Abstract: Simultaneous communication sessions between electronic devices and a server are carried on communication links each of which is at least partially wireless. Information is sent from the devices to the server information associated with proposed debit or credit transactions. The transactions are completed using an application running on the server. The communication sessions are maintained in existence during inactive periods when information about another debit or credit transaction is not waiting to be sent from one or more of the devices to the server. After the inactive periods, the maintained communication sessions are used to send, from the devices to the server, information associated with other proposed debit or credit transactions.