 34 of the wireless base station 3 overflows. The data rate of data to be reduced can be reduced. Therefore, the data stored in the buffer unit 34 in the radio base station 3 can be prevented from overflowing.

  When the predetermined time average value of DRC exceeds the threshold value D, the radio base station 3 transmits a DRC threshold value super notification or a QoS rate increase request to the PCF 5. The PCF 5 determines to increase the QoS rate when receiving the DRC threshold value super notification or the QoS rate increase request from the radio base station 3.

  Accordingly, since the PCF 5 can dynamically determine the QoS rate according to the DRC predetermined time average value, it is possible to realize the QoS rate change control following the change in the wireless communication environment.

  Further, when the PCF 5 receives a DRC threshold lowering notification or a QoS rate reduction request from the radio base station 3, the PCF 5 decides to reduce the QoS rate and notifies the radio communication terminal 1 of the decided QoS rate. Therefore, when the wireless communication environment between the wireless communication terminal 1 and the wireless base station 3 deteriorates, it is possible to prevent the uplink data buffer from overflowing in the wireless communication terminal 1.

[Third Embodiment]
In the present embodiment, a configuration will be described in which the PCF 5 changes the QoS rate using both the buffer capacity of the transmission buffer and the DRC predetermined time average value. In the present embodiment, differences from the first and second embodiments described above will be mainly described, and overlapping descriptions will be omitted.

(1) Configuration of radio base station:
As shown in FIG. 16, the radio base station 3 according to the present embodiment is different from the first and second embodiments described above in the configuration of the control unit 35C and the storage unit 36C.

  The control unit 35C includes a buffer determination unit 351, a DRC determination unit 353, and a QoS control unit 352. The storage unit 36C includes a buffer threshold storage unit 361 and a DRC threshold storage unit 362.

  The buffer determination unit 351 determines whether or not the buffer capacity of the transmission buffer has exceeded the buffer threshold value stored in the buffer threshold value storage unit 361.

  The DRC determination unit 353 determines whether or not the DRC predetermined time average value exceeds the DRC threshold stored in the DRC threshold storage unit 362.

  The QoS control unit 352 executes the above-described QoS control.

(2) Operation of the radio base station and base station controller (PCF):
FIG. 17 is a sequence diagram showing an operation sequence of the radio base station 3 and the PCF 5 according to this embodiment. In FIG. 17, the operation sequence for the media server 8, the wireless base station 4, and the wireless communication terminal 2 is omitted.

  In steps S501a and S501b, a QoS establishment operation (QoS rate “high”) is executed.

  In step S502, the radio base station 3 determines whether or not the buffer capacity of the transmission buffer exceeds the threshold A.

  When the buffer capacity of the transmission buffer exceeds the threshold A, the radio base station 3 determines whether or not the DRC predetermined time average value is equal to or less than the threshold C in step S503.

  If the predetermined time average value of DRC is equal to or less than the threshold value C, in step S504, the radio base station 3 determines to lower the QoS rate by one step and change the QoS rate to “medium”.

  In step S505, the radio base station 3 transmits to the PCF 5 a QoS rate reduction request for reducing the QoS rate by one step.

  In step S506, the PCF 5 determines to change the QoS rate to “medium” and executes the QoS rate changing process. Specifically, the PCF 5 notifies the wireless communication terminal 1, the media server 8, the wireless base station 4, and the wireless communication terminal 2 that the QoS rate is changed to “medium”.

  In step S507, the radio base station 3 determines whether or not the QoS rate is the highest value (QoS rate “high”).

  If the QoS rate is not the maximum value, in step S507, the radio base station 3 determines whether or not the buffer capacity of the transmission buffer exceeds the threshold value B in a certain period.

  When the buffer capacity of the transmission buffer does not exceed the threshold value B in a certain period, the radio base station 3 determines whether or not the DRC predetermined time average value exceeds the threshold value D in step S509.

  When the predetermined time average value of DRC exceeds the threshold value D, in step S510, the radio base station 3 determines whether or not there is room to allocate a high QoS rate to the radio communication terminal 1.

  If there is room to allocate a high QoS rate to the radio communication terminal 1, in step S511, the radio base station 3 determines to increase the QoS rate by one step and change the QoS rate to “high”.

