SE542171C2

SE542171C2 - Determining a position of a portable electronic device

Info

Publication number: SE542171C2
Application number: SE1850083A
Authority: SE
Inventors: Joel Sahlén
Original assignee: Total Security Stockholm Ab
Priority date: 2018-01-25
Filing date: 2018-01-25
Publication date: 2020-03-03
Also published as: SE1850083A1

Abstract

In accordance with one or more embodiments herein, a system 100 for determining the position of a portable electronic device 120 is provided. The system 100 comprises: a plurality of sound emitting devices 110, each configured to emit a different unique sound signature; at least one data storage 130, configured to store information regarding which sound emitting device 110 emits which unique sound signature, and the position of each sound emitting device 110; at least one portable electronic device 120 comprising a sound receiving device 125, such as a microphone, configured to receive sound emitted by the sound emitting devices 110; and at least one processing device 140, configured to determine, based on sound received by the sound receiving device 125 and information stored in the data storage 130, a position of the portable electronic device 120.

Description

DETERMINING A POSITION OF A PORTABLE ELECTRONIC DEVICE TECHNICAL FIELD The present disclosure relates generally to systems and methods for determining a position of a portable electronic device.

BACKGROUND US20150181014 describes a method of controlling a locking mechanism using a portable electronic device, where a web service receives credentials or a command from a software application on the portable electronic device and issues a command for receipt by the lock.

US9640004 describes a method of operating a lock from a portable remote device, where a radio frequency identification signal sent from the portable remote device to a controller for the lock is used for identifying the portable remote device as an authorized user of the lock.

PROBLEMS WITH THE PRIOR ART In the methods described in US20150181014 and US9640004, there is no way of automatically determining which door the user of the portable electronic device wishes to unlock.

There is thus a need for a method for determining the position of a portable electronic device.

SUMMARY The above described problem is addressed by the claimed system for determining a position of a portable electronic device. The system may comprise: a plurality of sound emitting devices, each configured to emit a different unique sound signature; at least one data storage, configured to store information regarding which sound emitting device emits which unique sound signature, and the position of each sound emitting device; at least one portable electronic device comprising a sound receiving device, such as e.g. a microphone, configured to receive sound emitted by the sound emitting devices; and at least one processing device, configured to determine, based on sound received by the sound receiving device and information stored in the data storage, a position of the portable electronic device, wherein a first sound emitting device of the plurality of sound emitting devices is positioned in the vicinity of a first entrance granting arrangement, such as a door unlocking and/or opening arrangement, and entrance granting information is transmitted to the first entrance granting arrangement if the sound received by the sound receiving device corresponds to the unique sound signature emitted by the first sound emitting device. This enables the system to determine a position of a portable electronic device in a simple way.

The above described problem is further addressed by the claimed method for determining a position of a portable electronic device. The method may comprise: emitting a different unique sound signature from each of a plurality of sound emitting devices; storing information regarding which sound emitting device emits which unique sound signature, and the position of each sound emitting device, in a data storage; receiving sound emitted by at least one sound emitting device in a sound receiving device, such as e.g. a microphone, comprised in a portable electronic device; determining, based on sound received by the sound receiving device and information stored in the data storage, a position of the portable electronic device, and transmitting entrance granting information to a first entrance granting arrangement, such as a door unlocking and/or opening arrangement, if the sound received by the sound receiving device corresponds to the unique sound signature emitted by a first sound emitting device of the plurality of sound emitting devices positioned in the vicinity of said first entrance granting arrangement. This method enables the determination of a position of a portable electronic device in a simple way.

The entrance granting information may e.g. be transmitted from the portable electronic device to the first entrance granting arrangement, e.g. in the form of a QR code displayed on a display of the portable electronic device and viewed by a camera in the first entrance granting arrangement. This is a convenient way of transmitting entrance granting information from a portable electronic device to an entrance granting arrangement.

In embodiments, information about the sound received by the sound receiving device is transmitted to at least one central electronic arrangement, such as e.g. a central server arrangement, in which the determination of the position of the portable electronic device takes place. This enables centralized control over all parts of the system, as well as e.g. centralized setting of authorizations to various locations.

In embodiments, the entrance granting information is transmitted from the central electronic arrangement to the first entrance granting arrangement. Alternatively, the entrance granting information is transmitted from the central electronic arrangement to the portable electronic device. This enables entrance granting information to be transmitted to the first entrance granting arrangement even if there is no connection between the central electronic arrangement and the first entrance granting arrangement.

The entrance granting information may e.g. be transmitted from the central electronic arrangement to the portable electronic device in the form of a QR code. The entrance granting information may e.g. be displayed on a display of the portable electronic device and viewed by a camera in the first entrance granting arrangement.

