A method, device and equipment for compensating for a failed cell coverage area

Abstract

The present invention discloses a method, device and equipment for compensating the coverage area of ​​a failed cell. The method comprises: when a first cell is detected to be failed, obtaining data required for compensating the coverage area after the failure of the first cell; obtaining at least one second cell for compensating the coverage area of ​​the first cell according to the data; adjusting the parameters of the at least one second cell to obtain the adjusted antenna weight of the at least one second cell; and compensating the failed coverage range of the first cell according to the coverage range under the adjusted antenna weight of the at least one second cell. In the above manner, the present invention realizes fine and rapid coverage of the cell coverage area of ​​the failed site.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a method, device and equipment for compensating a failed cell coverage area. Background Art

[0002] In existing network applications, due to various situations, such as power outages, rain and snow storms, damage outside municipal construction, base station equipment software upgrades or software configuration errors, base stations or cells often fail. For example, the failure time caused by base station equipment software upgrades or software configuration errors is short and can be restored in a short time (within one day); while other site failures caused by hardware factors often require a certain amount of time for emergency repairs (about one week). During this period, communication guarantee vehicles and other means are usually used to compensate for the coverage area of ​​the failed site. Whether it is a short-term site failure (within one day) or a long-term site failure that requires coverage restoration using communication guarantee, it takes a certain amount of time, which will bring a less friendly network experience to existing network users and there will be a risk of user complaints. Specifically, when using a communication guarantee vehicle to supplement coverage of a failed site, the operator needs to drive the vehicle to the coverage hole area of ​​the failed site, and after manual judgment, adjust the communication guarantee vehicle to the coverage failure area. This method not only has a slow response, but also requires high costs (vehicle costs, personnel costs), and due to the manual judgment and adjustment method, the compensation effect is not necessarily reliable. This makes achieving rapid coverage compensation for failed sites a very valuable practical issue.

[0003] In 4 / 5G networks, the Massive MIMO (massive multiple input multiple output) antennas used have beamforming capabilities, so they have strong wireless signal coverage capabilities. Furthermore, considering the propagation loss and penetration loss of high-frequency shortwave used by 4 / 5G, as well as the guarantee of good coverage and capacity for users, when actually building a network, the distance between sites is usually much smaller than the actual coverage range of the site. This provides a theoretical guarantee for quickly compensating for failed site coverage by adjusting the Massive MIMO antenna.

[0004] The existing failed site coverage compensation method has low timeliness, poor coverage recovery effect, and high cost. Summary of the invention

[0005] In view of the above problems, embodiments of the present invention are proposed to provide a method, device and apparatus for compensating for a failed cell coverage area that overcomes the above problems or at least partially solves the above problems.

[0006] According to one aspect of an embodiment of the present invention, a method for compensating a failed cell coverage area is provided, the method comprising:

[0007] When a failure of the first cell is detected, acquiring data required for compensation of the coverage area after the failure of the first cell;

[0008] Obtaining, according to the data, at least one second cell for compensating for the coverage area of ​​the first cell;

[0009] Adjusting parameters of the at least one second cell to obtain adjusted antenna weights of the at least one second cell;

[0010] The failed coverage of the first cell is compensated according to the coverage of the at least one second cell under the adjusted antenna weight.

[0011] According to another aspect of an embodiment of the present invention, a compensation device for a failed cell coverage area is provided, the device comprising:

[0012] A first acquisition module is used to acquire data required for coverage area compensation after failure of the first cell when failure of the first cell is detected;

[0013] A second acquisition module, configured to obtain, according to the data, at least one second cell for compensating for the coverage area of ​​the first cell;

[0014] An adjustment module, configured to adjust the parameters of the at least one second cell to obtain an adjusted antenna weight of the at least one second cell;

[0015] The compensation module is used to compensate for the failed coverage of the first cell according to the coverage of the at least one second cell under the adjusted antenna weight.

[0016] According to another aspect of an embodiment of the present invention, there is provided a computing device, comprising: a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus;

[0017] The memory is used to store at least one executable instruction, and the executable instruction enables the processor to execute operations corresponding to the above-mentioned compensation method for the failed cell coverage area.

[0018] According to another aspect of the embodiments of the present invention, a computer storage medium is provided, wherein at least one executable instruction is stored in the storage medium, and the executable instruction enables a processor to execute operations corresponding to the above-mentioned method for compensating a failed cell coverage area.

[0019] According to the solution provided by the above embodiment of the present invention, when the failure of the first cell is detected, the data required for compensating the coverage area after the failure of the first cell is obtained; based on the data, at least one second cell for compensating the coverage area of ​​the first cell is obtained; the parameters of the at least one second cell are adjusted to obtain the adjusted antenna weight of the at least one second cell; based on the coverage range under the adjusted antenna weight of the at least one second cell, the failed coverage range of the first cell is compensated. By adjusting the antenna weight of the second cell adjacent to the first cell, fine and rapid coverage of the cell coverage area of ​​the failed site is achieved.

[0020] The above description is only an overview of the technical solution of the embodiment of the present invention. In order to more clearly understand the technical means of the embodiment of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present invention more obvious and easy to understand, the specific implementation method of the embodiment of the present invention is specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the embodiments of the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0022] Figure 1 A flow chart of a method for compensating a failed cell coverage area provided by an embodiment of the present invention is shown;

[0023] Figure 2 A flow chart showing a method for adjusting antenna weights of a second cell in a method for compensating for a failed cell coverage area provided by another embodiment of the present invention;

[0024] Figure 3 A schematic diagram of radially covering key points in an embodiment of the present invention is shown;

[0025] Figure 4 A schematic diagram showing the respective coverage areas and reference positions of the failed first cell P and the coverage compensation second cell Q of the present invention;

[0026] Figure 5 A schematic diagram showing the calculation of the approximate optimal electronic downtilt angle of the second cell Q of the present invention is shown;

