System and method for detecting presence within a strictly defined wireless zone

A wireless proximity detection system employs short-range wireless communication to detect the proximity of a user device within a strictly defined wireless zone and as a result trigger a desired action. The proximity detection system may utilize one or more leaky feeders to define the wireless zone and the associated received signal strength(s) detected by the user's wireless device. Alternatively, a compact planar antenna structure coupled with a highly shielded radio transceiver is used to allow a similar precise low-power radio beam to be emitted defining a small location to enable identification of a wireless device such as a smartphone in a given area in front of the device. The planar antenna structure allows a compact and low-cost fabrication method and the use of common printed circuit fabrication methods provide an integrated solution.

FIELD OF THE INVENTION

The present invention generally relates to a combination of a radio transceiver, a coaxial, planar or other antenna structure and antenna beam directivity manipulation for allowing a system to narrow down the position of a smartphone or other wireless device to a given radiation zone for the creation of an authentication of a transaction in only a limited and specific area.

BACKGROUND

Smartphone adoption in the United States has grown rapidly from less than 6% of the population in 2007 to nearly 80% of the population today. Currently, smartphones are being used for payment, GPS tracking, music streaming, access control, security and a wide range of other purposes unrelated to traditional telephony. Such widespread use by consumers, travelers and employees provides numerous opportunities for businesses, government and facilities to passively identify and/or interact with these devices and their user. However, very few uses have gone so far as to utilize smartphones (or other similar devices) to determine a user's presence within a strictly defined wireless zone by using purposely built antennas.

As one specific example, major hotel chains have invested tremendous assets in programs which allow them to better understand the needs of travelers and to make their stay as streamlined as possible. For instance, some hotels provide express check-in for a select set of their guests, while others provide check-in/check-out over the Internet or via a computer kiosk located in the hotel lobby. Others even allow the use of a smart phone as the hotel key. While these advances have certainly increased the occupancy rates of the various major hotel chains, they have not addressed the primary security issue, which is to ensure that the user's smart phone is located in a strictly defined zone outside the room where the user is clearly seeking to gain entry into his/her room. This is to the exclusion of the user's phone merely being adjacent to the room, such as while waiting for the elevator or while walking past their room.

Similarly, these issues can be found in numerous other situations. Thus, this disclosure is applicable in all areas where the detection of an identifiable customer, employee or other individual within a specific zone enables one or more desired or secured action(s), such as entrance or access to a structure, vehicle, venue, or any other type of restricted area, the adjustment of a desk, signage, or computer workstation to a user's preferences or for marketing purposes. In addition to these types of actions, smartphone utilization for payment and transactions has seen an important growth in acceptance and the use of near-field communication has traditionally been used to enable these types of transactions (e.g. tap to pay credit cards). For sales transactions, such as a coffee purchase or fast-food items, the use of the proximity of a smartphone to a vending machine or sales counter may be sufficient to authorize a sales transaction without needing the buyer to get their smartphone out of their pocket or add another layer of confirmation to the transaction, provided that the user is identified as being in close proximity of the vending machine or sales counter during the transaction which is vetted by electronic means like a token exchange. Alternatively, the near presence of a known wireless device may serve as a two factor authentication for a credit card transaction or the like. In another form, the presence of an authorized or expected wireless device may serve as an airline ticket, concert ticket or the like. The systems disclosed herein seeks to accomplish this type of transaction (hereinafter called “StrictID” or the “StrictID system”). In addition, other potential and non-limiting applications will be discussed herein.

DETAILED DESCRIPTION

Many systems exist which attempt to identify the presence of a user or wireless device within a large and loosely defined area. For example, Apple's iBeacon® technology is frequently utilized to detect a user's presence within a general wireless area and trigger advertisements, gather information from visitors to a store, and track the flow or workers within an office environment. However, all of this done using standard omni-directional antennas and thus the traditional transmission range of the device serves to define the area in which these actions take place. While this is suitable for triggering ads or other actions where greater granularity than a general proximity is not required, many useful and desirable actions simply cannot be taken as the zone cannot be sufficiently well defined. For example, the prior art systems are unable to define a wireless transmission zone so as to accurately detect the specific user at the front of a line, a user seated at a selected desk, a user standing in front of a kiosk or vending machine, or the like. The prior art systems would recognize one or more other users who were also present in or around the intended area and thus the system would be ineffectual for such an application. The prior art will also leverage the use of multiple beacons and power levels among a group of beacons as means to approximate location of users. The various attenuation effects of the body, antenna polarization make those methods accurate only to a few meters and the installation, setup and parametrization of the system is complex.

