Expected Power

Last updated: November 23, 2010

The expected power is the mobile station output power that should be present at the test set's RF IN/OUT port. It is used to range the test set's receiver. The valid range for expected power is from -69 dBm to the maximum output power allowed for the mobile station which is the Max EIRP reported on the Call Setup screen in the Mobile Reported Information window.

In CW operating mode, you must specify the CW expected power that the test set should range its receiver to (see Receiver Control ).

In active cell mode (IS-2000 or IS-95 system) or IS-2000 Test mode, by default, receiver power control is set to auto (see Receiver Control ). In this mode, expected power is used to set the measurement and demodulation receiver power ranges. Expected power is calculated by the test set, and is displayed on many of the transmitter power measurement screens such as the digital average power, the channel power, and the access probe power.

Expected power is determined based on the open loop power equation of the mobile station and the parameter values such as Cell Power, Access Parameters, Enhanced Access Parameters, Data Rate, etc.

The calculation of expected power varies according to the state of the call connection, which reverse channels being transmitted by the mobile station, etc. See Expected Power Calculations for details.

Expected Power Calculations
		IS-95 System	IS-2000 System Radio Config = (Fwd1, Rvs1), (Fwd2, Rvs2)¹		IS-2000 System Radio Config = (Fwd3, Rvs3), (Fwd4, Rvs3), (Fwd5, Rvs4), (Fwd11, Rvs8)¹
Access Channel Type ²		R-ACH	R-ACH	R-EACH	R-ACH	R-EACH
Active Cell Connection Status	Idle	Equation A (R-ACH)		Equation B (R-EACH with R-Pilot)	Equation A (R-ACH)	Equation B (R-EACH with R-Pilot)
Active Cell Connection Status	Connected	Equation A (Reverse traffic channel ³ )			Equation C (Reverse traffic channel ⁴ with R-Pilot)
IS-2000 Test Mode		Not Applicable	Equation A (Reverse traffic channel ³ )		Equation C (Reverse traffic channel ⁴ with R-Pilot)
See Radio Configuration for details. Access Channel Type indicates if the test set is configured for R-ACH or R-EACH when protocol revision is greater than six (see Setting Control Channel Parameters for details). Reverse traffic channel represents R-FCH in Radio Config = (Fwd1, Rvs1), (Fwd2, Rvs2). Reverse traffic channel represents R-FCH and/or R-SCH in Radio Config = (Fwd3, Rvs3), (Fwd4, Rvs3), (Fwd5, Rvs4), (Fwd11, Rvs8). The R-SCH is only added if the test set is configured to recieve R-SCH, for example, IS-2000 Service Option is SO32 (+SCH) or SO33 (with R-SCH channel being assigned).

NOTE

Any calculation in the following sections that indicates X (dBm) = Y (dBm) + Z (dBm) implicitly means: converting Y and Z to Watts firstly, then adding Y and Z in Watts, and finally converting to dBm value for X.

Base Equation

The different equations used to determine the mobile station output power and therefore the expected power share a common base formula and some common parameters. The base equation used by these different calculations is:

Base Power (dBm) = - mean input power (dBm) + offset power + interference correction + access correction , where:

mean input power = Total RF Power (for IS-95 or IS-2000 system) (see Configuring Cell Power and AWGN Power Levels ).
offset power varies depending upon the reverse channels available for different setups (see Offset Power in Different Configurations as specified by the standard)
interference correction = min(max(IC_THRESH - E_c /I_o , 0), IC_MAX)
The interference correction is the adjustment made to correct for interference. The actual values used for IC_THRESH and IC_MAX vary between the different equations (see Equation A , Equation B , Equation C ). The E_c /I_o (dB) is the ratio of the combined pilot energy per chip, E_c , to the total received power spectral density (noise and signals), I_o . The test set determines the E_c /I_o by:
- E_c /I_o = Absolute F-Pilot level (dBm) - Total RF Power (dBm), where Absolute F-Pilot level (dBm) = F-Pilot level (dB) + Cell Power (dBm) (see Setting Code Channel Levels and Walsh Codes and Configuring Cell Power and AWGN Power Levels ). Note that when in soft/softer handoff, the Absolute F-Pilot level (dBm) will be the maximum of Absolute Cell1 F-Pilot Level and Absolute Cell2 F-Pilot Level
access correction varies depending on which access channel (R-ACH or R-EACH) is currently configured. The general equation is:
access corrections = nominal power + initial power + (PWR_LVL * power step size)
The (PWR_LVL * power step size) component is always 0 since the test set assumes the 1st access probe (corresponding to PWR_LVL equal to 0) of the access or enhanced access probe sequence for calculation. Therefore,
- When R-ACH is currently configured,
  access corrections = Nominal Power + Initial Power - 16 * Nominal Power Extended
  (Nominal Power, Initial Power and Nominal Power Extended are settable on the test set, see Setting Access Parameters ).
- When R-EACH is currently configured,
  access corrections = EACH Nominal Power + EACH Initial Power
  (EACH Nominal Power and EACH Initial Power are settable on the test set, see IS-2000 Enhanced Access Parameters )

