KR102128097B1 - Base station apparatus and control method thereof - Google Patents

Abstract

In the present invention, for a terminal (eg, terminal 1) connected to a TDD type base station apparatus, in a connection switching decision process performed when moving to a cell of a different frequency band or a connection switching decision process performed by a load distribution request, We propose an operation method of a base station apparatus and a base station apparatus that can improve the success rate of connection switching between frequency bands of a terminal using a communication service in a TDD manner by allowing the uplink/downlink channel operation ratio of the base station apparatus to be considered.

Description

BASE STATION APPARATUS AND CONTROL METHOD THEREOF}

The present invention relates to a connection switching between frequency bands, and more specifically, an uplink/downlink channel operating ratio may be considered in a process of determining whether a base station operating a frequency band in a TDD scheme switches a connection between frequency bands to a terminal. By making it possible, it relates to a base station apparatus and a method of operating a base station apparatus capable of improving the success rate of connection switching between frequency bands of a terminal using a communication service in a TDD scheme.

The FDD type communication system, which is currently the mainstream of the LTE communication system, adopts a frequency division duplex (FDD) that allocates and divides frequency bands for uplink and downlink channels to communicate. Doing.

The TDD communication system allocates an uplink channel and a downlink channel to the same frequency band, and operates a time division system (TDD: Time Division Duplex) that operates as an uplink channel or a downlink channel according to the uplink/downlink channel operating ratio. Is adopted.

At this time, the maximum transmission rate of the uplink/downlink channel is also determined according to the uplink/downlink channel operating ratio. The general data traffic shows a pattern in which the usage of the downlink channel is larger than the usage of the uplink channel from 2-3 times to 7-8 times. Therefore, in the TDD communication system, it is common to operate in a direction of increasing the ratio of the downlink channel and lowering the ratio of the uplink channel in the uplink/downlink channel operation ratio.

On the other hand, in recent years, as the TDD type LTE communication system is rapidly spreading, a technology has been developed to increase the efficiency of data traffic acceptance by linking the existing LTE-FDD communication system with the LTE-TDD communication system. It is a handover technology between LTE-FDD and LTE-TDD.

Since the LTE-FDD communication system and the LTE-TDD communication system differ only in the physical layer, and the upper layers are the same, the handover process between the LTE-FDD and LTE-TDD is a frequency-to-frequency hand in the LTE-FDD communication system. The process is similar to the over process. That is, when a terminal connected to a serving cell requests a handover by raising a Measurement-Report (MR) to a base station in a situation in which a downlink channel satisfies a specific condition, when the handover condition is satisfied, the base station hands By determining the over, it proceeds as a general process of handing over the terminal to the target cell through interworking with the target cell and the terminal.

However, in the LTE-TDD communication system, the frequency band is operated by increasing the ratio of the downlink channel and lowering the ratio of the uplink channel as described above, and in the general handover process described above, since the terminal is based on the downlink channel, the terminal is LTE. In the case of handover from the TDD communication system to the LTE-FDD communication system, the lower the ratio of the uplink channel, the lower the success rate of handover due to the absence of the uplink channel.

Accordingly, in the present invention, the uplink/downlink channel operating ratio can be taken into account in the handover decision process from the LTE-TDD communication system to the LTE-FDD communication system, so that the UE using the LTE-TDD communication system I would like to propose a way to improve the handover success rate.

The present invention was created in view of the above-described circumstances, and an object of the present invention is to achieve uplink/downlink in the process of determining whether a base station operating a frequency band in a TDD scheme switches access between frequencies to a terminal. By allowing the channel operating ratio to be considered, the success rate of connection switching between frequency bands of a terminal using a communication service in a TDD scheme is improved.

The base station apparatus according to the first aspect of the present invention for achieving the above object, the terminal accessing the terminal through a specific frequency band operated as an uplink channel or a downlink channel according to a preset uplink/downlink channel operating ratio Connections; And an operation ratio applying unit to perform a connection switching decision process to determine whether to switch access to a frequency band other than the specific frequency band for the terminal based on the uplink/downlink channel operating ratio.

Preferably, in the connection switching decision process, based on a downlink signal strength measured by at least one of the specific frequency band and the other frequency band and a predetermined request threshold strength, the terminal moves to the other frequency band. Request to switch access, and the operating ratio applying unit changes and sets the requested threshold strength according to the uplink/downlink channel operation ratio, so that the access switching decision process is performed based on the uplink/downlink channel operation ratio. It can be done.

Preferably, the operating rate applying unit may be set to change the request threshold strength to be higher as the operating rate of the uplink channel is smaller than the downlink channel.

Preferably, in the connection switching decision process, when the base station apparatus requests the connection switching from the terminal, it determines the connection switching to the other frequency band for the terminal based on a predetermined determination threshold strength, The operating ratio applying unit may change the setting threshold strength according to the operating ratio of the uplink/downlink channel, so that the access switching decision process is performed based on the uplink/downlink channel operating ratio.

Preferably, in the connection switching decision process, when the load distribution based on the load state of the specific frequency band and the other frequency band is requested, the base station apparatus may transmit the load to the terminal based on a preset load distribution criterion. The connection switching to the frequency band is determined, and the operating ratio applying unit changes and sets the load distribution standard according to the operating ratio of the uplink/downlink channel, so that the access switching decision process determines the uplink/downlink channel operating ratio. It can be done on a basic basis.

Preferably, the operating ratio applying unit may be configured to change the decision threshold strength or the load distribution criterion to be lower as the operating ratio of the uplink channel is smaller than the downlink channel.

