ALC PDH RADIO Technical Training(Siae Microwave)

ALC PDH RADIO Technical Training Instructor Mr. Monthien Satantoranin Senior Manager Technical Support ALC

1

Training Topics 1. 2. 3. 4. 5. 6.

ALC

ALC Equipment Structure Installation , Configuration and Operating SCT Network Management Faults and Alarm Understanding Troubleshooting and Looback Test Path/Link Calculation

2

ALC Equipment Structure 1. 2. 3. 4. 5.

ALC

ALC IDU ( Indoor Unit) ALC ODU ( Outdoor Unit) LIM ( Line Interface Module) RIM ( Radio Interface Module) Interconnection IDU to ODU cable

3

IDU ( Indoor Unit)

Mains Features Max capacity : 16 E1 + 3 Ethernet Port IDU size: 1U high only and single board Service channel: optional V11 codirectional. Loops: RF loop, IF loop and Baseband loops ATPC range : depending on frequency (20dB or 40 dB) Internal PRBS IDU-ODU cable: 370 meter of ¼” or RG8

ALC

4

IDU (Indoor Unit) SCT LAN port 120ohm E1 Sub-D type connectors

LCT USB connector

PSU connector Trib. 1-2-3-4

Q3

LCT

PSU alarm LEDs

Trib. 9-10-11-12

48V2

48V1

USER IN/OUT

PS1

TX RX 1 2 Trib. 13-14-15-16

-

PS2

Manual operation / Loop active Fuse: 3.15A (M)

Tx Rx R

TEST

1

AL

2

+

2 Trib. 5-6-7-8

+

TEST R AL

1

2

-

IDU-ODU cable SMA connectors

Reset Alarms ALC

Active branch (Tx / Rx)

5

Reference Tooth

Volt/dBm in Rx Weight = 4.5 Kg

ODU (Outdoor Unit) ALC

6

ODU Mounting

Max.1 dB Loss ALC

7

ALC

8

ODU with Integrated antenna

1+1 ODU

1+0 ODU

Unprotected ODU ALC

9

Interconnection cable Frequency signals:  Tx IF  Rx IF  Telemetry IDUODU  Telemetry ODUIDU  Power 48 VDC

330 MHz 140 MHz 17.5 MHz 5.2 MHz

Max length (1/4 inch or RG 8 cable)  4/16QAM

ALC

370 m 10

Equipment Composition ALC is made up by different sub-modules housed in two mechanical structures: 1) IDU   

LIM Controller RIM (one per branch)

2) ODU 

Radiotransceiver (RT, one per branch)

ALC

11

Module functionalities Line

interfaces

Line

Mux-Demux circuits, Service Mux-demux circuits

Bit

insertion-extraction,

Modulator Switch BER

LIM

- Demodulator (digital side)

management

counters

Power

supply

Cable

interface

Modulator

RIM

(analog side) 330 MHz

Demodulator

(analog side) 140 MHz Radio

Power supply

Cable

interface

IF

ALC



Service interfaces



Management software ports



Equipment controller



EOC



Alarm LEDs



User in / Alarm out facilities

CONTROLLER

RT

unit

RF

unit: Transmitter, Receiver

12

Equipment structure ALC

13

Controller

ALC

14

)

ALC

LIM

Tx direction

15

LIM

Rx direction *FEC = Forward Error Corrector Example: FEC *

Without  BER=10-6 With  BER=10-13

(+2.5 dB)

(block code)

errors

ALC

16

RIM

ALC

17

ODU

ALC

18

ALC characteristics (1)  Tx

power (4QAM/16QAM): 7 GHz +27 dBm / +22 dBm 15 GHz +25 dBm / +20 dBm 23 GHz +20 dBm / +15 dBm

 Tx/Rx

spacing: 7 GHz 154/161/168/196/245 MHz 15 GHz 420/728 MHz 23 GHz 1008/1232 MHz

 Power

1+0 1+1 ALC

consumption < 30 W < 55 W

19

ALC characteristics (2)  Rx

HBER (10E-3) thresholds (4QAM/16QAM): - in 16x2 7 GHz -84 dBm / -80 dBm 15 GHz -83.5 dBm / -79.5 dBm 23 GHz -83 dBm / -79 dBm - in 4x2 7 GHz -90 dBm / -86 dBm 15 GHz -89.5 dBm / -85.5 dBm 23 GHz -89 dBm / -85 dBm

 Max ALC

Rx power

- 20 dBm 20

Installation ,Configuration and Operating 1. 2. 3. 4. 5. 6.

