Coexistence mechanism for multiple channels

• US 8,797,881 B2
• Filed: 06/13/2011
• Issued: 08/05/2014
• Est. Priority Date: 06/13/2011
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Hart, Brian Donald, Rangarajan, Raghuram, Hedayat, Ahmadreza
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): HALIYUR, VENKATESH N
• Application Number:
  US13/158,945
• Publication Number:
  US 20120314583A1
• Time in Patent Office: 1,149 Days
• Field of Search: 370203-464, 375224-260
• US Class Current: 370/241
• CPC Class Codes: H04L 1/00 Arrangements for detecting or preventing errors in the information received correcting synchronisation H04L7/00
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 74/0816 with collision avoidance

Abstract

In accordance with an example embodiment, there is disclosed herein a coexistence mechanism for multiple channels. A plurality of channels are monitored to determine which channels are available for communications. Upon receiving a request to establish communications on a channel set within the plurality of channels, a response is sent to the request on at least one in the channel set. The response comprises data representative of which channels from the channel set are available for communications. Optionally, the response may include data indicating how long the unavailable channels will be occupied.

Claims

1. An apparatus, comprising:

a plurality of transceivers for sending and receiving data on a plurality of channels;

a plurality of detectors coupled with the plurality of transceivers and having detector outputs; and

a controller coupled with the plurality of detectors, the controller comprising a mid-packet clear channel assessment circuit configured to determine a subset of the plurality of channels that are available for communication;

wherein the plurality of detectors monitor the plurality of channels;

wherein the controller is operable to receive a signal on at least one of the plurality of channels, the signal comprising data representative of a request to establish communications on a set of channels selected from the plurality of channels;

wherein the controller determines from monitoring the plurality of detector outputs which channels from the set of channels are available for establishing communications;

wherein the controller sends a response to the request to establish communications on at least one of the channels available for establishing communications;

wherein the response comprises data representative of which channels from the set of channels and from the subset of channels are available channels for establishing communications;

wherein the response comprises data representative of which channels from the set of channels are unavailable channels for establishing communications; and

wherein the response comprises data representative of a time period when the unavailable channels are expected to be available.

2. The apparatus of claim 1, wherein the controller determines which channels from the set of channels are available for establishing communications from a clear channel assessment of the set of channels.

3. The apparatus of claim 1, the plurality of wireless transceivers further comprise a decoder for decoding a physical layer header;

and

wherein the controller determines a time period that an unavailable channel selected from the set of channels is unavailable based on a duration field decoded in the physical layer header.

4. The apparatus of claim 3, wherein the duration field comprises data representative of a data rate and number of octets;

and

wherein the controller determines the time period that an unavailable channel is unavailable from the data representative of the data rate and number of octets.

5. The apparatus of claim 3, wherein the duration field comprises a data representative of a modulation and coding scheme and number of octets;

and

wherein the controller determines the time period that an unavailable channel is unavailable from the data representative of the modulation and coding scheme, and number of octets.

6. The apparatus of claim 3, wherein the response further comprises data representative of an amount of time that the channel will be busy;

and

wherein the controller determines the time period that an unavailable channel is unavailable from data representative of an amount of time that the channel will be busy.

7. The apparatus of claim 1, further comprising a decoder coupled with the detectors for decoding a media access control layer header;

wherein the controller determines a time period that an unavailable channel selected from the set of channels is unavailable based on a duration field decoded in the media access control layer header.

8. The apparatus of claim 7, wherein the response further comprises data representative of the time period that the unavailable channel is unavailable.

9. The apparatus of claim 1, wherein the controller sends the response to the request to establish communications on a plurality of the channels available for establishing communications.

10. A method, comprising:

monitoring a plurality of channels to determine which channels are unavailable for establishing communications;

monitoring for a mid-packet clear channel assessment to determine a subset of channels available for establishing the communication;

receiving a signal comprising data representative of a request to establish communications on a set of the plurality of channels;

determining, by a processor, at least one unavailable channel from the set of channels from monitoring the plurality of channels and from the subset of channels from the mid-packet assessment;

responding to the request to establish communications on the set of the plurality of channels with data representative of the at least one unavailable channel from the set of channels; and

responding to the request to establish communications on the set of the plurality of channels with data representative of a time period when the at least one unavailable channel is expected to be available.

11. The method of claim 10, wherein the response is sent on a plurality of available channels.

12. The method of claim 10, further comprising determining for the at least one unavailable channel a time period that the unavailable channel will be unavailable;

and

wherein responding to the request to establish communications further comprises the time period that the at least one unavailable channel will be unavailable.

13. The method of claim 12, wherein determining for the at least one unavailable channel a time period that the unavailable channel will be unavailable comprises decoding a signal received on the unavailable channel;

and

determining the time period from data in the decoded signal.

14. Logic encoded in at least one non-transitory computer readable storage medium for execution by a processor, and when executed by a processor operable to:

receive data indicating which channels selected from a plurality of channels are available for establishing communications;

monitor for a mid-packet clear channel assessment to determine a subset of channels available for establishing the communication

receive a request to establish communications on a set of channels of the plurality of channels;

determine, which channels of the set of channels and of the subset of channels are available channels for communications; and

send a response to the request to establish communications on at least one of the available channels, the response comprising data representative of at least one available channel of the available channels for communication and data representative of at least one unavailable channel, wherein the response comprises data representative of a time period when the at least one unavailable channel is expected to be available.

15. The logic set forth in claim 14, wherein the response is sent on a plurality of available channels.

16. The logic set forth in claim 14, further operable to determine a time period that an unavailable channel of the set of channels will be unavailable.

17. The logic set forth in claim 16, further operable to decode a signal in a received header to determine the time period that the unavailable channel will be unavailable.

18. The logic set forth in claim 16, wherein the response further comprises the time period that the unavailable channel will be unavailable.