The operation method of the base station apparatus according to the second aspect of the present invention for achieving the above object is through a specific frequency band operated as an uplink channel or a downlink channel according to a preset uplink/downlink channel operating ratio, the terminal and the A terminal access step of accessing; And an operation ratio applying step of performing an access switching decision process for determining whether to switch access to a different frequency band than the specific frequency band to the terminal based on the uplink/downlink channel operating ratio. .

Preferably, in the connection switching decision process, the terminal is based on the downlink signal strength measured for at least one of the specific frequency band and the other frequency band and a preset request threshold strength, to the other frequency band. Requesting to switch access, and in the step of applying the operating rate, the request threshold strength is changed and set according to the operating rate of the uplink/downlink channel, so that the access switching decision process is based on the uplink/downlink channel operating rate. Can be done.

Preferably, in the operation rate application step, the request threshold strength may be changed to be increased as the operation rate of the uplink channel is smaller than that of the downlink channel.

Preferably, in the connection switching decision process, when the base station apparatus requests the connection switching from the terminal, it determines the connection switching to the other frequency band with respect to the terminal based on a predetermined determination threshold strength, In the operation ratio application step, the decision threshold strength may be changed and set according to the operation ratio of the uplink/downlink channel, so that the access switching decision process is performed based on the uplink/downlink channel operation ratio.

Preferably, in the connection switching decision process, when the load distribution based on the load state of the specific frequency band and the other frequency band is requested, the base station apparatus may transmit the load to the terminal based on a preset load distribution criterion. The connection switching to the frequency band is determined, and the operation ratio application step is set by changing the load distribution standard according to the uplink/downlink channel operation ratio, so that the access switching decision process is the uplink/downlink channel operation ratio. It can be performed on the basis of.

Preferably, in the operation ratio application step, the decision threshold strength or the load distribution criterion may be lowered as the operation ratio of the uplink channel is smaller than the downlink channel.

Accordingly, according to the base station apparatus and the operation method of the base station apparatus, the uplink/downlink channel operating ratio is considered in the process of determining whether the base station operating the frequency band in the TDD scheme switches the connection between the frequency bands for the terminal. By making it possible, it is possible to improve the success rate of connection switching between frequency bands of a terminal using a communication service in a TDD scheme.

1 is a configuration diagram showing a communication system including a base station apparatus according to a preferred embodiment of the present invention.
2 is a block diagram showing the configuration of a base station apparatus according to a preferred embodiment of the present invention.
3 is a control flow diagram of a communication system including a base station apparatus according to a preferred embodiment of the present invention.
4 is an operation flowchart showing a method of operating a base station apparatus according to a preferred embodiment of the present invention.

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

1 is a view showing a communication system including a base station apparatus according to a preferred embodiment of the present invention.

As shown in FIG. 1, the communication system includes a base station apparatus 100 according to the present invention and a terminal 1 connected to the base station apparatus 100 to use a communication service.

Of course, although one terminal 1 is illustrated in FIG. 1, there may be a plurality of terminals accessing the base station apparatus 100 in the cell C1 of the base station apparatus 100 to use a communication service. However, hereinafter, for convenience of description, terminal 1 will be described.

The base station apparatus 100 according to the present invention is preferably a base station that supports the TDD scheme.

That is, the base station apparatus 100 allocates an uplink channel and a downlink channel to the same frequency band, and operates a time division scheme operating as an uplink channel or a downlink channel according to a preset up/downlink channel operating ratio (TDD: Time Division Duplex).

In this case, the base station apparatus 100 generally increases the ratio of the downlink channel in the uplink/downlink channel operating ratio and increases the uplink channel data rate due to the fact that the downlink channel data traffic is more than the uplink channel data traffic. It is common to operate in a direction that lowers the ratio.

For example, the base station apparatus 100 may set the uplink/downlink channel operating ratio to 1:3.

Accordingly, the base station apparatus 100 operates the uplink/downlink channel according to a preset up/downlink channel operating ratio, i.e., 1:3, of a specific frequency band to which the terminal 1 is connected, thereby providing communication service to the terminal 1. Can provide.

Meanwhile, when the terminal 1 moves from the cell C1 of the base station apparatus 100 to another adjacent cell C2, for example, the cell C2 of the other base station apparatus 200, the terminal 1 and the base station apparatus 100 end the terminal 1 For the connection switching decision process to determine whether to switch the connection to another cell (C2) will be performed.

On the other hand, the load distribution between the cell (C1) and the cell (C2) in the central device (not shown) that manages the load state for the cell (C1) of the base station apparatus 100 and the cell (C2) of the other base station apparatus 200 If load distribution is requested according to the determination that this is necessary, the base station apparatus 100 determines whether to switch to the other cell (C2) for each of a plurality of terminals connected to itself, including terminal 1 The process will be carried out.

Here, the base station apparatus 200 forming the cell C2 is a base station using a frequency band other than a specific frequency band of the base station apparatus 100, and may support a TDD scheme or use a Frequency Division Duplex (FDD) scheme. You can apply.

Hereinafter, for convenience of description, the base station apparatus 200 forming the cell C2 will be described as referring to supporting the FDD scheme.

However, as described above, for a terminal (eg, terminal 1) connected to the cell C1 of the base station apparatus 100 of the TDD method, a connection switching determination process performed when moving to a cell C2 of another frequency band or In the connection switching decision process performed by the load distribution request, since the uplink/downlink channel operating ratio of the base station apparatus 100 is not considered, the lower the uplink channel ratio is operated, the more the access is due to the absence of the uplink channel. There is a problem that the conversion success rate is falling.

