4 Main concept and requirements

37.3203GPPOverall descriptionRadio measurement collection for Minimization of Drive Tests (MDT)Release 17Stage 2TS

4.1 General

The general principles and requirements guiding the definition of functions for Minimization of drive tests are the following:

1. MDT mode
There are two modes for the MDT measurements: Logged MDT and Immediate MDT. There are also cases of measurement collection not specified as either immediate or logged MDT, such as Accessibility measurements.

2. UE measurement configuration
It is possible to configure MDT measurements for the UE logging purpose independently from the network configurations for normal RRM purposes. However, in most cases, the availability of measurement results is conditionally dependent on the UE RRM configuration.

3. UE measurement collection and reporting
UE MDT measurement logs consist of multiple events and measurements taken over time. The time interval for measurement collection and reporting is decoupled in order to limit the impact on the UE battery consumption and network signalling load.

4. Geographical scope of measurement logging
It is possible to configure the geographical area where the defined set of measurements shall be collected.

5. Location information
The measurements shall be linked to available location information and/or other information or measurements that can be used to derive location information.

6. Time information
The measurements in measurement logs shall be linked to a time stamp.

7. Sensor information
The measurements can be linked to available sensor information that can be used to derive UE orientation in a global coordinate system, the uncompensated barometric pressure and the UE speed.

8. UE capability information
The network may use UE capabilities to select terminals for MDT measurements.

9. Dependency on SON
The solutions for MDT are able to work independently from SON support in the network. Relation between measurements/solution for MDT and UE side SON functions shall be established in a way that re-use of functions is achieved where possible.

10. Dependency on TRACE
The subscriber/cell trace functionality is reused and extended to support MDT. If the MDT is initiated towards a specific UE (e.g. based on IMSI, IMEI-SV, etc.), the signalling based trace procedure is used, otherwise the management based trace procedure (or cell traffic trace procedure) is used. Network signalling and overall control of MDT is described in TS 32.422 [6].

The solutions for MDT shall take into account the following constraints:

1. UE measurements
The UE measurement logging mechanism is an optional feature. In order to limit the impact on UE power consumption and processing, the UE measurement logging should as much as possible rely on the measurements that are available in the UE according to radio resource management enforced by the access network.

2. Location information
The availability of location information is subject to UE capability and/or UE implementation. Solutions requiring location information shall take into account power consumption of the UE due to the need to run its positioning components.