Wireless telecommunications network

Abstract

The present invention provides a method for determining the performance of a radio access network RAN ​​of a telecommunication network and a system for implementing the method, wherein the radio access network covers an area, and the area is divided into a plurality of unit cells, and the method comprises the following steps: receiving a measured performance value of the RAN in at least one unit cell among the plurality of unit cells; receiving a simulated performance value of the RAN in each of the plurality of unit cells; identifying a unit cell associated with both the measured performance value and the simulated performance value; for the identified unit cell, calculating a difference function between the simulated performance value of the identified unit cell and the measured performance value of the identified unit cell; applying the difference function to the simulated performance value of at least one unit cell adjacent to the identified unit cell, thereby obtaining a modified simulated performance value of the adjacent unit cell.

Description

Technical Field

[0001] The present invention relates to wireless telecommunication networks. More particularly, the present invention relates to a method of determining the performance of a wireless transmitter in a wireless telecommunication network. Background Art

[0002] Wireless telecommunication networks, such as cellular telecommunication networks, include multiple transceivers arranged around a geographic area. These transceivers are often referred to as access points (APs), and each AP has its own coverage area, which is defined as the geographic area that the AP provides service for (i.e., based on the maximum transmission distance from the AP). It is beneficial for the network operator to determine the performance of each AP so that each existing or new AP can be configured to improve the overall performance in the network.

[0003] One method of determining the performance of an AP in a wireless telecommunications network is by performing a Field Drive Test (FDT). FDT is performed by taking performance measurements (e.g., signal strength) of one or more APs. In FDT, each AP uses a specific configuration profile in which each configuration parameter (e.g., antenna tilt angle, gain, radiation pattern, mechanical azimuth, altitude, position, etc.) takes a value from a set of possible values ​​for the configuration parameter. Since performance varies based on the specific configuration profile used by the AP (and possible neighboring APs in the presence of overlapping coverage areas), the results of FDT are only valid for the specific configuration profile used in FDT. Therefore, FDT gives a very accurate measurement of the performance of one or more APs, but measuring all APs in all configurations simultaneously has high resource requirements (which would be necessary in order to determine the best configuration profile for each AP).

[0004] Another way to determine the performance of an AP in a wireless telecommunications network is by utilizing computational simulation tools that predict the performance of an AP over a coverage area for a given configuration profile. Network operators can substantially reduce their planning costs by utilizing these tools and simulating the performance of each AP using each configuration profile. However, the simulated value of each performance measurement may differ from the actual measurement result. Summary of the invention

[0005] According to a first aspect of the present invention, there is provided a method for determining the performance of a radio access network RAN ​​of a telecommunication network, the radio access network covering an area, and the area being divided into a plurality of unit cells, the method comprising the following steps: receiving a measured performance value of the RAN in at least one unit cell among the plurality of unit cells; receiving a simulated performance value of the RAN in each of the plurality of unit cells; identifying a unit cell associated with both the measured performance value and the simulated performance value; for the identified unit cell, calculating a difference function between the simulated performance value of the identified unit cell and the measured performance value of the identified unit cell; applying the difference function to the simulated performance value of at least one unit cell adjacent to the identified unit cell, thereby obtaining a modified simulated performance value of the adjacent unit cell.

[0006] Individual unit cells associated with both measured performance values ​​and simulated performance values ​​may be identified, and a difference function may be calculated for each such identified unit cell, and the method may further include the following steps: applying the difference function to the simulated performance value of at least one unit cell adjacent to each such identified unit cell, thereby generating a modified simulated performance value for the adjacent unit cell.

[0007] The difference function may be applied to the simulated performance value of at least one unit cell adjacent to the adjacent unit cell, thereby generating a modified simulated performance value of the adjacent unit cell, so as to form a continuous region of unit cells around each identified unit cell.

[0008] The method may be performed for multiple configuration profiles of the RAN, thereby generating a first modified simulated performance value of a first neighboring unit cell for a first configuration profile among the multiple configuration profiles, and also generating a second modified simulated performance value of a second neighboring unit cell for a second configuration profile among the multiple configuration profiles.

[0009] The method may further include the step of configuring the RAN based on the modified simulated performance value of the neighboring unit cell.

[0010] The step of configuring the RAN may be based on the first modified simulated performance value and the second modified simulated performance value.

[0011] According to a second aspect of the present invention, there is provided a computer program comprising instructions which, when executed by a computer, cause the computer to perform the steps of the first aspect of the present invention. The computer program may be stored on a computer readable carrier medium.

