Multicast transmission for power management in an ad-hoc wireless system

• US 9,311,446 B1
• Filed: 03/19/2010
• Issued: 04/12/2016
• Est. Priority Date: 03/19/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Sathyamurthy, Dhanasekaran, Panneerselvam, Sivakumar
• Primary Examiner(s): Smith, Marcus R
• Assistant Examiner(s): Rahgozar, Omeed D
• Application Number:
  US12/727,610
• Time in Patent Office: 2,216 Days
• Field of Search: 370310-315, 340 732- 734, 4554221-460
• US Class Current: 1/1
• CPC Class Codes: H04L 12/1877 Measures taken prior to transmission
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04W 40/244 using a network of reference devices, e.g. beaconing

Abstract

In an ad-hoc wireless network, a single multicast message can be used to announce availability of queued data to one or more WLAN devices in the ad-hoc network. A wireless network device in the ad-hoc network can determine network identifiers associated with the other wireless network devices in the ad-hoc network for which the queued data is available. The wireless network device transmits the multicast message, which identifies the wireless network devices for which queued data is available, to indicate the wireless network devices that should remain in an active power state. On receiving the multicast message, a receiving WLAN device can read a network identifier bit associated with the receiving WLAN device to determine whether or not the receiving WLAN device should remain in the active power state. This can reduce transmission overhead and improve power savings, efficiency, and data reliability.

Claims

1. A method for power management, the method comprising:

identifying, by a first wireless network device, a second wireless network device that should remain in an active power state, wherein the first wireless network device and the second wireless network device are of a first plurality of wireless network devices in a first wireless network;

determining, by the first wireless network device, a first network identifier associated with the second wireless network device;

transmitting, by the first wireless network device, a first multicast message to the first plurality of wireless network devices, wherein the first multicast message comprises a header indicating the first network identifier, the first multicast message to cause the second wireless network device to remain in the active power state,

receiving, at the first wireless network device a first beacon frame via a second wireless network having a second plurality of wireless network devices;

determining, by the first wireless network device, whether the second wireless network;

determining, by the first wireless network device, a second network identifier associated with the first wireless network device based, at least in part, on network;

identifiers associated with the second plurality of wireless network devices;

transmitting, by the first wireless network device, a second beacon frame to the second plurality of wireless network devices, the second beacon frame comprising the second network identifier to indicate the first wireless network device has joined the second wireless network;

determining, by the first wireless network device, whether the first wireless network device will disconnect from the first wireless network;

transmitting, in a third beacon frame by the first wireless network device to a third wireless network device in the first wireless network, an indication that the first wireless network device has disconnected from the first wireless network if determined that the first wireless network device will disconnect from the first wireless network; and

transmitting, by the first wireless network device to the third wireless network device, the first network identifier in the third beacon frame if determined that the first wireless network device will remain connected to the first wireless network.

2. The method of claim 1, further comprising generating the first multicast message, wherein the generating comprises:

identifying a network identifier bit in a sequence field of the header of the first multicast message that corresponds to the first network identifier; and

setting the network identifier bit to a first value, wherein the first value indicates that the second wireless network device should remain in the active power state.

3. The method of claim 1, wherein

the header of the first multicast message comprises a first network identifier bit and a second network identifier bit,

the first network identifier bit corresponds to the first network identifier and has a first value to cause the second wireless network device to remain in the active power state,

the second network identifier bit corresponds to a third network identifier and is associated with a fourth wireless network device, and

the second network identifier bit includes a second value to cause the fourth wireless network device to enter an inactive power state.

4. The method of claim 1, wherein

the first wireless network comprises an ad-hoc wireless network,

the first multicast message is an announcement traffic indication map (ATIM) frame, and

the first plurality of wireless network devices are wireless local area network (WLAN) devices.

5. The method of claim 1, further comprising:

determining that a time-out interval has expired, wherein the time-out interval indicates a maximum time interval during which a fourth beacon frame is to be received from a fourth wireless network device;

determining the fourth beacon frame was not received from the fourth wireless network device before the time-out interval expired; and

updating a connection table associated with the first wireless network to indicate the fourth wireless network device has disconnected from the first wireless network.

6. The method of claim 1, further comprising:

receiving, at the second wireless network device, a second multicast message from a fourth wireless network device, the second multicast message including a network identifier bit that corresponds to the second network identifier;

determining whether the network identifier bit comprises a first value;

maintaining the active power state of the first wireless network device if the network identifier bit comprises the first value; and

changing the active power state of the first wireless network device to an inactive power state if the network identifier bit comprises a second value.

7. The method of claim 1, wherein said determining whether the first wireless network device should join the second wireless network comprises determining whether a number of the second plurality of wireless network devices in the second wireless network is equal to a maximum allowable number of wireless network devices in the second wireless network.

8. The method of claim 1, wherein said identifying the second wireless network device determining that the first second wireless network device has data to be transmitted to a fourth wireless network device.

