Patent Publication Number: US-2020285840-A1

Title: Methods and systems for an access control system using visual recognition

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Patent Provisional Application No. 62/809,416, filed Feb. 22, 2019, the entire contents of which is hereby incorporated in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure generally relates to an access control system implementing visual recognition, and in some cases in conjunction with visual and audible feedback, for governing access to a specific location. 
     BACKGROUND 
     An access control system is often used at public and private premises, such as households, commercial buildings, businesses, retail establishments, schools, hospitals and government buildings, to list a few examples. Access control system nodes may be installed at access points of the premises (e.g. front and interior doors of a building) to control access to restricted areas, such as the building itself or to areas within the buildings. The access control system authenticates (or authorizes) an access card or pass held by an individual and then permits individuals with authenticated access cards to access the restricted areas through the access point. 
     Historically, the main components of the access control system are access card readers and possibly door controllers. The access card readers are often installed at the access points and enabled presentation of credentials to obtain access to the restricted areas. Typically, individuals interact with the access card readers by presenting access cards, such as keycards or contactless smart cards, to the readers. The access card readers read the credential information of the access card, and compare the information against a database of authorized individuals to determine if the individual presenting the access card is authorized to access the restricted areas. If the individual is authorized, then the access card reader might signal the door controller, for example, to unlock doors or not generate alarms. 
     In view of the foregoing, there is a need to more efficiently and more securely, and in more user friendly manner, control access to restricted areas. 
     SUMMARY 
     The following presents a simplified summary of one or more implementations of the present disclosure in order to provide a basic understanding of such implementations. This summary is not an extensive overview of all contemplated implementations, and is intended to neither identify key or critical elements of all implementations nor delineate the scope of any or all implementations. Its sole purpose is to present some concepts of one or more implementations of the present disclosure in a simplified form as a prelude to the more detailed description that is presented later. 
     The present disclosure relates to an access control system that implements visual recognition to identify and authenticate an individual in to control access to a restricted area. In some cases, the access control system may further operate in conjunction with visual and audible feedback. 
     One example implementation relates to a system for an access control device using visual recognition and visual and/or audible feedback. One aspect of the system comprises a camera configured to obtain an image. Another aspect of the system comprises a plurality of light emitting diodes (“LEDs”) arranged in a plurality of segments relative to the camera, where the plurality segments are individually controllable to provide a status indication to an individual attempting to enter the restricted area. In another aspect of the system, the LEDs are configured to illuminate upon a received control signal based upon one or more access control trigger events. 
     Additional advantages and novel features relating to implementations of the present disclosure will be set forth in part in the description that follows, and in part will become more apparent to those skilled in the art upon examination of the following or upon learning by practice thereof. 
    
    
     
       DESCRIPTION OF THE FIGURES 
       The novel features believed to be characteristic of the disclosure are set forth in the appended claims. In the descriptions that follow, like parts are marked throughout the specification and drawings with the same numerals, respectively. The drawing figures are not necessarily drawn to scale and certain figures may be shown in exaggerated or generalized form in the interest of clarity and conciseness. The disclosure itself, however, as well as a preferred mode of use, further objects and advances thereof, will be best understood by reference to the following detailed description of illustrative aspects of the disclosure when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1A  illustrates a schematic view of an example operating environment of an access control system implementing visual recognition, including an example front view a user attempting to access a location via a door, and also including an inset example side view of an alternative operating environment similarly including a user attempting to access a location via a door, in accordance with aspects of the present disclosure; 
         FIG. 1B  is a schematic view of another example operating environment of an access control system implementing visual recognition similar to  FIG. 1A  but further including a person tracking unit in accordance with aspects of the present disclosure; 
         FIG. 2  is a flowchart of an example method of operation, and interactions between various modules of, the access control system implementing visual recognition, in accordance with aspects of the present disclosure; 
         FIG. 3  is a front view of an example visual and audible feedback access control device in accordance with aspects of the present disclosure; 
         FIG. 4  is a front view of an example set of illumination sequences of a visual feedback access control device in accordance with aspects of the present disclosure; 
         FIG. 5  is a message and data flow diagram of an example method of access control implementing visual recognition in accordance with aspects of the present disclosure; 
         FIG. 6  is a block diagram of various hardware components and other features of a computer system that may operate the access control system in accordance with aspects of the present disclosure; and 
         FIG. 7  is a block diagram of various example system components, for use in accordance with aspects of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure relates to systems, devices, and methods for managing and controlling access to specific locations by specific users, such as authorized and/or unauthorized users attempting to access secure locations, by determining the identities of users based upon their visual appearance. The present disclosure describes a system having a separate remote sensor device, such as a camera, for obtaining an image of a user and providing visual and/or audible feedback as to state of the access control process (e.g., image acquisition, identity determination, authentication, and/or access determination), and a separate management system for determining both the identity of the user and the access permission level of the identified user. 