[0012] According to a third aspect of the present invention, there is provided a system for a telecommunications network, the system comprising one or more nodes configured to perform the steps of the first aspect of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to better understand the present invention, embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:

[0014] Figure 1 is a schematic diagram of a wireless telecommunications network according to a first embodiment of the present invention;

[0015] Figure 2 Yes Description Figure 1 a map of the geographical area within the wireless telecommunications network;

[0016] Figure 3 yes Figure 2 a map of the geographic area showing measurement locations;

[0017] Figure 4 yes Figure 2 a diagram of a geographical area showing a first cluster of cells and a second cluster of cells around two measurement locations;

[0018] Figure 5 yes Figure 2 a map of a geographic area showing a plurality of clusters around a plurality of measurement locations;

[0019] Figure 6 is a flow chart showing a first sub-process of an embodiment of the method of the present invention;

[0020] Figure 7 is a diagram showing an area defined by a cluster of cells surrounding a first measurement location for a first configuration profile;

[0021] Figure 8 It is shown Figure 7 , showing measurement locations of a first configuration profile, a second configuration profile, and a third configuration profile;

[0022] Fig. 9 is a diagram showing an area defined by a cluster of cells around a second measurement location of a first configuration profile, showing measurement locations of the first configuration profile and a third configuration profile and normalized prediction values ​​of the second configuration profile and the third configuration profile;

[0023] Fig.10 is a probability distribution function of the first combination and the second combination of configuration profiles; and

[0024] Fig.11 It is shown Figure 6 Flowchart of the second sub-process of an implementation method of FIG. DETAILED DESCRIPTION

[0025] Now refer to Figure 1A first embodiment of a wireless telecommunication network of the present invention is described. In this embodiment, the wireless telecommunication network is a cellular telecommunication network 1 having a base station 10, wherein the base station 10 has an associated coverage area 15. The base station 10 is configured to transmit wireless signals about the coverage area 15 according to a specific cellular telecommunication protocol, such as Long Term Evolution LTE.

[0026] In this embodiment, the base station 10 includes a first transceiver, a second transceiver, and a third transceiver, wherein each transceiver uses one of a plurality of configuration profiles. The configuration profile specifies the value of each of a plurality of configuration parameters (e.g., antenna tilt angle, gain, mechanical azimuth, altitude, position, etc.), wherein the value of any configuration parameter is one of a range of possible (discrete or continuous) values ​​of the configuration parameter.

[0027] An embodiment of a method of identifying a configuration profile for each of the first transceiver, the second transceiver, and the third transceiver of the base station 10 will now be described. In the following embodiment, the first transceiver, the second transceiver, and the third transceiver may use nine possible configuration profiles (without duplication). The embodiment includes a first sub-process and a second sub-process, and Figures 2 to 6 The first sub-process is shown in . Figure 2 FIG. 1 is a diagram showing a geographical area of ​​interest within the coverage area 15 of the base station 10. The geographical area is divided into an array of unit cells. Figure 2 A rectangular geographical area is shown in FIG, but for the purpose of this embodiment, any shape of geographical area may be divided into an array of unit cells. A base station is located in cell B6 (indicated by a circle in the unit cell).

[0028] In such Figure 6 In the first step (step S1) of the iterative method shown in the flowchart of FIG. 1 , a computational simulation tool (e.g., Forsk Atoll) is used to predict the values ​​of performance parameters (e.g., reference signal received power (RSRP)) in each unit cell of the geographic area when the first configuration profile of nine possible configuration profiles is used. These simulation values ​​for each unit cell are stored in a memory.

[0029] In step S3, the base station 10 broadcasts a signal using the first configuration profile using only its first transceiver. In step S5, a field drive test (FDT) is performed (e.g., using a Rohde & Schwarz signal and spectrum analyzer) to determine performance measurements (e.g., RSRP) when the base station 10 uses the first configuration profile. These measurements also include location data representing the geographic location where the FDT was performed. In step S7, unit cells of the geographic area including the location of each corresponding FDT are identified. In step S9, the performance measurements and their associated unit cell identifiers are stored in a memory. Figure 3 An example of an FDT comprising six separate performance measurements made with respect to a geographical area is shown in FIG.

[0030] In step S11, the difference between 1) the performance measurement result in the unit cell where FDT is performed and 2) the simulation value of the unit cell is calculated. In this example, the difference is calculated for six unit cells (i.e., D1, I2, H4, E7, C10, and J10) where FDT is performed.

