Issue link: https://read.uberflip.com/i/1507762
Enabling CSMA for LoRaWAN TR013-1.0.0 ©2023 LoRa Alliance ® Page 5 of 18 The authors reserve the right to change specifications without notice. 2 Introduction 109 110 LoRaWAN specification [TS001] adopts ALOHA mode as the Media Access Control (MAC) 111 mechanism for channel (CH) access. The ALOHA MAC mechanism implies that whenever an 112 end-device is ready to transmit a frame, it is transmitted regardless of the condition of the 113 channel. This mechanism results in a high probability of frame collisions under congested 114 networks. Alternatively, Carrier Sense Multiple Access (CSMA) can allow LoRaWAN nodes to 115 verify the absence of potential collisions before transmitting on a shared medium. However, 116 enabling CSMA under LoRa modulation entails unique challenges. This document provides 117 recommendations for LoRaWAN devices to minimize such collisions by enabling CSMA in 118 conjunction with the LoRaWAN specification. 119 120 The proposed mechanism in this document is fully compatible with the LoRaWAN 121 specification. As such, incorporating the recommended additions in this document does not 122 require changes to other LoRaWAN subsystems, such as gateways, network servers, and 123 application servers. At the same time, end-devices enabled with CSMA co-exist and contribute 124 towards a positive impact on the entire network. 125