Offset Power in Different Configurations
Band Class	Reverse Channels	Offset Power
US Cellular, Japan CDMA, NMT-450, Cellular (Upper) 700, China Cellular, Secondary 800, PAMR 400, PAMR 800, Public Safety 700, Lower 700 TACS	Access Channel Reverse Traffic Channel (RC1, RC2) ¹	-73
	Enhanced Access Channel Reverse Common Control Channel Reverse Traffic Channel (RC3, RC4, RC8) ¹	-81.5
US PCS, Korean PCS, IMT-2000, US PCS 1900, AWS, DCS 1800, 2.5GHz IMT-2000 Ext, US 2.5GHz, US 2.5GHz F-Link Only	Access Channel Reverse Traffic Channel (RC1, RC2) ¹	-76
	Enhanced Access Channel Reverse Common Control Channel Reverse Traffic Channel (RC3, RC4, RC8) ¹	-84.5
The RC1 through RC4 refer to the radio configuration for reverse traffic channels. See Radio Configuration for details.

Equation A

See Expected Power Calculations for when this equation is used.

Expected Power (dBm) = Base Power (dBm) + RLGAIN_ADJ , with the following requirements when calculating Base Power (see Base Equation ):

interference correction: IC_THRESH = -7 and IC_MAX = 7 (these values are fixed by the standard)
access corrections = access corrections for R-ACH or R-EACH depending on whichever is currently configured (see Control Channel Configuration ).
RLGAIN_ADJ = 0 (fixed by the test set) (RLGAIN_ADJ only applies to reverse traffic channel)

Equation B

See Expected Power Calculations for when this equation is used.

The R-EACH in basic access mode (the only mode currently supported by the test set) consists of an R-EACH preamble followed by enhanced access data (see Enhanced Access Channel Structure ). The test set does not range expected power for the enhanced access preamble. The test set ranges the expected power for the R-EACH data portion (R-EACH Data and R-Pilot) and is calculated as:

Expected Power (dBm) = R-Pilot power (dBm) + R-EACH power (dBm) , where,

R-Pilot power (dBm) = Base Power, with the following requirements when calculating Base Power (see Base Equation ):

interference correction: IC_THRESH = - Interference Correction Threshold and IC_MAX = Interference Correction Maximum (Interference Correction Threshold and Interference Correction Maximum are settable on the test set, see IS-2000 Enhanced Access Parameters )
access corrections = access corrections for R-EACH

R-EACH power (dBm) = R-Pilot (dBm) + 0.125 * (Nominal Common Attribute Gain + RL Gain Common to Pilot), where,

Nominal Common Attribute Gain = Nominal_Reverse_Common_Channel_Attribute_Gain[Data Rate, Frame Length] (see Nominal Reverse Common Channel Attribute Gain (supported by the test set)
For Data Rate and Frame Length setting, see R-EACH Rate Supported . Note that if multiple rates are supported, the highest supported rate is used for the calculation but the test set will not display the expected power level on the access probe power measurement.
RL Gain Common to Pilot (see IS-2000 Enhanced Access Parameters )

Nominal Reverse Common Channel Attribute Gain (supported by the test set)
Data Rate	Frame Length	Nominal_Reverse_Common_Channel_Attribute_Gain
9.6 kbps	20 ms	30
19.2 kbps	20 ms	50

Equation C

See Expected Power Calculations for when this equation is used.

Which reverse traffic channels contain power varies during Initial Channel Assignment state and Connected state, as shown below

The expected power for each of these states is as follows:

Initial Channel Assignment state consists of a traffic channel preamble (R-Pilot only) followed by a combination of signaling and null frames on the traffic channel (R-FCH). Null frames consist of the R-Pilot and eighth rate traffic channel. Traffic channel signaling consists of the R-Pilot and full rate traffic channel. Expected Power will be ranged for traffic channel signaling (full rate) which is the highest level expected during the Initial Channel Assignment state, when the radio configuration is (Fwd11, Rvs8), the R-ACK1 (if R-ACK is enabled) power is added:

Expected Power (dBm) = R-Pilot (dBm) + R-FCH [full rate] (dBm) + R-ACK1 (dBm)
Connected state consists of the R-Pilot and the final reverse traffic channel at the final data rate (R-FCH,R-SCH if configured, and R-ACK1 if configured when the radio configuration is RC6). Note that the R-SCH power is only added if the test set is configured to receive R-SCH, and the R-ACK1 power is only added if it is enabled when the radio configuration is RC6, for example, IS-2000 Service Option is SO32 (+ SCH).