In order to solve this problem, in the present invention, as described above, for a terminal (eg, terminal 1) connected to the cell C1 of the base station apparatus 100 of the TDD method, moving to a cell C2 of a different frequency band In the case of performing the connection switching decision process performed by the load conversion request or the connection switching decision process performed by the load distribution request, the uplink/downlink channel operating ratio of the base station apparatus 100 may be considered.

Hereinafter, a configuration of a base station apparatus according to a preferred embodiment of the present invention will be described in more detail with reference to FIG. 2. For convenience of description, description will be made using reference numbers mentioned in FIG. 1 above.

The base station apparatus 100 according to the present invention includes a terminal access unit 110 accessing a terminal through a specific frequency band operated as an uplink channel or a downlink channel according to a preset uplink/downlink channel operating ratio, and the On the basis of the uplink/downlink channel operating ratio, an operating ratio applying unit 130 for performing a connection switching decision process to determine whether to switch access to a frequency band other than the specific frequency band to the terminal is performed. do.

In addition, the base station apparatus 100 according to the present invention may further include a connection switching performing unit 120.

The base station apparatus 100 is a base station supporting the TDD scheme as described above, and an uplink channel according to a preset uplink/downlink channel operating ratio, for example, 1:3, for each of a plurality of terminals connected through a specific frequency band. Or, by operating a specific frequency band on a downlink channel, communication services can be provided to each terminal.

Hereinafter, terminal 1 will be referred to as representative of a plurality of terminals connected to the base station apparatus 100.

That is, the terminal access unit 110 accesses terminal 1 through a specific frequency band operated as an uplink channel or a downlink channel according to a preset uplink/downlink channel operating ratio.

The operating ratio applying unit 130, based on the operating ratio of the uplink/downlink channel, allows the terminal 1 to perform a connection switching decision process to determine whether to switch access to a different frequency band than the specific frequency band. .

More specifically, as described above, when the terminal 1 moves from the cell C1 of the base station apparatus 100 to another adjacent cell C2, for example, a cell C2 of another frequency band, the terminal 1 and the base station apparatus 100 ), the connection switching determining unit 120 will perform the connection switching decision process to determine whether to switch the connection to the other cell C2 for the terminal 1.

On the other hand, the load distribution between the cell (C1) and the cell (C2) in the central device (not shown) that manages the load state for the cell (C1) of the base station apparatus 100 and the cell (C2) of the other base station apparatus 200 When the load distribution is determined to be necessary, the connection switching execution unit 120 of the base station apparatus 100 switches the connection to another cell C2 for each of a plurality of terminals connected to itself, including terminal 1 A connection switching decision process will be performed to determine whether or not.

First, as described above, for the terminal 1 connected to the cell C1 of the base station apparatus 100 of the TDD scheme, a cell C2 of a different frequency band, for example, another frequency band cell C2 of the base station apparatus 200 of the FDD scheme In the case of moving to ), the connection switching decision process to be performed will be described.

In this case, the connection switching decision process may be divided into a process in which the terminal 1 requests a connection switch and a process in which the base station apparatus 100 determines a connection switch to the terminal 1.

First, when the process of requesting the connection to be switched by the terminal 1 in the connection switching decision process, the terminal 1 measures the downlink signal strength measured for at least one of a specific frequency band and other frequency bands of the base station apparatus 100 currently being accessed. Based on the previously set request threshold strength, request to switch the connection to the other frequency band.

In more detail, a typical existing base station, for each of a plurality of terminals connected to itself, periodically provides system information (SI) at the beginning or after the connection. You can drop it off with a request TH).

Accordingly, the terminal pre-sets the request threshold strength (fixed request TH) provided from the base station.

In addition, the UE continuously measures and measures the downlink signal strength of the currently accessed base station, that is, the downlink signal strength of another cell adjacent to the downlink signal strength for a specific frequency band, that is, the downlink signal strength for another frequency band. According to the comparison result comparing the downlink signal strength with the requested threshold strength of the preset tactic, it is determined whether the downlink channel satisfies a specific condition.

For example, the terminal compares the downlink signal strength of the currently accessed base station with a preset request threshold strength (fixed request TH), and the downlink signal strength of the base station is less than or equal to the requested threshold strength (fixed request TH). , It is determined that the downlink channel satisfies a specific condition, and at this point, it is possible to request a switchover or handover to another cell by raising a measurement-report (MR) containing the downlink signal strengths measured above to the base station. have. Hereinafter, this time will be referred to as a time when the terminal requests connection switching.

At this time, in the present invention, the request threshold strength set in the terminal is changed according to the uplink/downlink channel operating ratio, so that the access switching decision process is performed based on the uplink/downlink channel operating ratio.

That is, the operation ratio applying unit 130 changes the request threshold strength preset in the terminal 1 according to the up/down link channel operation ratio, so that the access switching decision process for the terminal 1 is based on the up/down link channel operation ratio. Can be performed with

For example, the operating ratio applying unit 130, before transmitting the fixed request threshold strength (fixed request TH) to the terminal 1 on the SI as described above, instead of the fixed request threshold strength (fixed request TH) / By setting the requested threshold strength (change request TH) changed according to the downlink channel operation ratio and transmitting it to the terminal 1, the terminal 1 can set the changed requested threshold strength (change request TH).

