Dynamic adjustment of wireless communication transmission rates

• US 9,532,194 B2
• Filed: 05/09/2014
• Issued: 12/27/2016
• Est. Priority Date: 05/09/2014
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Zhang, Tao, Antunes, Helder, Patel, Chintan, Alam, Mahbubul
• Primary Examiner(s): Gonzalez, Amancio
• Application Number:
  US14/273,948
• Publication Number:
  US 20150327028A1
• Time in Patent Office: 963 Days
• Field of Search: 455/452.1
• US Class Current: 1/1
• CPC Class Codes: G08G 1/163 involving continuous checking
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 4/12 Messaging; Mailboxes; Announcements
• CPC Class Codes: H04W 4/46 for vehicle-to-vehicle communication [V2V]
• CPC Class Codes: H04W 64/006 with additional information processing, e.g. for direction or speed determination

Abstract

Apparatus, methods and logic for vehicles to determine vehicle to vehicle (V2V) safety message transmission rates for transmitting V2V safety messages based on how frequently the vehicles actually need to exchange safety messages, including factors such as vehicle velocities, distances among vehicles, and on how quickly the inter-vehicle distances are closing up. The determined V2V safety message transmission rates are selectively dynamically adjusted in accordance with detected significant changes in one or more of the inter-vehicle distances or inter-vehicle speeds. To avoid needless frequent changes to the transmission rate, statistical modeling techniques including hypothesis testing and sequential change detection are selectively used to more accurately detect significant changes in inter-vehicle distances or inter-vehicle speeds that warrant a change to the message transmission rate.

Claims

1. An apparatus comprising:

a wireless transmitter configured to transmit a first signal comprising a safety message related to an associated first vehicle;

a non-transient memory storing first operational data describing motion of the first vehicle, wherein the first operational data comprises one or more of a first speed of the first vehicle, a first position of the first vehicle, and a first driving direction of the first vehicle;

a wireless receiver configured to receive a second signal from an associated second vehicle, wherein the second signal comprises second operational data describing motion of the second vehicle, wherein the second operational data comprises one or more of first speed data representative of a second speed of the second vehicle, first position data representative of a second position of the second vehicle, and first driving direction data representative of a second driving direction of the second vehicle; and

transmission rate control logic operatively coupled with the memory, the wireless transmitter, and the wireless receiver, the transmission rate control logic configured to determine, based on the first and second operational data, a first message transmission rate for transmitting the first signal by the wireless transmitter.

2. The apparatus according to claim 1, wherein:

the wireless transmitter transmits the first signal at the first message transmission rate determined by the transmission rate control logic.

3. The apparatus according to claim 2, wherein:

the wireless receiver is further configured to receive a third signal from the second vehicle, the third signal comprising third operational data describing motion of the second vehicle, the third operational data comprising one or more of second speed data representative of a third speed of the second vehicle, second position data representative of a third position of the second vehicle, and second driving direction data representative of a third driving direction of the second vehicle;

the non-transient memory stores fourth operational data comprising one or more of a fourth speed of the first vehicle, a fourth position of the first vehicle, and a fourth driving direction of the first vehicle;

the transmission rate control logic is further configured to dynamically adjust the first message transmission rate to a second message transmission rate determined based on the third and fourth operational data; and

the wireless transmitter transmits a subsequent signal comprising a subsequent safety message at the second message transmission rate determined by the transmission rate control logic.

4. The apparatus according to claim 2, wherein the transmission rate control logic is further configured to:

determine a first relative distance between the first vehicle and the second vehicle based on a comparison between the first operational data and the second operational data;

determine a first relative speed between the first vehicle and the second vehicle based on a comparison between the first operational data and the second operational data; and

determine the first message transmission rate based on a statistical processing of the first operational data and at least one of the determined first relative distance and the determined first relative speed.

5. The apparatus according to claim 4, wherein:

the wireless receiver is further configured to receive a third signal from the second vehicle, the third signal comprising third operational data describing motion of the second vehicle, the third operational data comprising one or more of second speed data representative of a third speed of the second vehicle, second position data representative of a third position of the second vehicle, and second driving direction data representative of a third driving direction of the second vehicle;

the non-transient memory stores fourth operational data comprising one or more of a fourth speed of the first vehicle, a fourth position of the first vehicle, and a fourth driving direction of the first vehicle;

the transmission rate control logic is further configured to;

determine a second relative distance between the first vehicle and the second vehicle based on a comparison between the third and fourth operational data;

a second relative speed between the first vehicle and the second vehicle based on a comparison between the third and fourth operational data; and

determine the second message transmission rate based on a statistical processing of the second operational data and at least one of the determined second relative distance and the determined second relative speed; and

the wireless transmitter transmits a subsequent signal comprising a subsequent safety message at the determined second message transmission rate.

