Secure Adaptive Wireless Communication

Abstract

A communication device includes a directional antenna and a control circuit. The directional antenna has a directional radiation pattern for directing greater power of a transmitted signal in a specific direction. The control circuit is coupled to the directional antenna and determines an angle and a distance to another device. Based on the determined distance and angle to the other device, the control circuit selects a security level for communication between the device and the other device from a plurality of security levels. In another embodiment, a method for transmitting data between the first device and the second device is provided.

Description

Technical Field

[0001] The present disclosure relates generally to communications and, more particularly, to secure adaptive wireless communications. Background Art

[0002] Various data communication technologies can be used to allow wireless access to a wide range of applications. Some of these wireless data communication technologies, such as WiFi, Bluetooth and near field communication (NFC) coexist in communication devices such as smart phones, tablet computers or handheld computers, and usually require dedicated components to implement each of the technologies. The communication technology used can be a trade-off between, for example, security, power consumption, network capabilities and data throughput. For example, WiFi may be preferred for high-speed, long-distance and large-scale network access that only requires a low security level for non-sensitive data. NFC may be preferred for high-security application types involving very sensitive information such as payment. NFC is safer than WiFi, but has a very short range and low data exchange rate. Due to the number of required components and the complexity of packaging these components into a limited space, it is very costly to integrate these different technologies together in a communication device.

[0003] Therefore, there is a need for a communication device that uses a single communication technology that combines greater security with longer range and higher data rates. Summary of the invention

[0004] According to one aspect of the present disclosure, a communication device is provided, comprising: a directional antenna having a directional radiation pattern for directing a greater power of a transmitted signal in a specific direction; and a control circuit coupled to the directional antenna, the control circuit determining an angle and a distance to another device, and based on the determined distance and angle to the other device, selecting a security level for communication between the device and the other device from a plurality of security levels.

[0005] In an embodiment, the directional antenna comprises an array of antenna elements for controlling the direction of the transmitted signal.

[0006] In an embodiment, the transmit signal is characterized as an ultra-wideband signal.

[0007] In an embodiment, said directional antenna comprises an array of antenna elements for receiving signals from said another device, wherein said array of antenna elements is used to determine said angle to said another device.

[0008] In an embodiment, the another device is selected from a plurality of devices and the remaining devices of the plurality of devices are not selected, and in response to the control signal selecting the security level, the directional antenna is directed to avoid transmitting the transmission signal to the unselected plurality of devices.

[0009] In an embodiment, the communication device further comprises an indicator for indicating the direction of the transmitted signal from the directional antenna.

[0010] In an embodiment, the direction of the directional antenna is randomly set and the direction is communicated to a user of the selected another device.

[0011] In an embodiment, a power level of the transmitted signal is adjusted based on the determined distance.

[0012] In an embodiment, the device has a fixed location and the other device is a mobile handheld device.

[0013] According to another aspect of the present disclosure, a method for transmitting data between a first device and a second device is contemplated, the method comprising: using the first device to scan other devices; detecting the second device by the first device; determining that communication with the second device is authorized; determining the distance between the first device and the second device; selecting a security level from multiple security levels based on the determined distance between the first device and the second device; adjusting a security parameter of the first device for the selected security level; and transmitting the data between the first device and the second device.

[0014] In an embodiment, the first device is fixed in a single location and the second device is a mobile handheld device.

[0015] In an embodiment, the method further comprises: directing an antenna of the first device away from other detected devices; adjusting transmit power to the antenna to reduce transmit range; and providing positioning information of a beam path from the antenna to a user of the second device.

[0016] In an embodiment, providing positioning information of a beam path from the antenna to a user of the second device additionally comprises providing an indication to the user of the second device where to position the second device in order to optimally receive the transmit data.

[0017] In an embodiment, the method further comprises adjusting a transmit power level of the first device based on the determined distance.

[0018] In an embodiment, selecting a security level from a plurality of security levels further comprises selecting the security level based on the determined distance and an angle from a projected centerline of the antenna direction.

