[bbc] A survey by comparison site Broadband Expert suggests that UK mobile broadband providers are delivering services "far lower than advertised".
Almost three and a half thousand broadband connections were tested over a five month period.
The firm found that users recorded an average download speed of 1.1Mbs, substantially lower than advertised.
However, some experts queried the results, saying that quantifying mobile broadband was almost impossible.
Rob Webber, Broadband Expert's commercial director, explained how they did the tests.
"These are tests performed by users on the Broadband Expert website. They select their internet service provider, their promised connection speed, and the sort of connection they have.
"As a result, some providers got tested more than others and we did not have enough data on British Telecom or Virgin Mobile to give a valid result," he said.
Mobile broadband speed 'too slow'