     Referring to  FIG. 1A , in an example implementation, an operating environment  100  includes an access control system  102  for managing and controlling access to one or more specific locations  105  by one or more specific users  101 , by determining the identities of users based upon their visual appearance. The access control system  102  may comprise a sensor  106 , such as a camera, that obtains an image of a user  101 . In one aspect, the image generated by the sensor  106  may be a video comprising a plurality of image frames, or a single still frame. For example, in one example implementation, the sensor  106  may be located near a door or access point on a wall or ceiling, where a traditional card access reader would be located controlling access. In some implementations, the sensor  106  may comprise a plurality of cameras devices used in conjunction with each other. For example, the first camera device may capture an image of a user  101  comprising their face as they approach the location of the door or access point, while the second camera device may supplement the image obtained by the first camera with liveliness (e.g., the captured image is not a picture, such as based on movement) and/or depth detection information generated by or detectable using one or more additional image frames. 
     In response to obtaining an image or images, the sensor  106  may transmit the raw data of the image(s) to a control unit  108  via bus  122 . In an implementation, bus  126  may be a CAT6 shielded cable or any other suitable bus that provides both data transfer and power to the sensor  106 . 
     The control unit  108  receives the raw data from the sensor  106 , and forwards the raw data via bus  126  to a facial recognition server  110 . In another example implementation, the control unit  108  may support wired or wireless communication (e.g., Bluetooth™ and/or WiFi, which can allow for multifactor authentication, when implemented in conjunction with facial recognition. Further, bus  126  may also be connected a network switch  124  (e.g., a POE+switch), allowing broadband capability for remote access. 
     The facial recognition server (FRS)  110  may receive the raw live video and/or the still image(s) from one or more sensors  106  for processing to determine an identity of the user. The FRS  110  may also perform liveness detection of the users based on the raw live video stream to determine if the users identified are actually alive rather than a decoy, for example, a photograph or a mannequin of a user. Further, in another example implementation, the FRS  110  stores digital representations of facial data entered previously, not actual images of faces. Examples of digital representations of facial data may include, but are not limited to, bitmaps, hashed or other encoded versions of the image data, etc. The FRS  110  may be updated with new or additional digital representations of users via management server  112 . In one example implementation, the FRS  110  performs facial recognition on the raw stream obtained from the sensor  106 . The FRS  110  may be located in the same location as the sensor  106  and control unit  108 , for example, the same building or room, or may be located in a remote location, for example, the cloud or a remote building from the management server  112  and the sensor  106 . In one example of operation, the FRS  110  may compare the obtained facial recognition of the raw data stream to the digital representations of faces previously stored in a database to determine whether there is a match. In response to the comparison, the FRS  110  may generate a determination signal indicating if the user is known (e.g., a match with the previously entered facial data is found or determined within a threshold level of confidence) or unknown. In another example implementation, the FRS  10  may not generate a determination signal if the user is unknown in the database. In another example implementation, the generated determination signal may further comprise a confidence score. The FRS  110  may transmit the generated determination signal to the control unit  108  and/or the management server  112  via bus  126 . 