6. The apparatus according to claim 5, wherein the transmission rate control logic is further configured to:

determine a first change in relative distance between the first vehicle and the second vehicle based on a comparison between the determined first and second relative distances;

determine a first change in relative speed between the first vehicle and the second vehicle based on a comparison between the determined first and second relative speeds; and

determine the second message transmission rate based on a statistical processing of the determined first change in relative distance and the determined first change in relative speed.

7. The apparatus according to claim 6, wherein the statistical processing of the determined first change in relative distance and the determined first change in relative speed comprises one or more of a hypothesis testing processing or a sequential change detection processing.

8. A method comprising:

storing first operational data in a non-transient memory, the first operational data describing motion of the first vehicle and comprising one or more of a first speed of the first vehicle, a first position of the first vehicle, and a first driving direction of the first vehicle;

receiving, from a second vehicle and using a wireless receiver, a third signal comprising second operational data, the second operational data describing motion of the second vehicle and comprising one or more of first speed data representative of a second speed of the second vehicle, first position data representative of a second position of the second vehicle, and first driving direction data representative of a second driving direction of the second vehicle;

determining a first message transmission rate for transmitting a first vehicle-to-vehicle (V2V) safety message from the first vehicle to the second vehicle based on the first operational data and the second operational data, wherein the first message transmission rate is determined using transmission rate control logic operatively coupled with the memory, a wireless transmitter, and the wireless receiver, the first message transmission rate determined based on the first operational data and the second operational data;

transmitting, using the wireless transmitter, a first signal comprising the first V2V safety message from the first vehicle at the first message transmission rate;

determining a second message transmission rate for transmitting a second V2V safety message from the first vehicle to the second vehicle based on a statistical processing of a change in the first operational data during a first time period and a change in the second operational data during the first time period; and

transmitting, using the wireless transmitter, a second signal comprising the second V2V safety message from the first vehicle at the second message transmission rate.

9. The method according to claim 8, further comprising:

receiving, from the second vehicle and using the wireless receiver, a fourth signal comprising third operational data describing motion of the second vehicle, wherein the third operational data comprises one or more of second speed data representative of a third speed of the second vehicle, second position data representative of a third position of the second vehicle, and second driving direction data representative of a third driving direction of the second vehicle;

storing fourth operational data describing motion of the first vehicle in the non-transient memory, the fourth operational data comprising one or more of a fourth speed of the first vehicle, a fourth position of the first vehicle, and a fourth driving direction of the first vehicle; and

dynamically adjusting, using the transmission rate control logic, the first message transmission rate to the second message transmission rate determined based on the third and fourth operational data.

10. The method according to claim 8, further comprising:

determining, using the transmission rate control logic, a first relative distance between the first vehicle and the second vehicle based on a comparison between the first operational data and the second operational data;

determining, using the transmission rate control logic, a first relative speed between the first vehicle and the second vehicle based on a comparison between the first operational data and the second operational data; and

wherein the first message transmission rate is determined based on a statistical processing of the first operational data and at least one of the determined first relative distance and the determined first relative speed.

11. The method according to claim 10, further comprising:

receiving, from the second vehicle and using the wireless receiver, a fourth signal comprising third operational data describing motion of the second vehicle, wherein the third operational data comprises one or more of second speed data representative of a third speed of the second vehicle, second position data representative of a third position of the second vehicle, and second driving direction data representative of a third driving direction of the second vehicle;

storing fourth operational data describing motion of the first vehicle in the non-transient memory, the fourth operational data comprising one or more of a fourth speed of the first vehicle, a fourth position of the first vehicle, and a fourth driving direction of the first vehicle;

determining, using the transmission rate control logic, a second relative distance between the first vehicle and the second vehicle based on a comparison between the third and fourth operational data; and

determining, using the transmission rate control logic, a second relative speed between the first vehicle and the second vehicle based on a comparison between the third and fourth operational data,

wherein the second message transmission rate is determined based on a statistical processing of the second operational data and at least one of the determined second relative distance and the determined second relative speed.

