I've been playing with a Motorola Canopy wireless broadband system and I'm going to share some of the info I've found.
5.8Ghz is very picky about how far it will will go. It can pass through things like glass, wood and plaster but has problems with metal and trees. The pictures below are from my initial experiments. My AP (Access Point) is sitting at work pointed out a 11th story window in the direction of my house. I have three SU (Subscriber Units). One is at my house (the red arrow), one it on a ten foot pole at a friends place (green arrow).
The office building has a film over the window. I had assumed it was clear for 5.8 Ghz because GPS signals at 1.3 Ghz weren't affected by the glass but it may have enough tint to be a real problem for the high speed Canopy system. It appears that the glass causes about 4db loss however the major problem is the metal foil cuases multipath which upsets canopy.
The red arrow shows where the access point is. This photo was taken from about
300 meters (yards) away. Click on the photo for a larger version.
This is a picture from the AP of two of the SU locations. The red
arrow shows where my house is (600m) and while the green arrow on
the right shows where a SU is on a friends roof at a distance of
about 1.1km. The red location has never gotten a lock and the RSSI of
the green location is about 550 when it can get a lock. The antenna
at the green location isn't pointed quite properly and I hope to re-rig it
You can tell the that there is quite a bit of tree coverage in the Fresnel Zone to the red site.
This is where I first placed the AP for testing. Its not very high and there are trees in every direction. With the AP at this location, I was getting strong
signals at least 500m away which was as far as I could get reasonable line
of sight coverage without large buildings getting in the way.
This is the current AP location. I would love to get it outside but I
can't open the windows.
|Back to Tim's Homepage||Back to current subject||Related Linksfirstname.lastname@example.org|
|This page was last updated Friday, 05-Sep-2003 13:42:53 UTC||Copyright 2000-2018||thogard is a trademark of Tim Hogard|