Multi-Channel Two-Way Time of Flight Sensor Network Ranging
Two-way time of Flight (ToF) ranging is one of the most interesting approaches for localization in wireless sensor networking since previous ToF ranging approaches using Commercial Off-The-Shelf (COTS) devices have achieved good accuracy. The COTS-based approaches were, however, evaluated only in line-of-sight conditions. In this paper, the authors extend ToF ranging using multiple IEEE 802.15.4 channels. Their results demonstrate that with multiple channels they can achieve good accuracy even in non line-of-sight conditions. Furthermore, their measurements suggest that the variance between different channels serves as a good estimate of the accuracy of the measurements, which can be valuable information for applications that require localization information.