This section describes the process of GSM measurement report (MR) analysis. 6.3 Obtaining GSM MR Analysis Data
This section describes how to enable the Nastar to obtain GSM measurement report (MR) analysis data. You can create a neighboring cell measurement data E2E task to turn on some performance counters switch, create a collection task to enable the Nastar to collect analysis data and create a data import task so that the Nastar imports the collected analysis data into the database.
6.4 Creating GSM MR Analysis Tasks
This section describes how to create GSM MR analysis tasks. After you create a GSM MR analysis task, the Nastar periodically analyzes GSM performance data, GSM configuration data, and engineering parameters in the Nastar database. By querying analysis results, you can learn about the status of the entire radio network so that problems can be located and solved efficiently. 6.5 Querying GSM MR Overview Analysis Results
This section describes how to query the GSM measurement report (MR) overview report. An MR report includes the following information about a measurement cell: uplink and downlink levels, uplink and downlink quality, timing advance (TA), and link balance. You can learn the TRX and cell coverage, radio link quality, and subscriber distribution directly from the information in the analysis results. A GSM MR overview report consists of GSM BSC analysis results, GSM cell group analysis results, TopN TRX analysis results, and GSM MR theme analysis results.
This section describes how to query GSM measurement report (MR) results. Through this function, you can query the detailed information about TopN TRXs and TRXs that meet the filter conditions of the cell where multiple TopN TRXs or TRXs that meet the filter conditions exist.
6.7 Comparing GSM MR Analysis Results
This section describes how to compare the GSM Measurement Report (MR) analysis results. After the network is optimized or the equipment is upgraded, you can compare two GSM MR analysis results generated in two time segments to check the differences between the values of the same counters in two time segments. This function helps you learn about the detailed network performance differences in two time segments and quickly evaluate the network optimization effect.
6.8 Exporting GSM MR Overview Reports
This section describes how to export GSM MR overview reports. You can export GSM MR overview analysis results as .csv files.
6.9 Technical Specifications for GSM MR Analysis
This section describes the technical specifications for GSM MR analysis. 6.10 Reference for the GSM MR Analysis GUI
This section describes the interface for GSM MR analysis and the relevant parameters. Before performing relevant operations, familiarize yourself with GSM MR analysis functions.
6.1 Basic Knowledge of GSM MR Analysis
This section provides the basic knowledge of GSM measurement report (MR) analysis, such as the MR analysis function, TopN counters, and MR theme analysis types. The basic knowledge helps you perform GSM MR analysis.
6.1.1 GSM MR Analysis
This section describes the GSM MR analysis function. A GSM measurement report (MR) includes the following information about the measurement cell: uplink level, downlink level, uplink quality, downlink quality, timing advance (TA) distribution, and link balance
information. The information in MRs helps you learn the coverage, quality, and user distribution of TRXs and cells. In addition, the Nastar processes the required information and displays radio link information directly, helping you solve network problems.
MR Overview Analysis Results
The MR overview analysis results include the overview information about the radio network performance, the distribution of TopN TRXs and TRXs that meet the filter conditions of each BSC and cell group, the TopN TRXs for which the value of each radio link counter is the lowest, and the classification of the TRXs that meet the filter conditions based on theme analysis.
NOTE
TopN TRXs indicate the N TRXs (currently, the default value of TopN is 99) with the poorest performance indicated by a selected radio link counter.
You can view the daily MR overview analysis results to learn about the information about the TRXs that meet the filter conditions of each BSC, each cell group, and the entire network. You can also check for other problem in the cell where a TRX that meet the filter conditions or TopN TRXs are located and analyze these TRXs that meet the filter conditions.
The problem analysis themes are as follows:
l Weak coverage analysis. TRXs with a low TA value, a low level, and poor signal quality are listed.
l Interfered cells. Cells with a high level and poor quality are listed.
l Over coverage analysis. You can compare the TA values and the number of MRs to analyze the traffic distribution and to check whether the cell is an over coverage cell.
l Unbalanced uplink and downlink. The cells in which the uplink and downlink levels are greatly unbalanced.
l Other problems. Problems on the network, such as a few of generated MRs, no traffic, and low traffic, are listed.
The analysis results can be displayed in a table or a bar chart to provide the radio link quality, level, traffic distance distribution, and link balance. Analysis of the problems and suggestions are provided to help you quickly analyze and locate the quality problems that occur on the wireless network.
MR Query
During network performance analysis and optimization, when problem cells (such as a cell whose call drop rate is high or number of handover failures is large) are found, you can query
the MR information about these cells and the radio links of the TRXs in the cells through the Nastar.
You can set the time and cell objects before the query. The MR information about these cells is displayed in the result window. In addition, you can enable the Nastar to further query the TRX information. Through the comparison and query of different TRXs in cells, you can locate more complicated network problems effectively.
