Broadband ISPs
Broadband relates to high-speed internet connections, generally the type that a home user can take advantage of. This does not include leased lines and ISDN. Broadband is split into 3 distinct types:
We have also included wireless access, but this is still in its infancy, and is heavily restricted by location.
ADSL
ADSL stands for 'Asymmetric Digital Subscriber Line' and turns your phone line into a dual telephone / high speed internet connection. For this to be achieved, the type of signal sent through your phone line needs to be converted into a DSL signal, which contains both the phone line line signal and your internet signal. A device called a microfilter which plugs into the phone socket splits the two signals so you can use your telephone at the same time as the internet. The 'Asymmetric' means that your download and upload speeds are not the same. Usually the upload speed is around half that of the download speed, but can also be fixed at around 256Kbps (Kilobytes per second).
ADSL is currently limited to customers with a BT line, who have had their local exchange upgraded by BT. You can check to see if you can use ADSL on BT's website. In addition, you need to pay to have your phone signal converted to ADSL, which is generally around £60. Microfilters will have to be plugged into every phone socket that use the same line, costing around £8-12 each.
Most ADSL ISPs will offer you the choice of a self-install or an engineer-installed connection. The engineer-installed option is usually considerably more expensive, and consequently it is recommended you install it yourself.
Cable
If you subscribe to a cable TV company, such as NTL or Telewest, you can use your cable connection to connect to the internet. Every TV channel through cable has a dedicated bandwidth 'slice', and one or more of these channels can be used to send and receive data for internet access.
Your cable company will normally charge you a setup fee (around £50) to activate these channels, and will usually loan you a cable modem for your computer as part of your monthly fee.
Note that you will have to have digital cable in order to access the internet. Cable customers who are subscribed to the older analogue services will have to upgrade to digital first.
Satellite
Satellite internet is a relatively new broadband solution which is of most use to people living in rural areas who have not had their telephone exchange upgraded to DSL, and are not served by a cable company. With satellite access, your computer receives and (in some cases) sends information through your satellite dish, to the company's Network Operations Centre (NOC) by means of a satelite.
There are two types of satellite access, synchronous and asynchronous. With synchronous access, your satellite dish can both send and receive data, but with asynchronous access, your satellite dish can only receive data from the NOC. It is therefore necessary with asynchronous access to have an extra dialup account for outgoing data, so note that in this case, broadband will still hog your phone.
Satellite access is usually quite expensive, and, as some companies require you to have their own satellite dishes, difficult to install. Another drawback is that broadband gamers may find slight delays happen periodically during a game session, as there is a delay in the data being transmitted to and from the NOC. You would not notice these delays while browsing the internet, but internet computer games usually have to send and receive a lot of data each second.
Wireless
Although wireless access is not strictly a new technology and is being utilised in many places, it is still not practical for the home user due to the low range involved. Wireless access is currently more suited to wireless local area networks (WLAN) in order to remove the troubles of installing LAN access points and cables. Despite this, there are a few companies who have installed wireless access points in public areas to create a 'hotspot', and can then charge for their usage (such as BT's OpenZone). Users can pay a subscription fee, or buy a certain amount of connection time, and then take their laptop to the hotspot to connect to the internet. Many of these hotspots are in hotels, to facilitate business users while they are away from the office, but T-Mobile are also beginning to install hotspots in StarBucks cafes for casual net users to log on while enjoying a coffee.
Some companies / users who use a wireless access point may also deliberately leave it open for users to connect to. People will wander around a city using their laptop to detect one of these open networks, and can then log on to the net in a process known as 'Wardriving'. Once they have finished using the open network, they may chalk symbols onto the pavement or a wall to indicate to other users that there is an open network in the area. This is known as 'Warchalking'. It is important to note that some companies may accidentally leave their network open, and could consider your usage of their systems a hack attempt.
To connect to a wireless network, you will need an 802.11 compliant wireless network card, and a laptop (unless you live within a hotspot, in which case you can use a desktop machine). CCL Computers sell a variety of wireless equipment, including wireless network cards.