Expected Power (dBm) = R-Pilot (dBm) + R-FCH [final rate] (dBm) + R-SCH [final rate] (dBm) + R-ACK1 [final rate] (dBm)

The power of each of the reverse channels is calculated as follows:

R-Pilot (dBm) = Base Power + RLGAIN_ADJ, with the following requirements when calculating Base Power (see Base Equation ):

interference correction:
- When R-ACH is currently configured,
  IC_THRESH = -7 and IC_MAX = 7 (these values are fixed by the standard)).
- When R-EACH is currently configured,
  IC_THRESH = - Interference Correction Threshold (settable on the test set, see IS-2000 Enhanced Access Parameters ) and IC_MAX = 7 (fixed by the standard)
access corrections = access corrections for R-ACH or R-EACH depending on whichever is currently configured
RLGAIN_ADJ = 0 (fixed by the test set) (RLGAIN_ADJ only applies to reverse traffic channel)

R-FCH or R-SCH (dBm) = R-Pilot (dBm) + 0.125 * (Nominal_Attribute_Gain[Data Rate, Frame Size, Coding Rate] - Multiple_Channel_Adjustment_Gain[R-FCH or R-SCH] + RL Traffic to Pilot Gain), (Note that this is a simplified equation since other elements in the equation as specified in the standard are fixed to zero by the test set), where:

Nominal_Attribute_Gain [Data Rate, Frame Size, Coding Rate]
See Reverse Link Attribute Adjustment .
Multiple_Channel_Adjustment_Gain[R-FCH or R-SCH]:
- If the test set is not configured to receive R-SCH (reverse channel contains R-FCH and R-Pilot),
  Multiple_Channel_Adjustment_Gain[R-FCH] = 0.
- If the test set is configured to receive R-SCH (reverse channel contains R-FCH, R-SCH and R-Pilot),
  Multiple_Channel_Adjustment_Gain varies according to Pilot_Reference_Level (see Reverse Link Attribute Adjustment ):
  - If R-FCH has the highest Pilot_Reference_Level,
    Multiple_Channel_Adjustment_Gain [R-FCH] = 0
    Multiple_Channel_Adjustment_Gain [R-SCH] = Pilot_Reference_Level [R-FCH]- Pilot_Reference_Level[R-SCH]
  - If R-SCH has the highest Pilot_Reference_Level,
    Multiple_Channel_Adjustment_Gain [R-SCH] = 0
    Multiple_Channel_Adjustment_Gain [R-FCH] = Pilot_Reference_Level [R-SCH]- Pilot_Reference_Level[R-FCH]
RL Traffic to Pilot Gain (settable on the test set, see IS-2000/IS-95 Cell Parameters )

Reverse Link Attribute Adjustment
Data Rate ¹ (kbps)	Frame Size ²	Coding	Nominal_Attribute_Gain	Pilot_Reference_Level
1.5	20 ms	Convolutional	- 47 (no gating) - 10 (R-FCH gating) ³	0
2.7	20 ms	Convolutional	-22	0
4.8	20 ms	Convolutional	-2	0
9.6	20 ms	Convolutional	30	0
1.8	20 ms	Convolutional	-42 (no gating) -2 (R-FCH gating ³ )	3
3.6	20 ms	Convolutional	-13	3
7.2	20 ms	Convolutional	15	3
14.4	20 ms	Convolutional	44	3
19.2	20 ms	Convolutional	50	1
38.4	20 ms	Convolutional	60	11
76.8	20 ms	Convolutional	72	21
153.6	20 ms	Convolutional	84	36
307.2	20 ms	Convolutional	96	54
28.8	20 ms	Convolutional	56	11
57.6	20 ms	Convolutional	72	18
115.2	20 ms	Convolutional	80	32
230.4	20 ms	Convolutional	88	46
19.2	20 ms	Turbo	44	2
38.4	20 ms	Turbo	56	10
76.8	20 ms	Turbo	68	19
153.6	20 ms	Turbo	76	33
307.2	20 ms	Turbo	88	50
28.8	20 ms	Turbo	52	9
57.6	20 ms	Turbo	64	19
115.2	20 ms	Turbo	76	29
230.4	20 ms	Turbo	88	39
3	20 ms	Convolutional	-18	0
5	20ms	Convolutional	0	0
See Reverse Traffic Channel Data Rate Determination for details on how the test set determines the reverse traffic channel data rate. The test set only supports 20 ms frames on reverse traffic channel. R-FCH gating mode is only available in Lab Application . See R-FCH Gating for details.

