Ad-hoc simple configuration

• US 20080037444A1
• Filed: 05/04/2007
• Published: 02/14/2008
• Est. Priority Date: 08/08/2006
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Marvell Semiconductor, Inc. (Marvell Technology Group Limited)
• Inventors: Chhabra, Kapil
• Granted Patent: US 8,619,623 B2
• Time in Patent Office: Days
• US Class Current: 370/254
• CPC Class Codes: H04W 52/0222 in packet switched networks
• CPC Class Codes: H04W 52/0241 where no transmission is received, e.g. out of range of the transmitter
• CPC Class Codes: H04W 52/0254 detecting a user operation or a tactile contact or a motion of the device
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A protocol governing the operation of an ad-hoc WLAN enables each device in the WLAN to be configured as a registrar and/or an enrollee. Accordingly, each device is configurable to support both the registrar as well as enrollee modes of operations. In response to a time-driven user action, the device may be configured to enter into a registrar mode or an enrollee mode. While in the registrar mode, the device enters into an aggressive beaconing phase by setting its beacon contention window to a relatively very small value. The aggressive beaconing increases the probability of the discovery of the registrar by the enrollees. Optionally the device may prompt the user to select between a registrar and an enrollee mode of operation by displaying the option on an LCD panel.

Claims

1. A method of forming an ad-hoc wireless network, the method comprising:

triggering an event in response to a first action taken on a device;

configuring the device as one of an enrollee and a registrar if a second action is taken on the device within a first predefined time of the first action;

configuring the device as the other of the enrollee and the registrar if the second action is not taken on the device within the first predefined time of the first action; and

enabling communications between the device and the second device in an ad-hoc wireless network.

2. The method of claim 1 wherein enabling communication between the device and the second device comprises:

setting a beacon contention window of the device to a value between 0 and 15 time slots if the device is configured as the registrar; and

transmitting beacons in accordance with the set beacon contention window.

3. The method of claim 2 further comprising:

starting a timer;

initiating an attempt to perform a registrar-enrollee handshake if a probe request transmitted by the second device is received by the registrar before the timer'"'"'s elapsed time reaches a second predefined time, where the second device is configured as the enrollee; and

establishing the ad-hoc network between the registrar and the enrollee if the attempt is successful.

4. The method of claim 3 further comprising:

adding N more enrollees to the established ad-hoc network wherein N is a predefined integer greater than 1.

5. The method of claim 3 further comprising:

placing the registrar in an idle mode if the registrar fails to receive an enrollee probe request before the timer'"'"'s elapsed time reaches the second predefined time.

6. The method of claim 5 further comprising:

causing the registrar to exit the idle mode periodically in accordance with a first clock period.

7. The method of claim 6 further comprising:

setting a scanning period of equal to the first clock period.

8. The method of claim 2 further comprising:

reducing the beacon contention window while the registrar receives beacons from other registrars forming an ad-hoc network with the registrar.

9. The method of claim 2 further comprising:

receiving a PIN on the registrar, the PIN being associated with the enrollee seeking to communicate with the registrar.

10. The method of claim 9 wherein the PIN is received via an optical signal.

11. The method of claim 9 wherein the PIN is received via an audio signal.

12. The method of claim 9 wherein the PIN is entered manually by a user.

13. The method of claim 1 further comprising:

starting a timer if the device is configured as the enrollee;

scanning for beacons transmitted by the second device, where the second device is configured as the registrar; and

initiating an extended authentication protocol exchange if the enrollee receives a beacon from the registrar before the timer'"'"'s elapsed time reaches a second predefined time.

14. The method of claim 13 further comprising:

initiating an attempt to perform a registrar-enrollee handshake after the completion of the exchange of the extended authentication protocol; and

establishing the ad-hoc network if the attempt is successful.

15. The method of claim 14 further comprising:

resetting the timer if the attempt is unsuccessful.

16. The method of claim 5 further comprising:

causing the registrar to exit the idle mode in response to a second action.

17. The method of claim 14 further comprising:

starting a registrar application on the enrollee after the ad-hoc network is established.

18. The method of claim 1 further comprising:

setting a beacon contention window of the device to a value between 0 and 10 time slots if the device is configured as the registrar; and

transmitting beacons in accordance with the set beacon contention window.

19. The method of claim 1 further comprising:

setting a beacon contention window of the device to a value between 0 and 5 time slots if the device is configured as the registrar; and

transmitting beacons in accordance with the set beacon contention window.