  In step S512, the radio base station 3 transmits to the PCF 5 a QoS rate increase request for increasing the QoS rate by one step.

  In step S513, the PCF 5 executes a QoS rate change process. Specifically, the PCF 5 notifies the wireless communication terminal 1, the media server 8, the wireless base station 4, and the wireless communication terminal 2 that the QoS rate is changed to “high”.

(Action / Effect)
When it is determined that the buffer capacity of the transmission buffer exceeds the threshold A and the average value of DRC is equal to or less than the threshold C, the radio base station 3 transmits a QoS rate reduction request to the PCF 5. That is, even if the buffer capacity of the transmission buffer exceeds the threshold A, if the DRC predetermined time average value is not equal to or less than the threshold C, the QoS rate reduction request is not transmitted to the PCF 5.

  Therefore, if the wireless communication environment tends to improve, the QoS rate is not reduced, so that it is possible to prevent the QoS rate from being reduced unnecessarily. That is, if the wireless communication environment tends to improve, the current QoS rate is maintained, so that the data rate of data transferred between the wireless communication terminals 1 and 2 can be maintained well.

[Fourth Embodiment]
In the present embodiment, the configuration in which the PCF 5 changes the QoS rate based on whether or not an instantaneous communication interruption has occurred in the wireless communication terminal 1 in addition to the buffer capacity of the transmission buffer and the predetermined time average value of the DRC. Will be described. In the present embodiment, differences from the above-described first to third embodiments will be mainly described, and overlapping descriptions will be omitted.

(1) Configuration of radio base station:
As illustrated in FIG. 18, the radio base station 3 according to the present embodiment is different from the third embodiment described above in the configurations of the control unit 35D and the storage unit 36D.

  The control unit 35D includes a buffer determination unit 351, a DRC determination unit 353, a QoS control unit 352, and an instantaneous interruption determination unit 354. The storage unit 36C includes a buffer threshold storage unit 361 and a DRC threshold storage unit 362.

  The buffer determination unit 351 determines whether or not the buffer capacity of the transmission buffer has exceeded the buffer threshold value stored in the buffer threshold value storage unit 361.

  The DRC determination unit 353 determines whether or not the DRC predetermined time average value exceeds the DRC threshold stored in the DRC threshold storage unit 362.

  The QoS control unit 352 executes the above-described QoS control.

  The instantaneous interruption determination unit 354 determines whether or not an instantaneous communication interruption has occurred in the wireless communication terminal 1 based on the DRC.

(2) Communication interruption determination processing:
19 and 20 are diagrams for explaining the communication interruption determination processing by the instantaneous interruption determination unit 354.

  When the sudden drop in DRC as shown in FIG. 19 occurs immediately before the timing when the buffer capacity of the transmission buffer exceeds the threshold, the instantaneous interruption determination unit 354 causes the communication interruption in the wireless communication terminal 1 to occur. It is determined that it may have occurred.

  When it is determined that there is a possibility that an instantaneous communication interruption has occurred in the wireless communication terminal 1, the instantaneous interruption determination unit 354 immediately before the timing when the buffer capacity of the transmission buffer exceeds the threshold value, as illustrated in FIG. , It is determined whether or not the DRC lock has been temporarily turned off.

  When the DRC lock is temporarily turned off, the instantaneous interruption determination unit 354 determines that an instantaneous communication interruption has occurred in the wireless communication terminal 1.

  The DRC lock indicates a reception response to the DRC information transmitted from the wireless communication terminal 1, and is transmitted from the wireless base station 3 to the DRC transmitted from the wireless communication terminal 1 on a regular basis. is there. Therefore, if the DRC lock is temporarily turned off, transmission from the wireless communication terminal 1 is interrupted.

(3) Operation of radio base station and base station controller (PCF):
FIG. 21 is a sequence diagram showing an operation sequence of the radio base station 3 and the PCF 5 according to this embodiment. In FIG. 17, the operation sequence for the media server 8, the wireless base station 4, and the wireless communication terminal 2 is omitted.

  In steps S601a and S601b, a QoS establishment operation (QoS rate “high”) is executed.

  In step S602, the radio base station 3 determines whether or not the buffer capacity of the transmission buffer exceeds the threshold A.

