ASYNCHRONOUS LOW-POWER MULTI-CHANNEL MEDIA ACCESS CONTROL

• US 20110176465A1
• Filed: 01/21/2010
• Published: 07/21/2011
• Est. Priority Date: 01/21/2010
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Panta, Rajesh Krishna, Tozlu, Serbulent, Keshavarzian, Abtin
• Granted Patent: US 8,588,119 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method for wirelessly transferring data between nodes may include periodically waking a receiving node from a sleep mode to a receive mode and returning the receiving node to the sleep mode, where, in the receive mode, the receiving node samples a plurality of wake-up channels; transmitting at least one wake-up preamble packet by a transmitting node on at least one of the plurality of wake-up channels; receiving, by the receiving node while in the receive mode, the wake-up preamble packet; transmitting, by the receiving node and responsive to receiving the wake-up preamble packet, an acknowledgement; transmitting, by the transmitting node and responsive to receiving the acknowledgement, a data frame on at least one data channel; and/or receiving, by the receiving node, the data frame. Some methods may include estimating a wake-up time of the receiving node and/or performing a clear channel assessment prior to transmitting the wake-up preamble packet.

Claims

1. A method for wirelessly transferring data between nodes, the method comprising:

periodically waking a receiving node from a sleep mode to a receive mode and returning the receiving node to the sleep mode, wherein, in the receive mode, the receiving node samples a plurality of wake-up channels;

transmitting at least one wake-up preamble packet by a transmitting node on at least one of the plurality of wake-up channels;

receiving, by the receiving node while in the receive mode, the wake-up preamble packet;

transmitting, by the receiving node and responsive to receiving the wake-up preamble packet, an acknowledgement;

transmitting, by the transmitting node and responsive to receiving the acknowledgement, a data frame on at least one data channel; and

receiving, by the receiving node, the data frame.

2. The method of claim 1,

wherein the at least one wake-up preamble packet includes a destination node identifier;

and

wherein transmitting the acknowledgement by the receiving node is responsive to the receiving node receiving the wake-up preamble packet and determining that the destination node identifier is associated with the receiving node.

3. The method of claim 1, wherein transmitting the at least one wake-up preamble packet by the transmitting node includes transmitting a plurality of wake-up preamble packets on one of the plurality of wake-up channels, individual wake-up preamble packets being spaced apart by a waiting time during which the transmitting node awaits receipt of the acknowledgement.

4. The method of claim 3, wherein transmitting, by the transmitting node and responsive to receiving the acknowledgement, the data frame includes stopping transmitting the plurality of wake-up preamble packets responsive to receiving the acknowledgement.

5. The method of claim 1, wherein the at least one data channel is different than any of the plurality of wake-up channels.

6. The method of claim 1, wherein transmitting the at least one wake-up preamble packet by the transmitting node includes estimating a time when the receiving node will awake from the sleep mode to the receive mode and transmitting the at least one wake-up preamble packet to be received by the receiving node while the receiving node is in the receive mode.

7. The method of claim 1,

wherein the wake-up preamble packet includes an indication of a number of data frames that are to be transferred, the number being greater than one;

wherein transmitting, by the transmitting node and responsive to receiving the acknowledgement, the data frame includes transmitting the number of data frames; and

wherein receiving, by the receiving node, the data frame includes receiving the number of data frames.

8. The method of claim 1, further comprising, before transmitting the at least one wake-up preamble packet, performing a clear channel assessment on the at least one wake-up channel.

9. A method for wirelessly transferring data between nodes, the method comprising:

periodically waking a receiving node from a sleep mode to a receive mode and returning the receiving node to the sleep mode;

calculating an estimated wake-up time at which the receiving node will wake from the sleep mode to the receive mode; and

transmitting at least one packet by a transmitting node at about the estimated wake-up time.

10. The method of claim 9, wherein calculating the estimated wake-up time includes considering at least a previous wake-up time of the receiving node and a sleep period duration associated with the receiving node.

11. The method of claim 10, further comprising, if the receiving node does not receive the packet, periodically re-transmitting the packet until the receiving node receives the packet.

12. The method of claim 11, further comprising storing a time when the transmitting node most recently successfully sent a packet to the receiving node.

13. The method of claim 12, further comprising calculating a future estimated wake-up time based at least in part upon the stored time when the transmitting node most recently successfully sent a packet to the receiving node.

14. The method of claim 9, further comprising, before transmitting the at least one packet, performing a clear channel assessment on a channel on which the packet will be transmitted.

15. The method of claim 9,

wherein, in the receive mode, the receiving node samples a plurality of channels;

and

wherein transmitting the at least one packet includes transmitting the at least one packet on one of the plurality of channels.

16. A method for wirelessly transferring data between nodes, the method comprising:

periodically waking a receiving node from a sleep mode to a receive mode and returning the receiving node to the sleep mode, wherein, in the receive mode, the receiving node samples at least one wake-up channel;

performing a clear channel assessment on the wake-up channel;

transmitting at least one wake-up preamble packet by a transmitting node on the wake-up channel upon determining that the wake-up channel is clear;

receiving, by the receiving node while in the receive mode, the wake-up preamble packet;

transmitting, by the receiving node and responsive to receiving the wake-up preamble packet, an acknowledgement;

transmitting, by the transmitting node and responsive to receiving the acknowledgement, a data frame on a data channel; and

receiving, by the receiving node, the data frame.

17. The method of claim 16,

wherein performing the clear channel assessment includes sampling the wake-up channel for a clear channel assessment time determined at least from a wait time plus a substantially random additional delay;

and

wherein the wait time corresponds to a time between transmission of consecutive wake-up preamble packets when the transmitting node does not receive the acknowledgement.

18. The method of claim 16,

further comprising, before transmitting the at least one wake-up preamble packet, calculating an estimated wake-up time at which the receiving node will wake from the sleep mode to the receive mode;

and

wherein transmitting the at least one wake-up preamble packet includes transmitting the at least one wake-up preamble packet at about the estimated wake-up time.

19. The method of claim 18, wherein transmitting the at least one wake-up preamble packet includes periodically re-transmitting the at least one wake-up preamble packet until the transmitting node receives the acknowledgement.

20. The method of claim 16,

wherein, in the receive mode, the receiving node samples a plurality of wake-up channels;

and

further comprising, before performing a clear channel assessment, selecting one wake-up channel from among the plurality of wake-up channels.