TW201929570A - Method for adjusting switch parameter according to hand out success eate - Google Patents

Abstract

A base station switch parameter adjusting method, comprising: (a) calculating a plurality of hand out success rates of a source base station handing out to a plurality of neighboring base stations of the source base station; (b) classifying the hand out success rates to a plurality of levels, and setting switching parameters of the neighboring base stations according to the levels; and (c) controlling at least one hand out operation from the source base station to the neighboring stations according to the switching parameters. The switching parameters affect a tendency of the source base station handing out to the neighboring base stations.

Description

Method for adjusting switching parameters according to cut-out success rate

The present invention relates to a handover of a base station, and more particularly to a method for adjusting a handover parameter according to a cutout success rate.

User Equipment (UE) will switch between different base stations to maintain good communication quality. Taking Figure 1 as an example, when the signal strength provided by the base station A_a that provides communication for the user equipment U is too low, a handover is performed to connect the user equipment U to the base station A_b with a stronger signal strength. Triggering of handover can be based on signal strength or other parameters, but the trigger conditions are difficult to set perfectly. Whether the trigger is triggered too early or too late, it may affect the user experience. Therefore, an innovative base station handover method is needed to improve the foregoing. The problem.

An object of the present invention is to provide a base station handover method that can adjust handover parameters without a connection between base stations.

An embodiment of the present invention provides a method for adjusting a handover parameter of a base station, including: (a) calculating a success rate of switching out of a plurality of neighboring base stations from a source base station to the source base station; Classify the levels, and set the handover parameters of the plurality of neighboring base stations according to the plurality of levels; and (c) control the cut-out action from the source base station to the plurality of neighboring base stations according to the plurality of handover parameters. The plurality of handover parameters affect the tendency of switching from the source base station to the plurality of neighboring base stations.

According to the foregoing embodiment, since the handover parameters are adjusted according to the cut-out success rate, the user equipment is more likely to be handed over to a base station with a higher handover success rate, and data does not need to be transmitted through the connection between the base stations, so it can be transmitted between base stations. When there is no connection, the switching action is optimized, and the switching action can be optimized according to the cut-out success rate instead of the error information, which can avoid the problems in the prior art.

There is usually a many-to-many relationship between user equipment and base stations. Taking Figure 2 as an example, user equipment U_1 ... U_m is originally served by base station A_0, and base stations A_1 ... A_n are neighboring base stations of base station A_0. In this example, any of the user equipment U_1 ... U_m may be switched from the base station A_0 to any of the base stations A_1 ... A_n, and m and n are both positive integers greater than or equal to 1. For example, user equipment U_1 handovers from base station A_0 to base station A_1. This action is hand-out or handover out for base station A_0, and hand-in or handover in for base station A_1. The base station A_0 may be called a source base station, and the base station A_1 may be called a target base station. The following describes the embodiments of the present invention from the perspective of a source base station (for example, A_0 in FIG. 2).

FIG. 3 is a schematic flowchart of a method for triggering a handover parameter adjustment according to an embodiment of the present invention. In the schematic diagram of FIG. 3, when the trigger time of the handover parameter adjustment is reached in step 301, it proceeds to step 303 to reset the trigger time, and then proceeds to step 305 to start adjusting the handover parameter. For example, if you set the switching parameter once every 1 hour, a timer will start counting from zero. When the timer reaches 1 hour, the timer will be reset to zero and the switching parameter will be adjusted. Or, set the time of day to start adjusting the switching parameters (e.g. 10:00 PM).

