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Basic Test Procedures
This section gives examples of how to set up and use the
CTS850 SDH/PDH Test Set for several common telecommunication
network applications:
H Network continuity checking
H Transmission signal quality testing
H Fault tolerance testing
H Performance monitoring
H Jitter and wander testing
H Video timing quality testing
Setting Up the CTS850
This section presents setup instructions for the CTS850 in tables.
Perform the steps reading from left to right in the table (see example
below). The word none in a cell indicates that no action is required.
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
Begin here with Step 2 Step 3 Step 4
Step 1
Step 5 Step 6
Step 7 Step 8, CTS850
Setup is complete
Menu buttons are located on the instrument front panel. Select menu
pages with the buttons below the display. Use the knob to highlight a
parameter; then use the buttons at the right to select a choice. Many
setups require several iterations of highlighting parameters and
selecting choices. Some setups may require more than one menu
button or menu page selection as well.
CTS850 SDH/PDH Test Set User Manual 3 1
Basic Test Procedures
The first step in each application setup initializes the CTS850 to a
known state.
Network Continuity Checking
With the AUTOSCAN feature of the CTS850, it is easy to make a
quick continuity check. The continuity check verifies that a SDH
network element (NE), or portion of the network, is correctly set up
and provisioned and that the signal passes through intact. In this
example, the CTS850 transmits an STM-1E signal into an NE. Then
the CTS850 receives the output from the NE and verifies that the
AU-4, including its payload patterns, is intact.
1. Connect the CTS850 to the NE as shown in Figure 3 1.
CTS 850 SDH/PDH Test Set
All Signals are
STM-1E
One or More SDH NEs
Figure 3 1:Setup to Check Network Continuity
3 2 CTS850 SDH/PDH Test Set User Manual
Basic Test Procedures
2. Set up the CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TEST SETUPS RECALL DEFAULT Recall Setup
INSTRUMENT FACTORY
SETUPS SETTINGS
TRANSMIT TRANSMIT Transmit Rate STM-1E
SETTINGS
3. Press the AUTOSCAN button. The receiver locks onto the output
from the NE, displays the signal structure, and shows information
about the content of AU #1.
4. To analyze the payload pattern, select Show Payload. The
CTS850 detects a PRBS of length 223 1.
5. Check the J1 Path Trace for any message.
6. Check the front-panel status lights to verify that there are no
errors, alarms, or failures.
7. Select EXIT to leave the AUTOSCAN dialog box.
Transmission Signal Quality Testing
Measuring Bit Error Rate
The bit error rate (BER) test is one of the best ways to measure the
quality of an SDH transmission link. You can use the CTS850 to
make a BER test on a two-way link that is connected in a loop-back
configuration. If this is a test you perform often, save it as a pass/fail
test for easy recall.
1. Connect the CTS850 to a network as shown in Figure 3 2.
CTS850 SDH/PDH Test Set User Manual 3 3
Basic Test Procedures
CTS 850 SDH/PDH Test Set
All Signals are
STM-1E
One or More SDH NEs NE
Figure 3 2:Setup to Check a Transmission Link
3 4 CTS850 SDH/PDH Test Set User Manual
Basic Test Procedures
2. Set up the CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TEST SETUPS RECALL DEFAULT Recall Setup
INSTRUMENT FACTORY
SETUPS SETTINGS
TRANSMIT TRANSMIT Transmit Rate STM-1E
SETTINGS
Payload Bulk Fill
(Equipped)
Tx/Rx Setup Coupled
TEST SETUPS TEST CONTROL Test Duration 15 Minutes
RESULTS SDH RESULTS none SDh Anomalies
3. Press the START/STOP button.
4. While the test is running, the CTS850 counts errors and errored
seconds and then calculates the error ratio for each error type or
errored seconds.
5. After 15 minutes have elapsed, the test stops automatically and
the measured results are held on the SDH RESULTS page until
another test is started.
6. When the test is complete, you can store the test results to disk or
print out a hardcopy. To save the test results to disk, you must
enter a name for the disk file as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
RESULTS SAVE RESULTS Name EDIT NAME
7. Enter an eight-character name for the file.
CTS850 SDH/PDH Test Set User Manual 3 5
Basic Test Procedures
8. If you wish, you can also enter a description of the test results by
highlighting Description and selecting EDIT TEXT.
