Hello, while traditional Wi-Fi mesh would be able to connect these buildings together (Root/Non-Root bridges), a PMP (Point to MultiPoint) setup would offer much more robust connections and functionality (e.g. dedicating unequal bandwidth to each endpoint (SM - subscriber module)). Good options for you are the PMP450i series or ePMP3000 series. If there is a small number of end points, you may consider dedicated PTP (Point to Point) links, as you can offer much more bandwidth than a PMP setup. If you go PTP, there are much more options, with data ranges from Mbps to Gbps. I would recommend reaching out to your local Cambium Networks Account team for help determining the best options.
The nomenclature that we use for a fixed wireless PMP setup is AP (Access Point, comparable to a root bridge in WiFi) and SM (Subscriber Module, comparable to a non-root bridge in WiFi). As Dave points out, the models for an AP and SM are the same (PMP450i), but there are separate part numbers for AP's versus SM's, and an AP cannot become an SM and vice versa.
Lots of good information here:
https://www.youtube.com/user/CambiumNetworksLtd
http://community.cambiumnetworks.com/t5/Welcome-Board/Webinar-Archive/m-p/46088#M77
http://community.cambiumnetworks.com/t5/Connecting-U/Cambium-College/m-p/69663#U69663