     The management server  112 , described in detail below, may also receive the determination signal via the bus  126 . The management server  112  may log/record the determination signal; for example, the comparison results may be logged/recorded, the confidence score may be logged/recorded, the time and/or date the comparison was performed may be logged/recorded, the decision by the FRS  110  may be logged and/or recorded, and/or the identity of the user may be logged/recorded. The management server  112  may be located in the same location as the sensor  106  and control unit  108 , for example, the same building or room, or may be located in a remote location, for example, the cloud or a remote building from the management server  112  and the sensor  106 . 
     Referring back to the control unit  108 , the FRS  110  may transmit the determination signal via bus  126  to the control unit  108 , which may operate to control access to the. The control unit  108  may transmit the determination signal to an access device  114  via bus  130 . In one example implementation, the control unit  108  may support Bluetooth and/or WiFi communications, which may allow other types of multifactor authentication. In one example implementation, the control unit  108  may transmit an indication signal back to the sensor  106  via bus  122 . The sensor  106  may pass indications to the user at the location of the sensor  106  via lights and/or sound. The visual or light-based indications will discussed in detail below. In one example implementation, control unit  108  may exchange messages with access device  114  via bus  130 , wherein such communication messages may be in a particular protocol, for example, Open Supervised Device Protocol (OSDP) and Wiegand. The access device  114  may store access control information. The access control information may include if a user is allowed access to a specific location. For example, the access device  114  may store information indicating that a known user, e.g., user A, is permitted to access a specific location. Further, the access control information may be stored as a lookup table comprising information on specific users and the specific locations for which they may be allowed access. 
     The management server  112  may supply the access data stored in the control device  114  via bus  128 . The access data may be updated on a specific schedule, for example, every day, or may be updated when new information is placed in the management server  112 . In another example implementation, the access data may be stored solely on the management server  112 , or shared between the management server  112  and the control device  114 . For example, the access device  114  may receive the determination signal via bus  130  that indicates that user A is recognized and identified, as described above. The access device may attempt to determine if user A has access to location B via the access data stored in the device, or request the data from the management server  112 . In one example implementation, the data may be stored on the access device  114  to ensure access to specific locations if the bus  128  is cut, disconnected or damaged. Upon determination to grant or deny access to an identified user, an output signal is transmitted via bus  132  and  130  indicating the access status of the identified user. 
     The control unit  108  may receive the output signal via bus  130  comprising the access status indicating if the identified user has been granted access or denied access to a specific location. In one example implementation, the control unit  108  may transmit the output signal back to the sensor  106  via bus  122 . The sensor  106  may output indications to the user at the location of the sensor  106  via lights and/or sound based on the output signal. The visual indications and audible indications will discussed in detail below. 
     The access control system may further include a controllable locking unit  116 , for example attached to a door hinge, frame, door knob, handle, lock, or another feature of a door or structure removably blocking access to the location  105 . The locking unit  116  may receive the output signal, via bus  132 , where the output signal includes an access status indicating if the identified user has been granted access or denied access to the location  105 . For example, the locking unit  116  may be an electronically controllable mechanical actuator that can be controlled to move between a locked position and an unlocked position. In one example implementation, if the user has been identified, as described above, and has been granted access to the location  105  via the control device  114 , the locking unit  116  unlocks the door  107  to enable the user  101  to access the location  105 . In an example, implementation, a door sensor  118  may be used to determine if the door  107  has been opened, closed, how long the door  107  has been opened and how long the door  107  has been closed, in order to make subsequent access-related decisions. For example, the locking unit  116  may not unlock the door again if the door has not yet been determined to be closed via door sensor  118 . Further, an emergency opening device  120  may be present on the reverse side of the door. The emergency opening device  120  may be triggered by a user  101  in an emergency to immediately unlock the door via the locking unit  116 . Further details regarding an example method of operation of the system illustrated in  FIG. 1A  will be described below with reference to  FIG. 2 . 
