Getting connected to the Internet
There are several ways of connecting to the Internet, from a simple dial-up link using a standard telephone line to faster and "always on" connections using a leased line, ISDN, ADSL, ‘cable’, satellite, terrestrial fixed and mobile wireless. The faster the connection the greater its capacity, enabling the fast transfer and download of data across the Internet.
The technological barriers to using the Internet are rapidly coming down, and emerging technologies are predicted to revolutionise the market over the next few years. Permanent connections are eventually expected to predominate in both the residential and business sectors together with access through TV sets, mobile phones, lap-top and handheld computers and all manner of similar devices.
How is the speed of a connection measured?
The type of connection you use has a direct effect on the speed with which you will be able to use the Internet. The capacity of an Internet connection is referred to as its bandwidth, and is measured in bits of data per second, a bit being an on or off, 1 or 0 signal. A thousand bits is a Kilobit (Kb), a million bits is a Megabit (Mb), a thousand million bits is a Gigabit (Gb) etc. However, data files are measured in Bytes, KiloBytes (KB), etc, with a Byte calculated as eight bits.
So, a 1MB file is 8,000,000 bits and, in theory, will take 200 seconds (3 minutes 20 seconds) to transfer over a perfect 40kb/s (40,000 bits per second) connection.
Always bear in mind that your connection is constrained by the slowest component of the network and the amount of data being transmitted across it at the time. Bottlenecks on the other end of the link and even en route may also affect transmission times, and imperfect connections can lead to errors and delays. Some transmission devices and software compress files, reducing the amount of data and transmission time, but additional data is added to the file size by network and transmission protocols.
Using a dial-up connection
A standard telephone line and a modem is the entry-level connection to the Internet. The modem translates the analogue telephone signal into a digital signal recognised by a computer, and the connection is initiated by dialling an ISP's Internet access telephone number. There is generally a local telephone call cost and/or an ISP subscription charge, although charging models are many and various. Data can flow both ways, but only when a connection is live. So e-mail sent to you will only be received the next time you connect to your ISP, and similarly remote Internet users will not be able to access your computer or network unless you have initiated a connection.
Modems may be either an internal PC card or an external box. The standard download speed, the speed at which your computer receives information, is up to 56kb/s, while the upload speed, the speed at which your responses are sent back, is up to 33.6kb/s. Two (or more) modems and telephone lines can be "teamed", brought into operation and dropped automatically according to data transfer demand, to increase the available bandwidth.
With an ISDN line your computer will connect more quickly than with a modem, in around one second as opposed to 20-30 seconds, and data is sent and received at a constant 64kb/s. ISDN connections are also generally more stable. The ISDN equivalent of a modem is a terminal adapter, either an internal card or an external box, which can be plugged directly into an ISDN telephone socket. Two or more channels can be "BonDed" using a multiplexer to increase throughput, creating "bandwidth on demand" and data rates of 128 kb/s upwards, depending on the number of channels available.
Using a permanent connection
A permanent connection is like a permanently open telephone line, with call charges incorporated into your ISP subscription and/or line rental charge. With a permanent connection e-mail can be delivered and received instantly, and other applications such as website hosting and videoconferencing become possible options.
- leased line - runs between you and your ISP. Can be almost any bandwidth in multiples of 64kb/s up to and beyond 2Mb/s, although higher bandwidths are only normally appropriate for ISPs and large organisations. Costs from £500 for installation, plus around £3000 pa rental.
- ADSL - a permanent, high-speed digital connection run on a standard copper phone line, with the added advantage of allowing you to make voice calls at the same time as accessing the Internet. Technically ADSL links can provide a download speed of up to 9Mb/s (upload speed at 640 Kb/s), but bandwidth capability deteriorates with distance from the telephone exchange and the highest practical commercial rate is likely to be 2Mbps/256kbps. Availability is improving and BT claims to be on target to reach 95% of the UK population by the end of 2005. Costs from around £20 + VAT per month plus line rental for a 512/256 kbps service.
- cable TV - connections to the Internet over cable TV networks are available in many parts of the UK. A cable modem costs around £500, but can be leased from the provider as part of the total monthly subscription charge of £20-£60. Cable modem connections are technically capable of download speeds of up to 10Mb/s, with an upload speed of up to 2Mb/s or 10Mb/s depending upon the system, but bandwidth is shared by all concurrent users of the network and individual connections may be capped at 512kb/s or less to differentiate commercial offerings.
- fixed wireless and satellite access technologies are a bit more expensive than ADSL and cable but are gaining ground in areas which are outside the technical or commercially viable reach of such technologies. WiFi (802.11 standard) ‘hotspots’ are springing up in airports, railway stations, hotels, coffee shops etc. where local wireless network connections are available if you have a wireless card in your laptop and a subscription to the relevant service.
Accessing the Internet without a computer
Connecting to the Internet is also increasingly viable using familiar household gadgets, such as a television or mobile phone. Alternative ways of accessing the Internet include:
- via a mobile phone - hard to avoid, the latest mobile phones offer Internet access on the move using WAP (wireless application protocol) and GPRS, and ‘3’ now offer third generation UMTS over a growing network
- via digital TV - the set-top box which brings you a deluge of digital channels will also enable you to browse the Web and send e-mail from the comfort of your own armchair if a telephone line can be plugged in to your set-top box.
- via a games console - Sega's Dreamcast and the Playstation 2 have built-in modems, and are considerably cheaper than a computer
- via your fridge?? – wired, WAP or ‘Bluetooth’ local wireless technology in conjunction with a PC and an always–on connection can make any device Internet-enabled - such as the office security system, your central heating, curtains, lights, video-door-phone-lock-system - and even your fridge so it can automatically re-order when you run out of beer or low fat active yoghurt.
Reviewed June 2007
last updated : 15/06/2007
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