System and method for adjusting power used in reception in a wireless packet network

• US 9,094,916 B1
• Filed: 04/09/2012
• Issued: 07/28/2015
• Est. Priority Date: 04/25/2006
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Hui, Jonathan W., Culler, David E.
• Primary Examiner(s): Shivers, Ashley
• Application Number:
  US13/442,408
• Time in Patent Office: 1,205 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04L 12/00 Data switching networks interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units G06F13/00
• CPC Class Codes: H04W 52/0248 dependent on the time of the day, e.g. according to expected transmission activity
• CPC Class Codes: H04W 52/0258 controlling an operation mode according to history or models of usage information, e.g. activity schedule or time of day
• CPC Class Codes: H04W 52/0261 managing power supply demand, e.g. depending on battery level
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A system and method allows devices to send and receive packets while using power to do so in a manner that responds to events, such as receipt or other identification of different parameters that control how packets are sent and received.

Claims

1. A method comprising:

receiving, at a receiver node, a chirp packet transmitted by a source node;

examining, by the receiver node, information included in the chirp packet;

based on information included in the chirp packet, turning on, by the receiver node, a radio associated with the receiver node at a time indicated by the information included in the chirp packet for transmission of a data packet by the source node;

monitoring, by the receiver node and using the radio, the channel for reception of other data packets for a time period that is longer than an expected length of time that is indicated by the information included in the chirp packet for transmission of the data packet; and

receiving, by the receiver node, another data packet that is transmitted by another source node at a time during the time period after expiry of the expected length of time for transmission of the data packet by the source node, the another data packet being transmitted without a chirp packet.

2. The method of claim 1, wherein the time period for monitoring the channel is configured to be longer than a maximum back off period following reception of the another data packet, such that other data packets that may have been transmitted by other sources may be received.

3. The method of claim 1, further comprising:

receiving, at a source node, packets for transmission in a communications network, the packets including a chirp packet that indicates a later instant in time when a data packet will be transmitted by the source node;

buffering, by the source node, the packets till at least one measurable quantity meets a predetermined threshold, at which time transmission is performed;

determining, by the source node, whether at least one measurable quantity has achieved the predetermined threshold; and

based on determining that at least one measurable quantity has achieved the predetermined threshold, transmitting, by the source node and over a channel in the communications network, the packets.

4. The method of claim 3, wherein the at least one measurable quantity is:

one or more of an amount of time since a first packet was received, a number of data elements received for transmission, or

an amount of data received for transmission.

5. The method of claim 3, comprising:

determining, by the source node, whether the receiver node that is intended as a recipient for the packets is a power-constrained device; and

based on determining that the receiver node is a power-constrained device, decreasing, by the source node, a number of the packets that are transmitted based on at least one of;

increasing a value of the predetermined threshold such that a time associated with buffering the packets is increased,

increasing a length of a chirp period that corresponds to a time interval during which the packets are transmitted, and

decreasing a frequency at which the packets are transmitted.

6. The method of claim 5, wherein a power-constrained device includes a network node that is operating on battery power or other portable power.

7. The method of claim 5, comprising:

identifying, by at least one of the source node and the receiver node, parameters corresponding to transmission or reception of communications between the source node and the receiver node, the parameters including at least one of;

a sleep period that indicates a time interval during which the source node and the receiver node are to awaken at least once to listen for a chirp packet on the channel or to measure a level of energy on the channel, wherein the sleep period of the receiver node is set to a value that is not greater than a minimum chirp period associated with the source node,

the chirp period,

a chirp interval that indicates a total amount of time for which a chirp packet is transmitted, including a downtime between transmitting chirp packets, wherein the source node is configured to operate in a reduced power mode between chirp intervals,

a listening window that indicates a time interval during which a radio of the receiver node is configured to be on such that a chirp packet transmitted by the source node is received, and

channel information that includes at least one of a frequency channel and a logical channel over which the source node transmits packets to the receiver node.

