LoRaWAN Classes | Class A,Class B,Class C | RF Wireless World
This page of RF Wireless World Covers LoRa wireless device classes. The LoRa classes include Class A, Class B, Class C used for different functionalities.
LoRa network composed of end devices and gateways. Based on MAC layer there are three classes of end devices in LoRa network. The classes are defined as Class A, Class B and Class C.
All the LoRa classes based end devices are bi-directional in nature for communication. Following section mentions basic features of these LoRa class types.
LoRa Class A End Devices
Following are the features of LoRa Class A end devices:
• The frame in general is devided into uplink transmission and downlink transmission. Uplink is consists of 1 slot followed by 2 downlink slots (or windows).
• Uplink slot is scheduled by End device itself based on its need. It is decided on random basis similar to ALOHA protocol.
• It is the lowest power LoRa end device.
LoRa Class B End Devices
Following are the features of LoRa Class B end devices:
• This class of end devices use extra receive windows during downlink period in addition to two time slots specified in class-A.
• Class B devices will get extra receive windows at specified duration.
• The duration is specified by the gateway using beacon frame.
• Hence this way LoRa system indicates to the server when end device can listen.
LoRa Class C End Devices
Following are the features of LoRa Class C end devices:
• This class of end devices can listen all the time except in transmit mode. Hence it is ideal for applications requiring more downlink transmissions.
• Class C LoRa end device will utilize more power compare to Class A and Class B counterparts.
• It has lowest latency among all the LoRa class end devices for data communication between server and end device.
Following table summarizes difference between class A, class B and class C types used in LoRa.
|LoRa Class A||LoRa Class B||LoRa Class C|
|Battery Powered||Low Latency||No Latency|
|Bidirectional communications||Bidirectional with scheduled receive slots||Bidirectional communications|
|Unicast messages||Unicast and Multicast messages||Unicast and Multicast messages|
|Small payloads, long intervals||Small payloads, long intervals, Periodic beacon from gateway||Small payloads|
|End-device initiates communication (uplink)||Extra receive window (ping slot)||Server can initiate transmission at any time|
|Server communicates with end-device (downlink) during predetermined response windows||Server can initiate transmission at fixed intervals||End-device is constantly receiving|
Note: Information provided on this page is derived from LoRaWAN Specification V1.0 released on Jan.2015 by LoRa™ Alliance. Refer latest specifications published by LoRa Alliance ( https://www.lora-alliance.org ).