General Packet Radio Service is form of high-speed connection for mobile phones. It allows users to send and receive email, browse the mobile internet and send enhanced text messages faster than can be done with a conventional GSM connection.

GPRS provides considerably improved download times for accessing WAP pages and for sending emails. Unlike standard internet connections, the GPRS connection is 'always on'. The connection is permanent so there is no need to wait while your phone dials a connection each time you want to use it. You just have to log on when you switch your phone on (this usually takes about ten seconds, as opposed to around 30 seconds for a typical GSM modem connection). It also allows you to make a voice call while simultaneously transferring data. Instead of charging by the minute, GPRS users are charged by the amount of data they download - typically, you are charged for each WAP page you view (though not necessarily connecting menus in-between). This can lead to savings if you spend a lot of time browsing the text-based mobile internet, however browsing the world wide web with GPRS (which can be done using a mobile phone and compatible PDA or laptop) can become extremely expensive very quickly because of the more data-intensive web pages. GPRS is essential for the new MMS (Multimedia Messaging Service). Conventional connections would make transmitting high-data picture files too costly and too time-consuming.

Traditional GSM connections work by establishing a link between two points, whether that be another mobile phone for voice or text messages, a server for the mobile internet or a PC for email or instant messaging. GPRS works by combining pieces of data into groups, called 'packets' which can then be sent by whichever channels are available. The packets are then reassembled at their destination. The data capacity of anything up to eight channels can be utilised as and when needed (the actual amount varies depending on the network and handset, but four channels for receiving data and one for sending is fairly common).

Typical data speed on a GSM connection is 9.6kbps - which is roughly a fifth of a standard home internet connection from a PC using a 56K modem. GPRS typically increases that connection to 38.4kbps - still short of a home connection, but a big increase on the standard digital connection. Since WAP sites tend to be fairly stripped down anyway, with a minimum of graphics, this is fine for accessing the mobile internet. Connection speed is however also dependent on network capacity.

Voice calls take priority over whatever channels are available and data transfer can slow considerably if the network is particularly busy. As yet, you still cannot access the full internet with just your mobile phone alone (the screen isn't big or detailed enough to view web pages), though you can with some connected PDAs (see HP Jornada 928 and Palm Tungsten W) or by connecting your phone to a PDA or laptop. All the major networks now offer tariffs which will allow you to browse the internet in this way.

There is a steadily increasing list of phones which are compatible with GPRS. Check with your local retailer for a full list.

Even faster data speeds are promised by the arrival of 3G networks, the first of which could be with us by the end of the year. While there's no doubt that 3G offers incredible possibilities, there is also no chance that it will take over from GPRS overnight. Indeed, it's such a mammoth task for the various networks to get 3G infrastructure in place, it's unlikely that it will be a serious alternative to today's services for at least a couple of years.