6-1.1 Meters required for POI A/T. Any of the following Network Analyzers for Return loss and cable attenuation:-

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1 Chapter 6

2 6-1 General : Meters required for POI A/T. OFC Media, 1. Optical Power Meter any make for Trans power / Rx Sensitivity of OFC system 2. Optical Variable Attenuator any make for do of OFC system Any of the following Network Analyzers for Return loss and cable attenuation:- 3. Anritsu Network Analyzer MS 3401 A 10 Hz-30 MHz with reflection bridge MA 2202 A and transformer 75/ HP Network Analyzer 8751 a 5Hz 500 MHz with bridge. 5. AGILENT Network Analyzer E 5100 A 10 KHz -180 MHz with AGILENT Trans/ Reflection Test set A and 75/120 transformer 6. W & G Network Analyzer PSM -137 with bridge. Any of the following Testers for Pulse characteristics Test:- 7. ACTERNA E1 Service tester EST 125 DB HP digitizing oscilloscope No , 500 MHz 9. AGILENT digitizing oscilloscope No.5430 Any of the following PDH/SDH Analyzers for BER, Jitter, Alarm test and Stability Test:- 10. Anritsu MP 1550 B PDH/SDH Analyzer or MP 1552 A 11. W & G ANT-20 E or ACTERNA ANT-20 SE 12. Meter no ACTERNA E1 and DATA TESTER EDT BER Tester 9 Sunlight E1 by Sunlight Telecom. Any of the following meters for frequency measurement:- 15 HP DTA set A 16 HP Universal frequency counter A/ 225 MHz 17 Anritsu frequency counter Other Accessories:- 18. Printer for BER, Jitter mask printouts. 19. SC-FC, SC-PC, LC-FC Patch cords 20. Moligraph optical fibre cleaner 1/0402 or any other cleaner

3 POI (Point of interface) Acceptance Testing Various Vendors :- At present the following vendors use to offer A/T from T & D Circle, they are:- 1. VSNL 2. Reliance communication ltd 3. IDEA 4. Bharti Airtel Limited 5. TTML 6. Hutch Vendor has to apply for nos. of E1 as required and paying for E1 as per BSNL norms Before A/T :-. POI A/T use to offer in three types which are as follows :- 1. E1 interface A/T. 2. Traffic shifting from passive network to active network i.e. installation of STM-1 system. 3. E1 working on Copper cable with modem, as POP distance is more. A/T starts from the verification of documents which are as follows: - 1. Offering memo 2. Payment details, Advice note, Demand note, 3. Paid receipt ACG Circle representative nomination letter as a third committee member, 5. The trunking diagram of scheme. Verify all relevant documents as above and find out any discrepancy in documents and bring to the notice of vendor. A/T should be carried in the following manner: - 1. Check of documentation. 2. POI Equipment A/T. 3. Stability of E1 on loop from vendors MSC. 4. A/T report signature and forwarding to DET A/T ( Trans ), informing completion of A/T to DET A/T Switching to carry out POI Switching A/T. BSNL STM-1 BSNL OFC CU Cable POP STM-1 POP Fig

4 6-2 Transmission A/T: Transceiver parameters :- The following OFC STM-1 Systems are being installed by Vendor. 1. Tejas 100 CP (8 E1) 2. ECI 3. Nortel First of all check the physical installation of Rack, vertical support/runway at the top of the system, DC power supply distribution through MCB taken or not? 1. To check of Trans power of STM-1 system port-1 and port 2.Connect power meter to port 1 and measure the trans power of port 1 which should be as per following table. Measure trans power of 2 nd port also. 2. Limits are as below :- System Trans power Rec. Overload Sensitivity Tejas 100 CP S1.1 L1.1-8 to -15 dbm 0 to -5 dbm < -28 dbm <-28 dbm -8 dbm -10 dbm ECI -10 to -15 dbm <-33 dbm -13 dbm Nortel +2 to -5 dbm <-28 dbm -8 dbm 3. Receiver Sensitivity :- Prepare the set up of test as below Fig OF System DDF TX RX Patch cards V/ Attenuator EC= 1 SES DTA Set Fig.6-2 Keep Attenuator normally at -20 dbm and observe loop O.K on DTA set. Increase attenuation till you observe EC=1 on DTA set. Disconnect Rx of V/ Attenuator for and connect to power meter so as to get exact sensitivity point. Now go to higher side so as to observe EC=1 and note down the overload point. Repeat same procedure for port 2 also. 4. Check of alarms: - Check and indicate functioning of various audible/ Visual alarms provided on the system as follows :- 138

