Differences between digital mapping data and actual propagation conditions in urban canyon environments challenge most geographical routing algorithms proposed for use in Vehicular Ad Hoc Networks (VANETs). We explore a strategy for capturing this complex, time-variant, radio-frequency (RF) propagation environment. We demonstrate that spatial loss behaviors in urban canyon propagation topographies can be reconstructed from measurements with useful fidelity using a tomographic estimation algorithm. The algorithm uses measurements of Received Signal Strength (RSS) seen by VANET nodes and the geographical positions of these nodes at the time of measurement. Simulation of tomographic reconstructions for monotonically increasing positioning errors, which are typical of Global Navigation Satellite System (GNSS) based positioning schemes, demonstrated useful fidelity and good convergence, even for positioning errors that are typical in low-cost commodity hardware.
- received signal strength (RSS)
- urban canyon
- vehicular ad hoc network (VANET)