JP2008289071A - Radio control apparatus, mobile communication system, and method for controlling band-over between different frequencies - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain a band-over between different frequencies while suppressing reduction in traffic capacity and increase in power consumption. <P>SOLUTION: A different frequency measurement necessity determining means 13a refers to different frequency measurement necessity information 12a to determine whether to cause a mobile station 22 to measure quality of different frequencies and in a case where it is determined that it is necessary to cause the mobile station 22 to measure the quality of different frequencies, a compressed mode setting means 13b determines whether or not a compressed mode is being activated for the mobile station 22. In a case where the compressed mode is not being activated for the mobile station 22, the mobile station 22 and radio base stations 21a-21c are instructed so as to activate the compressed mode. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radio control apparatus, a mobile communication system, and a different frequency band-over control method, and is particularly suitable for application to a method of determining whether or not different frequency measurement is necessary in different frequency band over.

  One of the wireless transmission systems of the IMT-2000 mobile communication system is a W-CDMA (Wideband Code Division Multiple Access) system. In this W-CDMA system, one frequency can be shared by a plurality of users, and the same frequency is repeatedly used in any cell, so there is no need for band-over between different frequencies in the same system.

  However, in reality, multiple frequencies are used in the same system to enable increased traffic capacity and flexible area design, and operate at many frequencies in areas with high traffic capacity such as urban areas. There are cases where the frequency used by each cell is different, such as operating at a low frequency in an area with a low traffic capacity such as a cell. For this reason, in order to move between cells having different operating frequencies without being disconnected, a band-over between different frequencies is required.

In order to realize the band-over between different frequencies, it is necessary to measure the quality of a frequency (hereinafter referred to as a different frequency) different from the frequency being used in the mobile station in order to determine the cell to which the band is over. In the W-CDMA system, a continuous transmission form is usually used, and in order to measure the quality of different frequencies during communication, a plurality of receiving apparatuses are mounted in a mobile station or data transmission / reception is temporarily stopped. In the meantime, it is necessary to measure the quality of different frequencies.
A compressed mode has been proposed as a technique for realizing band-over between different frequencies using a method of measuring the quality of different frequencies while data transmission / reception is stopped (Non-patent Document 1).

In this compressed mode, the radio base station temporarily stops data transmission for a part of the transmission frame, and the quality of the different frequency that is a candidate for the band-over destination is measured by the mobile station. At this time, the radio control apparatus decides to shift to the compressed mode, and notifies the radio base station and the mobile station of information necessary for measuring the quality of different frequencies.
Here, since data transmission is not possible during the measurement of the quality of different frequencies in the compressed mode, the transmission data is compressed before and after the non-transmission interval, and the transmission data is transmitted at a high speed while increasing the transmission power. The transmission speed is maintained.

3rd Generation Partnership Project Technical Technical Group Radio Access Network, 25.211 Physical channel and mapping of transport channel 200

However, if the compressed mode is used frequently in order to realize the band-over between different frequencies, the transmission power increases, causing interference to other users' communication, reducing the traffic capacity of the entire system, There has been a problem of causing an increase in power consumption.
Accordingly, an object of the present invention is to provide a radio control apparatus, a mobile communication system, and an inter-frequency band-over control method capable of realizing inter-frequency band over while suppressing a decrease in traffic capacity and an increase in power consumption. Is to provide.

  In order to solve the above-described problem, according to the radio control device according to claim 1, based on the different frequency measurement necessity information that specifies whether or not the measurement of the quality of the different frequency is in units of cells, A different frequency measurement necessity determination unit that determines whether or not the mobile station performs quality measurement, and the measurement of the different frequency quality to the mobile station based on a determination result by the different frequency measurement necessity determination unit. It is characterized by comprising different frequency measurement instruction means for instructing.

  Further, according to the radio control apparatus according to claim 2, when the different frequency measurement necessity determination means needs to measure the quality of the different frequencies for all the cells that have established communication links with the mobile station. When it is determined that the mobile station needs to measure the quality of the different frequency, and it is not necessary to measure the quality of the different frequency for one or more cells that have established a communication link with the mobile station. And determining that it is not necessary to cause the mobile station to measure the quality of the different frequency.

  According to the radio control apparatus according to claim 3, different frequency measurement necessity information for specifying necessity of measurement of different frequency quality in units of cells, and transmission power value in the radio base station in communication with the mobile station Based on the determination result by the different frequency measurement necessity determination means and the different frequency measurement necessity determination means for determining whether or not to cause the mobile station to measure the quality of the different frequency based on Different frequency measurement instructing means for instructing the mobile station to measure the quality of the mobile station.

  Further, according to the radio control device of claim 4, the different frequency measurement necessity determination means, it is necessary to measure the quality of the different frequency for all cells that have established a communication link with the mobile station, And determining that it is necessary to cause the mobile station to measure the quality of the different frequency when a transmission power value in one or more radio base stations communicating with the mobile station is greater than or equal to a threshold value. If one or more cells that have established a communication link with the mobile station do not need to measure the quality of different frequencies, or the transmission power values at all radio base stations that are communicating with the mobile station are smaller than a threshold, It is determined that it is not necessary to cause the mobile station to perform quality measurement of different frequencies.

