Ultra-wideband radar for tailgating detection in access control systems

Abstract

To provide a reader device of a physical access control system capable of providing seamless access.SOLUTION: A reader device of a physical access control system includes an ultra-wide band (UWB) physical layer; and processing circuitry. The processing circuitry is operatively coupled to the UWB physical layer and configured to: receive access credential information from a separate second device; receive ranging information from the second device; grant access through a physical portal according to the access credential information and ranging information; determine a number of people intending to pass through the physical portal; and generate an indication according to the determined number.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The embodiments illustrated and described herein generally relate to access control system architectures that include ultra-wideband enabled devices. [Background technology]

[0002] Ultra-wideband (UWB) is a radio frequency (RF) technique that uses short, low-power pulses across a wide frequency spectrum. The pulses are on the order of millions of individual pulses per second. The width of the frequency spectrum is typically greater than 500 megahertz, or greater than 20 percent of the arithmetic center frequency. [Brief explanation of the drawings]

[0003] [Figure 1] Figure 1 shows the structure of a basic physical access control system (PACS). [Figure 2] FIG. 2 is a block diagram of an example of an ultra-wideband (UWB) enabled device and a smart UWB enabled device that includes angle of arrival functionality. [Figure 3] FIG. 3 is a block diagram illustrating the use of a channel impulse response estimation function of a UWB-enabled reader device for UWB radar. [Figure 4] FIG. 4 is a flow diagram of a method for operating a seamless PACS. [Figure 5] FIG. 5 is a schematic block diagram of portions of an example UWB-enabled device. DETAILED DESCRIPTION OF THE INVENTION

[0004] Seamless access control refers to authorized users being granted physical access through a controlled portal without requiring intrusive user interaction, such as inserting or swiping an access card at a card reader or entering a personal identification number (PIN) or password. A physical access control system (PACS) is a type of system that can provide seamless access. PACS authenticate and authorize users to pass through physical access points, such as secured doors. PACS architectures can vary significantly depending on the application (e.g., hotel, residential, office), technology (e.g., access interface technology, door type), and manufacturer.

[0005] Figure 1 shows a basic PACS structure useful for office applications. An access credential is a data object, a piece of knowledge (e.g., a PIN, password), or a physical facet of a person (e.g., a face, fingerprint, etc.) that proves the person's identity. If the access credential is a data object, a credential device 104 stores the access credential. The credential device 104 may be a smartcard or a smartphone. Other examples of credential devices include, but are not limited to, proximity radio frequency identification (RFID)-based cards, access control cards, credit cards, debit cards, passports, identification cards, key fobs, near field communication (NFC)-enabled devices, mobile phones, personal digital assistants (PDAs), tags, or other devices that can be configured to emulate virtual credentials.

[0006] The credential device 104 may be referred to as an access credential. The reading device 102 obtains and authenticates the access credential when the credential device is used and transmits the access credential to the access controller 106. The access controller 106 compares the access credential with an access control list and, based on the comparison, grants or denies access, for example, by controlling the automatic locking of a door.

[0007] The functionality of the access controller 106 may be included in the reading device 102. These reading devices may be referred to as offline or standalone readers. If an unlocking mechanism is also included, the device is referred to as a smart door lock and is typically more used in residential applications. Devices such as smart door locks are often battery-powered, and power consumption and battery life may be important parameters for the device.

[0008] For physical access applications, electronic devices must authenticate individuals, which may require methods different from those used for mutually authenticating multiple electronic devices. Individual authentication methods typically fall into three broad categories: something you know, something you have, or something you are. For PACS, proof of presence is just as important as authentication for granting access through a specific physical portal at a given time. Impulse Radio Ultra-Wideband (IR-UWB, or simply UWB) can provide proof of presence information in a secure manner.

[0009] UWB is a wireless communication method that uses wide signal bandwidths. Wide bandwidth is typically defined as a bandwidth greater than 20% of the signal's center frequency at -10 decibels (-10 dB), or an absolute bandwidth greater than 500 megahertz (500 MHz). Commercial UWB systems are intended for use in complex environments such as homes, offices, or multiple indoor industrial areas. In these environments, signal reflection and diffraction play a significant role. The signal received at the antenna is the sum of attenuated, delayed, and sometimes superimposed versions of the transmitted signal, which may vary over time (due to receiver / transmitter movement or environmental changes). These different variations of the transmitted signal are typically referred to as multipath components. The wide bandwidth of UWB systems makes them highly resistant to frequency-selective fading, an effect that limits the performance of narrowband technologies.

