1. DTS Migration to Digital Microwave Digital Fundamentals Testing Applications Making the Change

2. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Seminar Objectives Review Digital Microwave Parameters Digital Overview Digital Test Equipment Overview DSX Panels and Standards Digital Test Patterns Digital Errors and Alarms Digital Loopback

3. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Single VF Channel

4. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Baseband Elements The Analog Basebands consist of –Baseband amplifiers –Baseband bridges –Roofing filters –Group converters –Pilot stop filters –Orderwire and Service Channels –Alarm and control devices

5. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Analog and Digital Signal Processing An analog baseband is the composite of all –Voice and HF tones –Noise in each channel –Cumulative system noise Analog means Amplify

6. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Digital Interfaces T1 – DS3 Interface –Interconnection into a digital radio –Conform to ANSI standards –Use Standard DSX Panels Layout Wiring protocol Making a cross-connect

7. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved North American Digital Hierarchy DS04KHz – 1DS064Kb/s DS124 – DS01.544Mb/s DS3 (STS 1) 672 – DS045.736Mb/s (51.840Mb/s) OC3 - Optical (STS 3) – Elec. 2016 – DS0155.220Mb/s OC128064 – DS0622.08Mb/s OC 4832,256 – DS02488.32Mb/s OC192129,024 – DS09953.28Mb/s

8. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved RF Carriers Radio Frequencies (RF) are defined as: –Periodic waves capable of traveling thru space. –Waveforms that meet the conditions of Maxwell’s Equations. –Always periodic electro-magnetic wave fronts. –Always consist of three core elements...

9. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Modulation RF carriers exist as CW with no external modulation – variation. To Modulate is to vary, such as: –Change Amplitude –AM –Change Frequency – FM –Change Phase – Ø

10. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved CW Wave

11. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved FM Modulation When a carrier is frequency modulated the following occur: –The frequency changes –The amplitude in the fundamental carrier changes. –Multiple sidebands now have carrier power –For Example...

12. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Bessel Null Plot

13. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Baseband to RF After signal combination the following occur: –Passage through Pre-emphasis –Modulation of RF carrier FM Typical PM Possible

14. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Pre-emphasis & De-emphasis Networks

15. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Modulator Analog Radio 75 -25 dBm Frequency Synthsizer BB TEST IN 30 dB -55 dBm Antenna Monitor -30 dBc +30 dBm (+24 dBm Optional) WG CMR 137 Antenna Coupling Unit -20 dBm HF Signal Pre-emphasis Composite TLP Modulation Here Antenna Coupling Carrier Osc.

16. DTS Digital Microwave Digital Systems Digital Transmitters Digital Receivers

17. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Typical System Configuration

18. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Digital Transmitter Digital Transmitters contain the following: –Pulse input equipment (I/O Interface) Pulse Conversion TDM Mux for multiple signals LBO –Band Pass Filters – BPF –RF Carrier Source Oscillators –I and Q splitters –Summing Amplifiers –Power Amplifiers

19. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Digital Transmitter Block

20. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved QPSK Modulator Diagram

21. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Digital Modulation Modulating Steps –AMI/B8ZS to NRZ Conversion –Data Line Splits I-- Lines Q– Lines (Quadrature 90° phase shift) –Mixing with Source Oscillator –Summing Combined RF Signal –FCC Mask Filter –Example..\Microwave Course\QAMGIF.gif..\Microwave Course\QAMGIF.gif

22. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Signal Processing DS1 Signals arrive at Modem (I/O) as –AMI –B8ZS –1.544mb/s / T1 DS3 Signals arrive at Modem (I/O) as –B3ZS –44.736mb/s / DS3 OC3 Signals arrive at HLM on Fiber @ –155.220mb/s

23. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Signals Change Signals are converted to NRZ signals Signals are passed thru a LPF

24. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Simple Digital Modulation Techniques

25. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved 4-Level Digital Modulation

26. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved QPSK Pattern

27. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved I & Q Vector Values 16 QAM Change Amplitude Change Φ

28. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Phase & Carrier at 64 QAM 4 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 +7L +5L +3L +L -L -3L -5L -7L -7L-5L -3L -L+L +3L+5L+7L I Q

29. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved 128 QAM Phase Amplitude

30. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Bandwidth Efficiency 128 QAM

31. DTS Microwave Power Amplifiers Amplifier Characteristics Amplifier Distortion Amplifiers as Oscillators

32. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Microwave Power Amplifiers ATPC – Controls the Power output RSL at Receiver drives ATPC

