What is GSM?
GSM is a digital equivalent to TACS, but using digitally encoded signals, which are
not prone to eavesdroppers with "scanner" radio receivers. Vodafone and Cellnet
have 900MHz GSM networks in the UK. Both networks are building fast, and GSM is now
as widespread as the TACS systems, if a little more patchy.
What does it cost?
In the UK, calls are charged by the second. The per-minute price varies between 2p and 40p,
depending on the tariff and the time of day. Vodafone have an option to have a
number of "free" minutes airtime each month, like Orange offer, and Cellnet
allow a money-amount of calls "free" each month in exchange for a fixed
monthly fee. Cellnet and Vodafone are persuading TACS customers to switch to GSM.
There are ways to cut the cost of GSM line rental charges. See the Affordable Connections page for details.
Both Cellnet and Vodafone have most of their GSM networks finished, (though both are still adding sites as fast as possible) and are now bringing prices down and features up to attract TACS users across, as they'll want to reuse some of the TACS frequencies in the next few years, some suggest. Technically it is a good service. Good signal strength seems to be needed for clear calls.
There are some capacity problems in certain areas, and it is noticeable how big a difference there is between peak and off-peak call charges. Both Vodafone and Cellnet have some GSM 1800 frequency allocation, although it isn't clear how they plan to use this. It may be for congested areas, or for special in-building coverage.
Can I use it abroad?
There is an international standard GSM for these phones, which means
that they can be used abroad in as many as 70 countries (but not the USA, which uses a
different frequency, or Japan), and calls automatically get transferred -- at a price!
The way it works at present means that you pay for an international call diversion at
cellular rates, plus a 35% markup. Credit checks and/or a period as a UK subscriber
may be needed before international roaming is made available to you. The advertising tells
you a different story, but that's advertising ...
cellular. v1.52 23 Nov 1999