Estimating a spatial property of a first device

Abstract

A first device, which is realized as a shelf mountable device, comprising at least two antennas (24, 25) for the purpose of estimating a spatial property of the first device, in particular in relation to a second device, preferably the at least two antennas are arranged in a horizontal distance (27) to each other when the first device is oriented in accordance with its intended use.

Description

[0001] TP0555

[0002] TITLE

[0003] ESTIMATING A SPATIAL PROPERTY OF THE FIRST DEVICE

[0004] DESCRIPTION

[0005] TECHNICAL FIELD

[0006] The invention relates to a first device , which is reali zed as a shel f mountable device and uses its antenna for the purpose of estimating a spatial property of the f irst device .

[0007] BACKGROUND

[0008] In retail or logistics , one of the technical challenges of indoor navigation is the identi fication of a direction from which the radio signal is received or in other words the identi fication of a direction from which the radio signal was sent out or origins . A possible approach would be to distribute a larger number of special detection devices , which are configured for detecting the direction from which the radio signal is received . In technical j argon such special devices are termed "angel of arrival" detector, in short AoA detector . Such an AoA detector comprises an antenna array and the electronics of such an AoA detector is configured for measuring the time di f ference of arrival of a radio signal ( TDOA) between individual elements of the antenna array . Hence , for such AoA detectors signal proceeding performance and highly synchroni zed processing of the individual received radio signals at di f ferent antennas are crucial .

[0009] Further to this , data generated by each induvial AoA detector must be sent via a data communication TP0555 2 network, either by radio or line , to a central processing unit where these data are further processed to support the indoor navigation . Hence , the use of AoA detectors amongst already exiting electronic retail equipment demands a further layer of electronic equipment , which must be installed, maintained and managed to include the AoA detectors . These circumstances are a signi ficant cost driver .

[0010] In conclusion, in retail or logistics the application of stand-alone AoA detectors and the use of data generated by it requires an extremely expensive separate infrastructure . Notwithstanding the high investments the results achieved by the AoA detectors have shown to suf fer from multipath and shadowing problems and may cause large locali zation error, which in turn leads to misleading navigation instructions causing frustration of the users of such technology .

[0011] Attempts to physically integrate such AoA detectors into decentrali zed electronic devices ( e . g . electronic display signs like electronic shel f labels or electronic video rails , etc . ) in a retailer or logistics environment has proven to be extremely undesired because it would require enormous investments in the re-design of such electronic devices and the required high-performance hardware would be an undesired cost driver for such electronic devices . Since many of the devices are battery-powered, the required signal or data processing would also result in an undesirable reduction in battery li fe , which conflicts with the basic idea of maintaining maintenance cycles for such devices as long as possible .

[0012] Therefore , the obj ective of the invention is to provide an electronic device for cost-ef fective , mass use , particularly in sales rooms and / or storage rooms of retailers and logistics centers , with the help of which at least an estimate of a radio signal direction TP0555 3 can be taken into account for further use , for example in indoor navigation applications etc .

[0013] SUMMARY OF THE INVENTION

[0014] This obj ect is achieved by a first device according to claim 1 . Therefore , the subj ect matter of the invention is a first device , which is reali zed as a shel f mountable device comprising : at least two antennas for the purpose of estimating a spatial property of the f irst device , in particular in relation to a second device .

[0015] Preferably the at least two antennas are arranged in a hori zontal distance to each other when the first device is oriented in accordance with its intended use .

[0016] This obj ect is al so achieved by a second device according to claim 14 . Therefore , the subj ect matter of the invention is second device , which is configured to transmit a radio signal between the first device according to the invention and the second device for the purpose of estimating a spatial property of the first device .

[0017] The obj ect is also achieved by a system according to claim 15 . Therefore , the subj ect matter of the invention is a system comprising at least one first device according to the invention and a second device according to the invention .

[0018] This obj ect is al so achieved by a method according to claim 16 . Therefore the subj ect matter of the invention is a method for estimating a spatial property of a first device , wherein the first device or a group of first devices comprises at least two antennas for the purpose of estimating a spatial property of the first device , in particular in relation to a second device , wherein the method comprises the following step :

[0019] - transmitting of a radio signal between the first TP0555 4 device or the group of first devices and a second device for the purpose of estimating a spatial property of the first device. Preferably the at least two antennas are arranged in a horizontal distance to each other when the first device is oriented in its intended direction .

[0020] Shelves are usually installed in a retailer's sales room or a logistics company's storage room. Each shelf has a number of shelf boards. Goods are stored on the shelf boards. Each shelf board has a front edge that is used to attach electronic equipment that realizes the first device.

[0021] The shelf-board may be oriented horizontally or slightly tilted forward to allow better visibility of the products placed thereon. In contrast thereto, the front edge of the shelf board is usually oriented horizontally, i.e., typically parallel to the floor of the sales room or the storage room, which is also usually horizontal. A horizontal direction therefore essentially extends along such a front edge of a shelfboard. The horizontal distance mentioned above is therefore measured along the horizontal direction, i.e., essentially along the front edge of the shelfboard or parallel to the front edge of the shelf-board. The meaning of a horizontal distance is therefore equivalent to stating that the at least two antennas are positioned in a horizontal offset to each other. Orthogonal to the horizontal direction, i.e., essentially perpendicular, is a vertical direction, which, for example, is usually oriented normally to the horizontally running floor in a room or on parallel to the gravitational acceleration.

[0022] Such a shelf with its shelf-board ( s ) may be realized as a stand-alone furniture. The shelf or the shelf-board ( s ) may be integrated into other furniture like freezer, refrigerator, display case, etc. TP0555 5

[0023] A so-called shelf rail is attachable to the front edge of a shelf-board, which facilities the mechanical connection of the electronic equipment along the front edge of the shelf-board. The electronic equipment usually has a mounting device on its rear side that allows it to be attached to the shelf rail. The mounting device is designed to complement that of the shelf rail. In some cases, the shelf rail can be omitted, and the electronic equipment can be attached directly to the front edge of the shelf-board because the electronic equipment itself has the appropriate mounting device configuration for direct attachment at the front edge of the shelf-board. The mounting device of the electronic equipment is therefore configured for this specific purpose. This type of configurations of the electronic equipment makes it suitable for shelf mounting (either indirectly via the shelf rail or directly) or in other words a shelf mountable device.

[0024] The mounting device and / or the shelf rail, or the interaction of these two elements, ensures that the electronic equipment in question can be mounted and consequently oriented there in accordance with its intended use. The outwardly visible orientation in accordance with the intended use is given, for example, when a screen is oriented in such a way that the information displayed on it can be read from left to right in accordance with customary practice, or when the upper or lower edge of the screen also runs horizontally. It can also be understood to mean that the usual orientation of top and bottom is to be understood in its natural interpretation in a sales room or storage room. The upper edge of the electronic equipment is then oriented upwards, i.e., specifically towards the ceiling of the room, whereas the lower edge of the electronic equipment is oriented downwards, i.e., specifically towards the floor of the room. The information indicating the correct orientation or TP0555 6 alignment for the respective electronic equipment, i.e. in accordance with its intended use, may also be printed on the respective electronic equipment so that a user can read it directly and attach the electronic equipment to the shelf-board in the correct orientation or alignment. Therefore, the intended orientation of the electronic equipment may also be determined by how it is intended to be attached, for example, by hanging it on cords or similar, or how it is intended to be placed on a table or other object.

[0025] The term electronic equipment may include, but is not limited to, the following devices:

[0026] - an electronic shelf label,

[0027] - an electronic video shelf rail,

[0028] - an electronic temperature sensor,

[0029] - an electronic humidity sensor,

[0030] - an electronic balance

[0031] - an electronic tactile interaction device,

[0032] - an electronic proximity detector device,

[0033] - an electronic shelf rail.

