LoRa Hybrid Mode and FCC regulations

As indicated in my previous post, LoRa implementation in North America presents itself with several challenges imposed by FCC regulations. However, hybrid mode deployed by Multitech and Kerlink and probably also by Link Labs provide clever solution to this problem:
As per Semtech: There is an FCC OET publication [5] that details a possible hybrid mode scenario:

It is possible for a device to be designed to operate as a DTS, as a FHSS system, or using a combination of these two modulation types.
A hybrid system uses both digital modulation and frequency hopping techniques at the same time on the same carrier. As shown in Section 15.247(f), a hybrid system must comply with the power density standard of 8 dBm in any 3 kHz band when the frequency hopping function is turned off. The transmission also must comply with a 0.4 second / channel maximum dwell time when the hopping function is turned on. There is no requirement for this type of hybrid system to comply with the 500 kHz minimum bandwidth normally associated with a DTS transmission; and, there is no minimum number of hopping channels associated with this type of hybrid system.
As a possible application scenario, consider a system operating with eight 200 kHz channels.
To comply with the requirements for hybrid operation the channel dwell time in frequency hopping mode must not exceed 400 ms in any (400 ms * 8 channels) 3.2 seconds. In addition, the power spectral density shall not exceed +8 dBm in any 3 kHz bandwidth.

It is a good alternative and perhaps, soon we will see plenty of choices for LoRa gateways operating within North American spectrum. The power needs to be limited and capacity is also limited, but still it is an inexpensive way to deploy LoRa network in North America.

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