Quote Originally Posted by radio_network View Post
Thanks for the above explanation.
Huawei 3g problems:

1. In some of the Sectors/NodeB Huawei, in Auto mode the phone is frequently moving to 2g even near to the sector. Is there any suggestion pl.

2. In some sectors, (using DSP CELLCHK ) uplink load seems to be zero and Noise fig is also observed -70 something diff from -67. Is there any suggestion pl.
Hi,
I think it would be better if you posted those question in new topic, as they're not linked directly to "pushing traffic to 2g" topic. Nevertheless I will try to give you some answer

1. In general, UE is deciding to move between intrafreq/interfreq/interrat based on EcNo and RSCP values. Situation you described may happen in both Idle and Connected mode - principle is the same, but different parameters govern this process.
I will assume that this happens in idle (idle, pch or fach - they're all controlled by the same parameter. Peremeters which control reselections in idle are:
UCELLSELRESEL\qRxLevMin (lets assume -114 dBm)
UCELLSELRESEL\sSearchRat (lets assume 2 dB)
There is a lot of others params which control UE behavior, but since you mention specifically moving to 2g, I have narrowed it down to those 2. So to reselect to 2g assuming values above, your signal would have to drop to -114 dBm + 2 dB = -112 dBm.

EcNo is used rather for intrafreq/interfreq reselection - I don't remember if it can be used also as criteria for interrat measurement - In my opinion event if it can - it shouldnt be used.

So to troubleshoot your case, make some measurements on your phone - see what is the signal level and quality when the phone is switched to 2g. Then troubleshoot why the level or quality is low. If switching to 2g happens in connected - check values of e2d, e2f thresholds in UCELLINTERFEQHOCOV / UCELLINTERRATHOCOV - or on appropriate objects on RNC. After checking parameters make some measurements as well to check if it's quality or level that causes the HO, and troubleshoot the problem accordingly.


2. To help with these one, you should give us some more details. Maybe the following questions will help to narrow it down:
- What's common for sectors having such problems?
- What's the site type? Stack (feeders?) distributed (no feeders, RRU and jumpers used instead?)
- What technologies and frequencies are on those sectors? Do they share feeders? antennas? any other elements?
- What happen when you tilt this sector antenna down or change the azimuth? Do the interference go down?
- Are there any obstacles in front of antennas which could reflect emitted waves?
- In case you share multiple bands/technologies: what happens when you turn down all other cells in the same sector? Do the interference go down?
- Is the interference constant in time, or do they happen and disappear?
- Can you measure the spectrum with any external equipement in this azimuth?