At this time, the operation ratio applying unit 130, in setting and changing the request threshold strength, the smaller the operation ratio of the uplink channel compared to the downlink channel, the higher the request threshold strength can be set to change.

For example, the formula for changing the requested threshold strength in the operating ratio applying unit 130 may be as shown in Equation 1 below.

Equation 1.

Request Threshold (Change Request TH) = Request Threshold (Fix Request TH) ± Change Offset

In this case, whether to apply the change offset as + or-in Equation 1 depends on whether the connection is switched from the TDD cell to the FDD cell or from the FDD cell to the TDD cell. Follow. That is, in Equation 1, it can be applied as + in the case of TDD -> FDD, and as-in the case of FDD -> TDD.

Accordingly, the operating ratio applying unit 130 of the TDD-based base station apparatus 100 applies the change offset obtained by converting the uplink/downlink channel operation ratio to dB in Equation 1 to +, thereby increasing the uplink compared to the downlink channel. It is possible to obtain a request threshold strength (change request TH) to be set to be changed so that the link channel operation rate is increased as the operation rate is small.

For example, as described above, assuming that the uplink/downlink channel operation ratio is 1:3 and the request threshold strength (fixed request TH) is -20dB, the operation ratio applying unit 130 operates the uplink/downlink channel A change offset can be obtained based on a ratio of 1:3.

For example, the operating ratio applying unit 130 may obtain a change offset by converting the uplink/downlink channel operation ratio 1:3 to dB, or the scaling value at the uplink/downlink channel operation ratio 1:3. A change offset can be obtained by converting the value multiplied by (scaling factor) to dB, or a difference (eg, 3-1=2) of the uplink/downlink channel operation ratio 1:3 is obtained to obtain the change offset. You may.

Hereinafter, for convenience of description, an embodiment will be described with reference to a case where a change offset is obtained by converting an uplink/downlink channel operation ratio of 1:3 to dB.

That is, the operating ratio applying unit 130 applies the change offset 4.5 dB obtained by converting the uplink/downlink channel operating ratio 1:3 to dB as + to Equation 1, so that the request threshold strength to be changed (change request TH ) To get -15.5dB.

At this time, if the uplink/downlink channel operation ratio is 1:7 and the uplink channel operation ratio is smaller than the downlink channel, the change offset obtained by converting the uplink/downlink channel operation ratio to dB is 1:3. It will be bigger than the case, and as a result, it will be smaller than the case where the set request threshold strength (change request TH) is 1:3.

Accordingly, the terminal 1 will be set to 15.5dB of the requested threshold strength (change request TH) set according to the uplink/downlink channel operating ratio, not the existing fixed request threshold strength (fixed request TH) -20dB.

Accordingly, if the terminal 1 moves from the cell C1 of the base station apparatus 100 to another adjacent cell C2 as described above, the terminal 1 base station apparatus based on the changed set request threshold strength (change request TH) 15.5dB. If the downlink signal strength of (100) is less than or equal to the requested threshold strength (request to change TH) of 15.5 dB, it is determined that the downlink channel satisfies a specific condition, and at this point, the measured downlink signal strengths are included. The MR is raised to the base station apparatus 100 to request connection switching to another cell, that is, handover.

After all, according to the present invention, when the terminal 1 requests to switch access in the process of determining the connection switch to the terminal 1, the request threshold strength (fixed request TH) without considering the uplink/downlink channel operating ratio is set. It will be faster.

If the base station apparatus 100 of the present invention supports the FDD scheme and the base station apparatus 200 supports the TDD scheme, the operating ratio applying unit 130 of the FDD scheme base station apparatus 100, the request threshold strength In the change setting, the smaller the operation rate of the uplink channel compared to the downlink channel, the lower the time point for requesting the connection switch from the terminal 1 by setting the change so that the request threshold strength is lowered.

That is, the operating ratio applying unit 130 requests the threshold strength (fixed request TH) of the modified offset 4.5 dB obtained by converting the uplink/downlink channel operation ratio of the base station apparatus 100, for example, 1:3 into dB. ) Is applied to -20dB as-to obtain -24.5dB as the request threshold strength (change request TH) to be changed.

Accordingly, the terminal 1 may be set with the requested threshold strength (change request TH) -24.5dB set according to the uplink/downlink channel operating ratio rather than the existing fixed request threshold strength (fixed request TH) -20dB, and eventually In the process of deciding the connection switching to the terminal 1, the time when the terminal 1 requests to switch the connection is delayed.

On the other hand, when the process of determining the connection switching to the terminal 1 in the TDD-based base station apparatus 100 in the above-described connection switching decision process, the connection switching execution unit 120, the connection switching from the terminal 1 as described above If requested, the connection switching to the other frequency band is determined for the terminal 1 based on the predetermined decision threshold strength.

For example, when the connection switching or handover is requested as described above from the terminal 1, the connection switching performing unit 120 checks the downlink signal strength for the other frequency bands included in the MR received together, that is, the cell C2. , In the same manner as in the previous method, if the downlink signal strength of the cell C2 is equal to or greater than a predetermined threshold threshold, the handover condition is determined to be satisfied, and the UE 1 is switched to the cell C2, that is, to another frequency band. And, if the downlink signal strength of the cell C2 is not greater than a predetermined threshold threshold strength, it can be determined that the terminal 1 does not switch access to the cell C2, that is, to another frequency band.

At this time, in the present invention, by changing the predetermined threshold strength according to the operating ratio of the uplink / downlink channel, the connection switching decision process is to be performed based on the uplink / downlink channel operating ratio.

