I’ve been working on the English Wikipedia article on LoRa. LoRa uses a spread-spectrum technology. It’s another one, not FH or DSS. It’s called Chirp Spread Spectrum (CSS).
LoRa has ISO layers like many Internet Protocols. It has a PHY layer and upper layers.
The LoRa standard is proprietary and describes the PHY layer. It’s implemented by the LoRa chip used in Outernet. A few hackers seem to have reverse engineered it.
The upper layers are described by LoRaWAN. These layers are specified in an open standard. However,
Outernet replaces the upper layer protocols with its own receive-only protocol.
LoRa, IMHO, has several very good features:
- It has Process Gain. This in short enables LoRa to hear below the noise level. This is why Outernet works when we have SNRs below zero.
- It has a really high PAPR, meaning it does not require highly linear amplifiers and thus amplifiers are relatively easy to build for it.
- It has the ability to cover very large distances due to 1) and 2)
- It’s immune to Doppler. This is not an issue with GeoStationary satellites. But, there’s plenty of things that might involve LEO satellites.
LoRaWAN is being implemented world-wide. It’s shortcoming is that it’s being deployed in very crowded unlicensed ISM bands. Wouldn’t it be nice if it could be deployed in a ham band where the near line of sight properties can be fully utilized?