Many radio systems nowadays, including cellular and smartphone radios, integrate processing capabilities and can support very popular protocols like Bluetooth Low Energy which is a very common standard supported by almost all smartphone devices. Most of those radio systems are built around a System-on-chip radio that incorporates a central processing unit and an advanced radio transceiver in a very low-cost and integrated package. Conventional usage of these integrated circuits combines the system-on-chip transceiver with a ceramic antenna or a printed monopole or dipole antenna. The general objective is to maximize the antenna matching to maximize the range and consequently the achievable distances. The Bluetooth Radio Subsystem typically emit power levels varying from +4 dBm to −30 dBm under software control resulting in distances varying from a few meters to 100 meters or more. Using standard antennas for this purpose makes it difficult to know if a user is in front of the device as most of the common antenna topologies provide an omnidirectional radiation pattern. Even setting the lowest radio power output, common antennas structures will create a connectivity bubble around the unit that show no directivity properties.

To provide for this improved level of granularity in defining a wireless zone, and to avoid the detection of multiple users when only one is intended, an embodiment of the present invention may utilize one or more leaky feeder antennas. A leaky feeder is particularly useful in the present application as, despite their intended purpose for distributing RF absent directionality along a lengthy run, such as in a mineshaft or an aircraft compartment, it has been discovered that they may be modified for an alternative use in creating highly confined and restricted radiation patterns of varying sizes which enable the creation of a small tailored zone, such as a strictly defined wireless zone. In this application, contrary to the conventional long-run usage of a leaky feeder, there is typically no need for a line amplifier as the amount of signal leakage over the relatively short length is minimal. The structure also allows daisy chaining of those antennas as most of the power is maintained in the antenna and terminated.

At a broad level, the novel proximity detection system described herein attempts to overcome this omnidirectional antenna structure and permit the detection of a user's entrance into a strictly defined wireless zone using a wireless device and have one or more desirable actions automatically taken on the user's behalf as a result. In addition to the workplace and transactional embodiments described herein, it will be appreciated that similar embodiments of the proximity detection system to be described may also encompass systems application in the lodging and/or retail space as well as for triggering/controlling other desired actions in other fields and that the system is not limited to the various exemplary applications described herein.

Illustrated inFIG.1is a generic implementation of the StrictID system comprised of one or many connected devices that include a radio subsystem20capable of communicating with the wireless user device22, such as a smartphone of user30when the user30enters a radio zone42created by an antenna40which has directivity properties.

The invention addresses at least two core objectives to provide a more strictly defined area of radio energy concentration:A) The first objective is to radiate power to a level which is near the sensitivity threshold of most cell phone Bluetooth Low Energy receivers (typically in the −90 dBm to −100 dBm range). Some examples of Bluetooth Low Energy transceivers are the nRF52832 from Nordic Semiconductor, but any other transceivers can be used in this invention provided that they are operating in the same frequency band tuning of the antenna structure (noting that the leaky feeder structures are inherently wideband and minor changes to the slots can re-calibrate the radiation patterns for other frequencies like 900 MHz or 5 GHz) and that they are matched to the characteristic impedance of the structure. The antenna slot structure and pattern is set such that at around 1 meter of distance, the received signal strength is in the order of −90 dBm. Software algorithms may further manipulate the thresholds to adjust each chipset and compensate for the last few dBm of sensitivity variance in cell phone chipsets variations of technology Furthermore, the integration of common Bluetooth radios require no complex manipulation or attenuation of the transmitted power as the inherent low antenna efficiency of the leaky feeder ensures that only a small portion of the inbound signal is emitted at the antenna openings. As such, most of the power continues in the antenna structure allowing the daisy chaining of antennas as inFIG.9.B) The second objective is to create a compact antenna that will focus the energy in a desired narrow beam in front of the identification device. One approach used to leverage the ability to control slot patterns52in a leaky feeder type antenna52to create lobe patterns that enhance the directivity of the antenna as shown inFIG.2A. The antenna pattern for a 4-slot leaky feeder antenna52viewed from above is illustrated inFIG.2B. As can be seen, this antenna design produces a single radiation lobe that has strong forward lobe42and a less substantial back lobe44radiation pattern (a relatively good front-to-back ratio in antenna terminology).

The rationale to create a very weak radio zone rather than rely on strong beam directivity is that in most environments, metallic structures (concrete reinforcements, support beams, metallic fire door) will redirect (bounce) enough energy between the user's smartphone22and the radio system50such as to create connection link that can end up in different locations than the required area. A radio signal loses quite a bit of strength if it bounces off a metallic structure and thus starting with a very low signal emitted from the antenna will significantly reduce or eliminate the odds of creating out-of-zone persistent connections.

In some variants of the system, the antenna structure comprising of the feed port43, the leaky feeder antenna52and a termination45matching the characteristic impedance of the structure is structured to create a precise beam of low radio power illuminating an area of interest42for detection of users30and their smartphones22.

It is important to emphasize that the antenna structure is constructed to be of low radiation efficiency allowing typical radio transceivers to be used with their common output power levels varying between −20 dBm and +4 dBm directly feeding into the antenna structure. Most of the energy will end up dissipated at the end of the leady feeder antenna in the termination45. The radiated power is very low due to the low radiation efficiency of the structure, but allow scalable systems to be constructed out of the same line as most of the RF wave power remains until the termination.