[0027] Figure 6 A schematic diagram showing the calculation of the electron direction angle and horizontal wave width of the second cell Q according to the respective coverage areas of the failed first cell P is shown;

[0028] Figure 7A flow chart of a method for compensating a failed cell coverage area provided by a specific embodiment of the present invention is shown;

[0029] Figure 8 A schematic diagram showing the structure of a compensation device for a failed cell coverage area provided by an embodiment of the present invention is shown;

[0030] Fig. 9 A schematic diagram of the structure of a computing device provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0031] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0032] Figure 1 FIG. 2 is a flow chart showing a method for compensating a failed cell coverage area provided by an embodiment of the present invention. Figure 1 As shown, the method comprises the following steps:

[0033] Step 11, when the failure of the first cell is detected, the data required for the coverage area compensation after the failure of the first cell is obtained; here, it can be determined whether the first cell is a cell of the failed site through the failure alarm data; when the failure of the first cell is detected, the working parameter data of the failed site and the working parameter data of the neighboring cells of the failed cell included in the failed site can be obtained, and the working parameter data here can include CGI (global cell identification code), cell name, longitude and latitude, hanging height, mechanical downtilt angle, direction angle, equipment type, network type and other information; further, the beam parameters of the failed site and the beam parameters of the neighboring cells of the failed cell included in the failed site can also be obtained, and the beam parameters include one or more of CGI and cell name, weight scenario type, direction angle and downtilt angle, and sub-beam level data; further, the neighboring area list of the failed site can also be obtained, that is, the neighboring area list of each failed cell; here, when obtaining the data required for the coverage area compensation after the failure of the first cell, the relevant data required for the above-mentioned coverage compensation can be obtained from the relevant data center;

[0034] Step 12: obtaining, based on the data, at least one second cell for compensating for the coverage area of ​​the first cell; wherein the at least one second cell forms a neighboring cell set with adjustable weights;

[0035] Step 13: Adjust the parameters of the at least one second cell to obtain the adjusted antenna weight of the at least one second cell;

[0036] Step 14: Compensate for the failed coverage of the first cell according to the coverage of the at least one second cell under the adjusted antenna weights.

[0037] In this embodiment, when the failure of the first cell is detected, data required for compensation of the coverage area after the failure of the first cell is obtained; according to the data, at least one second cell for compensating the coverage area of ​​the first cell is obtained; the parameters of the at least one second cell are adjusted to obtain the adjusted antenna weight of the at least one second cell; and according to the coverage under the adjusted antenna weight of the at least one second cell, the failed coverage range of the first cell is compensated. Fine and rapid coverage of the cell coverage area of ​​the failed site is achieved.

[0038] In an optional embodiment of the present invention, step 12 may include:

[0039] Step 121, in the coverage area of ​​the first cell, obtaining a cell whose RSRP signal strength is greater than a first preset value as a candidate cell;

[0040] Step 122: Screen the candidate cells to obtain at least one second cell for compensating the coverage area of ​​the first cell. Specifically, remove the co-site neighboring cells of the first cell and the cells that do not include the first cell from the candidate cells to obtain at least one second cell for compensating the coverage area of ​​the first cell.

[0041] In this embodiment, step 121 may include, when implemented specifically:

[0042] Step 1211, select all cells with RSRP signal strength greater than -95dbm within the original weight coverage of the failed cell i as candidate cells to form a set Cell i ;

[0043] Step 1212, from the collection Cell i Remove the same-station neighboring cells of the cell;

[0044] Step 1213, according to the set Cell i The mechanical direction angle of each cell in is the normal line. Within the range of 120°, draw a sector with a radial distance of 600 meters (configurable) to determine whether it contains the failed cell i, and select the sector from the set Cell i Remove all cells that do not contain the failed cell i;

[0045] Step 1214: if a site fails at this time, multiple cells will be included. If one of the weight-adjustable neighboring cells belongs to multiple failed cells at the same time after the above calculation, the nearest failed cell is selected as its candidate cell.

[0046] Step 1215: for each failed cell i, output a candidate cell set Cell with adjustable weights i .

[0047] In an optional embodiment of the present invention, step 13 may include:

[0048] Step 131, obtaining at least one first key point within the coverage area of ​​the first cell; the first key point here can be the vertical upper and lower 3db lobe coverage points, horizontal left and right 3db lobe coverage points, etc. of the weight of the first cell;

[0049] Step 132, obtaining a radial distance range and a north deflection angle between the at least one first key point and the coverage area of ​​the at least one second cell;

[0050] Here, obtaining the radial distance range between the at least one first key point and the coverage area of ​​the at least one second cell includes:

[0051] Step 1321, obtaining a distance between the at least one first key point and at least one second key point in the coverage area of ​​the at least one second cell;

[0052] Step 1322, obtaining a radial distance range according to the distance.

[0053] Here, obtaining the north deflection angle of the coverage area of ​​the at least one first key point and the at least one second cell includes:

[0054] A second key point in the second cell is obtained, and a north deflection angle between the first key point and the second key point is calculated.

[0055] Step 133, calculating the adjusted antenna weights of the at least one second cell according to the radial distance range and the north deflection angle, the antenna weights including at least one of: electronic downtilt angle, vertical beam width, horizontal beam width, and electronic direction angle.

