Systems and methods to detect collisions in channel sense multiple access communications

• US 20060245448A1
• Filed: 03/14/2006
• Published: 11/02/2006
• Est. Priority Date: 03/15/2005
• Status: Active Grant

• Current Assignee: Cornell Research Foundation Incorporated (Cornell University)
• Original Assignee: Cornell Research Foundation Incorporated (Cornell University)
• Inventors: Chan, Douglas S., Berger, Toby
• Granted Patent: US 7,965,733 B2
• Time in Patent Office: Days
• US Class Current: 370/455
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04W 74/0825 with collision detection

Abstract

Methods and systems to perform collision detection (CD) in a communication network.

Claims

1. A method for transmitting information in a network, the method comprising the steps of:

initiating transmission over a communication channel;

monitoring a feedback channel;

modifying transmission parameters for the transmission over the communication channel, if a feedback transmission is detected while monitoring the feedback channel, a duration of the feedback transmission being smaller than duration of the transmission over the communication channel;

determining whether transmission was successful, if transmission continues after modifying transmission parameters.

2. The method of claim 1 wherein the step of modifying transmission parameters comprises a steps of:

determining if transmission should stop; and

rescheduling transmission, it transmission is stopped.

3. The method of claim 1 further comprising the step of:

rescheduling transmission, if transmission was not successful.

11. The method of claim 1 further comprising the step of scheduling transmission.

12. The method of claim 11 wherein the step of scheduling transmission comprises the steps of:

receiving data over the communication channel;

determining communication channel information from the received data;

determining, utilizing the communication channel information, whether to transmit.

13. The method of claim 12 wherein the step of scheduling transmission further comprises the step of:

scheduling, after determining not to transmit, attempted transmission after a predetermined time interval.

14. The method of claim 11 wherein a slotted-Time system is used for transmission;

and wherein the step of scheduling transmission comprises the step of ascertaining a timing of transmission in relation to a timeslot.

15. The method of claim 11 wherein the step of scheduling transmission further comprises the steps of:

receiving feedback channel information;

determining, utilizing the feedback channel information, whether to transmit.

16. The method of claim 15 wherein the step of scheduling transmission further comprises the step of:

scheduling, after determining not to transmit, attempted transmission after a predetermined time interval.

17. The method of claim 15 wherein a slotted-Time system is used for transmission;

and wherein the step of scheduling transmission comprises the step of ascertaining a timing of transmission in relation to a timeslot.

18. The method of claim 15 wherein the step of scheduling transmission further comprises the step of:

determining transmission parameters, after determining to transmit.

19. The method of claim 15 wherein the step of receiving feedback channel information comprises the step of obtaining a number of transmissions present in the communications channel;

and wherein the step of determining whether to transmit comprises the step of determining whether the number of transmissions is at most equal to a predetermined number of transmissions.

20. The method of claim 11 wherein the step of scheduling transmission comprises the steps of:

receiving data over the communication channel;

determining, from the received data, whether the communication channel is in use;

scheduling transmission, after determining the communication channel not to be in use.

21. The method of claim 20 wherein the step of scheduling transmission further comprises the step of:

scheduling, after determining the communication channel to be in use, attempted transmission after a predetermined time interval.

22. The method of claim 20 wherein a slotted-Time system is used for transmission;

and wherein the step of scheduling transmission comprises the step of ascertaining a timing of transmission in relation to a timeslot.

4. A method for receiving information over a communication channel, the method comprising the steps of:

monitoring the communication channel for transmission;

determining whether at least one transmission is present in the communication channel;

initiating receipt of the at least one transmission, if at least one transmission is present in the communication channel;

determining whether the at least one transmission should be stopped;

determining whether, if the at least one transmission is not stopped, whether transmission has been completed;

notifying at least one transmitting node of outcome of determination, a duration of a notifying transmission being smaller than duration of transmission over the communication channel.

5. The method of claim 4 further comprising the step of:

transmitting, if at least one transmission is present, a feedback signal over a feedback channel, a duration of the feedback signal being smaller than duration of said at least one transmission over the communication channel.

6. The method of claim 5 wherein at least one transmitting node ceases transmission based on said feedback signal.

7. The method of claim 4 where in the step of notifying transmitting nodes of outcome determinations comprises the step of:

notifying, if it is determined that at least one transmission has been completed, a node transmitting the at least one transmission of completion.

8. The method of claim 4 wherein the step of notifying transmitting nodes of outcome determinations comprises the step of:

notifying, if it is determined that the at least one transmission should be stopped, a node transmitting the at least one transmission to stop transmitting.

9. The method of claim 4 further comprising the step of:

if all transmissions have not been stopped, providing communication channel conditions to transmitting nodes.

10. The method of claim 4 further comprising the step of:

if it is determined that all transmissions should be stopped, notifying all transmitting nodes to stop transmission.

