Sunday, 12 March 2017

Guide for Satellite TV and Satellites Used For Indian DTH Services With Capacity

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A handy guide for the satellite TV services, satellites used to broadcast signals for DTH in India. Satellite television is a delivery system for television programs signals from communications satellites orbiting the Earth in 35,786 km above the equator in which geostationary orbits. The signals will be received by an external satellite dish, usually called a parabolic antenna and a low-noise block converter (LNB). Satellite receiver then decodes the TV program to watch on television.

A receiver can use external decoder or a built-in TV tuner. India DD Free Dish sends unencrypted signals that can be decoded by generic decoders, while commercial operators such as Tata Sky, Videocon DTH, Dish TV, and so on use encrypted signals that are decrypted by the chip of the smart card.


Guide for Satellite TV and Satellites Used For Indian DTH Services With Capacity


The satellite TV signals are transmitted in two types of bands:


C-band TV signal - This band is used by analog or digital signals in the range of approximately 4-8 GHz to receive television (TVRO) and requires a larger satellite dish (6 to 8 feet) to pick up the signals and this frequency is not affected by bad weather conditions Such as rain.

Ku Band TV signals - This band consists of digital signals in the frequency range from 12 to 18 GHz used for direct transmission (DTH) and requires a much smaller satellite dish (2-4 feet) to receive most signals, but likely to interruptions in bad weather Such as heavy rain.


Compression standards used to distribute DTH signals are of two types:


1. MPEG 2 format. This is the oldest signal compression standard used by traditional operators such as Dish TV DTH and DD free dish, where each transponder can carry 20 SD Television channels.

2. MPEG 4 format. This is the new signal compression standard introduced in 1999 and is used in India by new DTH operators such as Airtel Digital Dth, Videocon D2H, Reliance Digital TV, Sun DTH and now since October 2015 also Tata sky Dth migrated from MPEG 2  to MPEG 4, with this MPEG compression standard, each transponder can carry about 40 SD channels (less if in HD standard).

Currently, there are six private DTH operators and 1 government direct to home TV service provider in India. The Department of Space (DTH) allows DTH operators to use only satellites ordered by the Indian Space Agency and research (ISRO), and the ability of ISRO satellites is insufficient so they can leverage the use of ISRO capacity from foreign satellites. ISRO is planning three more GSAT satellite to launch to orbit to enhance the capacity for communication and broadband satellite related services. The main purpose of these satellites is to replace transponders from foreign satellite operators.


Satellites used by Indian DTH operators:


INSAT 4A:

This is a satellite, owned by ISRO and launched on December 22, 2005, with a lifetime of 12 years. The geostationary position is 83° East longitude. The satellite has 12 Ku-band transponders, all transmitted by Tata Sky DTH for SD and HD TV channels in MPEG4 compression. The transponders have begun to work with reduced power as the satellite approaches to the end of mission life.

GSAT 10:

This is a satellite owned by ISRO, which was launched on September 29, 2012, with a lifespan of 15 years. Its geostationary position 83° East, where it is connected with INSAT 4A. The satellite has 12 Ku-band transponders. Tata Sky now uses all GSAT 10 transponders in addition to the existing INSAT 4A to increase its transponder capacity and has already started from this satellite with MPEG4 compression to new channels.

ST 2:

This is a satellite launched by a joint venture owned by SingTel and Chunghwa Telecom, on May 20, 2011, with a lifespan of 15 years. The geostationary position is 88° East longitude. The satellite has 41 Ku-band transponders, 12 of which are leased by ISRO for Indian DTH operators. Videocon D2H uses these 12 transponders to transmit its SD and HD channels with MPEG4 compression.

MEASAT 3:

This is a satellite launched by Malaysia East Asian satellite systems with a lifespan of 15 years on December 11, 2006. The geostationary position 91.5° East longitude. The satellite has 24 Ku-band transponders, 13 of which are leased by ISRO for Indian DTH operators. Reliance uses 9 Ku-band transponders for its SD and HD channels using MPEG4 compression, Sun Direct uses 4 Ku-band transponders for transmission only SD channels with MPEG4 compression and also shares 5 Transponder to Reliance Dth for their Encrypted Channels.

GSAT 15:

This is a satellite that was launched by ISRO on 10th of November 2015 with a lifespan of 12 years. The geostationary position 93.5° East longitude. The satellite has 24 Ku-band transponders, 5 of which are used by the DD free dish. In addition, Sun Dth also uses a transponder to transmit HD channels with HEVC compression.

NSS 6:

This is a satellite launched by SES Global Heaven on December 17, 2002, with a lifespan of 15 years. The geostationary position is 95° west longitude. The satellite has 50 Ku-band transponders, 12 of which are leased by ISRO for Indian DTH operators. Dish TV uses these 12 transponders to transmit their SD channels using MPEG2 compression and HD channels with MPEG4 compression.

AsiaSat 5:

This is a satellite of the satellite communications Asian company, headquartered in Hong Kong, which was launched on August 11, 2009, with a lifespan of 15 years. The geostationary position of 100.5° East. The satellite has 14 Ku-band transponders, four of which were leased by ISRO for Indian DTH operators. Dish TV uses these four transponders for only their HD channels broadcasting with MPEG4 compression.

SES 7:

This is a satellite of SES Global Heaven, which was launched on May 16, 2009, with a lifespan of 15 years. The geostationary position 108.2° east longitude. The satellite has 19 Ku-band transponders, 12 of which are leased by ISRO for Indian DTH operators. Airtel Digital TV uses these 12 transponders to transmit their channels via SD and HD in MPEG4 compression.


Frequently asked Questions about satellite TV:


Q1. With a larger dish, this ensured a better picture quality for the DTH service?

Answer. Larger plate size does not improve the clarity when the signal obtained by the small plate is already at the maximum level. The optimization of the signal power is guaranteed during the installation by the technician of the DTH company.

Q2. Does The MPEG-4 picture quality is poor as compared to the MPEG-2 standard because the signal is compressed?

No, the picture quality is same. MPEG-4 is a newer standard for signal compression with respect to MPEG-2 and allows more channels of transponders to be transported, but the decompression algorithm is also more advanced and the final picture quality is the same as MPEG-2.

Q3. Is the reception of DTH signal impaired or disturbed by environmental factors?

There are two main types of DTH signal interrupts due to environmental factors that are intermittent in nature, with the first "rain break" where there is a temporary loss of signal in heavy rain that absorbs water radiation microsatellite and the second is a phenomenon called " Solar blackout ", which occurs intermittently during the period from February to March and September to October in the equinox when the sunlight dominates and interferes with DTH satellite signals.

We hope this article has been helpful to clarify all your doubts about the different satellites for transmitting DTH signals in India. If you have any further questions, please do so by asking us in the comments below and we will do our best to resolve them as soon as possible.

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