the time to live field the communication hub 202 may perform other actions based upon the receipt of the acknowledge message 306 such as initiating a transaction in a retail system performing a database lookup unlocking the user device 100 logging into the user 39 s account being accessed by the browser running on the user device 100 and recording the presence of the user device 100 in proximity to the communication hub in a loyalty card application the user device 100 has a number of sensors and actuators integrated with one or more radio transceivers 114 118 122 it can be used to provide user interaction to multiple applications where the application business logic is implemented on a computer system remote to the user device 100 in such embodiments performing a gesture such as a double tap tap tap pushing a button 106 or simply being in a particular place or combination of place and time can cause the business logic to implement a particular action which is dependent on the user the location the gesture performed the date and time and the presence or absence of other co located users the business logic is responsible for determining and implementing the required action based on the collection of information including for example the location the gesture performed the date and time and the presence or absence of other co located users collectively called the users context fig4 illustrates an embodiment in which the user device 100 explicitly sends.