(slightly) offtopic- radio modems

[Nikolay Elkov <nickx@example.com>]

I will need a radio modem which works with Linux. I know next to nothing about wireless communication and I am using the term 'radio modem' simply because I don`t know a better word. I need something which works at a distance  500-1000 m. I want to connect two machines only, so some kind of a poin-to-point solution is needed. I have looked at what they have in stores- it seems they only offer 'wireless lan' devices which have a range of about 50-100 m. Haven`t had the time to check out Akihabara though. Can a 'radio modem' be bought in Japan, does anyone know how much it will costs? Any useful links are welcome. Thanks in advance.