Hi Dilip! 

Could you please provide a bit more context on the project you're hoping to carry out? That will give folks a better idea of how to help! 

All the best,

Carly

I've got quite a lot of experience with wireless in forested areas and over long(ish) ranges.

Using a wifi mesh is totally possible, and it will work.  You will likely not get great range between units.  You will likely need to have your mesh be fairly adaptable as conditions change.

Wireless and forests interact in somewhat unpredictable ways it turns out.  Generally, wireless is attenuated by water in the line-of-sight between stations.  From the Wifi perspective, a tree is just a lot of water up in the air.  Denser forest = more water = worse communications. LoRa @ 900Mhz is less prone to this issue than Wifi @ 2.4Ghz and way less prone than Wifi @ 5Ghz.  But LoRa is also fairly low data rate.  Streaming video via LoRa is possible with a lot of work, but video streaming is not at all what LoRa was build to do, and it does it quite poorly at best.

The real issue I see here is to do with power levels.  CCTV, audio streaming, etc are high data rate activities.  You may need quite a lot of power to run these systems effectively both for the initial data collection and then for the communications.

If you are planning to run mains power to each of these units, you may be better off running an ethernet cable as well.  Alternatively, you can run "power line" networking, which has remarkably good bandwidth and gets you back down to a single twisted pair for power and communications.

If you are planning to run off batteries and/or solar, you may need a somewhat large power system to support your application?

I would recommend going with Ubiquity 2.4Ghz devices which have performed relatively well in dense foliage of the California Redwood forests. It took a lot of tweaking to find paths through the dense tree cover as mentioned in the previous posts.