  When the buffer capacity of the transmission buffer exceeds the threshold value A, in step S603, the radio base station 3 executes the communication interruption determination process described above.

  In step S604, the radio base station 3 determines whether or not there is a communication interruption in the radio communication terminal 1 according to the result of step S603. When it is determined that no communication interruption has occurred in the wireless communication terminal 1, the process proceeds to step S605.

  In step S605, the radio base station 3 determines to lower the QoS rate by one step and change the QoS rate to “medium”.

  In step S606, the radio base station 3 transmits to the PCF 5 a QoS rate decrease request for reducing the QoS rate by one step.

  In step S607, the PCF 5 determines to change the QoS rate to “medium” and executes the QoS rate changing process. Specifically, the PCF 5 notifies the wireless communication terminal 1, the media server 8, the wireless base station 4, and the wireless communication terminal 2 that the QoS rate is changed to “medium”.

  The subsequent processing in steps S608 to 614 is the same as the processing in steps S507 to S513 in FIG.

(Action / Effect)
When it is determined that the buffer capacity of the transmission buffer has exceeded the threshold value A due to an instantaneous communication interruption, the radio base station 3 cancels transmission of the QoS rate reduction request to the PCF 5. That is, when the buffer capacity of the transmission buffer exceeds the threshold due to an instantaneous communication interruption, the QoS rate is not decreased because the wireless communication environment is temporarily deteriorated.

  Therefore, when the buffer capacity of the transmission buffer exceeds the threshold due to an instantaneous communication interruption, the current QoS rate can be maintained, and the data rate of data transferred between the wireless communication terminals 1 and 2 can be favorably maintained.

[Other Embodiments]
As described above, the present invention has been described according to the first to fourth embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the above-described first to fourth embodiments, the case where communication is performed between the wireless communication terminals 1 and 2 has been described. May be configured to download.

  In the third and fourth embodiments described above, the case where the QoS rate decrease request and the QoS rate increase request are transmitted from the radio base station 3 to the PCF 5 has been described. However, a buffer threshold super notification (or DRC threshold low notification) and a buffer threshold super notification (or DRC threshold super notification) may be transmitted from the radio base station 3 to the PCF 5.

  In the above-described embodiment, the configuration in which the PCF 5 performs QoS rate change control has been described. However, the PDSN 6 may be configured to execute QoS rate change control.

  In addition, as the threshold for changing the QoS rate, individual thresholds may be used for each increase / decrease, and the increase / decrease may be controlled by one threshold (for each stage).

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters in the scope of claims reasonable from this disclosure.

