Mobile operator 3 has cut its mobile data rates for laptop users, so subscribers can get so-called 3.5G speeds of up to 2.8 Mbit/s for as little as £10 a month.

The service will be available from 4 September on 3's network and the operator plans to provide HSDPA to 85 percent of the UK by December. The £10 "Light" service gives 1GB of data over the month, while users paying £15 or £25 get 3GB or 7GB respectively. Beyond these limits, 3 will charge 10p per Mbyte.

The deal gives a better price-per-megabyte than current offerings from T-Mobile, Vodafone, O2 and Orange, but further cuts are surely on the way, as operators compete to get more customers using wireless broadband.

Operators and analysts expect HSDPA to be the catalyst that finally gets 3G to take off, for both mobile handsets and laptops. There should be a billion users on mobile broadband by 2012, according to Juniper Research - the vast majority of which will be on mobile phones, of which about a third will be HDSPA capable, according to Juniper. The HSPA family, which starts with HSDPA and HSUPA for faster download and upload, will make up 70 percent of the mobile wireless broadband market, Juniper predicts.

"Mobile broadband will be a device-based technology," said Howard Wilcox of Juniper. "The main gating issue that will dictate takeup will be the availability of suitable devices, whether handsets, laptops, datacards, or other types of device such as media players." HSPA is a software upgrade for operators with 3G networks, and many have plans to roll it out - with Vodafone Vodafone launching first in the UK, last June, followed by T-Mobile, O2 3 and Orange launching later that year.

By comparison, Wilcox reckons that Mobile WiMax will have less than ten percent of the wireless broadband market in 2012 - but says this is impressive from a standing start: "This will represent a significant attainment for this new mobile platform. We believe that the WiMAX market will see substantial growth after 2012, as new networks are built out and new applications are adopted."

To use the service, users have a USB 3G modem, for a price varying from £80 to free, depending on the length of their contract.