[0056] In the specific implementation of this embodiment, if the weight of the failed cell i is adjustable, the candidate cell set Cell i If it is not empty, the original coverage area of ​​the failed cell can be quickly optimized, such as Figure 2 As shown, the process includes:

[0057] 21: For the failed cell P, calculate the relative distance of its coverage key points (O, B, F, L, R), where B and F are the vertical upper and lower 3db lobe coverage points of the original weight of the failed cell P, and L and R are the horizontal left and right 3db lobe coverage points. Specifically, Figure 3 As shown, tilt and etilt are the mechanical downtilt angle and electronic downtilt angle of the failed cell P respectively, so the total downtilt is V θ =tilt+etilt, H is the height of the cell, vhw is the vertical wave width, then the distances of O, B, and F relative to point P are calculated as:

[0058]

[0059]

[0060]

[0061] 22: Calculate the absolute position (i.e., longitude and latitude values) of the key points (O, B, F, L, R) in the coverage range of the failed cell P. Specifically, Figure 4 As shown, azimuth and eazimuth are the mechanical and electronic azimuth of the failed cell P, respectively, and bhw is the horizontal wave width. The total azimuth is H θ =azimuth+eazimuth, then we have

[0062] O x =P x +PO*|sin(H θ )|,O y =P y +PO*|cos(H θ )|; (4)

[0063] B x =P x +PB*|sin(H θ )|,B y =P y +PB*|cos(H θ )|; (5)

[0064] F x =P x +PF*|sin(H θ )|,F y =P y +PF*|cos(H θ )|; (6)

[0065] L x =P x +PL*|sin(H θ-0.5*bhw)|,

[0066] L y =P y +PL*|cos(H θ -0.5*bhw)|; (7)

[0067] R x =P x +PR*|sin(H θ +0.5*bhw)|,

[0068] R y =P y +PR*|cos(H θ +0.5*bhw)|; (8)

[0069] Similarly, for the N cells in the neighboring cell set of the failed cell P, select the top three cells with the largest RSPR values ​​in the failed cell P, and analyze the key points (O i ,B i ,F i ,L i ,R i ) absolute position (i∈{1,…,3} represents the Qth i Neighboring cells) are calculated, and only the neighboring cells with the strongest signal are considered, and a maximum of 3 are considered, so that the effectiveness of compensation and the impact on the existing network can be taken into account at the same time. i , the weight scheme is calculated through the following steps.

[0070] 23: According to the distance Q i O and Q i B i , we can approximate the radial range of the main coverage area at this time,

[0071] dist pi =Q i OQ i B i (9)

[0072] like Figure 5 As shown, the value of the electronic downtilt angle required for actual compensation is calculated

[0073]

[0074] where tilt i Neighboring cell Q i Mechanical down-tilt angle, H i To stand tall, etilt i To find the electronic down-tilt angle;

[0075] 24: Further, the vertical beam width required for actual compensation is

[0076]

[0077] in Indicates neighboring cell Q i The original electron down-tilt angle;

[0078] 25: Calculate compensation cell Q i The north deflection angle (i.e., horizontal direction angle) of the key points (O, B, F, L, R) in the coverage range of the failed cell P is as follows: Figure 6 As shown,

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085] where azimuth i , They are neighboring cell Q i The mechanical direction angle, the original electronic direction angle, and the original horizontal wave width. Select the maximum value θ max and the minimum value θ min , then the horizontal wave width is hbw i =θ max -θ min (18)

[0086] Similarly, the electron direction angle is

[0087]

[0088] 26: Get the actual weight scheme. According to the default weight pattern of the corresponding manufacturer and the corresponding network standard, such as the default weight table of manufacturer A 5G shown in Table 1, select the calculated theoretical vertical beam width vbw i 、Horizontal wave width hbw i The closest wave width value and if and If the value is increased by 3-4 gears compared to the original value, SSBboosting will be increased by 3db; if the value is increased by more than 4 gears, SSBboosting will be increased by 6db; the electronic direction angle is taken as eazimuth i The closest value Similarly, the electronic downtilt angle is taken as etilt i The closest value

[0089] Table 1A Manufacturer 5G default weight table

[0090]

[0091] In an optional embodiment of the present invention, step 14 may include:

[0092] Step 141: Obtain an average value of the first reference signal received power RSRP of the first coverage sector within the coverage area of ​​the first cell. and an average value of a second reference signal received power RSRP of a second coverage sector within the coverage area of ​​the second cell

[0093] Step 142: according to the average value of the second RSRP Obtaining a coverage quality assessment value of a second coverage sector within the coverage area of ​​the second cell

[0094] Step 143: based on the coverage quality evaluation value of the second coverage sector Obtaining a signal coverage quality assessment value of a first coverage sector within the coverage area of ​​the first cell

[0095] Step 144: based on the coverage quality evaluation value of the second coverage sector The average value of the second RSRP of the second coverage sector The first difference and the first preset threshold, and the signal coverage quality evaluation value of the first coverage sector The average value of the first RSRP of the first coverage sector The difference between the first cell and the second preset threshold is used to compensate for the failed coverage of the first cell.

[0096] In the specific implementation of this embodiment, for each coverage compensation cell Q of each failed cell P i (i≤3) all get a set of coverage compensation weight combinations

[0097] For each failed cell P, a coverage sector S can be determined based on its original weighted horizontal beam width, electronic direction angle, and upper 3db vertical beam width, combined with the mechanical direction angle and mechanical downtilt angle. P , the sector S P After gridding, the average RSRP can be evaluated using the simulation model.

[0098] Specifically, for the sector S P All grids covered are, and the RSRP value on each grid k is calculated for the original weight combination In the S P The corresponding grid numbers are averaged.

[0099]

[0100] Where count(grid) means calculating S P The raster data in That is, the average RSRP value of the original weight of the failed cell P evaluated through simulation within the coverage area.

[0101] Similarly, for each compensation cell Q i , we can also get the coverage fan of its original weight And the RSRP value on each grid k Then calculate the average RSRP value in the fan-shaped area according to formula (20):

[0102] In addition, for the compensation cell Q i , for each set of cover compensation weight combination The same process is used to calculate its fan The coverage quality assessment value For each coverage compensation cell Q i (i≤3) Through the compensation weight calculated by itself, the coverage grid of the failed cell P (corresponding S P The RSRP value in the sector

[0103]

[0104] That is, select the largest value in each grid k As the RSRP value obtained by compensation for the grid, the result obtained by formula (21) is then substituted into formula (20) to obtain the signal coverage in the coverage area of ​​the failed cell P at this time.

