Mobile telecoms regulator Ofcom released its first study of 3G mobile broadband at the end of last week, citing O2 as the provider of the fastest service with an average speed of around 2.7MBit/s.

The study involved some 4.2 million hourly tests using ‘static probes’ across the mobile phone network at 97 locations. Ofcom then complemented this testing with results, taken four times a day, from 1,00 actual users to gain a more realistic picture of 3G performance.

The static probe testing gave an average download speed of 2.1Mbit/s, which equates to a 20-second download for a 5MB MP3 or 17 minutes for a typical 30-minute (250MB) TV programme. The average time to download a web page from a range of popular UK web sites was 2.2 seconds.

Results from the user tests, however, painted a somewhat different picture, with the average download speed being just 1.5Mbit/s and average web page download times of 8.5 seconds.

The reception to the 3G mobile broadband testing has been pretty mixed, with some critics citing average download speeds of under 2Mbit/s as evidence for operators failing to sufficiently invest in their networks.

It also looks like Ofcom’s approach to testing may have skewed the results, too — it conducted its static tests at handpicked locations known to offer the best 3G download speeds, which explains why they’re so much higher than the user testing.

Sillier still, its web page download speed tests didn’t include any embedded images or video. This decision was purportedly made for the sake of consistency across the networks, but it also creates an unrealistic test environment and few home broadband internet connections can download a complete web page in less than the 2.2 seconds Ofcom cites for mobile broadband.

So, if you’ve seen the news coverage of the Ofcom report and are thinking about switching 3G mobile broadband providers purely to take advantage of what look like blisteringly fast download speeds compared to what you get now, think again.