20. The method of claim 1 wherein the first action corresponds to a pressing of a button.

21. The method of claim 1 wherein the first action corresponds to an issuing of a voice command.

22. A method of selecting a configuration of a device attempting to participate in an ad-hoc network session, the method comprising:

triggering an event in response to a first action;

presenting an option to configure the device as a registrar or an enrollee;

configuring the device as the enrollee if a first option is selected; and

configuring the device as the registrar if a second option is selected.

23. The method of claim 22 wherein the first and second options are displayed on an LCD panel.

24. A device adapted to participate in a wireless ad-hoc network, the device comprising:

a triggering module configured to trigger an event in response to a first action;

a first timer; and

a controller operative to configure the device as one of an enrollee and a registrar if the triggering module detects a second action before the first timer'"'"'s time reaches a known time, the controller further operative to configure the device as the other of the enrollee and the registrar if the triggering module does not detect a second action before the first timer'"'"'s time reaches the known time.

25. The device of claim 24 wherein the controller is further operative to set a beacon contention window of the device to a value between 0 and 15 time slots if the device is configured as the registrar, the device to transmit beacons in accordance with the set beacon contention window.

26. The device of claim 25 further comprising:

a second timer, the controller being further operative to perform a registrar-enrollee handshake if a probe request transmitted by the enrollee is received before the second timer'"'"'s elapsed time reaches a predefined time, the device being operative to establish an ad-hoc network if the handshake is successful.

27. The device of claim 26 wherein the controller is operative to reset the second timer if the handshake is unsuccessful.

28. The device of claim 26 wherein the controller is further operative to add N more enrollees to the established ad-hoc network, wherein N is a predefined integer greater than one.

29. The device of claim 26 wherein the controller is further operative to place the registrar in an idle mode if the registrar fails to receive an enrollee probe request before the second timer'"'"'s time reaches the predefined time.

30. The device of claim 29 wherein the controller is further operative to cause the registrar to exit the idle mode periodically in accordance with a first clock period.

31. The device of claim 25 wherein the controller is further operative to reduce the beacon contention window while the registrar receives beacons from other registrars forming the ad-hoc network with the registrar.

32. The device of claim 25 wherein the registrar is further configured to receive a PIN associated with the enrollee.

33. The device of claim 32 further comprising an optical interface configured to receive the PIN.

34. The device of claim 32 further comprising an audio interface configured to receive the PIN.

35. The device of claim 32 further comprising a user interface configured to receive the PIN via a manual entry by a user.

36. The device of claim 24 wherein the device is configured as the enrollee;

the enrollee further comprising;

a second timer; and

a scanner adapted to scan for beacons transmitted by one or more registrars;

wherein the controller is further operative to initiate an extended authentication protocol exchange if the enrollee receives a beacon from the one or more registrars before the second timer'"'"'s elapsed time reaches a predefined time.

37. The device of claim 36 wherein the controller is further operative to attempt to perform a registrar-enrollee handshake after the completion of the exchange of the extended authentication protocol;

the controller being further operative to establish an ad-hoc network if the attempt is successful.

38. The device of claim 37 wherein the controller is operative to reset the timer if the attempt is unsuccessful.

39. The device of claim 37 wherein the controller is further operative to place the enrollee in an idle mode.

40. The device of claim 37 wherein the controller is further operative to start a registrar application on the enrollee after the ad-hoc network is established.

41. The device of claim 24 wherein the controller is further configured to set a beacon contention window of the device to a value between 0 and 10 time slots if the device is configured as the registrar, the device being configured to transmit beacons in accordance with the set beacon contention window.

42. The device of claim 24 wherein the controller is further configured to set a beacon contention window of the device to a value between 0 and 5 time slots if the device is configured as the registrar, the device to transmit beacons in accordance with the set beacon contention window.

43. The device of claim 24 further comprising a button adapted to receive the first action.

44. The device of claim 24 further comprising an audio interface adapted to receive a voice command representing the first action.

45. The device of claim 29 wherein the controller is further operative to cause the registrar to exit the idle mode in response to a second action.

46. A method of forming a wireless ad-hoc network between a first device and a second device, the method comprising:

turning on the first device;

turning on the second device;

starting a first timer on the first device;

starting a second timer on the second device;

pressing a button on the first device before the first timer'"'"'s elapsed time reaches a predefined time in order to configure the first device as an enrollee;

avoiding a button press on the second device before the second timer'"'"'s elapsed time reaches the predefined time in order to configure the second device as a registrar;

reducing the beacon contention window of the second device;

transmitting beacons from the second device in accordance with the reduced beacon contention window;

intercepting the transmitted beacons via the first device thereby enabling the first device to discover the second device;

performing a handshake operation between the first and second devices; and

forming the ad-hoc network.