Wireless device authentication at mutual reduced transmit power

• US 6,928,295 B2
• Filed: 01/30/2002
• Issued: 08/09/2005
• Est. Priority Date: 01/30/2001
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Olson, Erlend, Murphy, K.C.
• Primary Examiner(s): Beamer, Temica M.
• Application Number:
  US10/060,975
• Publication Number:
  US 20020115426A1
• Time in Patent Office: 1,287 Days
• Field of Search: 455/410, 455/411, 455/435.1, 455/41.2, 455/41.3
• US Class Current: 455/522
• CPC Class Codes: H04L 63/0492 by using a location-limited connection, e.g. near-field communication or limited proximity of entities
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/104 Grouping of entities
• CPC Class Codes: H04L 63/1475 Passive attacks, e.g. eavesdropping or listening without modification of the traffic monitored
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 12/12 Detection or prevention of fraud
• CPC Class Codes: H04W 52/283 Power depending on the position of the mobile
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A system and method for facilitating the authentication of wireless devices in an environment with multiple wireless networks. A user wishing to join an operating wireless network can bring his wireless device within close physical proximity, for example, less than one meter, of a device in the network that he wishes to join. The user then presses an authenticate button, which causes both devices to enter a low transmission power mode. In such case, the devices are only capable of operation within the close proximity. Being in low power mode will diminish the possibility of eavesdropping on the authentication process. Power down mode also reduces the amount of message traffic in the area and saves scarce power and processing resources at the nodes, which are now out of range. Authentication then takes place in low power mode and once completed, both devices resume normal power levels and continue communicating normally.

Claims

1. In the operation of a point-to-point wireless network managed by a master device, a method for adding a new device to the point-to-point wireless network, the method comprising:

establishing a second point-to-point wireless network that includes the master device and at least one other wireless device;

placing the new device a proximate distance from the master device of the point-to-point wireless network, wherein the proximate distance between the master device and the new device is substantially less than the maximum operating range of the devices;

sending a message from the new device to the master device, the message conveying a request from the new device to join the point-to-point wireless network;

the master device and the new device communicating packet data with one another at reduced transmit power levels that are sufficient to maintain radio communications between the devices at the proximate distance to authenticate the new device and to admit the new device into the point-to-point wireless network;

communicating, by the new device and the master device at normal transmit power levels after the new device has been added to the point-to-point wireless network; and

during a period of time when the master device and the new device are communicating packet data with one another at the reduced transmit power levels, the master device communicating packet data with the at least one other wireless device of the additional point-to-point wireless network on an interspersed basis at normal transmit power levels.

2. The method of claim 1, wherein:

a plurality of other point-to-point wireless networks provide overlapping coverage with the point-to-point wireless network; and

reducing the radio frequency power outputs of the new device and the master device to a transmit power level sufficient to maintain radio communications between the devices at the reduced distance prevents the request from being received by masters of the other point-to-point wireless networks.

3. The method of claim 1, wherein reducing the transmit power levels of the new device and the master device to a power level sufficient to maintain radio communications between the devices at the reduced distance prevents the request from being intercepted by eavesdropping point-to-point wireless networks.

4. The method of claim 1, wherein the point-to-point wireless network operates according to the Bluetooth Specification.

5. The method of claim 4, wherein:

the point-to-point wireless network is a first piconet serviced by the master device;

the second point-to-point wireless network is a second piconet serviced by the master device; and

the first piconet and the second piconet together form a scatternet.

6. The method of claim 1, wherein the reduced transmit power level of the new device differs slightly from the reduced transmit power level of the master device.

7. The method of claim 1, wherein the master device communicating packet data with the at least one other wireless device of the additional point-to-point wireless network on an interspersed basis at normal transmit power levels comprises:

the master device setting its transmit power to a reduced transmit power level;

the master device transmitting at least one data packet to the new device at the reduced power level;

the master device setting its transmit power to a normal transmit power level;

the master device transmitting at least one data packet to a device of the additional point-to-point wireless network;

the master device setting its transmit vower to a reduced transmit power level; and

the master device transmitting at least one data packet to the new device at the reduced power level.

8. The method of claim 1, wherein:

the new device has limited user interface capabilities; and

the new device indicates to its user that it has joined the point-to-point wireless network.

9. A method for operating a first point-to-point wireless network and an overlapping second point-to-point wireless network, the method comprising:

communicating packet data between a master device and at least one other wireless device of the first point-to-point wireless network at normal transmit power levels;

communicating packet data between the master device and at least one other wireless device of the second point-to-point wireless network at normal transmit power levels;

admitting a new device to the first point-to-point wireless network by;

placing the new device a proximate distance from the master device of the first point-to-point wireless network, wherein the proximate distance between the master device of the first point-to-point wireless network and the new device is substantially less than the maximum operating range of the devices;

sending a request from the new device to the master device to join the point-to-point wireless network;

the master device and the new device communicating packet data with one another at reduced transmit power levels that are sufficient to maintain radio communications between the devices at the proximate distance in order to authenticate the new device and to add the new device to the first point-to-point wireless network;

communicating, by the new device and the master device of the first point-to-point wireless network at normal transmit power levels after the new device has been added to the first point-to-point wireless network; and

during a period of time when the master device and the new device are communicating packet data with one another at the reduced transmit power levels, the master device communicating packet data with the at least one other wireless device of the second point-to-point wireless network on an interspersed basis at normal transmit power levels.

10. The method of claim 9, further comprising:

during a period of time when the master device and the new device are communicating packet data with one another at the reduced transmit power levels, the master device communicating packet data with the at least one other wireless device of the first point-to-point wireless network on an interspersed basis at normal transmit power levels.

11. The method of claim 9, wherein sending the request from the new device to the master device to join the point-to-point wireless network is communicated at a reduced transmit power level.

12. The method of claim 9, wherein sending the request from the new device to the master device to join the point-to-point wireless network is communicated at a normal transmit power level.

13. The method of claim 9, wherein the master device is a slave in the second point-to-point wireless network.

14. The method of claim 9, wherein the master device is a master in the second point-to-point wireless network.

15. The method of claim 9, wherein the master device communicating packet data with the at least one other wireless device of the second point-to-point wireless network on an interspersed basis at normal transmit power levels comprises:

the master device setting its transmit power to a reduced transmit power level;

the master device transmitting at least one data packet to the new device at the reduced power level;

the master device setting its transmit power to a normal transmit power level;

the master device transmitting at least one data packet to a device of the second point-to-point wireless network;

the master device setting its transmit power to a reduced transmit power level; and

the master device transmitting at least one data packet to the new device at the reduced power level.

16. The method of claim 9, wherein the master device and the new device communicating packet data with one another at reduced transmit power levels that are sufficient to maintain radio communications between the devices at the proximate distance in order to authenticate the new device and to add the new device to the first point-to-point wireless network prevents the packet data from being intercepted by eavesdropping point-to-point wireless network devices.

17. The method of claim 9, wherein the point-to-point wireless network operates according to the Bluetooth Specification.

18. The method of claim 9, wherein:

the first point-to-point wireless network is a piconet;

the second point-to-point wireless network is a piconet; and

the first piconet and the second piconet form a scatternet.

19. The method of claim 9, wherein the reduced transmit power level of the master device differs slightly from the reduced transmit power level of the new device.