The overall radio circuit50needs to be strongly shielded for proper operation of the system. The StrictID system may include a full cage shield over the radio components and the PCB layout will include strong shielding precautions as to avoid any leakage of RF signal from the radio circuit to its surrounding environment. The intended low level of emissions is only to be at the antenna radiation slots54.

In the form illustrated, antenna40is in the form of a leaky feeder52. Leaky feeder52is an adaptation of a standard round coaxial cable where the outer conductor intentionally includes one or more gaps or slots or cut holes (collectively “gaps”)54which allow the structure to radiate in a controlled manner. Electromagnetic waves propagate through the dielectric within the cable, with currents running along the inner and outer conductors. These waves can “leak” through the gaps54in the outer conductor. This makes this structure act like a slotted waveguide antenna, since the coaxial feeder cable can be seen as a particular type of waveguide. In a normal coaxial cable this is, of course, unintended behavior, however this is what allows the leaky feeder52to act as an antenna. In one form, leaky feeder52is less than 5 feet in length. In a further form, leaky feeder52is less than 2.5 feet in length. In a still further form, leaky feeder52is less than 1 foot in length. In yet another form, leaky feeder52is less than 4 inches in length.

The construction of the leaky feeder52can be done with common coaxial cables structures with solid shields for ease of machining. Typical examples of such coaxial cables that were used include Heliax 0.5 inch 50 ohm that were machined on the corrugations in a process similar to the manufacturing of leaky feeder coaxial cables used in underground mines for radio propagation over long distances in tunnels. Smaller diameter antennas were also machined from RG401/U coaxial cable which has a solid and smooth shield which was easier to machine precisely. Finally, a structure similar to coaxial cable can be emulated using PCB material and conductive layers for very compact ‘leaky antennas’.

In another embodiment, according toFIG.3, one specific application of a proximity detection system21is shown which enables a user (such as an employee) using his/her wireless device22to have one or more desirable actions taken on the user's behalf, such as automatically logging the user into a computer workstation60(or have one or more steps thereto performed), adjusting the height of desk70and/or automatically performing one or more other desirable actions by simply entering a strictly defined wireless zone80. In the preferred form, the employee's wireless device22is a Bluetooth® capable phone24or other wireless token or appliance. In other forms, the wireless device22is an electronic device capable of short range wireless communication, such as a device implementing Bluetooth®, Zigbee® or some other low-power wireless communication protocol/standard. In an alternate form, the user's wireless device22may be in the form of a dedicated wireless token. In one form, the user's wireless device22may include an installed application or other installable and/or dedicated software or circuitry which enables it to be detected (or discoverable) by the remainder of proximity detection system21as is known in the art.

In the illustrated embodiment, computer workstation60and desk70collectively form an area for an employee to sit and work, such as is common in an open office or flexible office layout. In this form, the computer workstation60and desk70are not typically assigned to a selected user, but rather are available for use by anyone on a first come first serve basis. Workstation60rests on desktop or desk70, which is shown in the illustrated embodiment as being a traditional rectangular shape, having both a front72and back74. Desk70also includes a motorized height adjustment mechanism (not shown), as is known in the art, such as that available from Steelcase Inc. in its Series 3, Series 5 and Series 7 height-adjustable desks. Computer workstation60may be a traditional desktop computer, a thin client, a laptop computer, a telephone terminal, a cash register or any other type of computing device known in the art. Desk70may also include a chair (not shown), such as for use by a user utilizing computer workstation60and/or desk70.

Defined in proximity of the desk70, in the area where a worker or employee would sit or stand to utilize computer workstation60, is a strictly defined wireless zone80which is bounded by logical boundaries80a,80b,80cand80d. Wireless zone80is defined by the radiation patterns of leaky feeder antenna52which is mounted on, integrated in or otherwise located adjacent to wireless zone80. Physically, the radiation pattern of the leaky feeder antenna52does not look like a square and will go over logical boundaries80band80dbut, by the means of software algorithms, the actual “detection” zone will more or less have a quadrilateral (trapeze) shape for its effective area like wireless zone80shown inFIG.1. The radiation that goes over the strictly defined area is likely to be very low in power in a way that it is very difficult to pick up any signal with a smartphone.

As shown inFIG.3and in detail inFIG.4, in this embodiment the leaky feeder52is mounted to the front vertical surface of desk70. In a further form, the leaky feeder52may be inset slightly or completely within the front face72of table70. Leaky feeder52is shown without its optional external covering or sheath inFIG.4for purposes of illustration of its internal functional structure. In the form illustrated, leaky feeder52may be an adaptation of a standard round coaxial feeder cable where the outer conductor intentionally includes one or more gaps or slots or cut holes (collectively “gaps”)54which allow the structure to radiate, as further described above. The presence of dielectric material in front of the leaky feeder antenna such as a melamine layer or plastic protection minimally affects the radiation pattern and thus the antennas can be embedded within the construction of the desks to simplify the installation of the StrictID system.

