Satellite Communication in ONGC

This is to certify that Mr. Srijan Kumar has completed the Summer training on “Satellite Communication in

ONGC” during 1st July 2011 to 30th July 2011 at ONGC Vasundra Bhavan,Bandra(East) under the guidance of

Mr. Vikas Shinde, Chief Engineer(E &T).

Vikas Shinde C.E.(E&T) C.E(E&T)

Mumbai high asset is biggest oil & gas field in western offshore.The field is located about 165 kilometers away in Arabian sea at a water depth in 70 to 80 meters.

The field was discovered in 1974 by the legendry rig sagar samart.The field producing about 2,60,000 barrels of oil per day.

The backbone of the offshore facility comprises of 5 process complexes MNW,NQP,BHS,SHP,ICP,24 process platform and 107 unmanned well platforms 665 oil wel

In the ONGC platter there are 665 oil wells.34 free gas wells and 183 water injection wells besides a pipeline network of approx. 4000kms.

ONGC has its own telecommunication network which connects its HQ at Dehradun to all regional offices located all over india,Offshore Rigs and Process Platforms.This network is known as ICNET.

There are various methods in wich we can gain in formation from one part of the place to other through satellite communication it includes voice and data communication.

Oil and natural gas coorporation has approached the department of telecom for allocation on spectrum to setup a captive communication network for its Western Offshore site.

The oil PSU has sought permission to build a captive communication network based on Broadband Wireless Access System for the Western Offshore location in the 3.3 GHz frequency band.

Earlier, such request of ONGC has been considered for BWA system in the 3.3 Ghz band for on shore locations in Gujarat.

1) EPABX (for voice) 2) MUX3) MODEM (Modulator & De-modulator)4) ROUTERs5) UP-CONVERTER6) DOWN-CONVERTER7) SSPA (solid state power amplifier)8) LNA (low noise amplifier)9) ANTENNA

Telephone Line

AnalogExchange

AnalogSpeech

A/D D/A

Telephone 1 Telephone 2

Telephone Line

Telephone Line

DigitalExchange

Analog

Telephone Line

AnalogSpeech

Analog

A private branch exchange is a telephone exchange that serves a particular office or a business.

This is the opposite of one that a common carrier or telephone company operates for many businesses or for a general public.

The EPABX in the above used system is only for the transmission and the reception of the voice signals via satellite. The EPABX makes connection among the internal telephones of a private organization and also connect them to the general public using ISDN, MTNL lines.

ISDN is a set of communication standards for simultaneous digital transmission of voice, video data and other network services over the traditional circuits.

ISDN are of two rates :-1) Basic Rate Reference 2) Primary Rate Reference

Integrated Services Digital Network (ISDN)

Integrated Services Digital Network (BRI)

The entry level interface to ISDN is the basic rate interface. A 128 Kbit/s delivered over a pair of standard telephone copper wire.

The 144 Kbit/s payload rate is broken into two 64 Kbit/s and one 16 Kbit/s signaling channel. This is sometimes referred to as 2B+D.Here B refers to 64 Kbit/s and D refers to 16 Kbit/s.

B refers to the ISDN channel in which the B channel(bearer) is a telecommunications term which the primary data or voice communication is carried.It has a bit rate of 64 kbit/s in full duplex.

D channel(data) is a telecommunication terms which refers to the ISDN channel in which the control of signalling information is carried.

The bit rate of the D channel of a basic rate interface in 16 kbit/s and in primary rate interface it is 64 kbit/s.

ASDL is a form of DSL,a data communication technology that enables faster data transmission over copper telephone lines than a voiceband modem can provide.

ASDL is generally offered at downstream data rated from 512 Kbp.As to about 6 Mbps.ADSL was specifically designed to exploit the one-way nature of most multimedia communication in which large amounts of interactive control information is returned.

A MUX or a multiplexer combines the many voice & Data signals into a single path and gives the output to the modem. It is used only for both the voice & data signals.

The MUX used is Alcatel Make & Model is Mainstreet 3600/3600+ .There are various cards having different functionalities and installed in the MUX.

