LEWISHAM, Greenwich and Southwark Freeview services could be disrupted next week when a 4G mobile service is trialled.
Company at800 is running the test on April 15, asking viewers to report problems to them.
The test will measure the extent to which 4G at 800Mhz will disrupt television services.
4G enables mobile devices such as smartphones, laptops and tablet PCs to access the internet at super-fast speeds.
Chief executive of at800 Simon Beresford-Wylie said: "These larger tests are essential to help improve our forecast model and the way we’ll tackle potential issues caused by 4G at 800 MHz.
"We are extremely grateful to viewers in south east London for their help with these important tests."
If you live in the south east London area and notice problems with your Freeview service call 0333 31 31 800.
You will be asked for your postcode, the type of interference and the time it occurred. This will allow at800 to restore your service as soon as possible.
If you have not been contacted directly through the post, any interference to your Freeview service is unlikely to be due to the 4G test. TVs connected to a cable or satellite service are not affected.
For more information, visit the website.