In one form, the creation of the leaky feeder52consists of cutting gaps54of the right pitch and width to create the intended radiation pattern. In the illustrated embodiment, the gaps54are created on only one side of leaky feeder52so as to create a directional antenna. In one form, the pattern of gaps54in the leaky feeder varies along its length. In another form, the pattern of gaps54in the leaky feeder is different at ends52aand52cof the leaky feeder52than it is at the center of leaky feeder52, with this different pattern designed to create destructive interference in those areas and thus the sharp cut off desired for strictly defining wireless zone80and angles between boundaries80a-d(specifically for boundaries80aand80cshown inFIG.3). The pattern may include at least the size, shape, spacing and/or orientation of the gaps54. In one form, the leaky feeder52is created by placing additional shielding over a conventional leaky feeder. Generally, a single array of 3 to 4 slots provided a good antenna beam with the slot pitch and length having an effect on the antenna efficiency or symmetry of the antenna beam. Anyone skilled in the art of making antennas will understand that the method presented here of machining slots in the coaxial cable to make the antenna can be optimized to manipulate the beam pattern without changing the main objectives that are the creation of a precise radiation lobe defining the strict identification location zone (equal power zone)80in front of the antenna. Other coaxial cables structures or waveguides may be used to create the antenna provided that the main concept of this invention is retained, that is to be of low radiation efficiency and shape a defined zone of the antenna with a very low radiated power.

Alternatively, the leaky feeder52may be specifically manufactured as a custom leaky feeder having gaps of the desired size and orientation in the desired location along its length. In addition, the transmission power applied to the leaky feeder52may be modulated so as to achieve the desire radiation depth (and thus define boundary80bshown inFIG.3). The leaky feeder52may be manufactured from a coaxial cable having a round shape, or some other traditional construction or they may alternatively be manufactured from a flat or ribbon type material so as to be more easily and/or discretely mounted to or inset within the desk70ofFIG.3or elsewhere as desired.

The leaky feeder52serves to define wireless zone80as the area in which a wireless device, such as wireless device22or user phone24, will detect a received signal strength indicator (RSSI) above a predetermined threshold. The wireless zone50is defined by the orientation of the leaky feeder52, the pattern of gaps54and the resulting radiation pattern of the leaky feeder52, the surrounding environment and the transmission power applied to the leaky feeder52, such as by a transmission source (shown inFIG.5). The wireless zone50shown inFIG.1is considered to be “strictly defined” in that it falls off sharply when compared to a traditional wireless signal along at least two sides of its defined area. This is ensured by having a single frontal lobe with monotonically decreasing power with angle and restricting as much as possible the appearance of frontal spurious lobes. The wireless zone50shown inFIG.1is considered to be “strictly defined” in that it falls off sharply when compared to a traditional wireless signal along at least two sides of its defined area. In one form, a strictly defined wireless zone may include a depth of no more than 5 feet. In a further form, the strictly defined wireless zone may include a depth of no more than 3 feet. In a still further form, the strictly defined wireless zone may include a depth of no more than 1 foot. Alternatively or additionally, the strictly defined wireless zone may include a width of no more than 5 feet. In a further form, the strictly defined wireless zone may include a width of no more than 3 feet. In a still further form, the strictly defined wireless zone may include a width of no more than 1 foot. In the illustrated embodiment, these sharp boundaries would include the sides80aand80c. It shall be appreciated that leaky feeder52may be mounted at other locations within or on desk70while still providing the desired definition of wireless zone80. In a further form, the desk70may include a cover so as to aesthetically hide the leaky feeder52from view. The optional cover is preferably made from a durable yet sufficiently RF transparent material such as fiber mesh, cloth, plastic or the like. The description does not restrict the mounting options and it is possible to use the legs of the desk to host an antenna provided that they do not interfere with the antenna operation.

Shown inFIG.5is a plan view of the proximity detection system21ofFIG.3which includes other items. Included are wireless device22, computer workstation60, desk70and leaky feeder52. Also illustrated are access point92, control server94, database96, transmission source98and table control unit99, two or more of which may be interconnected by network pathway(s)90. In the illustrated form access point92is a wireless access point, such as a wireless router, providing a wireless network with optional mesh capabilities (Bluetooth® or Thread, IEEE 802.15.4) and internet access under the 802.11 standard. This network connection may be utilized by the remaining devices within system21to communicate and/or to supplement their own cellular or other communication networks. It shall be appreciated that one or more devices shown inFIG.5may be located remotely from each other, such as in an arrangement where control server94and/or database96are located remotely or operating in the cloud.

