Advanced power saving in communication terminal, communication system and power control method

• US 20050233704A1
• Filed: 04/14/2005
• Published: 10/20/2005
• Est. Priority Date: 04/16/2004
• Status: Active Grant

• Current Assignee: Sony Computer Entertainment Incorporated (Sony Group Corp.)
• Original Assignee: Sony Computer Entertainment Incorporated (Sony Group Corp.)
• Inventors: Maekawa, Itaru
• Granted Patent: US 7,949,376 B2
• Time in Patent Office: Days
• US Class Current: 455/69
• CPC Class Codes: H04L 12/12 Arrangements for remote connection or disconnection of substations or of equipment thereof
• CPC Class Codes: H04L 47/56 implementing delay-aware scheduling
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/9031 Wraparound memory, e.g. overrun or underrun detection
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Each station makes a transition to a power saving state autonomously in response to the reception of signals from the other stations in the same group and the transmission of its own signal. Each station sets its transmission timing such that it does not overlap the transmission timing of the other stations, by referring to data elements included in a beacon signal. The transmission timing in the stations is determined for each transmission.

Claims

1. A communication terminal which constitutes a group with at least one other communication terminal and communicates within the group, comprising:

a receiver unit which receives a data signal from the at least one other communication terminal;

a reception controller which counts the number of data signals received from the at least one other communication terminal; and

a power controller which enters a power saving mode by referring to the number of data signals counted.

2. The communication terminal according to claim 1, further comprising a transmitter unit which sends a data signal to the at least one other communication terminal;

wherein the power controller enters the power saving state by referring to the number of data signals counted and by learning that the communication terminal has sent its own data signal.

3. The communication terminal according to claim 2, wherein the transmitter unit transmits a predetermined broadcast signal.

4. The communication terminal according to claim 1, wherein the reception controller notifies the power controller of the reception of data signals from the other communication terminal constituting the group, and the power controller enters the power saving state in response to the notification.

5. The communication terminal according to claim 2, wherein the transmitter unit transmits a data signal in response to the transmission or reception of a predetermined broadcast signal.

6. The communication terminal according to claim 5, wherein the power controller leaves the power saving state and enters an active state before the transmission or reception of the broadcast signal.

7. The communication terminal according to claim 1, wherein the reception controller monitors a communication environment and notifies the power controller when a non-communication period exceeds a predetermined period of time, and the power controller enters the power saving state in response to the notification.

8. The communication terminal according to claim 7, wherein the predetermined time is set to be longer than the longest of intervals between transmission times determined respectively in the communication terminals constituting the group.

9. The communication terminal according to claim 5, wherein data elements for determining a transmission timing are included in the broadcast signal, and wherein the communication terminal is further provided with a transmission controller for determining the transmission timing for transmission of its own data signal by referring to the data elements in the broadcast signal.

10. A power control method comprising the steps of:

receiving a data signal from at least one other communication terminal constituting a group;

counting the number of data signals received from the at least one other communication terminal; and

entering a power saving state by referring to the number of data signals counted.

11. A program which causes a computer to carry out the functions of:

receiving a data signal from at least one other communication terminal constituting a group;

counting the number of data signals received from the at least one other communication terminal; and

entering a power saving state by referring to the number of data signals counted.

12. A communication system for communication between a plurality of communication terminals, comprising:

a first power saving mode in which the plurality of communication terminals enter a sleep state when one of the plurality of communication terminals transmits a broadcast signal; and

a second power saving mode in which each of the plurality of communication terminals enters a sleep state autonomously by learning that the number of data signals received from one or more other communication terminals has reached a predetermined value.