  Further, according to the radio control apparatus of claim 5, the different frequency measurement instructing means is required to measure the determination result by the different frequency measurement necessity determining means, and the mobile station has the quality of the different frequency. When the measurement is not in progress, the measurement of the quality of the different frequency is started by the mobile station, the determination result by the different frequency measurement necessity determination unit is not required to be measured, and the mobile station is measuring the quality of the different frequency. In this case, the mobile station stops the measurement of the quality of the different frequency.

  Further, according to the radio control device according to claim 6, when the different frequency measurement instruction means causes the mobile station to start measuring the quality of the different frequency, the radio base station in communication with the mobile station When starting the transmission control for measuring the quality of the different frequency and stopping the measurement of the quality of the different frequency by the mobile station, the quality of the different frequency is measured by the radio base station communicating with the mobile station. Therefore, the transmission control is stopped.

  According to the mobile communication system of claim 7, a radio control apparatus that controls a communication link in a radio section divided into a plurality of cells, a mobile station that communicates with a network while switching the cells, In a mobile communication system comprising a radio base station that establishes a communication link with the mobile station, the radio control device is based on different frequency measurement necessity information that specifies whether or not different frequency quality is measured in units of cells. , Different frequency measurement necessity determination means for determining whether or not to cause the mobile station to measure the quality of the different frequency, and measurement of the quality of the different frequency based on a determination result by the different frequency measurement necessity determination means And a different frequency measurement instruction means for instructing the mobile station.

  According to the mobile communication system of claim 8, a radio network controller that controls a communication link in a radio section divided into a plurality of cells, a mobile station that communicates with a network while switching the cells, In a mobile communication system comprising a radio base station that establishes a communication link with the mobile station, the radio network controller includes different frequency measurement necessity information for specifying whether or not different frequency quality is measured in units of cells, and mobile Different frequency measurement necessity determination means for determining whether or not to cause the mobile station to measure the quality of the different frequency based on a transmission power value in a radio base station in communication with the station, and the different frequency measurement required And a different frequency measurement instruction means for instructing the mobile station to measure the quality of the different frequency based on a determination result by the non-determination means.

  According to the inter-frequency band-over control method according to claim 9, the measurement of the quality of the different frequency is performed based on the different frequency measurement necessity information specifying whether or not the measurement of the quality of the different frequency is in units of cells. In the radio control device, and when it is determined that the mobile station needs to measure the quality of the different frequency, the measurement of the quality of the different frequency is performed. Notifying the mobile station and the radio base station of necessary information, and performing transmission control for measuring the quality of the different frequency at the radio base station, And a step of performing band-over between different frequencies based on a measurement result of the quality of the different frequencies in the mobile station.

  Further, according to the inter-frequency band-over control method according to claim 10, the step of notifying the radio control apparatus of the transmission power value in the radio base station in communication with the mobile station, and the necessity of measuring the quality of the different frequency Whether or not to cause the mobile station to measure the quality of the different frequency based on the different frequency measurement necessity information that specifies the cell unit and the transmission power value in the radio base station in communication with the mobile station. If it is determined in the control device that it is necessary to cause the mobile station to perform the quality measurement of the different frequency, the mobile station and the radio base A step of notifying the mobile station, a step of measuring the quality of the different frequency at the mobile station while performing transmission control for measuring the quality of the different frequency at the radio base station, and the mobile station In Serial based on the measurement result of the quality of different frequencies, characterized in that it comprises the steps of performing different frequency between bands over.

  As described above, according to the present invention, it is possible to cause a mobile station to measure the quality of different frequencies only for cells that are highly required to switch frequencies. For this reason, it is possible to prevent the measurement of the quality of different frequencies from being performed uniformly even for a cell whose necessity of switching the frequency is low, and while suppressing the decrease in traffic capacity and the increase in power consumption, the band between different frequencies can be prevented. Over can be realized.

Hereinafter, a wireless control device according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of a mobile communication system to which a radio control apparatus according to an embodiment of the present invention is applied.
In FIG. 1, the mobile communication system is provided with a radio control device 11 that controls a communication link in a radio section divided into a plurality of cells, and the radio base stations 21 a to 21 c and the core network 6 connect the radio control device 11. Connected through. Then, the wireless section where the communication link is established with the mobile station 22 such as a mobile phone is divided into cells, and the wireless base station 21a is formed with a wireless zone Za1 of the operating frequency f1 and a wireless zone Za2 of the operating frequency f2. The radio base station 21b is formed with a radio zone Zb1 with an operating frequency f1 and a radio zone Zb2 with an operating frequency f2, and the radio base station 21c is formed with a radio zone Zc1 with an operating frequency f1.

And the radio | wireless control apparatus 11 determines the cell in which an appropriate communication link is established from information, such as cell quality, and establishes the communication link between the mobile station 22 and the radio base stations 21a-21c in the cell. Communication between the mobile station 22 and the core network 16 can be realized. In the W-CDMA mobile communication system, the mobile station 22 can simultaneously set up to three communication links depending on the communication status.
Here, the wireless control device 11 includes an information storage unit 12 for storing information for controlling the start and stop of the compressed mode, a control unit 13 for controlling the start and stop of the compressed mode, and the wireless base station. A transmitter / receiver 14 that transmits / receives signals to / from 21a to 21c and a transmitter / receiver 15 that transmits / receives signals to / from the core network 16 are provided.

