Methods to improve the reliability of test results for wireless network quality assessment

After several years of rapid development, the two major mobile communications operators in the network size, the number of users, business income has been faster growth. With the intensification of market competition, the quality of mobile communication network will become a key factor to determine the competitiveness of operators, and it is a powerful guarantee to further develop the users and reduce the user's off-grid rate, so improving the network quality has become the core work of the operator's construction and maintenance work. The evaluation of the quality of the mobile communication network is accomplished by analyzing the OMC traffic statistic data and conducting the wireless network quality evaluation test. The quality evaluation test of wireless network is to test the user's perception index by simulating user's behavior, not only to understand the user's real feeling of the network quality, but also to compare and evaluate the field test results of other mobile operators, and to evaluate the network comprehensively from the angle of user experience. In view of the advantages of wireless network quality assessment test in these aspects, the test results play a leading role in the quality evaluation of mobile communication networks.

The reliability of the test results of wireless network quality assessment reflects the test results, reflects the degree of the actual level of network quality, the test results with high reliability can reflect the user's feeling of network quality and the actual level of network quality. Comparatively speaking, the test results with low reliability can not find out the actual problems in the network, and can not reflect the quality level of the network, even some erroneous evaluation results may bring serious negative effects in determining the direction of work in the next stage. Because the evaluation test results have a direct impact on the evaluation of network maintenance and construction work of the operators in various provinces and cities, it plays an important role in the decision-making process of establishing the network dimension work goal, so it is very important to improve the reliability of the evaluation test results.

In this paper, the factors influencing the reliability of the test results are analyzed, and the suggestions for enhancing the credibility are put forward.

2. Factors influencing the reliability of test results

At present, the comparison of the commonly used wireless network quality assessment test methods are DT test (drivingtest, road test) and CQT test (callqualitytest, that is, call test). In the area of convenient vehicle access, the main use of DT test method, for not convenient for vehicles to pass the coverage area, such as indoor, building dense area, etc., mainly using CQT fixed-point testing methods. The evaluation test mainly uses the network quality: coverage rate, switching ratio, drop rate, call quality and other indicators to evaluate. Below we will make a concrete analysis of the factors that affect the reliability of the evaluation test.

2.1 Test Phone

Testing the new and old levels of the phone and receiving performance has a significant impact on the test results. As a result of the daily network test work more, test the use of mobile phone is high, and in the use of the process will inevitably bump, therefore, in the use of a certain period of time, the test of the performance of the mobile phone transceiver will appear to varying degrees of decline. Under the same test conditions, the test results for the use of the new mobile phone and the old one are likely to differ significantly, which will result in a different assessment if the assessment requirements are severe. When the DT road test, testing the position of the mobile phone will also have a certain impact on the test results, if the test car personnel, excessive, mobile phone antenna is blocked, its transceiver performance will be significantly reduced, will affect the accuracy of the test results. In addition, some models of the test phone in the low-power state of work, there will be continuous access failure phenomenon, if the problem can not be found in time, will have a serious impact on the network rate index.

2.2 Base Station working status

The prerequisite for the evaluation test is that all base stations in the test area are in normal working condition. When the base station works abnormally, it will be unable to call, switch abnormal phenomena, and even the adjacent base station signal will be adversely affected. Moreover, as the number of sampling points is significantly less than OMC traffic statistics, the effect of a base station on the overall test results may be several times or even dozens of times times greater than that of OMC traffic statistics, thus seriously affecting the reliability of the evaluation test results.

2.3 Test Time

The channel load of the base station of the same base station will fluctuate at different time of every day, and the whole network will also show the daily average traffic from Monday to Friday is higher than the Saturday and Sunday trend. When the channel load is different in the base station, the probability of the access failure is also different when the channel load is in the coverage range, when the traffic congestion is higher, the access failure rate will increase obviously. Therefore, if the test time is not strictly restricted when the evaluation test is carried out, it is possible to obtain an unreal access performance evaluation result.

2.4 Test Range

The network quality of different administrative regions in the city is different, if the DT test route can not be taken into account in all administrative areas, there will be a sweeping possibility, the credibility of the evaluation results are not high. Similarly, a building of different floors, floors, different positions of the coverage signal status is different, the CQT test if not as far as possible to include these positions, you may get inaccurate test results.

2.5 test methods

The test method determines the number of sampling points, and the number of sampling points determines the accuracy of the test results. When the number of sampling points is small, the probability of the test results is large, the reliability of the test results is not high, and when the number of sampling points is sufficient, the reliability of the evaluation test results is higher. In particular, access failure, drop words and other unusual events, may not meet in a short period of time, once the event occurs, the calculated ratio will be very large, which is also the network test to get the rate of access, drop rate indicators and OMC traffic statistics obtained by the same index values have a big difference in the reasons.