TA in LTE

[mohdkkl]

Hello Experts,

Can anyone tell me about TA in LTE.

eNodeB measures the required timing advance based on received signal arriving time.
eNodeB to adjust the transmission time.

It is 78m from UE to eNodeB if UE is near at the enodeB?
Or anything else…TA1 is 156m?

Please update me which is one correct.

Admin note: this post was updated with image below.

[AbdurRehman87]

In LTE 1 TA = 78 m.

[Neel_Soni]

Yes, correct.

[AbdurRehman87]

To avoid handling of so many TA counters vendors start binning them and they create bins or pdf counters.
In Huawei LTE there 11 or 12 bins with each bin specifying a range of TA.

[mohdkkl]

It will be vary depending on vendors?
If 2 TA, then it will be 156m?

[AbdurRehman87]

Yes, but they group them normally in unequal bins.

Not exactly but something like this:
78-234
234-512
512-1024

[Ali.raza]

For Huawei:

L.RA.TA.UE.Index0 - 0~156m
L.RA.TA.UE.Index1 - 156~234m
L.RA.TA.UE.Index2 - 234~546m
L.RA.TA.UE.Index3 - 546m~1014m
L.RA.TA.UE.Index4 - 1014m~1950m
…

[jitendra.vishwakarma]

Can anyone share counter to get TA in Ericsson?

[Mustafa_Rawat]

pmTimingAdvance
This is an EVENT Counter.

[jitendra.vishwakarma]

It required separate server?
Because in my NW its not enabled.

[Mustafa_Rawat]

These counters cannot be fetched by OSS unless ENIQ-Events is activated (Additional Server).

TA counter relies on Baseband-generated event – INTERNAL_PER_RADIO_UE_MEASUREMENT_TA, via feature Enhanced Cell ID in Traces

Activate optional feature license: “Enhanced Cell ID in Traces” on LTE Sites. This feature makes it possible to group collect statistics on TA values.

Then you can see them in LTE Cell Trace on Xeus or any other tool you may have for parsing the traces.

[Vishal_Thakkar]

Hi Can you help with CTR parser ?

[Pirm]

Dears Experts.
What’s the value of TA counter, please?
Counters: pmTaInit2Distr or pmTaInit2Dist
For example for TA=0. Does it mean, 428m ?
Vendor is Ericsson, L20.

[ran_core_consultant]

TA0 means no adjustment needed.

4G LTE Timing Advance Distance Calculator | 5G-Tools.com

[qudratullah_ehsan]

Hello,

Can anyone tell me, that what is cell radius in LTE (ZTE) I need this counter for the coverage map.

Thanks

[Usman_Ghani]

[Mohammad_Din_Ashna]

Hello Experts,

Can anyone tell me about TA in LTE.
TA1 is 0----78m or TA1 is 0-----156m
And please explain TA1…TA6,TA7 calculation formula.

[Serg]

hi, maybe there you will find what you need

Parameter Timing Advance (TA)

Introduction The Timing Advance parameter is very important in many applications and procedures of the GSM system. [image] Let us understand what it is today, and know its main uses. What is Parameter Timing Advance (TA) in GSM? The Timing Advance is a parameter that allows the GSM BTS to control the signal delays in their communication with the mobile. More specifically, is calculated by the delay of information bits in Data Access Burst received by BTS. [image] Recalling a little: GSM …

[Mohammad_Din_Ashna]

I saw that but my question Please, how is TA value calculated in LTE.

[MrBeam]

• When a UE wants to initiate communication, it sends a Random Access Channel (RACH) preamble to the eNodeB.

• The eNodeB responds with a TA command, which tells the UE how much to adjust its transmission timing to compensate for the propagation delay.

• The TA value is expressed in units, where one TA unit equals 0.52 microseconds (µs), corresponding to a distance of approximately 78 meters between the UE and the eNodeB.

• The distance between the UE and the eNodeB can be calculated by multiplying the TA value by 78 meters.

Why 0.52 microseconds (µs)?

TA (Timing Advance) Step Duration of 0.52 microseconds is standardized by 3GPP in TS 36.211. Specifically:

• 3GPP TS 36.211 is titled “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation”, which outlines the LTE physical layer specifications.
• The TA step duration is defined in Section 4.2 of this document, specifying the step as 16 Ts (where Ts is the basic time unit in LTE, equal to 1/30,720,000 seconds).

Given Ts is about 0.032552083 microseconds, 16 Ts equates to 0.52 microseconds, which corresponds to a distance of 78 meters for each TA step in terms of round-trip propagation. This standard ensures timing adjustments are consistent across LTE networks.

Why 78 Meters?

• Round-trip time (RTT) is the time taken for a signal to travel from the eNodeB to the UE and back.

• The TA adjusts for the round-trip distance between the device and the cell tower. Since radio signals travel to and from the tower, each TA step represents half of that journey.

• Given the speed of light (300,000 km/s), a signal can travel 156 meters round-trip in 0.52 microseconds. Dividing this by 2 gives 78 meters for the one-way distance.