  In the information storage unit 12, the different frequency measurement necessity information 12a indicating whether or not the measurement of the quality of the different frequency in units of cells and the transmission power value 12b in the radio base stations 21a to 21c communicating with the mobile station 22 are stored. Can be remembered. The different frequency measurement necessity / unnecessity information 12a indicates that different frequency quality measurement is required for cells having a high need for frequency switching, and different frequency quality is not required for cells having a low need for frequency switching. Necessity of measurement of quality can be indicated in cell units.

  The control unit 13 also includes a different frequency measurement necessity determination unit 13a for determining whether or not the mobile station 22 is to measure the quality of the different frequency based on the different frequency measurement necessity information 12a and the different frequency measurement. A compressed mode setting means 13b for setting a compressed mode based on the determination result by the necessity determination means 13a is provided. The different frequency measurement necessity determination means 13a considers the transmission power value 12b together with the different frequency measurement necessity information 12a to determine whether or not the mobile station 22 is to measure the quality of the different frequency. It may be.

  And the radio | wireless control apparatus 11 determines the cell in which an appropriate communication link is established from information, such as cell quality, and establishes the communication link between the mobile station 22 and the radio base stations 21a-21c in the cell. When the communication link between the mobile station 22 and the radio base stations 21 a to 21 c is established, the radio base stations 21 a to 21 c wirelessly transmit the transmission power value 12 b in the radio base stations 21 a to 21 c communicating with the mobile station 22. Notifying the control device 11, the wireless control device 11 can store the transmission power value 12 b in the information storage unit 12.

  Then, the different frequency measurement necessity determination means 13a refers to the different frequency measurement necessity information 12a with the addition, deletion or replacement of the cell being communicated, and causes the mobile station 22 to measure the quality of the different frequency. It is determined whether or not. The different frequency measurement necessity determination means 13a measures the quality of the different frequencies when it is necessary to measure the quality of the different frequencies for all the cells that have established communication links with the mobile station 22. It can be determined that there is a need to implement. Also, the different frequency measurement necessity determination means 13a performs the measurement of the different frequency quality when it is not necessary to measure the different frequency quality for one or more cells that have established a communication link with the mobile station 22. 22 can be determined not to be implemented.

  When it is determined that it is necessary to cause the mobile station 22 to measure the quality of the different frequency, the compressed mode setting unit 13b determines whether the compressed mode is activated for the mobile station 22. . When the compressed mode is not activated for the mobile station 22, the mobile station 22 and the radio base stations 21a to 21c are instructed to activate the compressed mode.

  Then, when the mobile station 22 and the radio base stations 21a to 21c are instructed by the radio control apparatus 11 to activate the compressed mode, the radio base stations 21a to 21c transmit data for a part of the transmission frame. Is temporarily stopped, and the mobile station 22 measures the quality of the different frequency that is a candidate for the band-over destination during that time. When the quality of the different frequency that is a candidate for the band-over destination is good, the radio control apparatus 11 instructs the mobile station 22 to perform the band-over between different frequencies, so that the operation frequencies f1 and f2 are different from each other. It is possible to move between cells without disconnecting communication.

  On the other hand, when the different frequency measurement necessity determination unit 13 a determines that the mobile station 22 does not need to measure the quality of the different frequency, the compressed mode setting unit 13 b uses the compressed mode for the mobile station 22. Determine if is running. When the compressed mode is activated for the mobile station 22, the mobile station 22 and the radio base stations 21a to 21c are instructed to stop the compressed mode.

When the mobile station 22 and the radio base stations 21a to 21c are instructed by the radio control apparatus 11 to stop the compressed mode, the mobile station 22 measures the quality of different frequencies that are candidates for the band-over destination. At the same time, the radio base stations 21a to 21c resume data transmission for the section that has been stopped with the activation of the compressed mode.
The different frequency measurement necessity determination means 13a considers the transmission power value 12b together with the different frequency measurement necessity information 12a to determine whether or not the mobile station 22 is to measure the quality of the different frequency. It may be.

  In this case, the different frequency measurement necessity / unnecessity determination means 13a adds, deletes, or replaces a cell in communication, or notifies the transmission power value 12b from the radio base stations 21a to 21c as a trigger. The transmission power value 12b can be referred to. Then, the different frequency measurement necessity determination means 13a needs to measure the quality of the different frequencies for all the cells that have established communication links with the mobile station 22, and one or more radios that are communicating with the mobile station 22. When the transmission power value 12b in the base stations 21a to 21c is equal to or greater than the threshold value, it can be determined that the mobile station 22 needs to measure the quality of the different frequency. Further, the different frequency measurement necessity determination means 13a does not need to measure the quality of the different frequency for one or more cells that have established a communication link with the mobile station 22, or all the communication with the mobile station 22 is in progress. When the transmission power value 12b in the radio base stations 21a to 21c is smaller than the threshold value, it can be determined that it is not necessary to cause the mobile station 22 to measure the quality of the different frequency.

