How to improve the signal strength of wi-tribe CPE?

i was receiving 4 signal bars when i got wi-tribe at my home in johar town earlier this year. the signal strength has dropped to 1 bar recently, with 2 bars occasionally. however, the browsing experience is almost the same. is there any way to get better signals in the same location? the wi-tribe tower is less than 1 km away, i suppose.

any one? i want the ans too?

do you need external thing like wateen?