8. The method of claim 7, wherein information included in a chirp packet comprises at least one of:

a chirp packet pattern that includes a recognizable pattern of bits in a predetermined portion of the chirp packet and configured to identify the chirp packet,

a time to data packet that includes bits in the chirp packet indicating a time interval starting from a time associated with a predetermined section of the chirp packet, after expiry of which a data packet will be transmitted,

an expected length of time for transmission of the data packet following the chirp packet,

a number of data packets to be transmitted following transmission of chirp packets, and

information associated with the parameters corresponding to transmission or reception of communications between the source node and the receiver node.

9. A system comprising:

a source node including first instructions that are encoded in a non-transitory computer-readable first medium for execution by a first processor and configured to cause the first processor to perform operations comprising;

receiving, by the source node, packets for transmission to a receiver node in a communications network, the packets including a chirp packet indicating a later instant in time when a data packet will be transmitted by the source node;

buffering, by the source node, the packets till at least one measurable quantity meets a predetermined threshold, at which time transmission is performed;

determining, by the source node, whether at least one measurable quantity has achieved the predetermined threshold; and

based on determining that at least one measurable quantity has achieved the predetermined threshold, transmitting, by the source node and over a channel in the communications network, the packets; and

a receiver node including second instructions that are encoded in a non-transitory computer-readable second medium for execution by a second processor and configured to cause the second processor to perform operations comprising;

receiving, at the receiver node, the chirp packet transmitted by the source node;

examining, by the receiver node, information included in the chirp packet;

based on information included in the chirp packet, turning on, by the receiver node, a radio associated with the receiver node at a time indicated by the information included in the chirp packet for transmission of a data packet by the source node;

monitoring, by the receiver node and using the radio, the channel for reception of other data packets for a time period that is longer than an expected length of time that is indicated by the information included in the chirp packet for transmission of the data packet; and

receiving, by the receiver node, another data packet that is transmitted by another source node at a time during the time period after expiry of the expected length of time for transmission of the data packet by the source node, the another data packet being transmitted without a chirp packet.

10. The system of claim 9, wherein the at least one measurable quantity is selected from a group comprising:

one or more of an amount of time since a first packet was received, a number of data elements received for transmission, and

an amount of data received for transmission.

11. The system of claim 9, wherein the first instructions are configured to cause the first processor to perform operations comprising:

determining, by the source node, whether the receiver node is a power-constrained device; and

based on determining that the receiver node is a power-constrained device, decreasing, by the source node, a number of the packets that are transmitted based on at least one of;

increasing a value of the predetermined threshold such that a time associated with buffering the packets is increased,

increasing a length of a chirp period that corresponds to a time interval during which the packets are transmitted, and

decreasing a frequency at which the packets are transmitted.

12. The system of claim 11, wherein a power-constrained device includes a network node that is operating on battery power or other portable power.

13. The system of claim 11, wherein the first instructions and the second instructions include instructions that are configured to cause the respective first processor and the second processor to perform operations comprising:

identifying, by at least one of the source node and the receiver node, parameters corresponding to transmission or reception of communications between the source node and the receiver node, the parameters including at least one of;

a sleep period that indicates a time interval during which the source node and the receiver node are to awaken at least once to listen for a chirp packet on the channel or to measure a level of energy on the channel, wherein the sleep period of the receiver node is_set to a value that is not greater than a minimum chirp period associated with the source node,

the chirp period,

a chirp interval that indicates a total amount of time for which a chirp packet is transmitted, including a downtime between transmitting chirp packets, wherein the source node is configured to operate in a reduced power mode between chirp intervals,

a listening window that indicates a time interval during which a radio of the receiver node is configured to be on such that a chirp packet transmitted by the source node is received, and

channel information that includes at least one of a frequency channel and a logical channel over which the source node transmits packets to the receiver node.

14. The system of claim 13, wherein information included in a chirp packet comprises at least one of:

a chirp packet pattern that includes a recognizable pattern of bits in a predetermined portion of the chirp packet and configured to identify the chirp packet,

a time to data packet that includes bits in the chirp packet indicating a time interval starting from a time associated with a predetermined section of the chirp packet, after expiry of which a data packet will be transmitted,

an expected length of time for transmission of the data packet following the chirp packet,

a number of data packets to be transmitted following transmission of chirp packets, and

information associated with the parameters corresponding to transmission or reception of communications between the source node and the receiver node.

