Can I have the Idea of wireless networking that can cover about 5-7 kilometer from my hom? I want to set up if possible a wifi (it may not be really wifi since wifi will not go beyound 300 meteres i guess ) but such that will just connect poeople with laptops 5-7km away from the router (or what you think it to be)an give a perfect signsl any additional hardwre after their networking card. Can you sugest those equipments that are involved and the way to connect them?

As far as I know there is no economical way to direct connect over anything like the distance you are talking about. For one thing, a radio transmitter powerful enough to operate over that distance would come under some kind of government regulation. You would also need two transmitters as LAN is a two way communications channel. You should be investigating VPN software to operate a secure connection via internet I used to have a signature but it disappeared and I just couldn't be bothered writing another so please feel free to ingore this.

You can do it right now. Most homeowners are limited by their countries laws regarding the signal amplitude. Find your laws and you will find a company that sells a product within the law that will suit your needs. There are also devices that may allow that much range too with modern directional antenna and hi-gain amps. A line of sight would be best. Many factors determine your local ability. As a side note there used to be a gizmo that used a laser to transmit data. Dunno if that is around anymore. I read it wrong and answer it wrong too. So get off my case you goober.