[0034] The electronic equipment typically comprises a housing. The housing delimits an interior space that host all the components (mechanical components and / or electronical components like a printed circuit board, antenna (s) , battery, sensor, etc.) that are necessary to provide the respective functionality. The housing contains, in particular within the internal space, the electronics of the first device. The electronics also feature an antenna configuration which comprises the at least two antennas. The electronics is designed to communicate with other devices, in particular for radio interaction with the second device. The electronics is also configured to control internal processing sequences or functions. This configuration can be implemented in hardware and / or software. The rear side if the housing may realize the mounting device or may be used to attach the mounting device to it. TP0555 7

[0035] Beside of singe- function embodiments that are listed above , the electronic equipment may also contain combined functionalities of the listed devices . The functionalities o f the electronic equipment are used in the management of the products .

[0036] The electronic equipment is typically operated in an infrastructure that comprises as the controlling instance a computer, a server, or a computing center where a software application is executed that utili zes the various functionalities of the electronic equipment for various logistics or product management processes . The infrastructure further comprises communication related electronics like radio access points , routers , etc . , which are typically connected to the controlling instance and faci litate the communication with the distributed electronical equipment .

[0037] As mentioned at the outset , the at least two antennas of the f irst device are used to estimate a spatial property of the first device . The spatial properties of the first device may, for example , include a (potential ) presence of another device and / or a distance estimated from the first device and / or a direction estimated from the first device . In particular, these estimates may be made with respect or in relation, respectively, to a second device . The spatial property then relates to a presence indication that indicates or describes , respectively, the presence of another ( radio ) device and / or a distance indication that indicates or describes , respectively, the ( relative ) distance between the first and second ( radio ) devices and / or a directional indication that indicates or describes , respectively, the ( relative ) direction from the first device to the second device or vice versa or in other words the ( relative ) angular situation between the two devices . In particular, the directional indication may describe the direction from TP0555 8 which a radio signal was transmitted or from which a radio signal was received .

[0038] The mere fact that there is more than one antenna available for detecting the spatial characteristics of the first device , which usually only provides ambiguous information regarding distance , means that this limited characteri zation capability is now expanded to include direction finding using only the first device . It has proven to be extremely advantageous that the first devices , which are intended for the retail or logistics sector, usually have a very speci fic geometry, which naturally also influences the geometric arrangement of at least two antennas , which in turn results in advantageous aspects with regard to signal propagation and ultimately the signal processing to be performed at the receiver . This special geometry is primarily based on the fact that the first device has a predominantly dominant extension in terms of area and that its depth is signi ficantly smaller than its width and height is . This means that the two antennas are essentially, or in other words , with good approximation, be located in the plane spanned by the width and height .

[0039] Focusing now to the speci fic arrangement of the at least two antennas of the first device , whose relative position to each other is oriented towards the (universally valid) hori zontal direction in space , the ef fect is that the fundamentally three-dimensional problem of determining the spatial properties of the first device can be reduced to an estimation in two dimensions . This provides suf ficient accuracy for the intended application of the invention with regard to the parameters to be obtained . Instead of a description of the spatial properties of the first device in the form of , for example , three orthogonal or three Cartesian coordinates or spherical coordinates , a description in two Cartesian coordinates or in polar coordinates can be used . The reduction in accuracy that TP0555 9 may accompany thi s is acceptable for the discussed applications in logistics or retail .

[0040] This reduction of the spatial property to a two- dimensional description ( a distance from a point in space that is located within the first device or even defined by the position of the first device itsel f and a direction relative to the hori zontal direction along which the at least two antennas are arranged at a distance from each other ) ultimately leads to a view in a plane spanned by the estimated variables or to a proj ection onto a hori zontal plane , for example , depending on which view is preferred .

[0041] This reduction of the spatial property to a two- dimensional description also means that the large number of antennas usually required for known AoA detectors and the computing power and associated energy consumption required for processing and evaluating the antenna signals are no longer necessary, and such an implementation can therefore be dispensed with . Consequently, the estimation of the spatial properties of the first device is now also available for low-power or ultra-low-power devices , which are powered by batteries , for example , and whose mode of operation is designed for the longest possible battery li fe . This satis fies a long-standing need for the estimation of the spatial property with manageable and therefore market-acceptable ef fort .

[0042] The second device that can be used in the context of the invention can, for example , be a mobile device , a tablet computer , etc . that is moved around the premises of the retailer or logistics company during operation and used there for a wide variety of purposes .

[0043] The second device may be freely movable , for example by a person, or movable together with a further movable device to which it is attached, for example a shopping cart or a cargo sled or a pallet j ack or a TP0555 10 forkli ft or the l ike . The second device may be permanently operated to send out or to receive the radio signal for the estimation of the spatial property or it may be computeri zed controlled, for example via the existing radio communication infrastructure , to send out its radio signal or to receive the radio signal for the estimation of the spatial property only during certain periods of interest , which may be of advantage to reduce radio channel occupation and / or power consumption .

[0044] This second device is not usually subj ect to the strict low energy consumption requirements mentioned in relation to the f irst device . Even i f the battery charge is depleted, it can essentially be taken to a charging station or have its battery replaced at any time . This option is not usually available for the first device , as it is operated in a fixed location within the room .

[0045] A housing of the second device contains , in particular within an internal space of the housing, the electronics of the second device . The electronics also feature an antenna configuration, which may comprise at least two antennas similar to the configuration of the first device , but not obligators . Therefore , also only one antenna may by reali zed . The electronics is designed to communicate with other devices , in particular for radio interaction with the first device . The electronics i s also configured to control internal processing sequences or functions . This configuration can be implemented in hardware and / or software . The antenna configuration ( one or more antennas and a transceiver arranged to utility the antenna ( s ) ) is used for transmitting and / or receiving radio signals for the purpose of the invention . This enables the second device to cooperate with the first device via radio technology in order to estimate the spatial property of the first device . TP0555 11

[0046] Usually, the second device will not be located in a horizontal plane in which - at least essentially - the at least two antennas of the first device are located. This is actually insignificant and corresponds to reality, in which the second device is located at a more or less arbitrary height in the sales room or storage room and / or is moved there. Usually, the possible height range in which the second device can be located is determined, for example, by the object to which the second device is attached (e.g. shopping trolley, load sled, driving module of a forklift truck, etc., which is also an area of approximately 50 cm to approximately 2 meters above the floor) or by the person carrying the second device (e.g. between hip height and chest height up to shoulder height of an adult, i.e. approximately 70 cm and 1.9 meters above the floor) , and is therefore known in advance in terms of range.

[0047] The fact that the first device is mounted at a different height above the floor in the room merely contributes to a distortion of the estimation of the absolute distance, which is negligible, however, because when comparing the estimation of at least two first devices, the information 'closer to one first device than closer to the other first device' is often sufficient as an estimation for the distance indication .

[0048] This situation is similar with regard to the presence of the second device within the radio reception range and / or transmission range of the first device. When comparing the estimates of at least two first devices, it is often sufficient to know that the second device is present within the radio range of at least two first devices or is present in only one of at least two radio ranges. This estimate is therefore based on a group of first devices or a subgroup of this group, down to a single element of this group. TP0555 12

[0049] The estimation is similar with regard to the estimation of the directional indication . It is often suf ficient to generate an estimation indicating that the second device is located more to the left of the first device than to the right . This estimation can also be generated for a group of the first devices or a subgroup of this group, down to a single element of this group .

[0050] These three categories of estimation (presence , distance and direction) can also be combined with each other to obtain a set of estimates or to veri fy one category of estimation with another category of estimation . The gradual use of the categories also ensures energy-saving operation, especially for battery-powered devices . For example , a statement about presence can be generated first . Only when presence has been veri fied with certainty ( e . g . multiple detections ) is a statement about distance subsequently generated . Only when the distance falls below a threshold value necessary for the reliable generation of a statement regarding direction is a statement about direction subsequently generated . This step-by-step approach takes into account the fact that each step of the estimation is associated with a certain amount of energy consumption and that this energy consumption should therefore only occur when the respective step can be carried out ef ficiently in order to arrive at a reliable estimation of the respective spatial property .