5 a. Major b. Minor c. Critical For this alarm test, in the above Rx sensitivity set up, further increase attenuation gradually and observe Minor, Major, Critical alarm on system. e.g. In Tejas 100 CP system following are the Minor, Major and Critical alarm that you have to monitor. Minor : - 1. E -6 Major : - AIS, Signal degraded, Excessive Error Critical : - LOS, LOF. 5. Check of DDF: - Check that DDF is crone type or regular at PSTN end is provided,it is inbuilt or wall mounted DDF. If not. then separate DDF should be provided, also verify that DDF is earthed or not? 6. Performance Stability: - After all POI A/T tests are over, System is ready for Stability test. Arrange loop from their nearest MSC, and confirm it by taking disconnection. If whole route is OFC up to their MSC then stability Period is 24 Hrs and any M/W media is involved in between the route, then Carry out stability for 96 Hours. Attach Print out with the A/T report. 7. Safety requirements: - All the equipments like Antennas, Tower, Mast/ pole, Feeder, RF equipment and accessories, check physically for their protection from lightning and similar hazards, also check OF cable, Feeder cable entering in the equipment room is properly protected/ covered/ sealed or not? Wave Guide is properly taken on runway or not? OF cable entry in BSNL MDF is protected or not? ii Mb/S interface. Testing at POI 1. Check of attenuation of interconnecting cable: - By 5100 network Analyzer. Cu cable / PCM Cable connectivity: - Feed 1024 KHz at 0 dbm and measure O/P at distance end, calculate the loss which should not exceed 6 db. 2. OF Cable Connectivity: - Generally vendor used to lay 6F or 12F OF cable for connectivity at PSTN end. OF cable is laid and maintained by them only. So need not to conduct A/T of all 6/12 F. Moreover as they are not offering whole cable for A/T, So only the fibers of interest viz F1, F2 on which system will work, are to be tested. Note down the Trans power of port-1 and port-2 by Power Meter. Go to vendor site with power meter ask PSTN end to send source power and measure Rx power calculate the fibre loss which is to be calculated as below as the distance is always <10 Km a. No. of splice x 0.1 = 2 x 0.1 =0.2 b. FDF loss 0.5 x 2 = 1.0 c x Cable length in Km = d. Total loss = a + b + c e. Limit for Cable loss = d db/km Length of cable 139

6 2. Return loss Measurement at input port (For passive link this test is to be taken) This is to be taken for impedance matching120 Ω between POI. End and vendor site. A] With Agilent Network Analyzer 5100 A. Fig 6-3 Pulse RF OUT 75 Ω R A B HP A Bridge 75 Ω 75 Ω 75 Ω Transformer 120 E1 RX Fig 6-3 Make a test set as shown in the above figure with Network Analyzer and bridge. This test can be carried out by Anritsu, HP, Agilent or by W/G Network Analyzer. Here all four meter s set up is shown and explained, near about procedure is same for all set up except some extra operations of buttons. 1. Meas/format- log mag. 2. Calibration: - Connect Open/short and Load connector done. 3. Select frequencies start enter 51 KHz enter stop frequency 3072 KHz 4. Connect E1 Rx to bridge I/P port and a trace is displayed on screen. 5. Press marker key select all required frequencies one by one and note Down the corresponding reading. B] Return Loss by Anritsu Network Analyzer. - Make a test set up as below Fig Connect E1 Rx to 120 Ω put of bridge section enter start, - Enter start frequency 51 KHz and stop frequency 3072 KHz and observe trace on Analyzer display. - Press scale for offset A, move wheel to centre point= 0 dbm as O/P reference. 140

