Experimental Evaluation of IEEE 802.15.4 OFDM for Wireless IoT Communication Systems

The Internet of Things (IoT) has been increasingly realizing communication among diverse devices, in addition to sensors and meters. IoT is equipped with communication functions and entails interconnection via the Internet to collect and use various data. Wireless smart ubiquitous network (Wi-SUN) conforms to the international standard IEEE 802.15.4, and it has therefore been considered a wireless communication standard for IoT. The Wi-SUN uses frequency-shift keying (FSK), standardized in IEEE 802.15.4, and achieves a typical data rate of 100 kbps. However, when Wi-SUN is used in other IoT applications to realize smart cities and smart factories, communications with higher data transmission rates and longer distances are required. Orthogonal frequency division multiplexing (OFDM), standardized in IEEE 802.15.4, has been used as a transmission method to satisfy the associated requirements. In this study, the fundamental transmission characteristics of IEEE 802.15.4 OFDM were first evaluated through computer simulations and laboratory experiments by employing developed evaluation boards. Next, the outdoor transmission performance of IEEE 802.15.4 OFDM was evaluated using the developed evaluation boards. Experimental results indicate that IEEE 802.15.4 OFDM can yield the same transmission distance as that of FSK using a smaller transmit power to achieve the packet error rate (PER) smaller than 10%.