Localization based on network of wireless nodes

{
  "publication_number": "US2018219869A1",
  "country": "US",
  "kind": "A1",
  "title": "Localization based on network of wireless nodes",
  "abstract": "A wireless node for use in a network of wireless nodes, for performing a localization to determine a location of a mobile device based on respective beacon signals transmitted wirelessly between the mobile device and each of a plurality of the wireless nodes. The first wireless node is configured to: wirelessly transmit or receive the respective beacon signal for use in determining the location of the mobile device; and wirelessly transmit information vouching for one or more others of the wireless nodes as being trusted for use in the localization. This information is transmitted to a device performing the localization (e.g. the mobile device), for use in identifying one or more rogue versions of said wireless nodes.",
  "claims": [
    "1. A first wireless node for use in a network of wireless nodes, for performing a localization to determine a location of a mobile device based on respective beacon signals transmitted wirelessly between the mobile device and each of a plurality of the wireless nodes; the first wireless node being configured to: wirelessly transmit or receive the respective beacon signal for use in determining the location of the mobile device; and wirelessly transmit information vouching for one or more others of the wireless nodes as being trusted for use in said localization, said information being transmitted to a device performing the localization for use in identifying one or more rogue versions of said wireless nodes. 2. The first wireless node of claim 1, comprising a first interface configured to transmit or receive the respective beacon signal on a first wireless channel, and a second interface configured to transmit said information vouching for the other wireless nodes on a second channel; wherein: the second channel is on a different frequency than the first channel, the second channel uses a different radio access technology than the first channel, the second channel uses a different physical medium than the first channel, the second channel requires a line-of-sight while the first channel does not, and/or the second channel has a substantially shorter range than the first channel. 3. The first wireless channel of claim 2, wherein the first channel is a radio channel. 4. The first wireless node of claim 2, wherein at least the first node is incorporated with a respective luminaire and the second channel uses coded light embedded in illumination emitted by the luminaire. 5. The first wireless node of claim 2, wherein the second channel uses a near-field radio technology. 6. The first wireless node of claim 2, wherein the device performing the localization is the mobile device, or the device performing the localization is a location server that receives said information via the mobile device; and, as well as transmitting said information vouching for the one or more other nodes, the first wireless node is further configured to use the second channel to additionally transmit to the mobile device: an identifier of the network to be used to perform the localization; and/or a location of the first wireless node, for verifying said localization, or for obtaining an initial fix of the mobile devices' location before continuing to track the mobile device's location based on said localization. 7. The first wireless node of claim 1, wherein the first wireless node, is configured to transmit said information on a same wireless channel as used to transmit or receive the respective beacon signal. 8. The first wireless node of claim 7, wherein: the first wireless node comprises a first interface configured to transmit or receive the respective beacon signal on a first wireless channel, the information vouching for the one or more other nodes, also being transmitted on the first channel; said information is transmitted by the first wireless node in a form encrypted or signed with a digital signature; the first wireless node comprises a second interface configured to transmit, over a second channel a public key for decrypting the encryption or a certificate for verifying the digital signature, wherein the second channel: is on a different frequency than the first channel, uses a different radio access technology than the first channel, uses a different physical medium than the first channel, requires a line-of-sight while the first channel does not, and/or has a substantially shorter range than the first channel. 9. The first wireless node of claim 1, wherein said information vouches for only subset of the wireless nodes, the subset consisting of those of the wireless nodes that are trusted by the first wireless node and within a predetermined proximity of said first wireless node. 10. The first wireless node of claim 9, wherein the subset comprises only those of the wireless nodes that are trusted and within a predetermined proximity along a predicted navigation path of the mobile device. 11. The first wireless node of claim 1, wherein the device performing the localization is the mobile device which receives said information via a receiver of the mobile device, or the device performing the localization is a location server which receives said information via a second one of said wireless nodes or via the mobile device. 12. A mobile device for use in a network of wireless nodes, for performing a localization to determine a location of the mobile device based on respective beacon signals transmitted wirelessly between the mobile device and each of a plurality of the wireless nodes; the mobile device comprising: one or more wireless interfaces configured to wirelessly transmit or receive the respective beacon signals for use in determining the location of the mobile device, and to wirelessly receive information from a first one of the wireless nodes vouching for one or more others of the wireless nodes as being trusted for use in said localization; a location module configured to perform said localization; and a security module configured to identify one or more rogue versions of said wireless nodes based on said information. 13. A system comprising: a network of wireless nodes, for performing a localization to determine a location of a mobile device based on respective beacon signals transmitted wirelessly between the mobile device and each of a plurality of the wireless nodes; and the mobile device and/or a location server; wherein each of the wireless nodes is configured to wirelessly transmit a respective report vouching for one or more others of the wireless nodes as being trusted for use in said localization; wherein the mobile device is configured to receive one or more of said reports, or the location servers is configured to receive one or more of said reports via at least one receiving one of said wireless nodes or via the mobile device; and wherein the mobile device or location server comprises a location module configured to perform said localization, and a security module configured to identify one or more rogue versions of said wireless nodes based on one or more of said reports. 