Shift Traffic from UMTS to GSM (3G Traffic to 2G)?

Mobility
,
1

Hi Experts,
I know this could sound kind of generic, but I needed expert advice. :wink:
What’s the best practice to be done in order to shift traffic from U900 to G900 (mainly CS traffic)?
The site is alone site.
Vendor is Huawei

2

Traffic aware mobility? (Not sure if available in 3G).
When mobile triggers Voice call, network force handover.

1 Like
3

To shift only CS traffic, you can increase 2D/2F measurement, handover threshold of CS to very high, for e.g. -50 dBm.
UE in CS connected will be easy to iRAT HO to GSM.

1 Like
4

Changing 2d threshold would lead to shift of all type of Traffic.
So you can give service specific offset, although it is an RNC level parameter.
Here you can give service negative offset to PS rab, and can set 2d EcNo at level of -4 dB at cell level, so all CS traffic would move to 2G, but data PS traffic would remain in 3G.

1 Like
5

Aare there any feature that load-oriented?

6

Features not load oriented.

1 Like
7

I am referring to something like LDR or OLC, but for 3G-2G.

8

2D/2F threshold have different value for amr, ps r99, hspa. Just increase 2d2f of amr service. And parameters have rnc-level and cell-levell, to shift for 1 site, just change cell-level parameter.

1 Like
9

Increase 2d and 2f of AMR service only.

1 Like
10

1a,1b,1c,1e,1f … :slight_smile:
Very old words for 3G events… How technology vanish within 5 years!
Can’t believe.

1 Like
11

Those who work with 3G know it is a pain compared to LTE.
LTE is easier the 3G (if compared with that technology).

1 Like
12

Inter-RATs is always a headache anyways, but yeah you are right.

And thank you all folks, I got the idea! :wink:

13

Hello guys, some suggestions:

Due to traffic there are many options available, i.e. Directed Re-try, load based HO, relax compress mode and IRAT triggering threshold etc.

Further idle mode parameters can be tuned on 3G & 2G side.

You can also play with parameters like FDDQMIN and QSEARCH (I, C, P). These are the Idle mode regulation parameters which can be set from the 2G side. By tuning of this parameters you can make reselection procedure from 2G to 3G more complicated. So they can help you to keep more traffic at the 2G side.

But also check if in your network MS can go from 2G to 3G only by resection or also by handover (parameters - BET3GHOEN, OutSysLoadHoEn).

To shift traffic just during specific hours then load based handover is fine. OR you may schedule script in OSS for auto revision just mention specific time.

From 3G side you can also push more traffic to 2G by changing the IDLE mode parameters (Qqualmin, Qrxlevmin, SsearchRat, be careful - do not create ping pong). As other option to be more aggressive in IRAT HO thresholds from 3G to 2G - groups UCELLINTERRATHOCOV and UCELLINTERRATHONCOV). There are also load balancing algorithms for the traffic redistribution - check LDR and DRD if you 3G network has high traffic load that can help.

You can play with LDR actions in 3G to offload to 2G. LDR has 5 steps to offload the 3G traffic… CS INTERFREQ, PS INTERFREQ, CS IRAT, and PS IRAT.

LDR is more safe as a technique to offload the traffic since it will check the 2G condition before shifting the bearer.

And finally, in case you want the opposite, take a look here: Best way to move traffic from 2G->3G

Hope that helps.