KR101235648B1 - Apparatus and Method for Controlling Parameters in Mobile Communication System - Google Patents

Abstract

A parameter control apparatus and method for dynamically changing a parameter used for handoff in a mobile communication system are provided.

The parameter control device of the present invention is connected to a base station controller of a mobile communication system providing a voice call service or a packet data service to a mobile communication terminal, and handoffs according to the number of measurement reports transmitted from each mobile communication terminal for a specified time. When the parameter is updated and the preset handoff parameter update time arrives, the updated handoff parameter is transmitted to the base station controller.

According to the present invention, by changing the handoff parameter dynamically according to the radio environment of the cell, it is possible to prevent frequent handoff, thereby improving the quality of service.

Handoff, parameter

Description

Apparatus and Method for Controlling Parameters in Mobile Communication System}

1 is an exemplary diagram of a communication system to which a parameter control apparatus according to the present invention is applied;

2 is a detailed configuration diagram of the parameter control device shown in FIG. 1;

3 is a detailed configuration diagram of a parameter determination unit shown in FIG. 2;

4 is a flowchart illustrating a parameter control method according to an embodiment of the present invention;

5 is a detailed flowchart of the parameter extraction process shown in FIG. 4.

Description of the Related Art [0002]

10: parameter control device 110: control unit

120: parameter determination unit 130: memory

140: timer 150: parameter change unit

1210: measurement report collection module 1220: count module

1230: specific gravity check module 1240: parameter extraction module

The present invention relates to a parameter control apparatus and method for a communication system, and more particularly, to a parameter control apparatus and method for dynamically changing a parameter used for handoff in a mobile communication system.

In general, when a mobile communication terminal moves to a cell-to-cell boundary area, handoff (or handover) is performed. Handoff can be classified into soft handoff and hard handoff. In the case of soft handoff, resource consumption is increased because a link must be established in both the source and target cells. In addition, in the case of hard handoff, there is a problem that the signal on the source side is weakened until the handoff is completed, thereby reducing the signal transmission rate.

For handoff, the mobile communication terminal periodically measures transmission and reception signals with neighboring base stations, and reports a measurement report to the mobile communication system when the handoff condition is satisfied. The mobile communication system performs the handoff procedure with reference to the measurement report.

The measurement report is transmitted to the mobile communication system when the signal strength received by the mobile communication terminal from the base station is less than or equal to a predetermined level and is maintained for a predetermined time. Here, the specified signal strength level is referred to as hysteresis (H), The preset time is called a time to trigger (TTT). Therefore, the smaller the handoff parameter such as the hysteresis setting value and the trigger time setting value, the more frequently the mobile communication terminal transmits the measurement report to the mobile communication system, and consequently the handoff frequency also increases.

In addition, when the mobile communication terminal is located at the boundary area of the cell instead of moving to the coverage of a completely different cell through the boundary area of the cell, the handoff is repeatedly performed as the power intensity changes frequently in the boundary area between cells. Phosphorus, a so-called ping-pong phenomenon, is generated. Accordingly, the terminal located in the cell boundary region increases the frequency of sending a measurement report to the mobile communication system as compared to the terminal that is not, thereby wasting radio resources and degrading service quality.

That is, in the current mobile communication system, since the parameters for handoff, for example, the hysteresis setting value and the trigger time setting value are fixed, regardless of the number of terminals accommodated in the cell or the type of service provided, the same is always the same. Since the handoff is performed under the condition, there is a need for a method for adaptive handoff according to the cell environment.

In particular, a terminal located in a boundary area between cells and using a packet data service frequently transmits a measurement report, resulting in a decrease in data transmission rate, resulting in a decrease in throughput of the entire cell. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a technical problem to provide a parameter control apparatus and method for a mobile communication system that can adaptively change a handoff parameter according to a wireless environment of a cell. .

Another technical problem of the present invention is to increase cell capacity by dynamically changing a handoff parameter.

The parameter control apparatus according to an embodiment of the present invention for achieving the above-described technical problem is connected to the base station controller of the mobile communication system providing a voice call service or a packet data service to the mobile communication terminal, each movement for a specified time The handoff parameter is updated according to the number of measurement reports transmitted from the communication terminal, and when the preset handoff parameter update time arrives, the updated handoff parameter is transmitted to the base station controller.

In addition, the parameter control method according to an embodiment of the present invention is a handoff parameter control method of a mobile communication terminal connected to a mobile communication system using a voice or packet data service, the measurement being transmitted from each mobile communication terminal for a specified time A first step of extracting and storing handoff parameters according to the number of reports; A second step of confirming whether a handoff parameter update period has arrived; A third step of requesting to change the handoff parameter by transmitting the handoff parameter extracted in the first step to the mobile communication system when a parameter update period arrives as a result of the checking of the second step; And a fourth process of resetting the timer and returning to the first process.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a communication system to which a parameter control apparatus according to the present invention is applied.