[0010] In a PACS, an access sequence can have four parts: proof of presence, intent detection, authentication, and authorization. A user approaches a door and presents an access credential or credential device, which provides the proof of presence and intent portions of the sequence. The reading device checks the validity of the access credential (the authentication portion) and transmits it to an access controller (e.g., using a local area network or LAN), which then grants or denies access (the authorization portion). As explained above, seamless access is access that is granted without requiring intrusive actions to demonstrate intent (e.g., presenting a card, entering a password, etc.), while maintaining the same level of security as traditional access systems. UWB's secure and accurate ranging capabilities make it a suitable technique for enabling seamless access because ranging can be used to determine presence and intent without the need for user action.

[0011] 2 is a block diagram of an example of a UWB-enabled device 202 (e.g., a reader device or reader-controller device) and a smart UWB-enabled device 204 (e.g., a smartphone credential device). Ranging by the UWB-enabled device can be used to determine user intent. Intent can be inferred by changes in distance between the UWB-enabled device 202 and the smart or credential UWB-enabled device 204 and by changes in angle between the UWB-enabled device 202 and the smart UWB-enabled device 204.

[0012] UWB-enabled devices can perform ranging using Time-of-Flight (TOF) Two-Way Ranging (TWR). In TWR, multiple wireless packets are exchanged between a UWB-enabled device (e.g., a reader device) and a smart UWB-enabled device (e.g., a UWB-enabled smartphone). The timing difference between the transmission and reception of packets between the reader device and the smartphone can be used to calculate ranging information, such as changes in distance and / or angle, to determine intent.

[0013] There can be security issues with seamless access control. For example, a seamless access system that opens a door when an authorized user is within two meters may allow entry to more than just the authenticated user if another person approaches behind or "tailgates" the authenticated user. The radio frequency signal transmission capabilities of UWB-enabled devices can be used to improve the security of seamless access systems.

[0014] In a seamless access system, a UWB-enabled reading device can switch from two-way ranging operations to one-way transmission of radio frequency (RF) signal pulses and detection of received RF pulses that are reflected from an object. The transmission of pulses and reception of reflected pulses can be used by the UWB-enabled reading device to detect tailgating.

[0015] In some examples, the RF pulses may be a particular string or pattern of UWB pulses. The UWB-enabled reading device may include a correlator that determines a channel impulse response (CIR) from the pattern of transmitted pulses. The correlator may be included in processing circuitry of the UWB-enabled reading device. The correlator may determine the CIR by acting as a deconvolution operator on a known pulse pattern. In some examples, the particular pulse pattern transmitted has low autocorrelation properties. In some examples, a preamble symbol included in a ranging packet may be the pulse pattern transmitted to the detecting radar.

[0016] FIG. 3 is a block diagram illustrating the use of a UWB-enabled reading device for UWB radar. A UWB-enabled reading device 302 transmits radar pulses. The signals transmitted by the UWB-enabled reading device are reflected by objects and people in the UWB-enabled reading device's environment. By determining the CIR of the reflected signals, the UWB-enabled reading device can obtain information about the RF characteristics of its environment. By periodically estimating the CIR based on the reflected signals, the UWB-enabled reading device can identify changes in the RF characteristics of its surroundings, such as changes caused by moving people. Thus, the UWB-enabled reading device's estimation of the CIR based on the reflected signals provides basic radar functionality. This can be used by the UWB-enabled reading device, following ranging / intent detection operations, to detect when a user has been granted access and when more people than the user attempt to physically pass through a physical entrance. For example, additional reflected signals may be received as the transmitted signals reflect off additional people. The additional reflections may be detected by the UWB-enabled reading device's processing circuitry as a change in the CIR of the received reflected signals.

[0017] 4 is a flow diagram of a method 400 of operating a seamless PACS. At 405, access credential information is transferred from a user's credential UWB-enabled device to a UWB-enabled reading device. The credential UWB-enabled device may be a smart UWB-enabled device (e.g., a smartphone or smart card) that stores the access credential information. The reading device may be an authentication-only device that compares the credential information with credentials for which access is permitted, or the reading device may be a combination authentication and control device that evaluates the credential information and provides access through a physical entry point (e.g., a door) if the credential information meets the criteria for access.

