Employing p-CSMA on a LoRa Network Simulator

Low-Power Wide-Area Networks (LPWANs) emerged to cover the needs of Internet of Things (IoT)-devices for operational longevity and long operating range. Among LPWANs, Long Range (LoRa) WAN has been the most promising; an upcoming IoT protocol, already adopted by big mobile operators like KPN and TTN. With LoRaWANs, IoT-devices transmit data to their corresponding gateways over many kilometers in a single hop and with 1% duty-cycle. However, in a LoRa network, any device claims the channel for data-transmission without performing channel-sensing or synchronization with other devices. This increases humongously the number of collisions of information-packets when the number of IoT-devices that are connected per gateway increases. To improve the utilization of the channel, we propose the application of persistent-Carrier Sense Multiple Access (p-CSMA) protocols on the MAC layer of LoRaWANs. In this manuscript, we report on the initial design of a p-CSMA component for the simulation of LoRa networks in ns3. In particular, the classes adding p-CSMA functionality to the IoT-devices are presented. Additionally, the dependencies and relations between these classes and an existing LoRaWAN module on which they apply are detailed. Further, we evaluate this new p-CSMA LoRaWAN module in terms of Packet Reception Ratio (PRR) by simulating LoRa networks. The current report is the first step in the creation of a holistic p-CSMA module, directed to support network-researchers and connoisseurs in simulating all aspects of LoRa networks in ns3.