Narendra Singh
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Hi Jason,
Thanks for your suggestions. It helped in carrying out the tests. But it failed to complete the FCC tests. Here i have attached extract from FCC standard document available at https://www.ecfr.gov/cgi-bin/text-idx?SID=21f32428b015d0b23b71f331ec5d4f64&mc=true&node=se47.1.15_1247&rgn=div8
“(i) For frequency hopping systems operating in the 902-928 MHz band: if the 20 dB bandwidth of the hopping channel is less than 250 kHz, the system shall use at least 50 hopping frequencies and the average time of occupancy on any frequency shall not be greater than 0.4 seconds within a 20 second period; if the 20 dB bandwidth of the hopping channel is 250 kHz or greater, the system shall use at least 25 hopping frequencies and the average time of occupancy on any frequency shall not be greater than 0.4 seconds within a 10 second period. The maximum allowed 20 dB bandwidth of the hopping channel is 500 kHz.”
As per this standard, it needs to hop for minimum 25 frequencies but this module hops just for 8 frequencies.
Another issue i faced is in signal strength. The signal level emitted by the module was much beyond the standard limit. As per information from FCC Lab, maximum signal strength should be 94dBuV but we were getting 107dBuV for transmit power set to 11(AT+TXP=11″) For higher power setting > 11, the strength level was increasing for each increasing power setting and strength was much higher which was around 116dBuV for AT+TXP=19.Can you please suggest any solution to this issue? Since the module is FCC certified so we expected it to pass through FCC tests easily but it failed to pass in Radiated Emission tests,Field Strength tests.We are not able to proceed for further tests as the module is failing in these tests.
