Datacasting

Source: Wikipedia, the free encyclopedia.

Datacasting (data broadcasting) is the

direct broadcast satellite system, or to things like cable modems or satellite modems, which use a completely separate channel for data.[1]

Overview

Datacasting often provides news, weather forecasting, traffic reporting, stock market, and other information which may or may not relate to the carried programs. It may also be interactive, such as gaming, shopping, or education. An electronic program guide is usually included, although it somewhat stretches the definition, as this is often considered inherent to the digital broadcast standard.

The

EUREKA 147 and HD Radio standards both allow for datacasting on digital radio
, defining a few basics but also allowing for later expansion.

The term IP Datacasting (IPDC) is used in

UMTS
. The set of specifications for IP Datacast (phase1) was approved by the DVB project in October 2005.

Datacasting services around the world

North America

Ambient Information Network

Ambient Information Network, a datacasting network owned by Ambient Devices presently hosted by U.S.A. Mobility, a U.S. paging service which focuses on information of interest to the local (or larger) area, such as weather and stock indices, and personalized information will be provided with a paid ambient subscription on that particular device.

RBDS

A slight variation of the European

dGPS
.

DirectBand

error correction
) of data per station, for over 100 MB per day per city. Data includes traffic, sports, weather, stocks, news, movie times, calendar appointments, and local time.

MovieBeam

The now-

analog TV. The set-top box stored the movies to be viewed on demand for a fee. This was distributed through PBS's National Datacast
.

TV Guide On Screen

TV station, which is already mandated by the U.S. Federal Communications Commission
(FCC).

ATSC-M/H

ATSC MPEG transport stream used for terrestrial television
broadcasting. Heavy error correction, separate from that native to ATSC, compensates for ATSC's poor mobile (and often fixed) reception.

UpdateTV

over-the-air programming
. This is also transmitted on PBS stations via National Datacast.

Australia

See also: Digital television in Australia

Australian broadcast infrastructure company

Broadcast Australia undertook a three-year trial in Sydney of a datacasting service using the DVB-T
system for use in Australia.

The trial consisted of a number of services on one standard 7 MHz

multiplex, collectively known as Digital Forty Four
.

The collection included:

More recently a near-Australia wide broadcast of a datacasting channel called

Southern Cross Ten
station.

On February 25, 2008, MyTalk ceased broadcasting. Digital Forty Four was shut down at exactly midnight on the night of April 30, 2010.

Malaysia

Malaysian multi-channel pay-TV operator,

MiTV Corporation Sdn Bhd
launched its IP-over-UHF service in September 2005. The full digital broadcast capacity was used to deliver IP services which such as multicast streaming and datacasting.

Middle East

Toosheh, or "Knapsack" in Persian is a datacasting technology that uses existing set-top-boxes for reception of files without requiring an Internet connection. No special equipment is required, the transmission is in the form of a standard video stream containing embedded data that is 'recorded' to a USB stick and then viewed using special software on a PC.

South Africa

Mindset Network has developed an IP satellite datacast platform for the distribution of educational and health content, to sites around South Africa and the rest of Africa as well. The model is a forward and store model, allowing users of the platform to view content in an on-demand fashion. Content distributed in this way includes video content, print-based content (in the form of PDF files), and interactive computer-based multimedia content.

Significantly, the model also includes access to a GPRS network that allows the receiving sites to communicate back to the Mindset central server. Communications include statistics about the physical health of the machine (e.g. power status, disk drive usage), as well as usage statistics indicating what content has been viewed.

The model also includes a distributed deployment of the Moodle LMS, allowing users to take assessments and have the results transmitted via GPRS to the Mindset server for accreditation.

United Kingdom

Teletext was used extensively on analogue channels; a type of datacasting using the overscan on analogue transmissions. Teletext Limited and Ceefax were the main providers. Within digital terrestrial television, the Digital Teletext name is used extensively although the technology used to provide this service is unrelated and uses the MHEG-5 UK profile.

Worldwide

Blockstream Satellite

Blockstream Satellite broadcasts the Bitcoin blockchain via a global network[2] of broadcast satellites. It also gives everyone the ability to transmit arbitrary files at low cost[3] which can be received in total anonymity worldwide by anyone with a standard DVB-S2 receiver card or USB adapter.

Outernet

hotspots
, which receive data broadcasts from satellites.

Advantages over Internet transmission

Datacasting has certain advantages over using the Internet, specifically concerning privacy and censorship resistance, which can be considered important in an era of mass surveillance.

Both satellite and terrestrial broadcast multiplexes can carry multicast IP data. This can be forwarded onto a LAN with a suitable receiver, such as a low-cost set-top-box running custom firmware. The software to transmit web pages over multicast is fairly easy to implement; some of the technology has been already developed.[4] Content received can be stored automatically on the set-top box's built in hard drive, served to users over Wi-Fi or Ethernet. A fractional broadcast multiplex can transmit up to hundreds of gigabytes of content each day.[5]

Privacy

Because the data stream is receive only, nobody can tell what a user is receiving. Thus the government cannot round up citizens for reading forbidden material in oppressive regimes. In extreme cases the receiver can be

Tor. This could ultimately put a complete stop to law enforcement attempts to censor material on the darknet
and making many censorship laws virtually impossible to enforce; thus restoring some of the 'anarchic freedom' of the early days of the Internet.

Censorship

It is much more difficult, on a technical and political level to jam a satellite signal compared to blocking a website. Data streams can be transmitted alongside television channels. An attempt to jam the data stream will end up jamming the TV stations as well.

Efficiency

Despite the very high cost of satellite bandwidth,[6] broadcasting to hundreds of thousands or millions of receivers may well be cheaper than using the Internet. No build-out and maintenance of costly physical infrastructure (e.g. fiber optic cables) is required for the end-user, only a satellite dish or TV antenna is necessary, allowing services such as educational materials to be delivered to underserved communities.[7]

See also

References

  1. ^ "Datacasting | Homeland Security". www.dhs.gov.
  2. ^ "Blockstream: Satellite Network Coverage". Retrieved 30 July 2021.
  3. ^ "Blockstream: Satellite Queue". Retrieved 30 July 2021.
  4. ^ "ATSC 3.0 Interactive Content" (PDF). ATSC. Retrieved 31 July 2021.
  5. ^ "ATSC Datacasting Paves Way for Flexibility of ATSC 3.0 in Distance Education". February 2021. Retrieved 31 July 2021.
  6. ^ "Satellite Internet Costs – transponder and VSAT equipment prices". Retrieved 31 July 2021.
  7. ^ "Innovations in Distance Education: Datacasting". Retrieved 30 July 2021.
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