     In a further example implementation, operating environment  104  includes the same features described above, but further illustrates the comprehensive operating abilities of the sensor  106 , e.g., being able to detect and make access decisions for all types of users. 
     The structure and configuration of the sensor  106  is described in detail below with reference to  FIG. 3  and  FIG. 4 . 
     Referring to  FIG. 1B , in another example implementation, the operating environment  100  includes access control system  102  for managing and controlling access to specific locations by specific users, by determining the identities of users based upon their visual appearance according to an aspect of the disclosure. As described above with reference to  FIG. 1A , the same aspects are illustrated in  FIG. 1B . In one aspect of the invention, the FRS  110  further interacts with a person-tracking unit  111 . The person-tracking unit  111  may further comprise a person tracking system, a person re-identification system and a video recording system. These three systems may all be placed within the person-tracking unit  111 , or separated into discrete components interacting with the person-tracking unit  111 . Together, the FRS  110  and the person-tracking unit  111  may be referenced as the tracking system  113 . In one example implementation, rather than using facial recognition alone, as described above, a user may be further identified based on the images captured from sensor  106 , for example, the clothes that they are wearing, their physical proportions, and/or other non-biometric data particular to the user. Working in conjunction with the FRS  110  and the person-tracking unit  111 , the tracking system  113  may provide improved user validation for the access control system  102 . 
     As described above, the sensor  106  may supply a live raw video stream to the tracking system  113 . The live raw video stream may be generated by sensor  106  at a specific location, or all cameras  106  from various locations within a building/location. A video recording system (not shown) may record the video from all cameras  106  supplying live raw video streams. The FRS  110  may analyze the live raw video and provide an output containing the identified user or users in the live video. As described above, the output may also contain a confidence level. The person-tracking unit  111  will also analyze the live raw video stream provided by the sensor  106  by comparing the live raw video with stored historical video. The person-tracking unit  111  may provide an output containing the identified user or users in the live video. The output from the person-tracking unit  111  may also contain a confidence level of such determination. In one example implementation, the person-tracking unit  111  may also store the video, the location and/or time that a user is identified as the historical data. The outputs from the FRS  110  and the person-tracking unit  111  may be combined to produce a more accurate identification result, or allow a user to be positively identified with a higher confidence store than with facial recognition alone. In one example implementation, when facial information is not complete, for example, partially obscured or from a longer distance away, the tracking system  113  may still provide identification information with a confidence score based on a previous, higher confidence identification in combination with matching one or more characteristics associated with the previous identification, e.g., a particular size, shape, and/or color of an article of clothing. The method of the system illustrated in  FIG. 1B  will be described below with reference to  FIG. 5 . 
     Referring to  FIG. 2 , an example of a method  200  of the operation of and interactions between various modules of the access control system implementing visual recognition is explained in accordance with one implementation.  FIGS. 1A and 1B  may be referenced in combination with the flowchart of  FIG. 2 . To start, method  200  includes a user attempting to access a specific access control location, as described above. At step  202 , the sensor  106 , e.g., a camera, may generate the raw live video stream and transmit the raw video steam to the control unit  108 . The FRS  110  receives the raw video steam at step  204  and determines if facial data can be determined, as described above. If the user&#39;s face is not detected the method ends. If the user&#39;s face is detected, liveness is determined at step  206 . If the user does not exhibit liveness, the method ends. If the user is exhibits liveness the FRS  110  attempts to identify the user at step  208 . If the user is not identified by the FRS  110 , a signal is sent to the control unit  106  at step  210 . If the user is identified by the FRS  110 , a signal is sent to the control unit  106  at step  212   
     At step  214 , the control unit  108  determines if the user is identified by the FRS  110 . If the user is not identified, a signal is sent to the sensor  106  at step  216 . The sensor  106  receives the signal sent at step  216  and may be configured to provide a visual and/or audible alert to the user at the access location, as described below. If the user is identified, a signal is sent to the sensor  106  and the access device  114  at step  218 . The sensor  106  receives the signal sent at step  220  and may be configured to provide a visual and/or audible alert to the user at the access location, as described below. Further, the access device  114  receives the signal transmitted during step  218 . At step  222  the access device determines if the identified user is granted or denied access to a specific location. If the user is denied access, the locking unit  116  does not unlock the door. Further, (not shown) a signal may be sent to the sensor  106  at step  230  for signal interpretation at step  236 . The sensor  106  may receive the signal sent at step  230  and may be configured to provide a visual and/or audible alert to the user at the access location, as described below. If the user is granted access, the access device  114  determines if the user&#39;s credentials are expiring soon at step  224 . If the user&#39;s credentials are expiring soon, a signal is sent to the locking unit  116  at step  226 . If the user&#39;s credentials are not expiring soon, a signal is sent to the locking unit  116  at step  228 . At step  232  the locking unit  116  unlocks the door at the access point. Further, (not shown) a signal may be sent to the sensor  106  at step  232  for signal interpretation at step  236 . The sensor  106  may receive the signal sent at step  232  and may be configured to provide a visual and/or audible alert to the user at the access location, as described below. 