15. The system of claim 9, wherein the time period for monitoring the channel is configured to be longer than a maximum back off period following reception of the another data packet, such that other data packets that may have been transmitted by other sources may be received.

16. A computer program product, embodied in a non-transitory computer-readable medium storing software comprising instructions executable by one or more computers, which, upon such execution, cause the one or more computers to perform operations comprising:

receiving, at a receiver node in a communications network, a chirp packet transmitted by a source node, the chirp packet indicating a later instant in time when a data packet will be transmitted by the source node;

examining, by the receiver node, information included in the chirp packet;

based on information included in the chirp packet, turning on, by the receiver node, a radio associated with the receiver node at a time indicated by the information included in the chirp packet for transmission of the data packet by the source node;

monitoring, by the receiver node and using the radio, the channel for reception of other data packets for a time period that is longer than an expected length of time that is indicated by the information included in the chirp packet for transmission of the data packet; and

receiving, by the receiver node, another data packet that is transmitted by another source node at a time during the time period after expiry of the expected length of time for transmission of the data packet by the source node, the another data packet being transmitted without a chirp packet.

17. The computer program product of claim 16, wherein the time period for monitoring the channel is configured to be longer than a maximum back off period following reception of the another data packet, such that other data packets that may have been transmitted by other sources may be received.

18. The computer program product of claim 16, further comprising:

receiving, at a source node, packets for transmission in a communications network, the packets including a chirp packet that indicates a later instant in time when a data packet will be transmitted by the source node;

buffering, by the source node, the packets till at least one measurable quantity meets a predetermined threshold, at which time transmission is performed;

determining, by the source node, whether at least one measurable quantity has achieved the predetermined threshold; and

based on determining that at least one measurable quantity has achieved the predetermined threshold, transmitting, by the source node and over a channel in the communications network, the packets.

19. The computer program product of claim 18, wherein the at least one measurable quantity is:

one or more of an amount of time since a first packet was received, a number of data elements received for transmission, or

an amount of data received for transmission.

20. The computer program product of claim 18, wherein the instructions cause the one or more computers to perform operations comprising:

determining, by the source node, whether the receiver node that is intended as a recipient for the packets is a power-constrained device; and

based on determining that the receiver node is a power-constrained device, decreasing, by the source node, a number of the packets that are transmitted based on at least one of;

increasing a value of the predetermined threshold such that a time associated with buffering the packets is increased,

increasing a length of a chirp period that corresponds to a time interval during which the packets are transmitted, and

decreasing a frequency at which the packets are transmitted.

21. The computer program product of claim 20, wherein a power-constrained device includes a network node that is operating on battery power or other portable power.

22. The computer program product of claim 18, wherein the instructions cause the one or more computers to perform operations comprising:

identifying, by the source node, parameters corresponding to transmission or reception of communications between the source node and the receiver node, the parameters including at least one of;

a sleep period that indicates a time interval during which the source node and the receiver node are to awaken at least once to listen for a chirp packet on the channel or to measure a level of energy on the channel, wherein the sleep period of the receiver node is set to a value that is not greater than a minimum chirp period associated with the source node,

the chirp period,

a chirp interval that indicates a total amount of time for which a chirp packet is transmitted, including a downtime between transmitting chirp packets, wherein the source node is configured to operate in a reduced power mode between chirp intervals,

a listening window that indicates a time interval during which a radio of the receiver node is configured to be on such that a chirp packet transmitted by the source node is received, and

channel information that includes at least one of a frequency channel and a logical channel over which the source node transmits packets to the receiver node.

23. The computer program product of claim 18, wherein information included in a chirp packet comprises at least one of:

a chirp packet pattern that includes a recognizable pattern of bits in a predetermined portion of the chirp packet and configured to identify the chirp packet,

a time to data packet that includes bits in the chirp packet indicating a time interval starting from a time associated with a predetermined section of the chirp packet, after expiry of which a data packet will be transmitted,

an expected length of time for transmission of the data packet following the chirp packet,

a number of data packets to be transmitted following transmission of chirp packets, and

information associated with the parameters corresponding to transmission or reception of communications between the source node and the receiver node.