Minimization of drive tests solution in 3GPP

Providing network coverage and quality of service (QoS) is an important task of a cellular network operator. This is because cellular spectrum is normally licensed under certain coverage obligations, and operators need to be competitive in market. To improve their networks, operators often send engineers in the field to collect radio measurements, to discover problems such as coverage holes in the network, and to determine whether certain parameter tuning is needed. However, such conventional "drive tests" require large Operation Expenditure (OPEX), while the collected measurements can only give limited snap shots of the entire network. In their Release 10 (Rel-10) specification, 3GPP studied and specified solutions to reduce this OPEX for drive tests, under the work item named ¿Minimization of Drive Tests (MDT)." The solution utilizes the user (customer) equipments (UEs) to collect field measurements, including radio measurements and location information. This article describes in details the solution adopted in 3GPP MDT; how they were developed and intended to be used.