Availability in Cellular Networks: Supporting Coverage Planning With User Equipment Measurement Data
Lahti, Antti Matti Ilmari (2017)
2017
Tietotekniikka
Tieto- ja sähkötekniikan tiedekunta - Faculty of Computing and Electrical Engineering
This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited.
Hyväksymispäivämäärä
2017-04-05
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-201703151176
https://urn.fi/URN:NBN:fi:tty-201703151176
Tiivistelmä
Customers are expecting high-performance mobile services to be available without chronological or geographical restrictions. The coverage of the mobile network is typically calculated with aid of propagation models that are calibrated with field measurements. The uncertainty associated with the propagation models, the challenges presented with customer complaints, the costs of field measurements, and the authorities’ coverage obligations are the main reasons for mobile operators’ interests to search for new methods to model and measure the mobile networks.
3GPP’s Minimization of Drive Tests (MDT) framework provides a possibility to utilize ordinary User Equipment (UE) for conducting the measurements. The devices that are connected to the mobile network observe the signal environment constantly and send measurements of these observations to the base stations via Radio Resource Control (RRC) connection. This thesis introduces the most important features of the MDT, which are then assessed for validating customer complaints. In Sonera mobile network, MDT-based measurement reporting is currently using a network-based positioning, which was expected to involve inaccuracy. Therefore, the evaluation of the positioning became a central part of this thesis.
A system that visually represents MDT-based measurement data, gathered from Sonera’s mobile network, was utilized comprehensively during the work. For evaluating the geolocation accuracy, drive tests were conducted in different parts of Finland. The results showed that the geolocation accuracy is the most important factor to be considered when utilizing the MDT-based measurement data in coverage modeling. For UMTS system, it was concluded that during the time of the assessment, a particular location of interest should be examined with approximately 400-meter radius in suburban and urban areas.
The heat maps consisting of the MDT-based UE measurement reports were used to validate a sample of 28 customer complaints. Tests showed that the heat maps are correlating rather well with the field measurements. In the last part, it was concluded that the heat maps were able to validate 68 % of the feedback sample. The work showed that collected mass of measurement data could be utilized as a preliminary validation method for the customer complaints. In its entirety, the MDT-based measurement data provides a new approach to the constant improvement of customer experience and quality in the mobile networks.
3GPP’s Minimization of Drive Tests (MDT) framework provides a possibility to utilize ordinary User Equipment (UE) for conducting the measurements. The devices that are connected to the mobile network observe the signal environment constantly and send measurements of these observations to the base stations via Radio Resource Control (RRC) connection. This thesis introduces the most important features of the MDT, which are then assessed for validating customer complaints. In Sonera mobile network, MDT-based measurement reporting is currently using a network-based positioning, which was expected to involve inaccuracy. Therefore, the evaluation of the positioning became a central part of this thesis.
A system that visually represents MDT-based measurement data, gathered from Sonera’s mobile network, was utilized comprehensively during the work. For evaluating the geolocation accuracy, drive tests were conducted in different parts of Finland. The results showed that the geolocation accuracy is the most important factor to be considered when utilizing the MDT-based measurement data in coverage modeling. For UMTS system, it was concluded that during the time of the assessment, a particular location of interest should be examined with approximately 400-meter radius in suburban and urban areas.
The heat maps consisting of the MDT-based UE measurement reports were used to validate a sample of 28 customer complaints. Tests showed that the heat maps are correlating rather well with the field measurements. In the last part, it was concluded that the heat maps were able to validate 68 % of the feedback sample. The work showed that collected mass of measurement data could be utilized as a preliminary validation method for the customer complaints. In its entirety, the MDT-based measurement data provides a new approach to the constant improvement of customer experience and quality in the mobile networks.