[0105] The action set of the designed coverage optimization intelligent control algorithm is shown in the following table:

[0106] Table 2 Coverage optimization intelligent control action table

[0107]

[0108] The specific values ​​of the actions involved are determined according to the default weight table of the specific equipment of the specific network standard of the specific manufacturer (as shown in Table 1 above).

[0109] In an optional embodiment of the present invention, the above-mentioned method for compensating the outage cell coverage area may further include:

[0110] During the failure of the first cell, if the number of signal quality warnings of the first cell received is greater than X times, the parameters of at least one second cell are adjusted again, and the failed coverage range of the first cell is compensated according to the coverage range under the antenna weight after the at least one second cell is adjusted again; or

[0111] During the failure of the first cell, if the number of signal quality warnings received from the second cell is greater than Y times, the second cell is removed from the neighboring cell set consisting of at least one second cell to obtain an updated neighboring cell set. If the number of second cells with adjustable weights in the updated neighboring cell set is not zero, compensation for the failed coverage of the first cell is performed again; if the number of second cells with adjustable weights in the updated neighboring cell set is zero, an alarm is output that the first cell cannot be compensated through weight adjustment.

[0112] Combine the following Figure 7 The specific process shown illustrates the implementation process of the above method:

[0113] 71: record all failed cells P as unvisited;

[0114] 72: Randomly select an unvisited failed cell P (i.e., the first cell mentioned above) and its coverage compensation cell set {Q i}, that is, a set consisting of the at least one second cell;

[0115] 72.1: Calculation Each compensation area as well as

[0116] 72.2: Calculation For each compensation cell, calculate

[0117] 72.3: If

[0118] Among them, 72.2.1: That is, all compensation cells Q i Satisfy own coverage or partially compensate for cell Q i When the self-coverage is satisfied, for all the compensation cells that meet the conditions, it means that the currently calculated compensation weight can guarantee its basic coverage. Sort the values ​​from large to small and enter the following for loop;

[0119] 72.2.1.2: fori = 1, for the current cell Q i ,

[0120] 72.2.1.2.1: If the electronic downtilt angle is adjustable, perform a positive action (raise 1°) on the electronic downtilt angle and recalculate after each action.

[0121] 72.2.1.2.1.1: Community Q i Still meets coverage;

[0122] 72.2.1.2.1.1.1: This indicates that the optimization of the failed cell P is completed, and the process returns to step 72 to calculate the next failed cell;

[0123] 72.2.1.2.1.1.2: Then jump back to 72.2.1.2.1 to continue adjustment and calculation;

[0124] 72.2.1.2.1.1.3: else, description Degenerates compared to the previous step, ends the loop of 72.2.1.2 (i.e. proceeds to the subsequent steps), and falls back to the value of the previous step;

[0125] 72.2.1.2.1.2: else, cell Q i The coverage is no longer satisfied, so the loop of 72.2.1.2 ends (i.e., proceeds to the subsequent steps) and returns to the value of the previous step;

[0126] 72.2.1.2.2: If the electronic direction angle is adjustable, perform a positive action (adjust 3° clockwise) on the electronic direction angle, and recalculate after each action. Repeat the logical steps of 72.2.1.2.1.1-72.2.1.2.1.2 to complete the traversal of the electronic direction angle;

[0127] 72.2.1.2.3: If the horizontal beam width is adjustable, perform a positive action on the horizontal beam width (expand one level) and recalculate Repeat the logical steps of 72.2.1.2.1.1-72.2.1.2.1.2. If 72.2.1.2.1.1.2 takes effect, jump back to 72.2.1.2.1-72.2.1.2.2 to traverse and optimize the electronic downtilt angle and electronic direction angle under the current horizontal beam width;

[0128] 72.2.1.2.4: If the vertical beam width is adjustable, perform a positive action on the vertical beam width (expand one level) and recalculate Repeat the logical steps of 72.2.1.2.1.1-72.2.1.2.1.2. If 72.2.1.2.1.1.2 takes effect, jump back to 72.2.1.2.1-72.2.1.2.2 to traverse and optimize the electronic downtilt angle and electronic direction angle under the current vertical beam width;

[0129] 72.2.1.2.5: If the current horizontal and vertical bandwidths are not adjustable, jump back to 72.2.1.2 and adjust the Q of the next cell. i Perform optimization calculations;

[0130] 72.2.1.3: Complete all compensation cells Q that meet their own coverage i After optimization, for the compensation cell Q that does not meet its own coverage i and the failed cell P,

[0131] 72.2.1.3.1: And all cells that do not meet their own coverage requirements Q i have This indicates that the current compensation weight can meet the minimum wireless coverage standard, so the weight is output and the process returns to step 72 to perform the next failed site optimization.

[0132] 72.2.1.3.2: else, output an alarm for the current failed site, indicating that "weight optimization cannot be used for coverage compensation";

[0133] 72.4: else, indicating that the coverage of the failed site P has been satisfied;

[0134] 72.4.1: For all compensation cells Q i , and also meets its own coverage conditions, then jump back to 72 to calculate the next failed cell;

[0135] 72.4.2: else, optimize each cell that does not meet its own coverage conditions;

[0136] 72.4.2.1: fori = 1, for the current cell Q i ,

[0137] 72.4.2.1.1: If the electronic downtilt angle is adjustable, perform negative actions (press down 1°) on the electronic downtilt angle and recalculate after each action.

