A system may have electronic devices with wireless communications circuitry. Devices may transmit short-range wireless signals such as advertising packets. Each advertising packet may contain information on the motion context of the transmitting device. By comparing motion context information for received packets with local motion context information, an electronic device may analyze received signal strength indicator measurements with enhanced accuracy. Presence-in-vehicle state information and/or other device context may also be obtained from nearby devices by comparing local and received motion context.