9. Save the test results to disk as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
Save to Disk Save Current
Testing Mapping and Demapping (All PDH rates)
The following map/demap procedure applies to all PDH rates in the
CTS 850 test set: 2 Mb/s, 8 Mb/s, 34 Mb/s 45 Mb/s and 140 Mb/s.
The example is written in terms of a 2 Mb/s signal, but the basic test
procedure would be the same in all other PDH rates.
To test that a 2 Mb/s signal is correctly mapped into an SDH signal,
you would use a Bit Error Rate test. However, testing mapping/
demapping requires a different test setup than that described on
page 3 3.
In this example, the Transmitter is generating a 2 Mb/s test signal
which is mapped into a STM 1 signal by the Add/Drop Mux. The
Receiver monitors the STM 1 signal received from the Add/Drop
Mux, demaps the 2 Mb/s test signal and verifies the test pattern
received.
1. Connect the CTS850 to an Add/Drop Multiplexer (ADM) as
shown in Figure 3 3.
3 6 CTS850 SDH/PDH Test Set User Manual
Basic Test Procedures
CTS 850 SDH/PDH Test Set
2 Mb/s or any
PDH rate
STM 1
2 Mb/s or
any PDH rate
Add/Drop Mux
Figure 3 3:Setup to Test Mapping and Demapping
CTS850 SDH/PDH Test Set User Manual 3 7
Basic Test Procedures
2. Set up the CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TEST SETUPS RECALL DEFAULT Recall Setup
INSTRUMENT FACTORY
SETUPS SETTINGS
TRANSMIT TRANSMIT Transmit Rate 2 Mb/s or any
SETTINGS PDH rate
RECEIVE RECEIVE Receive Rate STM-1
SETTINGS
Structure TU 12Async or
applicable TU x
TU Under Test Set to match how
the NE is
provisioned
Payload 2 Mb/s Unframed
or any PDH rate
TEST SETUPS TEST CONTROL Test Duration 15 Minutes
RESULTS SDH RESULTS none Defects
3. Press the START/STOP button.
While the test is running, the CTS850 counts errors and errored
seconds and then calculates the error ratio for each error type.
After 15 minutes have elapsed, the test stops automatically and the
measured results are held on the SDH RESULTS page until another
test is started.
3 8 CTS850 SDH/PDH Test Set User Manual
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4. When the test is complete, you can store the test results to disk or
print out a hardcopy. To save the test results to disk, you must
enter a name for the disk file as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
RESULTS SAVE RESULTS Name EDIT NAME
5. Enter an eight-character name for the file.
6. If you wish, you can also enter a description of the test results by
highlighting Description and selecting EDIT TEXT.
7. Save the test results to disk as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
Save to Disk Save Current
Fault Tolerance Checking
Fault tolerance testing (sometimes called stimulus/response testing or
stress testing) is used to ensure that a network responds correctly to
various fault conditions. Though there are many additional fault
conditions you can test with the CTS850, this section covers three
common examples:
H Response to errors and alarms
H Response to pointer movements
H Response to line frequency offset
Response to Errors and Alarms
This example uses two CTS850 testers to simultaneously check the
upstream and downstream responses to an error or alarm condition.
You can use a single CTS850 to do the same thing by alternately
CTS850 SDH/PDH Test Set User Manual 3 9
Basic Test Procedures
connecting the upstream and downstream signals to the RECEIVE
input.
Table 3 1 shows the responses expected from Line Terminating
Equipment (LTE), such as an STM-4/STM-1 multiplex section
terminating element, when presented with three possible error and
alarm conditions.