[0138] 72.4.2.1.1.1: The failed cell P still meets the coverage requirements;

[0139] 72.4.2.1.1.1.1: This means that the current cell Q i Optimization completed, jump back to 72.4.2.1 for the next compensation cell Q i Perform calculations;

[0140] 72.4.2.1.1.1.2: Then jump back to 72.4.2.1.1 to continue adjustment and calculation;

[0141] 72.4.2.1.1.1.3: else, description It has degenerated compared to the previous step, ending the loop of 72.4.2.1.1 (i.e., proceeding to the subsequent steps) and reverting to the value of the previous step;

[0142] 72.4.2.1.1.2: else, the failed cell P no longer meets the coverage requirements, the loop of 72.4.2.1.1 is terminated (i.e., the subsequent steps are performed), and the value of the previous step is returned;

[0143] 72.4.2.1.2: If the electronic direction angle is adjustable, perform a negative action (adjust 3° counterclockwise) on the electronic direction angle, and recalculate after each action. Repeat the logical steps of 72.4.2.1.1.1-72.4.2.1.1.2 to complete the traversal of the electronic direction angle;

[0144] 72.4.2.1.3: If the horizontal beam width is adjustable, perform a negative action on the horizontal beam width (shrink one level) and recalculate Repeat the logical steps of 72.4.2.1.1.1-72.4.2.1.1.2. If 72.4.2.1.1.1.2 is effective, jump back to 72.4.2.1.1-72.4.2.1.2 to traverse and optimize the electronic downtilt angle and electronic direction angle under the current horizontal beam width;

[0145] 72.4.2.1.4: If the vertical beam width is adjustable, perform a negative action on the vertical beam width (reduce it by one level) and recalculate Repeat the logical steps of 72.4.2.1.1.1-72.4.2.1.1.2. If 72.3.2.1.1.1.2 is effective, jump back to 72.4.2.1.1-72.4.2.1.2 to traverse and optimize the electronic downtilt angle and electronic direction angle under the current vertical beam width;

[0146] 72.4.2.1.5: Compensation cell Q i The calculated optimal

[0147] 72.4.2.1.5.1: Then jump back to 72.4.2.1, for the next cell Q i Perform optimization calculations. If all compensation cells meet the minimum wireless coverage standard, output weights and jump back to step 72 to optimize the next failed site.

[0148] 72.4.2.1.5.2: else, output an alarm for the current failed site, prompting "Unable to use weight optimization method for coverage compensation", and jump back to 72 to optimize the next failed site;

[0149] 73: When all failed cells P are marked as visited, the weight scheme or alarm of the compensation cell (or compensation cell set) of each failed cell P is output (i.e., it is prompted that "the weight optimization method cannot be used for coverage compensation")

[0150] where Δ p and Δ Q The expected change in the wireless signal quality of the failed cell after compensation and the compensated cell compared with the original weight, in db. For example, the signal strength of site P before failure is If we hope that the signal quality after compensation remains half of the original, then Δ p =3db, that is, after compensation Or, if the expected signal strength after compensation is 80% of the original, then Δ p =10log 1.25=0.97dbm.

[0151] The method described in this embodiment can simultaneously consider the absolute values ​​of the signals of the failed site and the compensation site, and make personalized considerations for the degree of signal recovery of the failed site and the degree of signal decay of the compensation site compared with the previous one when calculating the compensation coverage of the failed site, so as to complete the rapid optimization of the failed coverage on the basis of ensuring the information quality of the failed site and the compensation site. In addition, in order to improve the calculation efficiency (that is, to achieve coverage through weight adjustment as much as possible) and consider the actual availability and rationality, the threshold of -95dbm, which is an acceptable threshold for wireless signal coverage, is designed in the intelligent control algorithm as the judgment threshold in the algorithm, thereby improving the probability of the algorithm calculating a valid weight solution, improving the algorithm efficiency and actual availability. Note that in order to further improve the calculation efficiency of the intelligent control algorithm, in some cases, if the wireless signal quality assurance thresholds threshold_s and threshold_n of the failed cell and the compensation cell are directly set to -95dbm, according to the design of the algorithm itself, some of the intermediate logical calculation processes will be simplified, which improves the flexibility of the algorithm, and further improves the calculation efficiency of the algorithm and the probability of outputting the solution.

[0152] Assume that the neighboring cells of the failed site cell can finally output the weight adjustment plan W. After being executed in the existing network for a period of time, if the failed cell area receives more than X (default X=2, configurable) signal quality complaints, the adjustment plan W is used as the initial value, the intelligent control algorithm is restarted, and the failed cell coverage is optimized again, and a plan that meets the coverage conditions and is different from the adjustment plan W is output; if no other plan can be found except the adjustment plan W, an alarm is output, indicating that "the weight optimization method cannot be used for coverage compensation."

[0153] Of course, during the period of failure of the first cell, if the number of signal quality warnings received from the second cell is greater than Y times, the second cell will be removed from the neighboring cell set consisting of at least one second cell to obtain an updated neighboring cell set. If the number of second cells with adjustable weights in the updated neighboring cell set is not zero, compensation for the failed coverage range of the first cell will be performed again; if the number of second cells with adjustable weights in the updated neighboring cell set is zero, an alarm will be output that the first cell cannot be compensated through weight adjustment.

[0154] In the above-mentioned embodiment of the present invention, by screening the adjacent cells of the failed site, the adjacent cells with adjustable weights can be automatically and quickly located as an adjustment template for the coverage compensation of the failed site, eliminating the manual screening process; the coverage compensation method can quickly calculate the coverage compensation scheme achieved by adjusting the neighboring cell weights, which is highly efficient and reasonable; the coverage compensation target (hyperparameter configuration) can be set according to the existing network conditions, and the minimum coverage standard of the wireless network can be taken into account, so as to achieve rapid and effective optimization of the coverage compensation initialization scheme, and eliminate the manual existing network test environment, thereby reducing labor costs; at the same time, it can also be compatible with different manufacturers and different network standards (4 / 5G), so it can be greatly used in the complex and changeable scenarios of the existing network, with a high degree of flexibility, highlighting the usability of this patent.

[0155] Figure 8 FIG. 2 is a schematic diagram showing the structure of a compensation device for a failed cell coverage area provided by an embodiment of the present invention. Figure 8 As shown, the device comprises:

[0156] A first acquisition module 81 is used to acquire data required for coverage area compensation after failure of the first cell when failure of the first cell is detected;

[0157] A second acquisition module 82, configured to obtain, according to the data, at least one second cell for compensating for the coverage area of ​​the first cell;

[0158] An adjustment module 83, configured to adjust the parameters of the at least one second cell to obtain an adjusted antenna weight of the at least one second cell;

[0159] The compensation module 84 is used to compensate for the failed coverage of the first cell according to the coverage of the at least one second cell under the adjusted antenna weight.

