WiRa: Enabling Cross-Technology Communication from WiFi to LoRa with IEEE 802.11ax

An developing method called Cross-Technology Communication (CTC) allows incompatible wireless technologies to be directly connected to one another. Current research suggests CTC from IEEE 802.11b to LoRa, but because of their wildly unequal data speeds, it is not very efficient. In order to achieve an efficient CTC from WiFi to LoRa, we propose in this study a WiRa protocol that uses IEEE 802.11ax to simulate LoRa waveforms. WiRa can simulate LoRa chirps using just one Resource Unit (RU) by utilizing 802.11ax's OFDMA, freeing up additional RUs for higher-rate WiFi users. In order to prevent emulation errors, WiRa carefully chooses the RU and uses WiFi frame aggregation to mimic the lengthy LoRa frame. We suggest using a subframe header mapping technique to recognize and eliminate incorrect symbols brought on by immovable subframe headers within the compiled frame. We also suggest a mode-flipping approach to address Cyclic Prefix mistakes, predicated on our discovery that distinct CP modes have disparate, even diametrically opposed effects on the emulation of a given LoRa symbol. Using a common LoRa device and the USRP platform, we deploy a WiRa prototype. Extensive testing show that WiRa can transmit full LoRa frames at a rate of 40.037 kbps while maintaining a symbol error rate (SER) below 0.1.

Keywords— Cross-Technology Communication (CTC), IEEE 802.11b, OFDMA, WiRa, LoRa.