- This topic has 6 replies, 1 voice, and was last updated 12 years, 5 months ago by eng.
5th September 2008 at 05:12 #53794SMGuest
I would like to know that the Half Rate will effect to the QoS(such as increase the call drop) or not?
Thank you very much for your time.
BRs,5th September 2008 at 06:50 #53795pixGuest
normally, it shouldn’t have any effect on call drop rate…
pix5th September 2008 at 08:17 #53796SMGuest
That’s mean it doesn’t have any effect to any QoS? (except the vioce quality should be more poor than the FR,right?)
This result is from the theory or in the actual network which is using the HR?
We are using Alcatel and Motorola BSS.
BRs,5th September 2008 at 16:26 #53797pixGuest
it’s from theory… in reality
1. your BSS is carrying more subscribers –> more load, more signalling –> more risk of failures
2. the HR codec is a little less protected than the enhanced full rate, so it’s *slightly* more sensitive to interferences. But it’s noticeable only if the frequency planning is bad in many areas.
to fight problem 1 –> contact your vendor so they can fix their machines
to fight problem 2 –> activate AMR HR, which provides more resistant codecs than the legacy HR.7th September 2008 at 14:17 #53798rf fanGuest
I think that signaling channels don’t depend of used codec, so it has not any effect over call drop.7th September 2008 at 17:03 #53799pixGuest
hi rf fan,
the fact is:
if you put twice more calls on a cell, it means the BSC has to double its “signalling” processing. Meaning it has to monitor twice more calls than before.
so yes, half rate is putting more load on the system, from a signalling point of view (i’m not talking about Air/Abis signalling ! i’m talking about BSC processing load & also BTS load). But perhaps the BTS/BSC can support this load without any problem. Or perhaps it can’t. I’ve heard stories about some systems that couldn’t (in the past… –> i don’t know what is the situation right now)
pix15th September 2008 at 10:35 #53800engGuest
I have noticed that in HR mode, SQI is more affected, the fact that the maximum SQI in HR mode is only 17. And fast SQI degradation is observed especially in areas where RxLevel is not good. Yes, if there is interference, subscriber experience is not that good, which would relate to bad RxQuality.