METHOD AND SYSTEM FOR BROADCAST MESSAGE RATE ADAPTATION IN MOBILE SYSTEMS

• US 20090081958A1
• Filed: 09/24/2007
• Published: 03/26/2009
• Est. Priority Date: 09/24/2007
• Status: Active Grant

• Current Assignee: Kapsch TrafficCom AG (Datax Handelsgmbh)
• Original Assignee: Kapsch TrafficCom AG (Datax Handelsgmbh)
• Inventors: McNew, Justin Paul, Dessouky, Khaled I., Moring, John Thomas
• Granted Patent: US 8,509,764 B2
• Time in Patent Office: Days
• US Class Current: 455/69
• CPC Class Codes: G08G 1/163 involving continuous checking
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04B 17/382 for resource allocation, admission control or handover

Abstract

A method and system for setting transmission rate of messages transmitted and received by a mobile unit. The method and system include monitoring the speed of the mobile unit; and adjusting the transmission rate based on the speed of the mobile unit. Prevailing conditions may also be determined and the transmission rate may be further adjusted based on the prevailing conditions. The prevailing conditions may be determined based on at least one of states of one or more sensors local to the mobile unit and information provided from an external source over a communication system. The prevailing conditions may include at least one of slick pavement, limited visibility, road construction, object in roadway, accident, dense traffic, and anomalous driving behavior.

Claims

1. A method for setting transmission rate of messages transmitted and received by a mobile unit, the method comprising:

monitoring speed of the mobile unit; and

adjusting the transmission rate based on the speed of the mobile unit.

2. The method of claim 1, where the transmission rate is adjusted such that the transmission rate is decreased when the speed of the mobile unit is reduced, and the transmission rate is increased when the speed of the mobile unit is increased.

3. The method of claim 1, further comprising

determining prevailing conditions;

and

adjusting the transmission rate based on the prevailing conditions.

4. The method of claim 3, wherein the prevailing conditions are determined based on at least one of states of one or more sensors local to the mobile unit and information provided from an external source over a communication system.

5. The method of claim 3, wherein the prevailing conditions include at least one of slick pavement, limited visibility, road construction, object in roadway, accident, dense traffic, and anomalous driving behavior.

6. The method of claim 1, wherein the transmission rate is further lowered when transmission channel loading is heavy and the transmission rate is increased when the transmission channel loading is light.

7. The method of claim 6, further comprising determining the transmission channel loading based on number of messages received in a given time interval.

8. The method of claim 6, further comprising determining the transmission channel loading based on average radio energy received in a given time interval.

9. The method of claim 6, further comprising determining the transmission channel loading based on the number of transmission collisions detected in the transmission channel in a given time interval.

10. The method of claim 5, further comprising determining the transmission channel loading based on the proportion of time the transmission channel is in a busy or idle state in a given time interval.

11. The method of claim 5, further comprising receiving a value for the transmission channel loading over a communication network.

12. The method of claim 1, wherein adjusting the transmission rate includes at least one of a minimum transmission rate and a maximum transmission rate.

13. The method of claim 1, wherein the transmission rate is further adjusted based on rate of change of a velocity vector of the mobile unit.

14. The method of claim 1, where the messages are basic safety messages.

15. A mobile device for communicating messages at a transmission rate comprising:

a radio transceiver for receiving and transmitting the messages;

a processor for monitoring speed of the mobile unit and adjusting the transmission rate based on the speed of the mobile unit.

16. The mobile device of claim 15, wherein the processor adjusts the transmission rate such that the transmission rate is decreased when the speed of the mobile unit is reduced, and the transmission rate is increased when the speed of the mobile unit is increased.

17. The mobile device of claim 15, wherein the processor further determines prevailing conditions and adjusts the transmission rate based on the prevailing conditions.

18. The mobile device of claim 17, wherein the processor determines the prevailing conditions based on at least one of states of one or more sensors local to the mobile unit and information provided from an external source over a communication system.

19. The mobile device of claim 15, wherein the processor further determines transmission channel loading and adjusts the transmission rate based on the transmission channel loading.

20. The mobile device of claim 19, wherein the processor determines transmission channel loading based on number of messages received in a given time interval.

21. The mobile device of claim 19, wherein the processor determines transmission channel loading based on a value received from a stationary unit over a communication system.