[0018] To exchange information, the credential UWB-enabled device may request to open a communication channel with the reading device to transfer the credential information. The communication channel may be a UWB communication channel or an out-of-band (OOB) channel. An example of an OOB channel is a Bluetooth® communication channel or a Bluetooth Low Energy (BLE) communication channel. Using BLE for the discovery and authentication phases provides low energy consumption overhead during the device discovery phase between the credential device and the reading device.

[0019] At 410, ranging information is transferred from the credential UWB-enabled device to the UWB-enabled reading device. The credential device and reading device perform two-way ranging (TWR), and the ranging information may include the credential device and reading device exchanging packetized information. The ranging information is exchanged using a UWB communication channel. In some examples, if the reading device determines that the credential information grants access, the UWB-enabled reading device and the credential UWB-enabled device may switch from communicating using an OOB communication channel to communicating using a UWB communication channel to transfer the ranging information.

[0020] At 415, in response to authenticating the credential information and using ranging to determine that the user is present and intends to pass through the physical entrance, the reading device allows the user to pass through the entrance. The UWB-enabled reading device may provide an indication of authorization (e.g., a signal or code) to an access controller device that provides physical access. If the reading device is a combined reading and control device, the reading and control device grants physical access to the entrance (e.g., by automatically opening or unlocking a door).

[0021] At 420, the UWB-enabled reading device determines the number of people who intend to pass through the entrance during the period for which physical access is permitted. In some examples, the reading device may periodically transmit a signal and use the reflected RF signal to determine the number of people. A correlator in the UWB-enabled reading device may determine the CIR of the incoming reflected signal by performing a deconvolution operation on the known pulse pattern of the incoming reflected signal.

[0022] At 425, after determining the number of persons intending to pass through the physical entrance, the UWB-enabled reading device generates an indication according to the determined number of persons. The indication may be an alert or alarm generated when more than one person (i.e., persons other than just the user of the credential device) gains or attempts to gain access through the physical entrance. The alarm may include one or both of a visual and an audible indication of the alarm condition. In some examples, the indication is a signal or code provided to the access control device. In a variation, the indication provided to the access control device is the determined number of persons. The access control device initiates an alarm or denies access based on the indication from the reading device.

[0023] 5 is a schematic block diagram of various example components of a UWB-enabled device 500 (e.g., an embedded device) for supporting the device architecture described and illustrated herein. Device 500 of FIG. 5 may be, for example, a UWB-enabled reader device that authenticates credential information of the authority, status, rights, and / or entitlement to privileges of the owner of the credential UWB-enabled device. At a basic level, a UWB-enabled device may include an interface (e.g., one or more antennas and an integrated circuit (IC) chip) that allows the device to exchange data with another device, such as a credential device or a reader device. One example of a credential device is an RFID smart card that stores data that allows the owner of the credential device to access a secure area or asset protected by the reader device.

[0024] With particular reference to FIG. 5 , additional examples of UWB-enabled devices 500 for supporting the device architectures described and illustrated herein may generally include one or more of a memory 502, a processor 504, one or more antennas 506, a communications port or communications module 508, a network interface device 510, a user interface 512, and a power source 514 or power circuitry.

[0025] The memory 502 is used in connection with the execution of application programming or instructions by the processing circuit, and the memory 502 can be used for temporary or long-term storage of program instructions or instruction sets 516 and / or authorization data 518, such as credential data, credential authorization data, or access control data or instructions, as well as any data, data structures, and / or computer-executable instructions necessary or desired to support the above-described device architecture. For example, the memory 502 can include executable instructions 516 used by the processor 504 of the processing circuit to operate other components of the device 500, to make access decisions based on the credential or authorization data 518, and / or to perform any functions or operations described herein, such as, for example, the method of FIG. 4. The memory 502 can include a computer-readable medium, which can be any medium that can contain, store, communicate, or transfer data, program code, or instructions used by or in connection with the device 500. A computer-readable medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device. More specific examples of suitable computer-readable media include, but are not limited to, an electrical connection having one or more wires, or a tangible storage medium such as a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a dynamic RAM (DRAM), any solid-state storage device, a common compact disc read-only memory (CD-ROM), or other optical or magnetic storage device. Computer-readable media should not be confused with, but includes, computer-readable storage media, which is intended to cover all physical, non-transitory, or similar embodiments of computer-readable media.