That is, the operating rate applying unit 130 changes the existing fixed decision threshold strength (fixed decision TH) preset in the connection switching performing unit 120 according to the operating rate of the uplink/downlink channel, and accesses the terminal. The conversion decision process can be performed based on the uplink/downlink channel operating ratio.

At this time, the operating ratio applying unit 130, in setting and changing the decision threshold strength, it is preferable to set the change so that the decision threshold strength is lower as the operating ratio of the uplink channel is smaller than the downlink channel.

For example, the formula for changing and setting the critical threshold strength in the operating ratio applying unit 130 may be as shown in Formula 2 below.

Equation 2.

Decision threshold strength (change decision TH) = crystal threshold strength (fixed decision TH) ± change offset

In this case, whether to apply the change offset as + or-in Equation 2 depends on whether the connection is switched from the TDD cell to the FDD cell or the FDD cell to the TDD cell. Follow. That is, in Equation 1, it can be applied as-in the case of TDD -> FDD, and as + in the case of FDD -> TDD.

Accordingly, the operating ratio applying unit 130 of the TDD-based base station apparatus 100 applies the change offset obtained by converting the uplink/downlink channel operation ratio to dB in Equation 2, and applies uplink to the downlink channel by using Equation (2). Decision threshold strength (change decision TH) can be obtained to be changed so that the lower the operating ratio of the channel, the lower it is.

For example, assuming that the uplink/downlink channel operating ratio is 1:3 as described above, and assuming that the decision threshold strength (fixed decision TH) is 25dB, the operating ratio applying unit 130, the uplink/downlink channel operating ratio By applying 4.5dB of the change offset obtained by converting 1:3 to dB, we can obtain 20.5dB as the decision threshold strength (change decision TH) to be changed by applying -2 to Equation 2.

At this time, if the uplink/downlink channel operation ratio is 1:7 and the uplink channel operation ratio is smaller than the downlink channel, the change offset obtained by converting the uplink/downlink channel operation ratio to dB is 1:3. It will be larger than the case, and as a result, it will be smaller than the case where the change-established crystal threshold strength (change decision TH) is 1:3.

Accordingly, in the connection switching execution unit 120, the determined threshold strength (change decision TH) 20.5 dB is set in accordance with the up/down link channel operating ratio, not the existing fixed decision threshold strength (fixed decision TH) 25 dB. .

Therefore, when the connection switching or handover is requested as described above from the terminal 1, the connection switching performing unit 120 checks the downlink signal strength for the other frequency bands included in the MR received together, that is, the cell C2. , If the downlink signal strength of the cell C2 is the set threshold threshold (change decision TH) of 20.5 dB or more in the same manner as before, it is determined that the handover condition is satisfied. It will decide to switch the connection to the band.

After all, according to the present invention, when the base station apparatus 100 determines the access switch in the process of determining the access switch to the terminal 1, the decision threshold strength (fixed decision TH) without considering the uplink/downlink channel operating ratio is It will be faster than when it is set.

On the other hand, as described above, for the terminal 1 connected to the cell C1 of the base station apparatus 100 of the TDD method, the connection switching determination process performed by the load distribution request will be described.

The connection switching determination process in this case includes a process of determining whether to switch access to each of a plurality of terminals accessed by the base station apparatus 100.

In more detail, the connection switching performing unit 120 is a central device (not shown) that manages the load state on the cell C1 of the base station apparatus 100 and the cell C2 of the other base station apparatus 200. If load distribution is requested according to the determination that load distribution between cells C1 and C2 is necessary, based on a preset load distribution criterion, different frequency bands are used for each terminal connected to the base station apparatus 100. The connection switching to the cell C2 is determined.

That is, when referring to terminal 1 among a plurality of terminals connected to the base station apparatus 100, the terminal access switching performing unit 120 loads the downlink information of terminal 1 based on the load balancing criteria set in advance. If the criteria are met, the cell 1 is determined to switch to the cell C2, that is, to another frequency band. If the downlink information of the terminal 1 does not meet the load distribution criterion, the cell C2 to the terminal 1, that is, another frequency band. You can decide not to switch connections to.

At this time, in the present invention, by changing the preset load distribution criteria according to the up/down link channel operating ratio, the connection switching decision process is to be performed based on the up/down link channel operating ratio.

That is, the operating ratio applying unit 130 changes the existing fixed load distribution standard (fixed load TH) preset in the connection switching performing unit 120 according to the operating ratio of the uplink/downlink channel, and determines the connection switching process. It can be performed based on the uplink/downlink channel operating ratio.

At this time, the operating ratio applying unit 130, in setting and changing the load distribution criteria, it is preferable to change the setting so that the load distribution criterion is lower as the operating ratio of the uplink channel is smaller than the downlink channel.

Accordingly, in the connection switching execution unit 120, the load distribution criterion (changed load TH) set according to the uplink/downlink channel operating ratio is set instead of the existing fixed load distribution criterion (fixed load TH).

Therefore, the connection switching execution unit 120 changes the downlink information of the terminal 1 when load distribution is requested by the central device (not shown) when it is determined that load distribution between the cells C1 and C2 is necessary. If the set load distribution criterion (changed load TH) is met, the UE 1 will decide to switch access to another cell C2, that is, to a different frequency band.

After all, according to the present invention, when the base station apparatus 100 determines the connection switching in the process of determining the connection switching to the terminal 1, the load distribution criterion (fixed load TH) without considering the uplink/downlink channel operating ratio is It will be faster than when it is set.

