IP address acquisition method for controlling standby mode of set-top box, and set-top box and power management server performing the method

1. A method of acquiring an Internet protocol (IP) address of a set-top box performed by a power management server, the method comprising:

determining whether a state of a set-top box changes from a broadcasting state in which a broadcasting service is provided to a passive standby state in which a network connection between the set-top box and a headend providing the broadcasting service is blocked;

receiving, from the set-top box, state information associated with an IP address allocated to the set-top box for the network connection in response to the state of the set-top box changing to the passive standby state;

reducing a power consumption of the set-top box in response to the state of the set-top box changing to the passive standby state;

transmitting, to the set-top box, a state change command to maintain the network connection for the IP address allocated to the set-top box based on the received state information;

transmitting, through a separate microcontroller processor of the set-top box, a state change command in response to a state maintenance time of routing information of the set-top box being exceeded; and

broadcasting a video content to the set-top box.

2. The method of claim 1 , wherein the determining comprises:

determining whether the state of the set-top box changes from an active standby state to the passive standby state after the state of the set-top box changes from the broadcasting state to the active standby state in which the broadcasting service is not provided and the network connection between the set-top box and the headend is available.

3. The method of claim 1 , wherein the state information associated with the IP address comprises at least one of a time at which the set-top box enters the passive standby state, the IP address of the set-top box and a media access control (MAC) address of the set-top box, and a lease time for the IP address allocated to the set-top box.

4. The method of claim 1 , wherein the transmitting comprises:

detecting the state maintenance time of routing information of the set-top box; and

transmitting, to the set-top box, the state change command based on the detected state maintenance time of the routing information and the state information.

5. The method of claim 4 , wherein the detecting comprises:

detecting the state maintenance time of the routing information maintained in the set-top box when the state of the set-top box changes to the passive standby state.

6. The method of claim 4 , wherein the transmitting comprises:

transmitting, to the set-top box, the state change command before the IP address allocated to the set-top box is retrieved by an IP management server based on the state maintenance time and the state information.

7. The method of claim 1 , wherein the set-top box is configured to change the state of the set-top box from the passive standby state to an active standby state based on the state change command received from the power management server, and receive a reallocated IP address from the IP management server or extend use of the allocated IP address, and maintain the network connection.

8. The method of claim 1 , wherein the state change command is configured to activate the set-top box to receive a reallocated IP address from an IP management server or extend use of the allocated IP address by changing the state of the set-top box from the passive standby state to an active standby state.

9. A method of acquiring an Internet protocol (IP) address performed by a set-top box, the method comprising:

receiving an IP address allocated by an IP management server configured to manage the IP address of the set-top box for a network connection between the set-top box and a headend when power is input to the set-top box;

determining whether a state of the set-top box changes from a broadcasting state in which a broadcasting service is provided to a passive standby state in which the network connection is blocked;

transmitting, to a power management server, state information associated with the IP address allocated to the set-top box when the state of the set-top box changes to the passive standby state;

reducing a power consumption of the set-top box in response to the state of the set-top box changing to the passive standby state;

receiving, from the power management server, a state change command to maintain the network connection for the IP address allocated to the set-top box in response to the state information;

maintaining the network connection for the IP address by changing the state of the set-top box to an active standby state in which the network connection of the set-top box is available in response to the received state change command;

receiving, at a separate microcontroller processor of the set-top box, a state change command in response to a state maintenance time of routing information of the set-top box being exceeded; and

receiving broadcast video content at the set-top box.

10. The method of claim 9 , wherein the power management server is configured to transmit, to the set-top box, the state change command to receive a reallocated IP address from the IP management server or extend use of the allocated IP address before the IP address allocated to the set-top box is retrieved by the IP management server based on a lease time for the IP address included in the state information.

11. The method of claim 9 , wherein the maintaining comprises:

changing the state of the set-top box from the passive standby state to the active standby state in response to the state change command;

transmitting, to the IP management server, a usage message on use of the IP address in the active standby state before the lease time for the IP address allocated by the IP management server is terminated; and

receiving a response message to the usage message on the use of the IP address from the IP management server, and maintaining the network connection for the IP address of the set-top box in response to the response message.

12. The method of claim 11 , wherein the usage message on the use of the IP address includes information about a request for extension of the use of the IP address allocated to the set-top box or information about a request for allocation of a new IP address, and

the response message includes at least one of information about a lease time for extended use of the IP address allocated to the set-top box and information about a lease time for use of the new IP address reallocated to the set-top box.

13. The method of claim 9 , further comprising:

changing the state of the set-top box from the active standby state to the passive standby state after the network connection for the IP address of the set-top box is acquired.

14. The method of claim 9 , wherein the set-top box is configured to maintain the passive standby state or change the state of the set-top box from the passive standby state to the active standby state after the state of the set-top box changes to the passive standby state, based on whether the lease time for the IP address has elapsed and whether the state change command is received.

15. The method of claim 1 , wherein, in response to the state maintenance time of the routing information of the set-top box being exceeded, the routing information of the set-top box is discarded, the routing information comprising the IP address and a MAC address.

16. The method of claim 1 , further comprising extending the state maintenance time based on the state information using an IP stack processor.

17. The method of claim 1 , further comprising not reducing a power consumption of the set-top box in response to the maintenance time for the routing information being less than or equal to a standby time.

18. The method of claim 9 , further comprising recognizing a network interface controller, an audio-visual driver, a demultiplexer, a descrambler, and a filesystem.