8/13/2019 Lesson 03 - docs

1/3

Utilization of SDH analyzerPortable analyzer Victoria SDH/SONET/PDH by Trend Communications is equipped with

colour touch screen LCD display for representation of results and for direct selection of all parameters.Display represents graphically block-by-block function of equipment, that is used for transmission ofselected dataflow (from the right side to the left side) and for receiving of signal (from the left side tothe right side). Typical example is shown at next picture (see fig.1). Required parameters are possible toadjust at display by pressing relevant parts of transmission system.

1 - Operating mode/hierarchy2 - Bit rate & Rx code3 - Number (K-L-M) of tributary4 - Number of Rx tributary (163)5 - Number of Tx tributary6 - Rx pattern

7 -

Coupled/Uncoupled8 - Tx pattern9 - OH channel selection for BER

10 - Rx/Tx indication11 - Structure: C-x or PDH map12 - Scrambler enable/disable13 - Mapping type14 - Background pattern15 - Navigation buttons

16 - Tx frequency offset17 - Tx clock source

18 - Enable/disable the laser19 - Bit rate & Tx code

Fig. 1 Display adjustment - typical example

SDH/SONET multiplexer and demultiplexer testsPDH/ANSI T_Carrier signals are carried in synchronous networks as the payload of

SDH/SONET signals. This makes for synchronous multiplexing and demultiplexing in thetransmitting and receiving ends of the circuit. These two operations have to be checked, if we wish toguarantee proper operation. In other words, the correct mapping of the signal in the container/actualpayload capacity should be tested in the multiplexing process, while in the demultiplexing operation;the payload must be correctly recovered.

8/13/2019 Lesson 03 - docs

2/3

Mapping can be easily tested by simply generating the correct payload with a frequency offset. Victoria SDH/SONET/PDH provide two specific modes: the SDH/SONET multiplexer test ( Mux )and the SDH/SONET demultiplexer test ( Demux ), which are especially designed to perform such testsand are widely accepted in the installation and bringing-into-service of SDH/SONET networkelements.

Fig. 2 Multiplexer and demultiplexer with SDH ADMs muldex

Monitoring of multiplexer function

1. Select at touch screen menu Setup/ Configuration at the right side. You will see some block scheme.Press the button in block Mode (1 see fig.1) at the left side and after select mode of measurement

Mux at bottom list.

2. Adjust structure of receiving signal STM-1 (Rx) at bottom side ( Structure: PDH (11 see fig.1) , Mapping: C-12/AU-4 (13 see fig.1)). Display in detail multiplex scheme by pressing button MapRx at the left-bottom side.

3. Generate dataflow in the form PRBS 2 11-1 (8 see fig.1) (E1 2048 kbit/s) with internal clocksource (17 see fig.1) without framing ( Frame: None ). Enter the time location (K-L-M) 1-1-1 of thetributary signal in the signal STM-1 for receiving (TUG3-TUG2-TU12).

4. Connect analyzer optical input to the link port LP 2.1 of muldex and connect analyzer output(OUT) to the muldex tributary port E1 by the help of balancing reduction (see fig.2a). Selectinstead of link code CMI external optical module ( External (2 see fig.1)).

5. Display and record status of indicators (red alarm) in menu LEDs current at the right side andcheck the correct receiving.

6.

Select twice menu Results at the right side and select item SOH POH. Record signification andconcrete capacity main bytes of overhead (RS-OH, MS-OH, LO-POH).

Monitoring of demultiplexer function

1. Select at touch screen menu Setup/ Configuration at the right side. You will see some block scheme.Press the button in block Mode (1 see fig.1) at the left side and after select mode of measurementDemux at bottom list.

2. Adjust structure of sending signal STM-1 (Tx) at bottom side ( Structure: PDH (11 see fig.1) , Mapping: C-12/AU-4 (13 see fig.1)).

3. Restore dataflow in the form PRBS 2 11-1 (6 see fig.1) (E1 2048 kbit/s) with internal clocksource (17 see fig.1) without framing ( Frame: None ). Enter the time location (K-L-M) 1-1-1 of thetributary signal in the signal STM-1 for sending (TUG3-TUG2-TU12).

8/13/2019 Lesson 03 - docs

3/3

4. Connect analyzer optical output to the link port LP 2.1 of muldex and connect analyzer input (IN)to the muldex tributary port E1 by the help of balancing reduction (see fig.2b). Select instead oflink code CMI external optical module ( External (2 see fig.1)) and switch on the laser (ON).

5. Display and record status of indicators (red alarm) in menu LEDs current at the right side andcheck the correct receiving.

Fig. 3

Scheme for analyzing pointers function

Function analysis of pointer

1. Select at touch screen menu Setup/ Configuration at the right side. You will see some block scheme.Press the button in block Mode (1 see fig.1) at the left side and after select mode of measurementSDH/SONET Path at bottom list. Generate dataflow at structure PDH E1 to VC-12 ( Structure:PDH , Mapping: VC-12 , Tx Rx ) with internal clock source (17 see fig.1) and with initialfrequency deviation 0 ppm (16 see fig.1).

2. Scheme is shown at fig.3. The optical analyzer output of STM-1 (transmission part presentsmuldex A) is connected to the link port LP 1.1 of add-drop muldex B and link output is connected

to the optical analyzer input of STM-1 (receiving part presents muldex C). Muldex B is adjusted tothe internal clock source with frequency f 2 (Free Running Mode).3. Analyze stuffing at container VC-12, which is switched from the time location 1-2-2 to the time

location 1-2-3 in terms of transmission system. Check the correct receiving.4. Select twice menu Results at the right side and find out pointer value ( Pointer values ). Adjust pointer

values 0 for AU-4 and TU-12 at transmission side ( Transmitted ), then record pointer values AU-4and TU-12 at the receiving side ( Received ).

5. Select twice menu Results at the right side and find out stuffing in dependence on frequencydeviation of generated signal STM-1 with frequency f 1 ( Pointer events ). Measure at 10 secondsintervals by the help of button Start/Stop for frequency deviation 0, 1, 5, 10, 20, 50, 100 and200 ppm. Make graph from recognized values.

6. Find out frequency variation for clock source of analyzer that is derived from receiving signal ( Rec ).

Monitoring of bit error rate (BER)

1. Select at touch screen menu Setup/ Configuration at the right side. You will see some block scheme.Press the button in block Mode (1 see fig.1) at the left side and after select mode of measurementSDH/SONET Path at bottom list. Generate dataflow at structure PDH E1 to VC-12 ( Structure:PDH , Mapping: VC-12 , Tx Rx ) with internal clock source (17 see fig.1) and with initialfrequency deviation 400 ppm (16 see fig.1).

2. Press Start button and display error events in menu Results/Error and results of monitoring of biterror rate (BER) in menu Results/Performance . Introduce meaning of all error parameters and

measured values over 20 seconds.