Microwave Link Design and its all steps

Microwave Transmission
 Microwave Range Microwave range starts from .3Ghz to 300Ghz
 MOST PRACTICAL RANGE FROM 1 GHz TO 100 GHz
 ALCATEL MW RANGE 7-8-13-15-18-23-25-28-38 GHz
ADVANTAGES OF MW
1. 1- COST EFFECTIVE.
2. 2- SINGLE POINT MAINTENANCE.
3. 3- QUICK DEPLOYMENT ACROSS RIVERS AND MOUNTAINS.

TYPES OF LINKS
 TYPES OF THE LINKS ACCORDING TO CAPACITY

PDH PHYLESIOCHRONOUS DIGITAL HIRARCHY
4E1,16E1,64E1
Alcatel PDH(CM-PAK PROJECT).
4E1,8E1,16E1,32E1.

SDH SYHCRONOUS DIGITAL HIRARCHY
STM-1,STM-4,STM16,STM-64.
PRACTICALLY (Pakistan) USED STM-1 & XPIC(2STM-1)

PDH
 AUDIO FREQUENCY =3.4 Khz INTELIGIBILITY NOT DISTURBED
 SAMPLING RATE = 8Khz sample/sec TO AVOID ALISING
 BITS PER SAMPLE = 8 bits/sample ENOUGH QUANTIZATION LEVEL TO DESCRIBE THE SIGNAL
 DATA RATE = (8bits/sample )(8khz samples/sec)= 64kbps
 E0 = 64kbps
 E1 = (32 )(64Kbps) = 2.048 Mbps (32 CHANNELS, FIRST USED FOR SYNCHRONISATION & 16TH
SIGNALING)
 E2 = (4)*E1 = 4 (2.048) = 8.448 Mbps
 E3 = (4)*E2 = 4(8.448) = 34.36 Mbps
 E4 = (4)*E3 = 4( 34.36) = 139.264 Mbps.

SDH
DATA RATE EQUILENT PDH
STM-1 155.52 Mbps 63E1
STM-4 4*155.52 = 622.08 Mbps 252E1
STM-16 4*622.08 = 2.488 Gbps 1008E1
STM-64 4*2.488 = 9.953 Gbps 4032E1

TYPES OF LINKS
 1.2 TYPES OF THE LINKS ACCORDING TO CONFIGURATION
 1+0
 1+1
 1+1 HST (EQUIPMENT PROTECTION)
 1+1 SD (EQUIPMENT + PATH PROTECTION +BEST METHOD TO MINIMIZE MULTIPATH
INTERFERENCE.)
 1+1 FD (CHANNEL PROTECTION)
 TWIN PATH (NODAL SOLUTION)

LINK BUDGET
 IF filter loss
 RF filter loss

MW DISH GAINS
 DISH GAIN DEPENDS UPON FREQUENCY AND SIZE AND DISH TYPE

OUT PUT POWER
 THE KEY IS SYSTEM GAIN

EMISSION DESIGNATAR
 Emission designator

SYSTEM CHARACTERISTICS
4E1

FREQUENCY

SYSTEM CHARACTERISTICS
16E1

FREQUENCY

CAPACITY, MODULATION &
BAND WIDTH
 AS THE CAPACITY INCREASES WE HAVE TO INCREASE BANDWIDTH OR
MODULATION SCHEME,
 ITS DEPENDS UPON OUR CHOICE HOW TO SELECT BEST CHOICE.

MODULATION &
BANDWIDTH
MODULATOR
128QAM
64QAM
16QAM
8PSK
4PSK
2PSK
F0 +10 +20 +30 +40 +50
-10
-20
-30
-40
-50
FREQUENCY (MHz)
100MB/s
supposed that
100Mb/s data is carried by different level
of the modulator

LINK BUDGET
 EIRP ( EFFECTIVE ISOTROPIC RADIATED POWER)
 EIRP IS ACTUAL RF POWER MEASURED AS MEASURED IN THE MAIN LOOB.
 EIRP = 24 dbm – 1.7 dbm + 46.4 dbm = 68.70 dbm
 RECEIVER SENSITIVITY (RX THRESHOLD)
IS THE WEAKEST RF SIGNAL THAT A RADIO NEEDS RECEIVE TO DEMODULATE & DECODE A PACKET OF
DATA WITHOUT ERRORS.
IT DEPENDS UPON BER THRESHOLD , FREQUENCY BAND , MODULATION SCHEME &. CAPACITY. IN THIS
LINK BUDGET IT IS -85dBm.
 THERMAL FADE MARGIN
(SYSTEM OPERATING MARGIN OR FADE MARGIN)
FADE MARGIN= RX SIGNAL – RECEIVER SENSITIVITY
= -28.35 dbm-(-85dbm) = 56.65 dbm.

