Method and device with dynamic dormancy

1. A method for saving energy in a device configured to maintain a persistent Internet Protocol (IP) communication session over a wireless network with an application server, the method comprising:

opening, at the device, the persistent IP communication session with the application server via the wireless network;

measuring, at the device, a round-trip time from sending a message to the application server to receiving an acknowledgement message from the application server; and

transitioning, at the device, from a first operating state to a second operating state after an amount of time, exceeding a predetermined threshold, during which there is an absence of subsequent data traffic, wherein power consumption associated with the second operating state is less than power consumption associated with the first operating state, wherein the predetermined threshold is a function of the measured round-trip time, and wherein the predetermined threshold is a function of an expected amount of time before the device sends a subsequent message, the expected amount of time being based on a likelihood of a running application sending the subsequent message.

2. The method of claim 1 wherein the expected amount of time before the device sends a subsequent message is dependent upon a set of applications running on the device.

3. The method of claim 2 wherein if the set of applications running on the device includes a web browser, then the predetermined threshold is increased.

4. The method of claim 1 wherein the device comprises a transmitter arrangement and a receiver arrangement and wherein transitioning the device to the second operating state comprises disabling at least one of the transmitter arrangement and the receiver arrangement.

5. A wireless communication device comprising:

a housing;

a controller coupled to the housing, the controller configured to operate the wireless communication device;

memory coupled to the controller;

a wireless transceiver coupled to the controller, the wireless transceiver configured to maintain a persistent Internet Protocol (IP) communication session over a wireless network with an application server; and

a dynamic dormancy module configured to:

open the persistent IP communication session with the application server via the wireless network;

measure a round-trip time from sending a message to the application server to receiving an acknowledgement message from the application server; and

transition the device from a first operating state to a second operating state after an amount of time, exceeding a predetermined threshold, during which there is an absence of subsequent data traffic, wherein power consumption associated with the second operating state is less than power consumption associated with the first operating state, wherein the predetermined threshold is a function of the measured round-trip time, and wherein the predetermined threshold is a function of an expected amount of time before the device sends a subsequent message, the expected amount of time being based on a likelihood of a running application sending the subsequent message.

6. The wireless communication device of claim 5 wherein the expected amount of time before the device sends a subsequent message is dependent upon a set of applications running on the device.

7. The wireless communication device of claim 6 wherein if the set of applications running on the device includes a web browser, then the predetermined threshold is increased.

8. The wireless communication device of claim 5 wherein the device comprises a transmitter arrangement and a receiver arrangement and wherein transitioning the device to the second operating state comprises disabling at least one of the transmitter arrangement and the receiver arrangement.