[0026] Processor 504 may correspond to one or more computer processing devices or resources. For example, processor 504 may be provided as silicon, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), any other type of integrated circuit (IC) chip, a collection of IC chips, etc. As a more specific example, processor 504 may be provided as a microprocessor, a central processing unit (CPU), or multiple microprocessors or CPUs configured to execute a set of instructions stored in internal memory 520 and / or memory 502.

[0027] The antenna 506 may correspond to one or more antennas and may be configured to provide wireless communication between the device 500 and another device. The one or more antennas 506 may be coupled to one or more physical (PHY) layers 524 to operate using one or more wireless communication protocols and operating frequencies, including, but not limited to, IEEE 802.15.1, Bluetooth, Bluetooth Low Energy (BLE), Near Field Communication (NFC), ZigBee, GSM, CDMA, Wi-Fi, RF, UWB, etc. In one example, the antenna 506 may include one or more antennas coupled to the one or more physical layers 524 to operate using UWB for in-band operation / communication and Bluetooth (e.g., BLE) for out-of-band (OOB) operation / communication. However, any RFID or personal area network (PAN) technology, such as IEEE 502.15.1, near field communications (NFC), ZigBee, GSM, CDMA, Wi-Fi, etc., may alternatively or additionally be used for the OOB operations / communications described herein.

[0028] The device 500 may further include a communications module 508 and / or a network interface device 510. The communications module 508 can be configured to communicate with one or more different systems or devices remote or local to the device 500 according to any suitable communications protocol. The network interface device 510 includes hardware that enables communication with other devices over a communications network utilizing any one of several transport protocols (e.g., Frame Relay, Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Hypertext Transfer Protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), a mobile phone network (e.g., a cellular network), a Plain Old Telephone (POTS) network, a wireless data network (e.g., the IEEE 802.11 family of standards called Wi-Fi®, the IEEE 802.16 family of standards called WiMax®), the IEEE 802.15.4 family of standards, a peer-to-peer (P2P) network, etc. In some examples, the network interface device 510 may include an Ethernet port or other physical jack, a Wi-Fi card, a network interface card (NIC), a cellular interface (e.g., an antenna, filters, and associated circuitry), etc.In some examples, the network interface device 510 may include multiple antennas to communicate wirelessly using at least one of Single-Input Multiple-Output (SIMO), Multiple-Input Multiple-Output (MIMO), or Multiple-Input Single-Output (MISO) techniques. In some demonstrative embodiments, the antenna 506, the communication module 508, and / or one or more of the network interface device 510, or subcomponents thereof, may be integrated as a single module or device, function or operate as if they were a single module or device, or may be comprised of multiple elements shared amongst themselves.

[0029] The user interface 512 may include one or more input devices and / or display devices. Examples of suitable user input devices that may be included in the user interface 512 include, but are not limited to, one or more buttons, a keyboard, a mouse, a touch-sensitive surface, a stylus, a camera, a microphone, etc. Examples of suitable user output devices that may be included in the user interface 512 include, but are not limited to, one or more LEDs, an LED panel, a display screen, a touch screen, one or more lights, a speaker, etc. It should be understood that the user interface 512 may also include combined user input and user output devices, such as a touch-sensitive display. The user interface 512 may include a separate alarm circuit 526 that indicates an alarm condition. The alarm circuit 526 may provide an audio signal to a speaker, activate a light, or indicate the alarm condition using a display device.

[0030] The power source 514 may be any suitable internal power source, such as a battery, a capacitive power source, or a similar type of charge storage device, and / or may include one or more power conversion circuits suitable for converting external power into suitable power for the components of the device 500 (e.g., converting externally supplied AC power to DC power).

[0031] The device 500 may also include one or more interlinks or buses 522 operable to transmit communications between the hardware components of the device. The system bus 522 may be any of several types of commercially available bus structures or architectures.

