Communication device and communication method

• US 7,944,867 B2
• Filed: 02/17/2006
• Issued: 05/17/2011
• Est. Priority Date: 02/17/2005
• Status: Expired due to Fees

• Current Assignee: Pioneer Corporation
• Original Assignee: Pioneer Corporation
• Inventors: Usuba, Hidemi
• Primary Examiner(s): HSU, ALPUS
• Application Number:
  US11/816,135
• Publication Number:
  US 20090040954A1
• Time in Patent Office: 1,915 Days
• Field of Search: 370/311, 370/338, 455/69, 455/343.4, 455/574
• US Class Current: 370/311
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A control unit controls setting of an operating mode. A timer determines a transmission period of a beacon for notifying presence of a network. A beacon transmitting unit transmits a beacon based on the transmission period. When the control unit instructs to switch from a normal operation mode to a power-saving operation mode, the timer sets a transmission period of the beacon to be longer than a transmission period in the normal operation mode.

Claims

1. A communication device that functions as an access point in a radio communication system and notifies presence of a network to a station in the radio communication system, the communication device comprising:

a control unit that controls setting of an operating mode including a normal operation mode and a power-saving operation mode;

a timer that determines a transmission period of a beacon for notifying the presence of the network;

a beacon transmitting unit that transmits the beacon to the station based on the transmission period; and

a sleep control unit that sets all circuits other than the timer and the sleep control unit, to be in a sleep state when the control unit instructs to switch from the normal operation mode to the power-saving operation mode, wherein

when the control unit instructs to switch from the normal operation mode to the power-saving operation mode, the timer sets the transmission period of the beacon to be longer than a transmission period in the normal operation mode, and

during operation in the power-saving operation mode, the timer notifies a wake-up request at a timing earlier than a transmission timing of the beacon by a first time to the sleep control unit and further notifies a sleep request after a second time has passed from the transmission timing of the beacon to the sleep control unit, and when receiving the wake-up request, the sleep control unit supplies a power to circuits except the timer, the sleep control unit, and the control unit, and resets the circuits except the timer, the sleep control unit, and the control unit to be in the sleep state when receiving the sleep request.

2. The communication device according to claim 1, wherein the sleep control unit supplies the power to the control unit when the communication device receives a network participation request from the station during a time period from the transmission timing of the beacon to a passage of the second time, during operation in the power-saving operation mode, and controls to return the transmission period of the beacon to the transmission period in the normal operation mode when the control unit instructs to switch from the power-saving operation mode to the normal operation mode.

3. The communication device according to claim 1, wherein the control unit instructs to switch to the power-saving operation mode when a total number of stations participating in the network becomes zero or when no signal is received from any one of the stations participating in the network over a predetermined time period during operation in the normal operation mode.

4. The communication device according to claim 1, wherein the network is a basic service set in a wireless local area network system.

5. The communication device according to claim 1, wherein the network is a piconet in a wireless personal area network system.

6. A communication device that functions as a station in a radio communication system including an access point that includes a mode control unit that controls setting of a normal operation mode and a power-saving operation mode, a timer that determines a transmission period of a beacon for notifying presence of a network, a beacon transmitting unit that transmits the beacon based on the transmission period, and a sleep control unit that sets all circuits including the mode control unit and the beacon transmitting unit other than the timer, which are related to data transmission/reception, to be in a sleep state when the mode control unit instructs to switch from the normal operation mode to the power-saving operation mode, wherein when the mode control unit instructs to switch from the normal operation mode to the power-saving operation mode, the timer sets the transmission period of the beacon so as to be longer than that in the normal operation mode, during operation in the power-saving operation mode, the timer notifies a wake-up request at a timing earlier to the sleep control unit, by a first time, than a transmission timing of the beacon that is transmitted at a longer interval than that in the normal operation mode, further notifies a sleep request after a second time has passed from the transmission timing of the beacon to the sleep control unit, when receiving the wake-up request, the sleep control unit supplies a power to circuits except the timer, the sleep control unit, and the control unit, and resets the circuits except the timer, the sleep control unit, and the control unit to be in the sleep state when receiving the sleep request, and that recognizes the presence of the network by the beacon sent from the access point in the radio communication system, the communication device comprising:

a control unit that controls a participation in the network;

a beacon receiving unit that receives the beacon transmitted by the access point; and

a network-participation-procedure control unit that transmits a network participation request from the station based on a network-participation-procedure start request sent from the control unit, wherein

the network-participation-procedure control unit transmits the network participation request from the station during a time period until the second time has passed in the access point after reception of the beacon that is transmitted at a longer interval than that in the normal operation mode, during operation of the access point in the power-saving operation mode.

7. The communication device according to claim 6, wherein the network is a basic service set in a wireless local area network system.

8. The communication device according to claim 6, wherein the network is a piconet in a wireless personal area network system.

9. A communication method implemented by a communication device that functions as an access point in a radio communication system when the access point notifies presence of a network to a communication device that functions as a station in the radio communication system by a beacon, the communication method comprising:

switching to a power-saving operation mode, when a total number of stations participating in the network becomes zero or when no signal is received from any one of the stations participating in the network over a predetermined time period during operation in a normal operation mode, setting a transmission period of the beacon to be longer than a transmission period thereof in the normal operation mode, and setting all circuits other than a timer, which are related to data transmission/reception, to be in a sleep state;

supplying power to circuits except a timer, a sleep control unit, and a control unit, at a timing earlier, by a first time, than a transmission timing of the beacon that is transmitted at a longer interval than that in the normal operation mode, during operation in the power-saving operation mode from the transmission timing of the beacon;

setting the circuits to be in a sleep state after a second time has passed from the transmission timing of the beacon; and

switching to the normal operation mode when the access point receives a network participation request from one of the stations during a time period from the transmission timing of the beacon to the passage of the second time, during operation in the power-saving operation mode, and returning the transmission period of the beacon to the transmission period in the normal operation mode.

10. The communication method according to claim 9, wherein the network is a basic service set in a wireless local area network system.

11. The communication method according to claim 9, wherein the network is a piconet in a wireless personal area network system.