     At step  236 , the control unit  108  determines the illumination sequence of the sensor  106 , described below, based on at least a signal indicating user identification, access determination and face determination. At step  238 , the camera illuminates the LEDs in a specific illumination sequence based on the system determinations, described below. 
     Referring to  FIG. 3 , an example visual feedback access control device includes the sensor  106 , as referenced above, which may contain a plurality of segments of a light ring  306 . Each of the plurality of segments of the light ring  306  may comprise a plurality of light emitting diodes (LEDs). The LEDs, for example, may be a single LED device containing one red, green, and blue (RGB) LEDs. In one example implementation, sensor  106  of  FIG. 3  may comprise 8 segments, each of the 8 segments of the light ring  306  may each contain at least one LED. The illumination of the light ring  306  and the plurality of segments is described below with reference to  FIG. 4 . In one example implementation the sensor  106  may comprise a plurality of sensor devices  302 . As described above, the one or more sensor devices  302  may be a video camera, or a still camera that captures a plurality if images. In another example implementation, the sensor  106  may alternatively or additionally comprise a plurality of infrared (IR) illumination units  304 . The IR illumination units  304  may detect infrared energy (heat) and convert the detected heat into an electronic signal, which is then processed to produce a thermal image. In another example implementation, the IR units  304  may aid in night time illumination and also provide illumination in the day time to improve the facial data gathered for recognition. As illustrated in  FIG. 3 , for example, 16 separate IR illumination units are present, but this implementation is not limiting and it should be understood that any number of IR illumination units may be present. 
     In one example implementation the sensor  106  may also comprise a speaker and a microphone (not shown). The speaker and the microphone may be configured to work as an intercom systems. In an implementation, for example, the speaker and microphone may communication with other components of the system using a communication protocol, such as but not limited to the Session Initiation Protocol (SIP). In one example implementation, the speaker may be configured to generate alerts for a user attempting to access a specific location, for example, providing audible alerts that their image has been captured, the user has been identified, the user has been granted access to the specific location, the user has been denied access, the user has not been identified, and the like. For example, the audible alerts may be implemented with a synthesized voice or play an audio file to the user. Bus  122  in  FIGS. 1A and 1B , as described above, my provide a signal generate the alerts. In another example implementation, the microphone may provide audible communications to employees that manage operation of the system, for example, a two-way communication between the user  106  and an employee operating the system to discuss reasons for the user&#39;s denial of access to a specific location, requesting additional information from the user, or the like. In another example implementation the speaker and/or microphone of the sensor  106  may provide audible alerts and communication regarding an alarm or duress situation. 