9. A first wireless network device of a first plurality of wireless network devices in a first wireless network, the first wireless network device comprising:

a processor;

a network interface in communication with the processor; and

a connection management unit in communication with the processor and to the network interface, the connection management unit to;

identify a second wireless network device that should remain in an active power state, wherein the second wireless network device is of the first plurality of wireless network devices;

determine a first network identifier associated with the second wireless network device;

transmit a first multicast message to the first plurality of wireless network devices, wherein the first multicast message comprises a header indicating the first network identifier, the first multicast message to cause the second wireless network device to remain in the active power state;

receive a first beacon frame via a second wireless network having a second plurality of wireless network devices;

determine whether to join the second wireless network,

determine a second network identifier associated with the first wireless network device based, at least in part, on network identifiers associated with the second plurality of wireless network devices; and

transmit a second beacon frame to the second plurality of wireless network devices, the second beacon frame comprising the second network identifier to indicate the first wireless network device has joined the second wireless network;

wherein the connection management unit is to;

determine whether the first wireless network device will disconnect from the first wireless network;

transmit, to a third wireless network device in the first wireless network, in a third beacon frame an indication that the first wireless network device has disconnected from the first wireless network if determined that the first wireless network device will disconnect from the first wireless network; and

transmit, to the third wireless network device, the first network identifier in the third beacon frame if determined that that the first wireless network device will remain connected to the first wireless network.

10. The first wireless network device of claim 9, wherein the connection management unit to generate the first multicast message comprises the connection management unit to:

identify a network identifier bit in a sequence field of the header of the first multicast message that corresponds to the first network identifier associated with the second wireless network device; and

set the network identifier bit to a first value, wherein the first value indicates that the second wireless network device should remain in the active power state.

11. The first wireless network device of claim 9, wherein the header of the first multicast message comprises a first network identifier bit and a second network identifier bit,

the first network identifier bit corresponds to the first network identifier and has a first value to cause the second wireless network device to remain in the active power state,

a second network identifier bit corresponds to a third network identifier and is associated with a fourth wireless network device, and

the second network identifier bit includes a second value to cause the fourth wireless network device to enter an inactive power state.

12. The first wireless network device of claim 9, wherein the first wireless network comprises an ad-hoc wireless network, wherein the first multicast message is an announcement traffic indication map (ATIM) frame, and the first plurality of wireless network devices are wireless local area network (WLAN) devices, wherein the connection management unit is to:

determine that a time-out interval has expired, wherein the time-out interval indicates a maximum time interval during which a fourth beacon frame is to be received from a fourth wireless network device;

determine the fourth beacon frame was not received from the fourth wireless network device before the time-out interval expired; and

update a connection table associated with the ad-hoc wireless network to indicate the fourth wireless network device has disconnected from the ad-hoc wireless network.

13. The first wireless network device of claim 9, comprising a power management unit to:

receive a second multicast message from a fourth wireless network device, the second multicast message including a network identifier bit that corresponds to the second network identifier;

determine whether the network identifier bit comprises a first value;

maintain an active power state of the first wireless network device if the network identifier bit comprises the first value and

change the active power state of the first wireless network device to an inactive power state if the network identifier bit comprises a second value.

14. A non-transitory machine-readable storage medium, having instructions stored therein, which when executed by at least one processor of a first wireless network device causes the at least one processor to perform operations that comprise:

identifying a second wireless network device that should remain in an active power state, wherein the first wireless network device and the second wireless network device are of a first plurality of wireless network devices in a first wireless network;

determining a first network identifier associated with the second wireless network device;

transmitting a multicast message to the first plurality of wireless network devices, wherein the multicast message comprises a header indicating the first network identifier, the multicast message to cause the second wireless network device to remain in the active power state;

receiving a first beacon frame via a second wireless network having a second plurality of wireless network devices;

determining whether to join the second wireless network;

determining a second network identifier associated with the first wireless network device based, at least in part, on determining on network identifiers associated with the second plurality of wireless network devices;

transmitting a second beacon frame to the second plurality of wireless network devices the second beacon frame comprising the second network identifier to indicate the first wireless network device has joined the second wireless network;

determining whether the first wireless network device will disconnect from the first wireless network;

transmitting, to a third wireless network device in the first wireless network, in a third beacon frame an indication that the first wireless network device has disconnected from the first wireless network if determined that the first wireless network device will disconnect from the first wireless network; and

transmitting, to the third wireless network device, the first network identifier in the third beacon frame if determined that the first wireless network device will remain connected to the first wireless network.

15. The non-transitory machine-readable storage medium of claim 14,

wherein the instructions when executed by the at least one processor causes the at least one processor to perform further operations that comprise:

identifying a network identifier bit in a sequence field of the header of the multicast message that corresponds to the first network identifier; and

setting the network identifier bit to a first value, wherein the first value indicates that the first wireless network device should remain in the active power state.

16. The non-transitory machine-readable storage medium of claim 14, wherein the header of the multicast message comprises a first network identifier bit and a second network identifier bit, the first network identifier bit corresponds to the first network identifier and has a first value to cause the second wireless network device to remain in the active power state,

the second network identifier bit corresponds to a third network identifier and is associated with a fourth wireless network device, and

the second network identifier bit includes a second value to cause the fourth wireless network device to enter an inactive power state.

17. The non-transitory machine-readable storage medium of claim 14, wherein

the first wireless network comprises an ad-hoc wireless network,

the multicast message is an announcement traffic indication map (ATIM) frame, and

the first plurality of wireless network devices are wireless local area network (WLAN) devices.