The forward data channel (FDC) is the out-of-band communication line from the headend to the host. The modulation scheme is QPSK, with typical data rate of 1.544Mbps. The frequency range is from 70MHz to 130MHz with step size of 250KHz.
Equipment: Host under test, CableCARD, television, Spectrum analyzer, two-way splitter, and variable attenuator.
NOTE: Test to be performed at 75.25 MHz, 1.544 Mbps, +/- 15 dBmV
Procedure:
Step#
Procedure
Pass/Fail
PICS
Connect the RF network to the HOST DEVICE (with CableCARD inserted).
N/A
From head-end controller set the FDC carrier to the desired frequency. Measure the amplitude level using the spectrum analyzer. Adjust the FDC carrier level to –15dBmV (lowest limit).
Send Inband_tune_req() command to tune HOST DEVICE to mid channel.
N/A
Verify the host can still receive FDC with a RF Input level range of -15 dBmV and +15 dBmV.
HFDCrf.8
3.2.2FDC tuning range and bit rate test
This test verifies tuning range for all three OOB transmission bit rates and verifies reception with channel impairment.
Equipment:
DUT,
TTC Fireberd 6000A communications analyzer,
PRBS generator (Broadcom BCM93133)
HPNX PRO emulator,
CableCARD extender with FDC serial out (clock on pin CBE1, data on pin AD14),
Set the Ghost generator secondary path to Phase, -13 dB @ 0.5 uSec, 0 degrees referenced to RF channel center freq.
N/A
Re-Calibrate QPSK source to -7 dBmV, @ input to DUT and tune OOB tuner.
N/A
From HPNX PRO, open OOB_RX_tune_req menu tab.
N/A
Enter Frequency 125000
N/A
Set Bit Rate same as Synth Frequency of Fireberd.
N/A
Check Spectrum Inv. Depending upon RF Modulator Modulation. (Try one then the other if you are not sure).
N/A
Click “Send” and verify in trace window that tuning is granted.
N/A
Verify that Fireberd received data matches transmit data and Bit error rate is BER<1x10E-10 (after error correction) error rate or better.
(i.e. 1 error in 2 hours at 1.5 Mbps/s)
HFDCrf.12
HFDCrf.24
HFDCrf.27
HFDCrf.7
HFDCrf.5
HFDCrf.27a
HFDCrf.23
FDCP.3
3.2.3FDC Adjacent Channel BER Test
This test verifies OOB transmission bit rates and the performance of FDC reception in the presence of higher power adjacent channels of various modulation types.
Note: Do all padding after the output of the mixer only.
Procedure:
Step#
Procedure
Pass/Fail
PICS
Setup Firebird:
Data: 215-1; Gen Clk: Synth; Timing Mode: Sync; Menu Intf Setup: Lab;
Menu Synth Freq:
Test each Frequency; (1.544Mbps, 2.048Mbps and 3.088Mbps);
Set Signal Gen Freq: (1.544Mbps, 2.048Mbps and 3.088Mbps);
Test the three Bit Rates:
Change Signal Gen Freq for each Test.
Setup the Firebird Analysis Results:
Signal/ Rcv Frequency and Error Bit Errs; Analysis Mode: Continuous.
N/A
Setup QAM/QPSK modulator:
Data source PRBS 215-1,
Change Symbol rates for each test:
0.772Msymbols for 1.544Mbps Test.
1.024Msymbols for 2.048Mbps Test.
1.544Msymbols for 3.088Mbps Test.
Note:
If output is 44 MHz IF only, use RF mixer and RF generator (30 MHz, @10 dBm) to generate 74 MHz QPSK signal.
Measure and pad attenuation of the 44Mhz IF output from QPSK modulator with Spectrum Analyzer to -7 dBmV.
Combine 44Mhz IF with 30Mhz Signal Generator into mixer for 74 MHz signal. Measure and pad attenuation this output signal +/- 15dBmv.
N/A
Verify QAM/QPSK modulator configuration:
Operational control on front panel display: QAM 4, No FEC, PRBS_15, SYM Fixed (0.772, 1.024, or 1.544) CH=N/A, a=0.12, IF=44.0, MPEG:N/A, s=NORM, INTLVR:N/A
N/A
Connect Fireberd serial Rx data to DUT Sycard pin AD14 and Rx Clock to pin CBE1 using TTL buffer to 75 ohm driver adapter.
N/A
Insert the Sycard into the DUT.
N/A
Bring up the HPNX Pro software on the given PC. PC and HPNX Pro need to be on the same isolated network.
N/A
Note the last 4 (mac address) digits of HPNx Pro you are using.
(Information is on the back side of card)
N/A
Under the Device tab, enter the 4 digits in the blank space labeled “Your HPNx Pro ID”.