12. The method according to claim 11, further comprising:

determining, using the transmission rate control logic, a first change in relative distance between the first vehicle and the second vehicle based on a comparison between the determined first and second relative distances; and

determining, using by the transmission rate control logic, a first change in relative speed between the first vehicle and the second vehicle based on a comparison between the determined first and second relative speeds,

wherein the second message transmission rate is determined based on a statistical processing of the determined first change in relative distance and the determined first change in relative speed.

13. The method according to claim 12,

wherein the statistical processing of the determined first change in relative distance and the determined first change in relative speed comprises one or more of a hypothesis testing processing or a sequential change detection processing.

14. Logic encoded in one or more tangible non-transient computer readable media for execution by an associated processor and when executed by the associated processor the logic being operable to:

transmit, using a wireless transmitter coupled with the logic, a first signal comprising a safety message related to a first vehicle;

store, in a non-transient memory coupled with the logic, first operational data describing motion of the first vehicle, the first operational data comprising one or more of a first speed, a first position, and a first driving direction of the first vehicle;

receive, from a second vehicle and using a wireless receiver coupled with the logic, a second signal comprising second operational data describing motion of the second vehicle, wherein the second operational data comprises one or more of first speed data representative of a second speed of the second vehicle, first position data representative of a second position of the second vehicle, and first driving direction data representative of a second driving direction of the second vehicle;

determine a first message transmission rate for transmitting the first signal based on the first operational data and the second operational data;

transmit, using the wireless transmitter, the first signal at the determined first message transmission rate;

receive, from the second vehicle and using the wireless receiver, a third signal comprising third operational data describing motion of the second vehicle, wherein the third operational data comprises one or more of second speed data representative of a third speed of the second vehicle, second position data representative of a third position of the second vehicle, and second driving direction data representative of a third driving direction of the second vehicle;

store, in the non-transient memory, fourth operational data describing motion of the first vehicle, the fourth operational data comprising one or more of a fourth speed, a fourth position, and a fourth driving direction of the first vehicle;

dynamically adjust the first message transmission rate to a second message transmission rate based on a comparison between the third and fourth operational data; and

transmit, using the wireless transmitter, a fourth signal comprising a subsequent safety message at the determined second message transmission rate.

15. The logic according to claim 14, further operable to:

determine a first relative distance between the first vehicle and the second vehicle based on a comparison between the first operational data and the second operational data;

determine a first relative speed between the first vehicle and the second vehicle based on a comparison between the first operational data and the second operational data; and

determine the first message transmission rate based on a statistical processing of the first operational data and at least one of the determined first relative distance and the determined first relative speed.

16. The logic according to claim 15, further operable to:

receive, from the second vehicle and using the wireless receiver, a third signal comprising third operational data describing motion of the second vehicle, wherein the third operational data comprises one or more of second speed data representative of a third speed of the second vehicle, second position data representative of a third position of the second vehicle, and second driving direction data representative a third driving direction of the second vehicle;

store, in the non-transient memory, fourth operational data describing motion of the first vehicle, the fourth operational data comprising one or more of a fourth speed, a fourth position, and a fourth driving direction of the first vehicle;

determine a second relative distance between the first vehicle and the second vehicle based on a comparison between the third operational data and the fourth operational data;

determine a second relative speed between the first vehicle and the second vehicle based on a comparison between the third operational data and the fourth operational data;

determine a second message transmission rate based on a statistical processing of the second operational data and one or more of the determined second relative distance and the determined second relative speed; and

transmit, using the wireless transmitter, a fourth signal comprising a subsequent safety message at the determined second message transmission rate.

17. The logic according to claim 16, further operable to:

determine a first change in relative distance between the first vehicle and the second vehicle based on a comparison between the determined first and second relative distances;

determine a first change in relative speed between the first vehicle and the second vehicle based on a comparison between the determined first and second relative speeds; and

determine the second message transmission rate based on a statistical processing of the determined first change in relative distance and the determined first change in relative speed.

18. The logic according to claim 17,

wherein the statistical processing of the determined first change in relative distance and the determined first change in relative speed comprises one or more of a hypothesis testing processing or a sequential change detection processing.