<p>Some implementations of the invention involve forming "logical" or "virtual" devices by aggregating a plurality of physical devices. The physical devices may be, for example, controllers, RFID readers and/or storage devices. Some logical devices comprise components of physical devices, such as individual antennas from a plurality of RFID readers. The physical devices may be located near one another or may be distributed over a wide geographical area. Logical device definitions can also be concatenated to include devices having two or more levels of logical device definitions. A single logical device grouping may include physical devices at differing levels of a network hierarchy.</p>
