VERIFYING GENERIC BROADCAST OF LOCATION ASSISTANCE DATA

• US 20130223626A1
• Filed: 08/29/2012
• Published: 08/29/2013
• Est. Priority Date: 08/30/2011
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: EDGE, Stephen William, Fischer, Sven, Hawkes, Philip Michael
• Granted Patent: US 9,271,256 B2
• Time in Patent Office: Days
• US Class Current: 380/270
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 2209/80 Wireless
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32
• CPC Class Codes: H04L 9/0637 Modes of operation, e.g. cipher block chaining [CBC], electronic codebook [ECB] or Galois/counter mode [GCM]
• CPC Class Codes: H04L 9/3249 using RSA or related signature schemes, e.g. Rabin scheme
• CPC Class Codes: H04W 12/033 of the user plane, e.g. user's traffic
• CPC Class Codes: H04W 12/04 Key management, e.g. using generic bootstrapping architecture [GBA]
• CPC Class Codes: H04W 12/10 Integrity
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 4/20 Services signaling; Auxiliary data signalling, i.e. transmitting data via a non-traffic channel
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Various techniques are provided for Location Services (LCS) Assistance Data broadcast, for example for implementation in LTE and LTE-A systems. The embodiments described herein may use the LPP/LPPe positioning protocol, by making use of existing unsolicited Provide Assistance Data (PAD) messages. Embodiments avoid the need to define and implement a separate broadcast Assistance Data protocol. Additional exemplary embodiments for scheduling and verifying of the broadcast Assistance Data messages are described herein.

Claims

1. A method for verifying a broadcast message, the method comprising:

receiving a broadcast message, at a device, from a Location Server wherein the broadcast message comprises Assistance Data (AD) for location services and a plurality of broadcast control parameters; and

verifying a validity of the AD using at least one control parameter from the plurality of broadcast control parameters received from the Location Server.

2. The method of claim 1, further comprising receiving information associated with the broadcast at the device from the Location Server, wherein the information associated with the broadcast is received point to point using a positioning protocol, and wherein verifying the validity of the AD uses the information received point to point.

3. The method of claim 2, wherein verifying the validity of the AD comprises:

determining that the device is configured to require digitally signed broadcast messages based on the information associated with the broadcast received point to point;

determining that the broadcast message is not digitally signed; and

discarding the broadcast message, in response to determining that the broadcast message is not digitally signed.

4. The method of claim 1, wherein verifying the validity of the AD comprises:

determining that the broadcast message is not a duplicate message by checking at least one parameter from the plurality of broadcast control parameters that indicates a uniqueness of the broadcast message for at least a predefined period of time.

5. The method of claim 1, wherein verifying the validity of the AD comprises:

determining applicability of the broadcast message based on a time indicator from the plurality of broadcast control parameters, wherein the device uses the time indicator in determining if the validity of the AD has yet to occur or has already expired.

6. The method of claim 1, wherein verifying the validity of the AD comprises:

determining applicability of the broadcast message based on a geographic area indicator from the plurality of broadcast control parameters, wherein the device uses the geographic area indicator in determining if the broadcast message is valid for the device based on the device'"'"'s location.

7. The method of claim 1, wherein verifying the validity of the AD comprises:

determining that the broadcast message comprises at least one type of AD that is needed by the device.

8. The method of claim 1, wherein verifying the validity of the AD comprises:

determining that the broadcast message is digitally signed;

in response to determining that the broadcast message is digitally signed, determining that the device has at least one key to perform authentication verification for the digitally signed broadcast message; and

verifying the validity of the broadcast message by verifying a digital signature for the broadcast message using the at least one key.

9. The method of claim 8, wherein the broadcast message is encapsulated.

10. The method of claim 8, wherein the broadcast message is digitally signed using asymmetric cryptography.

11. The method of claim 8, wherein the device begins the authentication verification for the digitally signed broadcast message before receiving the entire broadcast message by identifying the at least one key by using a public key identifier from the digital signature that appears at the beginning of the broadcast message.