     Referring to  FIG. 4 , an example set of access control device illumination sequences  400  include one or more illumination sequences that may be output by the sensor  106  to provide an indication too the user, e.g., of a status of their attempted access. The sensor  106 , as referenced above, may contain a plurality of segments of a light ring  306  as described above in reference to  FIG. 3 . As described above, the sensor  106  may receive signals via bus  122  referenced in  FIG. 1A  and  FIG. 1B . The signals may instruct the sensor  106  to illuminate the segments in different illumination sequences  400  based on one of a plurality of trigger events. For example, some trigger events may be: an image being successfully obtained by the sensor  106 ; the device being in a start-up state; the image being a match with one of a plurality of known images in a database when compared by the FRS  110 ; the image not being the match with any of the plurality of known images in the database of the FRS  110 ; the image being the match with the one of the plurality of known images in the database of the FRS  110  but not having an access permission to a specific location based on the management server  112 ; the image being the match with the one of the plurality of known images in the database of the FRS  110  and having the access permission to the specific location based on the management server  112 ; or an alarm/duress event. The illumination sequences  400  generated by the LEDs, for example, may be rotating green and blue colors; solid colors such as all yellow, all blue, all green all red; only the top half with solid colors; only the bottom half with solid colors; or flashing colors. Any color may be associated with any illumination sequence and with any trigger event. For example, each trigger event may have a respective pre-programmed illumination sequence, or each trigger event may be user selected. 
     Referring to  FIG. 5 , an example message and data flow  500  of a method of access control performed by an access control system implementing visual recognition may reference the aspects described above with reference to  FIG. 1B . In one example, a user approaches an access point, and the user will be visible in the video stream from the sensor  106  associated with a specific access point. At step  502  the sensor  106  generates and transmits the raw video stream to the FRS  110 . At step  504 , the FRS  110  identifies a user and transmits the identification information of the user to the to the person tracking unit  111 . For example, the FRS  110  will attempt to identify a user approaching the access point by using the live raw video feed from the sensor  106 . The tracking system  113  will also record the time and position information for the identified user approaching the access point. Once the user is identified, the management server  112  will be notified, as described above. At step  506 , the person tracking unit  111  requests the video information from the video recording system. At step  508 , the video recording system supplies the video information to the person tracking unit  111 . At step  510 , the person tracking unit  111  receives a list of previous accesses of the access location by the user from the management server  112 . For example, the management server  112  queries its database and assembles a list of accesses for all access points that the identified user has had over a specified period. At step  512 , the person tracking unit  111  requests and receives video clips from the video recording system showing the user accessing the location. At step  514 , the tracking system attempts to find tracking information of the identified user in each of the supplied video clips. At step  516 , the identified video clip information, the previous identified video clip information and tracking information are sent to the person re-identification system. At steps  518  and  520 , the person re-identification system will request and receive requested video clips and at step  524 , the person re-identification system provides an assessment of how alike the current image of the identified user is verse the previous images of the identified user. At step  526 , the tracking system  113  combines the output from the FRS  110  and the output from the person tracking unit  111  to determine whether the user is accurately identified. 
     In one example implementation, the determination of if a user is identified may be based upon a comparison to a threshold. For example, by combining the FRS  110  output, indicating user A with a confidence score of 98%, and the person tracking unit  111  output, indicating user A with a confidence score of 80%, then a user is considered to be identified. In another example, by combining the FRS  110  output, indicating user A with a confidence score of 70%, and the person tracking unit  111  output, indicating user A with a confidence score of 90%, then a user is considered to be identified. 
     In one example implementation, some algorithms implemented by the tracking unit  111  to re-identify the user may have a high dependency on what a user is wearing, and this may change from day-to-day. To mitigate against this, the selection criteria for the video clips used for person re-identification system may be changed to include, for example, only clips for the current day or only video clips since the person entered the building. Implementing these types of criteria would enforce a rule that initial access to the location or building would require a positive identification of a person by facial recognition only, but access within the building would allow use of both the FRS  110  and the tracking unit  111 . 
