Methods and devices for sending and receiving location information for wireless devices

Patent metadata

Field	Value
Publication number	US-9883324-B2
Application number	US-201113388579-A
Country	US
Kind code	B2
Filing date	Dec 20, 2011
Priority date	Dec 20, 2011
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

The embodiments herein relate to a method in a first device ( 101 ) for informing a second device ( 105 ) that an identity associated with the first device ( 101 ) is at a certain location. The first device ( 101 ) obtains information about the location of the first device ( 101 ). The first device ( 101 ) broadcasts, by means of device to device, D2D, communication, a message to be received by the second device ( 105 ). The message comprises the location information and an identity information associated with a user of the first device ( 101 ). The location information is transmitted on a first communications resource and the identity information is transmitted on a second communications resource.

First claim

The invention claimed is:

1. A method in a first device for informing a second device that an identity associated with the first device is at a certain location, the method comprising:
obtaining information about the location of the first device;
determining a second communications resource using a hash function, wherein the hash function has as input an identifier of a first communications resource; and
broadcasting, via a device to device (D2D) communication, a message to be received by the second device, wherein the message includes the location information and identity information that identifies a user of the first device, and wherein the identity information is transmitted on the first communications resource and the location information is transmitted on the second communications resource.

2. The method of claim 1 , further comprising:
obtaining a number of data bits based on a coverage distance of the broadcasting of the message and based on a predefined precision of the location information; and
truncating the location information to the obtained number of bits by discarding one or more most significant bits of the location information until the truncated location information has the obtained number of bits; and
wherein the location information comprised in the message is the truncated location information.

3. The method of claim 2 , wherein the number of data bits is predefined in the first device.

4. The method of claim 1 , wherein the obtained location information is associated with a reference known to the first device and the second device.

5. The method of claim 4 , wherein the reference is associated with a global positioning system, referred to as GPS, a local coordinate system or a global coordinate system.

6. The method of claim 1 , further comprising:
identifying an amount of available communications resources for the broadcasting of the message; and
determining that the location information should be included in the message only when the identified amount of available communications resources is above a threshold.

7. The method of claim 1 , further comprising:
determining that the location information should be encrypted such that it can be decrypted by the second device;
encrypting the location information by using an encryption key known to the first device; and
wherein the location information included in the message is the encrypted location information.

8. The method of claim 1 , wherein the first communications resource comprises an indication indicating that the message includes the location information.

9. The method of claim 1 , wherein the first communications resource and the second communications resource are the same communications resource.

10. The method of claim 1 , wherein the first communications resource and the second communications resource are different communications resources.

11. The method of claim 1 , wherein the hash function is a hash function of both the identity information and the first communications resource.

12. The method of claim 11 , wherein the first communications resource used to determine the second communications resource corresponds to at least one of an area in a time-frequency grid, a code, and a time slot of spectrum used by the first communication resource.

13. A method in a second device for being informed by a first device that an identity associated with the first device is at a certain location, the method comprising:
receiving, via a device to device (D2D) communication, a first portion of a message broadcast from the first device, wherein the first portion of the message includes identity information that identifies a user of the first device, wherein the identity information is received on a first communications resource;
determining the second communications resource using a hash function, wherein the hash function has as input an identifier of the first communications resource;
identifying that the location information is mapped to the determined second communications resource; and
receiving, via a device to device (D2D) communication, a second portion of the message broadcast from the first device, wherein the second portion of the message includes information about the location of the first device, wherein the location information is received on the second communications resource.

14. The method of claim 13 , further comprising
detecting that the message includes the location information.

15. The method of claim 14 , wherein the detecting that the message includes the location information further comprises:
detecting an indication indicating that the message includes the location information, wherein the indication is comprised in the first communications resource.

16. The method of claim 13 , wherein the location information in the message is encrypted by the first device using an encryption key known to the first device, and wherein the method further comprises decrypting the location information using a decryption key associated with the encryption key.

17. The method of claim 13 , wherein the location information included in the message is truncated based on a coverage distance of the broadcasting of the message and a predefined precision of the location information, said truncated location information having most significant bits of original location information omitted.

18. The method of claim 13 , wherein the location information is associated with a reference predefined in the second device and the first device.

19. The method of claim 18 , wherein the reference is associated with a global positioning system, referred to as GPS, a local coordinate system or a global coordinate system.

20. The method of claim 18 , further comprising:
identifying the reference with which the location information is associated; and
detruncating the truncated location information, based on the identified reference, by adding most significant bits to the truncated location information.

21. The method of claim 13 , wherein the first communications resource and the second communications resource are the same communications resource.

22. The method of claim 13 , wherein the hash function is a hash function of both the identity information and the first communications resource.

23. A first device for informing a second device that an identity associated
with the first device is at a certain location, the first device comprising:
an obtaining unit configured to obtain information about the location of the first device;
a determining unit configured to determine a second communications resource using a hash function, wherein the hash function has as input an identifier of a first communications resource; and
a broadcasting unit configured to broadcast via a device to device (D2D) communication, a message to be received by the second device, wherein the message includes the location information and identity information that identifies a user of the first device, and wherein the identity information is transmitted on the first communications resource and the location information is transmitted on the second communications resource.

24. The first device of claim 23 , wherein the obtaining unit is further configured to obtain a number of data bits based on a coverage distance of the message and a predefined precision of the location information; and wherein the first device further comprises:
a truncating unit configured to truncate the location inform

Assignees

• Selén Yngve
• Dahlman Erik
• Parkvall Stefan
• Ringström Markus
• ERICSSON TELEFON AB L M (publ)

Inventors

• Selén Yngve
• Dahlman Erik
• Parkvall Stefan
• Ringström Markus

Classifications

• H04W4/008 Primary

  Electricity · mapped topic

• H04W84/18

  Self-organising networks, e.g. ad-hoc networks or sensor networks · CPC title

• H04L63/0428

  wherein the data content is protected, e.g. by encrypting or encapsulating the payload · CPC title

• H04W4/02 Primary

  Services making use of location information · CPC title

• H04W4/06

  Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services · CPC title