LINK BUDGET
 FREE SPACE LOSS
The Free Space Loss is predictable and given by the formula.
FSL = 92.4 + 20Log D + 20Log F
FSL = Free Space Loss (dB)
F = Frequency of transmission (GHz)
D = Distance between antennas (km).
FSL = 23.52 +24.30+ 92.4 = 140.29
 RX SIGNAL (dBm)
RX Signal = EIRP - FSL + RX Antenna Gain – Coax Cable Loss
RX Signal = 68.70dBm -140.29 + 46.4 dBi– 1.7dBm = -26.86dbm
BY INCLUDING REGIONAL EFFECTS (PATH DEPENDENT LOSSES)
RSL = -26.86 -1.46 = 28.32 dBm.

LINK BUDGET
 What Is the Minimum SOM(FADE MARGIN) Needed?
 Regarding the minimum SOM needed, there is no absolute answer to this question,
but the higher it is, the better.
 Most agree that 20 dB or more is quite adequate. Some think as low as 14 dB is still
good.
 POLARIZATION
ORIENTATION OF ELECTRIC COMPANENT OF EM WAVE WITH RESPECT TO GROUND
TYPES USED IN MW LINKS HORIZONTAL VERTICAL
CHOICE CRITERIA : VERTICAL POLARIZATION IS PREFFERED BECAUSE IT IS LESS PRONE TO
NOISE & FADING, BUT TO AVOID INTERFERENCE WE ALSO USE HORIZONTAL POLARIZATION.

LED’s FUNCTIONS
 ON GREEN WHEN POWERED ON
 ODUW ( OUT DOOR UNIT WORKING)
GREEN WHEN CARRYING TRAFFIC
 RDI (REMOTE DEFECT INDICATION)
RED WHEN THERE IS ANY MINOR OR MAJOR ALARM ON FAR END
 LDI (LOCAL DEFECT INDICATION)
RED WHEN THERE IS ANY MINOR OR MAJOR ALARM ON NEAR END
 MIN (MINOR) RED MINOR ALARMS
 MAJ (MAJOR) RED MAJOR ALARMS

LED’s FUNCTIONS
 EOW (ENGINEERING ORDER WIRE)
EOW IS COMMUNICATION PATH FOR VOICE OR DATA
THIS IS TRI STSTE LED
1- GREEN ENGINEERING ORDER WIRE FREE.
2- YELLOW ENGINEERING ORDER WIRE BUSY.
3- YELLOW BLINKING RECEVING A CALL
 ATTD (ATTENDED)
YELLOW IT IS ON WHEN ACKNOWLEDGEMENT BUTTON HAS BEEN
PUSHED

IDU
 ACKNOWLEDGEMENT (PUSH BUTTON)
THIS PUSH BUTTON IS USED FOR CALL .IT TURNS OFF LEDs MAJ/MIN
AND TURN ON YELLOW LED.
 LAMP TEST (PUSH BUTTON)
IT IS USED TO VERIFY THAT LEDS ARE WORKING PROPERLY OR NOT.
 RESET (PUSH BUTTON)
IT IS USED FOR THE RESET .

IDU
 TPH ( TELEPHONE PORT RJ-11)
EOW TELEPHONE RJ11 PORT.
 OS (OPERATING SYSTEM)10/100 base-T RJ-45 PORT
ETHERNET CRAFT TERMIAL ACCESS.
TWO LEDs ON IT
1- GREEN ETHERNET LINK IS UP 2- ORANGE BLINKING TX OR RX ACTIVITY
 IND (DEBUG) FOR FACTORY USE ONLY
OS & IND BOTH ARE 10/100 base-T INTERFACE(100MBPS OR 10MBPS OVER TWISTED PAIR
CABLE
 ECT (EQUIPMENT CRAFT TEMINAL) RS-232 INTERFACE
9 PIN D TYPE FEMALE CONNECTOR

IDU
 8E1/DS1 ( 37 PIN D-SUB FEMALE CONNECTOR)
1-8E1/DS1 TRIBUTRIES ACCESS.
 ESC (ENGINEERING SERVICE CHANNEL) 15 PIN FEMALE CONNECTOR
 ALM (ALARM HOUSEKEEPING)
 NMS-G703
USED TO ACCESS NE WITH ADJACENT NE.
 NMS-V11
USED TO ACCESS NE WITH ADJACENT NE.
 SCSI (SMALL COMPUTER SERIAL INTERFACE) 1+1 INTERCONNECTION

IDU
 POWER OPTIONS (3 PIN CONNECTOR)
THERE ARE THREE OPTIONS
1- 48 TO 60 VDC 20% (9.6)
2- 24 VDC 20% (4.8)
3- 48 TO 60 VDC 20% (9.6)
WHY WE USE NEGATIVE VOLTAGE ( e.g. -48VDC) ?
TO MINIMIZE THE INTERNAL NOISE
IN – VOLTAGE THE ELECTRON FLOW IS EQUIPMENT TO GROUND SO NOISE POSSIBILITY IS LESS
IN + VOLTAGE THE ELECTRON FLOW IS FROM GROUND TO EQUIPMENT SO NOISE POSSIBILITY IS HIGH