[0019] According to another aspect of the present disclosure, a method for transmitting data between a first device and a second device is contemplated, the method comprising: using a directional antenna of the first device to scan other devices to receive signals from the other devices; using the first device to detect the second device; determining that communication with the second device is authorized; determining a position of the second device relative to the first device; selecting a security level from a plurality of security levels based on the relative position of the second device; adjusting security parameters of the first device for the selected security level; and transmitting the data between the first device and the second device.

[0020] In an embodiment, determining the relative position of the second device further comprises determining a distance and an angle to the second device based on a signal received from the second device.

[0021] In an embodiment, adjusting a security parameter of said first device for a selected security level further comprises adjusting a transmit power based on said determined distance to said second device.

[0022] In an embodiment, the method further comprises setting a transmission direction of an antenna of the first device to prevent the other device from intercepting the transmission data.

[0023] In an embodiment, the method further comprises providing information of the transmission direction of the first device by providing an indication to a user of the second device where to position the second device in order to optimally receive the transmission data. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention is illustrated by way of example and is not limited by the accompanying drawings, in which like reference numerals indicate like elements. Elements in the drawings are illustrated for simplicity and clarity and are not necessarily drawn to scale.

[0025] Figure 1 A device with security areas of different security levels and associated communication areas according to an embodiment is shown in a top view.

[0026] Figure 2 The method for Figure 1 The signal receiving path of the device.

[0027] Figure 3 The method for Figure 1 The signal transmission path of the device.

[0028] Figure 4 A secure transaction according to an embodiment is shown.

[0029] Figure 5 Another secure transaction according to another embodiment is shown in top view. DETAILED DESCRIPTION

[0030] Generally, in one embodiment, a device having the ability to transmit data at multiple security levels using a communication technology is provided. In the device, a security level is selected from multiple security levels based at least in part on the detected distance between the device and another device. The device includes a directional antenna array with multiple antenna elements, and the device can be fixed in one position. In one embodiment, if the detected distance between the devices is less than a first distance (e.g., 10 cm), communications involving highly sensitive data such as payment or access are enabled. If the detected distance between the devices is between the first distance and the second distance (e.g., 1 m to 5 m), communications involving data with medium sensitivity levels such as transportation ticketing, video / image sharing, etc. are allowed. Beyond the second distance, only data with low sensitivity can be transmitted, such as games, public information broadcasts, advertisements, etc. The antenna array allows beamforming to be used to provide a directional beam or form a transmit-receive area. In another embodiment, multiple security areas can be organized into pie-shaped sections, which are defined by the distance from the fixed device and by a predetermined angle away from the center line of the antenna array of the device. Moreover, beamforming can be used to focus and narrow the transmit signal by adjusting the power of the transmit signal. Beamforming can provide additional safety by directing the transmitted signal in a path that avoids unintended recipients. Also, the safety zone around the antenna can be moved and rearranged using beamforming. The fixture can contain an indicator such as a graphical display to allow the intended recipient of the transmission to properly position the mobile device in the beam for secure communications.

[0031] Providing secure communications in this manner allows the use of a single long range communications technology such as UWB to provide higher data rates than is achievable using, for example, NFC.

[0032] According to an embodiment, a communication device is provided, comprising: a directional antenna having a directional radiation pattern for directing a greater power of a transmitted signal in a specific direction; and a control circuit coupled to the directional antenna, the control circuit determining an angle and a distance to another device, and selecting a security level for communication between the device and the other device from a plurality of security levels based on the determined distance and angle to the other device. The directional antenna may include an array of antenna elements for controlling the direction of the transmitted signal. The transmitted signal may be characterized as an ultra-wideband signal. The directional antenna may include an array of antenna elements for receiving a signal from the other device, wherein the array of antenna elements is used to determine the angle to the other device. The other device may be selected from a plurality of devices, and the remaining devices in the plurality of devices are not selected, wherein in response to the control signal selecting the security level, the direction of the directional antenna may be set to avoid transmitting the transmitted signal to the unselected plurality of devices. The device may further include an indicator for indicating the direction of the transmitted signal from the directional antenna. The direction of the directional antenna may be randomly set and wherein the direction is communicated to a user of the selected other device. The power level of the transmitted signal may be adjusted based on the determined distance. The device may have a fixed location and the other device a mobile handheld device.

