METHOD FOR REDUCING LATENCY OF WIRELESS DATA PACKET DELIVERY

• US 20090323716A1
• Filed: 04/22/2009
• Published: 12/31/2009
• Est. Priority Date: 04/22/2008
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Chintalapudi, Krishna Kant, Venkatraman, Lakshmi
• Granted Patent: US 9,113,485 B2
• Time in Patent Office: Days
• US Class Current: 370/461
• CPC Class Codes: H04W 74/0841 with collision treatment
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A wireless data transmission method includes providing a plurality of radio frequency transmitters. A receiver is provided to receive transmissions from the transmitters. A data format including a plurality of transmission time slots is defined. Each of the transmitters is caused to independently select one of the time slots. The transmitters are used to transmit the transmissions to the receiver in the independently selected time slots.

Claims

1. A wireless data transmission method, comprising:

providing a plurality of radio frequency transmitters;

providing a receiver to receive transmissions from the transmitters;

defining a data format including a plurality of transmission time slots;

causing each of the transmitters to independently select one of the time slots; and

using the transmitters to transmit the transmissions to the receiver in the independently selected time slots.

2. The method of claim 1 wherein the time slots are substantially randomly selected by the transmitters.

3. The method of claim 1 wherein, if at least two of the transmitters conflict by transmitting the transmission in a same one of the independently selected time slots, the method comprises the further step of using the conflicting transmitters to re-transmit the transmissions to the receiver.

4. The method of claim 3 comprising the further step of transmitting acknowledgement codes from the receiver to non-conflicting ones of the transmitters.

5. The method of claim 4 wherein the acknowledgement codes are transmitted to only ones of the non-conflicting transmitters from which the transmissions have been successfully received by the receiver.

6. The method of claim 3 comprising the further step of causing each of the conflicting transmitters to independently re-select one of the time slots, the conflicting transmitters being used to re-transmit the transmissions to the receiver in the independently re-selected time slots.

7. The method of claim 1 wherein the transmissions comprise data packets.

8. A wireless data transmission method, comprising:

providing a plurality of radio frequency transmitters;

providing a plurality of receivers to receive transmissions from the transmitters;

configuring each of the receivers to receive the transmissions on a respective one of a plurality of frequency channels;

defining a data format including a plurality of transmission time slots;

causing each of the transmitters to independently select one of the time slots and one of the frequency channels; and

using the transmitters to transmit the transmissions to the receiver in the independently selected time slots and the independently selected frequency channels.

9. The method of claim 8 wherein the time slots and the frequency channels are substantially randomly selected by the transmitters.

10. The method of claim 8 wherein, if at least two of the transmitters conflict by transmitting the transmission in a same one of the independently selected time slots and in a same one of the independently selected frequency channels, the method comprises the further step of using the conflicting transmitters to re-transmit the transmissions to the receiver.

11. The method of claim 10 comprising the further step of transmitting acknowledgement codes from the receiver to non-conflicting ones of the transmitters.

12. The method of claim 11 wherein the acknowledgement codes are transmitted to only ones of the non-conflicting transmitters from which the transmissions have been successfully received by the receiver.

13. The method of claim 10 comprising the further step of causing each of the conflicting transmitters to at least one of independently re-select one of the time slots and independently re-select one of the frequency channels, the conflicting transmitters being used to re-transmit the transmissions to the receiver in at least one of the independently re-selected time slots and the independently re-selected frequencies.

14. The method of claim 8 wherein the transmissions comprise data packets.

15. A data transmission method, comprising:

wirelessly transmitting data packets from a plurality of sensors to a receiver at substantially random times;

wirelessly transmitting signals to the sensors, the signals being indicative of whether data portions of individual ones of the data packets were received during overlapping time periods; and

repeating the step of wirelessly transmitting data packets at substantially random times for ones of the sensors whose data portions were transmitted during the overlapping time periods.

16. The method of claim 15 wherein the step of wirelessly transmitting signals to the sensors comprises transmitting acknowledgement codes from the receiver to ones of the sensors whose data portions were transmitted during non-overlapping time periods.

17. The method of claim 16 wherein the acknowledgement codes are transmitted to only ones of the sensors from which the data packets have been successfully received by the receiver.

18. The method of claim 15 wherein the step of wirelessly transmitting data packets comprises wirelessly transmitting data packets from a plurality of sensors to a plurality of receivers at substantially random times and in substantially randomly selected frequency channels.

19. The method of claim 18 wherein each of the receivers is configured to receive data packets in respective ones of the frequency channels.

20. The method of claim 18 wherein the signals wirelessly transmitted to the sensors are indicative of whether data portions of individual ones of the data packets were received during overlapping time periods and in same frequency channels, and the step of wirelessly transmitting data packets at substantially random times and in substantially randomly selected frequency channels is repeated for ones of the sensors whose data portions were transmitted during the overlapping time periods and in the same frequency channels.