In another embodiment, as in step 307, it is determined whether the actual number of cutouts is greater than a threshold value of the number of cutouts. If so, step 305 is performed to start adjusting the switching parameters. The actual number of hand-outs here refers to the number of times the user equipment served by the source base station actually cuts out from the source base station to its neighbor base station. In an embodiment, the actual number of handouts represents the number of times that the neighboring base station has successfully configured the radio resource for the user equipment that triggered the handoff during the handout. Taking Figure 2 as an example, the source base station A_0 will record the number of times the user equipment serving it actually cuts out to the neighboring base station A_1, the number of times it actually cuts out to the neighboring base station A_2 ... In step 307, if the actual number of hand-off times of the source base station A_0 to a single neighboring base station is greater than a threshold value of the number of hand-out times, step 305 is performed to start adjusting handover parameters. The advantage of step 307 is that if the actual number of cutouts of the base station is large, it means that the base station has more information about the handover action, so more efficient handover parameter adjustment can be performed according to this information. Otherwise, the number of switching times is too small, and the information about the switching action will be relatively small. The switching parameters adjusted based on this information may be inaccurate.

FIG. 4 illustrates a flowchart of a method for adjusting a handover parameter according to an embodiment of the present invention, that is, step 305 in FIG. 3. As shown in FIG. 3, the method for adjusting a handover parameter according to an embodiment of the present invention includes the following steps:

Step 401

Calculate the cut-out success rate.

This step is to calculate the handoff success rate of the source base station within a period of time (for example, one hour). The cut-out success rate may be the overall cut-out success rate SA_0 of the source base station for all neighboring base stations, or the cut-out success rate of the source base station for each neighboring base station. For example, the source base station A_0 in FIG. 2 calculates the switching success rate SA_1 of the user equipment from the source base station A_0 to the neighboring base station A_1, and calculates the switching success rate of the user equipment from the source base station A_0 to the neighboring base station A_2. .

Step 403

Determine whether the number of cuts of the cutout success rate exceeds the critical number.

In this step, it is judged whether the overall cutout success rate SA_0 or the cutout success rate SA_1 or the cutout success rate SA_2 calculated in step 401 is compared with the cutout success rate calculated and recorded the previous time. If there is a drop, the number of drops is accumulated once.

The so-called decline here may mean that the overall success rate calculated in step 401 is less than the recorded overall cut-out success rate, or that the cut-out success rates with respective neighboring base stations are all smaller than the recorded cut-out success rate. For example, the newly calculated cut-out success rate SA_1 and cut-out success rate SA_2 are both smaller than the previously recorded cut-out success rate SA_1 and cut-out success rate SA_2. Alternatively, it can also mean that the partial cut-out success rate calculated in step 401 is less than the corresponding recorded cut-out success rate. For example, the calculated cut-out success rate SA_1 is greater than the recorded cut-out success rate SA_1, but the calculated cut-out success rate SA_2 is smaller than the recorded cut-out success rate SA_1.

In addition, step 403 determines whether the cumulative number of drops is greater than the critical number. If it is greater than the critical number, it proceeds to step 409. If it is less than the critical number, it proceeds to step 405. In one embodiment, the cut-out success rate calculated this time will be recorded instead of the originally recorded cut-out success rate. However, it is also possible to replace the originally recorded success rate after a certain period of time or after calculating the success rate of cutting out multiple times.

Step 405

Analyze the handover status from the source base station to each neighboring base station, for example, analyze the cut-out success rate calculated in step 401. This step will be described in detail in the subsequent description.

Step 407

Set the switching parameters based on the cutout success rate. In an embodiment, the handover parameter is positively related to the handoff success rate, that is, the source base station can give higher handover parameters to the neighboring base stations with a greater handoff success rate.

The handover parameter represents the trend of the handover action. Under the same conditions, the source base station can set the handover parameter corresponding to a specific neighboring base station to make the user equipment more or less tend to switch from the source base station to the Specific neighbor base stations. For example, in the second figure, the source base station A_0 can change the handover parameter corresponding to the neighboring base station A_1, so that the user equipment U_1 ... U_m tends to switch from the source base station A_0 to the neighboring base station A_1.