[0033] In another embodiment, a method of transmitting data between a first device and a second device is provided, the method comprising: scanning for other devices using the first device; detecting the second device by the first device; determining that communication with the second device is authorized; determining a distance between the first device and the second device; selecting a security level from a plurality of security levels based on the determined distance between the first device and the second device; adjusting a security parameter of the first device for the selected security level; and transmitting the data between the first device and the second device. The first device may be fixed in a single location, and the second device is a mobile handheld device. The method may further comprise: directing an antenna of the first device away from other detected devices; adjusting a transmit power to the antenna to reduce a transmit range; and providing positioning information of a beam path from the antenna to a user of the second device. Providing positioning information of a beam path from the antenna to the second device may further comprise providing an indication to a user of the second device where to position the second device to best receive the transmitted data. The method may further comprise adjusting a transmit power level of the first device based on the determined distance. Selecting a security level from a plurality of security levels may further comprise selecting the security level based on the determined distance and an angle from a projected centerline of the antenna direction.

[0034] In yet another embodiment, a method for transmitting data between a first device and a second device is provided, the method comprising: using a directional antenna of the first device to scan other devices to receive signals from the other devices; using the first device to detect the second device; determining that communication with the second device is authorized; determining the position of the second device relative to the first device; selecting a security level from a plurality of security levels based on the relative position of the second device; adjusting security parameters of the first device for the selected security level; and transmitting the data between the first device and the second device. Determining the relative position of the second device may further comprise determining a distance and angle to the second device based on signals received from the second device. Adjusting the security parameters of the first device for the selected security level may further comprise adjusting a transmit power based on the determined distance to the second device. The method may further comprise setting a transmission direction of the antenna of the first device to avoid interception of the transmission data by the other device. The method may further comprise providing information of the transmission direction of the first device by providing an indication to a user of the second device where to position the second device to best receive the transmission data.

[0035] Figure 1 A communication zone according to an embodiment is shown in a top view, with security zones of different security levels associated with a device 10. The device 10 may be a device for wirelessly communicating with other devices such as devices 12, 14, and 16 within the communication range of the device 10. In one embodiment, the device 10 is a device that is fixed in one location to provide various services that require different security levels, such as banking, payment, access, transportation, etc. The other devices 12, 14, and 16 may be mobile devices such as smartphones and other wireless handheld communication devices.

[0036] The device 10 and other devices may communicate using relatively long range (e.g., 10 m) and high speed communication technologies such as WiFi or ultra-wideband (UWB). The detected device location is used to control the exchange of data between the device 10 and another device at one of a plurality of different security levels based on the device location relative to the device 10. In contrast, typically, highly secure communications, such as contactless payments, rely on extremely short range communications that may be provided using near field communications (NFC), where the communication distance is only a few centimeters (cm) on average.

[0037] Figure 1The communication area of ​​​​the device 10 is organized into three areas, wherein the pie-shaped areas shown are arranged as a security area Z1, a security area Z2, and a security area Z3. In other embodiments, the number of security areas may be different. Security area Z1 has the highest security level among the three security areas. Security area Z2 has a medium security level, and security area Z3 has the lowest security level. Devices located in security area Z1, such as device 12, can perform communications of any type of security level (high security level, medium security level, and low security level). Device 14 in medium security area Z2 only allows medium security level and low security level communications. Devices in security area Z3, such as device 16, are only entitled to low security communications. Typically, according to a preferred embodiment, device 10 will perform a discovery phase to determine the locations of other available devices 12, 14, and 16. There are various methods for the device to determine the location. After determining the location, the device will apply security level restrictions based on the determined location as shown in the figure. Then one of the devices 12, 14, and 16 can be selected for communication using the appropriate security level.

