WIRELESS TRANSMITTER INITIATED COMMUNICATION SYSTEMS

• US 20070091824A1
• Filed: 10/21/2005
• Published: 04/26/2007
• Est. Priority Date: 10/21/2005
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Gonia, Patrick, Kolavennu, Soumitri, Budampati, Ramakrishna
• Granted Patent: US 8,811,231 B2
• Time in Patent Office: Days
• US Class Current: 370/255
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 1/715 Interference-related aspects
• CPC Class Codes: H04B 2001/7154 with means for preventing interference
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• 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

Wireless communication systems using transmitter initiated communications methods. Several devices in the system listen by following a common frequency hopping sequence. When communication is desired, a transmitting device sends a request to send signal to an addressee; if available, the addressee sends a clear to send signal, and the transmitting device and the addressee then perform communications using a separate frequency hopping sequence. Methods for adding new devices are also included. In an example, a new device uses a discovery frequency hopping sequence to ping a number of frequencies until the common frequency hopping sequence is discovered. In another example, a new device listens on a single frequency forming part of the common frequency hopping sequence until the common frequency hopping sequence overlaps the single frequency.

Claims

1. A wireless communication system comprising a plurality of peer communication devices configured for sending and receiving signals wirelessly wherein:

the peer communication devices follow a first channel succession defining a number of communications channels to which the communication devices are tuned at particular times;

a first peer communication device generates a request to send data to a second peer communication device using a first channel in the channel succession;

the second peer communication device receives the request to send data from the first peer communication device and generates a clear to send data message to the first peer communication device using the first channel;

the first and second peer communication devices follow a second channel succession to perform data transfer between the first peer communication device and the second peer communication device; and

the devices in the system being further configured such that, when a device is added to the system, the new device defaults into a discovery mode wherein the new device learns the system timing and the state of the first channel succession.

2. The system of claim 1 wherein the device that is added to the system observes a selected channel from among the number of communications channels for a period of time predetermined to assure that the peer communication devices will use the observed channel during the period of time.

3. The system of claim 1 wherein the device that is added to the system follows a third channel succession in the discovery mode, the third channel succession changing channels more quickly than the first or second channel successions.

4. The system of claim 1 wherein the device that is added to the system transmits hailing messages on succession of channels until a response is received or a time out is observed.

5. The system of claim 1 wherein the first and second channel successions are pseudo-random frequency hopping spread spectrum successions.

6. The system of claim 1 wherein the first and second channel successions are CDMA successions.

7. The system of claim 1 wherein the second channel succession is defined by the second peer communication device.

8. The system of claim 7 wherein data indicative of the second channel succession is communicated by the second peer communication device to the first peer communication device as part of the clear to send data message.

9. The system of claim 1 further comprising a central time device, wherein the central time device periodically generates a time synchronization signal.

10. The system of claim 9 wherein the first and second peer communication devices are each located a number of hops from the central time device, wherein one of the first or second peer communication device is a closer device with respect to the central time device, wherein, during communication between the first and second peer communication devices, a time synchronization signal is generated by the closer device and communicated to the other device.

11. The system of claim 1 wherein the second channel succession is defined by the first peer communication device.

12. The system of claim 11 wherein data indicative of the second channel succession is communicated by the first peer communication device to the second peer communication device as part of the request to send data message.

13. The system of claim 1 wherein at least one of the plurality of peer communication devices is configured to send a broadcast message to the other peer communication devices using a channel defined in the first channel succession.

14. The system of claim 1 wherein the first peer communication device performs a clear channel assessment on the first channel before sending the request to send message.

15. The system of claim 1 wherein:

a third peer communication device generates a request to send data message to a fourth peer communication device using the first channel after the first and second peer communication devices generate their respective request to send data and clear to send data messages on the first channel;

the fourth peer communication device generates a clear to send data message in response to the request to send data message from the third peer communication device; and

data is transmitted by the third peer communication device to the fourth peer communication device using a channel defined in a third channel succession.

16. The system of claim 15 wherein one of the third or the fourth peer communication device defines the third channel succession.

17. The system of claim 15 wherein the third peer communication device performs a clear channel assessment on the first channel before transmitting the request to send message.

18. A transmitter initiated wireless communication system comprising a number of peer devices configured to generate requests to send data when data is ready to send, the devices in the system configured to follow a first channel succession when not transmitting data, wherein, when a first device is prepared to send data, the device addresses a request to send data to a second device;

the second device sends a clear to send data message to the first device; and

the first and second devices follow a second channel succession when transmitting data, the second channel succession being different from the first channel succession.

19. A wireless communication system comprising a number of peer devices that follow a first channel succession in common for communicating with one another, wherein new devices can be added to the system, wherein, when a new device is added to the system, the new device defaults to a discovery process, the discovery process comprising listening on a single channel chosen from a number of channels included in the first channel succession until either the new device times out, or until a message is generated by one of the existing peer devices in the single channel, wherein, once the message is generated on the single channel, the new device time synchronizes with the other peer devices.

20. A wireless communication system comprising a number of peer devices that follow a first channel succession in common for communicating with one another, wherein new devices can be added to the system, wherein, when a new device is added to the system, the new device defaults to a discovery process, the discovery process comprising following a second channel succession covering channels covered by the first channel succession until either the new device times out, or until a message is generated by one of the existing peer devices and captured by the new device.

21. The system of claim 20 wherein the new device generates a hailing signal at channels determined by the second channel succession.

22. The system of claim 20 wherein the first channel succession is configured to include a repeating frame including a discovery subframe for discovering new devices and an operation subframe for peer devices to communicate with one another.

23. The system of claim 22 wherein the new device generates a hailing signal at channels determined by the second channel succession, the new device operating with a periodicity enabling the new device to hail at least two channels during each discovery subframe.