CODEWITHSUNDEEP
network-programmingembeddedlorawanmesh-network
Jordan
Jordan

Reputation: 4512

Long Range Mesh for Embedded Devices

I have a project where I need to deploy a cluster of 20 embedded devices. Each device has an embedded microcontrollerr (nRF52840) with a 64MHz Cortex M4 processor. The devices will be spaced 100 - 200m apart.

5 of these devices will have embedded satellite terminals (Iridium Edge), which are controlled by the nRF52840. I need the other 15 devices to use the 5 satellite-enabled devices as gateways. However, these satellite gateways do not use IP protocol, it's a custom low-power low-data-rate protocol.

So, essentially, I need each non-gateway device to have knowledge of which gateway is closest, send that gateway a message, and then have the gateway detect that this message is for re-transmission over the satellite terminal.

LoRa seems like a good fit for this because it has sufficient range and I have low data rate requirements. However, I'm not sure that this is feasible due to the requirement to have a single network server, which would be a single point of failure and the 64MHz Cortex M4 may not be powerful enough to actually run a network server. I can't seem to find any network server software that is designed for low-power embedded devices.

So, my questions are:

  1. Is there a more suitable technology than LoRa which has a range of at least 300m?
  2. If not, does LoRaWAN support a high-availability design that does not have a single point of failure (the device running the network server)?
  3. Is there network server software available that would operate on a low-power embedded device (using Zephyr)?

Upvotes: 0

Views: 66

Answers (1)

Stefan
Stefan

Reputation: 1056

I assume you know the difference between LoRa and LoRaWAN, as your questions suggest.

ad 1: Maybe, don't know. LoRa has more than enough range, depending on environment/orography: urban at least 500 m, rural several km, with free view hundreds of km.

ad 2: LoRaWAN supports having an arbitrary number of gateways. All GWs that receive an uplink message that is broadcast by a node will forward it (via IP) to the server. Downlink messages are routed via the "best" gateway.

But LoRaWAN is not (directly) suited for your application. You could instead use another system based on LoRa radio. Maybe Meshtastic or DASH7.

Keep in mind that any device that has to constantly listen on a radio channel (or even several channels simultaneously) needs power for that. This is the reason LoRaWAN has different types of devices (class A, B, and C nodes; gateways).

ad 3: Don't know.

Upvotes: 0

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