On 12/28/2010 11:48 PM, Anonymous List User wrote:
For architectural and building management reasons we cannot mount our antennas in a rooftop or outdoor location at either end. The distance between two buildings is 1.5 km, and the fresnel zone is clear. Antennas need to be located indoors at both ends and will be placed on small speaker stand tripod pointing at windows. This has been done successfully before with 2.4 GHz 802.11g equipment and a link from an office in the Westin to a nearby apartment building, but I am unsure of what effect glass will have on 5 GHz. Has anyone tried this?
Low-E glass is brutal on radio waves. If the windows are tinted, multi-layer, or have metalic particles success may be difficult. You may want to test with some 802.11a network cards in ad-hoc mode to see if you can actually communicate over the 1500m path. We have had to deal with a condo association to get approval to mount some panels outside at one site. It can usually be discussed when presented with the facts and some photo-shop edits to show what visual impact it will have. However, be prepared for a significant delay in some cases and success is never a sure thing. Another item of concern is you are looking at IC/FCC unlicensed bands. Ten years ago 5.8 was fairly clean, but more recently we have found a lot more consumer devices invading the spectrum. We had a 1km path with a $15K microwave system knocked out by a consumer $50 cordless phone that was 1/2 block away. (We purchased a DECT6 phone for them and 'solved' the immediate issue... until we could obtain a license/path and the equipment to install something that wouldn't be interfered with.) -- Shane Allan Godmere Senior Telecommunications Engineer II Michigan Technological University 1400 Townsend Dr. EERC-B31 Houghton, MI 49931