  As a result, it is possible to cause the mobile station 22 to measure the quality of different frequencies only for cells that are highly required to switch frequencies. For this reason, it is possible to prevent the measurement of the quality of different frequencies from being performed uniformly even for a cell whose necessity of switching the frequency is low, and while suppressing the decrease in traffic capacity and the increase in power consumption, the band between different frequencies can be prevented. Over can be realized.

FIG. 2 is a block diagram illustrating a method for controlling inter-frequency bandover according to an embodiment of the present invention.
In FIG. 2, the radio zone Za1 of the operating frequency f1 is divided into cells C1a to C1n, the radio zone Za2 of the operating frequency f2 is divided into cells C2a to C2n, and the radio zone Zb1 of the operating frequency f1 is divided into cells C3a to C3n. The radio zone Zb2 with the operating frequency f2 is divided into cells C4a to C4n, and the radio zone Zc1 with the operating frequency f1 is divided into cells C5a to C5n.

The different frequency measurement necessity information 12a includes the measurement necessity of the different frequency quality for the cells C4a to C4n and the measurement of the different frequency quality for the cells C1a to C1n, C2a to C2n, C3a to C3n, and C5a to C5n. It shall be described as unnecessary.
Then, it is assumed that the mobile station 22 moves in the direction of the radio zone Zc1 while establishing a communication link in the cell C2b in the radio zone Za2 of the operating frequency f2. When the mobile station 22 approaches the wireless zone Zb2 (P1), the mobile station 22 newly establishes a communication link in the cell C4a while establishing a communication link in the cell C2b. Then, when a communication link is newly established in the cell C4a, the different frequency measurement necessity determination means 13a refers to the different frequency measurement necessity information 12a, and all the cells that have established communication links with the mobile station 22 It is determined whether it is necessary to measure the quality of the different frequency f1 for C2b and C4a.

  Here, the different frequency measurement necessity information 12a describes that it is not necessary to measure the quality of the different frequency f1 for the cell C2b that has established a communication link with the mobile station 22. The condition that it is necessary to measure the quality of the different frequency f1 for all the cells C2b and C4a that have established communication links is not satisfied. For this reason, the different frequency measurement necessity determination means 13a determines that there is no need to cause the mobile station 22 to measure the quality of the different frequency f1 and prevents the compressed mode from being activated.

  Further, when the mobile station 22 moves in the direction of the wireless zone Zc1 while establishing communication links in the cells C2b and C4a (P2), the mobile station 22 deletes the communication link in the cell C2b. Then, when the communication link in the cell C2b is deleted, the different frequency measurement necessity determination unit 13a refers to the different frequency measurement necessity information 12a for all the cells C4a that have established communication links with the mobile station 22. It is determined whether it is necessary to measure the quality of the different frequency f1.

  Here, the different frequency measurement necessity information 12a describes that it is necessary to measure the quality of the different frequency f1 for the cell C4a that establishes a communication link with the mobile station 22, and the mobile station 22 receives the cell C4a. Since only the communication link is established, the condition that the measurement of the quality of the different frequency f1 is necessary for all the cells C4a having established the communication link with the mobile station 22 is satisfied. For this reason, the different frequency measurement necessity determination means 13a determines that the mobile station 22 needs to measure the quality of the different frequency f1. When it is determined that the mobile station 22 needs to measure the quality of the different frequency f1, the compressed mode setting unit 13b determines whether the compressed mode is being activated for the mobile station 22. If the compressed mode is not activated for the mobile station 22, the mobile station 22 and the radio base station 21b are instructed to activate the compressed mode.

Then, when the mobile station 22 and the radio base station 21b are instructed by the radio control device 11 to activate the compressed mode, the radio base station 21b temporarily transmits data for a partial section of the transmission frame. In the meantime, the mobile station 22 measures the quality of the different frequency f1 that is a candidate for the band-over destination. When the quality of the different frequency f1 that is a candidate for the band-over destination is good, the radio control apparatus 11 instructs the mobile station 22 to implement the band-over between different frequencies, and in the radio zone Zb1 of the operating frequency f1, A communication link is newly established in the cell C3b (P3).
When a communication link is newly established in the cell C3b, the different frequency measurement necessity determination means 13a refers to the different frequency measurement necessity information 12a, and all the cells that have established communication links with the mobile station 22 It is determined whether it is necessary to measure the quality of the different frequency f2 for C3b.

  Here, in the different frequency measurement necessity information 12a, it is described that the measurement of the quality of the different frequency f2 is not necessary for the cell C3b that has established the communication link with the mobile station 22, so the mobile station 22 And the condition that it is necessary to measure the quality of the different frequency f2 for all the cells C3b that have established communication links. For this reason, the different frequency measurement necessity determination means 13a determines that it is not necessary to cause the mobile station 22 to measure the quality of the different frequency f2. Then, when it is determined that the mobile station 22 does not need to measure the quality of the different frequencies, the compressed mode setting unit 13b determines whether the compressed mode is being activated for the mobile station 22. When the compressed mode is being activated for the mobile station 22, the mobile station 22 and the radio base station 21b are instructed to stop the compressed mode.