ALC

IDU, ODU Installation SCT :Network Management Software LCT :Local Craft Terminal Parameter and Configuration Alarm Monitoring Backup ,Upload and Download firmware

21

Installation  IDU

Installation  Power Supply and Grounding  E1 Cable and Wiring  Antenna and ODU Mounting

ALC

22

Installation  IDU

Installation (1) USB/LCT E1 Power Supply IDU to ODU Cable

ALC

23

Installation  IDU

Installation (2)

IDU to ODU Cable

ALC

24

 Power

Installation

Supply and Grounding Power Supply -48 to -57.6 Vdc Nominal Consumption 44 watts (1+0) 24 watts ( IDU only)

ALC

25

Installation  Power

Supply and Grounding

1= IDU grounding point

5=IDU matching tail grounding

2=ODU grounding point

6=Battery grounding point

3= IDU-ODU interconnect cable 7=Grounding cord connect to Earth ground rod 4=Cable grounding/Station ground ALC

26

Installation ODU Grounding

ALC

27

Installation  E1

ALC

Cable and Wiring

28

Installation  Antenna

ALC

and ODU Mounting

29

Installation  Antenna

ALC

and ODU Mounting

30

Installation Antenna

ALC

and ODU Mounting

31

Installation  Antenna

and ODU Mounting

ODU final housing position for

ODU final housing position for

Vertical Polarization

Horizontal Polarization

ALC

32

Antenna and ODU mounting 1

4

ALC

3

2

5

6

33

SCT/LCT : Main Features  SCT/LCT

connection  SCT Main Window Menus  Routing  Stored Routing Table  Station management  Commang Logger  Equipment features management  Configuration backup/restore  Alarm monitoring  LCT Main Window Manus  Radio Parameter Configurations ALC

34

SUBNETWORK and LOCAL CRAFT TERMINAL SCT/LCT

PERSONAL COMPUTER WITH GRAPHICAL DISPLAY WINDOWS 98, NT, 2000, XP SW PLATFORM TCP/IP COMMUNICATION PROTOCOL USING: RS232 Serial port (COM1/2 + PPP) USB +PPP Ethernet LAN

ALC

35

“ALC” RADIO IP PROTOCOL STACK APPLICATION SOFTWARE SNMP TCP / UDP IP / OSPF LLC 802.2 MAC 802.3 802.3 (ETH LAN)

ALC

PPP LCT USB

EOC (Radio) 64Kb/s

ASYN-RS232 57.6Kb/s

36

SCT : Connections

C

ALC

37

Connection to the equipment

ALC

38

Login

User: SYSTEM Password: ALC

(read & write) ; RLOM

(read only)

siaemicr 39

Stations

Equipments inside the station

lo y r o Hist

ALC

g

40

Read again the status of the equipment

User management and time alignment

Configuration upload/download and station management

Configuration of the equipment Log as SYSTEM an equipment in monitor

History log management

Configuration of the connection

list of commands

ALC

41

SCT Menu-Equipment

ALC

42

SCT Menu-Option

ALC

43

SCT Menu-Network

ALC

44

SCT Menu-Tool

ALC

45

Equipment menu

Equipment configuration Agent, name, time Alarms, group by group Alarms’ configuration Test, loops, manual operations Alarms reading (refresh) Firmware update Performance monitoring Units Automatic troubleshooting Routing and addressing

ALC

46

ALC

47

Properties Equipment name Agent, used in alarm history and in subnetwork wizard Equipment time alignment and network time alignment Software restart (doesn’t cut the traffic)

ALC

48

View Current Alarms

ALC

49

Alarm configuration

ALC

50

Manual operations list

ALC

51

Firmware Update Firmware Switch Download of the firmware

Upload of the actual firmware

ALC

52

Download of the new firmware Position of the file firmware.dwl

Overwriting of old firmware (total dowload – slow) Download of different sections only (fast) or towards peripheral (radio) Bench switch after the download ALC

53

Performance Monitoring

Start/Stop of selected item

Quality results Output power Input power

ALC

Show of the results of the selected item

54

UNITS

Part number

Part number

Status

Kind of trouble ALC

Trouble severity 55

Diagnosis Reading the actual alarms the Diagnosis prepares an explanation of every trouble and the procedures to follow to solve the problem

ALC

56

Port addresses All SIAE equipments, regarding SCT software and supervision, are routers: all interfaces need an address and relevant subnet mask

Addresses can be set clicking: 1.

