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