MDT Use Cases
There are various use cases for the operators from the perspective of MDT:
-It is one of the most important aspects of the network performance which can be directly recognized by the end-user.
-With the help of MDT, it is possible to detect the signal strength and the location of the mobile, which then could be used as a coverage indicator.
-However, the main problem is, that the signal strength between mobiles at the same location and time can differ much more than +- 6dB.
-Another problem is that it is unknown if the mobile is inside the bag or some car which leads to signal loss.
-It logged MDT is used it is not possible to know how if it is not possible to know if it was a network failure or the mobile.
-This type of problem could be solved by collecting many measurement data, which then could be merged and statistically evaluated after that.
-Another problem is that, how to get the location inside the building, it is also suggested to use a GNSS (Global Navigation Satellite System) chip as a location provider.
-There is also a need for good coverage inside big buildings like airports.
-This also requires indoor measurements, but there a GNSS chip is not usable.
-With the help of DT (Drive Testing) and a scanner as a measurement device, it is possible to collect coverage measurements in high quality.
-The problem with this is that it provides only a snapshot of that area, where the DT was executed.
-Another use case for optimizing the mobile network is mobility optimization.
-The aim is to have handover failure rates that are as small as possible.
-Handover failure can happen if the mobile and networks do not recognize that the user travels from one cell to another and then as a consequence, the user travels from one cell to another, and then as a consequence that user loses the signal from the old cell.
-Another problem could be that the load is too high and the handover takes too much time.
-In most cases, the call would be dropped.
-For network capacity planning, the operator is interested in the DL (Downlink) and UL (Uplink) throughput and data volume, e.g. to deploy an additional pico cell.
-In 3GPP (3rd Generation Partnership Project) Rel -11, the throughput and volume measurement at MDT were also addressed.
-MDT allows for measuring throughput at the RAN (Radio Access Network).
-A difference to drive tests is also that MDT uses ordinary user traffic and drive tests applications with known traffic characteristics.
-With large data blocks the results are limited by the transmission medium.
-With help of MDT it is possible to measure the amount of traffic within a cell.
-The location of the sending UE (User Equipment) is stored together with the measured data volumes.
-The sub-optional configuration of common channel parameters (random access, paging, and broadcasting channels) can degrade the network performance.
-For instance, the UE (User Equipment) monitors the paging channels, which are needed to react to the incoming calls.
-If now the information cannot be decoded, the UE is not reachable for other calls.
-The operators only find out about problems with the common channels, when they receive customer complaints.
Quality of Services (QoS) Verification
The verification of QoS is another important use case.
-It is not only the coverage that affects the user experienced QoS, but also the scheduling principle for packet type connections which is defined by the operator.
-The high degree of algorithm flexibility leads to different performance.
- It is difficult to estimate the QoS from radio measurements such as coverage, path loss, or coverage interference.
- A benefit of the MDT throughput measurement is that real user traffic is used and no additional load on the network is produced.