In this embodiment, control server94operates in conjunction with access node92over the internal network to communicate with user device22as well as table70, and its transmission source98and control unit99, in order to carry out the desired method. In one form, when a user device22comes within range leaky feeder52it has or begins communications with control server94to determine its presence (or lack thereof) within wireless zone80ofFIG.5. This may be accomplished via the use of a coded signal emitted by the leaky feeder52which is then received by the user device22, as will be described herein. Control server94utilizes database96for storing records identifying all of the various actions that may be triggered by a user when present within any of a number of defined zones. For instance, control server94may store a list of users authorized to utilize computer workstation60and/or table70, as well as their log in information, preferences, and desired table settings (such as height, lighting, etc.). Accordingly, upon determining that user device22is within the wireless zone80, control server94may initiate the desired actions. While control server94is described and illustrated as being a server, it should be understood that control server94may be any computer, including a client server arrangement or a program on a workstation. Server94may interface with any of the other components of system21by either a wireless or hardwired interconnection. Preferably, the connection is a secured connection. A non-limiting example list of potential interfaces includes IR, optical, RF, serial port, IP network, and USB. Additionally, the functions of control server94, access node95and/or database96may be integrated into one computer system or other dedicated hardware.

In addition, in this embodiment, table70also includes a transmission source98and control unit99. The transmission source provides a desired signal of the appropriate strength to the leaky feeder52. Attenuators can be used in series in the RF path to modulate the power getting to the leaky feeder antenna52if necessary. In addition, appropriate shielding may be provided, as described with respect toFIG.1. The settings of the transmission source98may be communicated to it by control server94, via either a wireless or wired connection. Alternatively, these settings may be hard coded into the transmission source98. Control unit99is a standard control unit for controlling the height and other settings (if any) of a height adjustable table70, as is known in the art. However, control unit99may be enhanced in that it is configured to accept remote commands from control server94, either by wireless or wired connection, so as to enable control server94to adjust the settings of the table dynamically based upon the detection of an identified user within the wireless zone80and that user's pre-selected preferences.

Turning toFIG.6, yet another embodiment of proximity detection system including a plurality of leaky feeders152a-din order to collectively and more precisely define a wireless zone150is illustrated.FIG.6shows another proximity detection system120in shown which enables a user (such as an employee) using his/her wireless device122to have one or more desirable actions taken on the user's behalf, such as automatically logging the user into a computer workstation130(or have one or more steps thereto performed), adjusting the height of desk140and/or automatically performing one or more other desirable actions by simply entering a strictly defined wireless zone150. In this embodiment, computer workstation130rests on a desk140which is in the shape of an “L”. Many of the other devices are similar to that described with respect toFIGS.3-5, however the system120utilizes two or more leaky feeders152aand152bin order to more strictly define wireless zone150, which is again defined in proximity of the desk140, in the area where a worker or employee would sit or stand to utilize computer workstation130. Specifically, in this embodiment, leaky feeders152aand152bdefine their own wireless zones154aand154brespectively. However, by requiring presence in both of these wireless zones154aand154b, system120is able to define strict wireless zone150which is defined as the intersection of wireless zones154aand154b. Wireless zone150is bounded by logical boundaries150a,150b,150cand150d, however, in one form each of those boundaries is now influenced by one end of a leaky feeder and its associated sharp signal drop off attributable to destructive interference. For example, in one form leaky feeder152ais given a greater weight in the definition of boundaries150band150d, while leaky feeder152bis given a greater weight in the definition of boundaries150aand150c. This provides for a sharper cut off than merely utilizing the transmission power provided to the other leaky feeder to regulate this dimension of the wireless zone50. It shall be appreciated that more than two leaky feeders may be utilized to further define a wireless zone, including the use of a leaky feeder facing upward or downward to provide a strict three dimensional definition of wireless zone50. Moreover, leaky feeders152cand152dmay be utilized to define negative wireless zones154cand154dwhich define areas which would block a determination that the wireless device is within wireless zone150. These negative zones may be utilized to provide increased accuracy, to prevent false positives or to overcome issues raised by the specific environment in which the system120is implemented. In another form, the one or more additional leaky feeders may be oriented on the back of desk140, such as in a 180 degree opposite direction of leaky feeder152aand/or152b, so that they can be used comparatively to prevent false positives resulting from issues with back lobes, reflectivity or the like.

As is shown inFIG.2B, the leaky feeder52typically has a back lobe44which in some applications like back-to-back countertops installations increases the possibility of false detections due to one antenna receiving signal from the back side. In some embodiments, as shown inFIG.7, the leaky feeder52may be protected by an outer shell56made of RF transparent material, typically ABS or PVC. The insertion of a small foil58or some other RF blocking/reflecting material inside the PVC tube at a constant distance from the leaky feeder52away from the radiating slots improved the front-to-back ratio significantly.FIG.7shows a cross-section of the resulting structure according to this further embodiment when the leaky feeder52is inside a protective sleeve56and includes an RF blocking and/or reflecting back portion58. This reflector addition can be achieved with adhesive backed aluminum tape or copper tape with little change to the desired performance of the antenna. At the operating frequencies, the skin depth is small, thus other flexible materials capable of being metallized and applied in the back side of the leaky feeder52would also improve the front to back ratio.

In an embodiment, the use of highly effective EMI shielding material comprised of metalized polyamide, for example, can create a boundary condition that when such a sheet placed at some short distance off the back of the leaky feeder antenna (but still in the near field region) and inside the StrictID system significantly decreases the back lobe (by 10 dB or more) thus reducing the back lobes which are an unavoidable due to the physics. The use of this shielding material assists in reducing the back lobes to some extent.

