LoRaWAN Protocol Stack Layers as per LoRa Standard
This page describes LoRaWAN protocol stack basics. The protocol layers of LoRaWAN stack include radio frequency layer, physical layer, MAC layer and application layer.
The terms LoRa stands for Long Range where as LoRaWAN stands for LoRa Wide Area Network. The technology has been designed to offer wide long range and low energy consumption. This wireless system uses different radio frequency bands for different regions such as 902 to 928 MHz band is used in US, 863-870 MHz/433-434 MHz in Europe and 470-510 MHz/779-787 MHz in China and so on.
LoRaWAN protocol stack
LoRaWAN consists of end devices, gateway and servers. There are two types of frame viz. uplink (from end device towards gateway/server) and downlink (from server/gateway towards end device).
The LoRaWAN protocol stack consists of following layers.
RF Layer: It takes care of radio frequency assignment and transmission of baseband information using RF carrier with the help of antenna over the air. The different frequency bands are allocated for different regions of the world.
Physical Layer: The layer lies above RF and it has many functions. It takes care of preamble , header formation, CRC for header and entire frame as shown in the figure-2. The raw data of the frame is later modulated using LoRa CSS/FSK or GFSK before necessary RF conversion for uplink transmission. Coverage, interference and optimization of RF issues are handled by physical layer.
MAC Layer: It takes care of MAC management messages between end device and server. Moreover MAC header, MIC and other MAC layer fields are used for specific purposes. MAC handles major fuctions such as energy consumption, security (AES128 Encryption) and mesh topology.
MAC layer takes care of different classes of end devices viz. class-A, Class-B and class-C.
➨Refer LoRaWAN MAC >> for complete information on MAC layer.
Class-A : Most energy efficient (Must be supported by all end nodes, DL after Tx
Class-B : Efficient with controlled DL (Slotted communication synchronized with beacon frames)
Class-C : Least Efficient (Devices listen continuously. DL without latency)
➨Refer LoRaWAN Classes >> for more information.
Application Layer: It is designed based on usage such as health care, smart city,
smart farming, smart grid and so on.
Reference: LoRaWAN specifications published by LoRa Alliance ( https://www.lora-alliance.org ).
LoRaWAN related links
The LoRaWAN Wireless tutorial covers following sub topics:
LoRaWAN Smart Parking LoRaWAN sensor design LoRaWAN smart healthcare system LoRaWAN smart water metering LoRaWAN architecture LoRaWAN Interface Types LoRaWAN roaming types LoRa tutorial LoRa Frequency Bands LoRa protocol stack LoRa MAC layer LoRaWAN classes LoRa features LoRa Transceiver module