[0160] Optionally, obtaining, according to the data, at least one second cell for compensating for the coverage area of ​​the first cell includes:

[0161] In the coverage area of ​​the first cell, a cell having a reference signal received power RSRP signal strength greater than a first preset value is obtained as a candidate cell;

[0162] The candidate cells are screened to obtain at least one second cell for compensating for the coverage area of ​​the first cell.

[0163] Optionally, screening the candidate cells to obtain at least one second cell for compensating for the coverage area of ​​the first cell includes:

[0164] At least one second cell for compensating the coverage area of ​​the first cell is obtained by removing the co-site neighboring cells of the first cell and the cells not including the first cell from the candidate cells.

[0165] Optionally, adjusting the parameters of the at least one second cell to obtain the adjusted antenna weight of the at least one second cell includes:

[0166] Obtaining at least one first key point within the coverage area of ​​the first cell;

[0167] Obtaining a radial distance range and a north deflection angle between the at least one first key point and a coverage area of ​​the at least one second cell;

[0168] According to the radial distance range and the north deflection angle, the adjusted antenna weights of the at least one second cell are calculated, and the antenna weights include: at least one of: electronic downtilt angle, vertical beam width, horizontal beam width, and electronic direction angle.

[0169] Optionally, obtaining a radial distance range between the at least one first key point and a coverage area of ​​the at least one second cell includes:

[0170] Obtaining a distance between the at least one first key point and at least one second key point within the coverage area of ​​the at least one second cell;

[0171] According to the distance, a radial distance range is obtained.

[0172] Optionally, compensating for the failed coverage of the first cell according to the coverage of the at least one second cell under the adjusted antenna weights includes:

[0173] Obtain an average value of the first reference signal received power RSRP of the first coverage sector within the coverage range of the first cell and an average value of a second reference signal received power RSRP of a second coverage sector within the coverage area of ​​the second cell

[0174] According to the average value of the second RSRP Obtaining a coverage quality assessment value of a second coverage sector within the coverage area of ​​the second cell

[0175] According to the coverage quality evaluation value of the second coverage sector Obtaining a signal coverage quality assessment value of a first coverage sector within the coverage area of ​​the first cell

[0176] According to the coverage quality evaluation value of the second coverage sector The average value of the second RSRP of the second coverage sector The first difference and the first preset threshold, and the signal coverage quality evaluation value of the first coverage sector The average value of the first RSRP of the first coverage sector The difference between the first cell and the second preset threshold is used to compensate for the failed coverage of the first cell.

[0177] Optionally, the processing module 84 is further configured to, during the failure of the first cell, if the number of times the signal quality warning of the first cell is received is greater than X times, adjust the parameters of at least one second cell again, and compensate for the failure coverage of the first cell according to the coverage under the antenna weight after the at least one second cell is adjusted again; or

[0178] During the failure of the first cell, if the number of signal quality warnings received from the second cell is greater than Y times, the second cell is removed from the neighboring cell set consisting of at least one second cell to obtain an updated neighboring cell set. If the number of second cells with adjustable weights in the updated neighboring cell set is not zero, compensation for the failed coverage of the first cell is performed again; if the number of second cells with adjustable weights in the updated neighboring cell set is zero, an alarm is output that the first cell cannot be compensated through weight adjustment.

[0179] It should be noted that the device is a device corresponding to the above method, and all implementation methods in the above method embodiments are applicable to the embodiments of the device and can achieve the same technical effects.

[0180] An embodiment of the present invention provides a non-volatile computer storage medium, wherein the computer storage medium stores at least one executable instruction, and the computer executable instruction can execute the method for compensating the failed cell coverage area in any of the above method embodiments.

[0181] Figure 4 A schematic diagram of the structure of a computing device provided by an embodiment of the present invention is shown, and the specific embodiment of the present invention does not limit the specific implementation of the computing device.

[0182] like Figure 4 As shown, the computing device may include: a processor, a communications interface, a memory, and a communication bus.

[0183] The processor, the communication interface, and the memory communicate with each other via a communication bus. The communication interface is used to communicate with other devices such as a client or other server network elements. The processor is used to execute a program, specifically, to execute the relevant steps in the above-mentioned method for calculating the compensation of the failed cell coverage area of ​​the device.

[0184] Specifically, the program may include program codes including computer operation instructions.

[0185] The processor may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention. The one or more processors included in the computing device may be processors of the same type, such as one or more CPUs; or processors of different types, such as one or more CPUs and one or more ASICs.

[0186] The memory is used to store programs. The memory may include a high-speed RAM memory, and may also include a non-volatile memory, such as at least one disk memory.

[0187] The program can be specifically used to enable the processor to execute the compensation method for the failed cell coverage area in any of the above-mentioned method embodiments. The specific implementation of each step in the program can refer to the corresponding descriptions in the corresponding steps and units in the above-mentioned compensation method for the failed cell coverage area, which will not be repeated here. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the above-described devices and modules can refer to the corresponding process description in the above-mentioned method embodiments, which will not be repeated here.

[0188] The algorithm or display provided herein is not inherently related to any particular computer, virtual system or other device. Various general purpose systems can also be used together with the teachings based on this. According to the above description, it is obvious that the structure required for constructing this type of system. In addition, the embodiment of the present invention is not directed to any specific programming language either. It should be understood that various programming languages ​​can be utilized to realize the content of the embodiment of the present invention described herein, and the description of the above specific language is to disclose the best mode of the embodiment of the present invention.

[0189] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0190] Similarly, it should be understood that in order to streamline the embodiments of the present invention and to aid in understanding one or more of the various inventive aspects, in the above description of the exemplary embodiments of the present invention, the various features of the embodiments of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the disclosed method should not be interpreted as reflecting the following intention: that the claimed embodiments of the present invention require more features than the features explicitly recited in each claim. More specifically, as reflected in the claims below, the inventive aspects lie in less than all the features of the single embodiment disclosed above. Therefore, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present invention.