Table 3 1:LTE Responses to Errors and Alarms
Transmitted Error or Expected Upstream Expected Down-
Alarm Response stream Response
RS B1 Error MS REI none
MS AIS MS RDI AU AIS
HP RDI none HP RDI
LOS MS RDI AU AIS
1. Connect two CTS850s to an LTE as shown in Figure 3 4.
CTS 850 SDH/PDH Test Set CTS 850 SDH/PDH Test Set
All Signals are
STM-1E
Downstream
LTE
Upstream
Figure 3 4:Setup to Check Error and Alarm Response
3 10 CTS850 SDH/PDH Test Set User Manual
Basic Test Procedures
2. To check the LTE response to an RS B1 error, set up the upstream
CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TEST SETUPS RECALL DEFAULT Recall Setup
INSTRUMENT FACTORY
SETUPS SETTINGS
TRANSMIT TRANSMIT Transmit Rate STM-1E
SETTINGS
Tx/Rx Setup Coupled
TRANSMIT Defects & Error Type RS B1
Anomalies
Error Rate set to 1.0E 5
RESULTS SDH RESULTS none SDH Anomalies
CTS850 SDH/PDH Test Set User Manual 3 11
Basic Test Procedures
3. Set up the downstream CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TEST SETUPS RECALL DEFAULT Recall Setup
INSTRUMENT FACTORY
SETUPS SETTINGS
RECEIVE RECEIVE Receive Rate STM-1E
SETTINGS
RESULTS SDH RESULTS none Defects
4. Press the START/STOP buttons on both the upstream and
downstream CTS 850 units so that the START/STOP lights are
on.
5. Verify that RS B1 BIP errors are counted in the SDH RESULTS
display of the upstream CTS850.
6. Verify there are no errors counted in the SDH RESULTS display
of the downstream CTS850.
7. Press the START/STOP buttons on both the upstream and
downstream CTS850s so that the START/STOP lights are off.
8. To check the LTE response to an MS AIS alarm, change the
upstream CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TRANSMIT Defects & Error Rate set to None
Anomalies
Transmit Alarm MS AIS
set to
RESULTS SDH RESULTS none SDH Defects
3 12 CTS850 SDH/PDH Test Set User Manual
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9. Change the downstream CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
Results Main Results SDH Defects none
10. Press the START/STOP buttons on both the upstream and
downstream CTS850 units so that the START/STOP lights are on.
11. Verify that MS AIS alarm seconds are counted in the SDH
RESULTS display of the upstream CTS850.
12. With the downstream CTS850, verify that the displayed K1 or K2
bytes are not all zeros.
13. Press the START/STOP buttons on both the upstream and
downstream CTS850s so that the START/STOP lights are off.
14. To check the LTE response to a HP RDI alarm, change the
upstream CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TRANSMIT Defects & Error Rate set to None
Anomalies
Transmit Alarm HP RDI
set to
RESULTS SDH RESULTS none Defects
CTS850 SDH/PDH Test Set User Manual 3 13
Basic Test Procedures
15. Change the downstream CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
RESULTS SDH RESULTS none Anomalies
16. Press the START/STOP buttons on both the upstream and
downstream CTS850 units so that the START/STOP lights are on.
17. Verify that the HP RDI light is on, on the downstream CTS850.
Response to Pointer Movements
Pointers allow the SDH network to multiplex signals from indepen-
dent sources, even if the signal clock rates differ slightly from each
other. Within the allowed range, pointer movements should have no
adverse affect on the performance of the network.
This example transmits a signal with frequent pointer movements to
an NE and checks that the downstream signal is error free.
1. Connect the CTS850 to an NE as shown in Figure 3 5.
3 14 CTS850 SDH/PDH Test Set User Manual
Basic Test Procedures
CTS 850 SDH/PDH Test Set
NE
All Signals are
STM-1E
Figure 3 5:Setup to Check Pointer Movements
CTS850 SDH/PDH Test Set User Manual 3 15
Basic Test Procedures
2. Set up the CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TEST SETUPS RECALL DEFAULT Recall Setup
INSTRUMENT FACTORY
SETUPS SETTINGS
TRANSMIT TRANSMIT Transmit Rate STM-1E
SETTINGS
Tx/Rx Setup Coupled
TRANSMIT POINTERS & Pointer Control Continuous
TIMING
RESULTS SDH RESULTS none Defects
3. Press the START/STOP button on the CTS850 so that the
START/STOP light is on.