When the mobile station 22 and the radio base station 21b are instructed by the radio control apparatus 11 to stop the compressed mode, the mobile station 22 stops measuring the quality of the different frequency f2 that is a candidate for the band-over destination. At the same time, the radio base station 21b resumes data transmission for the section that has been stopped with the activation of the compressed mode.
When the mobile station 22 moves in the direction of the wireless zone Zc1 while establishing a communication link in the cell C3b (P4), the mobile station 22 newly establishes a communication link in the cell C5a while maintaining the communication link in the cell C3b. Then, when a communication link is newly established in the cell C5a, the different frequency measurement necessity determination means 13a refers to the different frequency measurement necessity information 12a, and all the cells that have established communication links with the mobile station 22 It is determined whether it is necessary to measure the quality of the different frequency f2 for C3b and C5a.

  Here, in the different frequency measurement necessity information 12a, it is described that the measurement of the quality of the different frequency f2 is not necessary for the cell C5a that has established a communication link with the mobile station 22, so the mobile station 22 And the condition that it is necessary to measure the quality of the different frequency f2 for all the cells C3b and C5a that have established communication links. For this reason, the different frequency measurement necessity determination means 13a determines that there is no need to cause the mobile station 22 to measure the quality of the different frequency f2 and prevents the compressed mode from being activated.

  Further, when the mobile station 22 moves in the direction of the wireless zone Zc1 while establishing communication links in the cells C3b and C5a (P5), the mobile station 22 deletes the communication link in the cell C3b. When the communication link in the cell C3b is deleted, the different frequency measurement necessity determination unit 13a refers to the different frequency measurement necessity information 12a, and all the cells C5a that have established communication links with the mobile station 22 are referred to. It is determined whether it is necessary to measure the quality of the different frequency f2.

  Here, in the different frequency measurement necessity information 12a, it is described that the measurement of the quality of the different frequency f2 is not necessary for the cell C5a that has established a communication link with the mobile station 22, so the mobile station 22 And the condition that it is necessary to measure the quality of the different frequency f2 for all the cells C5a that have established communication links. For this reason, the different frequency measurement necessity determination means 13a determines that there is no need to cause the mobile station 22 to measure the quality of the different frequency f2 and prevents the compressed mode from being activated.

Alternatively, the different frequency measurement necessity determination means 13a determines whether or not the mobile station 22 is to measure the quality of the different frequency by considering the transmission power value 12b together with the different frequency measurement necessity information 12a. You can also.
In this case, it is assumed that the mobile station 22 is moving in the direction of the wireless zone Zc1 while establishing a communication link in the cell C2b in the wireless zone Za2 of the operating frequency f2. When the mobile station 22 approaches the wireless zone Zb2 (P1), the mobile station 22 newly establishes a communication link in the cell C4a while establishing a communication link in the cell C2b. Then, when a communication link is newly established in the cell C4a, the different frequency measurement necessity determination means 13a refers to the different frequency measurement necessity information 12a, and all the cells that have established communication links with the mobile station 22 It is determined whether it is necessary to measure the quality of the different frequency f1 for C2b and C4a.

  Here, the different frequency measurement necessity information 12a describes that it is not necessary to measure the quality of the different frequency f1 for the cell C2b that has established a communication link with the mobile station 22. The condition that it is necessary to measure the quality of the different frequency f1 for all the cells C2b and C4a that have established communication links is not satisfied. For this reason, the different frequency measurement necessity determination means 13a determines that there is no need to cause the mobile station 22 to measure the quality of the different frequency f1 and prevents the compressed mode from being activated.

  Further, when the mobile station 22 moves in the direction of the wireless zone Zc1 while establishing communication links in the cells C2b and C4a (P2), the mobile station 22 deletes the communication link in the cell C2b. Then, when the communication link in the cell C2b is deleted, the different frequency measurement necessity determination unit 13a refers to the different frequency measurement necessity information 12a for all the cells C4a that have established communication links with the mobile station 22. It is determined whether it is necessary to measure the quality of the different frequency f1.

Here, the different frequency measurement necessity information 12a describes that it is necessary to measure the quality of the different frequency f1 for the cell C4a that establishes a communication link with the mobile station 22, and the mobile station 22 receives the cell C4a. Since only the communication link is established, the condition that the measurement of the quality of the different frequency f1 is necessary for all the cells C4a having established the communication link with the mobile station 22 is satisfied.
When it is necessary to measure the quality of the different frequency f1 for all the cells C4a that have established communication links with the mobile station 22, the transmission power value 12b in the radio base station 21b communicating with the mobile station 22 is equal to or greater than the threshold value. It is determined whether or not.

When the mobile station 22 is away from the radio base station 21b, the transmission power value 12b at the radio base station 21b communicating with the mobile station 22 is increased, so that the transmission power value 12b is equal to or greater than the threshold value. For this reason, the different frequency measurement necessity determination means 13a determines that the mobile station 22 needs to measure the quality of the different frequency f1.
When it is determined that the mobile station 22 needs to measure the quality of the different frequency f1, the compressed mode setting unit 13b determines whether the compressed mode is being activated for the mobile station 22. If the compressed mode is not activated for the mobile station 22, the mobile station 22 and the radio base station 21b are instructed to activate the compressed mode.

