1. Outdoor wireless bridges can be used to connect building LANs to each other. For example, check out Cisco's Aironet 1300 Series Outdoor Access Point/Bridge and 1400 Series Wireless Bridge and Zyzel's ZyAIR B-3000 Secure Wireless Bridge/Repeater. When using an outdoor bridge, you will probably mount an external antenna on each building's roof or next to a window.
2. To interconnect the PCs (and server) inside each building with wireless, you can use indoor wireless Access Points. Wireless APs are readily available from dozens of vendors, including D-Link, Cisco Linksys, and Netgear. If you have just 10 PCs per building in relatively close proximity, a single AP per building may do the trick, depending on the throughput required by each PC.
Note that you don't need to use wireless technology in both places. You could run wires between buildings and use wireless indoors, or you could cable your PCs to a hub or switch and use wireless only for outdoor bridging. If you decide to use wireless for both, be sure to select channels that avoid interference.
This was first published in September 2004