如何選擇合適的Lorawan課程 (一個, 乙, c): 一個簡單的指南

介紹

In IoT, 並非所有設備都在計時和交流時說相同的“語言”. 在 洛拉萬, 有三個定義的設備類 - 一個, 乙, 和C-每個都有自己的模式發送和接收數據. 知道差異很重要. 它會影響您的設備響應速度, 他們在電池上持續多長時間, 以及它們適合您的用例.

What are LoRa and LoRaWAN?

LoRa is the wireless modulation that carries data over long distances using low power. LoRaWAN is the network protocol that sits on top, defining how devices connect, send, and receive messages through gateways to a network server. LoRa is the physical layer. LoRaWAN is the rules of the conversation.

What are LoRaWAN Classes？

A級

What is Class A

Class A is the baseline. Every LoRaWAN device supports it. It’s the most power-efficient option, ideal for battery-powered devices.

How does it work?

A device sends an uplink whenever it needs to. Right after that, it opens two short receive windows — RX1 and RX2 — for possible downlinks from the network. If nothing comes in, it goes back to sleep until the next uplink. Downlink messages can only be delivered right after an uplink.

優點

–Lowest power use

–Works well for devices that send data infrequently

–Simple to deploy and scale

缺點

–High downlink latency

–Server can only send data after the device transmits

–Not suitable for real-time control

B級

What is Class B

Class B builds on Class A by adding scheduled receive slots. It’s a middle ground between Class A’s efficiency and Class C’s responsiveness.

How does it work?

The network sends out regular time-synced beacons. Devices use these IoT beacons to align their internal clocks. Alongside the two receive windows after an uplink, Class B devices also open “ping slots” at specific times. This lets the network send downlinks on schedule, reducing latency compared to Class A.

優點

–Lower downlink latency than Class A

–Can do scheduled unicast or multicast messages

–Still possible to run on batteries

缺點

–Higher power use than Class A

–Requires network and device time sync–

–Slightly more complex setup

C級

What is Class C

Class C keeps the receive window open almost all the time. It’s for applications where immediate action matters more than saving power.

How does it work?

Like Class A, there are RX1 and RX2 windows, but RX2 stays open continuously, only closing during an uplink transmission. This means the server can send a downlink almost instantly at any time. The trade-off: much higher energy use, so these devices are usually mains-powered.

優點

–Lowest downlink latency

–Real-time control possible

–Can receive data at any moment

缺點

–High power consumption

–Rarely practical for battery use

–More sensitive to network interference

The Differences of Class A, Class B and Class C?

Class A listens only right after it talks.

Class B listens after it talks and also at agreed times.

Class C listens almost all the time.

Class A uses the least power but has the longest wait for downlink. Class B trades a bit of power for faster responses. Class C is always ready but needs constant power.

Quick Showing of Different LoRaWAN Classes

常問問題

Which end device class consumes the lowest power?

Class A — because it spends most of its life asleep and only opens receive windows briefly after sending.

Which device class has the lowest downlink latency?

Class C — its receive window is open nearly all the time, so the network can send commands instantly.

Which device class is synchronized to the network using periodic beacons?

Class B — it listens for network beacons to keep its schedule aligned.