Broadband FAQs
- What is broadband?
- How does broadband work?
- What are the different types of broadband?
- What are the main benefits of broadband?
- How fast is broadband compared to a standard dial-up connection?
- Can anyone get broadband?
- Can I get broadband where I live?
- What is broadband contention?
- Can I upgrade from ISDN to broadband?
- Should I convert my leased line to broadband?
1. What is broadband?
Broadband is the term used to describe a wide range of technologies that enable high-speed, always-on access to the Internet.
Broadband or ADSL (Asymmetric Digital Subscriber Line) is a technology for transmitting digital information at a high bandwidth on existing phone lines to homes and businesses. Unlike regular dial-up Internet services, ADSL provides a continuously available, "always on" connection.
ADSL is asymmetric in that it uses most of the channel to transmit downstream to the user and only a small part to receive information from the user. It was specifically designed to exploit the one-way nature of most multimedia communication in which large amounts of information flow toward the user and only a small amount of interactive control information is returned.
In simple terms, the higher bandwidth available (up to 2Mb) transforms an existing telephone wire into a high-speed digital line capable of carrying data at up to 40 times the speed of a conventional modem. This allows you to gain the advantages of high-speed Internet access and data transfer without the cost implications of having a separate dedicated line installed.
2. How does broadband work?
Broadband service makes use of your existing BT telephone line by splitting the line into two distinct channels: one for voice and the other for the high-speed data connection. The high-speed data connection uses a higher frequency range not used in normal voice communications.
The broadband signal is carried by two specialised modems - one at the user end and one in the local exchange. These modems are designed to exploit the physical transmission capabilities of the copper line to achieve higher data rates over the line than ever before.
A 'splitter' (which is basically a filter) separates the telephony signal from the data signal at the user end and at the exchange end. This allows telephone calls to be made at the same time that data is being sent or received (i.e. a customer can surf the Internet and still make telephone calls), removing the need for customers to purchase a second line solely for Internet access.
3. What are the different types of broadband?
DSL (Digital Subscriber Line) technologies
DSL technologies enable broadband services to be delivered over the existing copper loops that extend into all households and businesses that have a fixed telephone line, but the technology is only effective when used over relatively short distances (about 3km from the local exchange). DSL technologies generally offer users speeds ranging from 256 kbps to 10-20 Mbps.
Cable modems
Cable networks offer a supply route for higher bandwidth services to both the residential SME and the large business market. A cable modem offers a similar speed to basic ADSL services (c. 500 kbit/s).
Fibre
Fibre installed direct to a consumer's house or to a business premise will provide higher bandwidth access with delivery rates above those achievable with DSL technologies. Installation of fibre to replace the copper loop is expensive and, at least in the short term, there is unlikely to be widespread installation and deployment of fibre direct to low volume customers' premises although the use of fibre to distribution points (e.g. street cabinets) may become economic over time.
Satellite
Satellite provides all of the functionality of fixed line broadband with the added advantage of being capable of reaching remote rural areas where other types of provision may not be technically feasible or economically viable.
Leased lines
Leased lines are permanent telecommunications links supplied by network operators to users, which provide capacity dedicated to the user's exclusive use. They are used by large businesses and some SMEs to carry high volumes of voice and data traffic. They are also used by other telecoms operators and service providers and so underpin many other services and provide the 'backbone' for the mobile networks. Internet Service Providers use leased lines to connect to the Internet and to offer high speed Internet access to business consumers.
Fixed wireless access
Broadband fixed wireless access allows users to take advantage of cheap, fast Internet and multimedia access through radio links rather than down a telephone line. The Government held an auction in November 2000 of spectrum in the 28 GHz bands that can support two-way higher bandwidth and broadband services. The regions where licences were sold cover 57 per cent of the UK population and include both Scotland and Northern Ireland, areas where there has been particular concern about possible supply problems.
3G
Radio spectrum has been allocated for 3G mobile services which will provide higher bandwidth services and in certain circumstances may support data rates up to 2Mbit/s.
4. What are the main benefits of broadband?
By exploiting a higher bandwidth, broadband enhances not only your current user experience but also provides you with access to entirely new online opportunities. Broadband can totally change your perception of the Internet and the way in which you use it. Outlined below are just some of the possibilities available:
Increased web browsing and file transfer speeds
The access speeds available with broadband make browsing the web and downloading large files extremely easy. Files that once took hours to download now take just a few minutes.
Improved Internet experience
The speed of a broadband connection makes it more practical for web sites to carry multimedia rich content such as videos, animations and audio, thus enriching your online experience.
Reduced waiting time
Users no longer have to wait to connect, as broadband connections are permanent and 'always on'. Users can send and receive emails in 'real time' and connect to the Internet instantly.
Support for Virtual Private Networks (VPN)
In its simplest form, a VPN is a private connection between two machines or networks, over a shared or public network. In practical terms, VPN technology lets an organisation securely extend its network over the Internet to remote users, branch offices, and partner companies.
Empowered home workers
The improved access speeds and unmetered service provided by a broadband connection provide an ideal solution for employees working from home. Not only can they browse the web at speed and send/receive emails instantly, but it also provides them with the capability to access a corporate Intranet without travelling in to work.
Improved e-business opportunities
Whilst it has become normal for businesses to have a presence on the web, it is becoming increasingly important for them to sell their products and services online too. A broadband connection can assist with getting your e-commerce web site 'up and running' by offering a robust, high speed Internet connection on which to host it. It also allows you to regain control of your business, by bringing mail and web servers in house.
Reduced costs
Broadband tariffs are fixed and unmetered. Regardless of how long you spend accessing the Internet you will be charged a flat monthly fee. This improves your ability to forecast expenditure.
Improved IT operations
A broadband connection enables businesses to take advantage of applications delivered remotely over the Internet via application service providers (ASP's). ASP's enable organisations to benefit from the latest software and IT support without having to have their own IT department or systems administrators.
5. How fast is broadband compared to a standard dial-up connection?
Broadband is up to 40 times faster than traditional 56k modems. In addition, broadband provides a permanent connection that is always on.
6. Can anyone get broadband?
In order to get broadband, BT must have upgraded your local exchange and you must be located within 5.5km of it.
Approximately 70% of UK homes and businesses are currently within range of a broadband enabled exchange and the coverage is continually expanding.
If your exchange is not broadband enabled then BT are running a demand based pre-registration scheme, whereby they promise that your exchange will be upgraded providing those on an exchange can show sufficient demand.
7. Can I get broadband where I live?
To determine whether your local exchange has been broadband enabled, please go to www.bt.com.
8. What is broadband contention?
Contention refers to the number of different users that could be simultaneously using the same broadband access feed as you. In simple terms, contention refers to the number of users that might be sharing your link.
At present there are two contention rates for the BT network (50:1 and 20:1). What this means in the worst case is that you could be sharing a 500 Kbit/s connection with up to 49 other users. Therefore, if they were all using it at the same time you would only get 10 Kbit/s. However, in reality this scenario is very unlikely to happen and you should usually find it to be far faster than a modem connection.
9. Can I upgrade from ISDN?
It is possible to cancel your ISDN subscription and upgrade to broadband. However, your ISDN line would first need to be converted back to analogue.
10. Should I convert my leased line to broadband?
In the majority of circumstances, it is usually preferential to continue with a leased line. Although broadband is an always on service, it is contended to at least 20:1. A leased line provides a dedicated, un-contended service and consequently offers a level of mission critical stability that broadband is unable to match.