[0032] Additional Disclosure and Examples Example 1 includes subject matter (such as a seamless physical access control system (PACS) reading device) comprising an ultra-wide band (UWB) physical layer and processing circuitry operably coupled to the UWB physical layer, where the processing circuitry is configured to receive access credential information from a separate second device, receive ranging information from the second device, grant access through a physical entrance responsive to the access credential information and the ranging information, determine a number of persons intended to pass through the physical entrance, and generate an indication responsive to the determined number.

[0033] In Example 2, the subject matter of Example 1 optionally includes an alarm circuit, wherein the processing circuit is configured to activate the alarm circuit in response to a determined number of persons intending to pass through the physical entrance.

[0034] In Example 3, the subject matter of one or both of Examples 1 and 2 optionally includes a network interface, and wherein the processing circuitry is configured to provide the generated indication of the determined number of people to an access device of the seamless PACS via the network interface.

[0035] In Example 4, the subject matter of one or any combination of Examples 1-3 optionally includes an out of band (OOB) physical layer, wherein the processing circuitry is configured to: establish an OOB communication layer to receive access credential information; initiate transmission of a transmission signal using an UWB physical layer; receive, using the UWB physical layer, a reflected signal corresponding to the transmission signal reflecting off an object; and determine, using the received reflected signal, a number of persons intending to pass through the physical entrance.

[0036] In Example 5, the subject matter of Example 4 optionally includes a processing circuit configured to include a specified pattern of radio frequency (RF) signal pulses in the transmitted signal, estimate a channel impulse response (CIR) of the reflected signal using the specified pattern of RF signal pulses in the reflected signal, and determine the number of people using the estimated CIR of the reflected signal.

[0037] In Example 6, the subject matter of Example 5 optionally includes a processing circuit configured to include a preamble pattern in a preamble field in the transmitted signal and determine a CIR of the reflected signal using the preamble pattern in the reflected signal.

[0038] In Example 7, the subject matter of one or any combination of Examples 4-6 optionally includes processing circuitry configured to initiate transmission of a signal to determine the number of people after granting access to the user.

[0039] In Example 8, the subject matter of one or any combination of Examples 4-6 optionally includes a processing circuit configured to initiate transmission of a signal to determine the number of people after receiving a request to open a communication channel from the second device.

[0040] In Example 9, the subject matter of one or any combination of Examples 4-6 optionally includes a processing circuit configured to initiate transmission of a signal to determine the number of people after exchanging ranging information with the second device.

[0041] Example 10 may include or be optionally combined with one or any combination of Examples 1-9 to include subject matter (such as a method for operating a seamless physical access control system), and may comprise transferring access credential information from a user's ultra-wide band (UWB) enabled device to a UWB enabled reading device; transferring ranging information from the credential UWB enabled device to the UWB enabled reading device; granting access through a physical entrance responsive to the access credential information and the ranging information; determining, with the UWB enabled reading device, a number of persons intending to pass through the physical entrance; and generating, with the UWB enabled reading device, an indication responsive to the determined number.

[0042] In Example 11, the subject matter of Example 10 optionally includes transmitting a radio frequency (RF) signal using a UWB-enabled reading device, receiving a reflected RF signal corresponding to the transmitted RF signal reflected from an object, and using the reflected signal to determine a number of people intending to pass through a physical entrance.

[0043] In Example 12, the subject matter of Example 11 optionally includes transmitting an RF signal including a specified pattern of RF signal pulses, estimating a channel impulse response (CIR) of a reflected signal using the specified pattern of RF pulses, and determining the number of people as a function of changes in the estimated CIR of the reflected signal.

[0044] In Example 13, the subject matter of Example 12 optionally includes transmitting an RF signal including a preamble field of the transmitted wireless packet as a specified pattern of RF signal pulses.

[0045] In Example 14, the subject matter of one or any combination of Examples 11-13 optionally includes transmitting a specified pattern of UWB signal pulses. In Example 15, the subject matter of one or any combination of Examples 10-14 optionally includes the UWB-enabled reading device determining the number of people after granting access to the users.

[0046] In Example 16, the subject matter of one or any combination of Examples 10-14 optionally includes determining the number of people after the UWB-enabled reading device receives a request from the credential device to open a communication session.

