LAB 4: SONET (200 points)
Updated 11/17/11
Read the following lab instructions on class web page:
Tutorial on ANT-20E - A SONET Analyzer
ANT-20E SONET Analyzer Manual
NOTE: Your lab must include all the questions. Make sure the questions are all
underlined.
Your lab must include the following:
1Abstract: Summary of what this lab is going to be about.
2List of equipment
3General setup diagram
There are several sections to this lab:
1- Understanding STS frame
2- Examining STS overhead bytes
3- Understanding pointers in STS frame
4- Examining and characterizing an OC48 signal
Part 1:
A- Establish the following electrical connections, assume the DS3 is Framed:
1- Go to ApplicationNew
2- Go to EditSignal Structure
3- Establish PRBS15DS3STS1 SPESTS 1 DUT  STS 1  STS1
SPEDS3 PRBS15
4- Remove the Coax cable between connections 14 and 15 and make sure you
are getting LOS (loss of signal) .
5- Take a snapshot of your network setup
B- Under Instruments add all the available tools, except Pointer Generator and
Analyzer. Note how new buttons are added to ANT-20 window. Click on each one
and examine it.
C- Click on Interface Setting. Answer the following questions:
1- What is the rate of STS-1 signal?
2- What type of line coding are you using?
3- Where is the TX clock coming from?
4- What does the scrambler do? (read the help menu)
D- Open Anomaly/Detect Insertion Tool. Inject errors and observe the error results
on front of the ANT-20E (LEDs on the side) and Anomaly/Detect Analyzer window.
Make sure the measurements are running (press Measurement Start button).
1- Inject B1 error and view it on the Anomaly/Detect Analyzer window. Make
sure the Analyzer only shows B1 errors. Inject single errors. Then, inject 10E6 errors, and then 10E-3 errors. What is happening? Take a snapshot.
2- Repeat the step above and inject TSE. What is TSE? Take a snapshot.
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3- Change TSE error rate to 10E-9. What happens? Explain your observation.
4- Generate Loss of Frame (LOF STS).
5- Repeat part 1 and explain what LOF is.
C- Make sure the system is running error free. Open the Overhead Generator Tool.
Record the values of A1 and A2.
1. Change one of them by clicking on the byte in the window. What happen?
2. What kind of errors are you receiving? Explain what is happening.
3. What type of overhead bytes are A1 and A2?
Part 2:
A- Open Overhead Generator and Analyzer windows. Pay attention to the values of
B1, B2 and B3 bytes. Why are they changing on the Analyzer window?
B- In the Overhead Generator window change the value of J0 byte to 44. What
happens?
C- In the Overhead Generator window change the value of K1 and K2 bytes to 44.
What happens? What are these byte used for?
D- Explain exactly the purpose of J1 byte. What is the value specified in J1 byte that
is being sent? Draw an STS frame and show the J1 byte in the payload.
E- In the Overhead Generator window what is the purpose of the TI button. Click on
this button and type in your name. Go the analyzer window and click on TI button.
What do you see? Using an STS frame diagram (similar to above) show exactly what
s happening.
Part 3:
Make sure you stopped the measurements. For this section you must add Overhead
Generator, Overhead Analyzer, Pointer Generator, and Pointer Analyzer tools. You
can obtain these from ANT-20E window.
A- What are the values of H1 and H2? What is the purpose of these bytes? Assuming
H1, H2 and H3 bytes are all 60 00 00, respectively, draw an STS frame and show
where the SPE is located at. You need to read the manual.
B- Go to Pointer Generator window and change the NEW VALUE to be 0. Click on
STS button in the window. What change do you observe on received H1-H3 bytes?
Explain your answer.
C- Repeat the step above and explain what happened to the received H2. Take a
snapshot.
D- Start the measurements and make sure the network is error free. Open the
Pointer Analyzer window. Go to Pointer Generator window and click on the DEC
button. Then Click on STS to start changing pointers. What is happening? How are
H1 and H2 byte changing? Take a snapshot of the Pointer Analyzer window.
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E- Start the measurements and make sure the network is error free. Open the
Pointer Analyzer window. Go to Pointer Generator window and click on the INC
button. Then Click on STS to start changing pointers. What is happening? How are
H1 and H2 byte changing? Take a snapshot of the Pointer Analyzer window.
