A system for processing transactions, having a base station having a processor, a storage device configured to store a payment module, downloaded from a module provider, a Wi-Fi communication module, and a terminal management system configured to control the processor, storage device and the Wi-Fi communication module; and at least one mobile device having a processor, a payment user interface configured to allow a user to perform payment transactions with the payment module, a Point of Sale (POS) module configured to perform Point of Sale operations, and a Wi-Fi Communication module, wherein the terminal management system is configured to authenticate a payment module being downloaded and to cause the processor of the base station to prevent the payment module from being installed on the storage device if the payment module is not authenticated by the terminal management system.