LORA architecture and frames

The figure-1 depicts LoRa network architecture. Customer information database is housed in servers. Communication between end devices and gateways are carried at different channels and different data rates. LoRa supports adaptive data rate from 0.3 Kbps to 50 Kbps.

LoRa Frame Structure

The transmission from end device to gateway is referred as "uplink" and transmission from gateway to end device is referred as "downlink". There are different classes supported in LoRaWAN network viz Class A, Class B and Class C.

As shown in figure LoRa frame consists of uplink part and downlink part. In Class-A, LoRa frame has one uplink slot followed by two downlink slots. The frame is as per TDD topology. Refer LoRaWAN classes for other LoRa classes.

LoRa Protocol Stack

The figure-2 depicts LoRa protocol stack consisting of Application layer, MAC layer, PHY layer and RF layer.
• Data from application layer and MAC commands required to establish connection between End device and gateway are carried as MAC payload.
• MAC layer constructs the MAC frame using MAC payload.
• PHY layer uses MAC frame as PHY payload and constructs the PHY frame after inserting Preamble, PHY header, PHY header CRC and entire frame CRC.
• RF layer modulates the PHY frame on required ISM RF carrier as per regulatory requirement and transmits on to the air. 

Note: Information provided on this page is derived from LoRaWAN Specification V1.0 released on Jan.2015 by LoRa™ Alliance. LoRa alliance is responsible for changes to the specifications at any time without notice. RF Wireless World is not responsible for any issues with regard to the same. Refer latest specifications published by LoRa Alliance ( https://www.lora-alliance.org ) for any changes required to be done for the products under development as per LoRa standard.