7 - Calibration X S ON( self calibration) enter - Select frequencies as per table either by wheel or by pressing soft keys. - Note down Return loss reading. - The reading set should be repeated for all offered E1,S. - Readings for example :- 51 KHz 13 db 100 KHz 18 db 400 KHz KHz Limits : KHz 12 db KHz 18 db KHZ 14 db Return loss with Anritsu Network Analyzer:- WHEEL O/P 75 Ω Prob I/P 75 Ω 0 db Max +12V source Max.+20dB I/P 75Ω Prob +12V O/P 75 Ω Anritsu Reflection Bridge MA2202 A Bridge Section 30 Hz-250 MHz Transformer Section Anritsu Reflection Bridge MA2202 A 30 Hz-250 MHz Bridge Section 8 G 120 Ω 20 Ω E1 Rx Fig

8 50 Ω 50 Ω 50 Ω RT out R A Calibration with open/short connector RF IN R A Test port E1 Rx Test Set Bridge Transpower Fig. 6-5 Return loss with HP Network Analyzer:- - Make connections as per diagram between Analyzer, Transmission/Reflection test set and Ω Transformer as shown in Fig Measure/ Format key- Format- More-Log mag, - See yellow trace. - Start- Enter 51- Press X K1 function soft key, - Stop- enter 3072 Press cross K1 from soft key - Press cal- Select 1- port /3 -term from soft menu. - Connect Open connector to test port, - Press, OPEN soft key, - Remove open connector and connect short connector, - Press SHORT - Remove SHORT and connect load 75Ω and Press LOAD -press DONE - Remove load and connect E1 Rx under test through Ω Transpower - Observe, trace on display for 51 KHz in the right corner see loss in db - Tune all the frequencies given in table and note down the loss in db - The Limits and Frequencies are given below: KHz to 102 KHz 12 db 102 KHz to 2048 KHz 18 db 2048 KHz to 3072 KHz 14 db and the frequencies to be selected are 51 KHz, 100, 400, 600, 1000, 1500, 2500, 2600 and 3072 KHz. Return loss with W/G selective level :- Measuring set (PSM-137) with a W/G bridge RFZ-12 - Prepare a test set up as follows, Fig. no Put ON - Press Blue button and set up - Select Ret loss/ Attenuation - Recall, Press red 142

9 W/G PSM KHz Rx 120 Tx Ω 75 Ω W/G RF 2-12 E1 Rx 120 Tx W G Rx Ω 120 Fig Level display , - Press left Ref key and right also, - Ref level goes to zero (Rx level) - Calibration is in built (Auto), - Press right key to select frequency, - Press 51.2 digits by digit key, - Connect E1, Rx to PCM-137 Rx (120 Ω), - Select frequencies as per table and note down the Rx levels, - Compare results with Specifications. 2. Measurement of clock frequency :- - Measure the Trans clock frequency, - Limit : KHz ± 50 PPM (±102 Hz) i.e to Hz Check of Output pulse characteristics :- 1. With HP A Digitizing oscilloscope Pl. see Fig

10 - Make a test set up as below :- Width AMP WHEEL FT RT A11 I/P Pulse width RT 1 FT 75 Ω Fig Connect E1Rx to any one of four input ports, and select any o/o four ports. select 2 for 50 ohms. Press set up. Select frequency start and stop. - Press calibration, open, short, load to perform calibration. - Press marker, marker list. - Press set up and recall-1 for + pulse, Observe + pulse on display. Press 2 for ve pulse. - In the bottom of oscilloscope read Pulse Amplitude and width, Rise and fall time of the pulse. - Note down the readings for corresponding frequency. - Calculate ratios for width and amplitude. - For Rise and Fall time move the cursor, and note reading. - The limits are as below: - Nominal value A. Pulse Amplitude + ve pulse 3.0 ± 0.3 V ve pulse 3.00 B. Pulse width + ve pulse 244 ± 24 ŋs ve pulse 252 C. Ratio of + ve & -ve Pulse amplitude 0.95 to D. Ratio of +ve & -ve pulse width 0.95 to E. Rise time + ve pulse 80 ŋs 28 - ve pulse 30 F. Fall Time + ve pulse 80 ŋs 30 - ve pulse 32 Test with Acterna E1 tester: - See Pulse mask in Fig. 6-8 and tester in Fig Reading for example.. - There are six options, Menu 1 jitter function, E1 pulse shape and level, G826 performance. - Select E1 pulse shape level, Connect E1 Tx and Rx ( on Loop from MSC) - Press more two times set up- E1 pulse- S1- Wait. 75 Ω 120 Ω 144

