RSCP in idle mode in 3G is lower than conected mode

[moj900]

Dears
when we did 3G drivtest and got report tems logfile form ACTIX , RSCP in Idle mode always lower than connected mode,
would you please guide me , why RSCP in Idle mode is lower than connected mode !

[redendo]

may be that the cells in idle mode in which the UE is camped on are different than those in connected mode, also the power control algorithm which is mandatory and much fast in 3G (1500 times per second) to avoid cell overloading.

Hope it can help

[Mdaf]

may be that the cells in idle mode in which the UE is camped on are different than those in connected mode, also the power control algorithm which is mandatory and much fast in 3G (1500 times per second) to avoid cell overloading.

Hope it can help
RSCP is not power controlled.

[Boraa]

what is about the EcNo still the same ?

[Paletero]

In my experience as drivetest is always that way. In Idle mode RSCP is lower that in connected mode. That's beacause with no resources allocated, a UE will measure as low as it can.

[srilasitha]

In my experience as drivetest is always that way. In Idle mode RSCP is lower that in connected mode. That's beacause with no resources allocated, a UE will measure as low as it can.

I have seen the same thing. but the difference is quite small

[Muhammad Imran Rafique]

Hi All,
The difference is due to treselection(idle mode) & timetotrigger1a
2 sec & 200ms:

In idle mode we delay cell reselection till 2sec, however same thing is done in just 200 or 100 ms in connected mode. RSCP is not power controlled or either channelized, so if serving cell is same there cant be any RSCP difference.

I am sure the discussion is on cluster level, where you will find big difference in serving cells (idle & connected mode)

BR//
Imran

[Philippe]

There should not be difference between CPICH RSCP in idle and connected mode as CPICH power is not power controlled.
I guess what you mean here is that if you drive far from the cell the worst RSCP you will measure in connected mode is not as low than the one you will measure in idle.
I think this is normal: in connected mode, the call will drop due to limitation of uplink link budget or degradation of Ec/Io required to maintain connection. While in idle mode, you cill still be able to measure a given level of CPICH RSCP.

[rumy]

Hi mojo,

PLease make it clear for us by how much would it mean lower (0.5/1/2 dB?), I guess you took the PDF for CPICH and compared it at cluster level...

I guess COnnected would always be better thinking that you would gain from SHO; you would choose much faster a better cell than in Idle (usually 1sec treselect)

[Muhammad Imran Rafique]

Hi All,

As I mentioned earlier, its proven fact the only difference is "time to trigger1a" & "treselection" (200ms & 2 sec).
there is no power control and no dependency of PCIPCH channel on any other condition except this one.

BR//
Imran

[ouedraogo2d]

Hi All,
The problem may be one of the following:
1) The cell used in Idle mode may not be the same than in connected mode
2) treselection (Idle mode) is 2 sec and time to trigger 1a (conne"cted mode) is 200 to 100 ms

[rnpopt]

Hi All,
The problem may be one of the following:
1) The cell used in Idle mode may not be the same than in connected mode
2) treselection (Idle mode) is 2 sec and time to trigger 1a (conne"cted mode) is 200 to 100 ms

Yes.Correct, this should be the cause.

[Amr Harby]

One important factor to be taking into consideration is the power control sittings, the max power for the DCH channel ...xxpwrmax because it's value is relative to CPICH power so if it's for example sit to 30 this means it can reach up to 3 db more than the CPICH value and you may experience increase in the RSCPof the connected mode with the same margin

[Muhammad Imran Rafique]

Hi Amr,

Don't agree, in any case reported RSCP is of CPICH power either its dedicated or idle.
increasing power for any particular SF cant give more power in CPICH channel.

Thanks,
Imran

[Amr Harby]

Hi Imran,

As far as I know, mobile during the dedicated mode is measuring the DCH channel for the cells in the active set , and the CPICH for the neighbours cells .... this is my understanding .... any way if you can confirm the information that the mobile will report the CPICH channel even during the dedicated mode it will be great, I will try to confirm from my side as well..

Second point that the impact you are describing of delaying the cell re selection relative to the active set update timer is very minimal as it's taking place only at cell borders .... is that means that the dedicated measurements should be equal to the idle in all the cell footprint where the cell is the only server in the sctive set and no cell change is to take place ... I doubt that based on the practical field experience