7 ms·
Great question. It depends on the technology. For example with LoRa, in the US there are 64 usable channels. In addition there are 5 available "spreading factor
by slewis 11y ago
Great question. It depends on the technology. For example with LoRa, in the US there are 64 usable channels. In addition there are 5 available "spreading factors" per channel that are orthogonal to each other. A lower spreading factor device may communicate at twice the data rate of the one above it (but with worse range). So for example one device may communicate at 1kbps at SF12, another may communicate at SF11 at 2kpbs at the same time. This means you can have 31 devices communicating 1kb within a 1 second window, on a single channel.
Other technologies can have many more simultaneously communicating devices. In the case of OnRamp/Ingenu, a factor of 1600 more due to their encoding scheme.
Narrowband technologies like SigFox (based on TI radios), have way more than 64 channels available in the US, I believe in the range of 1000, but are more susceptible to interference.
- nicolsc 11y agoSigfox doesn't have channels per se. Each Sigfox message is concentrated on ~100Hz, with the base stations listening to a 200KHz part of the available spectrum. Regarding interferors, the Ultra Narrow Band technology offers a great resistence: energy concentrated on a tiny width, plus the "random frequency" effect of the sigfox protocol.
- nicolsc 11y agoForgot to add that Sigfox isn't based on TI radios, but is hardware-agnostic. Basically, most sub-GHz radio transceivers are compatible, and it's all about adding the soft stack. Current HW partners include TI, SiLabs, Atmel, Axsem, .. We'll be using TI HW (Launchpad dev kit) on our SF event on Nov 20 (https://www.eventbrite.com/e/smart-city-iot-hackathon-connect-your-city-tickets-19092263474 https://www.eventbrite.com/e/smart-city-iot-hackathon-connec...), but we're fully open on the hardware side. Full list here : http://makers.sigfox.com/ http://makers.sigfox.com/