A set-top box (STB) or set-top unit (STU) is an information appliance device that generally contains a TV-tuner input and displays output connects to a television set and an external source of signal, turning the source signal into content in a form that can then be displayed on the television screen or other display device. They are used in cable television, satellite television, and over-the-air television systems, as well as other uses. FEATURES OF SET TOP BOX Programming features: 1. Electronic Program Guide Electronic program guides and interactive program guides provide users of television, radio, and other media applications with continuously updated menus displaying broadcast programming or scheduling information for current and upcoming programming. Some guides, such as ITV, also feature backward scrolling to promote their catch-up content.[ 2. Favourites This feature allows the user to choose favourite channels, making them easier and quicker to access; this is handy with the wide range of digital channels on offer. 3. Timer The timer allows the user to program and enable the box to switch between channels at certain times: this is handy to record from more than one channel while the user is out. The user still needs to program the VCR or DVD recorder too. 4. Scart link recording The user having selected the required TV programs on the electronic program guide at the appropriate time, the box sends a control signal via the Scart link telling a compatible VCR or DVR to start or stop recording. This means the user has only to program the set-top box and it will switch to the right channel at the right time and "wake up" the VCR or DVR to record, so there is no need for a timer. Convenience features: 1. Controls on the box Some models have controls on the box, as well as on the remote control. This is useful should the user lose the remote or if the batteries age. 2. Remote controls that work with other TVs Some remote controls can also control some basic functions of various brands of TVs. This allows the user to use just one remote to turn the TV on and off, adjust volume, or switch between digital and analog TV channels or between terrestrial and internet channels. 3. Parental locks The parental lock or content filters allow users over 18 years old to block access to channels that are not appropriate for children, using a personal identification number. Some boxes simply block all channels, while others allow the user to restrict access to chosen channels. SOFTWARE ALTERNATIVES As complexity and potential programming faults of the set-top box increase,[8] software such as Windows Vista's Media Center, Myth TV, and Select-TV have developed features comparable to those of set-top boxes, ranging from basic DVR-like functionality to DVD copying, home automation, and housewide music or video playback.

1. SET-TOP BOX
INTRODUCTION
A set-top box (STB) or set-top unit (STU) is an information appliance device that generally
contains a tuner and connects to a television set and an external source of signal, turning the source
signal into content in a form that can then be displayed on the television screen or other display
device.
Set-top boxes can also enhance source signal quality. They are used in cable television and
satellite television systems, as well as other uses.
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FEATURES OF SET TOP BOX
Programming features:
1. Electronic Program Guide
Electronic program guides and interactive program guides provide users of television, radio,
and other media applications with continuously updated menus displaying broadcast
programming or scheduling information for current and upcoming programming. Some guides,
such as ITV, also feature backward scrolling to promote their catch-up content.[
2. Favourites
This feature allows the user to choose favourite channels, making them easier and quicker to
access; this is handy with the wide range of digital channels on offer.
3. Timer
The timer allows the user to program and enable the box to switch between channels at certain
times: this is handy to record from more than one channel while the user is out. The user still
needs to program the VCR or DVD recorder too.
4. Scart link recording
The user having selected the required TV programs on the electronic program guide at the
appropriate time, the box sends a control signal via the Scart link telling a compatible VCR or
DVR to start or stop recording. This means the user has only to program the set-top box and it
will switch to the right channel at the right time and "wake up" the VCR or DVR to record, so
there is no need for a timer.
Convenience features:
1. Controls on the box
Some models have controls on the box, as well as on the remote control. This is useful should
the user lose the remote or if the batteries age.
2. Remote controls that work with other TVs
Some remote controls can also control some basic functions of various brands of TVs. This
allows the user to use just one remote to turn the TV on and off, adjust volume, or switch
between digital and analog TV channels or between terrestrial and internet channels.
3. Parental locks
The parental lock or content filters allow users over 18 years old to block access to channels
that are not appropriate for children, using a personal identification number. Some boxes
simply block all channels, while others allow the user to restrict access to chosen channels.
SOFTWARE ALTERNATIVES
As complexity and potential programming faults of the set-top box increase,[8] software such as
Windows Vista's Media Center, Myth TV, and Select-TV have developed features comparable to
those of set-top boxes, ranging from basic DVR-like functionality to DVD copying, home automation,
and housewide music or video playback.
STB software has two parts.
 System software which provides the DAVID application programming interface.
Application software that provides cable TV functionality or some other personalized multimedia
service
ADVANTAGES OF SET-TOP BOX
set top box gives more picture & sound clarity
it may be mpeg4 or HD
in HD set top boxes it gives powerful surround sound&5times sharper picture than mpeg4.
It enables to play games on TV without a disc or software

2. It gives more number of channels
Parental locks
Recording options
Organized channels
Forward and rewind play stop option
DISADVANTAGES OF SET-TOP BOX
In heavy rain or bad weather, signals can disrupt.
Power bill higher
Channel changing is slower
Every tv needs individual set top box