Power Savings For Network Telephones

• US 20100208724A1
• Filed: 02/13/2009
• Published: 08/19/2010
• Est. Priority Date: 02/13/2009
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Zanaty, Mohamed Kamel, Molenda, James Robert, Booth, Paul Norwood, Ristrick, John Knight JR.
• Granted Patent: US 9,065,685 B2
• Time in Patent Office: Days
• US Class Current: 370/352
• CPC Class Codes: H04L 12/10 Current supply arrangements
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements

Abstract

In an example embodiment, an IP phone is connected to a network switch that has an established communications channel to a call control server. The network switch acts as a proxy for the phone exchanging registration information that in effect keeps the phone registered while the phone itself can go to sleep as defined by periods of the day, periods where the phone is unused, or presence, which can then wake-up quickly with assistance from the switch. If the switch is not able to act as proxy, the phone can switch from sleep mode to “wake” up mode at predetermined intervals, such as every 30 seconds, in order to respond to keep alive packets from the call control server.

Claims

1. An apparatus, comprising:

a network interface;

a telephone circuit coupled to the network interface;

power save logic coupled to the telephone circuit and the network interface; and

a non-volatile memory coupled to the power save logic;

wherein the power save logic is configured to switch the telephone circuit from an active state to a power save state, the power save logic is further configured to send a signal to a switch coupled to the network interface indicating the telephone circuit is switching to the power save state and to store registration information in the non-volatile memory.

2. The apparatus as set forth in claim 1, wherein the power save logic is configured to change a signature resistance at the network interface responsive to switching the telephone circuit from the active state to the power save state.

3. The apparatus as set forth in claim 1, wherein the power save logic is further configured to store an Internet Protocol (“

IP”

) address in the non-volatile memory.

4. The apparatus as set forth in claim 1, further comprising a user interface coupled to the telephone circuit and the power save logic, wherein the power save logic is further configured to switch the telephone circuit from the power save state to the active state upon detecting activity at the user interface.

5. The apparatus as set forth in claim 1, wherein the power save logic is further configured to switch the telephone circuit from the power save state to the active state responsive to receiving a signal on the network interface indicating an incoming call for the telephone circuit.

6. The apparatus as set forth in claim 1, wherein the power save logic is configured to switch the telephone circuit from the active state to the power save state responsive to one of a group consisting of determining a current time is within a predefined time period, and determining the telephone circuit has been idle for more than a predetermined time.

7. An apparatus, comprising:

a network interface;

a telephone interface; and

logic coupled to the network interface and the telephone interface;

wherein the logic is configured to intercept and respond to packets for a telephone coupled to the telephone interface responsive to a signal received on the telephone interface that the telephone is switching to a power save state while the telephone is in the power save state.

8. The apparatus as set forth in claim 7, wherein the logic further comprises power save logic operable to disconnect power to the telephone responsive to a signal received on the telephone interface that the telephone is switching to the power save state

9. The apparatus as set forth in claim 7, wherein the logic is further configured to signal the telephone to switch to an active state responsive to detecting an incoming call.

10. A method, comprising:

initiating a transition from an active state to a power save state by a telephone coupled to a network;

sending a signal to a switch coupled to the telephone indicating the telephone is transitioning to the power save state;

storing registration information in a non-volatile memory; and

entering the power save state.

11. The method according to claim 10, further comprising changing a signature resistance to enter the power save state.

12. The method according to claim 10, wherein the storing further comprises storing an Internet Protocol (“

IP”

) address for the telephone in the non-volatile memory.

13. The method according to claim 10, further comprising initiating a transition from the power save state to the active state responsive to detecting a activity at a user input.

14. The method according to claim 10, further comprising initiating a transition from the power save state to the active state responsive to detecting a signal indicating an incoming phone call.

15. The method according to claim 10, further comprising:

initiating a transition from the power save state to the active state after a predetermined time period;

responding to a keep alive packet; and

returning to the power save state.

16. The method according to claim 10, wherein initiating the transition is responsive determining a current time is within to a predefined time period.

17. The method according to claim 10, wherein initiating the transition is responsive to detecting the telephone has been idle for greater than a predefined time period.

18. The method according to claim 10, wherein initiating the transition is responsive to receiving data indicating a user for the telephone is not present.

19. A method, comprising:

receiving a signal by a network switch from a telephone coupled to a network via the network switch that the telephone is entering a power save state;

intercepting a keep alive packet for the telephone while the telephone is in the power save state; and

transmitting a response to the keep alive packet for the telephone while the telephone is in the power save state.

20. The method of claim 19, further comprising:

receiving a signal indicating an incoming call for the telephone;

responding to the signal indicating an incoming call; and

sending a signal to the telephone instructing the telephone to exit the power save state and switch to an active state;

21. The method of claim 19, further comprising:

receiving a signal from the telephone indicating the telephone is switching to an active state; and

forwarding all packets for the telephone to the telephone responsive to the telephone switching to the active state.

22. The method of claim 19, further comprising:

detecting a change in resistance to a conductor coupled to the telephone indicating the telephone is switching to an active state; and

forwarding all packets for the telephone to the telephone responsive to the telephone switching to the active state.