Section: A.21 Use case of UE power headroom
Content: E-UTRAN UE power headroom measurement is important for analyzing UE power distribution, to learn whether the uplink signal strength can be increased or not. So it is very useful to do trouble shooting of coverage hole and coverage balance for uplink. It is also used to evaluate the power control performance and increase UE power headroom as possible with QoS is guaranteed for the purpose of energy saving. These questions are determined by the ratio of the number of larger or less than threshold to the total number of it and the threshold is configurable. According to network optimization experience, the granularity of measurement 1dB is enough to do trouble shooting of coverage hole and evaluation of power control.