Data connections from a mobile phone allows email, data transfer and web connectivity to be available from anywhere the phone will work.
There are a couple of TACS phones that take a special data connector, and it works, albeit with some difficulty, generally at speeds of only 2400 or 4800 bps. GSM phones are rather different. The GSM specification (which both systems follow) allows for data at 9600 bps (the spec allows 14,400 bps in fact), and there are phones available that support this. All the UK digital networks now offer some data service, though only Orange at 14.4.
On the digital networks, using a modern handset 9600 bps connections are possible, using a data connector that costs rather a lot of money - see below. You won't ever be able to use a GSM phone with an acoustic coupler and get even half-decent results, as the way the speech is encoded ruins modem tones.
Orange have linked up with Demon Internet and with Pipex Dial to offer internet access from Orange phones, which gives faster connection (handy for collecting email) and an Orange number to dial - although many people may find Demon's 0845 number more useful, as it doesn't use up the inclusive airtime.
The Nokia 9110 is a PDA with built-in browser and cellphone, but it costs several hundred pounds at the time of writing, and is a bit bulky. Web browsing is slow at 9600 anyway, but for email, I suppose it could be useful. If anyone fancies buying me one...
More affordably, the data adapter for Nokia phones costs 200 pounds, or if you have one of the latest Nokia phones, you can buy the Nokia Cellular Data Suite for around 100 pounds, which provides phone book maintenance, SMS, data and fax connections using the serial port of a PC running Windows 95. I like it! The 6110 series has an infra-red port, so works without the cable.
The latest generation of Nokia phones (the 8210 and 6210 series) have a full data implementaion, and do not need special software on the computer. The latter supports data at 14.4 or 28.8 if the network supports it. (So far, only Orange support it, and it costs an extra £5 per month, and it is only available to contract customers who are not on ED50.
The latest generation of phones (for example, the latest Ericssons, Siemens S25 and S35) have all the data functionality and infra-red built in. The 7110 has a sort of mini-browser, which uses a special protocol called WAP to fetch information pages (note that the otherwise nice Siemens S25 uses an obsolete version of WAP). This is so new at present that there isn't too much to look at yet, and some handsets are still in short supply.
Fax and data calls are included in the "free" inclusive airtime on Orange. The system is good. You get an additional fax number and data number as well as your voice number(s) at no extra charge! If you don't have you phone connected to your computer when a fax comes in, you can divert it to your fax mailbox.
Virgin don't give you extra numbers, so you can only make outgoing fax and data calls, and not receive them, but 0800 data calls are supposed to be charged for (but don't seem to be at present!).
One2one and Orange now charge for data calls to 0800 numbers, though they have failed to tell their customers properly.
If you expect to make alot of off-peak internet calls, BTInternet offer an unlimited off-peak acces package for £9.99 per month, but unless you use 1,000 minutes or more every month, OneTel.net are better value.
OneTel.net offer internet access on a (free) 0808 number, and charge you 1p per minute, including VAT. I've found it to work well enough. You can sign up for onetel.net at their web site at http://www.onetel.net.uk/.
There is also Public OnLine, who offer an 0800 access number, currently charged at 3.3p/1.5p/1p per minute peak/evening/weekends. Contact them at http://www.bizonline.net or http://www.publiconline.net and please quote reference PA26 so they know I suggested them to you. It seems to take a week or so to get connected, even after you've returned the paperwork, but it is worth the wait if you want internet access on an 0800 number.
Comments, suggestions and amendments welcomed!
cellular. v1.60 10 Dec 2000