System and method employing algorithms and protocols for optimizing carrier sense multiple access (CSMA) protocols in wireless networks

• US 20030058886A1
• Filed: 09/25/2002
• Published: 03/27/2003
• Est. Priority Date: 09/25/2001
• Status: Active Grant

• Current Assignee: ARRIS Enterprises LLC (CommScope Holding Company, Inc.)
• Original Assignee: MeshNetworks, Inc. (Motorola Solutions, Inc.)
• Inventors: Koos, Larry W., Stanforth, Peter J., Whitehill, Eric A.
• Granted Patent: US 7,280,555 B2
• Time in Patent Office: Days
• US Class Current: 370/468
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 28/26 Resource reservation
• 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 and method for achieving enhanced CSMA/CA which improves channel availability and quality of service (QoS) in a wireless communications network, such as an ad-hoc wireless communication network. The system and method are capable of establishing channels to enable communication between nodes in a communication network, such as a wireless ad-hoc communication network, based on the relationship between the average time length of message data packets and the time lengths of the request to send and clear to send messages. The system and method further control a node of the communication network to place a data packet at a location in a queue for retransmission based on a type of information contained in the data packet if the destination node for which the data packet is intended is unable to receive the data packet. The location in the queue is indicative of a duration of time that the node will delay before attempting to resend the data packet to the destination node. The duration of time is shorter when the information includes voice data than when the information includes no voice data. Also, while the data packet is in the queue, the system and method control the node to refrain from sending other data packets to the destination node, while also allowing the node to send another data packet to another destination node.

Claims

1. A method for establishing channels to enable communication between nodes in a communication network, the method comprising:

determining an average time length of message data packets being communicated between said nodes in said communication network;

determining a time length of a request to send message transmitted by a transmitting node to request clearance to send a said message data packet to a destination node, and a time length of a clear to send message transmitted by said destination node to said transmitting node to indicate clearance to send said message data packet; and

establishing a number of data communication channels based on a relationship between said average time length of message data packets and said time lengths of said request to send and clear to send messages on the reservation channel.

2. A method as claimed in claim 1, wherein:

said establishing establishes said number of data communication channels equal to an integer value determined based on a value representing said average time length of message data packets divided by the sum of a value representing said time length of said request to send message and a value representing said time length of said clear to send message.

3. A method as claimed in claim 1, further comprising:

broadcasting data indicating said number of data communication channels to said nodes.

4. A method as claimed in claim 1, wherein:

said network includes a wireless ad-hoc communication network; and

both of said determining steps and said establishing step are performed in relation to said wireless ad-hoc communication network.

5. A system for establishing channels to enable communication between nodes in a communication network, the system comprising:

a component, adapted to determine an average time length of message data packets being communicated between said nodes in said communication network; and

said component being further adapted to determine a time length of a request to send message transmitted by a transmitting node to request clearance to send a said message data packet to a destination node, and a time length of a clear to send message transmitted by said destination node to said transmitting node to indicate clearance to send said message data packet, and to establish a number of data communication channels based on a relationship between said average time length of message data packets and said time lengths of said request to send and clear to send messages on the reservation channel.

6. A system as claimed in claim 5, wherein:

said component is adapted to establish said number of data communication channels equal to an integer value determined based on a value representing said average time length of message data packets divided by the sum of a value representing said time length of said request to send message and a value representing said time length of said clear to send message.

7. A system as claimed in claim 5, wherein:

said component is further adapted to broadcast data indicating said number of data communication channels to said nodes.

8. A system as claimed in claim 5, wherein:

said network includes a wireless ad-hoc communication network; and

said component is in communication with said wireless ad-hoc communication network.

9. A system as claimed in claim 5, wherein:

said component includes an access point of said network, adapted to provide at least some of said nodes with access to other portions of said network or another network.

10. A system as claimed in claim 5, wherein:

said component includes a mobile Internet switching center associated with said network.

