Wireless communication system with collision avoidance protocol

• US 20060227729A1
• Filed: 04/12/2005
• Published: 10/12/2006
• Est. Priority Date: 04/12/2005
• Status: Abandoned Application

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Budampati, Ramakrishna S., Gonia, Patrick S.
• Application Number:
  US11/103,982
• Publication Number:
  US 20060227729A1
• Time in Patent Office: Days
• US Class Current: 370/278
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• 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 74/0816 with collision avoidance
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A system of wireless infrastructure nodes are communicatively coupled to a number of internally powered leaf nodes. The leaf nodes may have sensors and/or actuators. A wireless leaf node transmits data to an infrastructure node at a time according to a duty cycle. When a collision occurs, the data is retransmitted until an acknowledgement is received from an infrastructure node. A change in a transmission protocol parameter, such as duty cycle/phase of sampling is initiated with such retransmissions. A decision to change the parameter is taken either by the wireless leaf node itself, or by an infrastructure node. Some of the leaf nodes can be transmit-only devices which repeat each data packet a number of times.

Claims

1. A wireless communication system consisting of:

a plurality of transceiver based wireless devices that may have a wireless transceiver for transmitting packets and receiving acknowledgments (ACKs);

a plurality of transmitter based wireless devices that may have a wireless transmitter for transmitting packets;

a plurality of infrastructure wireless devices that may have a wireless transceiver for receiving packets and transmitting ACKs;

wherein

each infrastructure wireless device may be associated to a few transceiver wireless devices and a few transmitter wireless devices;

each associated transceiver wireless device may transmit packets to the infrastructure wireless devices using a transmission protocol parameter;

each associated transmitter wireless device may transmit packets to the infrastructure wireless device using a transmission protocol parameter;

each infrastructure wireless device maintains a list of the transmission protocol parameters for each associated transceiver and transmitter wireless device; and

each infrastructure wireless device may receive the transmitted packets from the associated transceiver and transmitter wireless devices using the list of the transmission protocol parameters.

2. The system of claim 1 wherein:

the transceiver wireless devices have an indication in the transmitted packets to request an ACK from the infrastructure wireless device;

the transmitter wireless devices have an indication in the transmitted packets to not request an ACK from the infrastructure wireless device; and

the infrastructure wireless device has the ability to look at the indication in a received packet and decide to transmit or not transmit an ACK.

3. The system of claim 2 wherein:

the transceiver wireless devices can detect collisions of the current transmitted packet with other wireless devices'"'"' transmitted packets, and shift a transmission protocol parameter for subsequent packets based on the detected collisions;

the transmitter wireless devices transmit the same packet multiple times; and

the infrastructure wireless devices can detect collisions of the current transmitted packet and adjust to the shift in the transmission protocol parameter by the transceiver wireless devices.

4. The system of claim 3 wherein the transmission protocol parameter that is shifted comprises a phase of sampling/duty cycle.

5. The system of claim 3 wherein the transceiver wireless device has a module that retransmits a packet when no ACK is received.

6. The system of claim 5 wherein:

the module includes a request for the shift of the transmission protocol parameter in each retransmission; and

the module shifts the transmission protocol parameter consistent with the request in the retransmission which received an ACK with a response to the request.

7. The system of claim 6 wherein:

the infrastructure wireless device has a response module that sends the ACK with the response to the request for the shift of the transmission protocol parameter; and

the response module shifts the transmission protocol parameter consistent with the request and updates the list of the transmission protocol parameters.

8. The system of claim 5 wherein the module sets a flag indicative of a collision in each retransmission and shifts the transmission protocol parameter consistent with a command received in an ACK to a retransmission.

9. The system of claim 8 wherein:

the infrastructure wireless device has a response module that sends the ACK after receiving a retransmission with a flag indicative of a collision; and

the ACK includes a command to shift the transmission protocol parameter for succeeding packets.

10. The system of claim 9 wherein the infrastructure wireless device shifts the transmission protocol parameter based on the list of the transmission protocol parameters for all the other transmitter and transceiver wireless devices.

11. The system of claim 9 wherein the response module shifts the transmission protocol parameter consistent with the command and updates the list of the transmission protocol parameters.

12. A leaf node in a communication system having leaf nodes and infrastructure nodes, the leaf node comprising:

a wireless transceiver that detects collisions of current packets with other leaf nodes, and shifts a transmission protocol parameter for succeeding packets as a function of the detected collisions.

13. The leaf node of claim 12 wherein the transmission protocol parameter that is shifted comprises a phase of sampling/duty cycle.

14. The leaf node of claim 12 wherein:

the leaf node wireless transceiver receives acknowledgements (ACKs) from the infrastructure nodes in response to a transmission; and

the leaf node wireless transceiver has a module that retransmits a packet when no ACK is received.

15. The leaf node of claim 14 wherein the module includes a request for the shift of the transmission protocol parameter in each retransmission and shifts the transmission protocol parameter consistent with the request in the retransmission which received an ACK.

16. The leaf node of claim 14 wherein the leaf node module sets a flag indicative of a collision in each retransmission and shifts the transmission protocol parameter consistent with a command received in an ACK to a retransmission.

17. A method of transmitting packets implemented in a leaf node in a communication system having leaf nodes and infrastructure nodes, the method comprising:

transmitting a leaf node originated packet;

determining that no acknowledgement of the transmitted packet was received;

re-transmitting the leaf node originated packet with a request to use a new transmission protocol parameter for transmitting future packets;

receiving an acknowledgement; and

transmitting future packets using the new transmission protocol parameter.

18. The leaf node of claim 17 wherein the transmission protocol parameter comprises a phase of sampling/duty cycle.

19. The method of claim 17 wherein the received acknowledgement includes a permission to use the new transmission protocol parameter for transmitting future packets.

20. The method of claim 17 wherein the new transmission protocol parameter is not used unless the received acknowledgement grants permission to use the new phase for transmitting future packets.