As described above, according to the base station apparatus according to the present invention, for a terminal (eg, terminal 1) connected to a TDD-based base station apparatus, a connection switching decision process or load distribution request performed when moving to a cell in a different frequency band In the access switching decision process performed by the base station, the uplink/downlink channel operating ratio of the base station apparatus can be considered, so that the success rate of access switching between the frequency bands of the terminal using the communication service in the TDD scheme can be improved.

Hereinafter, an operation method of the base station apparatus according to the present invention will be described with reference to FIGS. 3 to 4. For convenience of description, description will be made using reference numbers mentioned in FIGS. 1 and 2 above.

First, referring to FIG. 3, the control flow of the communication system including the base station apparatus according to the present invention will be described.

The base station apparatus 100 is a base station supporting the TDD scheme as described above, and an uplink channel according to a preset uplink/downlink channel operating ratio, for example, 1:3, for each of a plurality of terminals connected through a specific frequency band. Alternatively, by operating a specific frequency band on a downlink channel, communication services can be provided to each terminal.

Accordingly, when terminal 1 is connected to the base station apparatus 100, the base station apparatus 100 operates a specific frequency band as an uplink channel or a downlink channel according to a preset uplink/downlink channel operation ratio, for example, 1:3. , It may provide a communication service to the terminal 1 (S20).

At this time, as described above, when the terminal 1 moves from the cell C1 of the base station apparatus 100 to another adjacent cell C2, for example, a cell C2 of a different frequency band, the terminal 1 and the base station apparatus 100 end the terminal. A connection switching determination process for determining whether to switch the connection to another cell C2 for 1 will be performed.

On the other hand, the load distribution between the cell (C1) and the cell (C2) in the central device (not shown) that manages the load state for the cell (C1) of the base station apparatus 100 and the cell (C2) of the other base station apparatus 200 If load distribution is requested according to the determination that this is necessary, the base station apparatus 100 terminal will perform a connection switching decision process to determine whether to switch the terminal 1 to another cell (C2).

Hereinafter, as the load distribution is requested in response to determining that the load distribution between the cell C1 and the cell C2 is required in the central apparatus (not shown), the base station apparatus 100 terminal determines the connection switching process for the terminal 1 This disclosed case will be described (S30 Yes).

In this case, the base station apparatus 100 pre-receives downlink information related to downlink signal strength and reception success rate of the base station apparatus 100 from the terminal 1 (S40).

The base station apparatus 100 changes and sets a preset fixed load distribution criterion (fixed load TH) according to the uplink/downlink channel operating ratio (S50).

At this time, the base station apparatus 100, in setting and changing the load distribution criterion, it is preferable to change the load distribution criterion to be lower as the operating ratio of the uplink channel is smaller than the downlink channel.

Accordingly, the base station apparatus 100 will be set with a load distribution criterion (modified load TH) set according to the uplink/downlink channel operating ratio rather than the existing fixed load distribution criterion (fixed load TH).

Therefore, the base station apparatus 100, on the basis of the change set load distribution criteria (changed load TH), if the downlink information of the terminal 1 meets the load distribution criteria, the cell 1 for the terminal 1, C2, that is, to a different frequency band If the connection switching is determined and the downlink information of the terminal 1 does not meet the load distribution criterion, it may be determined that the terminal 1 does not switch the connection to the cell C2, that is, to another frequency band (S60).

That is, when the downlink information of the terminal 1 meets the changed load distribution criterion (changed load TH), the base station apparatus 100 will determine the connection switching to the other cell C2, that is, another frequency band, for the terminal 1.

Hereinafter, an operation method of a base station apparatus according to a preferred embodiment of the present invention will be described in detail with reference to FIG. 4.

And, since the connection switching decision process according to the load distribution request is described in FIG. 3, in FIG. 4, the terminal 1 connected to the cell C1 of the base station apparatus 100 moves to a cell C2 of a different frequency band. In this case, the connection switching decision process performed will be described.

The operation method of the base station apparatus 100 according to the present invention, a plurality of terminals are connected (S100), the uplink channel according to a preset up/downlink channel operating ratio for a plurality of connected terminals, for example 1:3 or By operating a specific frequency band on a downlink channel, communication services can be provided to each terminal (S110).

Hereinafter, terminal 1 will be referred to as representative of a plurality of terminals connected to the base station apparatus 100.

The operation method of the base station apparatus 100 according to the present invention is set to change the requested threshold strength to be transmitted to the terminal 1 on the SI according to the up/down link channel operating rate as described above (S120).

At this time, in the operation method of the base station apparatus 100 according to the present invention, in setting and changing the request threshold strength, it is preferable to change and set the request threshold strength to be higher as the operation ratio of the uplink channel to the downlink channel is smaller. .

For example, in the operation method of the base station apparatus 100 according to the present invention, the request threshold strength set to be changed by applying the change offset obtained by converting the uplink/downlink channel operating rate to dB in Equation 1 above (+) You can get the change request TH).

For example, assuming that the uplink/downlink channel operating ratio is 1:3 as described above, and the request threshold strength (fixed request TH) is -20dB, the operation method of the base station apparatus 100 according to the present invention is upward / By applying the change offset 4.5dB obtained by converting the downlink channel operation ratio to 1:3 in dB as + in Equation 1, -15.5dB can be obtained as the request threshold strength (change request TH) to be set.

At this time, if the uplink/downlink channel operation ratio is 1:7 and the uplink channel operation ratio is smaller than the downlink channel, the change offset obtained by converting the uplink/downlink channel operation ratio to dB is 1:3. It will be bigger than the case, and as a result, it will be smaller than the case where the set request threshold strength (change request TH) is 1:3.