[0038] Applying security levels to devices based on relative location allows high communication speeds without compromising security. This also provides the flexibility to use the same communication technology for various communication types, rather than employing a different communication technology for each communication type.

[0039] Figure 2 A signal receiving path 20 for a device such as device 10 according to an embodiment is shown. As discussed above, device 10 may be located at a fixed location or at a location that does not change frequently. Signal receiving path 20 includes antenna 24, amplifiers 32, 34 and 36, phase difference detector 38 and processor 40. Antenna 24 is an antenna array including multiple antenna elements represented by antenna elements 26, 28 and 30. The optimal physical distance between the antenna elements of the antenna array for beamforming and spatial angle detection is related to the frequency / wavelength of the signal used. The higher the frequency, the shorter the optimal distance between the antenna elements of the antenna array. Therefore, gigahertz (GHz) range signals are suitable for more compact antenna arrays. UWB technology is also suitable for short pulse carriers and free direct sequence communication modes (IR-UWB), ideally suitable for device positioning and multi-band OFDM (MBOFDM) communication modes, which are robust to interference and provide multi-path high-speed data communication. Amplifiers 32, 34 and 36 are connected to corresponding ones of antenna elements 26, 28 and 30. For example, amplifier 32 has an input connected to antenna element 30. Phase difference detector 38 has an input connected to an output of each of amplifiers 32, 34, and 36. An output of phase difference detector 38 is connected to processor 40. Figure 2Only one example of signal receive path circuitry is shown. Different signal receive paths may be implemented in other embodiments using different components. It should be noted that processor 40 and phase difference detector 38 may be implemented together on a single integrated circuit or separately on multiple integrated circuits.

[0040] When the device 10 ( Figure 1 ), device 10 attempts to determine the relative position of device 22. Device 10 first broadcasts an interrogation signal in all directions, and device 22 responds with a reply signal. The time difference T is calculated between the moment when the interrogation device sends out the interrogation signal consisting of a high-frequency radio frequency (RF) pulse and the moment when device 10 receives the reply from the interrogation device 22, also in the form of a high-frequency RF pulse. DIFF The distance d1 is determined. The time measurement may be accomplished, for example, by a timer in the processor 40. The timer is started when the interrogation signal is transmitted and stopped when a reply is received from the interrogating device. The distance d1 between the devices is then d1 = (T DIEF -T OP ) / c, where T OP is the duration required for the interrogator to process and transmit back a response, and c is the propagation speed of electromagnetic waves (3x 10 8 m / s).

[0041] The spatial angle α1 is defined by measuring the signal phase difference of the RF pulses received by each antenna element 26, 28 and 30 at a given time. The antenna elements 26, 28 and 30 form an equally spaced antenna array. The left path is shown from the antenna element 30 to the device 22, the center path is shown from the antenna element 28, and the right path is shown from the antenna element 26. The phase difference detector 38 determines the phase difference of the right path and the left path compared to the middle path. The middle path acts as a reference path. In the first configuration, the interrogation device 22 is positioned at an angle α1 relative to the centerline 42 of the antenna array 24. The received signal travel path of the left path is shorter than the received signal path of the middle path, and the received signal travel path of the right path is longer than the middle path. This results in a negative phase difference (ψ LEFT -ψ REF ) and the positive phase difference (ψ RIGHT -ψ REF ), where ψ represents the phase. In addition to the sign, the higher the difference in the signal paths, the greater the value of the phase difference. It should be noted that if the device 22 is located on the other side of the center line 42, the right path will have a negative phase difference and the left path will have a positive phase difference.

[0042] The detection distance d1 and the spatial angle α1 in the above equation are processed by the processor 40. Using the detection distance d1 and the spatial angle α1, the processor 40 can determine the relatively accurate spatial position of the interrogation device relative to the device 10. As part of the response, the interrogation device 22 can also provide other information, such as the type of communication supported, the required security level, and / or the sensitivity of the data to be transmitted.