Reverse Traffic Channel Data Rate Determination
	Service Option ¹	Initial Traffic Channel Assignment (Preamble Period)		Connected State
	Service Option ¹	(Fwd3, Rvs3) (Fwd4,Rvs3) (Fwd11, Rvs8)	(Fwd5, Rvs4)	(Fwd3, Rvs3) (Fwd4, Rvs3)	(Fwd5, Rvs4)	(Fwd11, Rvs8)
R-FCH2	SO1, SO3, SO17, SO68, SO70, SO32768, SO6, or SO14	9.6 kbps (the test set assumes Full rate)	14.4 kbps (the test set assumes Full rate)	2.7 kbps (the test set assumes Quarter rate)	3.6 kbps (the test set assumes Quarter rate)	3.0 kbps (the test set assumes Quarter rate)
	SO2, SO9, or SO55			Depending upon the settings (see Traffic Data Rate ). Full = 9.6 kbps Half = 4.8 kbps Quarter = 2.7 kbps Eighth = 1.5 kbps If Random rate is set, the test set assumes Quarter rate (2.7 kbps)	Depending upon the settings (see Traffic Data Rate ): Full = 14.4 kbps Half = 7.2 kbps Quarter = 3.6 kbps Eighth = 1.8 kbps If Random rate is set, the test set assumes Quarter rate (3.6 kbps)	Depending upon the settings (see Traffic Data Rate ): Full = 9.6 kbps Half = 5.0 kbps Quarter = 3.0 kbps Eighth = 1.8 kbps If Random rate is set, the test set assumes Quarter rate (3.0kbps)
	SO32 (+F-SCH) or SO32 (+SCH)			9.6 kbps (the test set assumes Full rate)	14.4 kbps (the test set assumes Full rate)	9.6 kbps (the test set assumes Full rate)
	SO33, or SO33 (+F-SCH)			9.6 kbps (the test set assumes Full rate)	14.4 kbps (the test set assumes Full rate)	9.6 kbps (the test set assumes Full rate)
R-SCH	SO32 (+SCH) or SO33	Not apply.		Depending upon the R-SCH data rate settings. When SO33 (+SCH) selected, see Configuring the TDSO Supplemental Channel Information and when SO33 selected see The parameters for selecting Service Option 33 (SO33) .
1. For details on service options, see Service Option . 2. In IS-2000 Test Mode, the test set will set expected power and range the receivers to expect a R-FCH at Full rate.

mean R-ACK code channel output power

if the number of cells in the active set = 1,
mean R-ACK code channel output power (dBm) = mean pilot channel output power (dBm) + 0.125 * (Nominal_Reverse_Acknowledgment_Channel_Attribute_Gain + Reverse_Channel_Adjustment_Gain[Channel] - Multiple_Channel_Adjustment_Gain[Channel] + REV_ACKCH_GAIN_ADJ_ACS1s)
if the number of cells in the active set >=2,
mean R-ACK code channel output power (dBm) = mean pilot channel output power (dBm) + 0.125 * (Nominal_Reverse_Acknowledgment_Channel_Attribute_Gain + Reverse_Channel_Adjustment_Gain[Channel] - Multiple_Channel_Adjustment_Gain[Channel] + REV_ACKCH_GAIN_ADJ_ACS2PLUSs)

Where:

Nominal_Reverse_Acknowledgment_Channel_Attribute_Gain:

Nominal Reverse Acknowledgment Channel Attribute Gain Table
R-ACK Channel	Modulation	Nominal_Revers_Acknowledgmen_Channel_Attribute_Gain	Pilot_Referece_Level
R-ACK1	OOK	72	0
R-ACK2/3	BPSK	24	0

Reverse_Channel_Adjustment_Gain[Channel]=0.
Multiple_Channel_Adjustment_Gain[Channel]: See Multiple_Channel_Adjustment_Gain[R-FCH or R-SCH]: .
REV_ACKCH_GAIN_ADJ_ACS1s= R-ACK Channel Adjustment Gain for 1 Cell

REV_ACKCH_GAIN_ADJ_ACS2PLUSs= R-ACK Channel Adjustment Gain for 2 plus Cells

Expected Power

Base Equation

Equation A

Equation B

Equation C

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