[0191] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and in addition they may be divided into a plurality of submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this manner may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature providing the same, equivalent or similar purpose.

[0192] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims below, any one of the claimed embodiments may be used in any combination.

[0193] The various component embodiments of the present invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. It should be understood by those skilled in the art that a microprocessor or digital signal processor (DSP) may be used in practice to implement some or all of the functions of some or all of the components according to the embodiments of the present invention. The embodiments of the present invention may also be implemented as a device or apparatus program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program implementing an embodiment of the present invention may be stored on a computer-readable medium, or may have the form of one or more signals. Such a signal may be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0194] It should be noted that the above embodiments illustrate rather than limit the present invention, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim listing a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be understood as limitations on the order of execution.

Claims

1. A method for compensating a failed cell coverage area, characterized in that: The method comprises: When a failure of the first cell is detected, acquiring data required for compensation of the coverage area after the failure of the first cell; Obtaining, according to the data, at least one second cell for compensating for the coverage area of ​​the first cell; Adjust the parameters of the at least one second cell to obtain the adjusted antenna weights of the at least one second cell; wherein, at least one first key point within the coverage area of ​​the first cell is obtained; a radial distance range and a north deflection angle between the at least one first key point and the coverage area of ​​the at least one second cell are obtained; and according to the radial distance range and the north deflection angle, the adjusted antenna weights of the at least one second cell are calculated, wherein the antenna weights include: an electronic downtilt angle, a vertical beam width, a horizontal beam width, and an electronic direction angle; According to the coverage of the at least one second cell under the adjusted antenna weight, the failed coverage of the first cell is compensated; wherein the average value of the first reference signal received power RSRP of the first coverage sector within the coverage of the first cell is obtained and an average value of a second reference signal received power RSRP of a second coverage sector within the coverage area of ​​the second cell ; Based on the average value of the second RSRP , obtain the coverage quality assessment value of the second coverage sector within the coverage range of the second cell ; According to the coverage quality evaluation value of the second coverage sector , obtain the signal coverage quality assessment value of the first coverage sector within the coverage range of the first cell ; According to the coverage quality evaluation value of the second coverage sector The average value of the second RSRP of the second coverage sector The first difference and the first preset threshold, and the signal coverage quality evaluation value of the first coverage sector The average value of the first RSRP of the first coverage sector and a second preset threshold, compensating for the failed coverage of the first cell, specifically comprising executing the following process: 71: Mark all failed cells P as unvisited, wherein the failed cell P is the first cell; 72: Randomly select an unvisited failed cell P and its coverage compensation cell set { },in,{ } is a set consisting of at least one second cell, i represents { } the i-th neighboring area; 72.1: Calculation , each compensation area , ,as well as ; 72.2: Calculation ;For each compensation cell, calculate ;in, is the preset threshold of the failed cell, To compensate for the preset threshold of the cell, is the preset difference of the failed cell, To compensate for the preset difference of the cell; 72.3: If , Among them, 72.2.1: if ,according to Sort the values ​​from large to small and enter the following for loop; 72.2.1.2: for i=1, for the current cell , 72.2.1.2.1: If the electronic downtilt angle is adjustable, the electronic downtilt angle is traversed by raising it by 1° in the positive direction. After each action is completed, recalculate , ; 72.2.1.2.1.1: if , community Still meets coverage; 72.2.1.2.1.1.1: if , it indicates that the optimization of the failed cell P is completed, and the process returns to step 72 to calculate the next failed cell; 72.2.1.2.1.1.2: else if >Previous , then jump back to 72.2.1.2.1 to continue adjustment and calculation; 72.2.1.2.1.1.3: else, description It has degenerated compared to the previous step, ending the loop of 72.2.1.2 and returning to the value of the previous step; 72.2.1.2.1.2: else, cell The coverage is no longer satisfied, so the loop of 72.2.1.2 ends and returns to the value of the previous step; 72.2.1.2.2: If the electronic direction angle is adjustable, the positive action of the electronic direction angle is to adjust the electronic direction angle by 3° clockwise. After each action is completed, recalculate , ; Repeat the logical steps of 72.2.1.2.1.1-72.2.1.2.1.2 to complete the traversal of the electronic direction angle; 72.2.1.2.3: If the horizontal beam width is adjustable, the horizontal beam width is increased by one level and the calculation is recalculated. , ; Repeat the logical steps of 72.2.1.2.1.1- 72.2.1.2.1.

2. At this time, if 72.2.1.2.1.1.2 takes effect, jump back to 72.2.1.2.1- 72.2.1.2.2 to traverse and optimize the electronic downtilt angle and electronic direction angle under the current horizontal beam width; 72.2.1.2.4: If the vertical beam width is adjustable, the vertical beam width is increased by one level and the calculation is recalculated. , ; Repeat the logical steps of 72.2.1.2.1.1-72.2.1.2.1.

2. If 72.2.1.2.1.1.2 takes effect, jump back to 72.2.1.2.1-72.2.1.2.2 to traverse and optimize the electronic downtilt angle and electronic direction angle under the current vertical beam width; 72.2.1.2.5: If the current horizontal and vertical beam widths are not adjustable, jump back to 72.2.1.2 for the next cell. Perform optimization calculations.

2. The method for compensating for a failed cell coverage area according to claim 1, characterized in that: Obtaining, according to the data, at least one second cell for compensating for the coverage area of ​​the first cell, comprising: In the coverage area of ​​the first cell, a cell having a reference signal received power RSRP signal strength greater than a first preset value is obtained as a candidate cell; The candidate cells are screened to obtain at least one second cell for compensating for the coverage area of ​​the first cell.

