A location of a network user computing device is determined relative to a location of a point of interest. Accordingly, the present invention further provides a method for implementing impedance matching of an electromagnetic immunity filter. The MSC sends a request along with radio information to a location processor, which controls the RDF devices. The first and the second electrodes are formed on the insulating layer. For example, the controller operates the engine lean, with periodic rich operation to purge stored NOx during at least a portion of low engine airflow and low exhaust temperature conditions. The epitaxial structure is treated to cause the strained layer to relax.