I have a problem with my Huewei P8 lites wifi connection.

[AC Question]

The wifi connects perfectly fine when im right by the router, as soon as i walk away from the router it disconnects and says "denied access to network" and if i try and forget network and retype my password it says connecting and then says "saved,secured". So i cant access any wifi on my phone unless i stand right by the router. Please help me with this problem