What is broadband?
High quality 'always-on' access is just one manifestation of the
thing called 'broadband'. But 'broadband' means more than having
a permanent connection to the internet. It is the technology that
underpins the new digital forms of communication which are already
beginning to impact on our day-to-day lives.
The broadband market refers to two elements: broadband distribution
and broadband content. Broadband content often refers to data, voice
and/or video, which alone or in combination require high transmission
speeds. Examples may include high definition movie trailers, short
films, flash animation, three-dimensional video games, video on
demand, MP3 files, internet radio, streaming video, videoconferencing
and so on.
Broadband in the context of the internet is most often used to
refer to bandwidth. The greater the bandwidth, the faster one can
transmit information from one point to another. The level of bandwidth
of a particular transmission is most often measured by the amount
of digital bits that one can transmit per second. A byte is a number
of bits and is measured using metric prefixes: a kilobyte, a megabyte,
a gigabyte and so on. Certain types of content and applications
require a certain amount of bandwidth in order to be viewed, listened
to, or to function at an optimal level.
Apparently to broadcast content at TV quality, one needs between
6-8 megabits per second of bandwidth. If you don't have bandwidth
that will allow you to transmit 6-8 megabits of data per second,
then the quality of the transmission will be affected. For example,
the sound or picture quality may deteriorate. So while the definitions
for broadband can differ in how many Kbps or how many Mbps, it does
pay to be familiar with the various terms.
Internet Services - About ADSL
ADSL - An Overview
ADSL stands for Asymmetric Digital Subscriber Line. A twisted copper
pair of wires are transformed between a local telephone exchange
and a Customers telephone socket into a high-speed digital line.
ADSL is not unlike a standard Kilostream connection as in there
are no additional telephone calls and this is an 'always on' service.
ADSL is exchange dependant and the speed can not be guaranteed.
You can have access to the Internet whilst utilising the same line
for say faxing or having a telephone conversation. Most of all you
are always connected so there's no dialing up required and therefore
no phonebill.
This is called "asymmetric" because it moves data more
quickly from the exchange to customer than it does from the customer
to the exchange. This technology is thus particularly suitable for
applications where customers expect to receive more data than they
transmit i.e.: using the World Wide Web, Intranets, and use of digital
audio-visual material.
ADSL allows dedicated bandwidth that can be up to 62 times faster
than ISDN. In addition, this technology uses your ordinary phone
line but doesn't restrict use or tie up the line.
ADSL - FAQ's
How fast is ADSL ?
ADSL comes in three flavours, providing variable speeds to allow
users to best match requirements to budgets.
ADSL S500 allows 256k upload and 500k download
ADSL S1000 allows 256k upload and 1Mb download
ADSL S2000 allows 256k upload and 2Mb download
This is 10 to 40 times faster than today's typical modems.
How does ADSL work?
ADSL operates over a standard telephone line. The signal is carried
by two ADSL modems - one in the local exchange and one in the clients
premises. The modems are designed in a such way as to utilise fully
the capabilities of the copper line therefore achieving much higher
data rates. A 'splitter' separates the signal from the ADSL sign,
meaning that telephone calls can still be made at the same time
as data is being sent or received.
What can it be used for?
Internet access - The access speeds available with ADSL
make it practical for web sites to carry more multimedia rich information
such as embedded video clips, animations and good quality audio
- significantly enhancing the online experience Intranet access
- Fast access to the Intranet makes teleworking an attractive option
- which in turn can bring benefits to both the organisation and
the individual TV based services - ADSL can be used to deliver interactive
applications to the TV, such as real time video and audio, home
shopping and home banking
Future services - ADSL will be the catalyst for a wealth
of new information, education and entertainment services
Who will be able to take advantage of ADSL ?
The local exchange needs to have been provisioned with ADSL capability.
There is a phased roll out in place, which means that not everyone
will be in a provisioned exchange area location.
Because ADSL is distance dependant, the end user needs to be located
within a certain distance of the exchange. This distance is typically
3.5Km and approximately 80-85% of the UK live within this distance
of their exchange.
So where is ADSL available?
The service is available from over 400 exchanges including the following
locations: Birmingham, Belfast, Cambridge, Cardiff, Coventry, Edinburgh,
Glasgow, Leeds, London, Manchester, Milton Keynes and Newcastle.
Over 13 million UK households can benefit from the advantages of
ASDL technology, but can you get it? Well, as different providers
offer coverage in certain areas you will have to check the availability
with them.
What coverage is provided?
It has been said that with all the providers put together they would
cover approximately (75%) of UK homes. The availability of ADSL
services at a specific location is subject to technical limitations
and survey. Service availability in any given area is constrained
geographically and is subject to change.
All of the providers we link to from our site allow you to check
via your postcode to make sure the service is available before continuing
with your application.