In one embodiment, the handover parameter is CIO (Cell Individual Offset, Cell Independent Offset). The higher the value, the higher the handover parameter. The detailed steps of how to change the trend of the switching action by changing the CIO will be detailed below.

After the switching parameters are set, subsequent cut-out actions will be performed according to the set switching parameters, until the switching parameter adjustment method is triggered again as shown in FIG. 3.

Step 409

Reset the switching parameters to the initial switching parameters. That is, if the number of times that the success rate decreases in the step 403 is greater than the critical number, the switching parameters are reset to the initial switching parameters. The advantage of this mechanism is that if steps 405 and 407 are continuously performed to adjust the handover parameters, but the success rate of the source base station to single or most neighboring base stations cannot be effectively improved, which means that the handover parameters at this time may deviate from the best. Switching parameters, and the switching parameters need to be reset to approach the best switching parameters again.

FIG. 5 shows a flowchart of the steps for analyzing the switching situation and setting the switching parameters in FIG. 4 of the present invention, that is, the detailed flowchart of steps 405 and 407.

As shown in Figure 5, step 405 includes:

Step 501

Filter out the success rate of the neighboring base stations whose actual cut-out times are less than the cut-off times critical value.

For example, if the cut-off frequency threshold is 20, and the actual cut-out times from the source base station A_0 to the neighboring base stations A_1 and A_2 in Figure 2 are greater than 20, respectively, the cut-out success rates of the neighboring base stations A_1 and A_2 are both It will be used as the basis for setting handover parameters. However, the actual number of handoffs from handover from source base station A_0 to neighboring base station A_3 is only 5. In this case, the success rate of handoff of neighboring base station A_3 will not be used to set handover parameters. in accordance with.

The advantage of this step is that if the actual number of cuts from the source base station A_0 to the neighboring base station A_3 is too small, the number of samples used to calculate the cutout success rate is too small, so the cutout success rate cannot represent the trueness of the neighboring base station A_3. State, and the associated impact on the accuracy of adjusting the switching parameters. Therefore, the success rate of the neighboring base stations with fewer actual cuts may not be used as a basis for setting handover parameters.

In an embodiment, the actual number of handoffs of the neighboring base stations whose actual number of handoffs is less than the threshold of the number of handoffs will not return to zero, but will be accumulated as the reference when the next handover parameter adjustment method is performed. However, the actual number of handoffs of the neighboring base stations whose actual number of handoffs is greater than the threshold of the number of handoffs will be reset to zero after this handover parameter adjustment method ends.

Step 503

Determine whether the number of neighboring base stations whose actual cut-out times are greater than the cut-off times threshold is 0 or 1? If yes, go to step 513 to end the handover parameter adjustment method. If not, go to step 505 to continue the method of switching parameter adjustment.

The reason for including this step is that if there are no neighboring base stations with actual handoff times greater than the cutout number threshold, it means that the handoff success rate of all neighboring base stations is not suitable as a basis for setting handover parameters, so the handover parameter adjustment method is ended. If the actual cut-out times of only one neighboring base station is greater than the cut-off times critical value, that is, the cut-out success rate of only one neighboring base station is suitable as a basis for setting handover parameters, then there is no base station to compare with this neighboring base station, and it is impossible to decide The higher handover parameter is set to that neighboring base station, so the handover parameter adjustment method is ended. Take Figure 2 as an example. If source base station A_0 can be switched to neighboring base station A_1 and neighboring base station A_2 in Figure 2, the actual cutout times of source base station A_0 to neighboring base station A_1 and neighboring base station A_2 are all greater than the cutout threshold. Value, the handover parameters of the source base station A_0 to the neighboring base station A_1 and the neighboring base station A_2 are set according to the cut-out success rate of the neighboring base station A_1 and the neighboring base station A_2.

Step 505

The cut-out success rate is hierarchically classified.