Set values

2.

Store

3.

Restart

Client (always) ALC

57

Routing

ALC

58

Routing ALC Port and Address

ALC

59

Routing ALC Port and Address in daisy chain

ALC

60

Routing table Type and address of crossed port towards Destination

Netmask and IP address of Destination Type and address of crossed port Default destination ALC

61

Stored Routing Table The “Stored Routing Table” adds routing lines, after a Restart, to the running Routing Table of the NE. In this way we can change Ports addresses (operation that needs a restart) without loosing a remote NE: 1. In “Stored Routing Table” add the routing lines relevant to new port addresses you are going to set 2. Set the new port addresses (…the equipment restarts) 3. After the restart the equipment has new addresses and the routing table configured already: the NE management is still running

ALC

62

Station management NEs connected to SCT can be assigned in various stations using the tool : “Subnetwork Configuration Wizard”

ALC

63

Alarm correlation Every alarm is reported with  Alarm beginning  Alarm end (gravity info is maintained)

ALC

64

Alarm acknowledgement Alarm acknowledge is available in  alarm history list: every acknowledgement can be managed completely  in station list: new alarm info is highlighted by an asterisk

ALC

65

Command logger Cmd Logger reads the list of operations, executed by the users, stored on the controller of the equipment. The “log”, uploaded from equipment, is stored on the PC for further consultations. Following filters are available:  Operations date  User address  User type  Operation name

ALC

66

Configuration upload/download Upload (from equipment) From

Tool menu, open the proper Template Select Upload operation and the equipment you want to upload information from Save them in a file (*.cfg)

Download (to equipment) From

Tool menu, open the proper file (*.cfg) Select Download operation and the equipment you want to download information to Uploaded parameters and *.cfg file are editable using Equipment Configuration Wizard. ALC

67

Configuration Template Configuration

template: it is relevant to equipment radio parameters as frequency, attenuation, capacity, thresholds,… Address

configuration template: it is relevant to management parameters as port IP addresses, routing tables, remote elements tables, OSPF. Both configurations are necessary during first installation or when Controller module is substituted with a spare one: you can use a file to download or set every parameter manually. ALC

68

Full backup The whole amount of parameters (equipment parameters, address parameters and remote element table) can be uploaded from equipment, saved in a file (*.bku), downloaded to equipment. These parameters cannot be editated.

ALC

69

LCT for ALC

ALC

70

Configuration

General Bitrate

Modulation

Link ID (local only)

ALC

71

Rx Power Low thresholds

HBer,LBer, EWL thresholds

ALC

1) General preset: thresholds 72

2) General preset: Rx switches

1+0 1+1

In case of no Rx

In case of Hber, Lber, EWL, first CRC correction ALC

73

Radio link parameters Main parameters of the link are: Configuration Capacity

For local Modulation terminal

Setting has to be copied in remote terminal

Link ID Frequency Frequency

For both Only “Configuration” Capacity local and has to be set locally (on Modulation remote local and after on terminal remote) Link ID ALC

74

PRBS (Pseudo Random Bit Sequence) Measure results and duration

Alarm on “Checked signal” line

Sync Los events during test Measure status Pattern type

Checked signal selection

Tributary selection if checked is Signal 2MBit

P.R.B.S replaces the traffic on selected channel P.R.B.S. test is pointed out as Manual Operation (subject to timeout) ALC

75

ATPC (Automatic Tx Power Control)

ALC

76

ATPC Characteristics Maximum ATPC range:

This range is limited by the amount of fixed attenuation with respect to the nominal TX power

Power Control Criteria:

Remote terminal Received Signal Level (RSL) and BER

ATPC speed:

30 dB/s

Purpouse:

To counteract the effect of flat fading, minimizing nodal interferences

ALC

77

Maintenance 1. 2. 3. 4. 5.

ALC

Reriodical Check Alarm Meaning Root Cause of Failure Troubleshooting Loop Facilities

78

Periodical Check Periodical Checks are used to check for radio equipment operation without the presence of any alarm conditions 

Check of the TX Power



Check of the Receive Signal Strength ( Reading Value must be match with link hop Cal.)



