121230136 satellite communication

7/27/2019 121230136 Satellite Communication

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Satellite Communication


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Satellite Communications Sat.Comm Satellite

Receive

Antenna

Trans Antenna

lUplink Fu

Downlink Fd

Earth Station Earth Station


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Satellite Communications

Band Up-LINK(GHz)

Down-Link(GHz)

C- Band

Ku-Band

Ka- Band

5.925 - 6.425

14.00 - 14.50

27.00 - 30.00

3.7 - 4.2

10.70 - 11.70

18.10 20.20


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Satellite Communications

Carrier Frequency : 2.225 Ghz

Frequency Band in Each

Direction: 500 Mhz

No.of Sub-Bands: 12

B/W per Sub-Bands : 36Mhz

Guard Band : 4 MHz

Each Sub-Band : 1RF

BEACON Signal : 4.031 to 4.038 GHz

Sat.Delay : 280 m.sec (one path)


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Equipment in Comm.sat

1) Payload :

Transponder : Transmit, Receive antennas

other equipmentsReceives signals, multiplex, demuliplex, amplify

and transmit.

2)Support Subsystems : Power Supply,Altitude, orbit control eqpt.

Telemetry, Telecommand systems


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Orbits and Systems.

Orbit is Path traversed by a satellite

Satellite


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Orbits and Systems

LEO: Low Earth Orbit:

-- 0-2000 Kms

-- Orbit Period : 90 min

-- Short Round Trip Time (RTT)

-- Used for MSS: Mobile Sat. Series-- Life :5-7 Years


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Orbits and Systems

MEO: Medium Earth Orbit

-- 2000-36000 Kms

-- Intermediate Circular Orbit

-- Use Low Power and Smaller antennathan GEO

--


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Orbits and Systems

GEO : Geo-Stationary Orbit

-- Above 36000 Kms

-- The Orbit Path is called as Clarke Belt

-- Latitude : Zero

-- Altitude : Constant-- Covers 40% of Planet

-- Life :10-15 Years


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GEO Satellite

Rotate at same speed of earth

Rotation Time: 23 Hrs,56 Min,4 Sec

Called as Sidereal Day

Use for Telecom applications

Rotate in Equatorial Plane Rotate Easterly..


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Earth Station

Primary Earth Station:

Diameter of Antenna: 7.5 Mtr

G/T Ratio: 25.7 db/k

Remote Earth Station:

Diameter of Antenna: 4.5 Mtr Mounting : X-Y Type

G/T Ratio :19.7 db/k


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Antenna and Mounting

Different types of Antenna Mountings

1) Azimuth Mounting

Primary (Azimuth) Axis:Vertical to Ground Secondary (Elevation) Axis: Horizontal

2) X-Y Mounting

Primary (Azimuth) Axis: Horizontal toGround

Secondary (Elevation) Axis: Vertical


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Antenna and Mounting

3) Polar Type : Ha Axis: Parallal To Gnd

Dec Axis: Vertical To Gnd

4) Tripod (for Small E/S):

Three Legs, One leg is fixed and other twolegs are Variable


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E/S Configuration

Antenns Subsystems

Low Noise Amplifiers

Ground Communications and Multiplex

Equipments

Station Control Facilities


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INSAT

Indian National Sat.System

For Long Distance Comm.

Metrological Earth Observations

Nation Wide Sat.TV Broad Casting

Nation Wide Radio N/wAnd Many More..


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INSAT (Telecomm)

Long Distance Trunk Routes

Mobile Sat.Service :MSS

Remote Area Business Msg. N/w: RABMN High Speed VSAT n/w : HVNET

Long Distance Telephone Service: LDST

Remote and Rural area Communication

VSAT,IDR,DSPT


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INSAT Series

INSAT -1 Series

- INSAT 1A

- INSAT 1B- INSAT 1C

- INSAT 1D

2) INSAT -2 Series : 5 Sat3)INSAT -3 Series : 5 Sat

4) INSAT -4 Series : 5 Sat only for comm.


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VSAT

VSAT : Very small aperture Terminal

Ku Band VAST offers value added

satellite based services like

Internet,LAN,Voice,fax

Use for Geographically DispersedLocations,Where no other servicesavailable

Poweful Private comm.solutions


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VSAT

Uplink Frq: 14.437 Ghz

Down-Link: 11.637 Ghz

Dish Diameter :1.2-1.8 Mtr

Act Like Small Earth Station

TDMA,DAMA,SCPC/MCPC Star or Mesh Topology

HUB earth Station at Banglore


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DSPT

Digital Satellite Phone Terminal

DSPT using VSAT Network provides

PSTN connectivity to ruralarea,remote,inaccessible area and hillyarea via INSAT

Hub Station at Sikandarabad (A.P) Mostly for North, North East,and East

Region


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DSPT

Up-Link: 13.75- 14.5 Ghz

Down-Link: 10.7- 12.75 Ghz


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IDR

IDR: Intermediate Data Rate sat service

It gives Digital Sat. connectivity to

different exchanges.

C-Band IDR : 2 Mbps,8Mbps connetivity

Ku- Band IDR : To connect TAX

exchanges using SAT. on INSAT-2C

Small Antenna

No interference with M/W


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IDR

Data Service Voice and Non-Voice Circuits Not Beyond 140 Mbps On ISDN or PSTN:--- 64 kbps to 44.736 MbpsModulation: QPSK

Antenna(Remote) : 4.5 Mtr for 2Mbps7.0 Mtr for 8 MbpsAntenna (HUB) : 11/7 Mtr


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HVNET,RABMN

HVNET: High speed VSAT

Data Rate Upto 128 Kbps..

NOC at Mumbai

Thaicom-3 sat.

VSAT antenna dia: 2.4 Mtr


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RABMN

Remote Area Business Msg N/W

Packet switch data nw using spread

spectrum tech. For Remote Area

INSAT-2B

Does not support Voice facility HUB at Sikandarbad..

Antenna dia: 1.2 to 1.8 Mtr

121230136 satellite communication

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