33. DTS Microwave Receivers Receiver Elements Receiver Process

34. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Receiver Characteristics Receiver Selectivity Receiver Sensitivity The RSL Curve The Digital Carrier –Carrier Recovery –Timing Recovery

35. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Conventional Receiver Most Receivers use IF sections

36. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Direct Conversion Receiver Typical of MDR 6000 Radio Bandwidth restricted

37. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Digital IF Sections The digital IF section performs: –Equalization –Interference suppression –Signal stability

38. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Radio Link Multi-path Characteristics

39. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Multi-path Distortion

40. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Carrier Recovery Threshold for 10-6 BER Rate Ability to detect incoming carrier –Effects of SSBSC Modulation –Local Source Oscillator – Locking signal –Pulse Timing Recovery

41. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Data Recovery Receivers detect and reconstruct original data –Block Coding Reed-Solomon Galois Hamming –Convolution Code

42. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Error Detection There is a difference between Detecting an Error and Correcting an Error –Common errors detected are: CRC BCH Bit Errors

43. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Forward Error Correction (FEC) Common methods of detecting and Correcting data bit errors are: –BCH used in most SCADA applications –Reed-Solomon A Block Code Uses Parity checks

44. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Reed-Solomon Codes Capable of Correcting a Single Error Symbol. Similar to BCH Error Codes Used in Harris Constellation Radio Is Considered a Block Code

45. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved The Eye-Pattern True status of pulse recovery Determines jitter in timing circuit Determines Inter-symbol-Interference (ISI)

46. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Eye Pattern

47. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Single Sweep of Eye Pattern

48. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved The Terminal ACU The Antenna Coupling Unit –Circulates the TX and RX Signals –Isolate the TX from the RX –Protects amplifiers and filters

49. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Antenna Coupling

50. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Network Management Digital networks are often managed by a central system Internet Management Protocol (SNMP)

51. DTS Testing Applications Testing T1 Circuits Test Set Operation Test Patterns Error Reporting

52. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved DSX1 Panel Purpose of the DSX1 Panel –Interconnection Terminates a Single Piece of Equipment Cross-Connects Two Pieces of Equipment –Monitor Access TLP = -20DB Level is dBdsx 432Ω Isolation

53. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Terminating T1 Spans Test Equipment terminates the circuit as follows: Bridge = > 1000Ω Term = 100Ω DSXMON = 100Ω/Gain Signal Level typically: 6v P-P = 0dBdsx Z L = 100 Ω

54. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved LBO in Radio

55. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved T1 Configurations 4 – T1 Radio T1 #1 T1 #4 LBOLBO T1 #2 T1 #3 M12 I/O Each T1 Has LBO Setting

56. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved The 28 T1 Radio Constellation

57. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved DS3 Microwave Interface Up to 3 DS3 Signals can be Connected Data Rate can Interface to OC3 Fiber and Copper make a Connection DS3-DSX Panel Connections The DS3 Copper Connection –RG59

58. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Typical DS3 Interface M13 Mux DS3 Radio optioned for 1 to 3 DS3 Channels

59. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Constellation DS3 Terminal

60. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Digital Overview T1 Framing T1 Line Codes T1 Timing T1 Signal Levels

61. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Network Elements DSX Panels – T1 and DS3 Electrical T1 Devices –Channel Banks –NIU’s to Telco Network –CSU –FT1

62. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved DS3 Overview Channelized Vs Unchannelized M13 Mux –Low Speed –High Speed Electrical Interface – DS3 & STS Optical Interface – T1 to OC-192

63. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Test Equipment Setup 1ST What to Test

64. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Test Signals Test Pattern REPLACES Traffic on T1 Span... INTRUSIVE

65. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved Common Test Patterns All Zeros – AMI/B8ZS Provisioning All Ones – Copper – Max 1’s 3 in 24 – Stress to AMI Circuits –Minimum 1’s density 1/8 –15 Consecutive 0’s QRSS – Voice = average 1’s

66. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved T1 Errors 4 types of T1 errors: –BPV Errors, always on Copper –CRC Errors, always in ESF Framing –Framing Errors, 100% Accurate –BIT Errors – Out of Service Test

67. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved T1 Alarms Core Alarms –Red Alarm – LOS –Yellow Alarm – typically remote alarm

68. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved AIS Signals Alarm Indication Signal (AIS) –Unframed All 1’s –Available in most Terminal Equipment –Maintains Framing

69. DTS Dover Telecommunication Services, Inc. © 2002 All rights reserved T1 Loopbacks Available in most Terminal Equipment –Coastcom Mux –Microwave Radio –Digital Cross-connect (DCS) –CSU –NIU