ALC

Check of BER and HOP performance

79

Normal operating condition

Rx level on both ODU match values given by hop calculation. Rx level accuracy:  -40

dBm -75 dBm range  -30 dBm -40 dBm range ALC

± 3dB ± 4dB 80

Faulty condition: alarm notification A faulty condition is pointed out by  IDU front panel LEDs: - AL: alarms, internal or external - TEST: manual operation active  SCT

window:

- Log history area (with alarm correlation) - Equipment view current alarms (with alarms grouping)

ALC

81

ALARMS There are two directions of alarms: Tx and Rx Tx

– This line starts in LIM and arrives to output flange: when a situation of more alarms is occurring, the most significative alarm of them is at the beginning of Tx chain, all the others after are due to this Rx

– This line starts in output flange and arrives to LIM: when a situation of more alarms is occurring, the most significative alarm of them is at the beginning of Rx chain, all the others after should be caused by this

ODU

Rx Most Significant alarm

RIM LIM ALC

Tx

ODU RIM LIM 82

COMMON group Alarms not related to a specific part of the equipment but relevant to the link. Example:. – EOC radio alarm (relevant SCT management) – Link telemetry fail (relevant traffic, ATPC info, man op) If both alarms are ON, the link is interrupted. Investigation must be made on a possible condition of bad propagation, or equipment failure

ALC

83

ALC

84

Link telemetry fail No link between Local and Remote station. Traffic is cut. Link telemetry is inserted in main radio frame in Bit Insertion circuit inside LIM, and contains commands for the remote station: switch off the radios on remote side in case of local RF loop, Link ID, ATPC info. Telemetry link is a connection between local and remote IDUs. TEST - if this alarm occurs, a double IDU loop (both branches) can be done: if this alarm disappears, local IDU is OK and the problem is after (propagation, local radios, remote equipment).

ALC

85

Communication Radio EOC Data link No link between Local and Remote station or wrong port address configuration. EOC is the channel involved in management communication. If EOC radio link is active: - Traffic is OK - Management is cut (no remote)

ALC

86

PRBS Fail When PRBS is working and no signal is received on checked signal, in PRBS window the field Sync Los Alarm is active together with PRBS Fail in Current alarms window Every ON-OFF transition increases the field PRBS Fail Alarm Counter

ALC

87

Communication 2Mb EOC Data link No EOC channel is present on selected tributary in selected timeslot : wrong port address configuration or no tributary input (LOS). EOC is the channel involved in management communication. If EOC 2Mb link is active: -Management is cut (no remote) - If relative LOS is active, traffic on that tributary is cut

ALC

88

Revertive When a branch is declared preferential, the switch on opposite branch gives Revertive alarm. The return to preferential branch, when available again, happens after “Wait Time” period.

ALC

89

2Mb/s G.704 (Trib.x) Radio Fail/AIS and/or Line Fail/AIS When management messages come via tributary timeslot, further checks are performed on both directions of this tributary

ALC

90

Tx Fail When on remote side both radios don’t receive, on local side a Tx switch command is performed and Tx fail alarm is enabled. When this alarm is on, check local ODU in stand by This functionality is enabled in LCT – General Preset The alarm remains active until Reset is given

ALC

91

Link ID Alarm is on if Link ID check is enabled (Link ID ≠ 0) and remote Link ID is different from the local one. Traffic is cut but signal is received and measured. Output = AIS This alarm causes:

ALC

92

LIM group These alarms come from  External fault: tributary LOS  LIM failure: -Multiplexer/demultiplexer failure -Modulator/demodulator failure Warning: modulator/demodulator circuitry is spread into LIM and RIM modules.  RIM or ODU alarms propagation (seen in LIM as Baseband RX alarm) ALC

93

ALC

94

Tributary-1 Signal loss

Tx

Loss Of Signal alarm is active when a situation opposite to that foreseen by configuration is performed on tributary interface: No input or or cable disconnected TRIB. STATUS

Tributary connected

ALC

95

Multiplexer fail

Tx

The alarm is given during multiplexing of input tributaries by 

Overflow stuffing memories

Overflow is due to bad clock of one tributary (too fast: >+50ppm) or hardware failure In case of Multiplexer Fail the signal forwarded to the radio is N x AIS (from all the N tributaries)

ALC

96

Branch-x Modulator Fail

Tx

This alarm is active when at cable interface Tx IF modulated signal (330 MHz) is missing or is under a certain value; this is due to:  Modulator faulty Cable IDU-ODU open (that produces high VSWR value) 

