US Patent 10285010 Adaptive triggering of RTT ranging for enhanced position accuracy

A range between a first wireless device and a second wireless device is estimated using a first mechanism based on messages transmitted over a first communication channel. The first communication channel is associated with a first radio access technology capability of the wireless devices. One or more metrics indicative of an accuracy of the range estimates provided by the first mechanism are obtained. A second mechanism to estimate a range between the first wireless device and the second wireless device may be implemented in favor of the first mechanism when the metric fails to satisfy a criterion. The second mechanism is based on unicast messages transmitted over a second communication channel. The second communication channel is associated with a second radio access technology capability of the wireless devices and may be the same as, or different from, the first communication channel.