[0047] In Example 17, the subject matter of one or any combination of Examples 10-16 optionally includes generating an alert when the determined number is two or more. In Example 18, the subject matter of one or any combination of Examples 10-17 optionally includes transmitting the determined number of persons to an access control device.

[0048] In Example 19, the subject matter of one or any combination of Examples 10-18 optionally includes transferring access credential information using an out of band (OOB) communication channel established between the UWB-enabled reading device and the credential UWB-enabled device, transferring ranging information using the UWB communication channel, and determining the number of persons intending to pass through the physical entrance.

[0049] Example 20 includes subject matter such as a non-transitory computer-readable storage medium (or may be optionally combined with one or any combination of Examples 1-19 so as to include such subject matter) including a plurality of instructions that, when executed by processing circuitry of an ultra-wide band (UWB) enabled device, cause the UWB enabled device to perform a plurality of operations, the plurality of operations including receiving access credential information from a distinct second device, receiving ranging information from the second device, granting access through a physical entrance responsive to the access credential information and the ranging information, determining a number of persons intending to pass through the physical entrance, and generating instructions responsive to the determined number.

[0050] In Example 21, the subject matter of Example 20 optionally includes instructions that cause the UWB-enabled device to perform operations including transmitting a signal using a physical layer of the UWB-enabled device, receiving a reflected signal corresponding to the transmitted signal reflected from an object, and determining a channel impulse response (CIR) of the reflected signal.

[0051] In Example 22, the subject matter of Example 21 optionally includes instructions for causing a UWB-enabled device to perform operations including transmitting a signal including a specified pattern of UWB signal pulses and estimating a CIR of the reflected signal using deconvolution on a received reflected signal in accordance with the specified pattern of UWB signal pulses.

[0052] The above-described examples may be combined in any permutation or combination. The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, for purposes of illustration, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as "examples." All publications, patents, and patent documents mentioned herein are incorporated by reference in their entirety, as if individually incorporated by reference. In the event of a conflicting usage between this specification and those documents incorporated herein by reference, the usage of the incorporated reference(s) shall be deemed to supplement the usage of this specification, with the usage of this specification taking precedence in the event of any irreconcilable discrepancy.

[0053] The terms "a" or "an" are used herein, as is common in patent documents, to include one or more, independently of any other instance or use of "at least one" or "one or more." The term "or" is used herein to mean non-exclusive, unless otherwise noted, or such that "A or B" includes "A but not B," "B but not A," and "A and B." The terms "including" and "in which" are used herein as the plain-English equivalents of the respective terms "comprising" and "wherein." Also, in the appended claims, the terms "comprising" and "comprising" are open-ended, i.e., systems, devices, articles, compositions, formulations, or processes that include elements in addition to those listed after these terms in a claim are still considered to be within the scope of that claim. Furthermore, in the appended claims, the terms "first," "second," and "third," etc., are used merely as labels and are not intended to impose numerical requirements on their objects.

[0054] The foregoing description should be construed as illustrative, not limiting. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. For example, other embodiments may be employed by those skilled in the art upon reference to the above description. The Abstract is provided to enable the reader to quickly identify the nature of the technical disclosure. It should be understood that it is not used to interpret or limit the scope or meaning of the claims. In the foregoing Detailed Description, various features may be grouped together to streamline the disclosure. This should not be construed as intending that any unclaimed disclosed feature is essential to any claim. Rather, the present subject matter may reside in some features of particular disclosed embodiments. Thus, the appended claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope should be determined with reference to the appended claims, along with the full range of equivalents to which the claims are entitled.

Claims

1. A reading device for an access control system, comprising: an ultra-wideband (UWB) physical layer; a processing circuit operably coupled to the UWB physical layer; The processing circuitry receiving access credential information from a second device; using two-way ranging to receive ranging information from the second device using the UWB physical layer; authorizing access to a resource by a user of the second device according to the access credential information and the ranging information; using unidirectional signaling to transmit UWB signals using the UWB physical layer after granting access to the resource by the user of the second device; receiving, using the UWB physical layer, a reflected signal corresponding to the transmitted UWB signal that reflects off one or more objects; detecting one or more persons using the received reflected signals; generating instructions according to the number of people detected; The reading device, wherein generating the indication includes generating an alarm when the number of detected people is two or more.