For example, if the cut-out success rate is 10%, the cut-out success rate of the neighboring base station A_1 relative to the source base station A_0 in Figure 2 is 91%, and the cut-off success rate of the neighboring base station A_2 relative to the source base station A_0. If the success rate is 85%, the cut-out success rate of the neighboring base station A_1 will be classified as level 1 and the cut-out success rate of the neighboring base station A_2 will be classified as level 2. In the same example, if the success rate of the neighboring base station A_1 with respect to the source base station A_0 is 71%, and the success rate of the neighboring base station A_2 with respect to the source base station A_0 is 79%, then the neighboring base stations A_1 and A_2 are switched out. Success rates are all classified as level 3. In this example, the smaller the level ordinal number, the higher the level. Please also note that the total number of levels and the success rate of cutouts covered by each level are not limited to this example.

The foregoing step 407 includes:

Step 507

Confirm whether the success rates of different neighboring base stations can correspond to different levels. If yes, go to step 511; otherwise, go to step 509.

Step 509

Adjust the handover parameter with the highest number of actual hand-out times in the neighboring base stations. For example, if the neighboring base station of the source base station A_0 in Figure 2 includes neighboring base stations A_1 and A_2, the neighboring base station A_1 has a larger number of actual cutouts than the neighboring base station A_2, and the neighboring base stations A_1 and A_2 are successfully cut out. The rates are classified to the same level in step 505, and the handover parameters of the neighboring base station A_1 relative to the base station A_0 will be increased.

The advantage of this step is that without this step, all neighboring base stations will be given the same handover parameters, so the difference in cut-out trends between the two neighboring base stations is not obvious. If a neighboring base station has a large number of actual handoffs, it indicates that the neighboring base station may have better performance, so more user equipment will switch to the neighboring base station, so higher handover parameters can be given.

Step 511

Set the handover parameters of the source base station to each neighboring base station according to the level of the cutout success rate corresponding to the neighboring base station.

In an embodiment, the foregoing hierarchy includes the highest hierarchy, the intermediate hierarchy, and the lowest hierarchy, that is, the cut-out success rates of all neighboring base stations are classified into the highest hierarchy, the intermediate hierarchy, and the lowest hierarchy. In step 511, the handover parameters of neighboring base stations with the highest success rate of hand-off are increased. In one embodiment, if the hand-off success rate of a neighboring base station is already 100%, the handover parameters are no longer adjusted. The advantage is that the condition of this neighboring base station has been optimized. If the handover parameters are increased, the user equipment will only be too concentrated in this neighboring base station, which may not help optimize the cutout success rate of all base stations. Step 511 will also reduce the handover parameters of the neighboring base stations with the lowest success rate of cut-out, and converge the handover parameters of the neighboring base stations with the success rate of cut-out of the middle hierarchy to the middle value, that is, make the source base station to a medium-level The handoff of neighboring base stations with a cut-out success rate tends to be neutral. For example, if the handover parameter is the aforementioned CIO, step 511 will increase the CIO of the neighboring base station with the highest cut-out success rate, reduce the CIO of the neighboring base station with the lowest cut-out success rate, and make the medium The CIOs of the neighboring base stations at the hierarchical cut-out success rate converge to zero. That is, if the CIO of a base station with a medium-level cut-out success rate is positive, its CIO is reduced, and if its CIO is negative, its CIO is increased to make its CIO converge to zero.

Taking Figure 2 as an example, if the neighboring base stations A_1, A_2, and A_3 have cut-out success rates SA_1, SA_2, and SA_3, respectively, and the cut-out success rates SA_1, SA_2, and SA_3 are classified as the highest level, the middle level, and the lowest level In step 511, the CIO of the neighboring base station A_1 is increased, the CIO of the neighboring base station A_3 is reduced, and the CIO of the neighboring base station A_2 is converged toward zero.

However, please note that the present invention is not limited to dividing the cut-out success rate into different levels. If there is no hierarchical level, step 5 does not include steps 505, 507, and 509, and step 511 directly depends on the source base station to each neighboring base station. Cut out the success rate to set handover parameters from the source base station to each neighboring base station.