14. The mobile device of claim 12, wherein the security module is configured to: exclude the identified rogue nodes from use in said localization, or give the signals from the identified rogue nodes a lower weighting in said localization relative to the vouched-for nodes. 15. The mobile device of claim 12, wherein the security module is configured to report the identified rogue nodes to a location server or administrative entity. 16. The system of claim 13, wherein: each of the wireless nodes is configured to transmit or receive the respective beacon signal on a first wireless channel; the system comprises a transmitter configured to transmit, to the mobile device over a second channel, an initial report vouching for an initial group of said wireless nodes, wherein the second channel is on a different frequency than the first channel, uses a different radio access technology than the first channel, uses a different physical medium than the first channel, requires a line-of-sight while the first channel does not, and/or has a substantially shorter range than the first channel; the location module is comprised in the mobile device and the mobile device receives the initial report, or the location module is comprised in the location server and the location server receives the initial report via the mobile device; and the location module is configured to perform one or more instances of said localization including at least a first instance, the first instance of the localization being performed based only on the respective beacon signals of ones of those wireless nodes vouched for in said initial report. 17. The system of claim 13, wherein: each of the wireless nodes is configured to transmit or receive the respective beacon signal on a first wireless channel and the respective reports are also transmitted on the first channel; the respective reports are transmitted by each of the wireless nodes in a form encrypted or signed with a digital signature; and the system comprises a transmitter configured to transmit, to the mobile device over a second channel, a public key for decrypting the encryption or a certificate for verifying the digital signature, wherein the second channel: is on a different frequency than the first channel, uses a different radio access technology than the first channel, uses a different physical medium than the first channel, requires a line-of-sight while the first channel does not, and/or has a substantially shorter range than the first channel; the security module is comprised in the mobile device and the mobile device receives said public key or certificate, or the security module is comprised in the location server and the location server receives the public key or certificate via the mobile device; and the security module is configured to use the received public key to decrypt the encryption, or to use the received certificate to verify the digital signature. 18. The system of claim 16, wherein the transmitter is placed at an entry point to a room, building or zone in which said wireless nodes are disposed, the transmitter being arranged to transmit said initial report and/or said certificate or public key over the second channel to the mobile device upon passing said entry point. 19. A computer program product for performing a localization to determine a location of a mobile device based on measurements of a respective beacon signal transmitted wirelessly between the mobile device and each of a plurality of the wireless nodes in a network of wireless nodes; the computer-program product comprising code embodied on at least one computer-readable medium, and configured so as when retrieved and/or downloaded and executed on one or more processors to perform operations of: receiving information from a first one or the wireless nodes vouching for one or more others of the wireless nodes as being trusted for use in said localization; performing said localization; and identifying one or more rogue versions of said wireless nodes based on said information."
  ],
  "description_excerpt": "The present disclosure relates to the identification of rogue nodes in a network of wireless reference nodes emitting beacon signals used for localization.\n\nIn an indoor positioning system, the location of a wireless device such as a mobile user terminal can be determined with respect to a location network comprising multiple anchor nodes, sometimes also referred to as beacon nodes or reference nodes. These anchors are wireless nodes whose locations are known a priori, typically being recorded in a location database which can be queried to look up the location of a node. The anchor nodes thus act as reference nodes for localization. Measurements are taken of the signals transmitted between the mobile device and a plurality of anchor nodes, for instance the RSSI (receiver signal strength indicator), ToA (time of arrival) and/or AoA (angle of arrival) of the respective signal. Given such a measurement from three or more nodes, the location of the mobile terminal may then be determined relative to the location network using techniques such as trilateration, multilateration or triangulation. Given the relative location of the mobile terminal and the known locations of the anchor nodes, this in turn allows the location of the mobile device to be determined in more absolute terms, e.g. relative to the globe or a map or floorplan.\n\nAnother localization technique is to determine the location of mobile device based on a “fingerprint” of a known environment. The fingerprint comprises a set of data points each corresponding to a respective one of a plurality of locations in the environment in question.",
  "cpc": [
    "H04L 63/107",
    "G01S 1/68",
    "G01S 5/0226",
    "G01S 5/0236",
    "H04L 9/0825",
    "H04W 12/12",
    "H04W 12/122",
    "H04W 4/025",
    "H04W 64/00",
    "H04W 64/003"
  ],
  "ipc": [
    "H04W 12/12",
    "H04L 29/06",
    "H04L 9/08",
    "H04W 4/02",
    "H04W 64/00",
    "G01S 1/68",
    "G01S 5/02",
    "H04W 12/122"
  ],
  "assignees": [
    "Philips Lighting Holding BV"
  ],
  "inventors": [
    "Sandeep Shankaran Kumar",
    "Ashish Vijay Pandharipande"
  ],
  "filing_date": "2015-06-09",
  "publication_date": "2018-08-02",
  "priority_date": "2014-06-13",
  "application_number": "US-201515318454-A",
  "family_id": "50942132",
  "cited_by_count": 41,
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