April 19, 2021
Guidance on Radio Standards Specification RSS-247
This notice provides guidance to ensure that the requirements listed in RSS-247 are properly assessed and reported, according to Innovation, Science and Economic Development Canada (ISED)’s technical standards.
1. Guidance related to RSS-247 section 5.2 - Digital transmission systems
The latest measurement procedures accepted by ISED shall be used. Previous versions of ANSI C63.10 or FCC KDB are not acceptable.
Power spectral density (PSD) measurement shall be performed by using the correct detector as it relates to the methodology of measuring output power. PSD and output power shall be performed using the same detector methods.
ISED has been observing that peak power measurement and maximum conducted output power are being used interchangeably in the reports. Either peak power measurement or maximum conducted output power shall be used consistently.
The equipment’s operating Occupied bandwidth shall be reported.
2. Guidance related to RSS-247 section 5.3 - Hybrid systems
Hybrid systems employ a combination of both frequency hopping and digital transmission techniques. The classification of devices as hybrid system shall be clearly stated in the technical brief submitted to ISED.
3. Guidance related to RSS-247 section 5.5 - Unwanted Emissions
In any 100 kHz bandwidth outside the frequency band in which the spread spectrum or digitally modulated device is operating, the RF power that is produced shall be at least 20 dB below that in the 100 kHz bandwidth within the band that contains the highest level of the desired power, based on either an RF conducted or a radiated measurement, provided that the transmitter demonstrates compliance with the peak conducted power limits. If the transmitter complies with the conducted power limits based on the use of root-mean-square averaging over a time interval, as permitted under section 5.4(d), the attenuation required shall be 30 dB instead of 20 dB. Attenuation below the general field strength limits specified in RSS-Gen is not required.
The reports provided to ISED shall include a detailed description of the test methodology used to demonstrate compliance in accordance with an acceptable normative test procedure; demonstrate that the device under test has been exercised in the correct operational states; demonstrate that the applicable attenuation (dBc) limit has been selected based on the methodology used for measuring output power; and demonstrate compliance with band edge requirements.
4. Guidance related to RSS-247 section - 18.104.22.168 Power limits
Reports submitted to ISED shall clearly demonstrate compliance with equivalent isotropically radiated power (e.i.r.p) limits established by ISED. Only providing conducted power measurement results is insufficient to demonstrate compliance with the requirements listed under the clause 22.214.171.124.
5. Guidance related to RSS-247 section - 126.96.36.199 Unwanted emission limits
For transmitters with operating frequencies in the band 5150-5250 MHz, all emissions outside the band 5150-5350 MHz shall not exceed -27 dBm/MHz e.i.r.p. Any unwanted emissions that fall into the band 5250-5350 MHz shall be attenuated below the channel power by at least 26 dB, when measured using a resolution bandwidth between 1 and 5% of the occupied bandwidth (i.e. 99% bandwidth), above 5250 MHz. The 26 dB bandwidth may fall into the 5250-5350 MHz band; however, if the occupied bandwidth also falls within the 5250-5350 MHz band, the transmission is considered as intentional and the devices shall comply with all requirements in the band 5250-5350 title="Megahertz">MHz including implementing dynamic frequency selection (DFS) and TPC, on the portion of the emission that resides in the 5250-5350 MHz band.
Reports submitted to ISED shall clearly demonstrate how devices operating in the 5150-5250 MHz band comply with the applicable attenuation limit at the 5250 MHz band-edge.