[0051] As the group of f irst devices , first devices located adj acent to each other may be used preferentially . These devices are also preferably located at a hori zontal distance from each other . This makes it possible , in particular, to carry out the estimates of the aforementioned spatial property in shel f-like installation structures of the respective sales room or storage room, because the first devices arranged in this way are positioned according to these TP0555 13 shel f-like facil ity structures , where their respective positions are generally known through previous measures , such as registration or binding to the respective product stored on the shel f , or simply position determination .

[0052] Further particularly advantageous embodiments and extensions of the invention arise from the dependent claims and the following description .

[0053] The first device according to the invention may be any of the afore-mentioned electronic equipment .

[0054] However, preferred the first device may reali ze an electronic shel f label or a rail controller of an electronic shel f rail , or an electronic video shel f rail . The rail controller is configured to control a number of electronic shel f labels , which are electrically connected to the rail controller and installed at the shel f rail that is controlled or driven, respectively, by the electronic shel f controller . These embodiments of the first device are particularly advantageous for the invention in question because they usually account for the largest proportion of the electronic equipment installed on the premises ( sales or storage room) of the retailer or logistics company and are also used there in suf ficient density and comprehensive distribution, which contributes to essentially full-area availability within the respective premise for the purpose of the invention .

[0055] Electronic shel f labels , in short ESLs , are basically known . They typically comprise low power electronics for displaying product and / or price related information typically in a static fashion . For this purpose , ESLs typically comprise for example an electrophoretic display or "e-paper" termed display, respectively, which requires hardly any or no power to display static information The front of the display is visible through an opening in the housing . The electronics also facilitates radio-based or cable-based TP0555 14 communication with a controlling instance that defines the content to be displayed.

[0056] The electronic shelf rail is a device as described for example in the published international patent placation with application number PCT / EP2021 / 055916 or PCT / EP2021 / 055914 , which are incorporated by reference herein. The electronic shelf rail basically realized a bus-system that extends along the fort edge of a shelfboard along the horizontal direction for a horizontal distance that is much longer than a single ESL may cover. ESLs with a cable-based communication embodiment can mechanically couple to the electronic shelf rail and thereby electrically contact wires of the bus system. The rail controller (in German termed "Versogungseinrichtung" in the two mentioned international patent applications) , in particular its electronics, is configured to supply the ELS attached to the electronic shelf rail with electrical power. The electronics also facilitates to supply the ESLs with data via the bus system. The electronics also facilitates radio-based or cable-based communication with the controlling instance that defines the content to be displayed and thereby acts as a gateway to the controlling instance.

[0057] The video shelf rail is a device as described for example in the published international patent applications with application numbers PCT / EP2017 / 078844, PCT / EP2017 / 078845, or PCT / EP2017 / 078846, which are incorporated by reference herein. It is basically configured to play back a video on a video screen that extends in horizontal direction along the front edge of a shelf-board along a longer section of the shelf-board or even along the entire length of the shelf-board. The video shelf rail also comprises electronics that is typically cable-based powered. The electronics also facilitates radio-based TP0555 15 or cable-based communication with the controlling instance that def ines the content to be displayed .

[0058] According to a particular aspect of the invention, the first device comprises exactly two antennas . Since the first device is preferably attached to a shel f board, the orientation of which in the room is usually hori zontally, as discussed at the outset , the implementation of the first device with only two antennas has proven to be extremely advantageous . This allows the estimation of the spatial property with suf ficient accuracy to be achieved with minimal technical ef fort . Since the estimation of the spatial property of the first device involves approximate location within shel f aisles , along which the first devices are attached to the shelves flanking these aisles , better results can be achieved with the first devices configured in this way than would be the case i f access points were used for this purpose , which are usually only sporadically mounted on the ceiling of the respective room and are therefore exposed to adverse radio-technical ef fects such as shadowing and multiple reflections , multi-path signal propagation, etc .

[0059] At the same time , it is advantageous to dispense with the mass , decentrali zed and expensive use of angel of arrival or angel of departure hardware . Instead, the first devices are used as mass-produced hardware that is already available typically throughout the entire af fected room . These devices are already distributed throughout the room, but are relatively inexpensive hardware that can be used to generate an estimate of the angle of arrival or angle of departure of a radio signal , even i f these statements are only estimates because the neces sary hardware , in particular the number of antennas , is reduced to the absolute minimum .

[0060] As discussed, the question of absolute height in the room is not important . Rather, this factor is of secondary importance or even superfluous . Therefore , TP0555 16 the number of antennas can even be reduced to two antennas positioned at a hori zontal distance from each other, which allows the generation of the presence indication, the distance indication and / or the directional indication - all being represented by spatial property data - with suf ficient accuracy .

[0061] Ultimately, this allows an approximate statement to be made about the position within a corridor ( shel f aisle ) , which - based on the position of the first device , which is generally known in the system - can also be reduced to an approximate indication of a direction from the first device towards the second device or from the second device towards the first device

[0062] With regard to the implementation of at least two antennas , it may be envisaged that these can, for example , also be attached to the housing of the first device or integrated into the housing or housing wall . However, this sometimes requires complex cabling with the electronics located inside the housing . Therefore , it has proven to be most advantageous that the first device comprises a printed circuit board, which holds the at least two antennas , preferably comprises the at least two antennas reali zed as printed circuit board antennas . This means that the two antennas are preferably mounted directly on the printed circuit board or, even better, are already present on the printed circuit board as printed antennas .

[0063] This ensures , on the one hand, that the antennas are housed within the enclosure in the best possible way and, on the other hand, that their position and radio characteristics can be planned and implemented with the greatest possible accuracy, especially in the case of printed antennas . Furthermore , printed antennas have the advantage that they are located exactly in the plane of the printed circuit board and, since this printed circuit board is usually aligned parallel to TP0555 17 the front edge of the shel f board, this parallel alignment also applies to the antennas . Their transmission and reception characteristics are therefore identically influenced by the shel f board, making them negligible .

[0064] According to a particular embodiment of the invention, the first device comprises at least one integrated circuit connected to a pair of the at least two antennas and the integrated circuit is configured to utili ze the two antennas . This utili zation includes the ability to receive and transmit radio signals independently via both antennas .

[0065] This measure also contributes signi ficantly to the compact and cost-ef ficient implementation of the invention . In principle , the existing electronics , in particular the part of the electronics intended for radio signal processing, could use at least two antennas . The use of the two antennas could therefore be implemented in a software-controlled manner with little ef fort by switching ( time multiplexing) between the two antennas with a single transceiver . However, in order to ensure e f ficient use of these at least two antennas , the use of a specially designed integrated circuit , in short IC, has proven to be extremely advantageous .

[0066] An IC that can use exactly two antennas is particularly preferred . This favors the reali zation of the previously identi fied preferred design with exactly two antennas . At the same time , the other options with four or even six antennas remain available with manageable ef fort , as only two or three of these ICs would need to be implemented . Since this IC has full transceiver functionality, it can be connected to or integrated into the rest of the electronics in the conventional manner .

[0067] The electronics o f the first device , in particular the IC, as well as the at least two antennas used, in TP0555 18 particular the pairs of antennas connected to the IC, are therefore des igned to transmit and / or receive radio signals that are intended or suitable for estimating the spatial property or environment , respectively, of the first device . This may relate to a distance and / or a direction that can be derived from a radio signal . The estimation of the direction may be a direction from which a radio signal was received or in which a radio signal was transmitted .

[0068] This estimation can be performed on a device other than the first device , on the first device or in cooperation between the devices . This estimation can be performed by radio signal processing on a device other than the first device , on the first device , or in cooperation between the devices .