Traffic is cut

ALC

97

Branch-x ODU-IDU Communication fail This alarm occurs when on carrier used to receive information from ODU, or remote commands from other side, are detected: 

CRC errors



Loss of frame

This carrier is separated from carrier used for opposite direction (IDUODU) and from TX or RX carriers

ALC

98

Branch-x Demodulator Fail

Rx

This alarm is active when average deviation of symbol recognition is higher of a certain level. Every problem in constellation gives Demodulator alarm: Problem of digital conversion of received signal from RIM  I or Q signal missing  High level of interference (bad quality but good Rx level)  No Rx IF modulated signal (140 MHz) from ODU (no Rx, ODU faulty, IDU/ODU cable open) Branch Rx quality alarm 

Demodulator alarm causes:

(software settable)

Rx quality alarms (HBER, LBER, EWL) Rx signal alarms (BaseBand Rx)

Traffic is cut ALC

99

Branch-x BaseBand Rx

Rx

This alarm is active when 

Bit Extraction does not work (in LIM)



Demodulator does not work (in LIM)



Demodulator does not receive from RIM or ODU

BaseBand Rx causes: Demultiplexer Fail

Traffic is cut

ALC

100

Demultiplexer Fail

Rx

The alarm is given during demultiplexing by: 

Frame Alignment Word not recognised (LOF - loss of frame)



Overflow destuffing memories



Overflow memories of hitless Rx switch



BaseBand Rx alarm

In case of Demultiplexer Fail, output is AIS (from all the tributaries)

ALC

101

RIM group These alarms come from  External fault: demodulator fail alarm and ODU alarm are generated when ODU becomes faulty  RIM failure: PSU alarm with cable open/short alarm or modulator/demodulator alarms are active Warning: modulator/demodulator circuitry is spread into LIM and RIM modules.

ALC

102

ALC

103

Branch-1 Power Supply This alarm is active when the PSU (Power Supply Unit) of one RIM is switched off or is in failure condition

Analysis order is:

PSU

IDU

All alarmed from now on

RT

If the PSU is off, all the alarms of that RIM are activated: this alarm causes all Rx Branch-1 alarms except those relevant Radio1 (is OFF)

ALC

104

Branch-1 Cable open/short This alarm is active when the following situations occur: - Cable open alarm  no current through cable interface: ODU is not supplied… so situation looks like PSU alarm (Rx alarms) with cable alarm instead PSU alarm - Cable short alarm  overcurrent/low voltage through cable interface If both alarms are active, 48 V source has no enough current

Caused by high VSWR value of damaged cable

Cable open situation ALC

105

RT group These alarms come from  External fault: Rx power low alarm is generated because of bad propagation or by remote terminal faulty  ODU failure: PSU fail alarm or RF VCO alarm or RF IF alarm is activated

ALC

106

ALC

107

Branch-x IDU-ODU Communication fail This alarm occurs in ODU when on carrier used to receive command from IDU, are detected: 

CRC errors



Loss of frame

This carrier is separated from carrier used for opposite direction (ODUIDU) and from TX or RX carriers

ALC

108

Branch-1 RT Radio Power Supply This alarm is active when the Power Supply section of the radio doesn’t work properly or is in failure condition (voltage in input out of range). Depending voltage value, radio can work. When the under/over voltage is too high, radio is off and other alarms (cable open) cover this.

ALC

109

Branch 1 RT VCO fail

Tx & Rx

This alarm occurs when VCO in RF unit is not able to lock any frequencies. Every problem in VCO causes alarms in both directions: RF unit is not able to convert IF Tx in RF Tx (Tx Power Low alarm) and RF Rx in IF Rx . In this situation the alarm is active together with Tx Power Low and all Rx alarms because RF channel is not locked.

