This time last week I was over in Bournemouth lab as Brighton is being refitted ready to open fresh in the new year. I had the chance to sit in on an IOT session being run by Doug from Things Connected, an initiative run by Digital Catapult, Doug had arrived at 1 pm and we got speaking before the rest of the people turned up. He has been working on the Sigfox network on the south coast for the last year and has made a great little low energy board powered by an ESP32.
Now if you have read my other blog on the ESP8266 you will know the 32 is part of the same family a chip with built-in WiFi and the 32 comes with added support for Bluetooth and to add on one of the long-range modems Like SigFox or Lora.
The Board was great and you can see it below Doug has these etched in China and he populates them here in the UK with the chips needed. You can check out everything on the NetSensors Github here.
What I wanted to explain today was the a bit about the Networks for IOT and the main two in the Maker / MVP arena, at the moment it’s a battle to which one is going to win out, think VHS and BetaMax. Both came out of France! Both have star topology. Both use unlicensed ISM band.
- Sigfox uses Ultra narrowband & this means a higher spectral efficiency and can mitigate the noise better.
- Sigfox uses DBPSK (Differential BPSK) for uplink & GFSK for downlink.
- Sigfox is sharing their reference design with chip vendors, so everyone with Sigfox certification can sell the chips and get share of LPWAN "revolution".
- Sigfox has higher range and one BS can connect much more devices.
- Sigfox is very practical for infrequent transmissions and offers longer battery life.
- Sigfox is almost free (costs 1 Euro per device per year).
- Sigfox is good to prevent replay and man-in-the-middle attacks. Uses AES encryption with HMACs with private key that's embedded in the device + some sequence number. Though, this's not a big deal as 12 bytes of small packets cannot carry critical data (e.g. credit card info, pwd etc.).
- LoRa uses Chirp spread spectrum.
- LoRa is owned by Semtech and thus, you have to use Semtech modules for your development
- LoRa is dominant in Europe and it's deployment is up the community. You can also buy your own base station for £200 and use it.
- LoRa allows you to use more bandwidth.
- Using LoRa is free.
- LoRa has weaker security compared to Sigfox.
So yeah massive Pros and Cons on both sides, both are trying to be the global IoT network and we'll see it in the future, but operators are leaning on NB-IoT & LTE-M, so we'll see who wins the IOT war in the future.