According to the foregoing embodiment, the base station handover method provided by the present invention can be briefly shown in FIG. 6, which includes the following steps:

Step 601

Calculate the success rate of switching out from the source base station to different neighboring base stations. For example, steps 501-505 in Figure 5 of this case. Taking Figure 2 as an example, this step will calculate the cut-out success rates of the user equipment U_1 ... U_m from the source base station A_0 (source base station) to the neighboring base stations A_1 ... A_n.

Step 603

Set handover parameters of neighboring base stations according to the cut-out success rate. For example, steps 507-511 in Figure 5 of this case.

Step 605

Control the hand-off action from the source base station to the neighboring base station according to the handover parameter.

The foregoing steps 601-605 may be performed by the source base station, but may also be performed by an electronic device other than the source base station. For example, the source base station can provide information to other network management devices, and then let this network management device perform CIO settings for the source base station. As mentioned above, the handover parameter may be a CIO. The following will describe how to set the CIO to control the handover action of the user equipment. The following description uses RSRP (Reference Signal Receiving Power) to represent the signal strength.

Figures 7 and 8 show schematic diagrams of switching based on CIO and signal strength. As shown in FIG. 7, the user equipment U gradually leaves the coverage of the source base station A_0 that originally provided the service, and the signal strength of the source base station A_0 is weak. Therefore, the source base station A_0 controls the user equipment U to perform the cut-out action. In the example in FIG. 7, the neighboring base stations available for the user equipment U to cut out include base stations A_1-A_3. The basis for deciding which neighboring base station to switch to is usually the signal strength. In addition to the signal strength, other parameters can also be referred to, such as A3 offset, which defines that the neighboring base stations A_1-A_3 must be greater than the source base station A_0. How high is the signal strength to switch.

Taking Figure 8 as an example, if it is assumed that the signal strength of the source base station where the user equipment U is located is -90dbm and the offset of A3 is 10dbm, in this case, as long as the neighboring base stations A_1-A_3 can provide better than -80dbm The signal strength allows the user equipment to be switched over. Therefore, if the user equipment U is located at a neighboring base station A_1-A_3 that can receive -80dbm, the user equipment U may be handed over to any of the neighboring base stations A_1-A_3.

However, adjusting the CIO of the source base station to the neighboring base station may affect the tendency of user equipment handover. For example, in Figure 8, if the CIO given to the neighboring base station A_1 is 20dbm, as long as the neighboring base station A_1 can provide better or the same signal strength than -100dbm, the user equipment U can switch to the neighboring base station A_1, It is not necessary to wait until the user equipment U moves to a position where the neighboring base station A_1 can provide a signal strength of -80dbm, that is, the user equipment has a stronger tendency to switch to the base station A_1. Similarly, in Figure 8, if the CIO given to the neighboring base station A_2 is 15dbm, as long as the neighboring base station A_2 can provide better or the same signal strength than -95dbm, the user equipment U can switch to the neighboring base station A_2. It has to wait until the user equipment U moves to a location where the base station A_2 can provide -80dbm. In the example in FIG. 8, the CIO of the neighboring base station A_3 is set to zero, but because the A3 offset still needs to be met, the final switchable signal strength is still -80dbm. Therefore, by adjusting the CIO, the tendency of user equipment to switch base stations can be adjusted.

According to the foregoing embodiment, since the handover parameter of the source base station to the neighboring base station is adjusted according to the handoff success rate from the source base station to the neighboring base station, the user equipment is more likely to switch to the neighboring base station with a higher handoff success rate. Set better trigger conditions. And there is no need to transfer data through the connection between the base stations, so the handover action can be optimized without the connection between the base stations. The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the scope of patent application of the present invention shall fall within the scope of the present invention.