ALC

110

Branch 1 RT If fail This alarm occurs when is not present IF signal inside ODU. There are two different IF signals but one alarm only. No IF Tx : the alarm is on and causes Tx Power Low No IF Rx: the alarm is on with all Rx alarms Rt If fail can be caused by Modulator fail (no IF Tx) When VCO is faulty, RF unit gives a IFRX signal made up of noise: this is enough to mantain IF fail alarm off (but Demodulator cannot work Rx alarms). ALC

111

Branch 1 RT Tx Power Low

Tx

This alarm occurs when Tx power is 3 dB under standard output of ODU-RF unit. ATPC and manual attenuation do not affect this alarm that is due by internal failure of RF unit. This alarm can be activated by a manual operation also: Tx Transmitter off in Radio Branch - Settings If both Rx Power Low and Tx Power Low are active, RF unit inside ODU is faulty

ALC

112

Branch 1 RT Rx Power Low

Rx

This alarm occurs when Rx power is under a defined threshold (about 10 dB under standard Rx level) Threshold value can be set for both branches in range - 40 dBm- 99 dBm in LCT - General preset The alarm Rx Power Low is a branch alarm and it is used to drive Rx switch

ALC

113

UNIT group This group generates alarms when one of the units, the equipment consists of, is faulty or does not respond to controller polling:  Unit fail  Unit is not responding  Unit is missing  Unit hardware mismatch  Unit software mismatch ALC

114

ALC

115

OTHER ALARMS

ALC

116

Performance alarms Every performance measure can drive the relevant alarm if threshold is exceeded. Threshold in sec. relevant 15 minutes alarm Threshold in sec. relevant 24 hours alarm Threshold in dB of Rx alarm alarm counter reset

If 0, alarm is disabled ALC

15 minutes alarms severity 117

Performance monitoring 15 min. alarms 24 hours alarms

PRX < -70

dBm

P

>

5 -5

dB

m

RX

R = 15 minutes

ALC

118

Recorder : Prx

date

ALC

LCT

time

dBm

119

Measures “Performances” is a group of measures, 15 minutes by 15 minutes, day by day, recorded by the equipment itself and downloaded on the PC (the download needs bitrate). These measures remain active also with SCT (and PC) disconnected. “Recorder Prx “ is the recording of Rx power on a log file inside the PC: every time a new value is measured a new “record” is written inside the log file with info of when (day, hour, minutes and seconds) and how much (dBm measured). This recording remains active until SCT is connected to the equipment.

ALC

120

Current Alarms

ALC

121

Switch modes  Auto

Preferential: operator can select which branch must be operative without alarms. Wait Time = time before coming back to the preferential branch when alarms disappear. In this way the controller doesn’t switch continuously in case of fleeting alarms. Reset = Wait Time is not respected Full auto: both branches have same priority  Manual

forcing

Operator can select which branch must be operative despite alarms

ALC

122

Tx switch criteria 1. 2. 3.

4. 5. ALC

RIM PSU alarm Highest priority Manual forcing Cable short/ Cable open alarm Modulator failure ODU unit failure alarm VCO failure alarm IF unit alarm ODU PSU alarm Tx power low alarm Rx failure on both remote radios lowest priority Revertive Tx 123

Rx switch criteria 1. 2. 3.

4. 5. 6. 7. 8.

RIM PSU alarm Highest priority Manual forcing Cable short/open alarm Base band unit failure alarm Demodulator failure ODU unit failure alarm VCO failure alarm IF unit alarm ODU PSU alarm High BER alarm (selectable: BER>10-3,-4,-5) Low BER alarm (selectable: BER >10-6,-7,-8) Early warning alarm (selectable: BER >10-9,-10,-11,-12) RF input low (selectable from -40dBm to -99dBm) CRC pulse Revertive Rx lowest priority ALC

124

EQUIPMENT FEATURE MANAGEMENT ALC

125

LOOP FACILITIES Local Tributary Loop : used to test the cable interfacing



for the equipment upstream Remote Tributary Loop : used to test two direction link



performance making use of an unused 2 Mbit/s signal 

Baseband Loop : it permit to test the LIM circuits



IDU Loop : it permit to test the complete IDU (optional)



RF Loop : it permit to test the complete radio terminal

ALC

126

BASEBAND LOOP

RF LOOP

IDU LOOP

MOD-DEMOD

RF

RIM 1

Branch

Line side

BASEBAND 1 LOOP

ODU 1

AL : available loops

data direction: - towards the equipment that has enabled the loop (baseband, IDU, RF - selectable for E1 loop - only local loops MO DEMO RF RIM1 IDULOP ODU1 RFLOP

MUX -DEMUX

BA

E1LO

D-

OP

SEBAND OPL LA dat

:av

ilabe

directon: onlyca-setbwrdh

lops

lopsfrE1equimnt

thasenb

ledthop(

basend,ID

U,RF)

LIM

MUX-DEMUX

E1 LOOP

LIM

Radio side ALC

LOOPS 127

Line side

ALC loop: external PRBS

Radio side

E1 loop line side : loop works with line enabled or not E1 loop radio side : loop works with line enabled on local side and on remote side Base Band, IDU, RF loop : loop works if line used is enabled local side and on remote side ALC

128

loops: internal PRBS

Alarm OFF: signal is back!