[0043] Figure 3 It shows that according to the embodiment Figure 1 The signal transmission path 50 of the device 10. The signal transmission path 50 includes a plurality of transmission paths ( Figure 3 The three representative paths in FIG. 1 ). Each path is coupled to an antenna element of antenna array 52. ​​Antenna array 52 and antenna array 24 ( Figure 2 ) can be the same antenna array. Antenna array 52 provides a directional antenna with a controllable radiation pattern so that the transmitted signal has greater power in a specific direction. Each transmission path consists of a controllable phase shifter and a controllable amplifier. Specifically, signal transmission path 50 includes antenna 52, amplifiers 60, 62 and 64, controllable phase shifter circuits 66, 68 and 70, controller 72, signal generator 78 and processor 80. Signal generator 78 has an output connected to the input of controllable phase shifter circuits 66, 68 and 70. Controllable phase shifter circuits 66, 68 and 70 have outputs connected to the input of amplifiers 60, 62 and 64. Antenna 52 includes antenna element arrays 54, 56 and 58. Amplifiers 60, 62 and 64 are connected to provide an amplified signal to a corresponding one of antenna elements 58, 56 and 54. Controller 72 adjusts the phase shift and gain of each transmission path respectively to achieve the desired transmission beam characteristics (i.e., beam width, angle and communication distance). As shown, the output of each amplifier has an amplitude A and a phase ψ. For example, amplifier 60 provides an output having an amplitude A1 and a phase ψ1, amplifier 62 provides an output having an amplitude A2 and a phase ψ2, and amplifier 64 provides an output having an amplitude A3 and a phase ψ3. Processor 80 oversees the operation of controller 72 and signal generator 78. It should be noted that processor 80, controller 72, and signal generator 78 may be implemented as a single integrated circuit or by using multiple integrated circuits.

[0044] In one embodiment, as described above, in order to avoid exposure to potential hacker attacks, communication of data with a given sensitivity level can only be achieved when the device to be communicated with is within a given distance from the device 10, such as Figure 1As shown. For example, communications involving highly sensitive personal data such as payment and access control can only be initiated when the detected distance between the devices is below a first level (e.g., 10 cm). The exchange of data with a medium sensitivity level, such as transportation ticketing, video / image sharing, etc., may allow a distance of up to a second level (1m to 5m). Beyond the second security level, only data communications with a low sensitivity level may be allowed (games, public information broadcasts, advertising, etc.). A chart stored in the device 10 may provide a correspondence between device distances and authorized data sensitivity levels for exchange. While three data sensitivity levels appear to be optimal, any number of levels may be considered as needed.

[0045] For relatively long range communication technologies such as UWB, additional steps may be performed to further protect the sensitive data being exchanged. For example, the transmit power provided for the transmitted signal may be adjusted to a level that is only sufficient to communicate at the detection distance. Furthermore, beamforming of the beam 82 radiated from the antenna 52 may be performed to reduce the spatial coverage to a limited area around the detection location of other devices and to change the direction of the transmitted signal. The use of beamforming ensures more secure communications while taking advantage of a technology that has a longer range and higher speed than, for example, NFC. As with the detection of the spatial angle of the target device, beamforming is achieved using an antenna array 52 having multiple antenna elements, such as Figure 3 As shown. Each individual antenna element is supplied with radio frequency (RF) pulses of different amplitude and phase. Changing the amplitude A and phase ψ of the transmit signal provides steering the transmit signal towards a given direction, i.e., determined by the angle α2 relative to the antenna centerline 84. Thus, by narrowing or widening the beam 82, the range of the beam 82 is limited to a given distance d2 and has a given spatial coverage.

