5GHz Regulations in Canada (2018 Update)

DFS (Dynamic Frequency Selection) is a mechanism that allows wireless LANs to coexist with radar systems. It automatically selects a frequency that does not interfere with the radar systems. In Canada, any Wi-Fi devices operating on the channels 52-64, 100-116 and 132-140  have to employ a DFS radar detection mechanism. The use of DFS while implementing a Wi-Fi network is the choice of the Engineer. It allows you to use more channels for sure, however, the frequency change might bring some instability in the network. Moreover, the client devices are not always certified for DFS band operation which is the case for many portable devices. Therefore, many engineers prefer implementing their network without the use of these “DFS” channels.

Concerning the UNII3 & ISM bands (5725-5850MHz), the conducted output power shall not exceed 1W. If directional antennas are used with a gain greater than 6dBi, the maximum conducted output power shall be reduced by the amount in dB that the directional gain of the antenna exceeds 6dBi. So basically the maximum e.i.r.p. will never exceed 4W and if the gain of the antenna is greater than 6dBi, the output power will be adjusted accordingly.
However, the standards stats that “fixed point-to-point devices operating in this band may employ transmitting antennas with directional gain greater than 6dBi without any corresponding reduction in transmitter conducted power“.

So, on the left part of the drawing, we are using an antenna gain of 9dBi; which is 3dBi greater than 6dBi. If we were to use the maximum conducted power possible (i.e. 1W), the total e.i.r.p. would be: 30dBm (1W) + 9dBi = 39dBm (8W). 8W is over the maximum allowed (4W). So in order to stay under the regulations, we need to lower the conducted power by the number of the antenna gain dB greater than 6 (in our case 9-6 = 3dB). So the new conducted power would be: 30dBm (1W) – 3dB = 27dBm (500mW).
If we use a conducted power of 500mW we will have the following e.i.r.p.: 27dBm (500mW) + 9dBi = 36dBm (4W). This complies with the regulations!

ISED received comments proposing that some portions of the band become available for license-exempt devices (eg. Wi-Fi). However, they did not propose any specific changes to this band in 2018 pending potential outcomes of the WRC-19 (World Radio Conference).  There will most likely be some changes in the next few years. Since ISED is involved in the WRC-19 conference that will be taking place in Oct/Nov 2019, we could be expecting some changes as early as late 2019. Here are the potential changes:

• Use of the 5600-5650 MHz Band for license-exempt use. Channel 120, 124, 128
• Use of the 5350-5470 MHz Band for license-exempt use. Channel 68, 72, 76, 80, 84, 88, 92, 96
• Use of the 5850-5925 MHz Band for license-exempt use. Channel 169, 173, 171. This is unlikely as ISED prefers to reserve this band for connected vehicle applications. They will only allow Wi-Fi to share this band if they know for sure that it won’t be disruptive.

I hope this information will be useful for some of you.

If you are deploying Wi-Fi on the 5GHz band in Canada, I would invite you to take a look at the following documents:

• Document from ISED – Specifications:​ RSS-247 — Digital Transmission Systems (DTSs), Frequency Hopping Systems (FHSs) and Licence-Exempt Local Area Network (LE-LAN) Devices – Spectrum management and telecommunications
• Document from ISED – Apply for the license: Decision on the Technical and Policy Framework for Radio Local Area Network Devices Operating in the 5150-5250 MHz Frequency Band – Spectrum management and telecommunications
• ISED Spectrum Outlook 2018 to 2022: https://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf11403.html
• Chart  – Radio Spectrum Allocations in Canada: https://www.ic.gc.ca/eic/site/smt-gst.nsf/vwapj/2018_Canadian_Radio_Spectrum_Chart.PDF/$FILE/2018_Canadian_Radio_Spectrum_Chart.PDF