LTE Cell reselection issue

[Ganesh Raj]

Hi Everyone,

Cell reselecrtion to LTE from UMTS is taking longer time even though the feature FAJ 121 1474 ( Cell reselection to LTE based on priority ) is turned ON and Threshxhigh value is 4db and Qrxlevmin is 120. Can anyone suggest what could be the issue. Thanks in advance.

Regards,
Ganesh.P

[giegala]

Hi,

you have to check periodicity of SIB19 in WCDMA - UE in UMTS needs to be informed about LTE carriers and their priorities. There is no direct parameter that would tell you the value - you have to use DT tool, like Tems investigation to check setup in MIB and SB (scheduling Blocks).

If the period is long, then reselection will be delayed by the amount.

[TEMS]

@Ganesh Raj

which vendor??

[MINTO]

Hi Everyone,

Cell reselecrtion to LTE from UMTS is taking longer time even though the feature FAJ 121 1474 ( Cell reselection to LTE based on priority ) is turned ON and Threshxhigh value is 4db and Qrxlevmin is 120. Can anyone suggest what could be the issue. Thanks in advance.

Regards,
Ganesh.P

check Priority in SIB 19, also UMTS to LTE fast return feature is enabled or not if enabled check redirection order settings

[desi_larka]

Hi Ganesh

Can you specify the scenario in details please.

Some obvious questions are

(a) Is it a CSFB UE or just a PS reselection due to coverage levels of LTE vs UMTS
(b) What are the SIB 19 priorities set.
(c) I am assuming that you are doing reselection within the same PLMN.
(d) Is the UE in CELL_FACH state when you are expecting the movement to happen ? This is possible only if redirect feature is enabled.

regards

[DJ Download]

I would check first if the SIB19 is enabled in the RNC / LAC everywhere in the network, sometimes this is overlooked and not configured. Secondly check the SIB19 periodicity, if it is too long then it would delay the reselection to LTE.

[esoestemp]

Hi,
I see SIB19 configured in UCELLSIBSWITCH in our network.
However from DT I don't see it transmitted.
In MIB there is also no information about it.
It is several days DT and not a single SIB19 recorded.
Does it mean there is no reselection U->LTE or it is just random?

Thanks!

[DJ Download]

If No SIB19 is seen from the logfiles that means that there is probably something wrong with the configuration.
If this is the case cell reselection to LTE will be very difficult and most likely wont happen.

[juanpico]

TEMS

From the format of Feature (FAJ 121 1474), I believe this is E///

br/juan/rf

@Ganesh Raj

which vendor??

[Youssef]

Hello

If your settings are following recommanded vale so the reselection delay is manil due to location update procedure. Try to set same tac lac.