4. Verify that there are no errors in the SDH RESULTS display.
When the front-panel ERROR light is not on, it also indicates
there are no errors in the received signal.
5. To check for received pointer movements, change the CTS850
setup as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
RESULTS SDH RESULTS none Pointers
6. Verify that the CTS850 is counting positive pointer justifications.
Depending on the clock rate of the NE, some negative pointer
justifications are also possible.
3 16 CTS850 SDH/PDH Test Set User Manual
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Response to Line Frequency Offset
Pointers also accommodate differences in line frequency from one
NE to another. In this example, the CTS850 transmits a signal at an
offset line frequency to an NE and measures the response.
1. Connect the CTS850 to an NE as shown in Figure 3 6.
CTS 850 SDH/PDH Test Set
NE
All Signals are
STM-1E
Figure 3 6:Setup to Check Line Frequency Offset Response
CTS850 SDH/PDH Test Set User Manual 3 17
Basic Test Procedures
2. Set up the CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TEST SETUPS RECALL DEFAULT Recall Setup
INSTRUMENT FACTORY
SETUPS SETTINGS
TRANSMIT TRANSMIT Transmit Rate STM-1E
SETTINGS
Tx/Rx Setup Coupled
TRANSMIT POINTERS & Pointer/Timing Frequency Offset
TIMING Mode
Offset Mode Line
Frequency Offset Stress +4.6 ppm
RESULTS SDH RESULTS none Network Defects
Section Defects
Path Defects
3. Press the START/STOP button on the CTS850 so that the
START/STOP light is on.
4. Verify that there are no errors in the SDH RESULTS displays.
When the front-panel ERROR light is not on, it also indicates
there are no errors in the received signal.
5. To check that the NE is generating pointer movements, change
the CTS850 setup as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
RESULTS SDH RESULTS none Pointers
6. Verify that negative pointer justifications are being counted.
3 18 CTS850 SDH/PDH Test Set User Manual
Basic Test Procedures
Performance Monitoring
When a new line is installed you may want to monitor performance
for a day or so to be sure it is operating correctly. Or, if problems are
suspected on a line, you may want to run a long test to determine the
cause of the problem. In either case, the CTS850 makes it easy to
monitor an electrical or optical line without the need for splitters.
During a test, the CTS850 simultaneously takes all performance
measurements, analyzes the results according to the G.821 standard,
and displays the measurements and analysis in your choice of three
formats:
H In a brief summary
H In detail by type (defect, anomaly, alarm, failure)
H In detail by layer (regenerator section, multiplexer section, path)
In this example, the CTS850 is placed directly in line with a live
optical signal to monitor performance in an unintrusive mode
(Through Mode).
1. Connect the CTS850 in line with an optical signal as shown in
Figure 3 7.
CTS850 SDH/PDH Test Set User Manual 3 19
Basic Test Procedures
CTS 850 SDH/PDH Test Set
NE NE
All Signals are STM-1
Figure 3 7:Setup to Monitor Performance
2. Set up the CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TEST SETUPS RECALL DEFAULT Recall Setup
INSTRUMENT FACTORY
SETUPS SETTINGS
RECEIVE RECEIVE Receive Rate STM-1
SETTINGS
TRANSMIT TRANSMIT Tx/Rx Setup Through Mode
SETTINGS
RESULTS ERROR none SDH G.821
ANALYSIS Analysis
3. Press the START/STOP button on the CTS850 so that the
START/STOP light is on.
4. As the test is running, the analysis of Regenerator Section errors
continually updates. You can also look at the analysis of
3 20 CTS850 SDH/PDH Test Set User Manual
Basic Test Procedures
Multiplexer Section, Path, or Payload errors by pressing the
buttons corresponding to those choices.