[0069] According to a further aspect of the invention the first device has a first dimension defining an extension of an outer dimension of the first device , and wherein the outer most antennas of the at least two antennas are arranged along the first dimension with a distance between them of at least 20% , preferably at least 50 % , particularly preferably at least 75 % , most preferably at least 80 % , of the first dimension of the first device . The first dimension is measured analogously to the hori zontal distance between the at least two antennas . The first dimension can also be referred to as the width of the first device . In accordance with the usual conventions , the first device also has a depth ( second dimension) and a height ( third dimension) . In order to obtain signal parameters that are easily distinguishable from one another or easily comparable with one another (both when receiving on the side of the first device or when receiving on the side of the second device ) , it has proven particularly advantageous to make the hori zontal distance between the antennas as large as possible thus making optimum use of the available space in the housing or on the TP0555 19 printed circuit board . Thus , the percentages essentially describe a locali zation within the housing of the first device . This also ensures that , because of the limit the interior space of the first device by the housing of the first device , there remains suf ficient space for mechanical and electrical connections , such as those required for j oining housing parts or connecting a screen to a printed circuit board .

[0070] Similar considerations to those made in the preceding paragraph in connection with the spatial availability for the hori zontally spaced installation of at least two antennas within the housing can also be made for the installation or integration with the printed circuit board carrying the electronics of the first device . According to this aspect of the invention, the first device comprises a printed circuit board, wherein the printed circuit board has a first dimension of the printed circuit board defining an extension of an outer dimension of the printed circuit board, and wherein the outer most antennas of the at least two antennas are arranged along the first dimension of the printed circuit board with a distance between them of at least 20% , preferably at least 50 % , particularly preferably at least 75 % , most preferably at least 80 % , of the first dimension of the circuit board . The first dimension is measured analogously to the hori zontal di stance between the at least two antennas . The first dimension of the circuit board can also be referred to as the width of the printed circuit board that is typically smaller than the width of the first device . The depth of a printed circuit board is in the typical range known to the person skilled in the art , while the height of the printed circuit board will be less than the height of the first device .

[0071] In addition to the requirement that there should be a hori zontal distance between the at least two antennas , the at least two antennas may be arranged at TP0555 20 different heights. This means that, measured in the direction of the height (of the device or the printed circuit board) , the at least two antennas may be located at different positions, i.e. there may be a so- called 'height difference' or height offset between them.

[0072] The same applies to the positioning of the at least two antennas along the depth of the first device. Along this dimension, there may be a depth offset between the at least two antennas in order to make optimum use of the space available within the housing of the first device. As far as positioning on the printed circuit board is concerned, especially when using printed antennas, this depth offset is limited by the thickness of the printed circuit board. However, if a multilayer printed circuit board is used, the depth offset for printed antennas can also be smaller.

[0073] The height offset and / or depth offset may facilitate the optimal use of available space within the housing or available area on the printed circuit board for positioning the at least two antennas.

[0074] This allows available free space or open areas to be used for the respective additional number of antennas without having to make any significant changes to the existing use of space and / or area in the first device. If, for example, several antenna pairs are used in the first device, the respective offset (horizontal offset, height offset, depth offset) can be used to create slightly different positions for the antennas. This allows the initial result of the spatial property estimation generated with one of the antenna pairs to be checked or validated with another antenna pair during operation.

[0075] According to a preferred embodiment of the invention the first device comprises a battery configuration for powering its electronics, which in particular is low power consumption optimized TP0555 21 electronics . I t has therefore proven advantageous to operate the first device according to an operating scheme in which it is operated as often as possible in an energy-saving idle state and is only active in terms of radio technology when this is actually necessary . Accordingly, the preferred operating mode is one in which the first device has to remain in a receiving state as rarely as possible and, above all , only for as short a time as possible in order to receive radio signals for the purpose of estimating the spatial property . I f the first device had to remain in a receiving state for longer periods of time , the energy consumption that would occur would exceed the energy consumption that would occur during the transmission of radio signals for the purposes of the invention during a relatively short time interval , which is usual .

[0076] Irrespective of the aforementioned preferred operating scheme , the first device is configured to send a transmit radio signal and to receive a response radio signal via each of the at least two antennas . With regard to the method, this means that the method comprises the following steps , namely : sending a transmit radio signal by the first device or the group of first devices and receiving a response radio signal from the second device at the first device . This set of features provides that the first device , in particular its electronics , is configured to estimate the spatial property of the first device using Phase-Based Ranging and / or Round-Trip Time , both methods are techniques know to the person skilled in the art , in particular being familiar with Bluetooth ® . These techniques are typically used for distance estimation . This form of embodiment makes it possible for the first time to use low energy consuming devices like electronic display labels , in particular electronic shel f labels (ESLs ) , for the purpose of TP0555 22 estimating the spatial properties in retail or logistics .

[0077] Hence, both, the first device and the second device are enabled for estimating the special property using Phase-Based Ranging and / or Round-Trip Time measurement .

[0078] Such devices are small and positioned in large numbers at relatively regular intervals in the respective storage rooms.

[0079] In addition, the special antenna configuration of at least two antennas in the first device also enables direction finding with the least possible technical effort in an infrastructure consisting of low-power devices, namely the ESLs or other aforementioned embodiments of the first device. The special antenna configuration of the ESL (or the other mentioned embodiments of the first device) allows, in particular, the implementation of an Angle of Departure method. "In the Angle of Departure (AoD) method, the transmitting device has an antenna array. The receiving device has a single antenna (or uses a single antenna if multiple antennas are available) but possesses details of the antenna array in the remote, transmitting device. This enables it to make similar calculations from phase measurements made at its single antenna" , which is explained in the document "Bluetooth® Channel Sounding", revision date 9 July 2024, author Martin Woolley, Bluetooth SIG. Advantageously, in this AoD method radio signals are transmitted from the transmitting device (first device, ESL, etc.) via at least two antennas with their specific positioning relative to each other, which are then processed or evaluated with the corresponding processing effort and associated energy requirement on the side of the receiving device (second device) . This approach significantly extends the battery life of the low-power device (ESL, etc. ) and is therefore preferable to the TP0555 23 reverse configuration that would be present in the case of the Angle of Arrival (AoA) method . The energy savings per first device may be small , but in an ecosystem where tens of thousands of such low-power devices are installed in a single warehouse or sales room, even these small savings make a signi ficant contribution to extending maintenance intervals and thus to the overall economic situation of the system .

[0080] Further to this , since Bluetooth ® technology now also supports ESLs technologically, the invention now enables the use o f ESLs for the purpose of the invention . This also enables the use of such ESLs for channel sounding purposes for the first time , which enhances the accuracy of the estimation of the spatial property of the f irst device ( s ) signi ficantly .

[0081] Channel sounding is not limited to Bluetooth ® . However, in the present context , reference should be made to the mentioned document 'Bluetooth® Channel Sounding' . The present invention makes this technology available for the first time in retail or logistics by means of ESLs and similar low-energy devices ( see the electronic equipment ) with relatively inexpensive electronic components , whereby the first devices are positioned as frequently and evenly as possible so to create a grid of first devices for the purpose of the invention . The basis for this applicability is the special geographical arrangement of the antennas in the first device , so that the estimation of the spatial property of the f irst device ( the presence indication, the distance indication, and / or the directional indication) is made possible with minimal hardware expenditure but with enhanced accuracy caused by multi antennas at one or both involved devices . Hence the first device is advantageously configured (programmed) to perform channel sounding, in particular Bluetooth channel sounding in accordance with the technology TP0555 24 described in the above-mentioned document 'Bluetooth® Channel Sounding' or any later version thereof .

[0082] In addition to the aforementioned feature or complementary to this feature , the first device is configured to derive a received signal strength indicator, commonly abbreviated as RSS I , for a radio signal that was received by the at least two antennas and / or to transmit a radio signals with at least one of the at least two antennas , so that the received signal strength indicator is derivable when received, in particular at the second device .