N/A
Insert the HPNX Pro extender card into DUT. From the HPNx Pro trace window, verify that the status of the HPNX Pro goes ready and the resource manager opens its session.
N/A
Right click on the Trace window to select SPDU and Payload for full vision of all layers.
N/A
Go to Host Control, click play in “session slot”. Host Control menu shows Session nb (opened). Trace window shows Open Session request/response from Host Control.
N/A
From HPNX PRO, open OOB_RX_tune_req menu tab.
Enter Frequency 74000
Set Bit Rate same as Sync Frequency of Fireberd.
Check Spectrum Inv. Depending upon RF Modulator Modulation. (Try one then the other if you are not sure).
Click “Send” and verify in trace window that tuning is granted.
N/A
Verify the Fireberd tester receiver Locks “Sync” (Green) and “MK, SP” LEDs stay yellow.
(FYI) Procedure for Fireberd Setup Ref:
Under Analysis Results menu arrow up/down to set left side category to Signal
Arrow right/left to set RCV Frequency on display.
(RCV Frequency should be Bit Rate sent from HPNX PRO)
Setup Fireberd for BER in Analysis Results right side menu by arrow up/down to ERROR; (use arrow right/left to display either errors: BER or Ave. BER).
N/A
Setup a 64QAM output to GI C6U tuned to EIA 5. Combine 64QAM with mixed QPSK signal into a RF combiner signals to DUT input.
Verify DUT FDC locked @ 74MHz and that Firebird received data Sync Locks to Bit Rates:
Sync Lock Threshold table:
Sync RCV Frequency 1.544Mbps (are <=1 error in two hours or better).
Sync RCV Frequency 2.048Mbps (are <=1 error in two hours or better).
Sync RCV Frequency 3.088Mbps (are <=1 error in two hours or better).
Bit Rate
Pass/Fail
1.544 Mbps
2048 Mbps
3088 Mbps
FDCP.2
HFDCrf.8
HFDCrf.19
HFDCrf.25
HFDCrf.29
HFDCrf.32
HFDCrf.23
After above section of testing is completed change setup to test adjacent channel NTSC analog channel 5 source. Combine NTSC into RF combiner with QPSK for this adjacent channel test.
Verify DUT FDC locked @ 74MHz and that Firebird received data Sync Locks to Bit Rate.
Sync Lock Threshold table:
Sync RCV Frequency 1.544Mbps (are <=1 error in two hours or better).
Sync RCV Frequency 2.048Mbps (are <=1 error in two hours or better).
Sync RCV Frequency 3.088Mbps (are <=1 error in two hours or better).
Bit Rate
Pass/Fail
1.544 Mbps
2048 Mbps
3088 Mbps
FDCP.2
HFRDCrf.27a
HFDCrf.29
HFDCrf.33
HFDCrf.23
Add a QPSK carrirer at 74Mhz @ -7 dBmV, and 256QAM at the adjacent channel (channel 5, Center Freq 79Mhz @ +15dBmV).
N/A
Verify DUT FDC locked @ 74MHz and that Firebird received data Sync Locks to Bit Rate.
Sync Lock Threshold table:
Sync RCV Frequency 1.544Mbps (are <=1 error in two hours or better).
Sync RCV Frequency 2.048Mbps (are <=1 error in two hours or better).
Sync RCV Frequency 3.088Mbps (are <=1 error in two hours or better).
Bit Rate
Pass/Fail
1.544 Mbps
2048 Mbps
3088 Mbps
HRFAcc.6
Add a QPSK carrirer at 74Mhz @ -7 dBmV, and 64QAM at the adjacent channel (channel 5, Center Freq 79Mhz @ +15dBmV).
N/A
Verify DUT FDC locked @ 74MHz and that Firebird received data Sync Locks to Bit Rate.
Sync Lock Threshold table:
Sync RCV Frequency 1.544Mbps (are <=1 error in two hours or better).
Sync RCV Frequency 2.048Mbps (are <=1 error in two hours or better).
Sync RCV Frequency 3.088Mbps (are <=1 error in two hours or better).
Bit Rate
Pass/Fail
1.544 Mbps
2048 Mbps
3088 Mbps
HRFAcc.6
Add a QPSK carrirer at 74Mhz @ -7 dBmV, and NTSC at the adjacent channel (channel 5, Center Freq 79Mhz @ +15dBmV).
N/A
Verify DUT FDC locked @ 74MHz and that Firebird received data Sync Locks to Bit Rate.
Sync Lock Threshold table:
Sync RCV Frequency 1.544Mbps (are <=1 error in two hours or better).
Sync RCV Frequency 2.048Mbps (are <=1 error in two hours or better).
Sync RCV Frequency 3.088Mbps (are <=1 error in two hours or better).