5. To see network performance data since the start of the test
presented in graphical form, change the CTS850 setup as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
RESULTS HISTORY none none
GRAPHS
6. The CTS850 history coverage is based on storage interval which
is determined by TEST SETUP. You can choose history graphs of
the measured performance indicators in the following categories:
H Error count (any error you choose)
H Errored seconds (any error you choose)
H Pointer justifications
H Pointer value
H All failures
H All alarms
CTS850 SDH/PDH Test Set User Manual 3 21
Basic Test Procedures
7. For example, to change the bottom graph to display the history of
Path B3 Errored Seconds, change the CTS850 setup as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
RESULTS HISTORY none Change Bottom
GRAPHS
turn the knob to Path B3 Errored
select the desired Secs
graph
Select Graph
8. Turning the knob moves the cursor from one bar to the next. The
specific measurement values at the cursor location are shown in
the display.
9. Once the graph fills the width of the display, you can pan through
the entire test using the knob.
10. You can compress or expand the time scale with the Zoom Out or
Zoom In action buttons. Press the button next to Zoom Out to
change the time scale to 5 minutes per bar.
3 22 CTS850 SDH/PDH Test Set User Manual
Basic Test Procedures
Jitter/Wander Testing
With the CTS850 jitter generation and analysis capability, it is easy
to run the following automated ITU jitter conformance tests:
H Jitter Tolerance
H Jitter Transfer
H Output Jitter (Jitter Generation)
H Pointer Jitter
This section shows examples of the jitter tolerance, jitter transfer and
video timing quality tests.
Testing Jitter Tolerance
The CTS850 generates a signal that contains jitter at various
frequencies and feeds it to the network element. Simultaneously, the
CTS850 receives the output from the network element and analyzes
its performance.
You can specify several parameters for the test:
H Mask type for jitter analysis
H Start frequency
H End frequency
H Number of frequency samples
H Tolerance criteria
The results are displayed in numerical and graphical form.
The CTS850 provides two methods to measure the tolerance of a
network element to jitter applied at its input:
H Onset-of-errors method
H 1 dB power penalty (BER) method
These methods are fully specified and described in the ITU-T
Recommendation O.171 test set standard.
CTS850 SDH/PDH Test Set User Manual 3 23
Basic Test Procedures
Onset-of-Errors Method. The onset-of-errors method measures the
error output of a network element when jitter is applied to its input.
If there are two or more Errored Seconds in a 30-second time
interval, then the CTS850 plots the jitter frequency and amplitude on
a graph and compares it to a mask you can choose.
1. Connect the CTS850 to the network element as shown in
Figure 3 8.
CTS 850 SDH/PDH Test Set
These two NE
signals are
STM 1E
Figure 3 8:Setup to Check Onset-of-Errors Jitter Tolerance
2. Set the transmit and receive signals to STM-1E.
3 24 CTS850 SDH/PDH Test Set User Manual
Basic Test Procedures
3. Set up the CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TRANSMIT JITTER & Output Jitter Line
WANDER
TEST SETUPS JITTER TESTS Test Type Jitter Tolerance
Test Control Edit Setup
Mask Type as appropriate
Start Frequency as appropriate
End Frequency as appropriate
Number Freq as appropriate
Samples
Tolerance Criteria Onset of Errors
4. Press the START/STOP button on the CTS850 so that the
START/STOP light is on.
As the test is running, the jitter tolerance graph is displayed on the
screen. The results of each frequency point will also be displayed.
The test stops automatically after it has completed. The CTS 850
will also display whether the test passed or failed.
CTS850 SDH/PDH Test Set User Manual 3 25
Basic Test Procedures
1 dB Power Penalty Method. The 1 dB power penalty method uses the
BER to measure the amount of jitter that is equivalent to a 1 dB loss
of signal power at the optical input of a network element.
1. Connect the CTS850 to the network element as shown in
Figure 3 9.
CTS 850 SDH/PDH Test Set
All Signals are STM-1
Variable
optical NE
attenuator
Figure 3 9:Setup to Check 1 dB Power Penalty Jitter Tolerance
3 26 CTS850 SDH/PDH Test Set User Manual
Basic Test Procedures
2. Set up the CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TRANSMIT JITTER & Jitter Output Line
WANDER
TEST SETUPS JITTER TESTS Test Type Jitter Tolerance
Test Control Edit Setup
Mask Type as appropriate
Start Frequency as appropriate
End Frequency as appropriate
Number Freq as appropriate
Samples
Tolerance Criteria BER
Record Error Measure BER
Threshold
3. Observe the Current BER and Recommended BER values in the
display. Increase the optical attenuation until the Current BER
reaches or exceeds the Recommended BER.
