Interconnecting WiFi Devices with IEEE 802.15.4 Devices without Using a Gateway

In many wireless sensing and control application deployments, there is often a gateway device to bridge between the low power IEEE 802.15.4 network and the Internet. The bridge has at least two interfaces. One interface communicates with the 802.15.4 wireless. The other interface either communicates with Wi-Fi or wired network. When a user wants to send a command to the wireless controller, lets say at a smart home, the user may use a smartphone and send command over Wi-Fi to the gateway, often through a cloud service provider. Then gateway shuttles the message from the wired or Wi-Fi chip to the 802.15.4 chip. Then the gateway transmits the messages over the 802.15.4 chip into the 802.15.4 network. In this work, we design a novel modulation technique that runs on the Wi-Fi devices (e.g., Smartphone) and demodulation technique that runs on 802.15.4 devices (e.g., A wireless controller in a smart home) to enable Wi-Fi devices to directly communicate with 802.15.4 devices without any gateway. The key idea is to utilize crosstalk between 802.11 and 802.15.4 channels as the medium for communication. We implemented the proposed technique on multiple platforms and are able to successfully achieve a data rate of 2 bytes per second with less than 10% bit error rate in uncontrolled environments.