A navigation assistance system is provided. At least one RF backscatter transmitter, hosted on a device, is configured to emit a RF signal on a frequency. A set of passive RF backscatter tags, each associated with a respective one of a plurality of navigation markers in a given venue, is configured to reflect the RF signal and frequency shift the RF signal to a different frequency. At least one RF backscatter receiver is configured to read the navigation markers on the different frequency by detecting a distributed ambient backscatter signal generated by a reflection and frequency shifting of the RF signal by the passive RF backscatter tag. At least one of the device hosting the at least one RF backscatter transmitter and the other device hosting the at least one RF backscatter receiver is configured to maintain an inventory of locations of the navigation markers in the given venue.