900 Mhz Performance Field TestBy John Honovich, Published on Sep 07, 2009
Recently, Supercircuits performed a test of Firetide's 900 Mhz radios [link no longer available] in their warehouse. Their test results demonstrate the divergence between specifications and achievable rates in numerous conditions.
Keith Becker at SC Black [link no longer available] states that he:
"Conducted [his] own non line of sight test using Firetide 6000-900 nodes in a point to point set up for a SWAT team application. I set the nodes up going through 2 dry walls in our warehouse with metal racks and inventory and a fire safety wall on the other side of the warehouse. Just using the 5 dB omni staging antennas, I was able to get -95 dBm and maintain a connection of about 2 Mbps video throughput. Not great, but these were extreme non line of sight conditions and I was using very low gain omni antennas for the test. This was adequate for this project though as I was only sending 1 camera stream that maxed at 700 Kbps."
This 2mbps throughput is at the very low end of the range Firetide cited previously. Certainly, it is the walls and racks that significantly reduced the overall throughput. However, trying to shoot wireless through walls is a frequent request so even though the lower frequency of 900Mhz provides greater ability to penetrate walls, this field test demonstrates its limitations.
Updated 9/14: Firetide notes that the integrator used staging antennas. With higher gain antennas, such as the recommended circular polarized antennas, Firetide estimates that throughout could be significantly higher (upwards of 5 Mb/s).