Feb 7, 2023
Long range wide area network (LoRaWAN) – Understanding Network and Security for Far-Edge Computing
Long range wide area network (LoRaWAN)
This is a protocol that sits on top of LoRA. It operates at Layer 2 (data link) and Layer 3 (network) of the OSI model. LoRaWAN does the same job that Ethernet and IP do for typical computer networks. It is possible to use LoRaWAN on top of a different Layer 1 radio technology, but this is uncommon.
Figure 3.34 – Examples of LoRaWAN gateways
LoRaWAN is an open standard that is supported by the LoRa Alliance, a non-profit organization that promotes the adoption of the technology. It is widely used, having been adopted by many major telcos around the world. LoRaWAN networks are used for applications that require long-range communication, low power consumption, and a low data rate, such as smart metering, asset tracking, and environmental monitoring.
The technology is well suited for non-video IoT applications because it allows rapid deployment of inexpensive sensors and relatively little infrastructure compared, to, say, 5G:
Figure 3.35 – Smart agriculture with LoRaWAN
A LoRaWAN network consists of the following elements:
End devices: These are also called nodes. They are the actual sensors, actuators, cameras, and the like in an IoT deployment. They communicate with gateways over the LoRa protocol.
Gateways: These are also called concentrators. These are similar to Wi-Fi extenders in that they act as a bridge from the end device/node to the network. Unlike Wi-Fi, however, a given device can talk to multiple gateways at once, and all a gateway does is gather those device messages and forward them to the network server. It is up to the network server to handle duplicate messages.
You usually want your devices to talk to a minimum of three gateways.
They also have an IP connection of some sort – it could be wired or wireless – so that they can communicate with the network server. That link is not LoRaWAN, because it is an aggregation point and needs higher throughput.
Network server: These could be thought of as similar to the AP controllers some enterprise Wi-Fi networks use to manage multiple access points. They receive messages from the gateways/concentrators and forward them to the application – both over an IP network.
They are also responsible for deduplication of messages. This is because multiple gateways can receive the same message from a given device, and they will simply forward them along and let the network server figure out if it is unique or not.
Note that LoRaWAN devices are not paired to a gateway – they are paired to a network server. The gateways are just a transport mechanism.
Application server: This is the final stop of a LoRaWAN message’s journey. The application server handles message encryption, data storage, and authentication of new nodes into the network.
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