As shown, the parameter control apparatus 10 according to the present invention is connected to the base station controller 320 to update the handoff parameter according to a given condition, and when a preset handoff parameter update time arrives, the system information block By including the updated handoff parameter in the transmission to the mobile communication terminal through the base station controller 320 and the base station (310-1 ~ 310-n), the handoff condition is changed according to the radio environment of the cell. Here, the parameter control apparatus 10 receives the measurement report received from the mobile station by the base stations 310-1 to 310-n from the base station controller 320, and receives from the at least one mobile communication terminal for a specified time. When the number of received measurement reports is greater than or equal to a preset allowable value, a mobile communication terminal that transmits a measurement report of more than the allowable value among all mobile communication terminals using a service in a specific cell (hereinafter, referred to as a 'ping-pong terminal'). This specific gravity is calculated, and the handoff parameter is updated when the calculated value is equal to or larger than the preset value. In determining the handoff parameter, in order to prevent the mobile communication terminal frequently transmitting a measurement report to increase the handoff frequency, a predefined handoff parameter such as hysteresis (H) and trigger time (TTT) is increased. It is preferable to update in the direction to make. In addition, when calculating the specific gravity, it is preferable to use only the number of ping-pong terminals using the packet data service among the ping-pong terminals.

Meanwhile, the mobile communication terminal 10 is connected to the circuit network 330 or the data network 340 through the base stations 310-1 to 310-n and the base station controller 320 to use a voice call service or a packet data service. And, it measures the signal strength of the transmission and reception with the neighboring base station at a specified period. The controller 10 receives the handoff parameter dynamically determined by the parameter control apparatus 10 through the base station controller 320 and the base stations 310-1 ˜ 310-n, and transmits a measurement report to the base station when the handoff is required.

FIG. 2 is a detailed configuration diagram of the parameter control device shown in FIG. 1.

As shown, the parameter control apparatus 10 includes a control unit 110 for controlling the overall operation, a parameter determination unit 120 for updating a handoff parameter according to a given condition, a predefined handoff parameter and a parameter determination unit In operation 120, the memory 130 stores the updated parameters, checks whether the handoff parameter update time has arrived, and when the timer 140 and the handoff parameter update time arrive, which are reset after the handoff parameter update, arrive at the memory ( And a parameter change unit 150 which transmits the parameter stored in the 130 to the base station controller 320 and requests the parameter change.

More specifically, the parameter determiner 120 receives a measurement report for each mobile communication terminal from the base station controller 320 for a preset time and counts the number of received measurement reports. When there is at least one ping pong terminal, a specific gravity of the ping pong terminal among all mobile communication terminals using a service in a specific cell is calculated, and the handoff parameter is changed when the calculated value is greater than or equal to a preset value. In this case, it is preferable to change the updated handoff parameter to have a larger value than the predefined handoff parameter, and when calculating the specific gravity, it is preferable to use the number of ping-pong terminals using the packet data service.

If the ping pong terminal is not detected for a preset time or if the ping pong terminal is detected but the proportion of the ping pong terminal for all the terminals using the service in a specific cell is smaller than the preset value, the predefined handoff parameter is updated. Select by value.

The parameter updated by the parameter determiner 120 is temporarily stored in the memory 130. When the handoff update time is confirmed through the timer 140, the parameter change unit 150 is stored in the memory 130. The update parameter is transmitted to the base station controller 320 to request the parameter update.

FIG. 3 is a detailed configuration diagram of the parameter determination unit shown in FIG. 2.

In order to dynamically change the handoff parameter according to the radio environment of the cell, the present invention uses the number of measurement reports transmitted by the mobile communication terminal for a preset time. That is, the measurement report collection module 1210 receives the measurement report transmitted for each mobile communication terminal from the base station controller 320 and increments the count by the count module 1220 each time the measurement report is received.

The specific gravity checking module 1230 calculates the proportion of the ping-pong terminal to all mobile communication terminals that are using the service in a specific cell when there is a mobile communication terminal, that is, a ping-pong terminal that transmits a measurement report of a predetermined value or more for a predetermined time. do.

The parameter extraction module 1240 determines the handoff parameter according to the result of the confirmation of the specific gravity checking module 1230. If the ping pong terminal is not detected for a preset time or the ping pong terminal is detected for the preset time, When the specific gravity of all the mobile communication terminals in the cell is smaller than the preset value, the handoff parameter previously defined in the memory 130 is determined as the update parameter. On the other hand, if the ping-pong terminal is detected for a preset time, and if the proportion of the ping-pong terminal to all the mobile communication terminals using the service in a specific cell is greater than or equal to the preset value, the predefined handoff parameter is updated. In this case, it is preferable to update the handoff parameter in a direction of increasing handoff parameters such as a predefined hysteresis and a trigger time so that the mobile communication terminal does not perform frequent handoff.

