WIRELESS NETWORK WITH ENHANCED SECURITY BY REAL-TIME IDENTIFICATION OF A LOCATION OF A RECEIVED PACKET SOURCE

• US 20090017839A1
• Filed: 07/11/2007
• Published: 01/15/2009
• Est. Priority Date: 07/11/2007
• Status: Abandoned Application

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Kim, Kyung-Hyun
• Application Number:
  US11/776,384
• Publication Number:
  US 20090017839A1
• Time in Patent Office: Days
• US Class Current: 455/456.100
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources
• CPC Class Codes: H04L 63/107 wherein the security policies are location-dependent, e.g. entities privileges depend on current location or allowing specific operations only from locally connected terminals
• CPC Class Codes: H04W 12/082 using revocation of authorisation
• CPC Class Codes: H04W 12/088 using filters or firewalls
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Methods, systems, and apparatuses for tracking client devices in a wireless communications network are provided. A bit sequence is received at three or more access points of the wireless communications network from a client device communicatively coupled to the wireless communications network. A physical location of the client device is determined based on a timing of receiving the bit sequence at the three or more access points. The determined physical location may be used to improve security with regard to the client device. If the determined physical location is outside of an acceptable area for the client device, the client device may be decoupled from the communications network and/or other security measures may be taken. In a further aspect, the client device may itself determine its physical location, and transmit an indication of its determined physical location in communication packets used to communicate with the network, for enhanced security.

Claims

1. A method for tracking client devices in a wireless communications network, comprising:

receiving a bit sequence at three or more access points of the wireless communications network from a client device communicatively coupled to the wireless communications network; and

determining a physical location of the client device based on a timing of receiving the bit sequence at the three or more access points.

2. The method of claim 1, further comprising:

determining whether the determined physical location is outside a region authorized for operation of the client device.

3. The method of claim 2, further comprising:

decoupling the client device from the wireless communications network if the determined physical location is determined to be outside the region.

4. The method of claim 1, further comprising:

enabling the client device to communicatively couple to the wireless communications network;

synchronizing a clock of the client device with a clock of the wireless communications network; and

providing a seed value to the client device for generation of the bit sequence.

5. The method of claim 4, wherein said determining a physical location of the client device based on a timing of said receiving the bit sequence at the three or more access points comprises:

generating a local version of the bit sequence at each access point of the three or more access points timed according to a network clock signal synchronized with the clock of the client device;

determining three or more time delays by determining an offset between bits of the bit sequence received from the client device and bits of the local version of the bit sequence generated at each access point of the three or more access points;

determining three or more radial distances by determining a radial distance for each of the determined three or more time delays; and

determining the physical location of the client device based on the determined three or more radial distances.

6. The method of claim 5, wherein said determining the physical location of the client device based on the determined three or more radial distances comprises:

using triangulation to calculate the physical location of the client device based on the determined three or more radial distances.

7. The method of claim 1, further comprising:

receiving a physical location indication from the client device; and

determining whether the received physical location indication and the determined physical location match to validate a communication packet received from the client device.

8. The method of claim 7, further comprising:

rejecting the communication packet if the received physical location indication does not match the determined physical location.

9. A wireless communications network, comprising:

a plurality of access points configured to enable client devices to communicate over the network; and

a location determiner module configured to determine a physical location of a client device communicatively coupled to the network based on a timing of receipt of a bit sequence from the client device at three or more access points of the plurality of access points.

10. The network of claim 9, further comprising:

a security module configured to determine whether the determined physical location is outside a region authorized for operation of the client device, and to cause the client device to be decoupled from the wireless communications network if the determined physical location is determined to be outside the region.

11. The network of claim 9, further comprising:

a clock synchronization module configured to synchronize a clock of the client device with a clock of the wireless communications network; and

a seed value generator configured to generate a seed value for the client device to use to generate the bit sequence.

12. The network of claim 11, wherein a local version of the bit sequence is generated at each access point of the three or more access points timed according to the clock of the wireless communications network;

wherein an offset between bits of the bit sequence received from the client device and bits of the local version of the bit sequence generated at each access point of the three or more access points is determined to determine three or more time delays;

wherein the location determiner module is configured to determine a radial distance for each of the determined three or more time delays to determine three or more radial distances; and

wherein the location determiner module is configured to determine the physical location of the client device based on the determined three or more radial distances.

13. The network of claim 12, wherein the location determiner module is configured to use triangulation to calculate the physical location of the client device based on the determined three or more radial distances.

14. The network of claim 9, further comprising:

a security module configured to determine whether a physical location indication received from the client device matches the determined physical location to validate a communication packet received from the client device.

15. The network of claim 14, wherein the communication packet is rejected if the security module determines the received physical location indication does not match the determined physical location.

16. The network of claim 9, wherein the wireless communications network is an IEEE 802.11 standard wireless local area network.

17. A method in a client device for communicating with a wireless communication network, comprising:

generating a local clock signal synchronized with a clock signal of the network;

generating a bit of a pseudo random bit sequence;

transmitting the generated bit at a predetermined value of the local clock signal; and

repeating generating a bit of the pseudo random bit sequence and transmitting the generated bit at a predetermined value of the local clock signal;

whereby a plurality of access points of the wireless communications network are configured to receive transmitted bits of the pseudo random bit sequence and to determine a physical location of the client device based on a timing of receipt of the transmitted bits.

18. The method of claim 17, further comprising:

generating the pseudo random bit sequence based on a seed bit sequence received from an access point of the wireless communication network.

19. The method of claim 17, further comprising;

receiving bits of a plurality of pseudo random bit sequences from access points in the wireless communications network; and

determining a physical location of the client device based on a timing of receiving the bits of the plurality of pseudo random bit sequences.

20. The method of claim 19, further comprising:

transmitting a communication packet that includes an indication of the generated physical location.

21. A device, comprising:

a radio frequency (RF) communication module configured to enable wireless communications over a wireless communications network;

a clock generator configured to generate a local clock signal synchronized with a network clock signal; and

a pseudo random bit sequence generator configured to generate bits of a pseudo random bit sequence;

wherein the RF communication module is configured to transmit bits of the generated bits at predetermined values of the local clock signal;

whereby a plurality of access points of the wireless communications network are configured to receive the transmitted bits and to determine a physical location of the device based on a timing of receipt of the transmitted bits.

22. The device of claim 21, wherein the pseudo random bit sequence generator is configured to generate the bits of the pseudo random bit sequence based on a seed bit sequence received from an access point of the wireless communication network, wherein the device further comprises:

storage configured to store the seed bit sequence.

23. The device of claim 22, wherein a plurality of pseudo random bit sequences are received from access points in the wireless communications network, wherein the device further comprises:

a location determiner module configured to determine a physical location of the device based on a timing of receiving bits of the plurality of pseudo random bit sequences.

24. The device of claim 23, wherein the RF communication module is configured to transmit a communication packet that includes an indication of the generated physical location.

25. The device of claim 21, wherein the device is an integrated circuit chip.

26. The device of claim 21, wherein the wireless communications network is an IEEE 802.11 standard wireless local area network.