[0083] The "Received Signal Strength Indicator" may be used because it i s common that the receiving circuit of the respective radio device ( the first device and / or the second device ) computes this value automatically . The RSS I represents the power level of signals received by a wireless device . It indicates the strength of the signal and is expressed in dBm ( decibels relative to one milliwatt ) , for example in the range of 0 dBm to - 120 dBm . A higher RSS I value generally corresponds to a stronger signal . As an example , an RSS I of less than - 90 dBm indicates an extremely weak signal , in particular at the edge of receivability of the signal , while an RSS I of more than -30 dBm indicates a very strong signal coming from a sending device in closest proximity .

[0084] Deriving an RSS I based on a received radio signal is therefore generally known to the person skilled in the art and is provided by the hardware of the transceiver used . By using at least two antennas , a signi ficant improvement in the estimation of the spatial property of the first device can be achieved compared to using only one antenna . With at least two antennas , a radio signal can be received and processed essentially simultaneously . Advantageously the transceiver is configured to derive the RSS I value for each of the generate two signals . TP0555 25

[0085] I f , on the other hand, the first device is to be used to transmit a radio signal that is to be evaluated regarding the RSS I on the side of another device , namely the second device , di f ferent scenarios may apply . For example , only one of at least two antennas may be used to transmit the radio signal . I f , on the other hand, the two antennas are used to transmit individual signal s , they are advantageously used in time division multiplex mode so that the radio signals can be transmitted without interfering with each other .

[0086] According to a further aspect of the invention, the first device is configured to operate in a first mode , in which a first estimation of the special property is made base on the derived received signal strength indicator, and a second mode , in which a second estimation of the spatial property is made by Phase-Based Ranging and / or Round-Trip Time measurement , wherein the first device is adapted to switch between the first mode and the second mode .

[0087] This embodiment enables the device to vary its operating behavior when assessing the spatial environment , depending on the situation resulting from the requirements defined by the controlling instance or software , or from the respective radio parameters . For example , the first estimate can be understood as a rough estimate . In contrast , the second estimate can be understood as a much more refined or improved estimate compared to the f irst estimate .

[0088] As discussed, the transition from the first estimate to the second can be controlled by the controlling instance or software . On the other hand, the device itsel f can also be configured or programmed, respectively, to switch from the first mode to the second mode or vice versa .

[0089] Regardless of which implementation is chosen to control the trans ition from the first mode to the second mode or vice versa, a criterion can be applied TP0555 26 as a basis for decision-making . This could be , for example :

[0090] - the occurrence of a threshold value of the RSS I or

[0091] - the occurrence of a frequency of an RSS I value , in particular a predefined value of the frequency, possibly also combined with a predefined RSS I value , or

[0092] - the occurrence of an RSS I value belonging to a radio signal from a speci fic (predefined) device .

[0093] Therefore , in terms of the method it is advantageously provided that the method comprises the following steps for estimating the spatial property, namely : operating a first mode , in which a first estimation of the special parameter is made base on a derived received signal strength indicator, and operating a second mode , in which a second estimation of the spatial parameter is made by Phase-Based Ranging and / or Round-Trip Time measurement , and switching from the first mode to the second mode i f the ful fillment of a criteria is detected .

[0094] According to a particular embodiment , which is based on the principle of implementation that is as unproblematic as possible , the first device is adapted to switch between the first mode and the second mode when a certain value for the received signal strength indicator is reached . This can be done by determining this RSS I value directly in the first device and then using it as the basis for the decision to switch from the first mode to the second mode . However, it is also possible to determine this RSS I value in the second device and then communicate it to the first device , where the decision is made based on this value , or, alternatively, based on the RSS I value determined in the second device , the first device is instructed by the second device to change its operating state from the first mode to the second mode .

[0095] In connection with the second device , it should also be mentioned that the second device can also be TP0555 27 advantageously configured for phase-based ranging and / or round-trip time signal processing . It is also advantageously configured to generate the RSS I value for a received radio signal and to process it in analogy to the processing capabilities of the first device . Furthermore , it is configured for channel sounding with the first device . The second device may also have two modes , as previously described in connection with the first device , between which it can switch autonomous ly or between which it is designed to switch in a controlled manner .

[0096] In addition, the second device may also have a user interface , such as a screen or audio output device , which it can use to instruct a user of the second device regarding a direction or route to take , whereby the direction or route is derived from a predefined list o f location-based activities that must be completed in that order . The basis for navigation in the respective storage room is provided by the first devices , which are fixed in position and known in terms of location, and with the help of which the respective presence indicator, distance indicator or direction indicator is generated by radio interaction between the second device and one or more first devices . Furthermore , it may be provided that the second device has a machine interface with the aid of which an autonomously drivable device ( e . g . an electrically motori zed shopping trolley, a load sledge or a forkli ft truck, etc . ) can be controlled to follow a (predefined) rout and / or to perform speci fied location-based activities . The navigation instructions required for this are determined in the same way as described above . Furthermore , with regard to the implementation of the first mode in a group of first devices , the first mode my comprise the following steps : computeri zed defining at least two first devices for receiving a radio signal that is being sent out from a second device , TP0555 28 wherein the at least two first devices are located at di f ferent known positions , in particular within a room, in particular within the sales room or storage room, and the second device is movable , and computeri zed estimating the direction from which the radio signal was received based on representations - in particular an RSS I value - of the reception signal strength delivered by each of the at least two first devices as a result of receiving the radio signal at both of the at least two first devices , or based on a representation - in particular an RSS I value - of the reception signal strength delivered by a first of the at least two first devices and either a lack of another representation - in particular an RSS I value - from a second of the at least two first devices ) as a result of non-reception of the radio signal or a message from the second of the at least two first devices , which message indicates the non-reception of the radio signal

[0097] ( S ) at the second of the at least two first devices . These procedural steps extend the first mode to include the interaction of several first devices . The representation of the reception signal strength can be evaluated either through interaction between the participating first devices or by the controlling instance or software , so that it is possible to switch to the second mode depending on the situation . This change is carried out on only one of the first devices involved, for example , the one with the best or most favorable reception situation, or, i f appropriate , because the radio signal is received by several first devices , for this group of first devices .

[0098] In the operational management of a supermarket , the invention presented can be used, for example , to guide a so-cal led store picker . The store picker carries the second device in the form of a smartphone .

[0099] The supermarket ' s server transmits a customer ' s shopping list to the smartphone , and the store picker TP0555 29 must collect the products listed on the list in the store , which is referred to below as his order, and then make them available to the customer or hand them over to him .

[0100] The server has access to a data structure that is stored, for example , in a database and which is used to store the supermarket ' s products , their location in the supermarket and also the ESLs assigned to the products , which form the first devices . It is assumed that the location of the products essentially corresponds to the location of the ESLs . The relevant ESLs are therefore fixed at the front edges of the shelves on which the products are stored, corresponding to the respective position of the products .

[0101] The store picker begins processing his order at a known starting point in the sales area, and when he starts processing the order, the Bluetooth ® transceiver of hi s smartphone is activated to receive a radio signal . Similarly, the nearest ESL is instructed via the supermarket ' s communication infrastructure to activate its Bluetooth ® transceiver and transmit its radio signal . It should be noted in this context that the radio signal has a unique code , which the smartphone has al so been informed of in advance in order to identi fy the relevant radio signal . Such a radio signal is typically termed radio beacon signal . As soon as the radio signal is received with suf ficient quality, e . g . with a certain RSS I value , channel sounding is used between the two devices so that the position of the second device relative to the first device can be estimated with good accuracy . In channel sounding, for example , the second device can take on the role of the initiator and the ESL the role of the reflector, because the initiator usually has to perform the computational ly intensive operations , which are also reflected in energy consumption, which should be kept as low as possible in battery-powered ESLs . TP0555 30

[0102] The smartphone ' s Bluetooth ® controller transmits the data obtained in this way to the Store Picker software application running on the smartphone , where the distance between the two devices is determined and navigation instructions are derived from this and communicated to the Store Picker via the smartphone ' s user interface .