E1 loop line side: it is before PRBS checking point E1 loop radio side: loop works with line enabled on remote side, indifferent* on local side. Base Band, IDU, RF loop: loop works any status of local* and remote line __________________________________________________________ ALC * PRBS enables automatically the local side of used line

129

Propagation Link E.I.R.P = Pt + Gt+ Cable loss Free space loss (L in Km, f in GHz) Received power

PT

A fs = 92.44dB + 20 Log ( L ⋅ f )

PR ( dBm ) = PT ( dBm ) − A fs ( dB ) + GT ( dB ) + GR ( dB )

L

PR

h

ALC

130

Antenna D = antenna diameter λ = wave lenght = c/f

D

η=

Aeff / Ageo= antenna efficiency ≈ 0,6

8 −1 3 ⋅ 10 ms c = speed of light =

 D 2 ⋅π 2  Antenna gain G = 10 Log  ⋅η  2  λ 

ALC

131

1) Refraction Snell law:

α2

n2

n1senα1 = n2 senα 2

α1

n4

n3

n1

n2

n1

k < 4/3 (sub-standard)

k > 4/3 (super-standard)

ALC

k = 4/3 (standard)

132

2) hgeo …earth is not flat 2

hgeo

L = R0

considering geometrical visibility on a planet with no air 2

L ′ = hgeo k ⋅ R0

with k4/3 considering the troposphere refraction (previous page)

hgeo L ALC

R0 = 6378 km

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3) First Fresnel zone A nth fresnel zone gives in phase contributes to radio waves propagation. In order to avoid attenuation is important that first fresnel zone is without obstacle: to tower height calculation, must be add the ray of biggest Fresnel zone, the first zone

λ⋅L RM = 2 L RM ALC

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Height of the towers We have to consider: 

earth’s curvature



k effect (refraction)



first Fresnel zone free

′ } From the first we obtain hgeo , with refraction hgeo becomes hgeo and from the last we have to add also RM

L λ⋅L ′ + RM = = hgeo + k ⋅ R0 2 2

htower ALC

135

example L = 20 km f = 23 GHz k = 4/3

2

L ′ = hgeo = 0.047 km = 47 m 1.333 ⋅ R0

R0= 6378 km

+

λ⋅L RM = = 8.1m 2 htower= 47m + 8.1m = 55.1m ALC

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Fade Margin

…from previous page: 4QAM/16x2 L = 20 km

PT= +20 dBm

f = 23 GHz

HBER - 82 dBm

A fs (dB) = 92.44 + 20 Log ( L ⋅ f ) = 92.44 + 53.26 = 145.7dB x = gain of antennas

FM = 40dB (purpouse)

FM= PR-HBER PR= -82dBm + 40dB = -42dBm

PR ( dBm ) = PT ( dBm ) − A fs ( dB ) + GT ( dB ) + GR ( dB ) GT+GR= 2G = PR-PT+Afs= -42dBm-20dBm+146dB=84dB GT=GR=42dB

ALC

D=60cm G=40dB

D=80cm  G= 42,6dB

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Rain attenuation (f > 8GHz ) freq

\

rain

25 mm/h

100 mm/h



10 GHz 

0.5 dB/km

2.5 dB/km



15 GHz 

1.5 dB/km

7 dB/km



20 GHz 

2.1 dB/km

10 dB/km



30 GHz 

4 dB/km

15 dB/km



40 GHz 

6 dB/km

20 dB/km

ALC

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E

Rain depolarization

H vertical polar. e.m. wave

Drop weight H E horizontal polar. e.m. wave

Wind I

h

v GHz

Drag (air resistence) ALC

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Multipath

Direct ray

A

B

Indirect ray

Indirect ray, depending on its phase, can increase or decrease the power of the main stream Two rays model

[

H (ω ) = α ⋅ 1 − b ⋅ e

− j (ωτ −δ )

]

Direct ray: amplitude = α Indirect ray: amplitude = αb , phase delay = δ , time delay = τ In B position, received signal has a notch every 1/τ Hz with deepness depending on b ALC

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THANK YOU

ALC

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