Software-Defined, WiFi and BLE Compliant Back-Channel for Ultra-Low Power Wireless Communication

Abstract

In this paper, we present an innovative back-channel wireless communication concept. The proposed back- channel communication enables ultra-low power (ULP) devices that are neither WiFi (IEEE 802.11a/g/n) nor Bluetooth Low Energy (BLE) compliant to receive messages from both WiFi and BLE transmitters. This allows communication between heterogeneous devices beyond the boundary of WiFi and BLE standards without hardware modification on already-deployed infrastructure. Back- channel messages are created in frequency shift keying (FSK) modulation format by feeding carefully crafted bit sequences in the payload of the WiFi or BLE packets. Systematic algorithms are introduced to embed any desired back-channel messages in FSK format on WiFi and/or BLE compliant packets. Using a commercial off-the-shelf (COTS) narrowband FSK receiver, we demonstrate successful reception of back-channel messages from WiFi and BLE transmitters. Although this COTS narrowband FSK receiver is not specifically designed for the back-channel communication, less than 1% packet error rate (PER) is achieved, validating the concept of software defined back- channel communication among heterogeneous wireless devices.