Method and device for data communication in a network

• US 10,028,306 B2
• Filed: 08/27/2015
• Issued: 07/17/2018
• Est. Priority Date: 08/28/2014
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Baron, Stephane, Guignard, Romain, Viger, Pascal
• Primary Examiner(s): Nowlin, Eric
• Application Number:
  US14/837,126
• Publication Number:
  US 20160066208A1
• Time in Patent Office: 1,055 Days
• CPC Class Codes: H04W 74/085 collision avoidance

Abstract

The invention relates to a communication device and a method of sending data over a communication network. The communication device includes a controller for accessing the network using contention type access mechanism based on computation of back-off values, and includes a plurality of traffic queues for serving data traffic at different priorities. The controller includes a plurality of back-off engines, each associated with one traffic queue and configured to compute a back-off value in accordance with the priority of the associated traffic queue. One or more back-off engine may be adjusted to prevent the back-off value of such back-off engine to reach zero. When an access to the network is obtained for the device. a traffic queue may be selected based on its associated back-off value, and data may be transmitted from the selected traffic queue.

Claims

1. A first communication device for a communication network, comprising:

a plurality of data queues for serving data at different priorities;

a controller for computing back-off values associated with priority, each back-off value corresponding to a respective one of the plurality of data queues, the controller further for accessing the communication network using contention type access mechanism based on the computed back-off values;

a memory; and

at least one processor that is coupled to the memory and that is configured to cause the first communication device

to select a data queue based on a non-zero back-off value corresponding to the data queue, responsive to an obtaining by the first communication device of a transmission opportunity for transmitting data, from among transmission opportunities obtained by another communication device and granted to one or more communication devices belonging to the communication network; and

to transmit data from the selected data queue in the obtained transmission opportunity even though the back-off value corresponding to the selected data queue of the plurality of data queues is not zero.

2. The first communication device according to claim 1, wherein the at least one processor is configured to cause the first communication device to select the data queue having a lowest associated back-off value.

3. The first communication device according to claim 1, wherein the access to the communication network being implemented through an allocated timeslot, and wherein the at least one processor is configured to cause the first communication device to select at least one further data queue according to the duration of the allocated timeslot.

4. The first communication device according to claim 1, wherein the at least one processor is configured to cause the first communication device to apply one or more offset values for adjusting the at least one adjustable back-off engine.

5. The first communication device according to claim 4, wherein the access to the communication network being obtained by the other communication device, and wherein the one or more offset values is/are determined based on a back-off threshold corresponding to the minimum back-off value from data queues of the other communication device.

6. The first communication device according to claim 5, wherein the first communication device comprises means for obtaining said minimum back-off value.

7. The first communication device according to claim 1, wherein the access to the communication network is obtained by the other communication device sharing a timeslot with the first communication device.

8. The first communication device according to claim 7, wherein the at least one processor is configured to cause the first communication device to prevent the back-off value of the at least one back-off engine to reach zero before a back-off value of the other communication device reaches zero.

9. The first communication device of claim 1, wherein the controller comprises a scheduler implementing a time division access mechanism for a group of devices.

10. A method of sending data over a communication network by a first communication device using a plurality of data queues for serving data at different priorities and using a controller for accessing the communication network using contention type access mechanism based on computed back-off values, the method comprising:

computing back-off values associated with priority, each back-off value corresponding to a respective one of the plurality of data queues;

selecting a data queue based on a non-zero back-off value corresponding to the data queue, responsive to an obtaining by the first communication device of a transmission opportunity for transmitting data, from among transmission opportunities obtained by another communication device and granted to one or more communication devices belonging to the communication network; and

transmitting data from the selected data queue in the obtained transmission opportunity even though the back-off value corresponding to the selected data queue of the plurality of data queues is not zero.

11. The method according to claim 10, wherein the selecting step comprises selecting the data queue having a lowest associated back-off value.

12. The method according to claim 10, wherein the access to the communication network is implemented through an allocated timeslot and wherein the selecting step further comprises selecting at least one further data queue according to the duration of the allocated timeslot.

13. The method according to claim 10, further comprising applying one or more offset values for adjusting the back-off values.

14. The method according to claim 13, wherein the access to the communication network is obtained by the other communication device and wherein the one or more offset values is/are determined based on the minimum back-off value from data queues of the other communication device.

15. The method according to claim 14, wherein said minimum back-off value is obtained though an additional timeslot inserted in a timeslot obtained for the transmission or by a distributed mechanism.

16. The method according to claim 10, wherein the access to the communication network is obtained by the other communication device sharing a timeslot with the first communication device.

17. The method according to claim 16 further comprising preventing the back-off value of the at least one traffic queue to reach zero before a back-off value of the other communication device reaches zero.

18. The method according to claim 10, implementing a time division access mechanism for a group of devices for transmitting data onto the communication network.

19. A non-transitory computer-readable medium storing a program which, when executed by a microprocessor or computer system in a first communication device of a communication network, causes the first communication device to perform a method of sending data over the communication network, the method using a plurality of data queues for serving data at different priorities and using a controller for accessing the communication network using contention type access mechanism based on computed back-off values, the method comprising:

computing back-off values associated with priority, each back-off value corresponding to a respective one of the plurality of data queues;

selecting a data queue based on a non-zero back-off value corresponding to the data queue, responsive to an obtaining by the first communication device of a transmission opportunity for transmitting data, from among transmission opportunities obtained by another communication device and granted to one or more communication devices belonging to the communication network; and

transmitting data from the selected data queue in the obtained transmission opportunity even though the back-off value corresponding to the selected data queue of the plurality of data queues is not zero.