4. When the Current BER exceeds the Recommended BER:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TEST SETUPS JITTER TESTS Record Error Record BER
Threshold
5. Reduce the optical attenuation by 1 dB.
6. Press the START/STOP button on the CTS850 so that the
START/STOP light is on.
CTS850 SDH/PDH Test Set User Manual 3 27
Basic Test Procedures
The CTS850 applies progressively increasing jitter to the input until
the Current BER reaches the threshold you set. At that time, the test
stops automatically and the results are displayed.
Testing Clock-to-Line Jitter Transfer
This test measures the transfer function for jitter in the output of a
network element relative to jitter in its clock. The CTS850 generates
a 2 MHz G.703 clock signal containing jitter that is connected to the
network element. The CTS850 also generates a jitter-free test pattern
connected to the input of the network element. Then, the CTS850
receives the output from the network element and analyzes its
performance.
You can specify several parameters for the test:
H Mask type for jitter analysis
H Start frequency
H End frequency
H Number of frequency samples
The results are displayed in numerical and graphical form.
1. Connect the CTS850 to the network element as shown in
Figure 3 10.
3 28 CTS850 SDH/PDH Test Set User Manual
Basic Test Procedures
2 MHz G.703 clock
from J/CLK OUT
CTS 850 SDH/PDH Test Set
Clock input
NE
All Signals are
STM-1E
Figure 3 10:Setup to Check Clock-to-Line Jitter Transfer
CTS850 SDH/PDH Test Set User Manual 3 29
Basic Test Procedures
2. Set up the CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TRANSMIT JITTER & Jitter Output MHz G.703
WANDER
RECEIVE JITTER & Jitter Input Line
WANDER Source
TEST SETUPS JITTER TESTS Test Type Jitter Transfer
Test Control Edit Setup
Mask Type as appropriate
Start Frequency as appropriate
End Frequency as appropriate
Number Freq as appropriate
Samples
3. Press the START/STOP button on the CTS850 so that the
START/STOP light is on.
As the test is running, the jitter transfer graph is displayed on the
screen. The test stops automatically after it has completed.
3 30 CTS850 SDH/PDH Test Set User Manual
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Video Timing Quality Testing
Compressed digital video signals transmitted over a network can be
impaired by low-frequency jitter or frequency drift that may be
acceptable in other applications. One source of this jitter is pointer
movement used to synchronize SDH payloads across a network. You
can use the CTS850 to analyze jitter in a PDH signal due to pointer
movement in the SDH signal. Two new measurements, Frequency
Drift Rate and Pointer Hit Seconds, help show this effect.
The CTS850 generates a SDH signal containing a sequence of
pointer movements. The CTS850 analyzes the timing of the dropped
34 Mb/s signal.
1. Connect the CTS850 to the network element as shown in
Figure 3 11.
CTS 850 SDH/PDH Test Set
34 Mb/s
STM-1
34 Mb/s
Add/Drop Mux
Figure 3 11: Setup to Check Video Timing Quality
CTS850 SDH/PDH Test Set User Manual 3 31
Basic Test Procedures
2. Set up the CTS850 as follows:
Press Menu Select Menu Highlight
Button Page Parameter Select Choice
TRANSMIT TRANSMIT Transmit Rate STM-1E
SETTINGS
Structure TU3 Async
TRANSMIT JITTER & Jitter Output Line
WANDER
TRANSMIT POINTERS & Pointer/Timing Pointer
TIMING Mode Sequences
Pointer Type AU Pointer
Sequence Type Periodic 87 3
RECEIVE RECEIVE Receive Rate 34 Mb/s
SETTINGS
RESULTS SDH RESULTS none Jitter
3. Press the POINTER ACTION button to start the pointer
sequence.
4. Press the START/STOP button on the CTS850 so that the
START/STOP light is on.
As the test is running, results are displayed on the screen. The test
stops automatically after it has completed.
3 32 CTS850 SDH/PDH Test Set User Manual