APPROACH TO SECURE LOCALIZATION IN WIRELESS NETWORKS

• US 20090186602A1
• Filed: 08/21/2008
• Published: 07/23/2009
• Est. Priority Date: 01/23/2008
• Status: Active Grant

• Current Assignee: Telcordia Legacy Inc.
• Original Assignee: Telcordia Technologies Incorporated (Telefonaktiebolaget LM Ericsson), Toshiba Corporation
• Inventors: Kaul, Vikram, Famolari, David, Ghosh, Abhrajit
• Granted Patent: US 8,145,236 B2
• Time in Patent Office: Days
• US Class Current: 455/412.100
• CPC Class Codes: G01S 5/011 Identifying the radio environment
• CPC Class Codes: H04L 51/58 Message adaptation for wireless communication
• CPC Class Codes: H04W 12/02 Protecting privacy or anonymity, e.g. protecting personally identifiable information [PII]
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Embodiments of the present invention disclose a secure localization infrastructure using transmitters that can transmit messages at multiple distinct power levels throughout a community of reference points. Transmitters send messages at different power levels in a manner that every location in the system corresponds to a unique set of messages. Received messages are reported back to the localization infrastructure, which then determines location by comparing the messages reported.

Claims

1. A secure localization system, comprising:

at least one secure message transmitter (SMT) for transmitting secure messages (SMs) using multiple transmission power levels, the SMs comprising a set of identifiers comprising identifiers for the SMT transmitting the message and power level used for transmission, and an identifier for each SM itself;

a plurality of reference points (RPs) deployed at known locations; and

a localization controller configured to instruct each SMT to transmit SMs at specific power levels for receipt at the RPs,

wherein each RP is configured to receive SMs and report the received SMs to the localization controller, each report containing an identifier for the RP in addition to the SM received by it, the localization controller being further configured to determine location by comparing reports received.

2. The secure localization system of claim 1, wherein the at least one SMT is configured to transmit a plurality of SMs at the same power level.

3. The secure localization system of claim 1, wherein each SMT comprises an encryptor for encrypting SMs.

4. The secure localization system of claim 3, wherein the encryptor is configured to encrypt SMT and power level identifiers.

5. The secure localization system of claim 1, wherein the SMT and power level identifiers are encrypted within the SM.

6. The secure localization system of claim 1, wherein the secure messages further comprise a random number.

7. The secure localization system of claim 1, wherein the localization controller comprises a random number generator.

8. The secure localization system of claim 1, wherein each RP is configured to receive SMs from all SMTs.

9. A method for secure localization, the method comprising:

iteratively selecting each of a set of transmission power levels at one or more secure message transmitters (SMTs);

generating secure messages (SMs) at one or more of the SMTs, the SMs comprising a set of identifiers comprising identifiers for the SMT transmitting the message and power level used for transmission, and an identifier for each SM itself;

requesting each SMT to transmit a specific number of SMs at selected power levels;

responsive to the request, transmitting the specific number of SMs at the specified power level to a plurality of reference points (RPs) deployed at known locations;

for every RP that receives an SM, reporting the received SM to a localization controller, each report containing an identifier for the RP in addition to the SM received by it; and

determining location by comparing reports received.

10. The method of claim 9, wherein the determining step occurs at the localization controller.

11. The method of claim 9, wherein the determining step occurs at the SMT.

12. The method of claim 9, further comprising:

encrypting each SM.

13. The method of claim 12, wherein the encrypting step comprises encrypting the SM itself.

14. The method of claim 12, wherein the encrypting step comprises encrypting the set of identifiers within the SM as well as the SM itself.

15. The method of claim 9, further comprising:

generating a random number for inclusion within an SM.

16. The method of claim 15, further comprising:

maintaining a record of the last generated random number, the number being associated with a particular SMT identifier, power level identifier and SM identifier.

17. The method of claim 9, further comprising:

transmitting SMs to a client;

responsive to receipt of the SMs, reporting the received SMs to the localization controller; and

determining location of client.

18. The method of claim 17, wherein the determining step comprises estimating the RPs nearest the client and comparing the SMs reported by the client with those reported by the nearest estimated RPs.

19. The method of claim 17, wherein the determining step occurs at the localization controller.

20. The method of claim 17, wherein the determining step occurs at the SMT.

21. A localization controller, comprising:

a processor configured to instruct at least one secure message transmitter (SMT) to transmit secure messages (SMs) at a specific power level to a plurality of reference points (RPs) deployed at known locations throughout a localization area, the SMs comprising a set of identifiers comprising identifiers for the SMT transmitting the SMs and power level used for transmission, and an identifier for each SM itself, the processor being further configured to receive SM reports transmitted by the RPs,

wherein location can be determined by comparing the SM reports received.

22. The localization controller of claim 21, further comprising:

a random number generator for generating random numbers for inclusion within the SMs; and

a data structure for storing data associated with the SMs.

23. The localization controller of claim 22, wherein the data comprises random numbers generated for a particular SMT, power level and SM identifier set.

24. The localization controller of claim 21, wherein the processor is further configured to receive reports transmitted from a client responsive to SMs transmitted to the client and estimate the RPs nearest the client, wherein client positioning can be determined by comparing SMs reported by the RPs with the SM reports transmitted by the client.