COMMISSIONING
 STARTING THE CRAFT TERMINAL
SUPERVISION ---------> START

COMMISSIONING
 SHOW EQUIPMENT

COMMISSIONING
 USER NAME = initial
 Password = initialing

POWER CONTROL
METHODS
 RTPC (RTPC STANDS FOR RADIO TRANSMITTING POWER CONTROL

ATPC (AUTOMATIC TRANSMITTING POWER CONTROL)
IN THIS CONFIGURATION WE SELECT THRESHOLD FOR THE POWER CONTROL
ATPC MIN POWER 4 dbm
ATPC MAX POWER 24dbm
RX THRESHOLD LEVEL -50 to-100 dbm
ATPC MAX VALUE DEPENDS UPON ACHIEVED RSL AND RX THRESHOLD LEVEL
 MTPC (MANUAL TRANSMITTING POWER CONTROL)
IN THIS POWER CONTROL METHOD THE TRANSMITTING POWER IS SET BY
DEFAULT TO MAXIMUM VALUE,IF WE WANT TO REDUCE TX POWER WE HAVE TO
INTRODUCE ATTENEUATION IN IT.

IF FREQUENCY
 IF FREQUENCY (INTERMEDIATE FREQUENCE)
BAND SPECIFIC ( AM,FM, VESTEGIAL ,MW etc) &
EQUIPMENT SPECFIC (Alcatel, NEC, HARRIS etc)
 TWO MAJOR CLASSES
IF TX FREQUENCY = 340 Mhz
IF RX FREQUENCY = 140 Mhz
&
IF TX FREQUENCY = 850 Mhz
IF RX FREQUENCY = 450 Mhz

IF CABLE CHARACTERISTICS
 IF TX FREQUENCY = 340 Mhz
 IF RX FREQUENCY = 140 Mhz
 CABLE IMPEDENCE = 50 Ohm
 MAXIMUM LENGTH = 300m
 TNC CONNCETORS ARE USED AT EACH END.

MW DISH PARTS
 REFLECTOR
CONVERGE THE INCOMMING WAVES TO FEED HORN & DIVERGE THE OUTGOING
WAVES TO REFLECTOR .
 FEEDHORN
THIS IS FEED MECHANISM.
 SHROUDER
ALLIGN THE MISS ALIGN WAVES TO MINIMISE DIFFEREACTION & REFLECTION TO
MINIMIZE THE INTEFERENCE.
 RADOME
TO PROTECT THE REFLECTOR & FEED HORN AGAINST DUST, WATER etc.
 ASSEMBLY
TO ATTACHE THE DISH WITH POLE.

HOW TO UPGRAD FLASH
CARD
 Check the flash card version.
 if the flash card is of version 2.0.2 or 2.0.3 then up gradation is required.
 CD of the required version.
 Insert the CD & make the path.
 After up gradation activate the upgraded version.

Abnormal Condition List
This option enables you to check if there is any loopback or TX Mute activation.

TX MUTE
This option helps you to avoid interference during Alignment of new link in the congested
environment.
Also used during alignment of SD links and XPIC links.

EVENT LOG
Event log is very useful for the links which flactuates during night hours,at that time
you are not on the site and you want to know the reason of fluctuations .

RF LOOP BACK
 BY RF LOOP BACK YOU CAN CHECK YOUR HARDWARE (IDU,ODU,IF CABLE,CONNECTORS),THAT
THEY ARE WORKING PROPERLY

TRIBUTRY LOOP BACK
 BY TRIBUTRY LOOP BACK WE CAN PERFORM BIT ERROR RATE TEST .

SAVE CURRENT
CONFIGURATION
 MIB MANAGEMENT MIB INCLUDES ALL THE SYSTEM INFORMATION EXCEPT ROUTING
CONFIGURATION DATA,BECAUSE IT IS CONSIDERED TO BE UNIQUE FOR EACH LINK.

BACK UP 17
 BY using this option we can save NE configuration on CT( craft terminal)
 Write the suitable filename then click on confirm Backup to make the Back up on
CT.

RESTORE & ACTIVATE
 SELECT ONE OF THE BACK UP PRESS Confirm Restore
 By pressing the Reset previous configuration will be cancelled & new is applied.
 To activate new configuration click MIB Click activate

RESET BY SOFTWARE
YOU CAN RESET NE FROM THIS OPTION.

BIT ERROR RATE
THRESHOLD
 BER = ERRORS/TOTAL NUMBER OF BITS
 EB (Error Block) A block in which one or more bits are in error.
 ES (Error Second) A second during which an error block (EB) occurs.
 SES (Severely Error Second) Any second which contains more than 30%
error Blocks.
 BBE (Background block error) An error block which is not part of SES.
 UAS (Unavailable seconds) Unavailable time begins after 10 consecutive SES.

EQUIPMENT ALARM
 Alarm Replaceable Unit Problem
Problem on a replaceable Unit Replace the Unit
 Alarm Replaceable Unit Type Mismatch
Mismatch between the installed unit and its software configuration
change the software according to unit specs or change the unit.
 Alarm Internal communication problem
connection b/w odu & idu is lost
 Alarm Version Mismatch
Mismatch between the CT software version and the equipment software version.
Download the new software version.



Microwave Link Design and its all steps

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