[0103] In addition, the at least two antennas of the ESL are used to determine the angle of departure by sending individual radio signals to the smartphone that receives the radio signals , which is also more energyef ficient for the operation of the ESLs . The smartphone ' s Bluetooth ® controller transmits the data obtained in this way to the store picker software application running on the smartphone , where navigation instructions are derived from it and communicated to the store picker via the smartphone ' s user interface .

[0104] The determination of the distance and the direction from which the radio signal originates can take place at di f ferent times , for example . The two devices can there fore coordinate with each other to determine the time period during which their transceivers are used to determine the current distance or the direction from which the radio signal originates . However, this can also be done according to a predefined protocol .

[0105] The distance between the two devices , which is automatically determined in this way by the second device , as well as the direction from which the radio signal originates , or the change in these two variables or parameters over time , can then be transmitted to the server, which ensures that at least one first device in the vicinity of the second device is always active for the described radio-based navigation support . The server can therefore initiate the trans fer from one ESL to another via the ESLs ' communication infrastructure . It may also be provided that the first device involved TP0555 31 in radio communication with the second device informs the server on its own initiative when a predefined RSS I or a temporal trend of the RSS I occurs , so that the server activates another ESL that is potentially better positioned for the purposes of navigation support .

[0106] With the help of the navigation information, the store picker is guided according to the available shopping list on a route with the shortest distance from one product to be collected to the next product to be collected . Thi s procedure ensures that the store picker always performs its task on the optimal route , i . e . the route predefined by the server, without giving it the freedom to deviate from this route on its own initiative . This ensures optimal ef ficiency in the execution of its task .

[0107] The use of the measures described has proven to be particularly advantageous in that , for example , functions can be triggered in the af fected ESL that depend on the direction and / or distance of the second device . For example , it is possible to determine with great accuracy whether the second device is already located within a predetermined area near the ESL . I f the second device is located within this predetermined area, the ESL can display di f ferent information ( information with relevance for the store picker or information with relevance for the customer or information related to a promotion or information related to a product , as the case may be ) than i f the second device were further away or located in a direction from which it can be assumed that the user of the second device cannot read the screen optimally . In this context , it should also be mentioned that the ESL can, for example , have a light-emitting device such as an LED that is only activated when the second device is located within a certain distance and / or in a certain direction . I f the second device moves out of this area again, the light emission is switched of f again . These TP0555 32 measures can be used to assist a customer who is searching for something or a store picker at work . Furthermore , these measures optimi ze energy consumption in the ESL, because the light emission operation of the LED should generally be avoided as much as possible in order to conserve battery li fe .

[0108] It may also be provided that , if a user interface is present on the first device , this user interface is only activated under the specified conditions regarding distance and / or direction .

[0109] In particular , when supporting or monitoring the activities of the store picker with the help of the aforementioned measures , it can be determined that the store picker is in the immediate vicinity of a location where a subtask is to be completed with regard to a product located there . Once this situation has been automatically determined using the expected measures , the system ( the control l ing instance or in the second device ) can register that the subtask is assumed to have been completed . The occurrence of this assumption may also depend on how long the store picker has been in the relevant vicinity of the product in question .

[0110] With regard to radio communication between the first and second devices , it should be noted that the same radio protocol and / or frequency band can be used as that used in the infrastructure of the first device ( e . g . as mentioned, Bluetooth® in the 2 . 4 GHz frequency band) . In contrast , a di f ferent radio protocol and / or frequency band can be used for radio communication between the first and second devices , for example to ensure that this radio communication does not cause problems with the radio communication in the infrastructure of the first device .

[0111] The presence of two antennas in the ESL also allows these two antennas to be used for di f ferent communication tas ks . For example , one antenna can be used to communicate with the ESL infrastructure ( e . g . , TP0555 33 with an access point) , while the second antenna is used to communicate with the second device.

[0112] The measures discussed also make it possible to reliably determine whether the second device is located directly in front of a shelf, in particular a product positioned there that is marked with a specific ESL, or whether it is located next to it, i.e. to the left or right of it. Furthermore, the measures described also make it easy to verify whether the second device is actually located in the relevant shelf aisle in front of the relevant product or in an adjacent shelf aisle. To verify that the second device is located in the correct shelf aisle in front of a specific first device (e.g. ESL, etc.) , another first device (e.g. ESL, etc.) can be activated for a short time and establish radio contact with the second device, whereby the other first device is, for example, positioned essentially opposite the aforementioned specific ESL or at least positioned in its vicinity on the other side of the aisle. The signal parameters received and evaluated (e.g. RSSI, angle of departure) during these two radio communications (with the specific ESL and with the additional ESL) allow a clear determination that the second device is in the correct aisle or in another aisle. Based on this, the navigation instructions for this correct aisle can be provided to the customer or store picker on the second device. However, if it is determined that the second device is in the wrong aisle, this can be communicated to the user of the second device so that she / he can change to the correct aisle accordingly in order to perform her / his tasks efficiently and quickly.

[0113] Furthermore, the invention discussed can also be used, for example, to employ at least two or more (e.g. three or four) first devices (in particular ESLs) positioned relatively far apart from each other to determine the relative position of the second device. TP0555 34

[0114] However, the at least two first devices are so close to each other that they can both be in radio contact with the second device . In this way, the second device can interact alternately with the respective first device via radio technology and, for example , determine the respective distance or angle of departure , from which a highly precise position determination for the second device is ultimately calculated or created either in the second device itsel f or in the controlling instance . This approach can be particularly advantageous i f , for example , so-called rail controllers are used as the first devices . These are already relatively far apart from each other because the electronic shel f rail they control extends between them . It is also possible that only a single antenna from each of the first devices positioned at a distance from each other i s used to estimate the relative position of the second device . In this application scenario , too , the angle of departure ( relative to the overall configuration of at least two of the first devices ) can be determined and the distance can be calculated using channel sounding .

[0115] In this case , it is particularly preferable to use the antenna of the first device involved that is furthest away from the other first device in order to keep the distance between the antennas as large as possible and thus improve the accuracy of the estimation .

[0116] Finally, it is to mention that electronic devices mentioned in the description of this patent application may be reali zed by the aid of well-known discreet and / or integrated electronics . Provided that interfaces are required the person skilled in the art will be able to select and des ign the appropriate interfacecircuitry to enable data and / or signal communication . Radio communication interfaces , known as transceivers , typically comprise an antenna configurational connected TP0555 35 with well-known transceiver electronics . Programmable devices may comprise a microprocessor and some peripheral electronics . Such programmable devices may also be reali zed by the aid of a microcontroller or an application speci fic intergraded circuit (AS IC ) and the like . Execution o f software routines on such devices provides computer implemented functions that are discussed herein .

[0117] These and other aspects of the invention are obtained from the figures discussed below .

[0118] BRIEF DESCRIPTION OF THE FIGURES

[0119] The invention is explained again hereafter with reference to the attached figures and based on exemplary embodiments , which nevertheless do not limit the scope of the invention . In the di f ferent figures the same components are labelled with identical reference numbers . They show in schematic fashion in :

[0120] Fig . 1 a section of an ESL system with several

[0121] ESLs attached to the front edges of shelve boards ,

[0122] Fig . 2 a block diagram of the ESL with two antennas used in Figure 1 ,

[0123] Fig . 3 examples of the arrangement of the two antennas in the ESLs according to Figure 2 .

[0124] DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0125] Figure 1 visual i zes a section of an electronic display signs system 100 . This section shows a server 1 connected to an access point 3 via a wired network 2 ( local area network) .

