PDA

View Full Version : [3G] Local Cell radius Parameter



rimoucha
2010-12-11, 03:22 PM
Hello,

We have changed the local cell radius value from 29000m (which is the default value) to 4000m but we have noticed that consequently the PS call drop increased (VS.HSDPA.RAB.LOSS.RF counter),the CSSR decreased and the number of unsuccessful paging procedure has doubled. Any idea about this parameter and its impact on main KPIs?
the Vendor is Huawei.

Thank you in advance,

qaqa
2010-12-11, 04:51 PM
hello

Have you checked the iner-handover radius? make it 150m if different than that

agenov
2010-12-12, 12:49 AM
Hello,

We have changed the local cell radius value from 29000m (which is the default value) to 4000m but we have noticed that consequently the PS call drop increased (VS.HSDPA.RAB.LOSS.RF counter),the CSSR decreased and the number of unsuccessful paging procedure has doubled. Any idea about this parameter and its impact on main KPIs?
the Vendor is Huawei.

Thank you in advance,

Why you changed it?

rimoucha
2010-12-12, 05:55 AM
Hello,

Thanks.

@qaqa: what's the "Local cell inner handover radius" ? is it related to the "local cell radius"?Could you please give us more details about it? I'll check this parameteron Monday...

@agenov:we have changed it because the 29000m seems too high it exceeds the 3G cell radius especially in urban areas.


BR

agenov
2010-12-12, 06:26 AM
Hello,

Thanks.

@qaqa: what's the "Local cell inner handover radius" ? is it related to the "local cell radius"?Could you please give us more details about it? I'll check this parameteron Monday...

@agenov:we have changed it because the 29000m seems too high it exceeds the 3G cell radius especially in urban areas.


BR

Of course it is too high but this doesn't matter. In my opinion and experience you don't have to change it.

sala70vic
2010-12-13, 12:50 AM
Hello,

We have changed the local cell radius value from 29000m (which is the default value) to 4000m but we have noticed that consequently the PS call drop increased (VS.HSDPA.RAB.LOSS.RF counter),the CSSR decreased and the number of unsuccessful paging procedure has doubled. Any idea about this parameter and its impact on main KPIs?
the Vendor is Huawei.

Thank you in advance,

Hi,

The RNC will use propogation delay to estimate the distance of the UE to the NodeB, as your KPIs were affected that means that this cell is overshoot over 4000m, so verify the cell/cluster coverage before blocking users>4000m.
thanks.
regards,

rimoucha
2010-12-13, 05:36 PM
Hello,

For information,below are Huawei definition of both parameters (Local cell radius & cell handover radius):

Cell Radius
This parameter describes the radius of a NodeB cell. Cell radius affects the demodulation of the uplink board and the configuration of the parameters related to the access part.
Physical Value Range
150 m to 180 km, with step length as 1 m
Parameter Setting
The default value is 29000, which stands for 29 km.
You can set and adjust a value for this parameter based on the network planning and network optimization result. In case the cell radius cannot be determined precisely, the set cell radius must be greater than the required cell radius. The set cell radius, however, should be properly great. Otherwise, the extra network resources are wasted and the system processing delay occurs. Based on the data provided by relevant products, the handover synchronization time increases by a maximum of 60 ms if the cell radius changes its value in increments of 3.75 km.
CAUTION:
· When using the RRU, you must set the sum of the cell radius and the fiber transmission delay as the cell radius.
· If the access board of the NodeB is configured to support multiple sectors, the maximum of the configurable cell radius is 30 km.
Impact on the Network Performance
The setting of this parameter must be the same as the result of network planning.

Cell Handover Radius

This parameter describes the cell handover radius, which can be configured on the NodeB console.
Physical Value Range0 to 18 km, with step length as 1 m.
Parameter Setting
The default value is 0. The inner radius of a cell handover radius must be at least 78.125 m, that is, 1 chip, shorter than the cell radius.
You can set and adjust a value for this parameter based on network planning and network optimization result. In case the cell handover range cannot be determined precisely, the value set for the cell handover radius must be smaller than the minimum cell handover radius required for network planning. The set value, however, should be properly small. Otherwise, the system processing delay may occur.
CAUTION:
When using the RRU, you must set the sum of the actual cell handover radius and the fiber transmission delay as the cell handover radius.
Impact on the Network Performance
If the value set for this parameter exceeds the planned value range of a cell, the NodeB fails to handle the users on the radius smaller than the set value. This results in that the actual handover range is smaller than the planned one.

BR,