A.3 Use case of UE timing advance

32.4053GPPPerformance Management (PM)Performance measurementsRelease 17Telecommunication managementTSUniversal Terrestrial Radio Access Network (UTRAN)

UE timing advance measurement is useful to analyze distance distribution between UE and serving Base Station and do trouble shooting of extending coverage and blind coverage spot together with other measurements, such as P-CCPCH RSCP, AOA etc measurements. The probability of extending coverage and blind coverage should be analyzed by the ratio of the number of TIMING_ADVANCE that is larger than or equal to threshold to the total number of it. Threshold is configurable according to the cases to be analyzed, cases includes dense urban area macro cell suburban area macro cell and rural area cell.

For LCR TDD mode, propagation distance of 1 chip is nearly 234m. since urban cell radius nearly 500m, and suburban cell radius is nearly 1000m, and rural cell radius is nearly 2000m, according to optimization experience, minimize granularity of TIMING_ADVANCE is 0.5chip is enough to analyze distance distribution for near base station, namely TIMING_ADVANCE is less than 4 chips. For TIMING_ADVANCE is large than 4 chips and less than 32 chips, the corresponding propagation distance is from 936m to 7488m, the granularity is 1 chip is enough to do trouble shooting of extending coverage. For TIMING_ADVANCE is large than 32 chips, how far accurately can not be learned from it because of the complexity of wireless propagation, it is enough that extending coverage is learned from it in this case.

So it is necessary to define UE timing advance measurement with small granularity.