12. The method of claim 8, wherein verifying the digital signature comprises:

converting the digital signature for the broadcast message using the at least one key; and

comparing a representation of the broadcast message against the converted digital signature; and

determining that the broadcast message is authentic if the converted digital signature is the same as the representation of the broadcast message.

13. The method of claim 12, wherein the representation of the broadcast message is a Secure Hash Algorithm (SHA) based hash.

14. The method of claim 1, further comprising:

determining that the broadcast message is ciphered;

in response to determining that the broadcast message is ciphered, determining that the device has at least one key to decipher the ciphered broadcast message; and

deciphering the broadcast message using the at least one key.

15. The method of claim 14, wherein the AD is ciphered using symmetric cryptography.

16. The method of claim 14, wherein determining that the device has the at least one key to decipher the ciphered broadcast message comprises using a cipher Key ID contained in the at least one control parameter that indicates the at least one key that should be used in deciphering the broadcast message.

17. The method of claim 14, wherein the broadcast message is encapsulated.

18. The method of claim 14, wherein deciphering the AD from the broadcast message further comprises using a counter from the plurality of broadcast control parameters.

19. The method of claim 18, wherein another counter for a subsequent broadcast message is derived using the counter from the current broadcast message.

20. The method of claim 14, wherein an initial counter is received from the Location Server at the device in two portions.

21. The method of claim 20, further comprising receiving information associated with the broadcast, wherein the information associated with the broadcast is received point to point at the device from at the device from the Location Server using a positioning protocol, wherein the information associated with the broadcast received point to point from the Location Server contains a first portion of the initial counter along with a ciphering key and an identifier for the first portion of the initial counter and the ciphering key.

22. The method of claim 20, wherein a second portion of the initial counter is derived from at least a counter from the plurality of broadcast control parameters.

23. The method of claim 20, wherein if the broadcast message is an initial broadcast message, deriving the initial counter comprises:

receiving a first portion of an initial key using point-to-point mode;

receiving a second portion of the initial key using broadcast mode; and

deriving the initial counter using the first portion and the second portion.

24. The method of claim 1, further comprising:

at least temporarily ceasing the use of a broadcast system associated with the broadcast message if a plurality of broadcast messages fail during the verification process.

25. The method of claim 1, wherein the broadcast message is an LTE Positioning Protocol (LPP) message or an LPP/LPP Extensions (LPPe) Provide Assistance Data message.

26. A device, comprising:

a transceiver configured to;

receive a broadcast message from a Location Server wherein the broadcast message comprises Assistance Data (AD) for location services and a plurality of broadcast control parameters; and

a processor configured to;

verify a validity of the AD using at least one control parameter from the plurality of broadcast control parameters received from the Location Server.

27. The device of claim 26, wherein the transceiver is further configured to receive information associated with the broadcast at the device from the Location Server, wherein the information associated with the broadcast is received point to point using a positioning protocol, and wherein verifying the validity of the AD uses the information received point to point.

28. The device of claim 27, wherein verifying the validity of the AD comprises:

determining, by the processor, that the device is configured to require digitally signed broadcast messages based on the information associated with the broadcast received point to point;

determining, by the processor, that the broadcast message is not digitally signed; and

discarding the broadcast message, in response to determining that the broadcast message is not digitally signed.

29. The device of claim 26, wherein verifying the validity of the AD comprises:

determining, by the processor, that the broadcast message is not a duplicate message by checking at least one parameter from the plurality of broadcast control parameters that indicates a uniqueness of the broadcast message for at least a predefined period of time.

30. The device of claim 26, wherein verifying the validity of the AD comprises:

determining applicability of the broadcast message, by the processor, based on a time indicator from the plurality of broadcast control parameters, wherein the device uses the time indicator in determining if the validity of the AD has yet to occur or has already expired.

