RT, LTE terminal how to judge downward step & amp; & Upward step (with a focus on the upward step)

CodePudding user response:

For downlink said, UE will keep for testing, a detection threshold, Qin, Qout, as well as the corresponding UE constants T311 timer, T310, to determine whether downlink synchronization out-of-step,
TA is used to do? Mainly used for the uplink synchronization of measurement, downlink synchronization, but cannot guarantee on the uplink is synchronous, TDD is relatively better, up and down in a frequency band, TDD FDD is has belong to different frequencies,
TA, the length of the timer is configured in the background, the base station may be a survey of uplink channel of TA, if found UE side and the side of the base station have deviation, will be to adjust X - Ts, base station side will maintain this timer, if it is found that the timer timeout, will release the UE uplink resources,