PS GPS

Th easiest way to extend the range of your wireless lan is to buy an access point that can be configured as a repeater. Linksys do some nice cheap ones.

It’s a very simple configuration in the access point setup page & will be documented in the manual ( check when you buy that it has this capability as lots don’t )

If the distance from your current access point is to far, you can buy directional aerials that will extend the range in a narrow band.

There is also the option of running a crossover cat5e cable between the 2 access points ( or router & access point ). this would still allow extension of the wireless network, but be hard wired between the 2 physical sites.