As described above, the operation method of the base station apparatus 100 according to the present invention is a fixed request threshold strength (fixed request TH) before transmitting the fixed request threshold strength (fixed request TH) to the terminal 1 on the SI as described above. ) Instead, the request threshold strength (change request TH) set in accordance with the uplink/downlink channel operation ratio is transmitted to the terminal 1 by loading it on the SI, so that the terminal 1 can set the changed request threshold strength (change request TH).

Accordingly, the terminal 1 will be set to 15.5dB of the requested threshold strength (change request TH) set according to the uplink/downlink channel operating ratio, not the existing fixed request threshold strength (fixed request TH) -20dB.

In addition, the operation method of the base station apparatus 100 according to the present invention is to change the preset fixed fixed threshold strength (fixed decision TH) according to the up/down link channel operating ratio (S130), and access to the terminal The conversion decision process can be performed based on the uplink/downlink channel operating ratio.

At this time, in the operation method of the base station apparatus 100 according to the present invention, in changing and setting the decision threshold strength, the smaller the operating ratio of the uplink channel compared to the downlink channel, the operation of the base station apparatus 100 according to the present invention In the method, it is desirable to set the change so that the critical strength is low.

For example, in the operation method of the base station apparatus 100 according to the present invention, the decision threshold strength to be changed is set by applying the change offset obtained by converting the uplink/downlink channel operating ratio to dB in Equation 2 above. Change decision TH).

For example, assuming that the up/down link channel operating ratio is 1:3 as described above, and the critical threshold strength (fixed decision TH) is 25dB, the operation method of the base station apparatus 100 according to the present invention is up/ By applying the change offset 4.5dB obtained by converting the downlink channel operation ratio to 1:3 in dB as -2 in Equation 2, it is possible to obtain 20.5dB as the decision threshold strength (change decision TH) to be changed.

At this time, if the uplink/downlink channel operation ratio is 1:7 and the uplink channel operation ratio is smaller than the downlink channel, the change offset obtained by converting the uplink/downlink channel operation ratio to dB is 1:3. It will be larger than the case, and as a result, it will be smaller than the case where the change-established crystal threshold strength (change decision TH) is 1:3.

Accordingly, in the operation method of the base station apparatus 100 according to the present invention, the determined threshold strength (change decision TH) 20.5 is set according to the uplink/downlink channel operating ratio, not the existing fixed decision threshold strength (fixed decision TH) 25dB. dB will be set.

Thereafter, if the terminal 1 moves from the cell C1 of the base station apparatus 100 to another adjacent cell C2 as described above, the terminal 1 sets the changed request threshold strength (change request TH) 15.5dB as described above. As a basis, if the downlink signal strength of the base station apparatus 100 is less than or equal to the requested threshold strength (change request TH) of 15.5 dB, it is determined that the downlink channel satisfies a specific condition, and the downlink signal measured above is determined at this point. The MRs including the strengths will be raised to the base station apparatus 100 to request connection switching to another cell, i.e., handover (S140).

After all, according to the present invention, when the terminal 1 requests to switch access in the process of determining the connection switch to the terminal 1, the request threshold strength (fixed request TH) without considering the uplink/downlink channel operating ratio is set. It will be faster.

Accordingly, in the operation method of the base station apparatus 100 according to the present invention, when connection switching, that is, handover is requested from the terminal 1 as described above (S150 Yes), other frequency bands included in the MR received together, that is, the cell C2 Checking the downlink signal strength for, and in the same manner as in the previous method, if the downlink signal strength of the cell C2 is set to be greater than or equal to the set threshold threshold (change decision TH) 20.5 dB, it is determined that the handover condition is satisfied and the terminal 1 With respect to cell C2, that is, connection switching to another frequency band will be determined (S160).

After all, according to the present invention, when the base station apparatus 100 determines the access switch in the process of determining the access switch to the terminal 1, the decision threshold strength (fixed decision TH) without considering the uplink/downlink channel operating ratio is It will be faster than when it is set.

Thereafter, if the operation method of the base station apparatus 100 according to the present invention is performed by performing a subsequent process on the terminal 1, it is determined that the connection is switched to the cell C2, that is, to another frequency band in the connection switching decision process described above. Through the interworking with the base station apparatus 200 of the cell C2 and the terminal 1, the terminal 1 will be switched or handed over to the cell C2, and the cell C2, i.e., to another frequency band in the connection switching decision process described above. If it is determined that the connection is not switched, the terminal 1 will not be switched over to the cell C2, i.e., not handed over (S170).

As described above, according to an operation method of a base station apparatus according to the present invention, a connection switching determination process performed when a terminal (eg, terminal 1) connected to a base station apparatus of the TDD scheme moves to a cell of a different frequency band or In the connection switching decision process performed by the load distribution request, the uplink/downlink channel operating ratio of the base station device can be considered, so that the success rate of connection switching between the frequency bands of the terminal using the communication service in the TDD scheme can be improved. have.

The method of operating a base station apparatus according to an embodiment of the present invention may be implemented in a form of program instructions that can be executed through various computer means and may be recorded on a computer readable medium. The computer-readable medium may include program instructions, data files, data structures, or the like alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the present invention, or may be known and usable by those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs, DVDs, and magnetic media such as floptical disks. Includes hardware devices specifically configured to store and execute program instructions such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language code that can be executed by a computer using an interpreter, etc., as well as machine language codes produced by a compiler. The hardware device described above may be configured to operate as one or more software modules to perform the operation of the present invention, and vice versa.

