A system includes a plurality of networked nodes spatially distributed within a monitored area and adapted to interact with a mobile entity entering and moving through the area, the plurality of nodes including at least one area entrance node adapted to detect the mobile entity upon entering the monitored area, and a transaction node for accomplishing a transaction with the mobile entity; a transaction processing center in communication relationship with the nodes for processing data required for the transaction and for providing the data to the transaction node. A node selection unit is adapted to dynamically select the transaction node among the plurality of nodes based on an estimation of the speed of movement of the mobile entity.