Use the internet in your home where you don't have a signal. This is for devices (computers and laptops) that have a LAN port/socket.
This kit (made by Devolo) puts the internet signal into your home electrical system. One plug converts the signal from your router into the electrical system and the other converts it back to be used by a computer. In both cases each uses a LAN cable as shown in the picture,
Homeplug Powerline kit (Staple Hill BS15)
This offer has been gifted to someone and is no longer available.