Set top boxes
A set-top box is the device that enables a TV set to become a user interface to the Internet and also enables a TV set to receive and decode digital television (DTV) broadcasts.
DTV set-top boxes are also defined as receivers. A STB is needed to the viewers willing to receive digital broadcasts via the Internet.
You can do a lot of things using a STB like: receiving and displaying TV signals, connect to different networks, playing games using the popular consoles available on the market, browse the Internet, send e-mails, and access videoconferences. A lot of set top boxes are compatible with camcorders or DVD’s. They may have integrated hard drives capable of storing a very large archive.
They are really easy to use, a user just plugs the STB into the aerial and TV set via composite, component or S-video cable. For the audio part you can plug it to your VCR or sound system. The box is scanning and return the available tv channels. The stream is then received and decoded so the analogue TV can recognize it . .
This type of service, when you are using a set top box may be through a TV cable company or telephone line.
Connecting the Set Top Box
Connect the coaxial cable from the cable outlet into the input on the set top box.
Plug the end of an RCA cable (yellow, white and red) into the set top box output and the other end into the TV’s input.
Power on the set top box on and select the input of the TV (may be AV1 or AV2) to be able to view the content loaded on the set top box.
Here is a common set top box back panel:
1. AC Input – From mains power supply
2. Telephone line Connector RJ11
3. UHF Modulator – For connection to main TV and optional
connection to second TV
4. TV A/V SCART – Provides either composite or RGB and
composite video output. Audio volume can also be controlled
5. VCR A/V SCART – VCR Scart for connection to Video Recorder
6. Analogue Audio Outputs – used for integrating the STB to the home audio system
7. S-Video Connector – gets high quality connection to plasma
monitors or VHS Recorders
8. SP-DIF – connection to home Dolby Digital amplifier
9. RS232 – Serial port connector (used for service)
10. RF Input – Twin IF inputs
A common digital set-top box has one or more microprocessors integrated to run the OS (operating system – like Windows or Linux) and for parsing the MPEG transport stream. RAM, decoder chips may be also STB components.
The most popular TV set-top box is the one which receives encoded digital signals from a source and decodes them converting into analog signals.
Set-top boxes may be associated with these major categories.
1. Broadcast TV Set-top Boxes – (Thin Boxes) – A set-top box with no back channel (return path.)
2. Enhanced TV Set-top Boxes – (Smart TV Set-top Box, Thick Boxes) – have a back channel (return path) through a phone line. May support VOD, e-commerce, Internet browsing, e-mail.
3. Advanced Set-top Boxes – A fully integrated set-top box with good processors, memory and software applications. A high speed internet connection is needed to propely use them.
4. Sidecar – The difference between this type of STB and the other is that it provides an additional transport stream of data from the network operator to support the main stream.
5. Hybrid Digital Cable Box – This is a specialized and more expensive cable TV set-top box compared to the previous models.