Implicit Spatial Replay Protection

• US 20200137677A1
• Filed: 12/27/2019
• Published: 04/30/2020
• Est. Priority Date: 01/25/2016
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Ben Henda, Noamen, Lehtovirta, Vesa, Pfeffer, Katharina, Sultana, Shabnam, Torvinen, Vesa, Wifvesson, Monica
• Granted Patent: US 10,880,681 B2
• Time in Patent Office: Days
• CPC Class Codes: H04W 12/106 Packet or message integrity
• CPC Class Codes: H04W 4/021 Services related to particular areas, e.g. point of interest [POI] services, venue services or geofences
• CPC Class Codes: H04W 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
• CPC Class Codes: H04W 4/029 Location-based management or tracking services
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 76/14 Direct-mode setup

Abstract

A terminal device obtains grid location information relating to a cell of a predetermined grid in which the terminal device is located. The terminal device then calculates a message integrity code based on the grid location information and transmits a proximity service discovery message. The discovery message includes the calculated message integrity code and does not include the grid location information. A second terminal device receives the proximity service discovery message. The second terminal device then obtains grid location information relating to at least one cell of a predetermined grid within a predetermined distance of a location of the second terminal device, calculates at least one message integrity code based on the grid location information, and determines whether a calculated message integrity code matches the message integrity code in the received discovery message. The second terminal device then acts on the received discovery message only if there is a match.

Claims

1. A method of operation of a terminal device, the method comprising:

obtaining grid location information relating to a cell of a predetermined grid in which the terminal device is located;

calculating a message integrity code based on the grid location information; and

transmitting a proximity service discovery message, wherein the discovery message includes the calculated message integrity code and does not include the grid location information.

2. The method of claim 1, wherein obtaining the grid location information comprises:

obtaining global navigation satellite system (GLASS) data relating to a location of the terminal device; and

identifying the cell of the predetermined grid in which the terminal device is located.

3. The method of to claim 1, wherein the predetermined grid comprises cells having linear dimensions approximately equal to a range of a proximity service to which the proximity service discovery message relates.

4. The method of claim 1, wherein the predetermined grid comprises square cells, each having side lengths equal to double the range of a proximity service to which the proximity service discovery message relates.

5. The method of claim 1, wherein the memory further contains instructions executable by the processor circuit, such that the terminal device is operable to calculate the message integrity code based also on a payload of the proximity service discovery message.

6. The method of claim 1, wherein the memory further contains instructions executable by the processor circuit, such that the terminal device is operable to receive information about the predetermined grid from a network node.

14. The non-transitory computer-readable medium of claim 3, wherein the instructions cause the terminal device to obtain the grid location information by:

obtaining global navigation satellite system (GNSS) data relating to a location of the terminal device; and

identifying the cell of the predetermined grid in which the terminal device is located.

7. A terminal device for use in a communications network, the terminal device comprising a processor circuit, and a memory, the memory containing instructions executable by the processor circuit, such that the terminal device is operable to:

obtain grid location information relating to a cell of a predetermined grid in which the terminal device is located;

calculate a message integrity code based on the grid location information; and

transmit a proximity service discovery message, wherein the discovery message includes the calculated message integrity code and does not include the grid location information.

8. The terminal device of claim 7, wherein the memory further contains instructions executable by the processor circuit, such that the terminal device is operable to obtain the grid location information by:

obtaining global navigation satellite system (GNSS) data relating to a location of the terminal device; and

identifying the cell of the predetermined grid in which the terminal device is located.

9. The terminal device of claim 7, wherein the predetermined grid comprises cells having linear dimensions approximately equal to a range of a proximity service to which the proximity service discovery message relates.

11. The terminal device of claim 7, wherein the memory further contains instructions executable by the processor circuit, such that the terminal device is operable to calculate the message integrity code based also on a payload of the proximity service discovery message.

12. The terminal device of claim 7, wherein the memory further contains instructions executable by the processor circuit, such that the terminal device is operable to receive information about the predetermined grid from a network node.

10. The terminal device of claim wherein the predetermined grid comprises square cells, each having side lengths equal to double the range of a proximity service to which the proximity service discovery message relates.

13. A non-transitory computer-readable medium having stored thereon instructions that, when executed by a processor circuit of a terminal device, cause the terminal device to:

obtain grid location information relating to a cell of a predetermined grid in which the terminal device is located;

calculate a message integrity code based on the grid location information; and

transmit a proximity service discovery message, wherein the discovery message includes the calculated message integrity code and does not include the grid location information.

15. The non-transitory computer-readable medium of claim 13, wherein the predetermined grid comprises cells having linear dimensions approximately equal to a range of a proximity service to which the proximity service discovery message relates.

16. The non-transitory computer-readable medium of claim 15, wherein the predetermined grid comprises square cells, each having side lengths equal to double the range of a proximity service to which the proximity service discovery message relates.

17. The non-transitory computer-readable medium of claim 13, wherein the instructions cause the terminal device to calculate the message integrity code based also on a payload of the proximity service discovery message.

18. The non-transitory computer-readable medium of claim 13, wherein the instructions cause the terminal device to receive information about the predetermined grid from a network node.