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DSNG SYSTEM
DIGITAL SATTELLITE NEWS GATHERING SYSTEM
WHAT IS DSNG?
• Satellite news gathering (SNG) is the use of mobile communications equipment for the purpose of worldwide news-casting. Mobile units are usually vans equipped with advanced, two-way audio and video transmitters and receivers, using dish dish antennasantennas that can be aimed at geostationary geostationary satellites.satellites.
Cont….
• A modern DSNG van is a sophisticated affair, capable of deployment practically anywhere in the civilized world. Signals are beamed between a geostationary satellite and the van, and between the satellite and a control room run by a broadcast station or network.
TYPES OF DSNG IN AIR NETWORK
• MOBILE DSNG SYSTEM Equipments are mounted
within a vehicle.
• FLYAWAY DSNG SYSTEM Equipments are mounted within carry away suitcases.
LNBC
(1+1)
Audio
(Stereo)
from OB spot
DIGITAL RECEIVER
DIGITALENCODER
(1+1)
LEFTDIGITAL
MODULATOR
(1+1)RIGHT
UPCON-VERTER (1+1)
SSPA
100 W
(1+1)
1.2 M Dish
Antenna
LEFT
RIGHT
Analog
Audio
(Stereo)
LNBC
(1+1)
DIGITAL RECEIVER
LEFT
RIGHT
Analog
Audio
(Stereo)
UPLINKING SET UP RECEIVE/ HUB STATION
Power
Divider
TYPICAL MOBILE DSNG SYSTEM LOOKS LIKE
Lay out of Mobile DSNG System
TYPICAL FLYAWAY DSNG SYSTEM LOOKS LIKE
Lay out of Fly Away DSNG System
COMPONENTS OF DSNG SYSTEM• MOBILE DSNG OUTDOOR UNIT : EASILY DEPLOYABLE
1.2M ANTENNA UNIT MOUNTED ON TOP OF THE VEHICLE ALONG WITH ACCESSORIES LIKE LNBC
Cont…
• INDOOR UNITS : i. BASEBAND UNITS LIKE ENCODER,MODULATOR.ii. UPCOVERTERS,SSPAiii. UPS, PETROL GENERATOR.
DESIGN CONSIDERATION
• Weight consideration.• Link Budget calculation.
1. LINK BUDGET CALCULATIONS
1. Antenna Gain : G = Gain of Antenna
D = Diameter of Antenna 𝝀 = Wave length 𝜼 = Efficiency (usually 0.5 to 0.65)
The gain if the antenna under consideration = 37 dBi.
LINK BUDGET CALCULATIONSCont….
2. Transmit Station EIRP: 10 Log (Pt x Gt)
Pt = Out put Power of SSPA/HPA in Watts. (Say : 10Watts = 10 dBw)
Gt = Gain of Antenna ( 37 dBi)
EIRP = 10 dBw + 37 dB = 47 dBw
LINK BUDGET CALCULATIONSCont….
3. Flux density at Satellite Antenna Input := EIRP -162.2 (47 - 162.2 = 115.2 dBw/M2)
4. Path Loss : Lp = Path Lossd = Distance between uplink site & Satellite
(approx 36,000,000 meters) 𝝀 = Wave length
In our case it is about 200 dB at 6 GHz
LINK BUDGET CALCULATIONSCont….
5. C/No (uplink) = EIRP + G/T(sat) + Lp – k= 47 + (-2) + (-200) – (- 228.6)= 73.6 dB-Hz
6. EIRP(downlink) = Sat. flux density(operating)
+ (Sat. EIRP Saturated – O/P Back-off)+ (S.F.D. - I/P Back-off)
= -115.2 + (38 – 4) - (- 85 – 6.5)
= 10.3 dBw
LINK BUDGET CALCULATIONSCont….
7. Down Link Path Loss :
(In our case it is about 196 dB at 4 GHz)8. Receive G/T (6 m antenna) = 25.5 dB/°K9. C/No (downlink) = EIRP + G/T(CES) + Lp – k
= 10.3 + 25.5 – 196 + 228.6= 68.4 dB-Hz
10.Eb/No. = C/No – 10 Log (Data Rate) [256kbps]= 68.4 – 54.1 = 14.3 dB.
120 WC - BAND
120 WC - BAND
UCU 60 C BAND
UCU 60 C BAND
MODEM DMD 20 RADYNE
MODEM DMD 20 RADYNE
ENCODER DAC 700 COMSTREAM
ENCODER DAC 700 COMSTREAM
DUMMY LOAD
LNA
MODEM, UPCONVERTOR & SSPA CHANGE OVER SWITCH
7812 7812
LNBC
LNBC
SPLITERSPLITER
ABR 202A
ABR 202A
ANTENNA CONTROLER GIGASAT STC 100
OFFSET ANTENNA DAUL FEED 1.2 mts. GIGASAT
UP CONVERTOR C-BAND GIGASAT SOLID STATE POWER AMP.
CODAN
MODEM SWITCH.
SPLITER SPLITERUP CONVERTOR SWITCH.