A_a, A_b‧‧‧Base Station

A_0‧‧‧source base station

A_1, A_2, A_3, A_n‧‧‧Neighboring base stations

U, U_1, U_2, U_m‧‧‧User equipment

FIG. 1 is a schematic diagram of a user equipment performing handover between base stations in the prior art. FIG. 2 is a schematic diagram showing that multiple user equipments are cut out from a source base station to multiple neighboring base stations. FIG. 3 is a schematic flowchart of a method for triggering a handover parameter adjustment according to an embodiment of the present invention. FIG. 4 is a flowchart illustrating steps of a method for adjusting a handover parameter according to an embodiment of the present invention. FIG. 5 illustrates a flowchart of the steps of analyzing the cut-out condition and setting the switching parameters in FIG. 4 according to an embodiment of the present invention. FIG. 6 shows a simplified flowchart of a method for adjusting a handover parameter according to an embodiment of the present invention. Figures 7 and 8 show schematics of cutting out based on the CIO and signal strength.

Claims (9)

A method for adjusting a handover parameter of a base station includes: (a) calculating a handout success rate of a plurality of neighboring base stations cut out by a source base station to the source base station; (b) classifying the plurality of handout success rates hierarchically, and Set the handover parameters of the multiple neighboring base stations according to the multiple levels; and (c) control the switching out action from the source base station to the multiple neighboring base stations according to the multiple handover parameters; wherein the multiple handover parameters affect the The source base station cuts out the trend to the multiple neighboring base stations. The method for adjusting a handover parameter of a base station according to claim 1, further comprising: calculating an actual number of cutouts actually cut out from the source base station to at least one of the plurality of neighboring base stations; and when a sum of the actual number of cutouts is greater than Perform steps (a), (b), and (c) only when the cutout number is critical. The method for adjusting a base station handover parameter according to claim 1, further comprising: before performing step (b), determining whether at least one of the plurality of cut-out success rates is less than a recorded cut-out success rate, and accumulating the plurality of cut-out success rates. At least one of the cut-out success rates is less than the recorded number of drops of the cut-out success rate; if the number of drops is less than the critical number, then step (b) is performed to set the plurality of switching parameters, and when the number of drops is greater than the A critical number of times, reset the multiple switching parameters to the initial switching parameters. The method for adjusting a handover parameter of a base station according to claim 1, further comprising: calculating an actual number of hand-outs from the source base station to the multiple neighboring base stations; the corresponding actual number of hand-outs is greater than a cut-off number threshold Only the handoff success rate of the neighboring base station will be used to calculate handover parameters; and the corresponding handoff success rate of the neighboring base station whose actual handoff times are less than the threshold of the handoff times will not be used Calculate the switching parameters. The method for adjusting a handover parameter of a base station according to claim 1, further comprising: calculating an actual number of hand-outs from the source base station to the multiple neighboring base stations; the corresponding actual number of hand-outs is greater than a cut-off number threshold Only when the number of the plurality of neighboring base stations is not less than two, step (b) and step (c) are performed. The method for adjusting a base station handover parameter according to claim 1, wherein the multiple levels include a highest level, a middle level, and a lowest level; the step (b) further includes: adding the neighbor having the cutout success rate of the highest level The handover parameter of the base station; reducing the handover parameter of the neighboring base station having the cut-out success rate of the lowest level; and converging the handover parameter of the neighboring base station with the cut-out success rate of the middle level toward an intermediate value . According to the base station handover parameter adjustment method described in claim 1, the step (b) further includes: if all neighboring base stations have the same level, adding a maximum actual cut out of the multiple neighboring base stations having the same level The number of times the handover parameter of the neighboring base station. According to the method for adjusting a handover parameter of a base station according to claim 1, the plurality of handover parameters is positively related to the plurality of cut-out success rates. The base station handover parameter adjustment method according to claim 1, wherein the plurality of handover parameters are independent offsets of the source base station to the cells of the neighboring base stations.