Abstract: A system and method for generating a one-dimensional spatial index and a temporal index in relation to one or more two-dimensional location points of one or more mobile devices to enable near-real-time searching of devices having fast-changing location information is provided for. The present invention may be used in a variety of implementations including being used in conjunction with searching for mobile devices within a geographical area for a time period; finding nearby devices within a time period; tracking device movement within a time period; determining clusters of devices for identification and location across different geographical regions at once.

Abstract: To select a shoulder-tap method or a set of methods that optimizes the delivery of a shoulder-tap with respect to feasibility, reliability, and cost, in accordance with the present invention. Each shoulder-tap method can be evaluated on its feasibility, reliability and cost. A shoulder-tap method can be selected and used that optimizes reliability and cost with respect to feasibility constraints.