11 - Select +ve or -ve polarity, Interface 120/ 75 Ω, - Run- Cal O.K Results. Upper mask E1 Lower Mask 500 ŋs - Fig Readings are as follows for example :- - Rise time 55 ŋs, Fall time 37 ŋs - Pulse width 253 ŋs, Overshoot 12 %, Under shoot 80% - Run test for +ve & -ve pulse, - Calculate the ratio as per mentioned table and its limit as - Ratio of pulse amplitude 0.95 to 1.05, - Ratio of pulse width 244 ± 24 ŋs Jitter Test:- Input Jitter tolerance:- - Ask MSC to loop E1, Confirm loop by disconnection. - Connect E1 Tx and Rx to ANT 20 E or any DTA set with jitter modulator. With ANT-20 E: - - Make a test set up as below, - Open jitter generator and analyzer. - MTJ Set MTJ Setting- Select,(Maximum Tolerable Jitter ) - Scan frequencies by keyboard as 20 Hz,93 Hz,700 Hz and 100 KHz in a table, - Enter OK. - Jitter table Start after 2 to 3 minutes reading will start to be displayed, - select Mask run, - Take out print out of jitter table and mask which are shown in the next diagram no 6-9 on next page. 145

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14 Combine jitter and wander from tributary mapping and pointer adjustment (With Anritsu DTA set) The conditions are: - 1. Jitter ON, Wander OFF. 2. Wander ON, Jitter OFF. 3. HP1 + LP 20 Hz- 100 KHz. 4. HP2 + LP 18KHz- 100 KHz. and under following conditions :- 5. a) Single pointer with opposite polarity separated by 10 S (n =1) b) Regular pointer at every 0.75 s plus one double pointer (T3 = 2) with 2 ms spacing (43,44 in ANT-20E ) c) Regular pointers at every 0.75 s with missing pointer. With Anritsu DTA set: - Anritsu 1552 A Optical Electrical T R DDF T R Tx Rx Tx ECI STM-1 Rx Fig Make connections between DTA set, STM-1system and DDF as per above diagram. - Mapping for optical to electrical to be done in laptop. - Observe loop on DTA set- Select pointer sequence / filters and Jitter/ Wander ON - Note down the results as given below in the table for example: - - Results are for examples only with limits: - F1-F4 (20 KHz-100 KHz) F3-F4 (18 KHz-100 KHz) Jitter ON Wander OFF a UI a UI b UI b UI c UI c UI Wander ON Jitter OFF a UI a UI b UI b UI c UI c UI Limit: UI UI 148

15 6-2.8 If POI is offered on PCM cable then test PCM cable attenuation. Limit :- 6 db at 1024 KHz. If connectivity between BSNL and vendors POP up is provided by copper cable with Modem then, ( See Fig ) - Chapter 4B measurement is not applicable. - Crone box termination and earthing to be checked. - Stability to be taken 24/ 96 as per onward media connectivity up to their MSC. - Safety measurements like GD tubes proved or not? - Attenuation test as Modem is provided, need not to take. - Return loss Measurement as described earlier. - Check of O/P pulse characteristics: - as described earlier. - O/P jitter, I/P jitter tolerance and Mask to be taken as mentioned earlier with print outs. - End to End BER as usual to be carried out with loop from their MSC. - Jitter and wander not applicable. - Make one visit to vendor POP up and check their onward media. POI A/T on Cu wire Modem loop Loop Telecom loop-4 X DSL Loop- 4 TM 3900 Tx out Rx IN TAX/OCB Rosette cord Loop Telecom 2048 Kbps Line Console MODEM Rosette crone R termination B R B LED s loop R B R B Modem ON or remote supply MDF Cu Cable 0.9 mm VSNL POP (Module) Existing M/W on OFC System E1 Fig

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4. CDMA (WLL) BTS A/T

Chapter 4 4. CDMA (WLL) BTS A/T 4-1 General: - There are two CDMA WLL systems introduced in BSNL these are: - 1 STAREX-WLL from LG for rural and urban, South Korea. 2. ZTE/ITI (UTL), Zing Tao Electronics,