Analyses of Hidden and Exposed Nodes in LPWAN with Energy Detection Based Carrier Sense

This study investigates hidden and exposed nodes in a low power wide area network (LPWAN) with the energy detection based carrier sense. Energy detection based carrier sense can drastically improve the performance of LPWANs, which is a type of wireless local network. However, hidden node problems are inherent in wireless local networks with carrier sense, and the upsurge of LPWANs with carrier sense results in exposed node problems. To evaluate the hidden and exposed nodes in the LPWAN, we define evaluation model that includes Own LPWAN and Interference LPWAN. Based on the model, hidden and exposed nodes in the LPWAN are evaluated for different distance between both LPWANs and different path loss exponent between end devices and gateway. The evaluation results show that exposed nodes are not expected to occur in the LPWAN when the gateway is located at the appropriate location where many of the end devices are located in the line-of-sight environment.