Issue link: https://read.uberflip.com/i/1428383
LoRaWAN 1.0.3 Specification ©2018 LoRa™ Alliance Page 40 of 72 The authors reserve the right to change specifications without notice. 8 Introduction to Class B 1093 This section describes the LoRaWAN Class B layer which is optimized for battery-powered 1094 end-devices that may be either mobile or mounted at a fixed location. 1095 End-devices should implement Class B operation when there is a requirement to open receive 1096 windows at fixed time intervals for the purpose of enabling server initiated downlink messages. 1097 LoRaWAN Class B option adds a synchronized reception window on the end-device. 1098 One of the limitations of LoRaWAN Class A is the Aloha method of sending data from the end- 1099 device; it does not allow for a known reaction time when the customer application or the server 1100 wants to address the end-device. The purpose of Class B is to have an end-device available 1101 for reception at a predictable time, in addition to the reception windows that follows the random 1102 uplink transmission from the end-device of Class A. Class B is achieved by having the gateway 1103 sending a beacon on a regular basis to synchronize all end-devices in the network so that the 1104 end-device can open a short additional reception window (called "ping slot") at a predictable 1105 time during a periodic time slot. 1106 Note: The decision to switch from Class A to Class B comes from the 1107 application layer of the end-device. If this class A to Class B switch 1108 needs to be controlled from the network side, the customer application 1109 must use one of the end-device's Class A uplinks to send back a 1110 downlink to the application layer, and it needs the application layer on 1111 the end-device to recognize this request – this process is not managed 1112 at the LoRaWAN level. 1113