31. The device of claim 26, wherein verifying the validity of the AD comprises:

determining applicability of the broadcast message, by the processor, based on a geographic area indicator from the plurality of broadcast control parameters, wherein the device uses the geographic area indicator in determining if the broadcast message is valid for the device based on the device'"'"'s location.

32. The device of claim 26, wherein verifying the validity of the AD comprises:

determining that the broadcast message comprises at least one type of AD that is needed by the device.

33. The device of claim 26, wherein the processor is configured to:

determine that the broadcast message is digitally signed;

in response to determining that the broadcast message is digitally signed, determine that the device has at least one key to perform authentication verification for the digitally signed broadcast message; and

verify the validity of the broadcast message by verifying a digital signature for the broadcast message using the at least one key.

34. The device of claim 33, wherein the broadcast message is encapsulated.

35. The device of claim 33, wherein the processor begins the authentication verification for the digitally signed broadcast message before the transceiver receives the entire broadcast message by identifying the at least one key by using a public key identifier from the digital signature that appears at the beginning of the broadcast message.

36. The device of claim 33, wherein verifying the digital signature comprises:

converting, by the processor, the digital signature for the broadcast message using the at least one key; and

comparing, by the processor, a representation of the broadcast message against the converted digital signature; and

determining, by the processor, that the broadcast message is authentic if the converted digital signature is the same as the representation of the broadcast message.

37. The device of claim 26, wherein the processor is further configured to:

determine that the broadcast message is ciphered;

in response to determining that the broadcast message is ciphered, determine that the device has at least one key to decipher the ciphered broadcast message; and

decipher the broadcast message using the at least one key.

38. The device of claim 37, wherein determining that the device has the at least one key to decipher the ciphered broadcast message comprises using a cipher Key ID contained in the at least one control parameter that indicates the at least one key that should be used in deciphering the broadcast message.

39. The device of claim 37, wherein deciphering the AD from the broadcast message further comprises using a counter from the plurality of broadcast control parameters.

40. The device of claim 39, wherein another counter for a subsequent broadcast message is derived using the counter from the current broadcast message.

41. The device of claim 37 wherein an initial counter is received by the device from the Location Server in two portions.

42. The device of claim 41, wherein the transceiver is further configured to receive information associated with the broadcast from the Location Server, the information being received point to point using a positioning protocol, and wherein the information associated with the broadcast received point to point from the Location Server contains a first portion of the initial counter along with a ciphering key and an identifier for the first portion of the initial counter and the ciphering key.

43. The device of claim 41, wherein a second portion of the initial counter is derived from at least a counter from the plurality of broadcast control parameters.

44. The device of claim 41, wherein if the broadcast message is an initial broadcast message, deriving the initial counter comprises:

receiving, by the transceiver, a first portion of an initial key using point-to-point mode;

receiving, by the transceiver, a second portion of the initial key using broadcast mode; and

deriving, by the processor, the initial counter using the first portion and the second portion.

45. The device of claim 26, wherein the transceiver is configured to:

at least temporarily cease the use of a broadcast system associated with the broadcast message if a plurality of broadcast messages fail during the verification process.

46. The device of claim 26, wherein the broadcast message is an LTE Positioning Protocol (LPP) message or an LPP/LPP Extensions (LPPe) Provide Assistance Data message.

47. A non-transitory computer readable storage medium, wherein the non-transitory computer readable storage medium comprises instructions executable by a processor, the instructions comprising instructions to:

receive a broadcast message, at a device, from a Location Server wherein the broadcast message comprises Assistance Data (AD) for location services and a plurality of broadcast control parameters; and

verify a validity of the AD using at least one control parameter from the plurality of broadcast control parameters received from the Location Server.

48. A device, comprising:

means for receiving a broadcast message from a Location Server wherein the broadcast message comprises Assistance Data (AD) for location services and a plurality of broadcast control parameters; and

means for verifying a validity of the AD using at least one control parameter from the plurality of broadcast control parameters received from the Location Server.