3G to 2G cell reselection in idle mode

[foufou007]

Dear experts,
I am experiencing a very weird behavior on our network. I have an iphone 4s and a Huawei android, I am in a very good 3G coverage area very close to the site. The iphone 4s keep going to 2G in idle mode every once in a while, the android does i but not that often. If I wanna quantify it, I would say the iphone 4s goes to edge 50% of the time but the android about 5%.
Any explanation?
Thanks

[ak_rf]

Hi,
We are also having similar problems with various phones in the Network. Did you manage to get any solution ?
Thanks

[a19997104]

what network do you have? huawei ?

[aluruwaichi@yahoo.com]

-->this problem seems to be specific to smart phones? or even other normal 3g phones? check if the iphone is transmitting with very high power to the RBS.It is very possible to miss it out.

[chronix_ray]

This is maybe due to parameter issue within what venndor.

[evertonESF]

Hi,

The some case, parameters for Selection and Reselection, the triggers are too near, for eg.: Qqualmin, IdleSintrasearch, SsearchRat.

[Handover24]

Issue solved Guys PLEASE ADD REPUTATION :-) Huawei has maden a mistake...check those parameters :
THRUTRANHIGH
THRUTRANLOW
default value is 20 on Hedex...but this is not OK because it means that if the LTE UE ( only UE read this SI2 quater message ) reselect UTRAN from Geran only if UTRAN RSCP is at 60 dBm...too high...puttong this value to 5 this issue has been solved

	If the measured RSCP value of one or more neighboring UTRAN cells is higher than the value of this parameter, the MS is allowed to reselect a neighboring cell in UTRAN whose priority is higher than the GERAN priority. The values of this parameter correspond to the following decibel values: 0: 0 dB, 1: 2 dB, 2: 4 dB, 3: 6 dB, ..., 30: 60 dB, 31: 62 dB.

If the receive levels of the serving cell and all neighboring GSM cells are lower than "Low GSM Threshold Based on Priority", and if the measured RSCP value of one or more neighboring UTRAN cells is higher than the value of this parameter, the MS is allowed to reselect a neighboring cell in UTRAN whose priority is lower than the GERAN priority. The values of this parameter correspond to the following decibel values: 0: 0 dB, 1: 2 dB, 2: 4 dB, 3: 6 dB, ..., 30: 60 dB, 31: 62 dB.

Release 8	19	15	64-QAM	MIMO	.82	35.3
Release 8	20	15	64-QAM	MIMO	.98	42.2
Release 8	21	15	16-QAM	Dual-Cell	.81	23.4
Release 8	22	15	16-QAM	Dual-Cell	.97	28.0
Release 8	23	15	64-QAM	Dual-Cell	.82	35.3
Release 8	24	15	64-QAM	Dual-Cell	.98	42.2
Release 9	25	15	16-QAM	Dual-Cell + MIMO	.81	46.7
Release 9	26	15	16-QAM	Dual-Cell + MIMO	.97	55.9
Release 9	27	15	64-QAM	Dual-Cell + MIMO	.82	70.6
Release 9	28	15	64-QAM	Dual-Cell + MIMO	.98	84.4
Release 10	29	15	64-QAM	Triple-Cell	.98	63.3
Release 10	30	15	64-QAM	Triple-Cell + MIMO	.98	126.6
Release 10	31	15	64-QAM	Quad-Cell	.98	84.4
Release 10	32	15	64-QAM	Quad-Cell + MIMO	.98	168.8
Release 11	33	15	64-QAM	Hexa-Cell	.98	126.6
Release 11	34	15	64-QAM	Hexa-Cell + MIMO	.98	253.2
Release 11	35	15	64-QAM	Octa-Cell	.98	168.8
Release 11	36	15	64-QAM	Octa-Cell + MIMO	.98	337.5

if then your net is ok....add me reputation :-) UEs which could be affected are :

[giegala]

Reputation added. It is exactly the problem. We had to switch off 2G- LTE reselection support .

[fahmi]

Dear Hnadover24,

Could you please explain "the LTE UE ( only UE read this SI2 quater message ) reselect UTRAN from Geran only if UTRAN RSCP is at 60 dBm" because the default value 20 correspond to 40 db !!
Also does putting these parameters to 5 push the CS traffic from 2G to 3G ??

BR,
Fahmi

[Handover24]

Fahmi I think there is a great mistake on Huawei Documents. Putting 5 it means -110-2*5 so reselection on UTRAN will be done on -100.
We were having a lot on complaints....solved changed this parameters....we found them on SI2quater message.
If you put that to 20...reselection will be done at 60=110-2*20.
Best regards.