The query results are displayed in a table or a bar chart to provide the radio link quality and subscriber distribution of each TRX.
MR Comparison Analysis
After network upgrade and optimization such as the adjustment of antennas and modification of parameter settings, you can compare the quality and coverage of the entire network, BSCs, cell groups, or cells with the quality and coverage obtained before the network upgrade and optimization, or you can compare the quality and coverage of different time segments during network upgrade and optimization.
The comparison analysis results are displayed in a table or a bar chart.
6.1.2 TopN KPIs
This section describes TopN KPIs related to the performance analysis. The KPIs include average quality of the received signals at uplink and downlink, average levels received at uplink and downlink, timing advance (TA) average distribution, and uplink and downlink balance.
Received Signal Quality
The quality of received signals is divided into seven classes from 1 to 7 according to the bit error rate. Each class corresponds to different bit error rates. Higher class indicates poorer quality of received signals. Class 1 indicates the minimum bit error rate and the best quality of received signals. Class 7 indicates the maximum bit error rate and the poorest quality of received signals.
Table 6-1 describes the relation between the quality classes of received signals and the bit error rate.
Table 6-1 Relation between the quality classes of the received signals and bit error rate Quality
Class of Received Signals
Bit Error Rate (%)
1 [0.2, 0.4) 2 [0.4, 0.8) 3 [0.8, 1.6) 4 [1.6, 3.2) 5 [3.2, 6.4) 6 [6.4, 12.8)
Quality Class of Received Signals
Bit Error Rate (%)
7 ≥ 12.8
Received Level
The received signal level is divided into seven classes according to level values. Each class corresponds to different ranges of received levels. Class 1 indicates the lowest received level and class 7 indicates the highest received level.
Table 6-2 describes the relation between the received levels and the seven classes.
Table 6-2 Relation between the received levels and the seven classes Class of Received Level Received Level (dBm) 1 (-100, -95] 2 (-95, -90] 3 (-90, -85] 4 (-85, -80] 5 (-80, -75] 6 (-75, -70] 7 > -70
TA(Timing Advance)
Timing advance (TA) is a counter used to describe the distance with time and is used for coverage analysis. The header of a measurement report (MR) sent from a mobile station (MS) to a BTS carries the delay measured by the MS. After obtaining the delay, the BTS monitors the time when a call reaches and sends an instruction to the MS on a downlink channel every 480 ms to specify the advanced sending time for the MS. This time is termed TA, ranging from 0 to 63. The MRs usually contain TA values ranging from 0 to 10. The MRs contain TA values higher than 10 are incremented by certain TA ranges. In a TA distribution chart generated on the basis of GSM MR analysis results, each bar chart shows the percentage of the number of MRs within a TA range to the total number of MRs.
Uplink and Downlink Balance
The MR received by the BSC contains the uplink receive level and downlink receive level. The result (in dB), which is obtained by subtracting the uplink receive level and the sensitivity difference between the MS and the BTS from the downlink receive level, is divided into 11
classes from 1 to 11. Table 6-3 describes the relations between classes and values of the Uplink and Downlink Balance Level counter.
Table 6-3 Description of link balance classes Uplink and
Downlink Balance Class
Downlink Receive Level- Uplink Receive Level- 6 (dB)
1 ≤ -15 2 -14, -13, -12, -11 3 -10, -9, -8 4 -7, -6, -5 5 -4, -3, -2 6 -1, 0, 1 7 2, 3, 4 8 5, 6, 7 9 8, 9, 10 10 11, 12, 13, 14 11 ≥ 15 NOTE
The number 6 in the formula "Downlink receive level - Uplink receive level - 6 (dB)" refers to the sensitivity difference between the MS and the BTS.
If the statistical result indicates that the uplink and downlink are mostly in balance class 1, the downlink loss is excessively high or the downlink transmit power is excessively low. If the statistical result indicates that the uplink and downlink are mostly in balance class 11, the uplink loss is excessively high or the uplink transmit power is excessively low. According to the statistical result, you can locate the faults that may occur on the transmit and receive channels, such as the TRX or antenna feeder.
6.1.3 GSM MR Theme Analysis
This section describes the themes involved in the GSM MR theme analysis, such as uplink interference, downlink interference, uplink weak coverage, downlink weak coverage, TRX weak coverage, over coverage, link balance (uplink problem), link balance (downlink problem), and other problems. This section also provides the solutions to these problems.
The MR theme analysis is classified into nine types based on themes. The system provides different operation suggestions for each type of MR theme analysis. For details, see Table 6-4.
Table 6-4 Themes and operation suggestions
Theme Description Suggestion
Uplink interferen ce
The uplink interference results in high level and poor quality.
Change the ARFCN and check whether radio interference sources exist in the coverage area. After the ARFCN is changed, enable the uplink interference analysis function to analyze the interference according to the uplink frequency distribution that is measured by TRXs. Downlink
interferen ce
The downlink interference results in high level and poor quality.