1 is an overall schematic configuration diagram of a mobile communication system including a radio base station and a base station controller (PCF) according to a first embodiment of the present invention. It is a functional block block diagram of the wireless base station which concerns on 1st Embodiment of this invention. It is a functional block block diagram which shows the detailed structure of the control part of FIG. 2, and a memory | storage part. It is a functional block block diagram of the base station control apparatus (PCF) which concerns on 1st Embodiment of this invention. It is a functional block block diagram which shows the detailed structure of the control part of FIG. 4, and a memory | storage part. It is a block diagram of the QoS rate table which the base station control apparatus (PCF) which concerns on 1st Embodiment of this invention memorize | stores. It is a flowchart which shows the operation | movement outline | summary of the radio base station and base station control apparatus (PCF) which concern on 1st Embodiment of this invention. It is a sequence diagram which shows the whole operation | movement of the mobile communication system containing the wireless base station and base station control apparatus (PCF) which concern on 1st Embodiment of this invention (pattern 1). FIG. 2 is a sequence diagram showing an overall operation of a mobile communication system including a radio base station and a base station controller (PCF) according to the first embodiment of the present invention (Pattern 2). It is a figure for demonstrating DRC which the radio base station which concerns on 2nd Embodiment of this invention handles. It is a functional block block diagram which shows the detailed structure of the control part and memory | storage part which are provided in the wireless base station which concerns on 2nd Embodiment of this invention. It is a block diagram of the QoS rate table which the base station control apparatus (PCF) which concerns on 2nd Embodiment of this invention memorize | stores. It is a flowchart which shows the operation | movement outline | summary of the radio base station and base station control apparatus (PCF) which concern on 2nd Embodiment of this invention. It is a sequence diagram which shows the whole operation | movement of the mobile communication system containing the wireless base station and base station control apparatus (PCF) which concern on 2nd Embodiment of this invention (pattern 1). It is a sequence diagram which shows the whole operation | movement of the mobile communication system containing the wireless base station and base station control apparatus (PCF) which concern on 2nd Embodiment of this invention (pattern 2). It is a functional block block diagram which shows the detailed structure of the control part and memory | storage part which are provided in the wireless base station which concerns on 3rd Embodiment of this invention. It is a sequence diagram which shows the operation | movement of a part of mobile communication system containing the wireless base station and base station control apparatus (PCF) which concern on 3rd Embodiment of this invention. It is a functional block block diagram which shows the detailed structure of the control part and memory | storage part which are provided in the wireless base station which concerns on 4th Embodiment of this invention. It is a wave form diagram for demonstrating the instantaneous interruption determination operation | movement by the wireless base station which concerns on 4th Embodiment of this invention (the 1). It is a wave form diagram for demonstrating the instantaneous interruption determination operation | movement by the wireless base station which concerns on 4th Embodiment of this invention (the 2). It is a sequence diagram which shows the operation | movement of a part of mobile communication system containing the radio base station and base station control apparatus (PCF) which concern on 4th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 2 ... Wireless communication terminal, 3, 4 ... Wireless base station, 5 ... PCF, 6 ... PDSN, 7 ... IP network, 8 ... Media server, 31 ... Antenna, 32 ... Wireless communication part, 33 ... Communication I / F 34, buffer unit, 35A to 35D ... control unit, 36A to 36D ... storage unit, 51, 52 ... communication I / F unit, 53 ... control unit, 54 ... storage unit, 351 ... buffer determination unit, 352 ... QoS Control unit, 353 ... DRC determination unit, 354 ... instantaneous interruption determination unit, 361 ... buffer threshold storage unit, 362 ... DRC threshold storage unit, 531 ... QoS rate determination unit, 532 ... QoS rate notification unit, 533 ... QoS control unit, 541 ... QoS rate table storage unit

Claims (14)