4 is a flowchart illustrating a parameter control method according to an embodiment of the present invention.

In order to control the handoff parameter, the parameter determiner 120 repeats the process of extracting the handoff parameter in the memory 130 according to a given condition (S10), and the controller 110 via the timer 140. It is checked whether the parameter update period has arrived (S20).

As a result of the check, when the parameter update cycle arrives, the controller 110 transmits a parameter stored in the memory 130 to the base station controller to request a change of the handoff parameter (S40), and the next parameter update cycle arrives. Timer 140 is reset to wait until.

On the other hand, when the parameter update period has not arrived as a result of checking in step S20, the controller 110 deletes the parameter stored in the memory 130 (S50), and returns to step S10.

5 is a detailed flowchart of the parameter extraction process shown in FIG. 4.

To determine the parameter, the parameter determiner 120 collects a measurement report for each mobile communication terminal for a preset time after performing the initialization step S101 and checks whether a ping-pong terminal exists (S103 to S109).

That is, the measurement report collection module 1210 collects the measurement report for each mobile communication terminal from the base station controller (S103), and increases the count by the count module 1220 each time the measurement report is collected (S105). Then, it is checked whether the preset time has elapsed (S107). If the set time has not elapsed, the process proceeds to step S103. If the set time has elapsed, the specific gravity check module 1230 transmits the measurement report more than the allowable value. It is checked whether one mobile communication terminal exists (S109).

As a result of checking in step S109, if the ping-pong terminal does not exist, the parameter extraction module 1240 extracts a handoff parameter predefined in the memory as an updated handoff parameter.

If, as a result of checking in step S109, if a ping pong terminal exists, the specific gravity checking module 1230 calculates the specific gravity of the ping pong terminal for all the terminals using the service in a specific cell (S113), the calculated value and the set value Is compared (S115).

As a result of the comparison, when the calculated value is smaller than the preset value, that is, when the number of ping-pong terminals is not large, the process proceeds to step S111, and when the calculated value is more than the preset value, the parameter is changed (S117). When changing the parameter in step S117, it is preferable to change the handoff parameter to have a larger value than the predefined parameter. In addition, when calculating the specific gravity in step S113, it is preferable to use the number of terminals using the packet data service among the ping-pong terminals.

On the other hand, the present invention can be implemented in the form of a recording medium to be executed in the base station controller.

That is, a first function of extracting and storing handoff parameters according to the number of measurement reports transmitted from each mobile communication terminal for a specified time, a second function of checking whether a handoff parameter update period arrives, and a parameter update period arrive In one case, a program for transmitting the extracted handoff parameter to the mobile communication system to sequentially execute the function of requesting to change the handoff parameter and the function of resetting the timer and repeating the first function again.

Here, the first function is to collect a measurement report for each mobile communication terminal for a preset time, and whether there is a mobile communication terminal (hereinafter referred to as 'ping pong terminal') that transmits a measurement report more than a predetermined allowable value for a preset time. A function for checking, a function of extracting a predefined handoff parameter as an updated handoff parameter when there is no ping-pong terminal, and a ping-pong for all terminals using a service in a specific cell, if the ping-pong terminal exists. A function of calculating the specific gravity of the terminal, a function of comparing the calculated value with a preset value, and a function of extracting a predefined handoff parameter as an updated handoff parameter when the calculated value is smaller than the preset value and calculating If the value is greater than or equal to the preset value, it may include a function for changing the handoff parameter.

In addition, when performing the function of calculating the specific gravity, it is preferable to calculate the specific gravity of the ping pong terminals that use the packet data service to all the mobile communication terminals using the service in a specific cell.

Thus, those skilled in the art will appreciate that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

According to the present invention, by changing the handoff parameter dynamically according to the radio environment of the cell, it is possible to prevent frequent handoff, thereby improving the quality of service.

In addition, the cell capacity can be increased by suppressing transmission of the measurement report from the mobile communication terminal to the mobile communication system more than necessary, and the waste of radio resources can be suppressed, and as a result, the overall throughput of the cell can be improved. .

