Max and Min DPCH power setting18 April 2006
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Company Confidential
PtxTotal Measurements
PtxTotal means the total transmitted power in a cell
43dB
42dB
CLASS
AREA
PtxTotal = power of all CCHs on (no UEs in cell_DCH)
CLASS 1
CLASS 2
Minimum DL TX Power per Radio Link
Admission Control determines the initial, the minimum, and the maximum downlink transmission powers for new user.
BTS maximum
output power
Simplified formula
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Maximum DL TX Power per Radio Link
When radio link is established both maximum DL transmission power and minimum DL transmission power has to be determined
The maximum power for a reference service is set relative to transmission power of CPICH
Scaling Factor
The maximum power of a connection is set by scaling factor, based on bit rate and Eb/No compared to the reference service
Maximum for DL DPCH transmission power
PtxCPICH, (PtxPrimaryCPICH) is the transmission power of the primary CPICH, CPICHToRefRabOffset (CPICHtoRefRABoffset) is the offset of the primary CPICH transmission power and the DL transmission power of the reference call.
The pilot sets the dominance area for the cell.
Two code channel transmission power threshold parameters are:
configuration parameter PtxDPCHMax defines the absolute maximum for DL DPCH transmission power (maximum transmit output power of code channel), default = -3dB (below the max BTS output power)
configuration parameter PtxDPCHMin defines the absolute minimum for DL DPCH transmission power (minimum transmit output power of code channel), default -28dB (below the max BTS output power)
These parameters give the upper and lower limits of the DL transmission power a code channel can have in a BTS cell
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PtxDLabsMax from 50 to 40,
PtxDPCHMin from -28 to-31
Recommendations:
All the cells that have enough capacity (HW and transmission) the initial bitrate should be 64 and max 384
The cells having less capacity should have max bitrate = 128 kbps
Triggering for DYLO
When radio link is established or modified, both maximum DL transmission power Ptxmax and minimum DL transmission power Ptx,min has to be determined for it
The average power of transmitted DPDCH symbols over one timeslot must not exceed maximum DL transmission power, or it can not be below minimum DL transmission power.
Dylo starts in case PtxMax or PTxDLAbsMax has been achieved by certain offset parameter:
Ptx,average + DLOptimisationPwrOffset > Ptx,threshold
t
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DL pwr (dBm)
This is where DLO triggers. (If PtxDLabsMax is set high)
Default hidden value is 2dB
Ptx, threshold
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DL pwr (dBm)
This is where DLO now triggers.
Ptx, threshold