A mobile communication system comprising a radio base station and a base station controller for controlling the radio base station,
The radio base station is
A receiving unit that receives from the wireless communication terminal data rate information indicating an expected value of a downlink data rate estimated based on a reception state of the wireless communication terminal;
A data rate determination unit that determines whether an average value of the data rate information in a certain period exceeds a preset data rate threshold;
When the average value is determined not to exceed the data rate threshold by the data rate determination unit, a sub-threshold notification indicating that the average value does not exceed the data rate threshold is transmitted to the base station controller. And a transmission unit
The base station controller is
A receiving unit that receives the subthreshold notification from the radio base station;
A determination unit that determines to reduce a communication band assigned to communication performed between the wireless communication terminal and a communication destination device of the wireless communication terminal when the receiving unit receives the sub-threshold notification;
A mobile communication system comprising: a notification unit that notifies the communication destination device of the communication band determined by the determination unit. A mobile communication system comprising a radio base station and a base station controller for controlling the radio base station,
The radio base station is
A receiving unit that receives from the wireless communication terminal data rate information indicating an expected value of a downlink data rate estimated based on a reception state of the wireless communication terminal;
A data rate determination unit that determines whether an average value of the data rate information in a certain period exceeds a preset data rate threshold;
When the data rate determination unit determines that the average value does not exceed the data rate threshold, a communication band assigned to communication performed between the wireless communication terminal and a communication destination device of the wireless communication terminal A transmission unit for transmitting a decrease request to decrease to the base station controller,
The base station controller is
A receiving unit for receiving the reduction request from the radio base station;
A determination unit that determines to decrease the communication band when the reception unit receives the decrease request;
A mobile communication system comprising: a notification unit that notifies the communication destination device of the communication band determined by the determination unit. Sub-threshold notification indicating that the average value of the data rate information indicating the expected value of the downlink data rate estimated based on the reception state of the wireless communication terminal does not exceed a preset first data rate threshold, A receiving unit for receiving from a radio base station;
A determination unit that determines to reduce a communication band assigned to communication performed between the wireless communication terminal and a communication destination device of the wireless communication terminal when the receiving unit receives the sub-threshold notification;
A base station control device comprising: a notification unit that notifies the communication destination device of the communication band determined by the determination unit. The reception unit receives a threshold value super notification indicating that the average value exceeds a preset second data rate threshold value from the radio base station,
The base station control apparatus according to claim 3, wherein the determination unit determines to increase the communication band when the reception unit receives the threshold value super notification. A receiving unit that receives a reduction request for reducing a communication band allocated to communication performed between a wireless communication terminal and a communication destination device of the wireless communication terminal from a wireless base station connected to the wireless communication terminal;
A determination unit that determines to decrease the communication band when the reception unit receives the decrease request;
A base station control device comprising: a notification unit that notifies the communication destination device of the communication band determined by the determination unit. The receiving unit receives an increase request for increasing the communication band from the radio base station,
The base station control apparatus according to claim 5, wherein the determination unit determines to increase the communication band when the reception unit receives the increase request. A receiving unit that receives from the wireless communication terminal data rate information indicating an expected value of a downlink data rate estimated based on a reception state of the wireless communication terminal;
A data rate determination unit that determines whether an average value of the data rate information for a certain period exceeds a preset first data rate threshold;
If the data rate determination unit determines that the average value does not exceed the first data rate threshold value, base station control performs sub-threshold notification indicating that the average value does not exceed the first data rate threshold value A radio base station comprising a transmission unit that transmits to a device. The data rate determination unit determines whether the average value exceeds a preset second data rate threshold;
When the average value exceeds the second data rate threshold value by the data rate determination unit, the transmission unit sends a threshold value super notification indicating that the average value exceeds the second data rate threshold value. The radio base station according to claim 7, which is transmitted to the base station control device. A buffer unit for storing data that has not been transmitted to the wireless communication terminal;
A buffer determination unit that determines whether the data amount of the data stored in the buffer unit exceeds a preset buffer threshold;
When the transmission unit determines that the amount of data has exceeded the buffer threshold by the buffer determination unit, and the data rate determination unit determines that the average value does not exceed the first data rate threshold The radio base station according to claim 7, wherein the subthreshold notification is transmitted to the base station control device. A receiving unit that receives from the wireless communication terminal data rate information indicating an expected value of a downlink data rate estimated based on a reception state of the wireless communication terminal;
A data rate determination unit that determines whether an average value of the data rate information for a certain period exceeds a preset first data rate threshold;
When the data rate determination unit determines that the average value does not exceed the data rate threshold, a communication band assigned to communication performed between the wireless communication terminal and a communication destination device of the wireless communication terminal A radio base station comprising: a transmission unit that transmits a decrease request to decrease to a base station controller. The data rate determination unit determines whether the average value exceeds a preset second data rate threshold;
The said transmission part transmits the increase request | requirement which increases the said communication band to the said base station control apparatus, when the said data rate determination part determines with the said average value exceeding the said 2nd data rate threshold value. The radio base station described. A buffer unit for storing data that has not been transmitted to the wireless communication terminal;
A buffer determination unit that determines whether the data amount of the data stored in the buffer unit exceeds a preset buffer threshold;
When the transmission unit determines that the amount of data has exceeded the buffer threshold by the buffer determination unit, and the data rate determination unit determines that the average value does not exceed the first data rate threshold The radio base station according to claim 10, wherein the decrease request is transmitted to the base station control device. Sub-threshold notification indicating that the average value of the data rate information indicating the expected value of the downlink data rate estimated based on the reception state of the wireless communication terminal does not exceed a preset first data rate threshold, Receiving from a radio base station;
When receiving the sub-threshold notification in the receiving step, determining to reduce a communication band allocated to communication performed between the wireless communication terminal and a communication destination device of the wireless communication terminal;
A communication control method comprising: notifying the communication destination device of the communication band determined in the determining step. Receiving from the radio base station a reduction request for reducing a communication band allocated to communication executed between a radio communication terminal and a communication destination device of the radio communication terminal;
Determining to reduce the communication band when receiving the reduction request in the receiving step;
A communication control method comprising: notifying the communication destination device of the communication band determined in the determining step.