The present invention has been described in detail with reference to preferred embodiments, but the present invention is not limited to the above-described embodiments, and the technical field to which the present invention pertains without departing from the gist of the present invention claimed in the claims below. Anyone with ordinary knowledge in the technical idea of the present invention extends to the extent that various modifications or modifications are possible.

According to the base station apparatus and the operation method of the base station apparatus according to the present invention, the uplink/downlink channel operating ratio may be considered in the process of determining whether the base station operating the frequency band in the TDD scheme switches access between the frequency bands to the terminal. In order to improve the success rate of connection switching between frequency bands of a terminal using a communication service in a TDD manner, as it exceeds the limitations of the existing technology, it is not only the use of the related technology but also the marketing or sales of the applied device. It is an invention that has industrial applicability because it is not only possible but also practically clear.

1: terminal
C1, C2: Cell
100: base station device

Claims (12)

A terminal access unit accessing the terminal through a specific frequency band operated as an uplink channel or a downlink channel according to a preset uplink/downlink channel operating ratio; And
Based on the operating ratio of the uplink/downlink channel, an operating ratio is applied to the terminal to perform a connection switching decision process to determine whether to switch access from the specific frequency band to a frequency band other than the specific frequency band. Base station apparatus comprising a unit. According to claim 1,
In the connection switching decision process,
The terminal requests a connection switch to the other frequency band based on a downlink signal strength and a preset request threshold strength measured for at least one of the specific frequency band and the other frequency band,
The operating ratio application unit,
A base station apparatus characterized in that the request threshold strength is changed and set according to the uplink/downlink channel operating ratio, so that the access switching decision process is performed based on the uplink/downlink channel operating ratio. According to claim 2,
The operating ratio application unit,
The base station apparatus, characterized in that the smaller the operating ratio of the uplink channel compared to the downlink channel, the higher the request threshold strength is set. According to claim 1,
In the connection switching decision process,
When the base station apparatus requests the connection to be switched from the terminal, it determines the connection switching to the other frequency band with respect to the terminal based on a predetermined determination threshold strength,
The operating ratio application unit,
A base station apparatus characterized in that the decision threshold strength is changed and set according to the uplink/downlink channel operating ratio, so that the access switching decision process is performed based on the uplink/downlink channel operating ratio. According to claim 1,
In the connection switching decision process,
When a load distribution based on the load state of the specific frequency band and the other frequency band is requested, the base station apparatus determines connection switching to the other frequency band for the terminal based on a preset load distribution criterion,
The operating ratio application unit,
A base station apparatus characterized in that the load distribution criterion is changed and set according to the uplink/downlink channel operating ratio, so that the access switching decision process is performed based on the uplink/downlink channel operating ratio. The method of claim 4,
The operating ratio application unit,
The base station apparatus, characterized in that the smaller the operating ratio of the uplink channel compared to the downlink channel, the lower the decision threshold strength is set. A terminal access step of accessing a terminal through a specific frequency band operated as an uplink channel or a downlink channel according to a preset uplink/downlink channel operating ratio; And
Based on the operating ratio of the uplink/downlink channel, an operating ratio is applied to the terminal to perform a connection switching decision process to determine whether to switch access from the specific frequency band to a frequency band other than the specific frequency band. Method of operation of a base station apparatus comprising a step. ◈ Claim 8 was abandoned when payment of the set registration fee was made.◈ The method of claim 7,
In the connection switching decision process,
The terminal requests a connection switch to the other frequency band based on a downlink signal strength and a preset request threshold strength measured for at least one of the specific frequency band and the other frequency band,
The operation ratio application step,
A method of operating a base station apparatus, characterized in that the request threshold strength is changed and set according to the uplink/downlink channel operating ratio, so that the access switching decision process is performed based on the uplink/downlink channel operating ratio. ◈ Claim 9 was abandoned when payment of the set registration fee was made.◈ The method of claim 8,
The operation ratio application step,
A method of operating a base station apparatus, characterized in that the smaller the operating ratio of the uplink channel compared to the downlink channel, the higher the request threshold strength is set. ◈ Claim 10 was abandoned when payment of the set registration fee was made.◈ The method of claim 7,
In the connection switching decision process,
When the base station apparatus requests the connection switch from the terminal, it determines the connection switch to the other frequency band with respect to the terminal based on the predetermined threshold threshold strength,
The operation ratio application step,
A method of operating a base station device, characterized in that the decision threshold strength is changed and set according to the uplink/downlink channel operating ratio, so that the access switching decision process is performed based on the uplink/downlink channel operating ratio. ◈ Claim 11 was abandoned when payment of the set registration fee was made.◈ The method of claim 7,
In the connection switching decision process,
When the base station apparatus requests load distribution based on the load condition of the specific frequency band and the other frequency band, it determines the connection switching to the other frequency band for the terminal based on a preset load distribution criterion,
The operation ratio application step,
A method of operating a base station apparatus, characterized in that the load distribution criterion is changed and set according to the uplink/downlink channel operating ratio, so that the access switching decision process is performed based on the uplink/downlink channel operating ratio. ◈ Claim 12 was abandoned when payment of the set registration fee was made.◈ The method of claim 10,
The operation ratio application step,
A method of operating a base station apparatus, characterized in that the smaller the operating ratio of the uplink channel compared to the downlink channel, the lower the determination threshold strength becomes.

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