We now look at K1 and K2 bytes.
G- In the Overhead Generator window click on click on DCT button. Observe
different options for K1 and K2.
H- What is the value of K1 when Span Switching is performed? Use a diagram and
show a span switching due a link failure. Use the Overhead Analyzer window to
verify that the correct value is received. Take a snapshot.
I- Answer the following questions:
1. What is the purpose of S1 byte in STS frame?
2. What are the options that it can take? What is different between Stratus 1
and 2?
3. What does it mean when we say stratum 1 is traceable?
J- Change S1 byte and make sure the correct value was received. Take a snapshot.
Part IV:
A- Establish the following optical connections, assume the DS3 is Framed:
1- Go to ApplicationNew
2- Go to EditSignal Structure
3- Establish PRBS15DS3OC48 (channel 1) DUT etc.
4- Make sure the optical switch and attenuator are enabled.
5- At this point you should have optical traffic passing through the switch and
attenuator.
6- Change the switch position and you should get LOS. This ensures your
connections and setup are correct.
B- What is the value of A1 and A2 byte? Explain your answer.
C- Open Anomaly/Detect Insertion Tool. Inject errors and observe the results on the
front of ANT-20E (LEDs on the side) and Anomaly/Detect Analyzer window. Make
sure the measurements are running (press Measurement Start button).
1- Inject B1 error and view it on the Anomaly/Detect Analyzer window. Make
sure the Analyzer only shows B1 errors. Inject single errors. Then, inject 10E6 errors, and then 10E-3 errors. What is happening? Take a snapshot.
2- Repeat the step above and inject TSE. What is TSE? Take a snapshot.
3- Change TSE error rate to 10E-9. What happens? Explain your observation.
4- Generate Loss of Frame (LOF STS). Repeat part 1 and explain what LOF is.
D- If we measure BER to be 10E-9 in an OC48 system. That translates to about how
many errors per second on average? Show all your calculations.
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E- Click on Interface Setting. Answer the following questions:
1- What is the rate of indicated STS signal?
2- What type of line coding are you using? What does it mean? Draw it.
3- What is wavelength?
F- Connect the optical transmitted to the Multi-wavelength meter
1- Verify the wavelength. Take a snapshot. Is it what you expected?
2- What is the output power level of the ANT-20E. (make sure the attenuator is
zero to ZERO)
Part V:
A- Make sure the system is working error free. Slowly change the attenuation of the
transmit signal. Using a plot/table identify exactly what happens to error types as
you reduce the signal level. Explain your observations.
B- Connect the TX of ANT-20E to the Optical Filter and send the output of the filter
to the wavelength meter. Change the filter. Explain your observations.
C- Set the signal to general AIS signal. Connect the TX side to the scope. Can you see
the eye diagram? Measure all the jitters.
Part VI:
A- Establish the following electrical connections, assume the DS1 is Framed:
1- Go to ApplicationNew
2- Go to EditSignal Structure
3- Establish DWDS1 (unframe) DUT  DS1 (unframe) DW (define Word)
4- Remove the Coax cable between connections 14 and 15 and make sure you
are getting LOS (loss of signal).
5- Take a snapshot of your network setup
B- Connect the output of pin 15 of the ANT-20 to the Tektronix scope. Go to
INTERFACE menu and make sure the signal is unbalanced, HIGH.
1- Set Code=B3ZS. Set DW=ALL-ones; observe the signal on the scope. Draw a
single cycle of the signal in your report.
2- Set Code=B3ZS. Set DW=ALL-zeros; observe the signal on the scope. Draw a
single cycle of the signal in your report.
3- Set Code=AMI. Set DW=ALL-ones; observe the signal on the scope. Draw a
single cycle of the signal in your report.
4- Set Code=AMI. Set DW=ALL-zeros; observe the signal on the scope. Draw a
single cycle of the signal in your report.
5- Clearly explain the difference between AMI and B3ZS line coding.
6- What will be the difference between an AMI and a B3ZS signal if we are
transmitting 11000000? Show the difference and explain it.
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