# US 9,520,939 B2 · Methods and apparatus for using visible light communications for controlling access to an area > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,520,939 B2 - Document ID: US9520939B2 - Status: Granted - Kind: B2 - Application number: 13/787,676 - Filed: 2013-03-06 - Published: 2014-09-11 - Granted: 2016-12-13 - Earliest claimed: 2013-03-06 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Aleksandar Jovicic; Ivan Klimek; Thomas Joseph Richardson; Junyi Li - Web page: https://patentgrep.com/patent/US9520939B2 ## CPC - H04B 10/116: Visible light communication - G07C 9/00309: {operated with bidirectional data transmission between data carrier and locks} - G07C 9/00571: {operated by interacting with a central unit} - H04K 1/00: Secret communication - G07C 2009/00785: {by light} - H04B: TRANSMISSION - G07C: TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE - H04K: SECRET COMMUNICATION; JAMMING OF COMMUNICATION ## Abstract Methods and apparatus for controlling access to secure areas are described. Time varying values are generated from access device identifiers, e.g., door identifiers. The time varying value, e.g., a hashed door identifier value, is transmitted as a VLC signal by a luminaire near the door to which the hashed identifier corresponds. A mobile detects the transmitted hashed door identifier value and sends an access request via a wireless signal, e.g., a radio signal. The access request includes a value generated from the received hashed door identifier and a mobile device identifier. A control device determines, from information in the access request and stored information indicating which mobile devices have authority to access which doors, if access should be granted to the door corresponding to the hashed access device identifier from which the received information was generated. The received information may be hash of the mobile identifier and hashed door identifier. ## Claims ### Claim 1 A method of operating an access authorization device, said method comprising: storing a plurality of unique identifiers corresponding to mobile wireless communications devices authorized to control an access device used to control access to an area; providing identification information corresponding to said access device to a light emitting device by way of a power line network; receiving a first hashed value from a mobile wireless communications device, said first hashed value having been generated from said identification information corresponding to said access device and a unique identifier corresponding to said mobile wireless communications device seeking to trigger unlocking of said access device; receiving, from said mobile wireless communications device, said unique identifier corresponding to said mobile wireless communications device; generating a second hashed value by hashing said unique identifier corresponding to said mobile wireless communications device with said identification information corresponding to said access device; determining if said first hashed value was generated from one of said mobile wireless communications devices authorized to control said access device based at least in part on determining if said second hashed value matches said first hashed value; and sending an access command for unlocking said access device after determining that said first hashed value was generated from one of said mobile wireless communications devices authorized to control said access device. ### Claim 2 (depends on 1) The method of claim 1, further comprising: denying access to said area after determining that said first hashed value was not generated from one of said plurality of unique identifiers corresponding to mobile wireless communications devices authorized to control said access device and said identification information corresponding to said access device. ### Claim 3 (depends on 2) The method of claim 2, further comprising: generating an alert indicating an unauthorized access attempt after determining that said first hashed value was not generated from one of said plurality of unique identifiers corresponding to mobile wireless communications devices authorized to control said access device and said identification information corresponding to said access device. ### Claim 4 (depends on 1) The method of claim 1, further comprising: generating said identification information corresponding to said access device by hashing an identifier corresponding to said access device with a time varying value. ### Claim 5 An access authorization device, comprising: means for storing a plurality of unique identifiers corresponding to mobile wireless communications devices authorized to control an access device used to control access to an area; means for providing identification information corresponding to said access device to a light emitting device by way of a power line network; means for receiving a first hashed value from a mobile wireless communications device, said first hashed value having been generated from said identification information corresponding to said access device and a unique identifier corresponding to said mobile wireless communications device seeking to trigger unlocking of said access device; means for receiving, from said mobile wireless communications device, said unique identifier corresponding to said mobile wireless communications device; means for generating a second hashed value by hashing said unique identifier corresponding to said mobile wireless communications device with said identification information corresponding to said access device; means for determining if said first hashed value was generated from one of said mobile wireless communications devices authorized to control said access device based at least in part on determining that said second hashed value matches said first hashed value; and means for sending an access command for unlocking said access device after determining that said first hashed value was generated from one of said mobile wireless communications devices authorized to control said access device. ### Claim 6 (depends on 5) The access authorization device of claim 5, further comprising: means for denying access to said area after said means for determining determines that said first hashed value was not generated from one of said plurality of unique identifiers corresponding to mobile wireless communications devices authorized to control said access device and said identification information corresponding to said access device. ### Claim 7 (depends on 6) The access authorization device of claim 6, further comprising: means for generating an alert indicating an unauthorized