Communication apparatus having power-saving communication function, and communication method

• US 20070173296A1
• Filed: 02/03/2006
• Published: 07/26/2007
• Est. Priority Date: 02/15/2005
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Nakahara, Masanori, Hara, Kazutoshi, Mashimo, Hiroshi
• Granted Patent: US 8,126,149 B2
• Time in Patent Office: Days
• US Class Current: 455/574
• CPC Class Codes: H04K 1/00 Secret communication

Abstract

A communication apparatus which starts communication using a power-saving function changes, with its communication counterpart, a key for a confidential mode and performs power-saving communication. When terminating the power-saving function, the communication apparatus returns, with its communication counterpart, the key for the confidential mode to the original one. Then, after returning the key for the confidential mode to the original one, the communication apparatus performs an IP address reassignment process.

Claims

1. A communication apparatus comprising:

a communication unit having a power-saving function configured to initiate a transition to a power-saving state; and

an encryption unit configured to transition to an encrypted communication state where a predetermined encryption key is used when the communication unit initiates the transition to the power-saving state.

2. The communication apparatus according to claim 1, further comprising an information identification determination unit configured to perform a process of determining identification information about the communication apparatus when terminating a communication state where the power-saving function is used.

3. The communication apparatus according to claim 1, wherein the predetermined encryption key is not used before transitioning to a communication state where the power-saving function is used.

4. The communication apparatus according to claim 1, wherein the predetermined encryption key is different from a first encryption key used in communication before transitioning to a communication state where the power-saving function is used, and

wherein the communication unit is configured to return to a communication state where the first encryption key is used when terminating the communication state where the power-saving function is used.

5. The communication apparatus according to claim 1, wherein if encrypted communication is not performed before transitioning to a communication state where the power-saving function is used, the communication unit is configured to return to an unencrypted communication state when terminating the communication state where the power-saving function is used.

6. The communication apparatus according to claim 1, wherein the power-saving function reduces power consumption at least during standby.

7. The communication apparatus according to claim 1, further comprising:

a determination unit configured to determine whether a new communication apparatus has joined a network which the communication apparatus joins, after transitioning to a communication state where the power-saving function is used; and

an information identification determination unit configured to perform a process of determining identification information about the communication apparatus according to determination made by the determination unit.

8. The communication apparatus according to claim 7, wherein the determination unit is configured to make the determination based on a notification signal detected after the communication state where the power-saving function is used terminates.

9. The communication apparatus according to claim 1, wherein the encryption unit is configured to transition to the encrypted communication state where the predetermined encryption key is used, when transitioning to a communication state where the power-saving function is used in an ad hoc network which allows communication apparatuses to perform direct communication.

10. A communication apparatus comprising:

a transition unit configured to transition to a communication state where a power-saving function is used; and

an information identification determination unit configured to perform a process of determining identification information about the communication apparatus when the transition unit terminates the communication state where the power-saving function is used.

11. The communication apparatus according to claim 10, further comprising:

a determination unit configured to determine whether a new communication apparatus has joined a network which the communication apparatus joins, after the transition unit has transitioned to the communication state where the power-saving function is used,

wherein the information identification determination unit is configured to perform the process of determining the identification information about the communication apparatus according to determination made by the determination unit.

12. The communication apparatus according to claim 11, wherein the determination unit is configured to make the determination based on a notification signal detected after the communication state where the power-saving function is used terminates.

13. The communication apparatus according to claim 10, wherein the information identification determination unit is configured to perform the process of deciding the identification information about the communication apparatus when terminating the communication state where the power-saving function is used in an ad hoc network which allows communication apparatuses to perform direct communication.

14. A communication method comprising:

a transition step of transitioning to a communication state where a power-saving function is used; and

an encryption step of performing encrypted communication using a predetermined encryption key when the transition step transitions to a communication state where the power-saving function is used.

15. A communication method comprising:

a power-saving communication step of performing communication using a power-saving function; and

an information identification determination step of performing a process of determining identification information about a communication apparatus when terminating a communication state where the power-saving function is used.