[0126] The server 1 is configured or programmed to manage a large number of electronic display signs in a TP0555 36 supermarket, specifically to supply them with display data, which is then used by the electronic display signs attached to various shelves to display the relevant information. The electronic display signs are referred to in technical jargon as electronic shelf labels, or ESLs 4 to 11 for short. The information displayed with their help usually relates to the products positioned corresponding to the ESLs 4 to 11. The server 1 also stores and manages a so-called realogram, which indicates the actual position of the respective product and, consequently, the corresponding ESLs 4 to 11 in the supermarket.

[0127] The access point 3 forms a radio gateway to the ESLs 4 - 11 assigned to it and uses Bluetooth ® for radio communication with the ESLs 4 - 11 assigned to it .

[0128] The ESLs 4 - 11 are attached to a shelf 12, which has a first shelf board 13 and a second shelf board 14. In order to visualize different mounting configurations, it is assumed in the present case that the (in itself flat) first shelf board 13 is oriented substantially in the horizontal plane, which is illustrated by a right angle 15 between the first shelf board 13 and a vertical wall 12A of the shelf 12. In contrast, the (in itself flat) second shelf board 14 is inclined slightly downward, which is illustrated by an angle 16 that is less than 90° between the second shelf board 14 and the vertical wall 12A.

[0129] Regardless of this, a front edge 13A of the first shelf board 13 and a front edge 14A of the second shelf board 14 run along the horizontal direction, which follows the respective x-axis.

[0130] This circumstance is visualized by two Cartesian coordinate systems, each of which has its origin in the front left corner of the respective shelf board 13 and 14 and from which the x-axes run parallel to each other and each run essentially parallel to the floor 200. The TP0555 37 floor 200 is only indicated in part. A foot section 12B of the shelf 12 is placed on it. The z-axis of the coordinate systems is oriented against the gravitational acceleration.

[0131] The ESLs 4 to 7 are attached along the front edge 13A. The ESLs 8 to 11 are attached along the front edge 14A. Their fronts are visible from the right at an angle, indicating that they are oriented toward an aisle in front of shelf 12.

[0132] The Figure 1 also shows a mobile phone or smartphone, respectively, 17 belonging to a person (not shown) being moved along a path 300.

[0133] When operating the system 1, radio signals exchanged between the respective ESL 4-11 and mobile phone 17 are used to generate information regarding the distance to the respective ESL 4-11 and mobile phone 17 or information regarding the direction from which the respective radio signal was received, depending on the task at hand.

[0134] This enables highly accurate navigation support to be provided via the smartphone 17, e.g., for a customer or an employee of the supermarket.

[0135] For example, an initial distance 18 between the ESL 6 and the mobile phone 17 can be determined exclusively by determining the RSSI in the respective entity (ESL 6 or mobile phone 17) or by channel sounding. For this purpose, a single antenna in the ESL 6 can be used, or both antennas can be used, but then with a time delay. The same applies to a second distance 19 to the ESL 7 or a third distance 20 to the ESL 9.

[0136] Such further distance determinations can be used, for example, to verify the reliability of a distance of actual interest (in this case to ESL 6) or to ensure that mobile phone 17 is actually in front of shelf 12 and not behind shelf 12. Also the ESL(s) of another, neighboring shelf can be used for this purpose. TP0555 38

[0137] In addition, based on the fact that ESLs 4 to 11 each have two antennas , it is also possible to determine for mobile phone 17 from which direction the respective radio signals , which were emitted individually by the two antennas , were received .

[0138] This makes it possible to subsequently determine whether the mobile phone 17 is located to the right 22 or to the left 23 of the ESL 6 . This is illustrated with the aid of a central line that is normally aligned with the front of the ESL 6 and from which the directions right 22 and left 23 extend normally to this central line 21 . As discussed in detail in the general description, the absolute height of the mobile phone 17 above the floor 200 is of less importance here , so that two antennas positioned at a hori zontal distance from each other in the ESL 4 to 11 are suf ficient for characteri zing the direction .

[0139] ESLs 4 to 11 , which have exactly two antennas , are particularly preferred, as discussed and visuali zed with the aid of Figures 2 to 3 .

[0140] Figure 2 shows a block diagram of ESL 6 , which is representative of all ESL 4- 11 . ESL 6 has an electrophoretic display 21 that maintains the information displayed even without power consumption . The screen 21 is connected to a microcontroller 22 , which is designed and programmed to control internal data processing, control the screen 21 , and control the radio activities of the ESL 6 . The radio activities primarily include radio communication with the access point in order to receive display data from the server 1 and, i f necessary, also to transmit status messages to the server 1 . Furthermore , the microcontroller 22 is programmed to establish radio interaction with the mobile phone 17 in order to enable the discussed distance and direction determination .

[0141] For these purposes , the ESL 6 also has a transceiver circuit 23 , which is configured for the TP0555 39 operation of two antennas and to which two antennas 24 and 25 are consequently connected . It should be noted in this context that the transceiver circuit 23 shown separately here can also be part of a functional group consisting of microcontroller electronics and transceiver electronics , which is symboli zed by the dashed line encompassing elements 22 and 23 .

[0142] The ESL 6 also has a battery ( configuration) 26 that provides a supply voltage VCC relative to a reference potential for the operation of the electronic components of the ESL 6 .

[0143] Figure 2 already indicates a special arrangement of the two antennas 24 and 25 , namely at a hori zontal distance from each other within the ESL 6 , which is indicated by the coordinate system taken from Figure 1 next to the block diagram, whereby the hori zontal distance 27 is measured along the hori zontal coordinate axis x .

[0144] Figure 3 now shows the ESL 6 with its printed circuit board 28 , which, apart from the screen 21 , which is usually arranged to cover the printed circuit board 28 at the front of the ESL 6 , carries the electronics of the ESL 6 . The ESL 6 has a width Wl , which is referred to as the first dimension of the ESL 6 in the general description, and a height Hl , which is referred to as the third dimension in the general description . Also , the printed circuit board 28 has a width W2 and a height H2 as indicated in the Figure 3 . Both, the width W2 and the Height H2 of the printed circuit board 28 are smaller than the respective dimensions Wl and Hl of the ESL 6 . Both widths Wl and W2 are measured along the x-axis . Both heights Hl and H2 are measured along the z-axis .

[0145] For reasons of clarity, the details of the electronics have been omitted in order to focus on the possible arrangements of the two antennas 24 and 25 . For reasons of simplicity, the transceiver 23 to which TP0555 40 the two antennas 24 and 25 are connected is shown centrally. In order to ensure the horizontal distance 27 between antennas 24 and 25, a wide variety of positions are available on the left and right sides or areas, respectively, of the printed circuit board, as indicated by the multiple positioning of antennas 24 and 25. These positioning areas or options are essentially equivalent, whereby the existence of other electronic components must always be taken into account and sufficient space must of course be provided on the printed circuit board 28.

[0146] The two antennas 24 and 25 are preferably realized as printed antennas, which must be taken into account in the circuit design with regard to the surface area of the respective antennas 24 and 25.

[0147] The pair of antennas 24 and 25 positioned in this way is located in the ESL 4 to 11 attached to the shelf 13 or 14 essentially in a vertical plane spanned by the coordinate axes x and z or slightly inclined out of this vertical plane or pivoted against it, which, however, does not impair functionality because the horizontal distance 27 between the antennas 24 and 25 is maintained.

[0148] It is also mentioned that antennas 24 and 25 can be arranged on the front side of the printed circuit board 28 and / or on the rear side of the printed circuit board 28. Thus, both antennas 24 and 25 can be arranged either on the front side or on the rear side. It may also be provided that one antenna (e.g., the first antenna 24) is arranged on the front side and the other antenna (e.g., the second antenna 25) is arranged on the rear side of the printed circuit board 28, i.e., there is an alternating arrangement with respect to the front side and the rear side.