  Then, when the mobile station 22 and the radio base station 21b are instructed by the radio control device 11 to activate the compressed mode, the radio base station 21b temporarily transmits data for a partial section of the transmission frame. In the meantime, the mobile station 22 measures the quality of the different frequency f1 that is a candidate for the band-over destination. Then, when the mobile station 22 further moves in the direction of the radio zone Zc1 without performing inter-frequency bandover and approaches the radio base station 21b, the transmission power value in the radio base station 21b communicating with the mobile station 22 Since 12b becomes smaller, the transmission power value 12b becomes smaller than the threshold value. For this reason, the different frequency measurement necessity determination means 13a determines that it is not necessary to cause the mobile station 22 to measure the quality of the different frequency f1.

  Then, when it is determined that the mobile station 22 does not need to measure the quality of the different frequencies, the compressed mode setting unit 13b determines whether the compressed mode is being activated for the mobile station 22. When the compressed mode is being activated for the mobile station 22, the mobile station 22 and the radio base station 21b are instructed to stop the compressed mode.

When the mobile station 22 and the radio base station 21b are instructed by the radio control apparatus 11 to stop the compressed mode, the mobile station 22 stops measuring the quality of the different frequency f2 that is a candidate for the band-over destination. At the same time, the radio base station 21b resumes data transmission for the section that has been stopped with the activation of the compressed mode.
Then, the mobile station 22 further moves in the direction of the radio zone Zc1 while establishing a communication link in the cell C4a. When the mobile station 22 moves away from the radio base station 21b, the mobile station 22 communicates with the mobile station 22 at the radio base station 21b. Since the transmission power value 12b is increased, the transmission power value 12b is equal to or greater than the threshold value. For this reason, the different frequency measurement necessity determination means 13a determines that the mobile station 22 needs to measure the quality of the different frequency f1.

  When it is determined that the mobile station 22 needs to measure the quality of the different frequency f1, the compressed mode setting unit 13b determines whether the compressed mode is being activated for the mobile station 22. If the compressed mode is not activated for the mobile station 22, the mobile station 22 and the radio base station 21b are instructed to activate the compressed mode.

  Then, when the mobile station 22 and the radio base station 21b are instructed by the radio control device 11 to activate the compressed mode, the radio base station 21b temporarily transmits data for a partial section of the transmission frame. In the meantime, the mobile station 22 measures the quality of the different frequency f1 that is a candidate for the band-over destination. When the quality of the different frequency f1 that is a candidate for the band-over destination is good, the radio control apparatus 11 instructs the mobile station 22 to implement the band-over between different frequencies, and in the radio zone Zb1 of the operating frequency f1, A communication link is newly established in the cell C3b (P3).

When a communication link is newly established in the cell C3b, the different frequency measurement necessity determination means 13a refers to the different frequency measurement necessity information 12a, and all the cells that have established communication links with the mobile station 22 It is determined whether it is necessary to measure the quality of the different frequency f2 for C3b.
Here, in the different frequency measurement necessity information 12a, it is described that the measurement of the quality of the different frequency f2 is not necessary for the cell C3b that has established the communication link with the mobile station 22, so the mobile station 22 And the condition that it is necessary to measure the quality of the different frequency f2 for all the cells C3b that have established communication links. For this reason, the different frequency measurement necessity determination means 13a determines that it is not necessary to cause the mobile station 22 to measure the quality of the different frequency f2. Then, when it is determined that the mobile station 22 does not need to measure the quality of the different frequencies, the compressed mode setting unit 13b determines whether the compressed mode is being activated for the mobile station 22. When the compressed mode is being activated for the mobile station 22, the mobile station 22 and the radio base station 21b are instructed to stop the compressed mode.

When the mobile station 22 and the radio base station 21b are instructed by the radio control apparatus 11 to stop the compressed mode, the mobile station 22 stops measuring the quality of the different frequency f2 that is a candidate for the band-over destination. At the same time, the radio base station 21b resumes data transmission for the section that has been stopped with the activation of the compressed mode.
When the mobile station 22 moves in the direction of the wireless zone Zc1 while establishing a communication link in the cell C3b (P4), the mobile station 22 newly establishes a communication link in the cell C5a while maintaining the communication link in the cell C3b. Then, when a communication link is newly established in the cell C5a, the different frequency measurement necessity determination means 13a refers to the different frequency measurement necessity information 12a, and all the cells that have established communication links with the mobile station 22 It is determined whether it is necessary to measure the quality of the different frequency f2 for C3b and C5a.

  Here, in the different frequency measurement necessity information 12a, it is described that the measurement of the quality of the different frequency f2 is not necessary for the cell C5a that has established a communication link with the mobile station 22, so the mobile station 22 And the condition that it is necessary to measure the quality of the different frequency f2 for all the cells C3b and C5a that have established communication links. For this reason, the different frequency measurement necessity determination means 13a determines that there is no need to cause the mobile station 22 to measure the quality of the different frequency f2 and prevents the compressed mode from being activated.