Claims (11)

It is connected to a base station controller of a mobile communication system that provides a voice call service or a packet data service to a mobile communication terminal, and receives a measurement report from each mobile communication terminal for a specified time and hands off based on the number of the received measurement reports. And update the parameter and transmit the updated handoff parameter to the base station controller when the preset handoff parameter update time arrives. The method of claim 1, If there is a mobile communication terminal that transmits a measurement report of a predetermined allowable value or more for a predetermined time, the parameter control apparatus moves the transmission of the measurement report of the measured value or more among the mobile communication terminals that use a service in a specific cell. And calculating a specific gravity occupied by the communication terminal and updating the handoff parameter when the specific gravity calculated value is equal to or larger than a preset value. The method of claim 1, The parameter control device includes a control unit for controlling the overall operation; A parameter determining unit for updating the handoff parameter according to the number of measurement reports transmitted from each mobile communication terminal for a specified time; A memory for storing a predefined handoff parameter and a handoff parameter updated by the parameter determiner; A timer for checking whether a handoff parameter update time has arrived; And A parameter change unit for extracting an updated handoff parameter from the memory and transmitting the extracted handoff parameter to the base station controller to request a parameter change when a handoff parameter update time arrives; Parameter control apparatus comprising a. The method of claim 3, wherein The parameter determining unit may include a measurement report collection module which receives a measurement report transmitted for each mobile communication terminal from the base station controller and increments a count each time the measurement report is received; Check whether there is a mobile communication terminal (hereinafter referred to as a "ping-pong terminal") that transmits a measurement report more than a predetermined value for a predetermined time, and if the ping-pong terminal exists, ping-pongs for all mobile communication terminals that are using a service in a specific cell. A specific gravity check module for calculating a specific gravity occupied by the terminal; And When the ping pong terminal is detected as a result of checking the specific gravity check module, and the specific gravity occupies for all mobile communication terminals used by the ping pong terminal in a specific cell is greater than or equal to a preset value, a parameter for updating a predefined handoff parameter Extraction module; Parameter control apparatus comprising a. 5. The method of claim 4, In the parameter extraction module, if the ping pong terminal is not detected or the ping pong terminal is detected, the weight ratio of the ping pong terminal with respect to all mobile communication terminals that are using the service in the specific cell is preset. And when the value is smaller than the value, determine a handoff parameter predefined in the memory as an update parameter. The method according to claim 4 or 5, The specific gravity check module checks whether there is a mobile communication terminal (hereinafter referred to as a 'ping-pong terminal') that transmits a measurement report having a predetermined value or more for a predetermined time period, and when the ping-pong terminal exists, uses a packet data service among the ping-pong terminals. And calculating the proportion of the ping-pong terminal being used to all the mobile communication terminals that are using the service in the specific cell. A handoff parameter control method of a mobile communication terminal connected to a mobile communication system using a voice or packet data service, A first step of receiving a measurement report from each mobile communication terminal for a specified time and extracting and storing handoff parameters according to the number of measurement reports; A second step of confirming whether a handoff parameter update period has arrived; A third step of requesting to change the handoff parameter by transmitting the handoff parameter extracted in the first step to the mobile communication system when a parameter update period arrives as a result of the checking of the second step; And A fourth process of resetting a timer and returning to the first process; Parameter control method comprising a. The method of claim 7, wherein The first step is to collect a measurement report for each mobile communication terminal for a predetermined time, and to determine whether there is a mobile communication terminal (hereinafter referred to as a "ping-pong terminal") that transmits a measurement report more than a predetermined allowable value for a predetermined time. First step; A second step of extracting a predefined handoff parameter as an updated handoff parameter when the ping-pong terminal does not exist as a result of the checking of the first step; A third step of calculating a specific gravity of the ping pong terminals for all the terminals using the service in a specific cell when the ping pong terminals are present as a result of the checking of the first step; A fourth step of comparing the calculated value with a preset value; A fifth step of extracting a predefined handoff parameter as an updated handoff parameter when the calculated value is smaller than the preset value as a result of the comparison in the fourth step; And A sixth step of changing a handoff parameter when the calculated value is greater than or equal to the preset value as a result of the comparison in the fourth step; Parameter control method comprising a. 9. The method of claim 8, The first step may include a first step of increasing a count each time a measurement report is collected for each mobile communication terminal; A first step 1-2 confirming whether a predetermined time has elapsed; As a result of the check of the first step 1-2, if the set time has not elapsed, proceeding to the first step 1-1; And A first to fourth step of checking whether there is a mobile communication terminal which has transmitted a measurement report of a predetermined allowable value or more when the set time has elapsed as a result of the checking of the first and second steps; Parameter control method comprising a. 9. The method of claim 8, The third step is a parameter control method, characterized in that calculating the proportion of the ping-pong terminals using the packet data service of the ping-pong terminals to all the mobile communication terminals using the service in the specific cell. The method of claim 7, wherein If the parameter update period has not arrived as a result of the checking of the second process, the method returns to the first process.

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