23. A transmitter system comprising:

a transmitter/receiver subsystem comprising;

a transmitter/receiver portion capable of transmitting information over a communication channel and of receiving information transmitted over a feedback channel;

said transmitter/receiver subsystem be capable of accessing the communication channel and the feedback channel through a physical layer; and

a scheduling component capable of scheduling transmission of information over the communication channel,

and

a transmitter/receiver control subsystem capable of modifying transmission parameters for the transmission over the communication channel and of determining whether information was successfully transmitted;

a duration of feedback transmission over the feedback channel being smaller than duration of transmission over the communication channel.

24. The transmitter system of claim 23 wherein said transmitter/receiver control subsystem is also capable of determining if transmission should stop and of rescheduling transmission, it transmission is stopped.

25. The transmitter system of claim 23 wherein said transmitter/receiver control subsystem is also capable of rescheduling transmission, if transmission was not successful.

26. The transmitter system of claim 23 wherein a slotted-Time system is used for transmission;

and wherein said scheduling component is also capable of ascertaining a timing of transmission in relation to a timeslot;

a duration of feedback transmission over the feedback channel being at least one time slot.

27. The transmitter system of claim 23 wherein said transmitter/receiver control subsystem comprises:

at least one processor; and

at least one computer usable medium having computer readable code embodied there in,

said computer readable code being capable of causing said at least one processor to;

modify transmission parameters for the transmission over the communication channel, if a feedback transmission is detected while monitoring the feedback channel;

determine whether transmission was successful, if transmission continues after modifying transmission parameters

28. The transmitter system of claim 27 wherein said computer readable code, in causing said at least one processor to modify transmission parameters, is capable of causing said at least one processor to:

determine if transmission should stop; and

reschedule transmission, it transmission is stopped.

29. The transmitter system of claim 27 wherein said computer readable code is also capable of causing said at least one processor to:

reschedule transmission, if transmission was not successful.

30. The transmitter system of claim 23 wherein said scheduling component comprises:

at least one processor; and

at least one computer usable medium having computer readable code embodied there in,

said computer readable code being capable of causing said at least one processor to;

receive data over the communication channel;

determine communication channel information from the received data;

determining, utilizing the communication channel information, whether to transmit.

31. The transmitter system of claim 30 wherein said computer readable code is also capable of causing said at least one processor to:

schedule, after determining not to transmit, attempted transmission after a predetermined time interval.

32. The transmitter system of claim 30 wherein said computer readable code is also capable of causing said at least one processor to:

determine transmission parameters, after determining to transmit.

33. The transmitter system of claim 23 wherein said scheduling component comprises:

at least one processor; and

at least one computer usable medium having computer readable code embodied there in,

said computer readable code being capable of causing said at least one processor to;

receive feedback channel information;

determine, utilizing the feedback channel information, whether to transmit.

34. The transmitter system of claim 33 wherein said computer readable code is also capable of causing said at least one processor to:

schedule, after determining not to transmit, attempted transmission after a predetermined time interval.

35. The transmitter system of claim 33 wherein, in receiving feedback channel information, said computer readable code is capable of causing said at least one processor to obtain a number of transmissions present in the communications channel;

and wherein, in determining whether to transmit, said computer readable code is capable of causing said at least one processor to determine whether the number of transmissions is at most equal to a predetermined number of transmissions.

36. The transmitter system of claim 23 wherein said scheduling component comprises:

at least one processor; and

at least one computer usable medium having computer readable code embodied there in,

said computer readable code being capable of causing said at least one processor to;

receive data over the communication channel;

determine, from the received data, whether the communication channel is in use;

schedule transmission, after determining the communication channel not to be in use.

37. A receiver system comprising:

a reception/transmission control subsystem capable of determining whether transmissions over a communication channel are present, of initiating receipt of transmissions, of determining whether to stop any transmission, and of determining whether any transmissions has been completed; and

a receiving/transmitting subsystem capable of receiving transmissions and of notifying, over a feedback channel, transmitting nodes of outcome determinations;

said receiving/transmitting subsystem being capable of receiving control information from said reception/transmission control subsystem and of receiving determinations of transmissions completion and of transmission stoppage from said reception/transmission control subsystem;

said receiving/transmitting subsystem being capable of receiving transmissions from a communication channel;

a duration of notifying transmission over the feedback channel being smaller than duration of transmission over the communication channel.

38. The transmitter system of claim 37 wherein said receiving/transmitting subsystem is also capable of transmitting, if at least one transmission is present, a feedback signal over the feedback channel, a duration of the feedback signal being smaller than duration of said at least one transmission over the communication channel.

39. The transmitter system of claim 37 wherein said reception/transmission control subsystem comprises:

at least one processor; and

at least one computer usable medium having computer readable code embodied there in,

said computer readable code being capable of causing said at least one processor to;

determine whether at least one transmission is present in the communication channel;

initiate receipt of the at least one transmission, if at least one transmission is present in the communication channel;

determine whether the at least one transmission should be stopped;

determine whether, if the at least one transmission is not stopped, whether transmission has been completed;

notify at least one transmitting node of outcome of determination, a duration of a notifying transmission being smaller than duration of transmission over the communication channel.