If you watch freeview, you need to read this.

What's happening and why?

New 4g mobile services are coming to your area soon.
They operate at 800MHz, a similar frequency to Freeview, and so may cause problems to your Freeview service such as loss of sound, blocky images or loss of TV channels.

To overcome this problem, you will soon receive -Free Of Charge- an at800 filter. it is straightforward to fit and connects between your TV aerial and your television , set top box or signal booster.

(Only one free of charge at800 filter per household.

www.at800.tv
Call 0333 31 31 800

Interesting article here:

http://www.theregister.co.uk/2013/06/07/4g_will_only_leave_90000_without_telly/

at800 are mailing selected addresses in the area prior to activation of masts with 800 MHz 4g (aka LTE800).
Will 4g masts affect freeview in my area?

Trials so far have proved that 4G interference at 800 MHz will be much lower than predicted and very much in line with the levels of interference experienced in Sweden and Germany which was minimal.
at800 updates estimate of likely impact of 4G at 800 MHz on Freeview

I have just received my at800 filter today.