3. The method for compensating for a failed cell coverage area according to claim 1, characterized in that: Obtaining a radial distance range between the at least one first key point and the coverage area of ​​the at least one second cell includes: Obtaining a distance between the at least one first key point and at least one second key point within the coverage area of ​​the at least one second cell; According to the distance, a radial distance range is obtained.

4. The method for compensating for a failed cell coverage area according to claim 1, characterized in that: Also includes: During the failure of the first cell, if the number of signal quality warnings of the first cell received is greater than X times, the parameters of at least one second cell are adjusted again, and the failed coverage range of the first cell is compensated according to the coverage range under the antenna weight after the at least one second cell is adjusted again; or During the failure of the first cell, if the number of signal quality warnings received from the second cell is greater than Y times, the second cell is removed from the neighboring cell set consisting of at least one second cell to obtain an updated neighboring cell set. If the number of second cells with adjustable weights in the updated neighboring cell set is not zero, compensation for the failed coverage of the first cell is performed again; if the number of second cells with adjustable weights in the updated neighboring cell set is zero, an alarm is output that the first cell cannot be compensated through weight adjustment.

5. A compensation device for a failed cell coverage area, characterized in that: The device comprises: A first acquisition module is used to acquire data required for coverage area compensation after failure of the first cell when failure of the first cell is detected; A second acquisition module, configured to obtain, according to the data, at least one second cell for compensating for the coverage area of ​​the first cell; An adjustment module is used to adjust the parameters of the at least one second cell to obtain the adjusted antenna weights of the at least one second cell; wherein, at least one first key point within the coverage area of ​​the first cell is obtained; a radial distance range and a north deflection angle between the at least one first key point and the coverage area of ​​the at least one second cell are obtained; and according to the radial distance range and the north deflection angle, the adjusted antenna weights of the at least one second cell are calculated, wherein the antenna weights include: an electronic downtilt angle, a vertical beam width, a horizontal beam width, and an electronic direction angle; A compensation module is used to compensate for the failed coverage of the first cell according to the coverage of the at least one second cell under the adjusted antenna weight; wherein the average value of the first reference signal received power RSRP of the first coverage sector within the coverage of the first cell is obtained and an average value of a second reference signal received power RSRP of a second coverage sector within the coverage area of ​​the second cell ; Based on the average value of the second RSRP , obtain the coverage quality assessment value of the second coverage sector within the coverage range of the second cell ; According to the coverage quality evaluation value of the second coverage sector , obtain the signal coverage quality assessment value of the first coverage sector within the coverage range of the first cell ; According to the coverage quality evaluation value of the second coverage sector The average value of the second RSRP of the second coverage sector The first difference and the first preset threshold, and the signal coverage quality evaluation value of the first coverage sector The average value of the first RSRP of the first coverage sector and a second preset threshold, compensating for the failed coverage range of the first cell; The device is further configured to perform the following process: 71: Mark all failed cells P as unvisited, wherein the failed cell P is the first cell; 72: Randomly select an unvisited failed cell P and its coverage compensation cell set { },in,{ } is a set consisting of at least one second cell, i represents { } the i-th neighboring area; 72.1: Calculation , each compensation area , ,as well as ; 72.2: Calculation ;For each compensation cell, calculate ;in, is the preset threshold of the failed cell, To compensate for the preset threshold of the cell, is the preset difference of the failed cell, To compensate for the preset difference of the cell; 72.3: If , Among them, 72.2.1: if ,according to Sort the values ​​from large to small and enter the following for loop; 72.2.1.2: for i=1, for the current cell , 72.2.1.2.1: If the electronic downtilt angle is adjustable, the electronic downtilt angle is traversed by raising it by 1° in the positive direction. After each action is completed, recalculate , ; 72.2.1.2.1.1: if , community Still meets coverage; 72.2.1.2.1.1.1: if , it indicates that the optimization of the failed cell P is completed, and the process returns to step 72 to calculate the next failed cell; 72.2.1.2.1.1.2: else if >Previous , then jump back to 72.2.1.2.1 to continue adjustment and calculation; 72.2.1.2.1.1.3: else, description It has degenerated compared to the previous step, ending the loop of 72.2.1.2 and returning to the value of the previous step; 72.2.1.2.1.2: else, cell The coverage is no longer satisfied, so the loop of 72.2.1.2 ends and returns to the value of the previous step; 72.2.1.2.2: If the electronic direction angle is adjustable, the positive action of the electronic direction angle is to adjust the electronic direction angle by 3° clockwise. After each action is completed, recalculate , ; Repeat the logical steps of 72.2.1.2.1.1-72.2.1.2.1.2 to complete the traversal of the electronic direction angle; 72.2.1.2.3: If the horizontal beam width is adjustable, the horizontal beam width is increased by one level and the calculation is recalculated. , ; Repeat the logical steps of 72.2.1.2.1.1- 72.2.1.2.1.

2. At this time, if 72.2.1.2.1.1.2 takes effect, jump back to 72.2.1.2.1- 72.2.1.2.2 to traverse and optimize the electronic downtilt angle and electronic direction angle under the current horizontal beam width; 72.2.1.2.4: If the vertical beam width is adjustable, the vertical beam width is increased by one level and the calculation is recalculated. , ; Repeat the logical steps of 72.2.1.2.1.1-72.2.1.2.1.

2. If 72.2.1.2.1.1.2 takes effect, jump back to 72.2.1.2.1-72.2.1.2.2 to traverse and optimize the electronic downtilt angle and electronic direction angle under the current vertical beam width; 72.2.1.2.5: If the current horizontal and vertical beam widths are not adjustable, jump back to 72.2.1.2 for the next cell. Perform optimization calculations.

6. A computing device comprising: A processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus; The memory is used to store at least one executable instruction, and the executable instruction enables the processor to perform operations corresponding to the method for compensating a failed cell coverage area according to any one of claims 1 to 4.

7. A computer storage medium, wherein at least one executable instruction is stored in the storage medium, and wherein the executable instruction enables a processor to execute operations corresponding to the method for compensating a failed cell coverage area according to any one of claims 1 to 4.

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