In other instances, such as highly dense venues where multiple users can queue, the use of RF absorbent fabric usually made of a polyester base with a few silver-plated copper threads or conductive carbon threads, the use of a small curtain will add the necessary attenuation between closely spaced service desks to eliminate possible cross talk between waiting queues.

A flowchart illustrating one set of steps performed in configuring a user device24for use with a proximity detection system21according to one embodiment of the present invention is shown inFIG.8. The process involves a wireless token24and the various other components of access system21. The following description is with continuing reference to access system21ofFIGS.3-5. It shall be appreciated that initial registration and configuration information must be populated within database96(or control server94) to enable to methods described herein to be performed. For example, confirmation information stored by control server94within database96preferably identifies each wireless zone80and any associated actions or related devices (such as computer workstation60and desk70in the case of wireless zone80). Other information stored by database96includes a unique identification for the computer workstation60, an identifier of table70and a communication address for its control unit99as well as the user and his/her associated user device22(such as by MAC address, EIN or the like). Various security measures may also be are implemented to secure this information.

Other information included within database96are the user's desired actions for each of one or more wireless zones, such as wireless zone80, and preferences associated with each of those actions. For example, a user may be associated with a user device22. That user may also have his/her log-in information for computer60stored within database96. That user may also have preference information stored for the preferred height of desk70within the range of heights available. When desk70is so equipped, preference information regarding the lighting (including on/off, color temperature, brightness) etc. may be included. In the preferred form, this information is received by control server94as a result of an initial configuration of the owner/operator of the equipment and the users enabled to access it.

As shown inFIG.8, the process begins at start point800with the user along with the user device22arriving in a location within range of an access node92but outside of the wireless zone80(step802). In step804, user device22detects the access node92. Upon this detection, the access node determines whether or not the user is registered and/or authorized to trigger desired actions upon detection in one or more of the wireless zones80(step806). If the user device22does not match an entry in the database96, the process ends at point808. If the user device22is authorized, access node92will allow the user device22to maintain a connection (step810). In step812, access node92communicates with software on user device22to enable user device22to identify signals from leaky feeder52. In step814, user device22is moved within range of leaky feeder52, but remains outside of wireless zone80. In response to the signals received from leaky feeder52, user device determines the strength of the signal and reports it to the access node92(step816). Using a predetermined signal strength threshold, control server94determines that user device22is not within wireless zone80(step818). No further action is taken as the condition precedent of presence in the wireless zone is not met. In step820, the user device22is moved into the wireless zone80. User device22again receives signals from the leaky feeder52and in response it again determines the strength of the signal and reports it to the access node92(step822). Using a predetermined signal strength threshold, control server94determines that user device22is within wireless zone80(step824). Given the satisfaction of the condition precedent, control server94initiates the performance of the desired actions stored in database96in conjunction with the user associated with user device22and wireless zone80(step826). In this case, by way of example, that may be to automatically log the user into computer workstation60and adjust the height of desk70to setting “6”. In one further form, the control server94may communicate its determination that user device22is within wireless zone80back to user device22, and may enable a graphical presentation on user device22to enable the user to affirmatively select which, if any, of the desired action stored by database96that it would otherwise automatically trigger. In an alternate form, the control server94may consider the current occupancy of the wireless zone80when performing the evaluation of step822. For example, if a user is already within the zone and logged in and a second user stops by to visit, in order to prevent a different action from occurring, the system21may require the vacation of the zone by the first user before recognizing a second user or the system21may require approval of one of both of the user's via their user device's prior to taking an action in such a situation. In another form, the control server94may require the presence of any user within the wireless zone for a set period of time before taking step826, so as to prevent false positives. The process ends at end point828.

It shall be appreciated that many of the steps described herein shall similarly be usable or adaptable for use with the proximity detection system120ofFIG.6. In such instance, steps816and818and steps822and824would each require a two-step process in order to ensure that the user device22is within each of the zones154aand154bdefined by leaky feeders152aand152ato confirm the user devices presence within wireless zone150. A failure of either of these zones154aor154bwould result in a determination that the wireless device22is not within the wireless zone150. In a further form where negative zones are defined (such as zones154cand154dofFIG.6), a similar step would need to be implemented in order to ensure that wireless device22is not determined to be within one of those zones prior to proceeding.

It shall be appreciated that other devices and/or environments, such as access control, vending machines, conference rooms, thermostats, lamps, televisions, kiosks, automated teller machines, check-out terminals, gas pumps, car washes, workout stations/equipment, fast-food drive-thru, automobiles, ticketing and many others may benefit from the application of the present invention. Examples may include having the system trigger certain of these steps automatically, such as attendance registration, channel selection, order placement, display of favorite options or other customizations or preferences applied thereto.

