NETWORK ENTRY AND DEVICE DISCOVERY FOR COGNITIVE RADIO NETWORKS

• US 20100246434A1
• Filed: 11/24/2008
• Published: 09/30/2010
• Est. Priority Date: 11/27/2007
• Status: Active Grant

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: CHALLAPALI, KIRAN, WANG, JIANFENG
• Granted Patent: US 8,817,710 B2
• Time in Patent Office: Days
• US Class Current: 370/253
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource

Abstract

A device (400) scans and classifies each channel within a spectrum of channels (215-270) as being occupied or unoccupied (255), and, if occupied, whether it is occupied by a primary user (240), a secondary user (230), or an unknown user (260). As a secondary device (400), transmissions are avoided on channels occupied by primary users (490). The device selectively joins an existing network of secondary devices, or establishes a new network on an unoccupied channel (125), based on the quality of service (QoS) that the channel can provide and/or other factors. If the device is paired with a target device (115), the paired device advertises itself on a selected channel (345-360) for a period that is at least as long as the time required to scan all channels, to facilitate discovery in the event that the target device is also in a search mode. The advertising duration randomly alternates (345) among integer multiples of the scan duration.

Claims

1. A method comprising:

selecting (215) a channel of a plurality of available channels;

monitoring (220) the channel to determine a classification of the channel as being one of;

used by a primary user (240),

used by one or more secondary users (230),

used by an unknown class of user (260), and

unused (255);

storing (440) the classification of the channel, and

repeating (270) the selecting and monitoring until each of the plurality of available channels has been classified.

2. The method of claim 1, wherein determining (230) the channel as being used by one or more secondary users includes detecting one or more beacon signals.

3. The method of claim 2, wherein determining (240) the channel as being used by a primary user (490) includes detecting features that are characteristic of the primary user.

4. The method of claim 3, wherein determining (260) the channel as being used by an unknown class of user includes detecting energy above a threshold that does not correspond to one or more beacons and does not correspond to the features that are characteristic of the primary user (490).

5. The method of claim 1, including informing a user of the classifications of one or more of the plurality of available channels.

6. The method of claim 1, including (125) if at least one channel is being used by one or more secondary users, joining a network on the at least one channel.

7. The method of claim 6, wherein joining the network is based on one of a user directive, association with at least one of the one or more secondary users, association with the network, a QoS characteristic of the network, and an amount of traffic on the network.

8. The method of claim 1, including if at least one channel is unused, transmitting an advertising beacon on the at least one channel (125).

9. The method of claim 1, including if the channel is being used by one or more secondary users, storing (440) an identification of each of the one or more secondary users (235) on the channel.

10. The method of claim 9, including accessing the stored identification of each secondary user to locate a target user (335), and joining a network on the channel associated with the identification of the target user (375).

11. The method of claim 1, including receiving an other classification of a channel of the plurality of channels from one of the secondary users, and modifying the classification of the channel based on the other classification.

12. The method of claim 1, including transmitting the classification of one or more of the plurality of channels to one or more of the secondary users.

13. A method comprising:

scanning (330) a plurality of channels for a beacon of a target device for a scan duration, and

if (335) the beacon of the target device is not detected;

randomly selecting (345) an advertise duration from among a set of predefined durations,

transmitting (350) an advertising beacon on a select channel (340) during the advertise duration, and

if (355) a response to the advertising beacon is not received from the target device;

repeating (365) the scanning (330) of one or more of the plurality of channels and transmitting (350) of the advertising beacon at another select channel;

otherwise;

establishing communication (375) with the target device.

14. The method of claim 13, including terminating (365) the repeating, and transmitting the advertising beacon on one of the plurality of available channels (370).

15. The method of claim 14, wherein terminating (365) the repeating is based on at least one of a predefined time limit, a predefined number of repetitions, a role of the target device, and a user input.

16. The method of claim 13, wherein selecting (340) the select channel includes selecting the select channel from among channels of the plurality of channels that do not exhibit use by a primary user.

17. The method of claim 13, wherein the repeating (365) includes storing (440) a record of each scanned channel being one of used by a primary user (240), used by one or more secondary users (230), used by an unknown class of user (260), and unused (255).

18. The method of claim 13, wherein values of the set of predefined durations are dependent upon the scan duration (345).

19. The method of claim 18, wherein values of the set of predefined durations include the scan duration and twice the scan duration (345).

20. The method of claim 13, wherein the one or more of the plurality of channels are selected (340) from among channels at which a primary user was not detected during the scanning.

21. A method of network discovery by a device (400) among a plurality of channels having primary (490) and secondary (400) users, comprising:

if (115) the device is paired with a target device;

if (315) the device is not a master of a master-slave pair;

scanning (330) a plurality of channels for a beacon of the target device for a scan duration, and

if (335) the beacon of the target device is not detected;

transmitting (350) an advertising beacon on a select channel (340) during an advertise duration (345-360), and

if (355) a response to the advertising beacon is not received from the target device, repeating (365) the scanning (330) of one or more of the plurality of channels and transmitting (350) of the advertising beacon at another select channel (340);

otherwise, if (315) the device is the master of the master-slave pair, transmitting (390) an advertising beacon on a select channel (385); and

establishing (145) communication with the target device;

otherwise, if (115) the device is not paired with the target device;

selecting (215) a channel of the plurality of available channels;

monitoring (220) the channel to determine a classification of the channel based at least upon whether a primary or secondary user is detected (230, 240),

storing (440) the classification of the channel, and

repeating (270) the selecting (215) and monitoring (220) until each of the plurality of available channels has been classified; and

selecting (125) a select channel from among one or more of the plurality of channels at which at least one secondary user is detected, and

establishing communication (125) with the at least one secondary user on the select channel.

22. An apparatus (400) comprising:

a receiver (410);

a transmitter (430);

a controller (450) that is configured to control the receiver to tune to each channel of a plurality of channels;

a channel classifier (420) that is configured to determine a classification of each channel as being one of;

used by a primary user (240),

used by one or more secondary users (230),

used by an unknown class of user (260), and

unused (255); and

a memory (440) that is configured to store the classification of each channel,

wherein the controller (450) is configured to control the transmitter (430) to selectively effect each of (125);

joining a network on a select channel that is classified as being used by one or more secondary users, and

establishing a network on a select channel that is classified as being unused.

23. The apparatus (400) of claim 22, wherein the controller (450) is configured to selectively join (125) the network based on one of a user directive, association with at least one of the one or more secondary users, association with the network, a QoS characteristic of the network, and an amount of traffic on the network.

24. An apparatus (400) comprising:

a receiver (410),

a transmitter (430), and

a controller (450) that is configured to;

control the receiver (410) to scan (330) each of a plurality of channels for a beacon of a target device for a scan duration, and

if (335) the beacon of the target device is not detected;

randomly select (345) an advertise duration from among a set of predefined durations, and

control the transmitter (430) to transmit (350) an advertising beacon on a select channel (340) during the advertise duration (345-360), and

if (355) a response to the advertising beacon is not received from the target device, repeating (365) the control of the receiver (410) to scan (330) one or more of the plurality of channels and the control of the transmitter (430) to transmit (350) the advertising beacon at another select channel (340);

otherwise, if (335, 355) the target device is detected, control the transmitter (430) and receiver (410) to establish communication (375) with the target device.

25. The apparatus of claim 24, wherein the controller (350) is configured to terminate (365) the repeating of the scan (330) of the one or more of the plurality of channels based on at least one of a predefined time limit, a predefined number of repetitions, a role of the target device, and a user input;

and transmitting (125) the advertising beacon on one of the plurality of available channels.