Middle of the road

Posted on 26 Aug 2003 at 15:10

 

Gallery

If you're fed up with your slow dial-up connection but don't have access to broadband internet, there's now an alternative: Midband. Mike James finds out if it moves you closer to the fast lane

You've seen the broadband adverts on TV. Bold, flashy promises of incredible marvels on the internet waiting to be piped speedily into your PC through the use of a broadband connection. It sounds irresistible - but this brave new internet isn't available to everyone. For those who can't get broadband, BT has a new product called Midband.

Broadband is a high-speed, always-on connection to the internet. The most common ways of getting it are through BT's asymmetric digital subscriber line (ADSL) technology, which uses telephone lines, or through the cables used for cable TV and telephone services. In an ideal world we would all have access to broadband but, despite the best efforts of BT and cable companies, many users still can't get it. Although this problem is most serious in rural areas, many users in or close to towns and cities are also denied broadband services.

For over a decade, there's been an alternative method of connecting to the internet that is faster than a modem and available to nearly everyone: integrated services digital network (ISDN). Midband is essentially ISDN repackaged in an attempt to bring faster internet access to the broadband-deprived. So does it provide a worthwhile alternative to a modem? Or should you just wait for broadband to reach your area?

What is Midband?
Midband is based on ISDN 2e, which has been available for years. Almost any phone line can be converted to an ISDN 2e connection simply by fitting a special wall box. This is also the basis for the Midband service. An ISDN 2e line consists of two digital data channels, called B channels, that are capable of sending and receiving data at 64 kilobits per second (Kbit/s). There is also a D or 'dial' channel, which is used to dial the number and generally manage the connection.

The B channels can be used for data or voice communications. However, you can't just plug a computer or an analogue phone into an ISDN digital connector. For standard phone equipment, you need an adaptor to convert the digital line into an analogue line. To make things easier for small business and home PC users, BT offers Business and Home Highway services, which use a slightly larger wall box with two digital connections and standard analogue phone connections.

The BT Midband wall box is the same as that supplied for Home Highway and Business Highway installations after November 2001, which not only includes the usual two phone sockets and two digital sockets but also a USB connector that allows direct connection of a PC without the need for a terminal adaptor. Existing Home Highway users can convert to Midband for no charge, other than adopting the new tariff; Business Highway conversions require an upgrade that costs extra.

Always on time
Although Midband uses the same hardware as ISDN 2e, BT initially tried to make it something more by putting the D channel to additional use. With a little technical innovation, the D channel could make ISDN function as a virtual always-on connection. Always-on is an important feature of broadband. If your connection isn't permanently in touch with the internet, it's like having a phone that you can use to call other people but that they can't call you on unless you happen to pick up the phone at the right time. With an always-on connection you can run applications that provide services on demand to other users such as your own web server and FTP server. This sort of application is likely to play a major part in internet use in the future and depends on users having permanent connections.