[0046] A possible situation is in a store with a wireless device in a fixed location. The device can provide several services, such as paying for purchases (high sensitivity data exchange) and broadcasting advertisements to smartphones of customers located nearby (low sensitivity data exchange). A customer with a smartphone approaches the device 10 to initiate a contactless payment transaction. The device 10 detects that the smartphone is within a safe distance and accepts the contactless payment request. The fixed device 10 then randomly selects a signal beam direction and provides an indication of such direction on the interface. The interface is visible only to customers in front of the device 10. The selected direction is preferably not in a straight line between the device 10 and one or more of the customers in line. Next, the customer places his smartphone in the area indicated by the interface to complete the secure transaction.

[0047] Figure 4A secure transaction according to another embodiment is shown. As shown, the signal transmission direction can be changed by manipulating the transmitted signal in a direction that makes it less likely to be intercepted by an attacker. In one embodiment, the signal can be directed in any direction. The fixed device 92 scans other devices. The fixed device 92 determines the location of each of the devices detected within the range. The mobile device 102 owned by the customer 98 is selected for the requested transaction. Based on the desired type of communication, it is determined whether the location of the mobile device 102 is within an area with an appropriate security level. Then, the device 102 selects the necessary security level and adjusts the security parameters for communication under the selected security level. Only one device can be selected for communication at a time. When the beam 94 is transmitted, the fixed device 92 determines the safe direction so that other detected but unselected devices are not in the beam path 96. As guided by the interface 93, the customer 98 keeps the mobile device 102 in the beam path 96 of the beam 94 to intercept the beam so as to best receive the transmitted data and communicate with the device 92. In a well-known environment, such as a payment area in a store, this embodiment may be desirable. More specifically, after locating the device 102 and determining that sensitive data exchange is requested and approved, the beam of the communication fixture 92 can be steered in a fixed direction but significantly away from the customer's queue line (e.g., toward the ceiling) to avoid communication interception by mobile devices of other customers 100. The location of the beam direction 96 can be indicated on the interface 93 to the customer 98 so that the customer 98 knows where to hold the device. The interface 93 can be a graphical interface with a display that is not visible to other customers 100. In one embodiment, the position of the circle 108 on the screen of the interface 93 indicates the position of the beam (see Figure 4 Inset of an enlarged view of the middle interface 93).

[0048] Figure 5 Another secure transaction according to another embodiment is shown in top view. Figure 5 In Figure 1, a customer 99 with a smartphone 110 conducts a transaction with a fixed device 104. Other customers 102 are waiting in line nearby. If modulating the transmission power and beamforming are not sufficient to protect the signal from a persistent attacker, randomly changing the beam direction can further reduce the risk of interception. The beam can be randomly pointed in different directions so that the beam is not always pointed in the same direction and is not towards the direction of other customers 102. Figure 5 , the fixed device 104 may randomly select a beam direction and display the location of the beam 103 on the interface 105 as the location 109 of the client 99 (see the enlarged view of the interface 105). The client 99 holds the mobile device 110 in the beam for data transfer. The direction of the beam 103 may randomly change to another direction, and the location 109 on the interface 105 will be updated accordingly, enabling the client 99 to reposition the device 110.

[0049] Various embodiments or portions of embodiments may be implemented in hardware or as instructions on a non-transitory machine-readable storage medium, which includes any mechanism for storing information in a form readable by a machine, such as a personal computer, laptop, file server, smart phone, or other computing device. Non-transitory machine-readable storage media may include volatile and non-volatile memory, such as read-only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory, etc. Non-transitory machine-readable storage media do not include transitory signals.

[0050] Although the present invention is described herein with reference to specific embodiments, various modifications and changes may be made without departing from the scope of the present invention as set forth in the appended claims. Therefore, the description and drawings should be regarded as illustrative rather than restrictive, and all such modifications are expected to be included within the scope of the present invention. It is not intended that any advantages, advantages, or solutions to problems described herein with respect to specific embodiments be construed as key, essential, or requisite features or elements of any or all claims.

