A report released by Ofcom, the U.K.'s independent regulator and competition authority for the communications industries, has found that broadband speed needs improvement to keep up with the growing volume of large-scale Internet downloading and streaming from consumers.

The research was conducted over six months, from Nov. 2008 to April 2009, and included over 60 million separate service performance tests and a consumer perceptions survey from more than 1,600 homes.

For the month of April, the average broadband speed was 4.1 megabits per second (Mbit/s). In comparison, the average 'up to' headline speed offered to consumers was 7.1Mbit/s. Actual speeds varied widely, however 9% of the sample on 8Mbit/s headline packages had average speeds of over 6Mbit/s and 19% had less than 2Mbits.

Urban areas had "significantly" faster speeds, in comparison with rural areas, with comparative average speeds of 4.6Mbit/s against 3.3Mbit/s. The peak period of 8pm to 10pm saw speeds slow around 20% over a 24-hour period.

While the fact that second-generation DSL technology (ADSL2+) delivers faster Internet than the more common first-generation DSL technology (ADSL1) comes as no surprise, the report also found Internet Service Providers (ISPs) with a network capacity can deliver speeds equal to ADSL2+ operators.

The report surveyed nine of the U.K.'s largest ISPs, of which Tiscali had the lowest average speed at 3.2 to 3.7Mbit/s and O2 had the fastest at 4.1 to 5.1Mbit/s. O2 and Plusnet, however, had smaller sample sizes.

The survey found that broadband speed was still a key issue and that 26% of consumers believed their Internet speed was not what they had expected when signing up.

The research was carried out in conjunction with technical partner SamKnows and market research agency GfK.

The Internet Service Providers Association (ISPA) has responded to the report optimistically, however it highlights the inclusion of what it claims to be just six of the largest consumer ISPs. This, it believes, does not truly reflect the breadth of the ISP industry.

"ISPA supports greater transparency within the Internet industry, to which this report on broadband speeds contributes," said ISPA secretary general, Nicholas Lansman, in a statement. "ISPA members have worked closely with Ofcom to support this process and enable Ofcom to compile this report.

"Whilst the research does serve to provide information for people wishing to choose a provider, ISPA urges any future research to ensure that a greater share of the market is covered to provide a more complete assessment for consumers."

The trade body recognizes the issues raised in the report and intends to work with stakeholders, including Ofcom, to address them. It also urges consumers to be aware of the Ofcom Code of Practice on broadband speeds.