RF SWITCH
WA
VE
GU
IDE
CO
-AX
IAL
CA
BLE
DAUL LNBC UNIT
WA
VE
GU
IDE
WAVE GUIDE
CO
-AX
IAL
CA
BLE
CO
-AX
IAL
CA
BLE
- 22 dBm
CO
-AX
IAL
CA
BLE
CO-AXIAL CABLE
CO-AXIAL CABLE
LNBC SWITCH
- 15 dBm
CO-AXIAL CABLE
CO
-AX
IAL
CA
BLE
CO
-AX
IAL
CA
BLE
ISO MPEG I L-II
DATA CABLE
L
RIG
HT
LEF
T
R
SPECTRUM ANALYZER
ALA
RM
CA
BLE
ALA
RM
CA
BLE
ALA
RM
CA
BLE
ALA
RM
CA
BLE
ALA
RM
CA
BLE
ALA
RM
CA
BLE
+12 V CABLE +12 V CABLE
CO-AXIAL CABLE
CO-AXIAL CABLE
CO-AXIAL CABLE
CO-AXIAL CABLE
SP
LIT
ER
1:4
LEFT
RIGHT
LEFT
RIGHTAN
ALO
G A
UD
IO
AB
R #
2
A
BR
#1
BLOCK DAIGRAM DSNG
RF SWITCH CHANGE OVER SIGNAL
MOXA MOXA
LAB TOP
USB CABLE 2 USB CABLE 1
CO
M 1
3
CO
M 1
2
CO
M 1
1 C
OM
10
CO
M 9
CO
M 8
CO
M 7
C
OM
6
MAINTENANCE & COMMAND SETUP
PAD
PAD
R L
AES/EBU
AES/EBU
WA
VE
G
UID
E
ANTENNA PSU
DA-20 MOTORIZEDFLYAWAY ANTENNA PSU WITH EMERGENCY STOP GIGASAT
5. 8 - 6
.65 GHz
3.4
- 4.
2 G
Hz
( -
80 d
Bm
)
I/P AC 100-240V O/P AC 100-240V 15V DC O/P
LNBC REDUNDANCY CONTRLLER DC MONITOR
PCB LNA PSU
70 M
Hz
70 ±
18
MH
z
6.0
GH
z
40 dBm
- 40 dBm
SUBSYTEMS OF DSNG
DSNG ANTENNA: Gigasat makeFeatures:– Carbon Fiber make antenna . Weight is less than 90Kg– High efficiency offset feed design providing maximum
gain – 37dBi– Antenna can be stowed.– STC-100 antenna controller enables antenna to acquire
and track satellites.– Manual and motorized operation of all the three antenna
motors.
SUBSYTEMS OF DSNGCont…
Antenna Controller:• STC 100 is a comprehensive controller available in 1RU providing
all facilities including – Stow/Deploy– Jog Control– Auto positioning– GPS Receiver– Flux Gate Compass– Store/Recall Memory.
• Communication between STC-100 and Antenna is through an RS485 cross-site connection to the Local Antenna Control unit situated in the antenna cowl.
Antenna Controller Interface diagram:
SUBSYTEMS OF DSNGCont…
120W SSPA. CODAN Make Features:
– 120Watts SSPA– 5.85Mhz to 6.425Mhz frequency range– Third order intermodulation Products is better than
-25 dbc for 3dB Back-off.– 1+1 hot standby configuration.– 65dB gain – Innovative RF Power Combining technology, the latest GaAs
FET devices & Surface – mounted technology are used in this SSPA
SUBSYTEMS OF DSNGCont…
C-Band Upconverter : Gigasat Make Features:
• IF to C-Band Upconverter• Output power : +9dBm (max.)• Gain adjustments : >40dB in 0.5dBsteps• Two stage Upconversion i) from 70MHZ to L-Band
ii) from L-Band to C-Band
• RF flatness across the band ±1dB max
SUBSYTEMS OF DSNGCont…
IF Modulator: Radyne Comstream Make DMD20L
• Modem provides the operation of different parameters such as variable data rates, FEC code rate, modulation type, IF frequencies, interface type can be readily set & changed at the front panel.
• This allow the remote control from computer using RS232.• This modem contains a selectable RS232 or RS485 asynchronous
Com Port for Earth Station – to – Earth Station communications. The baud rate & protocol can be selected from the front panel.
SUBSYTEMS OF DSNGCont…
IF Modulator: Radyne Comstream Make DMD20LFeatures:– IF Frequency Range 52MHZ to 88MHZ– Transmit Power: -5dBm to -25dBm– Supports Data Rates: 64kbps to 256 kbps– Supports QPSK and BPSK – FEC – Viterbi ½ – Supports monitoring and Controlling
SUBSYTEMS OF DSNGCont…Encoder: Radyne Comstream DAC700
Features:• Digital Audio Codec• ISO MPEG I Layer-II Compression• Supports Data Rates: 64kbps to 256 kbps• Accepts Analog and Digital AES/EBU input• Supports monitoring and Controlling
SUBSYTEMS OF DSNGCont…
Digital Satellite Receiver
Radyne Comstream ABR202A
SUBSYTEMS OF DSNGCont…
REDUNDANCY CONTROLLER UNIT, RFS - 60• RFS – 60, Make GIGASAT is used to control 3 switches: One switch
for encoders / modulators, one switch for the up converters and one wave guide switch for the amplifier.
• The front of the controller has LEDs that display the status of each pair of equipment.
• In normal use the switches are set in automatic position.• For any failure the unit will automatically switch away from the
faulty peace of equipment. • If both chains of equipment are normal either chain can be
selected.
SUBSYTEMS OF DSNGCont…
• 5KVA Petrol generator
SUBSYTEMS OF DSNGCont…
Hydraulic Jack System
THANK YOUTHANK YOU