METHOD AND SYSTEM FOR BROADCAST MESSAGE TRANSMISSION IN MOBILE SYSTEMS

• US 20100267344A1
• Filed: 06/28/2010
• Published: 10/21/2010
• 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, Güner, Refi-Tugrul
• Granted Patent: US 8,265,624 B2
• Time in Patent Office: Days
• US Class Current: 455/67.110
• 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
• CPC Class Codes: H04W 52/322 Power control of broadcast channels
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 72/51 based on terminal or device properties
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A method and device for dynamically changing transmission parameters of broadcast messages transmitted and received by a mobile unit. The method and device include monitoring transmission channel characteristics; dynamically adjusting the transmission parameters of a message based on the monitored transmission channel characteristics; and broadcasting the message using the adjusted transmission parameters. The transmission parameters may include one or more of transmission power, error code rate, and modulation rate. The transmission channel characteristics include one or more of the group consisting of received message density, channel congestion, detected number of message collisions, and signal to interference ratio.

Claims

1. A method for dynamically changing transmission parameters of broadcast messages transmitted by a mobile unit, the method comprising:

monitoring transmission channel characteristics;

dynamically adjusting the transmission parameters of a message based on the monitored transmission channel characteristics; and

broadcasting the message using the adjusted transmission parameters.

2. The method of claim 1, wherein the transmission parameters include one or more of the group consisting of transmission power, error code rate, and modulation rate.

3. The method of claim 1, wherein the transmission channel characteristics include one or more of the group consisting of received message density, channel congestion, detected number of message collisions, and link quality.

4. The method of claim 1, further comprising adjusting a transmission rate of the message based on the monitored transmission channel characteristics.

5. The method of claim 1, further comprising monitoring speed of the mobile unit;

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

6. The method of claim 5, wherein 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.

7. The method of claim 1, wherein high-priority messages are broadcast more robustly than low priority messages.

8. The method of claim 1, wherein the transmission channel characteristics include one or more of the group consisting number of messages, number of transmitters, received signal level, received signal quality, received signal code rate, received signal modulation rate, channel congestion per time unit, and channel congestion per space unit.

9. The method of claim 1, wherein dynamically adjusting the transmission parameters comprises increasing a transmission robustness when less messages are received in a given timeframe, and decreasing the transmission robustness when more messages are received in the given timeframe.

10. The method of claim 1, wherein monitoring transmission channel characteristics comprises monitoring transmission channel characteristics without polling the mobile unit.

11. The method of claim 4, further comprising determining a transmission channel loading based on the number of transmission collisions detected in the transmission channel in a given time interval;

lowering the transmission rate when the transmission channel loading is heavy; and

increasing the transmission rate when the transmission channel loading is light.

20. The mobile device of claim 1, wherein the processor dynamically adjusts the transmission parameters by increasing a transmission robustness when less messages are received in a given timeframe, and decreasing the transmission robustness when more messages are received in the given timeframe.

12. A mobile device for wirelessly communicating broadcast messages at a transmission rate comprising:

a radio transceiver for receiving and transmitting the broadcast messages;

a processor for monitoring transmission channel characteristics, dynamically adjusting the transmission parameters of a message based on the monitored transmission channel characteristics; and

transmitting the message using the adjusted transmission parameters.

13. The mobile device of claim 12, wherein the transmission parameters include one or more of the group consisting of transmission power, error code rate, and modulation rate.

14. The mobile device of claim 12, wherein the transmission channel characteristics include one or more of the group consisting of received message density, channel congestion, detected number of message collisions, and link quality.

15. The mobile device of claim 12, wherein the processor further adjusts a transmission rate of the message based on the monitored transmission channel characteristics.

16. The mobile device of claim 12, wherein the processor further monitors speed of the mobile device;

and adjusts transmission rate of the message based on the speed of the mobile device.

17. The mobile device of claim 16, wherein the processor decreases the transmission rate when the speed of the mobile device is reduced, and increases the transmission rate when the speed of the mobile device is increased.

18. The mobile device of claim 12, wherein high-priority messages are broadcast more robustly than low priority messages.

19. The mobile device of claim 12, wherein the transmission channel characteristics include one or more of the group consisting number of messages, number of transmitters, received signal level, received signal quality, received signal code rate, received signal modulation rate, channel congestion per time unit, and channel congestion per space unit.