I am fascinated by LoRa, but I understand it is primarily for low bandwidth applications that are optimized for high range, low power consumption. I'd imagine LoRA would be a good alternative to SMS but would it ever be an alternative for voice or higher bandwidth applications while still maintaining long range and low power?
No radio transmission that is above 30 MHz or so is really "high range". The modulation doesn't matter. The only thing that matters for range in non-ionospheric bouncing radio transmissions is the height above surrounding terrain of both ends of the link.
SMS works because the cell phone companies pay the big bucks to their base stations up very high above surrounding terrain.
There are transient exceptions like atmospheric gradients in water vapor density creating brief tropospheric ducts which VHF radio can bounce down but these are unreliable. And tropospheric scattering propagation requires very high powers and high gain antennas at both ends so it's not really feasible for people operating under FCC part 15 or even ham radio power restrictions (ie, <1500 watts).
LoRa is not a panacea, and of course any technology is best to what it is intended. With its ultra low power and data constraints LoRa is not aimed at high-bandwidth applications.
The perfect application is IoT, where a lot of use cases like telemetry, agriculture, etc. require only small data packets transmitted with longer (tens of minutes / hours) intervals.
Nope, it's not meant for that. Think low-bandwidth, small transmissions with highly compact but valuable data (sensors, actuators, etc). Even with LoRa as-is, changing settings to optimize for bandwidth costs you real range.
Exactly. Not LoRa but an example of what these modules and low bandwidth can do.
Many years ago (pre-LoRa) I needed to integrate a garage door that was far out of Wifi range to my home automation system.
At the time the way to go about this was (as best as I could tell) XBee. I was able to conjure together a 900 MHz XBee module in the garage that not only had (essentially) GPIO to activate a momentary relay to simulate a button push to control the door but also utilize an XBee feature called change detection that has an eventing/push system to transmit state changes from high to low on a pin. Combined with a magnetic door contact sensor and XBee + ESP 8266 + Arduino (platform for ESP 8266, not device) + MQTT on the Home Assistant side this thing has been running rock solid for a decade. I haven't had to work on it since.
Whether I check the status of the door (via Home Assistant or the OLED display on the control unit inside) or open/close the door via the momentary switch inside (or Home Assistant) even though it's been 10 years at least once I week I remark at how amazing the entire contraption is.
This stuff is really cool and maybe it's time to move this thing to LoRa!
Probably not worth it, Zigbee is literally designed for use case like that, LoRa is designed for use cases where you'd have much wider geographical spread of sensors.
But something like solar powered sensor somewhere farther away would be a good use case.
Speaking of costs, are the public gateways actually free to use or does one need something like a sim card to use them? What prevents people from spamming messages at rates that completely clog the network?
If we are talking about the radio spectrum: Not much - other than the threat of the regulators showing up at your doorsteps after they found you with a van. If you are talking about the backbone so to say, it's not such a big Issue. The original packet-forwarder sends "json" over UDP. If you are using a packet-forwarder by one of the network operators, some of them are using MQTT (IP/TCP) as the transport.
Some gateways let you filter by network_id, this will not stop someone from pulliting/disrupting the radio spectrum, but it will stop your gateway from relaying those packets to your network-server.
If everyone having a phone in their pocket at all times has taught me anything, it's that people hate talking to each other over the phone... :-). LoRA/Meshtastic seems like a really interesting SMS transit.
