KPIs

Hello,

Timing Advance
TA(Timing Advance), is an advance time, for UE to send out UL frame before the start of thecorresponding downlink radio frame at the UE, for channel sync purpose
UE will start atimer when sending Preamble for access. Upon succeed receive the response from eNodeB,UE will get the TA needed for following radio frame transmission
3GPP 36.213 (4.2.3)
defines that 1 TA = 16*Ts=16*(0.5ms/15360)=0.52μs
So 1 TA time advance maps to thedistance between
eNodeB and UE is: (300,000km/s*0.52μs)/2 = 78m Here 300,000km/s is
the spread speed of electic wave, 2 means a round trip between UE and eNodeB
So thedistance between UE and eNodeB = 78 * TA (m) Also from here the accuracy of the TA is78m
Huawei has a counter to count the TA value when receive UE Radom Access

Thanks

Hello, dear.

You can refer to the following information

Timing Advance in LTE

The eNB measures the required timing advance based on the received UE signal arrival time. It commands the UE to adjust the transmission time. This is performed on a per-need basis.

It is signaled by means of a special MAC control element; LCID = 11101.
The signaled granularity is 16 Ts. The value range for adjustment is 8 bit and related
to the current UL timing.

As Ts. = 1 / (2048 x 15000) sec = 1 / 30720000 sec the granularity is given by
0.52 μsec (corresponding to 78 m).

If UE is in-sync the timing advance is valid. Otherwise the RACH-procedure
establishes a valid timing advance. An 11-bit value (range 0,1..1282) is signaled to establish the initial offset.