2. 2. The reading device of claim 1, wherein the processing circuitry includes a correlator configured to determine a channel impulse response (CIR) of the reflected signal and to use the CIR of the reflected signal to detect the one or more persons in an environment of the reading device.

3. 3. The reading device of claim 2, wherein the processing circuitry is configured to transmit a specific pulse pattern of radio frequency (RF) pulses in the one-way signal transmission, and the correlator is configured to perform deconvolution of the specific pulse pattern to determine the reflected signal.

4. 3. The reading device of claim 2, wherein the processing circuitry is configured to transmit a specific plurality of preamble symbols in the one-way signal transmission, and the correlator is configured to perform deconvolution of the specific plurality of preamble symbols to determine the reflected signal.

5. The processing circuitry detecting a change in the number of received reflected signals corresponding to the transmitted UWB signal reflecting off one or more objects; 2. The reading device of claim 1, configured to: generate an alarm in response to the change in the number of received reflected signals.

6. The processing circuitry opening a UWB communication channel with the second device in response to a request from the second device; receiving the access credential information from the second device using the UWB communication channel; 2. The reading device of claim 1, configured to: perform the two-way ranging using the UWB communication channel.

7. an out-of-band (OOB) physical layer; 2. The reading device of claim 1, wherein the processing circuit is operably coupled to the OOB physical layer and configured to establish an OOB communication channel with the second device and receive the access credential information from the second device using the OOB communication channel.

8. The processing circuitry If the access credential information is authenticated, opening an UWB communication channel with the second device and switching to communication with the second device using the UWB communication channel; and receiving the two-way ranging information from the second device using the UWB communication channel.

9. The processing circuitry authenticating the access credentials; and initiating the two-way ranging in response to authenticating the access credential information; The reading device of claim 1 , configured to: selectively grant access to the resource depending on the number of people detected.

10. a network interface operably coupled to the processing circuit; The reading device of claim 1 , wherein the processing circuitry is configured to provide the instruction generated in response to the number of detected people to a third device via the network interface.

11. 1. A method of operating a reading device to control access to a resource, comprising: receiving access credential information from a second device; using two-way ranging over an ultra-wideband (UWB) communication channel established by the reading device to receive ranging information from the second device; authorizing access to the resource by a user of the second device according to the access credential information and the ranging information; performing a one-way UWB signal transmission by the reading device after allowing the user of the second device to access the resource; receiving, by the reading device, reflected UWB signals corresponding to the transmitted UWB signals reflected from one or more objects; detecting one or more persons using the received reflected UWB signals; generating an alarm signal in response to the number of people detected; The method, wherein generating the alarm signal includes generating the alarm signal when the number of detected people is two or more.

12. 12. The method of claim 11, comprising the reading device determining a channel impulse response (CIR) of the reflected UWB signal and using the CIR to identify the reflected UWB signal.

13. 13. The method of claim 12, comprising the reading device transmitting a specific pulse pattern of radio frequency (RF) pulses in the one-way UWB signal transmission and performing deconvolution of the specific pulse pattern to determine the reflected UWB signal.

14. 13. The method of claim 12, comprising: the reading device transmitting a plurality of specific preamble symbols in the one-way UWB signal transmission; and performing deconvolution of the plurality of specific preamble symbols to determine the reflected UWB signal.

15. the reading device detecting a change in the number of received reflected signals corresponding to the transmitted UWB signal reflecting off one or more objects; and generating an alarm in response to the change in the number of received reflected signals.

16. the reading device establishing the UWB communication channel in response to a request received from the second device; and receiving the access credential information from the second device using the UWB communication channel.

17. In response to a request from the second device, the reading device establishes an out-of-band (OOB) communication channel between the reading device and the second device; and receiving the access credential information from the second device using the OOB communication channel.

18. 18. The method of claim 17, further comprising: if the access credential information received via the OOB communication channel is authenticated, the reading device opening the UWB communication channel with the second device and switching to communication with the second device using the UWB communication channel.

19. the reading device authenticating the access credential information; initiating the two-way ranging in response to authenticating the access credential information; and selectively granting access to the resource depending on the number of people detected by the reading device.

20. 20. A computer readable storage medium comprising a plurality of instructions which, when executed by processing circuitry of a reading device of an access control system, cause the reading device to perform the method of any one of claims 11 to 19.

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