[0149] The visualization in Figure 3 can also be understood to mean that more than one antenna pair 24 and 25 is provided. For example, two antenna pairs 24 TP0555 41 and 25 or even three antenna pairs 24 and 25 may be provided, ultimately resulting in a configuration in which four antennas 24 and 25 or six antennas 24 and 25 exist .

[0150] All of the antennas 24 and 25 can be connected to a single transceiver 23. However, it is preferable to use a transceiver 23 that uses exactly one pair of antennas 24 and 25. This allows an ESL 6 with two antennas 24 and 25 to be implemented with minimal effort. If more antenna pairs 24 and 25 are necessary or desired, the number of antenna pairs can be increased to two or three by adding an additional transceiver 23 or two additional transceivers 23. With regard to the positioning of the transceiver 23, it should be noted that it does not have to be positioned centrally .

[0151] Since the ESLs 4 - 11 can be available in different sizes (typically in a range from 1.5" to 12.2" (inches) , which indicates the diagonal of the screen) , the space available for the antennas 24 and 25 can be optimally utilized. Small ESLs 4 to 11 can, for example, be equipped with exactly one antenna pair 24 and 25, whereas larger ESLs 4 to 11 have several (for example up to three) antenna pairs 24 and 25 because more space is available on their printed circuit board 28. This allows for easy scalability in terms of the number of antenna pairs 24 and 25, taking into account the available space in ESL 4 - 11.

[0152] Finally, let it be noted once again that the figures described in detail above only involve exemplary embodiments, which the expert can modify in a wide variety of ways without departing from the area of the invention. For the sake of completeness, let it also be stated that use of the indeterminate article "a" or "an" does not mean that the respective features cannot be present multiple times.

Claims

TP0555 42CLAIMS1. A first device (4 - 11) , which is realized as a shelf mountable device, comprising:- at least two antennas (24, 25) for the purpose of estimating a spatial property of the first device (4 - 11) , in particular in relation to a second device (17) , preferably the at least two antennas (24, 25) are arranged in a horizontal distance (27) to each other when the first device (4 - 11) is oriented in accordance with its intended use.

2. The first device (4 - 11) according to claim 1, wherein the first device (4 - 11) realizes an electronic shelf label or a rail controller, which is configured to control a number of electronic shelf labels, which are electrically connected to the rail controller and installed at a shelf rail, or an electronic video shelf rail.

3. The first device (4 - 11) according to claim 2 which comprises exactly two antennas (24, 25) .

4. The first device (4 - 11) according to any of the proceeding claims, wherein the first device (4 - 11) comprises a printed circuit board (28) , which holds the at least two antennas (24, 25) , preferably comprises the at least two antennas (24, 25) realized as printed circuit board antennas.

5. The first device (4 - 11) according to any of the preceding claims, which comprise at least one integrated circuit (23) connected to a pair of the at least two antennas (24, 25) and the integrated circuit (23) is configured to utilize the two antennas (24, 25) .TP0555 436. The first device (4 - 11) according to any of the proceeding claims, wherein- wherein the first device (4 - 11) has a first dimension (Wl) defining an extension of an outer dimension of the first device (4 - 11) , and- wherein the outer most antennas of the at least two antennas are arranged along the first length with a distance between them of at least 20%, preferably at least 50 %, particularly preferably at least 75 %, most preferably at least 80 %, of the first dimension (Wl) of the first device (4 - 11) .

7. The first device (4 - 11) according to any of the proceeding claims, wherein the first device (4 - 11) comprises a printed circuit board (28) ,- wherein the printed circuit board (28) has a first dimension (W2) of the printed circuit board (28) defining an extension of an outer dimension of the printed circuit board (28) , and- wherein the outer most antennas of the at least two antennas (24, 25) are arranged along the first length of the printed circuit board with a distance between them of at least 20%, preferably at least 50 %, particularly preferably at least 75 %, most preferably at least 80 %, of the first dimension of the circuit board (28) .

8. The first device (4 - 11) according to any of the preceding claims, which comprises a battery configuration (26) for powering its electronics (21, 22, 23) , which in particular is a low power consumption optimized electronics.

9. The first device (4 - 11) according to any of the preceding claims, which is configured to send aTP0555 44 transmit radio signal and to receive a response radio signal .

10. The first device (4 - 11) according to any of the preceding claims, which is configured to estimate the spatial property of the first device (4 - 11) using Phase-Based Ranging and / or Round-Trip Time.

11. The first device (4 - 11) according to any of the proceeding claims, wherein the first device (4 - 11) is configured to derive a received signal strength indicator for a radio signal that was received by the at least two antennas (24, 25) and / or to transmit at least two radio signals with at least two of the at least two antennas (24, 25) , so that the received signal strength indicator is derivable when received.

12. The first device (4 - 11) according to claim 10 in combination with claim 11, which is configured to operate in a first mode, in which a first estimation of the special property is made base on the derived received signal strength indicator, and a second mode, in which a second estimation of the spatial property is made by Phase-Based Ranging and / or Round-Trip Time measurement, wherein the first device is adapted to switch between the first mode and the second mode.

13. The first device (4 - 11) according to claim 12, wherein the first device (4 - 11) is adapted to switch between the first mode and the second mode when a certain value for the received signal strength indicator is reached.

14. A second device (17) , which is configured to transmit a radio signal between the first device (4 - 11) according to claim 1 to 14 and the second deviceTP0555 45(17) for the purpose of estimating a spatial property of the first device (4 - 11) .

15. A system comprising at least one first device (4 - 11) according to any of the preceding claims 1 to 13 and a second device (17) according to claim 14.

16. A method for estimating a spatial property of a first device (4 - 11) , wherein the first device (4 - 11) or a group of first devices (4- 11) comprises at least two antennas. (24, 25) for the purpose of estimating a spatial property of the first device (4 - 11) , in particular in relation to a second device (17) , preferably the at least two antennas (24, 25) are arranged in a horizontal distance (27) to each other when the first device (4 - 11) is oriented in its intended direction, wherein the method comprises the following step:- transmitting of a radio signal between the first device (4 - 11) or the group of first devices (4 - 11) and a second device (17) for the purpose of estimating a spatial property of the first device (4 - 11) .

17. The method according to claim 16, wherein the method comprises sending a transmit radio signal by the first device (4 - 11) or the group of first devices (4 - 11) and receiving a response radio signal from the second device (17) at the first device (4 - 11) .

18. The method according to any of the preceding claims 16 to 17, wherein estimating the special property uses Phase-Based Ranging and / or Round-Trip Time measurement.

19. The method according to any of the preceding claims 16 to 18, wherein the method comprises the following steps for estimating the spatial property:TP0555 46- operating a first mode, in which a first estimation of the special property is made base on a derived received signal strength indicator, and- operating a second mode, in which a second estimation of the spatial property is made by Phase-Based Ranging and / or Round-Trip Time measurement, and- switching from the first mode to the second mode if the fulfillment of a criteria is detected.

20. The method according to claim 19, wherein the first mode comprises the following steps: computerized defining at least two first devices (4 - 11) (22, 24) for receiving a radio signal (S) that is being sent out from a second device (17) , wherein the at least two first devices (4 - 11) are located at different known positions, in particular within a room, in particular within the sales room or storage room, and the second device (17) is movable, and- computerized estimating the direction from which the radio signal was received based on representations of the reception signal strength delivered by each of the at least two first devices (4 - 11) as a result of receiving the radio signal at both of the at least two first devices (4 - 11) , or based on a representation of the reception signal strength delivered by a first of the at least two first devices (4 - 11) ) and either a lack of another representation from a second of the at least two first devices (4 - 11)TP0555 - 47 - as a result of non-reception of the radio signal or a message from the second of the at least two first devices ( 4 - 11 ) , which message indicates the non-reception of the radio signal at the second of the at least two first devices ( 4 - 11 ) .

Images