Maximum EIRP for Ubiquiti Products in Australia

Ubiquiti™ products operate over a wide range of powers, frequencies/channels, and channel spectral width. This page summarises and documents how this applies in Australia, and explains some new terms.

Channel Spectral Width

Reducing spectral width provides benefits and drawbacks.

Benefits:

1. It will increase the amount of non-overlapping channels. This can allow networks to scale better.
2. It will increase the Power Spectral Density (PSD) of the channel and enable the link distance to be increased.

Drawbacks:

1. It will reduce throughput proportional to the channel size reduction. So just as turbo mode (40MHz) increases possible speeds by 2x, half spectrum channel (10MHz), will decrease possible speeds by 2x.
2. In Australia, some channels have maximum permitted PSD limits. In some (but not all) cases, using a smaller channel width also means you will have to drop the transmit power - negating Benefit 2.

Dynamic Frequency Selection (DFS) and Transmitter Power Control (TPC)

Some 5 GHz WiFi channels co-exist with some Radar frequencies. Rather than ban WiFi for these frequencies, the ACMA has followed the same principle used in USA and the EU and allowed WiFi to operate on these same frequencies under the limitation that the WiFi gear must have:

• DFS: a mechanism to automatically detect Radar, and move off to a different channel,  and
• TPC: a mechanism where the TX power can be reduced at least 6 dB below the maximum permitted.

For more information see ETSI EN 301 893, and FCC Section 15.407 which are the EU and USA standards to which Ubiquiti 5GHz equipment conform. What this means is that while you may set the equipment to operate at a specific channel, it may automatically migrate to a different channel at some time in the future. To avoid this use the chart below to choose channel/power/width settings that do not require DFC, and then disable DFS in the Advanced Wireless Settings.

mW to dBm Converter

Reference: Radiocommunications (Low Interference Potential Devices) Class Licence 2000 as amended document as published 1-July-2009 by the Australian government.