Abstract: The subject matter of this specification can be embodied in, among other things, a method that includes accessing a data structure that includes information about purchasers, merchants, and financial transactions between the purchasers and the merchants and generating purchaser clusters. Generating purchaser clusters includes clustering the purchasers based on which purchasers make purchases from the same or similar merchants. Each purchaser cluster adopts associations between purchasers belonging to the purchase cluster and merchants from which these purchasers have made purchases. The method also includes generating merchant clusters, where generating the merchant clusters includes clustering merchants based on which merchants are associated with the same or similar purchase clusters and outputting profile information that characterizes typical purchases associated with one or more of the merchant clusters for use in detecting fraudulent transactions.

Abstract: A cellular system uses dynamic repartitioning and channel packing to improve capacity without impacting quality. Dynamic repartitioning is employed to convert a carrier which operates, at one time, as an analog carrier to operate, at a later time, as a digital carrier in response to changes in offered traffic. Alternatively, a carrier which, at one time, operates as a digital carrier is converted to operate, at a later time, as an analog carrier in response to changes in offered traffic. The system also supports multiple digital protocols so that a carrier can also be converted to operate in any one of several different digital modes. Channel packing is used to allocate as many digital channels as possible to as few digital carriers as possible. In a preferred embodiment, both repartitioning and channel packing are implemented in response to a request for a channel allocation or deallocation.

Abstract: A cellular system uses dynamic repartitioning and channel packing to improve capacity without impacting quality. Dynamic repartitioning is employed to convert a carrier which operates, at one time, as an analog carrier to operate, at a later time, as a digital carrier in response to changes in offered traffic. Alternatively, a carrier which, at one time, operates as a digital carrier is converted to operate, at a later time, as an analog carrier in response to changes in offered traffic. Channel packing is used to allocate as many digital channels as possible to as few digital carriers as possible. In a preferred embodiment, both repartitioning and channel packing are implemented in response to call origination or call termination.