[0031] In step S13, a cluster of unit cells is identified for each unit cell in which FDT is performed, wherein the cluster of unit cells includes the following unit cells: FDT is performed in the unit cells, and the unit cells form a continuous area of ​​multiple unit cells, each of which has a simulation value within a deviation threshold of the simulation value of the unit cell in which FDT is performed. Figure 4 A first cluster of unit cells and a second cluster of unit cells are shown, the first cluster of unit cells being identified as being within the deviation threshold of unit cell C10, and the second cluster of unit cells being identified as being within the deviation threshold of unit cell E7. It can be seen that two unit cells (C8 and D8) are members of both the first cluster and the second cluster of cells.

[0032] In step S15, the simulated RSRP of each unit cell within the unit cell cluster is normalized by adding the simulated RSRP and the difference of the cluster of unit cells of which the unit cell is a member. If the unit cell is a member of multiple clusters, the difference is the average of the differences of all clusters of which the unit cell is a member (e.g., the difference of unit cells C8 and D8 will be the average of the differences of the first cluster and the second cluster of unit cells).

[0033] like Figure 5 As shown, after these steps, the coverage area is divided into a plurality of unit cells, wherein each unit cell includes: 1) a measured value (indicated by a star), 2) a normalized simulated value based on a simulated value and a difference value calculated for one or more unit cell clusters of which the unit cell is a member (indicated by text identifying the unit cell of the cluster for which FDT is performed), or 3) a simulated value for which the unit cell is not a member of a cluster (indicated by a blank unit cell). These values ​​(measured values, normalized simulated values, or simulated values) for each unit cell are stored in a memory.

[0034] The first iteration of the first sub-process is now complete, so that the value of each unit cell at the time of the first configuration profile in the nine configuration profiles has been calculated and stored in the memory. Then, the sub-process loops back to step S1, and all steps are repeated for the second configuration profile in the nine configuration profiles. In summary, a calculation simulation tool is used to calculate the simulation value of each unit cell when using the second configuration profile, and the base station only uses its first transceiver to broadcast the signal using the second configuration profile, performs FDT, calculates the difference between each FDT measurement result and the corresponding simulation value, identifies the unit cell cluster of each unit cell for which each FDT measurement is performed, and determines the normalized simulation value of each unit cell. The measured value, normalized simulation value, or simulation value of the performance parameter of the second configuration profile of each unit cell is stored in the memory.

[0035] The method is similarly repeated for all 9 configuration profiles, so that the measured values, normalized simulated values, or simulated values ​​of the performance parameters of each configuration profile for each unit cell are stored in the memory. The first sub-process is then completed, and the second sub-process is performed on the data to identify a combination of three configuration profiles for the first transmitter, the second transmitter, and the third transmitter. Because the data includes normalized simulated values, the calculation combines the accuracy of real-world measurement data from FDT and the simplicity of computational simulation tools. In other words, the method utilizing these normalized simulation values ​​can identify a combination of configuration profiles that is more accurate than a method based solely on computational simulation tools, but uses fewer resources than a method based solely on FDT. Reference will now be made to Figures 7 to 11 A second sub-process of determining a combination of configuration profiles for transmitters of a base station is described. The second sub-process is iteratively performed to analyze each combination of configuration profiles in the nine configuration profiles.

[0036] In the second subprocess ( Fig.11 In the first step (step S21) of the first iteration of the process (shown in the flowchart of ), a combination of configuration profiles is identified for analysis, and data for each configuration profile in this identified combination from the first subprocess is retrieved. In this example, the combination is the first configuration profile, the second configuration profile and the third configuration profile, so the data of the first configuration profile, the second configuration profile and the third configuration profile are retrieved. In step S23, the data of one configuration profile of the three configuration profiles in the identified combination is selected as reference data. This selection is based on the determination of the configuration profile with the highest measurement value count (and therefore the highest unit cell cluster count). In this example, the first configuration profile is selected.

[0037] As described above, the data of the first configuration profile includes one or more unit cell clusters. Then, the first unit cell cluster in the data of the first configuration profile is analyzed to identify the configuration profile with the best performance for the geographical area defined by the first cluster (step S25). Figure 7 The first cluster is shown in , showing the boundary of the geographical area defined by the first unit cell cluster of the measured values ​​around the unit cell D1. The data of the measured values ​​are analyzed together with the data of the measured values, normalized simulated values ​​or simulated values ​​of the performance parameters of the corresponding unit cells of the second configuration profile and the third configuration profile (i.e., the unit cells corresponding to the same geographical area of ​​the first unit cell cluster) to determine whether the first configuration profile, the second configuration profile or the third configuration profile has the best performance.