The use of multiple daisy chained antennas or leaky feeders52is also possible to extend the detection locations of the users within the same radio subsystem. Since most of the input power passes through the coaxial line without much loss (only cable losses and some small portion of radiation loss), the system can be extended with regular coaxial cables and terminated at the end of the chain. This topology of multi-zone identification can be used to track people as they advance in long linear queues, such as waiting for an attraction in a theme park, waiting to board an airplane or waiting to order at a coffee shop, as just a few representative examples. Using multiple radio systems50and antennas40to form multiple chains with non-overlapping beams (or not depending on the application) can help track users30of the system in longer queues as shown inFIG.9.

Alternative antenna designs may also be utilized in place of or in conjunction with the leaky feeder antenna52ofFIGS.2-7and to achieve a similar radiation pattern(s) to that desired and described herein above. The use of machined coaxial cables to build antennas provides great results and could be used in production in certain circumstances. However, to optimize the fabrication cost and aesthetics appeal and reduce the space requirements, the leaky feeder antennas52described thus far may also be converted to a planar structure while preserving the desired beam pattern and retain the low radiation efficiency characteristics of the coaxial solution.

FIG.10illustrates the topology and design elements of an alternative compact and integrated antenna design100which is operable as a leaky feeder. The overall planar StrictID circuit and antenna integration100includes the same radio subsystem50as in the prior embodiments, but the cylindrical leaky feeder antenna52has a planar structure102.

The planar embodiment shown inFIG.10may include a secondary conventional high-efficiency antenna104(ceramic, PIFA, dipole or similar) that is internally multiplexed with the leaky antenna102to allow multiple StrictID to operate as a cluster via mesh or star networking under software control.

To build the antenna100of the planar leaky feeder embodiment,FIG.11shows the cross section of laminated structures used to build a common 4 layer printed circuit board with the conductive copper layers being 205-208 and the dielectric layers being 209-211. The intent is to use conventional FR-4 PCB substrate laminations including core dielectric and prepregs to realize the leaky antenna. It is possible to use RF dielectrics such as Rogers RO4350 or any similar high-performance dielectric material to construct the antenna structure, but the overall goal being to create a low-cost solution, conventional printed circuit board manufacturing techniques to incorporate both the radio circuitry and the antenna in a compact, low-cost and efficient to manufacture unit is likely to be preferred.

The dielectric stack ofFIG.11can be arranged to create a well-known topology called an asymmetric stripline, as is shown inFIG.12. The top205and bottom208copper structures of the 4-layer PCB will generally be used as the top and bottom shielding layers. Within the antenna structure, layer207will be removed leaving only 209 and 210-211 dielectric layers. The feed trace of the antenna will be constructed by the 206 copper layer. For 1.5 mm FR-4 PCB the typical antenna feed line will be around 370 um of width to obtain a 50 ohm characteristic impedance and will thus allow normal PCB fabrication techniques and processes to be used. The ideal construction would be a 3 layer PCB with the antenna feed right in the middle, but this is not a common PCB stack configuration on the market so generally a 4-layer solution is preferred. The feed line connects the shielded radio circuit50and the antenna102over a short distance that is shielded by the copper layers205and208.

In the antenna radiation zone102the series of copper opening slots205(4small slots is a good solution, but more or less slots can be created to modify the intended beam pattern) allow the RF energy to escape in a directed beam only at that point. Note that the overall circuit100size is important for the creation of a controlled radiation lobe.FIG.13shows two possible and useful radiation patterns (250and255) obtained with an antenna size (determined by the width of the back copper plane) varying between 60 mm in width and 100 mm in width obtained through manipulation of the number of slots and slot spacing. Similar to the leaky feeder52there is a fair amount of design space options possible to create a tuned pattern for a given application.

It is also possible to combine multiple antennas102on a common circuit100to create an enhanced and more accurate inside/outside detection of the user by combining the radiation pattern250and255in one single unit with multiplexed antennas. The multiplexing is usually controlled by software and can thus be made very quickly to change between antennas and based on the response from the user cell phone22interactions allow the user to be precisely located as shown in the hatched zone256ofFIG.8.

Note than inFIGS.13and14the view is from above the zone and the circuit100is seen from the side as if looking above the system. The radiation pattern is of equivalent signal intensity and does not reflect the radio range at scale. The complete circuit will generally measure approximately 60 mm-100 mm in width for operation in the 2.4 GHz ISM radio band and the radio range for a −90 dBm signal level will generally be adjusted to be around 1 meter through changes to the parameters of the transceiver power settings.

It should be noted that variants of higher layer count PCB structures or a lower count 2 layer PCB with soldered shield could be created to effectively create the same antenna structure as can be derived by anyone skilled in the art of creating low-cost PCBs. One could also construct the system ofFIG.10by soldering a separately built leaky slotted planar antenna on a circuit substrate100without changing the intent of the invention.

In a still further form, multiple StrictID components may be linked together with their secondary antenna104allowing multiple combinations of inside/outside detection and rejection based on the Boolean combination of antenna pattern and detection of the user's smartphone22in those zones. Those Boolean operations are likely to be realized on the server side as it simplifies the deployment of the StrictID system.

