A method for modulating a sequence of data symbols such that the transmit signal exhibits spectral redundancy. By implementing the present invention, a user terminal in IDLE mode only needs a predefined period such as a DRX period to wake up to receive the notification indicator to judge whether a new service will start without waking up at extra time. The customer interaction process may also include retrieving banking product information associated with a banking product and conducting at least one sales activity using the banking product information. If the condition has been resolved, the computing device causes the virtual machine to be resumed.