     In another example implementation, the combination of the output from the FRS  110  and the output from the person tracking unit  111  may take into consideration a change of clothes during the same day (e.g., removed a big coat) by a user. For example, when both outputs have high confidence, the person will be granted access very quickly and from a further distance to the access point. When the person tracking unit  111  output confidence score is low the system will wait until it gets a high FRS  110  confidence score since the person may have changed their clothes. The tracking unit  111  may store all the different attributes of the same user when entering different access points, and the confidence of a new access will be based on a previous access where the attributes most resemble the current one, for example, when the user wore the same clothes. 
     Aspects of the present disclosure may be implemented using hardware, software, or a combination thereof and may be implemented in one or more computer systems or other processing systems. In one aspect, the disclosure is directed toward one or more computer systems capable of carrying out the functionality described herein.  FIG. 6  presents an example system diagram of various hardware components and other features that may be used in accordance with aspects of the present disclosure. Aspects of the present disclosure may be implemented using hardware, software, or a combination thereof and may be implemented in one or more computer systems or other processing systems. In one example variation, aspects of the disclosure are directed toward one or more computer systems capable of carrying out the functionality described herein. An example of such a computer system  600  is shown in  FIG. 6 . 
     Computer system  600  includes one or more processors, such as processor  604 . The processor  604  is connected to a communication infrastructure  606  (e.g., a communications bus, cross-over bar, or network). Various software aspects are described in terms of this example computer system. After reading this description, it will become apparent to a person skilled in the relevant art(s) how to implement aspects of the disclosure using other computer systems and/or architectures. 
     Processor  604 , or any other “processor,” as used herein, processes signals and performs general computing and arithmetic functions. Signals processed by the processor may include digital signals, data signals, computer instructions, processor instructions, messages, a bit, a bit stream, or other computing that may be received, transmitted and/or detected. 
     Communication infrastructure  606 , such as a bus (or any other use of “bus” herein, such as bus  122 ,  126 ,  128 ,  130 , and/or  132  as discussed above), refers to an interconnected architecture that is operably connected to transfer data between computer components within a singular or multiple systems. The bus may be a memory bus, a memory controller, a peripheral bus, an external bus, a crossbar switch, and/or a local bus, among others. The bus may also be a bus that interconnects components inside a access control system using protocols, such as Controller Area network (CAN), Local Interconnect Network (LIN), Wiegand and Open Supervised Device Protocol (OSDP) among others. 
     Further, the connection between components of computer system  600 , or any other type of connection between computer-related components described herein may be referred to an operable connection, and may include a connection by which entities are operably connected, such that signals, physical communications, and/or logical communications may be sent and/or received. An operable connection may include a physical interface, a data interface and/or an electrical interface. 
     Computer system  600  may include a display interface  602  that forwards graphics, text, and other data from the communication infrastructure  606  (or from a frame buffer not shown) for display on a display unit  630 . Computer system  600  also includes a main memory  608 , preferably random access memory (RANI), and may also include a secondary memory  610 . The secondary memory  610  may include, for example, a hard disk drive  612  and/or a removable storage drive  614 , representing a floppy disk drive, a magnetic tape drive, an optical disk drive, etc. The removable storage drive  614  reads from and/or writes to a removable storage unit  618  in a well-known manner. Removable storage unit  618 , represents a floppy disk, magnetic tape, optical disk, etc., which is read by and written to removable storage drive  614 . As will be appreciated, the removable storage unit  618  includes a computer usable storage medium having stored therein computer software and/or data. 
     In alternative aspects, secondary memory  610  may include other similar devices for allowing computer programs or other instructions to be loaded into computer system  600 . Such devices may include, for example, a removable storage unit  622  and an interface  620 . Examples of such may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an erasable programmable read only memory (EPROM), or programmable read only memory (PROM)) and associated socket, and other removable storage units  622  and interfaces  620 , which allow software and data to be transferred from the removable storage unit  622  to computer system  600 . 