[0038] This analysis can be done by one of several techniques. Figure 8 A first example technique is shown in , where the boundaries of a geographic area defined by a first unit cell cluster of a first configuration profile are shown, and data for a second configuration profile and a third configuration profile include measured values ​​of performance parameters in the corresponding unit cells. These values ​​can then be analyzed to determine whether the first configuration profile, the second configuration profile, or the third configuration profile has the best performance for the performance parameter.

[0039] exist Fig. 9 A second example technique is shown in , which shows the boundaries of a geographic area defined by a second cluster of unit cells of a first configuration profile (a cluster of measured values ​​around unit cell H4). In this case, the data for the second and third configuration profiles includes normalized simulated values ​​for the second configuration profile and both measured values ​​and normalized simulated values ​​for the third configuration profile. Since the measured values ​​are more accurate than the normalized simulated values, the measured values ​​of the first and third configuration profiles and the normalized simulated values ​​of the second configuration profile are analyzed to determine the best performer in the second cluster of unit cells for the performance parameter (in other words, the normalized simulated values ​​of the third configuration profile are ignored).

[0040] Step S25 is performed for each unit cell cluster in the data of the first configuration profile, thereby determining the best performing configuration profile for each cluster in the data of the first configuration profile. Then, it is determined whether the data of the second configuration profile and the third configuration profile (i.e., the configuration profile that is not selected as a reference) includes measurements that were not considered during the analysis of the first configuration profile (i.e., the measurements associated with the unit cells of the unit cells in any unit cell cluster that does not correspond to the first configuration profile in the data of the second configuration profile and the third configuration profile). If not, the method proceeds to step S27 (described below). If more than one configuration profile includes unused measurements, one of these configuration profiles is selected as a reference by determining which configuration profile has the highest count of measurements. If only one configuration profile includes one or more unused measurements, that configuration profile is selected as a reference.

[0041] The method then loops back to step S25 so that each unit cell cluster is analyzed for unused measurements in the data of the reference configuration profile to identify the configuration profile with the best performance for the geographic area defined by each cluster. Once all unit cell clusters have been analyzed for unused measurements of the reference configuration profile, step S25 is repeated for the unused measurements of the configuration profile with the next highest measurement count. Once all measurements of all configuration profiles of the combination have been considered, the method proceeds to step S27.

[0042] In step S27, a probability density function of values ​​is then recorded, which describes the variability of the performance parameter using the measured values, normalized simulated values, or simulated values ​​for each unit cell for the combination of configuration profiles. For example, if the data of the first configuration profile includes two clusters, and it is determined that the second configuration profile is the best performing configuration profile for the first cluster, and the third configuration profile is the best performing configuration profile for the second cluster, then the probability density function is compiled using the measured values, normalized simulated values, or simulated values ​​for each unit cell corresponding to the first cluster of the second configuration profile and the measured values, normalized simulated values, or simulated values ​​for each unit cell corresponding to the second cluster of the third configuration profile.

[0043] Then, the second sub-process is repeated for all possible combinations of configuration profiles, and a probability density function of the value of each combination is obtained. Fig.10 An example of two probability density functions for two combinations of configuration profiles is shown. The network operator may then select a combination of configuration profiles by comparing the probability density functions (step S29).

[0044] The above embodiments relate to cellular telecommunication networks. However, those skilled in the art will appreciate that the present invention is applicable to other forms of wireless telecommunication networks, and even to combinations of wireless telecommunication networks (e.g., a cellular network comprising base stations and a wireless wide area network comprising wireless access points, each having a corresponding set of configuration profiles). Those skilled in the art will also appreciate that the configuration profiles used above are examples and may cover a variety of performance parameters that have an impact on the performance of a wireless telecommunication network.

[0045] The above embodiments are performed on a geographical area within the coverage area of ​​a base station (i.e., it is a part of the coverage area). However, this is not necessary. The geographical area may cover the entire coverage area of ​​a base station, or may cover the coverage areas (or parts thereof) of multiple base stations.

[0046] Those skilled in the art will appreciate that it is not essential that the computation simulation step ( S1 ) and the FDT steps (steps S3 to S9 ) be performed in the order described, such that step S1 may be performed at any point in the process before S11 .

[0047] In the above embodiment, the simulation values ​​and FDT are performed based on the base station using its first transceiver. However, this is not necessary. The simulation and FDT can be performed based on different transmitters (such as test antennas) that can be deployed (or simulated).