The applications for a StrictID system with a well-defined RF identification area are numerous. In their simplest form of a single StrictID assembly, a user enters the identification zone, for example in the ordering zone of a coffee shop. A connected terminal may rapidly identify the user and propose commonly purchased items and the preferred customer choices. The use of the StrictID system and its very limited connection zone will ensure that only one or at most 2 or 3 registered users can be detected in the small area near the ordering zone and the clerk serving the customer will have no difficulty identifying the person with a second factor such as mentioning the name or with a picture on file. For example, In addition to the user identification and/or authentication functions described herein, the system may also include a secondary user verification step. For example, an application on the user's smartphone22may collect biometric identifying information, such as by the use of Apple's Touch ID® or Face ID® systems for use within the StrictID system. Alternatively, other biometric sensors or cameras may be present within or proximate to the defined zone in order to secondarily authenticate that the registered owner of the detected mobile device is indeed present and that the mobile device has not been compromised. For example, transactions exceeding a set threshold, such as $50, may require this secondary verification.

A similar process can happen with another StrictID element located near the point of sale terminal to allow rapid self-checkout of the purchase (e.g. the coffee) and the user will simply have to stand in the StrictID RF illuminated area for a few seconds for the identification process to complete. Multiple similar small transactions scenarios where the user may have his hands full or would not want to remove e.g. his gloves to use the telephone to perform identification transactions.

Another use of those distributed and narrow beam antennas would be in car drive-through scenarios. By allowing the beams to enter the cars only in a defined zone (e.g. when the user is aligned with the ordering booth), the system will allow the identification process with the smartphone to be completed without the user having to get his phone outside the window of the card. In most smartphone RFID solutions relying on near-field communication, the distance to the telephone must be very short due to the physics and require the user to almost touch his smartphone to the reader. In cold locations, or to improve user experience the use of the added RF range offered by the StrictID approach will bring benefits.

The planar improvement benefits to the StrictID systems are further evident when one considers the integration of the authentication mechanisms in door frames, door panels or similar structures where the cylindrical nature of the leaky feeder52it not as easily adaptable. The ability to combine two antenna functions like the global antenna104and the local radiation pattern antenna102allows those variants of StrictID to detect the approach of a person like common far reaching RF identification solutions based on Bluetooth Low Energy and when the users reaches very close to the door, antenna102can ensure that the user is really close to finalize the unlocking of the door by way of another factor like a capacitive touch handle or similar.

The set of steps performed in configuring a user device24for use with a proximity detection system20inFIG.5. Could be applied to any of the other embodiments described inFIGS.6and/or13.

In one further form, shown inFIG.15, multiple antennas40may be utilized in a selective spatial arrangement to allow for the determination of an angle of arrival and/or angle of departure for a user, such as the user's arrival within a strictly defined zone81. In the illustrated embodiment, the antennas40are offset from one another by approximately ½ of a wavelength of the signal utilized. In the case of Bluetooth Low Energy, which has a wavelength of approximately 12.5 centimeters, this offset would be roughly 6.25 centimeters (or 2.5 inches). Using this configuration, the radio system51, which is operatively coupled to each of antennas40and is able to measure the phase difference in the inbound signal within the radio and may perform an angle of arrival or angle of departure calculation as described in the Bluetooth Core Specification Version 5.1, Vol. 1, Part A, pgs. 281-284. The resulting angle of arrival or angle of departure may be utilized in certain applications to ensure that a detected user came from the expected direction, such as in the case of a queue, or that a previously detected user has departed in the expected direction, such as when boarding a plane. Using this information may further assist an embodiment of the present invention in detecting and eliminating false positives or to enhance security, determine user order in queues while not having a dependency on only the radio strength signal which can vary between users due to attenuation, orientation and obstacles.

Persons familiar with the field of radio technology and latest advances in digital RF processing will understand that using soft-defined radios with synchronized ADCs working with digital I/Q demodulators will be able to determine the angle of arrival of signals using phase offset calculations when receiving the packets. While the StrictID system could draw major cost benefits from the use of low-cost implementation in chipsets implementing Bluetooth Core Specifications Version 5.1, soft-defined radio derivatives of the same idea or ones that can leverage multi-input multi-output (MIMO) receivers are also usable in the solution

The invention can leverage considerable benefits even with improvements to user location based on angle of arrival due to the physical proximity required to be authenticated. The StrictID solution ensures that the corresponding noise floor and the Bluetooth radios sensitivity make long-range or multipath detection much less likely to happen. The manufacturing process of leaky feeders, notably on planar substrates can be well controlled, is mechanically simple and tolerant to manufacturing variations. Furthermore, the use of multiple planar leaky feeders will still maintain the control on the radiation pattern.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all equivalents, changes, and modifications that come within the spirit of the inventions as described herein and/or by the following claims are desired to be protected. Hence, the proper scope of the present invention should be determined only by the broadest interpretation of the appended claims so as to encompass all such modifications as well as all relationships equivalent to those illustrated in the drawings and described in the specification.