1) V.35 PRI card2) V.35 card3) LGS card4) LGE card5) E&M card6) DSP card7) DSP 5 card8) Control card

A modem is a device that modulates an analog carrier signal to encode digital information and also demodulates such a carrier signal is to decode the transmitted information.

It is a microprocessor controlled BPSK,QPSK or OQPSK for use as part of transmitting or receiving equipment in a communication system. The modem is designed for service in an SCPC (Single Channel Per Carrier) system where two modems are set for operation.

The radio frequency up-converter is a device that takes an input of intermediate frequency of a specific frequency range and outputs it on a higher frequency. The up-converters are designed for use in the communication system on satellite uplink data systems for the transmission of SCPC,DAMA and TDMA communication signals. The RF output frequency range for the up- converters used in the above is as follows. UT-4505 5845-6425 MHz

A radio frequency down-converter is a device that takes an input of higher frequency energy of a specific frequency range and outputs it on a intermediate frequency.

The down-converters are designed for use in the communication system on satellite uplink data systems for the transmission of SCPC,DAMA and TDMA communication signals.

The RF output frequency range for the up-converters used in the above is as follows.

DT-4503 5845-6425 MHz

A router is a networking device whose software and hardware are usually tailored to the tasks of routing and forwarding information.

The router in the communication system above is used for the data to be transmitted from one end to the other.

Router consists of two major aspects of internet which is useful for the users they are lan and wan.

LAN is Local Area Network and WAN is wide area network.LAN and WAN were the original categories of area networks.while the others have gradually emerged over many years of evolution.

A LAN connects to network devices over a relatively short distance. In TCP/IP networking, a LAN is often but not always implemented as a single IP subnet.

A WAN is a dispered collection of LANs.A network device called a router connects LANs to a WAN.

SSPA in a HPAC series offer premium performance and reliability for satellite uplink calculations. These C band high power amplifiers provides linearity and gain stability.

Features of SSPA :-1) Frequency range: 5.85 to 6.425 GHZ2) Output Power @ 1db Gain compression is

50.6 dbm.3) Temperature compensation4) 20 DB gain adjustment5)1:1 Redundant system

The low noise amplifier is a special type of electronic amplifier or amplifier used in comm. Systems to amplify very weak signals captured by the antenna.

LNA is very close to the antenna. It is a key component, which is placed at the front-end of the radio receiver circuit.

So it is necessary for an LNA to boost the desired signal power while adding as little noise and distortion as possible so that the retrieval of this signal is possible in the later stages in the system.

The 6.3 meter earth station antenna meets international specifications & is installed at ONGC. The reflector consists of 40 dual shaped panels placed in 3 rows over 16 trusses emanating from the central hub.

The antenna features shaped cassegrain paraboloid configuration with a conical corrugated horn, sub-reflector. The centre hub is spacious to accommodate receive electronic equipments.

1) Physical Antenna Size: 6.3 meters Antenna Type: Shaped Parabolic Cassegrain Feed: Composite, Shaped cassegrain,2/4 port Linear/Circular2) Electrical Operational: Rx(mhz) Tx(mhz) Frequency: (3625-4200) (5850-

6425) (4500-4800) (6725-7025) Antenna Gain: (C band=46) (C

band=49.3)

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COMSAT SYSTEMS PVT LTD

EPABX

VOICE CODEC

DAMA CHASSIS

VF-Voice Frequency

ROUTER SATELLITE MODEMDIGITAL DATA

COMMUNICATIONSATELLITE

MODEM

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UP CONVERTER

SSPA #1

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& Signalling

Schematic Diagram:

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BHN

ICP

BHS

SCA

SHP

INSAT-3ELOCATION-55º ETRANSPONDER-15

BPB

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HRA

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1) ONGC reference book2) Website: www.isro.org3) Website: mumbai.mtnl.net.in4) Webopedia

THANKING YOU

SRIJAN KUMAREEE branch

REVA INSTITUTE OF TECHNOLOGYBANGALORE