  Further, when the mobile station 22 moves in the direction of the wireless zone Zc1 while establishing communication links in the cells C3b and C5a (P5), the mobile station 22 deletes the communication link in the cell C3b. When the communication link in the cell C3b is deleted, the different frequency measurement necessity determination unit 13a refers to the different frequency measurement necessity information 12a, and all the cells C5a that have established communication links with the mobile station 22 are referred to. It is determined whether it is necessary to measure the quality of the different frequency f2.

  Here, in the different frequency measurement necessity information 12a, it is described that the measurement of the quality of the different frequency f2 is not necessary for the cell C5a that has established a communication link with the mobile station 22, so the mobile station 22 And the condition that it is necessary to measure the quality of the different frequency f2 for all the cells C5a that have established communication links. For this reason, the different frequency measurement necessity determination means 13a determines that there is no need to cause the mobile station 22 to measure the quality of the different frequency f2 and prevents the compressed mode from being activated.

FIG. 3 is a flowchart illustrating a compressed mode setting method according to an embodiment of the present invention.
In FIG. 3, the different frequency measurement necessity determination means 13 a refers to the different frequency measurement necessity information 12 a in response to the addition, deletion or replacement of a cell in communication, and measures the quality of the different frequency to the mobile station 22. It is determined whether or not to implement (step S11).
When it is determined that it is necessary to cause the mobile station 22 to measure the quality of the different frequency, the compressed mode setting unit 13b determines whether the compressed mode is activated for the mobile station 22. (Step S12). If the compressed mode is not activated for the mobile station 22, the mobile station 22 and the radio base stations 21a to 21c are instructed to activate the compressed mode (step S13).

  On the other hand, when the different frequency measurement necessity determination unit 13 a determines that the mobile station 22 does not need to measure the quality of the different frequency, the compressed mode setting unit 13 b uses the compressed mode for the mobile station 22. Is determined to be active (step S14). When the compressed mode is being activated for the mobile station 22, the mobile station 22 and the radio base stations 21a to 21c are instructed to stop the compressed mode (step S15).

FIG. 4 is a flowchart showing a method for determining the necessity of different frequency measurement according to an embodiment of the present invention.
In FIG. 4, the different frequency measurement necessity determination means 13a determines whether or not the measurement of the quality of the different frequency is necessary for all the cells that have established communication links with the mobile station 22 (step S21). Then, if it is necessary to measure the quality of different frequencies for all the cells that have established communication links with the mobile station 22, it is determined that the mobile station 22 needs to measure the quality of different frequencies (steps). S22).
On the other hand, the different frequency measurement necessity determination unit 13a measures the quality of the different frequency when the measurement of the quality of the different frequency is unnecessary for one or more cells that have established a communication link with the mobile station 22. (Step S23).

FIG. 5 is a flowchart showing another example of a method for determining the necessity of different frequency measurement according to an embodiment of the present invention.
In FIG. 5, the different frequency measurement necessity determination means 13a determines whether it is necessary to measure the quality of the different frequencies for all the cells that have established communication links with the mobile station 22 (step S31). When it is necessary to measure the quality of different frequencies for all the cells that have established communication links with the mobile station 22, the transmission power value 12b in one or more radio base stations 21a to 21c communicating with the mobile station 22 is required. Is determined to be greater than or equal to a threshold value (step S32). When the transmission power value 12b in one or more radio base stations 21a to 21c communicating with the mobile station 22 is equal to or greater than the threshold value, it is determined that the mobile station 22 needs to measure the quality of the different frequency ( Step S33).

  On the other hand, the different frequency measurement necessity determination unit 13a does not need to measure the quality of the different frequency for one or more cells that have established a communication link with the mobile station 22, or all communication with the mobile station 22 is in progress. When the transmission power value 12b in the radio base stations 21a to 21c is smaller than the threshold value, it is determined that it is not necessary to cause the mobile station 22 to measure the quality of the different frequency (step S34).

It is a block diagram which shows schematic structure of the mobile communication system with which the radio | wireless control apparatus which concerns on one Embodiment of this invention is applied. It is a block diagram which shows the control method of the different frequency bandover which concerns on one Embodiment of this invention. It is a flowchart which shows the setting method of the compressed mode which concerns on one Embodiment of this invention. It is a flowchart which shows the determination method of the necessity of different frequency measurement which concerns on one Embodiment of this invention. It is a flowchart which shows the other example of the determination method of the necessity of different frequency measurement which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Radio control apparatus 12 Information storage part 12a Different frequency measurement necessity information 12b Transmission power value 13 Control part 13a Different frequency measurement necessity judgment means 13b Compressed mode setting means 14, 15 Transmission / reception parts 21a-21c Radio base station 22 Mobile station Za1, Za2, Zb1, Zb2, Zc1 Wireless zone

Claims (10)