11. A computer-readable medium of instructions, adapted to control a component for establishing channels to enable communication between nodes in a communication network, the computer-readable medium of instructions comprising:

a first set of instructions, adapted to control said component to determine an average time length of message data packets being communicated between said nodes in said communication network;

a second set of instructions, adapted to control said component to determine a time length of a request to send message transmitted by a transmitting node to request clearance to send a said message data packet to a destination node, and a time length of a clear to send message transmitted by said destination node to said transmitting node to indicate clearance to send said message data packet; and

a third set of instructions, adapted to control said component to establish a number of data communication channels based on a relationship between said average time length of message data packets and said time lengths of said request to send and clear to send messages on the reservation channel.

12. A computer-readable medium of instructions as claimed in claim 11, wherein:

said third set of instructions is adapted to control said component to establish said number of data communication channels equal to an integer value determined based on a value representing said average time length of message data packets divided by the sum of a value representing said time length of said request to send message and a value representing said time length of said clear to send message.

13. A computer-readable medium of instructions as claimed in claim 11, further comprising:

a fourth set of instructions, adapted to control said component to broadcast data indicating said number of data communication channels to said nodes.

14. A computer-readable medium of instructions as claimed in claim 11, wherein:

said network includes a wireless ad-hoc communication network; and

said first, second and third set of instructions are adapted to control said component which is associated with said wireless ad-hoc communication network.

15. A method for controlling a node of a communication network to send a data packet to a destination node in said communication network, the method comprising:

controlling said node to attempt to send said data packet to said destination node; and

if said node determines that said destination node has not received said data packet, controlling said node to place said data packet at a location in a queue for retransmission based on a type of information contained in said data packet, said location being indicative of a duration of time that said node will delay before attempting to resend said data packet to said destination node.

16. A method as claimed in claim 15, wherein:

said duration of time is shorter when said information includes voice data than when said information includes no voice data.

17. A method as claimed in claim 15, wherein:

while said data packet is in said queue, controlling said node to refrain from sending other data packets to said destination node.

18. A method as claimed in claim 15, wherein:

while said data packet is in said queue, enabling said node to send another data packet to another destination node.

19. A method as claimed in claim 15, wherein:

said network includes a wireless ad-hoc communication network; and

said controlling steps are performed on said node which is adapted to communicate in said wireless ad-hoc communication network.

20. A node, adapted for use in a communication network, the node comprising:

a controller, adapted to control said node to attempt to send said data packet to said destination node; and

said controller being further adapted to determine that said destination node has not received said data packet, and to control said node to place said data packet at a location in a queue for retransmission based on a type of information contained in said data packet, said location being indicative of a duration of time that said node will delay before attempting to resend said data packet to said destination node.

21. A node as claimed in claim 20, wherein:

said duration of time is shorter when said information includes voice data than when said information includes no voice data.

22. A node as claimed in claim 20, wherein:

while said data packet is in said queue, said controller is adapted to control said node to refrain from sending other data packets to said destination node.

23. A node as claimed in claim 20, wherein:

while said data packet is in said queue, said controller is adapted to control said node to send another data packet to another destination node.

24. A node as claimed in claim 20, wherein:

said network includes a wireless ad-hoc communication network; and

said node is adapted to communicate in said wireless ad-hoc communication network.

25. A computer-readable medium of instructions for controlling a node of a communication network to send a data packet to a destination node in said communication network, the computer-readable medium of instructions comprising:

a first set of instructions, adapted to control said node to attempt to send said data packet to said destination node; and

a second set of instructions, adapted to control said node such that if said node determines that said destination node has not received said data packet, said node places said data packet at a location in a queue for retransmission based on a type of information contained in said data packet, said location being indicative of a duration of time that said node will delay before attempting to resend said data packet to said destination node.

26. A computer-readable medium of instructions as claimed in claim 25, wherein:

said duration of time is shorter when said information includes voice data than when said information includes no voice data.

27. A computer-readable medium of instructions as claimed in claim 25, further comprising:

a third set of instructions, adapted to control said node such that while said data packet is in said queue, said node refrains from sending other data packets to said destination node.

28. A computer-readable medium of instructions as claimed in claim 25, further comprising:

a fourth set of instructions, adapted to control said node to send another data packet to another destination node while said data packet is in said queue.

29. A computer-readable medium of instructions as claimed in claim 25, wherein:

said network includes a wireless ad-hoc communication network; and

said first and second set of instructions are adapted to control said node which is adapted to communicate in said wireless ad-hoc communication network.