Voice in 3G

[Moon]

Hi Expert,

Could you please share your expertise on how to increase AMR traffic in 3G,
We are using 900 MHz for 2G & 2100 Mhz for 3G. the 3G AMR traffic is very less compared to 2G (About 10%)

Thanks

[twenty8]

Hi,
This is alot to do with operator strategy. The things you can do is .

1. See how many 3G capable UE is being used in the market.
2. Whether the operators has allowed 3G usage for the current GSM subs in their HLR profile.
3. Camping mode strategy , ie. Check QSEARCHI parameter in GSM as well as FddQmin.

[Moon]

Hi,

thanks for your reply,
regarding the % of 3G UE its assumed to be 50%,
Cell reselection parameters are already tuned to prioritize 3G layer, but the 3G voice traffic is still very low

[twenty8]

Is the operator recently rolled out 3G ? How was the marketing strategy to move the 2G users to 3G , ie. was it automatically or did the 2G subs have to apply for 3G access ? At least , if you have a 2G sim try to lock on 3G and see what error you get.

[Moon]

the 3G is a mature network & all SIM card are now 3G; also the number of 3G sites is almost same as 2G. what should be the max voice traffic that we can reach in a 3G sites (2/2/2 or 3/3/3)

[twenty8]

well you can then check the ratio between 2G erlang to 3G erlang in the BH in a particular cell to see the difference. The pole capacity for a 3G cell is about 60 voice calls.

I've attached a good document by Qualcomm, that explains these capacity limitations.

---->>>>>>>>>>>>>>>>>----------------
Pls give thanks & rep.

1 Introduction..................................................................................................3
2 Release-99 Cell Capacity............................................................................4
2.1 Uplink Capacity 5
2.1.1 Voice Capacity 6
2.1.2 Circuit Switched Data Capacity 6
2.1.3 Packet Switched Data Capacity 7
2.2 Downlink Capacity 8
2.2.1 Voice Capacity 9
2.2.2 Circuit Switched Data Capacity 10
2.2.3 Packet Switched Data Capacity 11
2.3 Mixed Traffic Capacity 12
3 Release 5 HSDPA Capacity ......................................................................14
3.1 HSDPA Cell Throughput 15
3.2 Average Cell Throughput 17
3.3 Average Cell Throughput vs. Voice Load 18
4 Other Capacity Issues...............................................................................18
4.1 Coverage 19
4.2 Soft Handover and Cell Capacity 19
4.3 OVSF Code Limitation 20
5 Conclusion.................................................................................................20

[Moon]

thanks for the good doc,
for 2G traffic in some cells we can reach 120 Erlang in BH while 3G cells is having max 20 Erlang in BH (& some 3G cells are having 2 Erlang in BH);
For the parameters we have Qqualmin =-18; SsearchRAT=2 dB; EcNo threshold for HO = -12dB (this parameter was decreased to -16dB but the traffic/cell in BH was increased by few Erlang only). any other parameters that can be tuned?

[RFDude_PMA]

Hi

Can you tell us the cell reselection parameters for example in E/// we have in the rllop ( isolev) in the rlsup (fddmin, fddqoff, qsc,qsi,fddmrr and sprio) and rlump (umfi in idle or active)

Do you have E/// or huawei?

[twenty8]

those are 3G > 2G reselection parameters, you need to look at 2G > 3g reselection parameters... see QsearchI, FddQmin , FddQoffset . But I would also check with CN engineer on the HLR subscription for the users as well.

[kilisuci_kdr]

Hi, what about the physical coverage?
Is it the same, are you using single band antenna or separate?
Just need to check the orientation or tilting also to make sure it has same coverge.