Change the ARFCN and check whether radio interference sources exist in the coverage area. After the ARFCN is changed, use an MS to search for frequencies within the cell coverage area where the TRX is transmitted, and view the downlink frequency status.
Uplink weak coverage
The signal loss on the uplink of the TRX is large.
Check the cables connecting the combiner and the TRX, and cable connections in the antenna system. Ensure that the cable connections are proper and secure, and then locate the fault by changing the cable ports, combiner, or TRX.
Downlink weak coverage
The signal loss on the downlink of the TRX is large.
Move an MS to a place near the TRX to measure the actual power of the TRX. Check whether the downlink level of the TRX is low. If the downlink level of the TRX is low, check the cable
connections between the combiner and the TRX, and cable connections in the antenna system. Then, check the level at the TRX entry and output entry of the combiner by using the power meter to locate the fault.
TRX weak coverage
l The signal loss on the uplink and downlink of the TRX is large. l The TRX coverage is
remote, which causes poor uplink quality. l The TRX coverage is
remote, which causes poor downlink quality.
l Check the cables connecting the combiner and the TRX, and cable connections in the antenna system. Ensure that the cable connections are proper and secure, and then locate the fault by changing the cable ports, combiner, or TRX. l Check whether the actual azimuth of the
antenna is the same as the antenna azimuth in design. If the antenna is omni-directional, check whether the coverage is large. Over
coverage
l The TRX has the over coverage problem. l The TRX coverage is
remote, which causes poor uplink or downlink quality.
l Check whether there are missing neighboring cells and cells whose coverage is remote. l Check whether the actual azimuth of the
antenna is the same as the antenna azimuth in design. If the antenna is omni-directional, check whether the coverage is large.
Theme Description Suggestion Link
balance (uplink problem)
l Uplink and downlink levels are unbalanced, and the downlink level is higher than the uplink level.
l The great signal loss on the uplink of the TRX results in low BTS receive level and poor quality.
l Check whether the coverage complies with the planning and whether the output power of the TRX and CDU is normal. You can adjust the uplink receive threshold and the grade of the downlink static power to balance uplink and downlink levels.
l Check the cables connecting the combiner and the TRX, and cable connections in the antenna system. Ensure that the cable connections are proper and secure, and then locate the fault by changing the cable ports, combiner, and TRX. Link
balance (downlink problem)
l Uplink and downlink levels are unbalanced, and the uplink level is higher than the downlink level. l The great signal loss
on the downlink of the TRX results in low MS receive level and poor quality.
l Check whether the coverage complies with the planning and whether the output power of the TRX and CDU is normal. You can adjust the uplink receive threshold and the level of the downlink static power to balance uplink and downlink levels.
l Move an MS to a place near the TRX to check whether the downlink level of the TRX is low. If the downlink level of the TRX is low, check the cables connecting the combiner and the TRX and cable connections in the antenna system and check the level at the TRX entry and output entry of the combiner by using the power meter to locate the fault.
Other problems
l The performance of the receive level of the TRX is abnormal. l The number of MRs is
small.
Check whether the hardware or software of the TRX is faulty and whether only a few MRs are reported, and analyze the reason for the generation of a small number of MRs.
6.2 Process of GSM MR Analysis
This section describes the process of GSM measurement report (MR) analysis.
Figure 6-1 Process of GSM MR analysis
Table 6-5 describes each procedure shown in Figure 6-1.
Table 6-5 Process of GSM MR analysis No. Procedure Description 2 Create a GSM
performance data collection task
You need to choose Maintenance > Task Management on the Nastar client to open the Task Management window and then create a GSM performance data collection task. After the task is created, the Nastar periodically obtains the GSM performance data from the M2000 and then saves the data in files on the Nastar server.
3 Create a GSM performance data import task
You need to choose Maintenance > Task Management on the Nastar client to open the Task Management window, and then create a GSM performance data import task. After the tasks are created, the Nastar periodically imports the GSM performance data saved on the Nastar server into the database.
No. Procedure Description 4 Check the
integrity of GSM MR analysis data
You can double-click System Function > Data Query in the Analysis Task Management window on the Nastar client to open the Query Data dialog box and then check that all the required GSM MR analysis data is imported into the database. 5 Create a GSM
MR analysis task
In the Analysis Task Management window on the Nastar client, you can create a GSM MR analysis task. After the task is created, the Nastar retrieves the GSM performance data and GSM configuration data periodically from the database, analyzes the retrieved data, and then generates analysis results.
6 l Query GSM MR overview analysis results l Query GSM MR analysis results l Compare GSM MR analysis results
You can view the analysis results of the GSM MR analysis tasks that are successfully performed and compare the results generated in different time segments.
7 Export GSM MR overview analysis reports
You can enable the Nastar client to export GSM MR analysis results as report files.