Channel scanning

• US 7,809,013 B2
• Filed: 03/24/2005
• Issued: 10/05/2010
• Est. Priority Date: 03/24/2005
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Intel Corporation
• Inventors: Waxman, Shay
• Primary Examiner(s): Ngo; Ricky
• Assistant Examiner(s): Phung; Luat
• Application Number:
  US11/090,747
• Publication Number:
  US 20060215627A1
• Time in Patent Office: 2,021 Days
• Field of Search: 370/464, 370/445, 370/338, 370/238, 370/311, 455/161.1, 455/434
• US Class Current: 370/464
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information

Abstract

A method of operation in a communications node is disclosed. The method of operation includes the communications node scanning a plurality of channels simultaneously during a period of time, with the communications node selecting for signal processing a first signal, in a first channel in the plurality of channels, in a first sub-period of time in the period of time. The method of operation includes the communications node selecting for signal processing a second signal, in a second channel in the plurality of channels, in a second sub-period of time in the period of time. Embodiments of the present invention include but are not limited to communications nodes and devices, subsystems, and systems equipped to operate in the above described manner.

Claims

1. A method of operation in a communications node comprising:

scanning, by the communications node, a first plurality of channels simultaneously to detect one or more beacon transmissions during a first period of time;

selecting, by the communications node, a signal in a first channel of the first plurality of channels for signal processing;

determining, by the communications node, that the signal in the first channel of the first plurality of channels persists beyond a duration of a beacon signal based at least in part on the signal processing;

deselecting, by the communication node, the first channel of the first plurality of channels from simultaneous scanning for a remainder of the first period of time to prevent receipt of overlapping signals on the first plurality of channels;

scanning, by the communication node, a second plurality of channels simultaneously to detect one or more beacon transmissions during a second period of time, wherein the first period of time is different than the second period of time; and

detecting, by the communications node, a first beacon signal in a first channel of the second plurality of channels and a second beacon signal in a second channel of the second plurality of channels during the second period of time.

2. The method of claim 1, wherein said simultaneous scanning of the first plurality of channels and the second plurality of channels is performed by one receiver.

3. The method of claim 1, wherein the detecting of the first beacon signal and the second beacon signal comprises detecting a first beacon signal that does not temporally overlap in time with a second beacon signal.

4. The method of claim 1, further comprising scanning of the first channel of the first plurality of channels by itself.

5. The method of claim 4, wherein said scanning of the first channel of the first plurality of channels by itself occurs in a future scanning cycle.

6. The method of claim 4, wherein said scanning of the first channel of the first plurality of channels by itself occurs immediately upon the signal in the first channel of the first plurality of channels persisting beyond the calculated or pre-determined period of time.

7. The method of claim 1, further comprising scanning, by the communications node, a second channel of the first plurality of channels by itself in response to the deselecting.

8. The method of claim 1, further comprising excluding by the communications node, the first channel of the first plurality of channels from future simultaneous scans of the first plurality of channels based at least in part on the determining.

9. The method of claim 1, further comprising selecting by the communications node, one of the first plurality of channels or the second plurality of channels as an operational channel.

10. The method of claim 1, wherein the communications node comprises a client operating on a wireless network.

11. The method of claim 1, wherein the first beacon signal is transmitted by a second communications node, the second beacon signal is transmitted by a third communications node, and the second and the third communications nodes are synchronized to a common clock.

12. A communications apparatus comprising:

a plurality of filter blocks, wherein the plurality of filter blocks are configured to filter a plurality of carrier signals received over a plurality of independent channels, wherein the plurality of independent channels are scanned simultaneously;

a plurality of carrier sensors correspondingly coupled to the plurality of filter blocks, each of the plurality of carrier sensors to detect a corresponding carrier signal in the plurality of carrier signals;

a multiplexer coupled to the plurality of filter blocks and the plurality of carrier sensors, the multiplexer to select an output of one of the plurality of filter blocks based at least in part upon an output of one of the plurality of carrier sensors; and

a controller coupled to the plurality of carrier sensors to at least partially control their operation, wherein the controller is configured to determine if a carrier signal persists beyond a duration of a beacon signal, and in response to the determination, deselect the carrier signal from a simultaneous scan for a remainder of the simultaneous scan to prevent receipt of overlapping carrier signals.

13. The communications apparatus of claim 12, wherein a filter block in the plurality of filter blocks comprises a filter and a digital down-converter.

14. The communications apparatus of claim 12, further comprising an analog-to-digital converter coupled to the plurality of filters, the analog-to-digital converter to receive a plurality of analog signals.

15. The communications apparatus of claim 12, further comprising a decoder coupled to the multiplexer, the decoder to decode a signal relayed by the multiplexer.

16. The communications apparatus of claim 12, wherein the communications apparatus comprises a client operating on a wireless network.

17. The communications apparatus of claim 12, wherein the communications apparatus comprises an 802.11 compliant or compatible station.

18. A communications system comprising:

one or more antenna(e), designed to at least facilitate reception of a plurality communication signals, wherein the plurality of communication signals are received from a plurality of communication channels that are scanned simultaneously; and

a communications apparatus, the communications apparatus coupled to at least one of the one or more antenna(e), and including

a plurality of filter blocks, wherein the plurality of filter blocks are configured to filter the plurality of communication signals received over the plurality of communication channels,

a plurality of carrier sensors correspondingly coupled to the plurality of filter blocks, each of the plurality of carrier sensors to detect a corresponding communication signal in a plurality of communication signals,

a multiplexer coupled to the plurality of filter blocks and the plurality of carrier sensors, the multiplexer to select an output of one of the plurality of filter blocks based at least in part upon an output of one of the plurality of carrier sensors, and

a controller coupled to the plurality of carrier sensors to at least partially control their operation, wherein the controller is configured to determine if a communication signal persists beyond a duration of a beacon signal, and in response to the determination, deselect the carrier signal from a simultaneous scan for a remainder of the simultaneous scan to prevent receipt of overlapping carrier signals.

19. The communications system of claim 18, wherein the communications apparatus comprises an 802.11 compliant or compatible station.

20. The communications system of claim 18, wherein the communications apparatus comprises a selected one from the group consisting of a cellular phone, a video camera, a personal digital assistant, and a handheld gaming device.

21. A non-transitory computer readable medium comprising:

a storage medium; and

a plurality of instructions stored in the storage medium, the instructions designed to enable an apparatus to;

scan a plurality of channels simultaneously during a period of time to detect one or more beacon transmissions;

select a signal in a first channel of the plurality of channels for signal processing;

determine that the first signal in the first channel of the plurality of channels persists beyond a duration of a beacon signal based at least in part on the signal processing; and

deselecting the first channel of the plurality of channels from simultaneous scanning for a remainder of the period of time based at least in part on the determination to prevent receipt of overlapping signals on the plurality of channels.

22. The computer readable medium of claim 21, wherein the instructions are further designed to scan the channel of the plurality of channels independent of the plurality of channels based at least in part on the determination.

23. The computer readable medium of claim 21, wherein the instructions are further designed to select one of the plurality of channels as an operational channel.