Third-generation (3G) mobile service provider 3 is continuing to attract criticism for the poor quality of the high-speed data services it offers in the UK.

Rival mobile operators have said they will wait for improved 3G handsets before launching commercial networks of their own, and some carriers are even looking at other high-speed mobile technologies as an alternative to 3G.

The 3 service, which launched in March, received more customer complaints than any other mobile service between 1 April and 1 October, according to recent Oftel figures, with 2.97 complaints for every 1,000 customers.

Next on the list were T-Mobile, Orange and O2, which received 0.2 complaints for every 1,000 customers.

The most common complaints were dissatisfaction with 3's customer service and support, poor network coverage and short handset battery life.

Battery life is an important issue for wideband code-division multiple access based 3G phones that feature large colour screens and other multimedia capabilities that quickly drain power.

Speaking to investors at a meeting in Barcelona, O2 chief executive Peter Erskine emphasised that the availability of suitable handsets would be the crucial factor in delivering successful 3G services.

"The reason why the rest of the industry is launching 3G in the second half [of 2004] is that really decent handsets that are not battery-life hungry will not appear until October 2005," he said.

O2, Vodafone, Orange and T-Mobile are scheduled to launch their first 3G services in the UK towards the end of 2004 or early in 2005, although coverage may initially be limited to specific regions or cities.

In the early stages, user numbers might also be restricted by the limited availability of suitable new 3G handsets from manufacturers like NEC, Motorola, Sony Ericsson and Nokia.

If the schedules slip further, carriers may decide to launch next-generation high-speed wireless data services using Enhanced Data rates for Global Evolution (Edge) technology in the interim.

Edge can use the GSM/GPRS cellular networks already in place, and could also be used to fill in future gaps in 3G coverage.

Although no operators have yet committed to providing Edge services in the UK, last month saw AT&T Wireless launch a service in the US.

It offers average data rates of 100Kbps to 130Kbps, according to the company, and is expected to prove popular among roaming business users armed with notebook PCs.

AT&T will also offer Edge phones, including Nokia's 3200 models and Motorola's upcoming T725.

There are various tariff plans for the new service, including an unlimited call plan that will allow subscribers to transmit as much data as they like for about £50 per month.