A method (200) and device (300) for saving energy in a wireless communication device configured to maintain a persistent communication session over a wireless network with an application server. The method (200) can include: opening (210) a persistent communication session with an application server via a cellular network; measuring (220) a round trip time (RTT) from sending a message to theapplication server to receiving an acknowledgement message from the application server; and automatically transitioning (230) the device from a first operating state to a second operating state after an amount of time in the absence of subsequent data traffic exceeding a predetermined threshold, wherein power consumption associated with the second operating state is less than power consumption associated with the first operating state, and the predetermined threshold is a function of the measured round trip time. Advantageously, the method (200) can measure the actual RTT and transition to a low power based on the measured RTT exceeding a predetermined threshold, before the expiration of a network configured inactivity timer and in the absence of subsequent data traffic, which helps to minimize unnecessary power drain in a wireless communication device and minimizes inefficiencies in connection with data exchanges between a network and a wireless communication device.