access attempt after said means for determining determines that said first hashed value was not generated from one of said plurality of unique identifiers corresponding to mobile wireless communications devices authorized to control said access device and said identification information corresponding to said access device. ### Claim 8 (depends on 5) The access authorization device of claim 5, further comprising: means for generating said identification information corresponding to said access device by hashing an identifier corresponding to said access device with a time varying value. ### Claim 9 An access authorization device, comprising: a memory; and at least one processor configured to: store, in said memory, a plurality of unique identifiers corresponding to mobile wireless communications devices authorized to control an access device used to control access to an area; provide identification information corresponding to said access device to a light emitting device by way of a power line network; receive a first hashed value from a mobile wireless communications device, said first hashed value having been generated from said identification information corresponding to said access device and a unique identifier corresponding to said mobile wireless communications device seeking to trigger unlocking of said access device; receive, from said mobile wireless communications device, said unique identifier corresponding to said mobile wireless communications device; generate a second hashed value by hashing said unique identifier corresponding to said mobile wireless communications device with said identification information corresponding to said access device; determine if said first hashed value was generated from one of said mobile wireless communications devices authorized to control said access device based at least in part on determining that said second hashed value matches said first hashed value; and send an access command to unlock said access device after determining that said first hashed value was generated from one of said mobile wireless communications devices authorized to control said access device. ### Claim 10 (depends on 9) The access authorization device of claim 9, wherein said at least one processor is further configured to deny access to said area after determining that said first hashed value was not generated from one of said plurality of unique identifiers corresponding to mobile wireless communications devices authorized to control said access device and said identification information corresponding to said access device. ### Claim 11 (depends on 10) The access authorization device of claim 10, wherein said at least one processor is further configured to generate an alert indicating an unauthorized access attempt after determining that said first hashed value was not generated from one of said plurality of unique identifiers corresponding to mobile wireless communications devices authorized to control said access device and said identification information corresponding to said access device. ### Claim 12 A computer program product for use in an access authorization device, the computer program product comprising: a non-transitory computer readable medium comprising: code for causing at least one computer to store a plurality of unique identifiers corresponding to mobile wireless communications devices authorized to control an access device used to control access to an area; code for causing said at least one computer to provide identification information corresponding to said access device to a light emitting device by way of a power line network; code for causing said at least one computer to receive a first hashed value from a mobile wireless communications device, said first hashed value having been generated from said identification information corresponding to said access device and a unique identifier corresponding to said mobile wireless communications device seeking to trigger unlocking of said access device; code for causing said at least one computer to receive, from said mobile wireless communications device, said unique identifier corresponding to said mobile wireless communications device; code for causing said at least one computer to generate a second hashed value by hashing said unique identifier corresponding to said mobile wireless communications device with said identification information corresponding to said access device; code for causing said at least one computer to determine if said first hashed value was generated from one of said mobile wireless communications devices authorized to control said access device based at least in part on determining that said second hashed value matches said first hashed value; and code for causing said at least one computer to send an access command to unlock said access device after determining that said first hashed value was generated from one of said mobile wireless communications devices authorized to control said access device. ### Claim 13 (depends on 9) The access authorization device of claim 9, wherein said at least one processor is further configured to generate said identification information corresponding to said access device by hashing an identifier corresponding to said access device with a time varying value. ### Claim 14 (depends on 12) The computer program product of claim 12, wherein said non-transitory computer readable medium further comprises: code for causing said at least one computer to deny access to said area after determining that said first hashed value was not generated from one of said plurality of unique identifiers corresponding to mobile wireless communications devices authorized to control said access device and said identification information corresponding to said access device. ### Claim 15 (depends on 14) The computer program product of claim 14, wherein said non-transitory computer readable medium further comprises: code for causing said at least one computer to generate an alert indicating an unauthorized access attempt after determining that said first hashed value was not generated from one of said plurality of unique identifiers corresponding to mobile wireless communications devices authorized to control said access device and said identification information corresponding to said access device. ### Claim 16 (depends on 12) The computer program product of claim 12, wherein said non-transitory computer readable medium further comprises: code for causing said at least one computer to generate said identification information corresponding to said access device by hashing an identifier corresponding to said access device with a time varying value.