     It should be understood that a memory, as used herein may include volatile memory and/or non-volatile memory. Non-volatile memory may include, for example, ROM (read only memory), PROM (programmable read only memory), EPROM (erasable PROM) and EEPROM (electrically erasable PROM). Volatile memory may include, for example, RAM (random access memory), synchronous RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), and/or direct RAM bus RAM (DRRAM). 
     Computer system  600  may also include a communications interface  624 . Communications interface  624  allows software and data to be transferred between computer system  600  and external devices. Examples of communications interface  624  may include a modem, a network interface (such as an Ethernet card), a communications port, a Personal Computer Memory Card International Association (PCMCIA) slot and card, etc. Software and data transferred via communications interface  624  are in the form of signals  628 , which may be electronic, electromagnetic, optical or other signals capable of being received by communications interface  624 . These signals  628  are provided to communications interface  624  via a communications path (e.g., channel)  626 . This path  626  carries signals  628  and may be implemented using wire or cable, fiber optics, a telephone line, a cellular link, a radio frequency (RF) link and/or other communications channels. In this document, the terms “computer program medium” and “computer usable medium” are used to refer generally to media such as a removable storage drive  680 , a hard disk installed in hard disk drive  670 , and signals  628 . These computer program products provide software to the computer system  600 . Aspects of the disclosure are directed to such computer program products. 
     Computer programs (also referred to as computer control logic) are stored in main memory  608  and/or secondary memory  610 . Computer programs may also be received via communications interface  624 . Such computer programs, when executed, enable the computer system  600  to perform various features in accordance with aspects of the present disclosure, as discussed herein. In particular, the computer programs, when executed, enable the processor  604  to perform such features. Accordingly, such computer programs represent controllers of the computer system  600 . 
     In variations where aspects of the disclosure are implemented using software, the software may be stored in a computer program product and loaded into computer system  600  using removable storage drive  614 , hard drive  612 , or communications interface  620 . The control logic (software), when executed by the processor  604 , causes the processor  604  to perform the functions in accordance with aspects of the disclosure as described herein. In another variation, aspects are implemented primarily in hardware using, for example, hardware components, such as application specific integrated circuits (ASICs). Implementation of the hardware state machine so as to perform the functions described herein will be apparent to persons skilled in the relevant art(s). 
     In yet another example variation, aspects of the disclosure are implemented using a combination of both hardware and software. 
       FIG. 7  is a block diagram of various example system components that may be used in accordance with aspects of the present disclosure. For example, the various components may be within the operating environment  100 , or only some of the components may be within the access control system  102 , and other components may be remote from the access control system  102 . The system  700  includes one or more accessors  760 ,  762  (also referred to interchangeably herein as one or more “users” or persons seeking to gain access to a location) and one or more terminals  742 ,  766  (such terminals may be or include, for example, various features of the access control system  102 ). In one aspect, data for use in accordance with aspects of the present disclosure is, for example, input and/or accessed by accessors  760 ,  762  via terminals  742 ,  766 , such as personal computers (PCs), minicomputers, mainframe computers, microcomputers, telephonic devices, or wireless devices, such as personal digital assistants (“PDAs”) or a hand-held wireless devices coupled to a server  743 , such as a PC, minicomputer, mainframe computer, microcomputer, or other device having a processor and a repository for data and/or connection to a repository for data, via, for example, a network  744 , such as the Internet or an intranet, and couplings  745 ,  746 ,  764 . The couplings  745 ,  746 ,  764  include, for example, wired, wireless, or fiber optic links. In another example variation, the method and system in accordance with aspects of the present disclosure operate in a stand-alone environment, such as on a single terminal. 
     The aspects of the disclosure discussed herein may also be described and implemented in the context of computer-readable storage medium storing computer-executable instructions. Computer-readable storage media includes computer storage media and communication media. For example, flash memory drives, digital versatile discs (DVDs), compact discs (CDs), floppy disks, and tape cassettes. Computer-readable storage media may include volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, modules or other data. 
     It will be appreciated that various implementations of the above-disclosed and other features and functions, or alternatives or varieties thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.