Long distance is tempting, but it isn't necessarily a good idea. All kinds of wireless interference/collision will make available bandwidth really low.
For example, on 2.4 GHz 802.11 protocols, there are 11 channels from 1 to 11. All wireless routers operating in US have to be on one of the 11 channels. When there are other wireless APs within the range, you and others share the channel. There's a limitation on how much bandwidth a channel can give in total. That's the hard limitation, given that CSMA/CA works well. That's why channel 3 and channel 8 often work great (most wireless routers have default channel choice 1, 6, or 11) - they are far away from defaults that others are using.
Same thing applies to 5 GHz 802.11 networks.
Now back to this project. 1 km is really long distance. You get communication range as large as a circle with radius being 1 km. There are a lot of wireless devices that fall in this range. You might not get affected by them since they don't have that powerful antennas, but your signals will effectively lower the bandwidth of all routers in the area.
For example, on 2.4 GHz 802.11 protocols, there are 11 channels from 1 to 11. All wireless routers operating in US have to be on one of the 11 channels. When there are other wireless APs within the range, you and others share the channel. There's a limitation on how much bandwidth a channel can give in total. That's the hard limitation, given that CSMA/CA works well. That's why channel 3 and channel 8 often work great (most wireless routers have default channel choice 1, 6, or 11) - they are far away from defaults that others are using.
Same thing applies to 5 GHz 802.11 networks.
Now back to this project. 1 km is really long distance. You get communication range as large as a circle with radius being 1 km. There are a lot of wireless devices that fall in this range. You might not get affected by them since they don't have that powerful antennas, but your signals will effectively lower the bandwidth of all routers in the area.