[0048] Those skilled in the art will also appreciate that the deviation threshold (which defines the range of the unit cell cluster around each measurement value) can be configured by the network operator. In one implementation, the deviation threshold can be inversely proportional to the count of the measurement value. Therefore, if the count of the measurement value is relatively small, the deviation threshold is relatively large in order to generate a larger number of normalized simulation values ​​(thereby compensating for the lack of measurement values). In addition, the deviation threshold also determines whether the unit cell has a normalized simulation value or a simulation value. The simulation value may or may not be used for subsequent analysis of the second sub-process.

[0049] Those skilled in the art will appreciate that the benefits of the present invention may be achieved if at least one of the configuration profiles in a combination of configuration profiles comprises measured values ​​and normalized simulated values, whereby the other configuration profiles of the combination may comprise only simulated values. It may be relevant if the configuration profile is based on the state of a prior art transmitter that has not yet been deployed, but whose characteristics may be simulated.

[0050] As described above, for one or more combinations of configuration profiles, normalized simulation values ​​can be used to determine the performance of multiple transceivers in the wireless telecommunications network, and further identify a combination of configuration profiles that meets the operator's requirements. The above-mentioned second embodiment is an example of how a combination can be identified, but those skilled in the art will understand that other techniques can be used. In addition, it is not essential to use these normalized simulation values ​​to identify a combination of configuration profiles, because they can be used to determine the performance of a single configuration profile for a transmitter in the wireless telecommunications network (for example, in a unit cell with only performance simulation values ​​but no measured values). This can be used by operators in network planning scenarios, such as when reconfiguring one or more transmitters and / or deploying one or more transmitters in a wireless telecommunications network.

[0051] A person skilled in the art will appreciate that any combination of features is possible within the scope of the claimed invention.

Claims

1. A method for determining the performance of a radio access network RAN ​​of a telecommunication network, the radio access network covering an area and the area being divided into a plurality of unit cells, the method comprising the following steps: receiving a measured performance value of the RAN in at least one unit cell among the plurality of unit cells; receiving a simulation performance value of the RAN in each of the plurality of unit cells; identifying a unit cell associated with both the measured performance value and the simulated performance value; For the identified unit cell, calculating a difference function between a simulated performance value of the identified unit cell and a measured performance value of the identified unit cell; determining that a simulated performance value associated with at least one unit cell adjacent to the identified unit cell is within a deviation threshold of the simulated performance value of the identified unit cell; applying the difference function to the simulated performance value associated with the at least one unit cell adjacent to the identified unit cell, thereby generating a modified simulated performance value for the adjacent unit cell; as well as The RAN is configured based on the modified simulated performance value of the neighboring unit cell.

2. The method according to claim 1, wherein: The identifying step comprises identifying each unit cell associated with both the measured performance value and the simulated performance value, and the calculating step comprises calculating a difference function for each such identified unit cell, and the determining step comprises determining that a simulated performance value associated with at least one unit cell adjacent to each such identified unit cell is within the deviation threshold of the simulated performance value of the identified unit cell, the method further comprising the following steps: The difference function is applied to the simulated performance value associated with the at least one unit cell adjacent to each such identified unit cell, thereby generating a modified simulated performance value for the adjacent unit cell.

3. The method according to claim 2, further comprising the steps of: Determine that the simulation performance value associated with at least one unit cell adjacent to the neighboring unit cell is within the deviation threshold of the simulation performance value of the identified unit cell, wherein the difference function is applied to the simulation performance value of the at least one unit cell adjacent to the adjacent unit cell to obtain a modified simulation performance value of the adjacent unit cell, so as to form a continuous area of ​​unit cells around each identified unit cell.

4. The method according to claim 3, wherein: The method is performed for multiple configuration profiles of the RAN, thereby generating a first modified simulated performance value of a first neighboring unit cell for a first configuration profile among the multiple configuration profiles, and also generating a second modified simulated performance value of a second neighboring unit cell for a second configuration profile among the multiple configuration profiles.

5. The method according to claim 4, wherein: The step of configuring the RAN is based on the first modified simulation performance value and the second modified simulation performance value.

6. A computer-readable carrier medium comprising a computer program, the computer program comprising instructions which, when the computer program is executed by a processor of a node of a telecommunications network, cause the processor to perform the method according to any one of claims 1 to 5.

7. A system for a telecommunication network, the system comprising one or more nodes, the one or more nodes being configured to perform the method according to any one of claims 1 to 5.

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