[0051] In addition, as used herein, the term "a" is defined as one or more than one. Moreover, the use of introductory phrases such as "at least one" and "one or more" in the claims should not be interpreted as implying that another claim element introduced by the indefinite article "a" limits any particular claim containing this introduced claim element to an invention containing only one of this element, even when the same claim contains the introductory phrases "one or more" or "at least one" and an indefinite article such as "a". The same applies to the use of definite articles.

[0052] Unless otherwise stated, terms such as "first" and "second," etc., are used to arbitrarily distinguish between the elements such terms describe. Therefore, these terms are not necessarily intended to indicate temporal or other prioritization of such elements.

Claims

1. A communication device, characterized in that: It includes: A directional antenna having a directional radiation pattern for directing the power of a transmitted signal in a specific direction along an antenna centerline of the directional antenna; as well as a control circuit coupled to the directional antenna, the control circuit determining an angle and a distance to another device and selecting a security level for communications between the device and the other device from a plurality of security levels based on the determined distance and angle to the other device, wherein the plurality of security levels correspond to different security areas organized as pie-shaped segments, the pie-shaped segments being defined by distances from the centerline of the antenna and by predetermined angles away from the centerline of the antenna, and wherein selecting the security level comprises determining a location of the other device based on the determined distance and angle to the other device, selecting one of the security zones based on the location, and selecting a security level belonging to the selected security zone, wherein the directional antenna comprises an array of antenna elements for controlling the direction of the transmitted signal, wherein a directional antenna of the communication device is directed away from another detected device, wherein a transmit power to the directional antenna is adjusted to reduce a transmit range, and wherein positioning information of a beam path from the directional antenna to a user of the other device is provided, wherein the another device is selected from a plurality of devices and the remaining devices of the plurality of devices are not selected, wherein in response to the control signal selecting the security level, the directional antenna is set in a direction to avoid transmitting the transmission signal to the unselected plurality of devices, and wherein the apparatus further comprises an indicator for indicating the direction of the transmitted signal from the directional antenna, And wherein said direction of said directional antenna is randomly set and wherein said direction is communicated to a user of a selected another device.

2. The device according to claim 1, characterized in that The transmitted signal is characterized as an ultra-wideband signal.

3. The device according to claim 1, characterized in that The directional antenna comprises an array of antenna elements for receiving signals from the other device, wherein the array of antenna elements is used to determine the angle to the other device.

4. The device according to claim 1, characterized in that A power level of the transmitted signal is adjusted based on the determined distance.

5. The device according to claim 1, characterized in that The device has a fixed location and the other device is a mobile handheld device.

6. A method for transmitting data between a first device and a second device, characterized in that: The method comprises: Scanning other devices using the first device; detecting, by the first device, a second device; determining that communication with the second device is authorized; determining the location of the second device by determining the distance and angle to the second device using an antenna at the first device, wherein the antenna has a directional radiation pattern for directing power of a transmitted signal along a centerline of the antenna; selecting a security level from a plurality of security levels based on the location of the second device; adjusting security parameters of the first device for a selected security level; and transmitting the data between the first device and the second device, wherein the plurality of security levels correspond to different security areas organized as pie-shaped segments, the pie-shaped segments being defined by distances from the centerline of the antenna and by predetermined angles away from the centerline of the antenna, and wherein selecting the security level comprises selecting one of the security areas based on the location of the second device, and selecting a security level belonging to the selected security area, wherein the directional antenna comprises an array of antenna elements for controlling the direction of the transmitted signal, wherein directing the antenna of the first device away from other detected devices, adjusting the transmit power to the antenna to reduce the transmit range, and providing positioning information of a beam path from the antenna to a user of the second device, wherein the another device is selected from a plurality of devices and the remaining devices of the plurality of devices are not selected, wherein in response to the control signal selecting the security level, the directional antenna is set in a direction to avoid transmitting the transmission signal to the unselected plurality of devices, and wherein the apparatus further comprises an indicator for indicating the direction of the transmitted signal from the directional antenna, And wherein said direction of said directional antenna is randomly set and wherein said direction is communicated to a user of a selected another device.

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