Different frequency measurement necessity determination that determines whether or not the mobile station is to perform the measurement of the different frequency quality based on the different frequency measurement necessity information that specifies whether or not the different frequency quality is measured in cell units. Means,
A radio control apparatus comprising: different frequency measurement instruction means for instructing the mobile station to measure the quality of the different frequency based on a determination result by the different frequency measurement necessity determination means. The different frequency measurement necessity determination means includes:
If it is necessary to measure the quality of different frequencies for all cells that have established a communication link with the mobile station, determine that the mobile station needs to measure the quality of the different frequencies,
Determining that it is not necessary for the mobile station to measure the quality of the different frequency when it is not necessary to measure the quality of the different frequency for one or more cells that have established a communication link with the mobile station. The wireless control device according to claim 1. The measurement of the quality of the different frequency is performed on the basis of the different frequency measurement necessity information for specifying the necessity of measurement of the quality of the different frequency in cell units and the transmission power value in the radio base station in communication with the mobile station. Different frequency measurement necessity judging means for judging whether or not to make the station implement,
A radio control apparatus comprising: different frequency measurement instruction means for instructing the mobile station to measure the quality of the different frequency based on a determination result by the different frequency measurement necessity determination means. The different frequency measurement necessity determination means includes:
When it is necessary to measure the quality of different frequencies for all cells that have established communication links with the mobile station, and the transmission power value at one or more radio base stations in communication with the mobile station is greater than or equal to a threshold value And determining that the mobile station needs to measure the quality of the different frequency,
When it is not necessary to measure the quality of different frequencies for one or more cells that have established a communication link with the mobile station, or the transmission power values of all radio base stations that are communicating with the mobile station are smaller than a threshold value The radio control apparatus according to claim 3, further comprising: determining that the mobile station does not need to measure the quality of the different frequency. The different frequency measurement instruction means includes
If the determination result by the different frequency measurement necessity determination means is measurement required and the mobile station is not measuring the quality of the different frequency, the mobile station starts measuring the quality of the different frequency,
When the determination result by the different frequency measurement necessity determining means is not required to be measured and the mobile station is measuring the quality of the different frequency, the mobile station stops measuring the quality of the different frequency. The radio control apparatus according to claim 1, wherein the radio control apparatus is characterized. The different frequency measurement instruction means includes
When starting the measurement of the quality of the different frequency to the mobile station, to start the transmission control to measure the quality of the different frequency to the radio base station in communication with the mobile station,
The transmission control for measuring the quality of the different frequency is stopped in a radio base station communicating with the mobile station when the measurement of the quality of the different frequency is stopped by the mobile station. 6. The wireless control device according to any one of items 1 to 5. A radio network controller for controlling a communication link in a radio section divided into a plurality of cells;
A mobile station communicating with the network while switching the cell;
In a mobile communication system comprising a radio base station that establishes a communication link with the mobile station in the cell,
The wireless control device
Different frequency measurement necessity determination that determines whether or not the mobile station is to perform the measurement of the different frequency quality based on the different frequency measurement necessity information that specifies whether or not the different frequency quality is measured in cell units. Means,
A mobile communication system comprising: different frequency measurement instruction means for instructing the mobile station to measure the quality of the different frequency based on a determination result by the different frequency measurement necessity determination means. A radio network controller for controlling a communication link in a radio section divided into a plurality of cells;
A mobile station communicating with the network while switching the cell;
In a mobile communication system comprising a radio base station that establishes a communication link with the mobile station in the cell,
The wireless control device
The measurement of the quality of the different frequency is performed on the basis of the different frequency measurement necessity information for specifying the necessity of measurement of the quality of the different frequency in cell units and the transmission power value in the radio base station in communication with the mobile station. Different frequency measurement necessity judging means for judging whether or not to make the station implement,
A mobile communication system comprising: different frequency measurement instruction means for instructing the mobile station to measure the quality of the different frequency based on a determination result by the different frequency measurement necessity determination means. A step of determining by a radio control apparatus whether or not to cause the mobile station to perform the measurement of the quality of the different frequency based on the different frequency measurement necessity information specifying whether or not the measurement of the quality of the different frequency is a cell unit. When,
When it is determined that it is necessary to cause the mobile station to measure the quality of the different frequency, notifying the mobile station and the radio base station of information necessary for measuring the quality of the different frequency;
While performing transmission control for measuring the quality of the different frequency in the radio base station, measuring the quality of the different frequency in the mobile station,
And a step of performing band-over between different frequencies based on a measurement result of the quality of the different frequencies in the mobile station. Notifying the radio network controller of the transmission power value in the radio base station in communication with the mobile station;
The measurement of the quality of the different frequency is moved based on different frequency measurement necessity information for specifying the necessity of measurement of the quality of the different frequency in cell units and the transmission power value in the radio base station in communication with the mobile station. A step of determining by the wireless control device whether or not to cause the station to perform,
When it is determined that it is necessary to cause the mobile station to measure the quality of the different frequency, notifying the mobile station and the radio base station of information necessary for measuring the quality of the different frequency;
While performing transmission control for measuring the quality of the different frequency in the radio base station, measuring the quality of the different frequency in the mobile station,
And a step of performing band-over between different frequencies based on a measurement result of the quality of the different frequencies in the mobile station.

Images