In embodiments, the unique sound signature is a sound of a specific frequency, or a sound where different specific frequencies follow each other according to a pattern. The unique sound signature however preferably comprises only sound of one specific frequency at each point in time, so that it may be determined which of the sounds received by the sound receiving device belong to a unique sound signature. Other sounds received by the sound receiving device may e.g. be general ambient noise, or sounds from other sound emitting devices further away.

In embodiments, the sound received with the highest amplitude by the sound receiving device is filtered out, and the determination of the position of the portable electronic device is based on only this sound. This enables the filtering away of ambient noise and sounds from other sound emitting devices further away.

The unique sound signature may e.g. consist of frequencies that are inaudible to human ears, such as e.g. frequencies from 16 kHz to 96 kHz. This enables the use of high amplitude sound without this being disturbing for humans.

In embodiments, the unique sound signature changes over time. This may enhance the security, since knowledge of the most recent unique sound signatures will then always be required.

The term portable electronic device covers any electronic device that is not stationary, and may thus cover also e.g. an electronic device that is stationarily mounted on a movable device such as e.g. a vehicle or a cart. The portable electronic device may e.g. be a mobile phone, such as e.g. a smartphone. The portable electronic device may alternatively be another type of portable electronic device, such as e.g. a self scanning device.

The at least one data storage may e.g. be at least one memory. The at least one data storage may however be any type of data storage where information may be stored regarding which sound emitting device emits which unique sound signature, and the position of each sound emitting device.

The at least one processing device may be a local processing device, a central processing device, or a number of local and/or central processing devices between which signals are transmitted. Some processing may e.g. take place in one local and/or central processing device, and signals may then be transmitted to one or more other local and/or central processing devices for further processing.

The scope of the invention is defined by the claims, which are incorporated into this section by reference. A more complete understanding of embodiments of the invention will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more embodiments. Reference will be made to the appended sheets of drawings that will first be described briefly.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 schematically illustrates a system for determining a position of a portable electronic device, in accordance with one or more embodiments described herein.

Figure 2 schematically illustrates a system arranged in a building for determining a position of a portable electronic device, in accordance with one or more embodiments described herein.

Figure 3 schematically illustrates a system arranged in a location for determining a position of a portable electronic device, in accordance with one or more embodiments described herein.

Figures 4a-4c schematically illustrate systems for determining a position of a portable electronic device and granting access to a location, in accordance with embodiments described herein.

Figure 5 schematically illustrates a method for determining a position of a portable electronic device, in accordance with one or more embodiments described herein.

Embodiments of the present disclosure and their advantages are best understood by referring to the detailed description that follows. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures.

DETAILED DESCRIPTION A number of different keyless lock operating systems using portable electronic devices are known, but they all require that the portable electronic device knows which door that is to be unlocked (or is arranged to be able to unlock only one door). If a system comprises more than one door, there is no way in existing systems to automatically determine which door the user of the portable electronic device wishes to unlock.

A method for determining a position of a portable electronic device could be used for determining which door a user of the portable electronic device wishes to unlock, but also for other purposes, such as e.g. tracking the movement of users of portable electronic devices.

The present disclosure relates generally to systems and methods for determining a position of a portable electronic device. Embodiments of the disclosed solution are presented in more detail in connection with the figures. The term portable electronic device in the present disclosure covers any electronic device that is not stationary, and may thus cover also e.g. an electronic device that is stationary mounted on a movable device such as e.g. a vehicle or a cart.

Figure 1 schematically illustrates a system 100 for determining a position of a portable electronic device 120, which may e.g. be a mobile phone, such as e.g. a smartphone. The system 100 shown in figure 1 comprises three sound emitting devices 110a, 110b, 110c, each configured to emit a different unique sound signature Fa, Fb, FoThe system 100 further comprises a data storage 130, such as e.g. a memory, and a processing device 140. The data storage 130 stores information regarding which sound emitting device 110a, 110b, 110c emits which unique sound signature F, and the position of each sound emitting device 110a, 110b, 110c. The portable electronic device 120 comprises a sound receiving device, such as a microphone 125, configured to receive sound emitted by the sound emitting devices 110a, 110b, 110c. Based on this sound and the information stored in the data storage 130, the processing device 140 may determine a position of the portable electronic device 120.

The microphone 125 in the portable electronic device 120 will usually receive more than one sound at each point in time, so it may be advantageous to at each point in time filter out only the sound received with the highest amplitude by the microphone 125. The unique sound signature F may be a sound of a specific frequency, or a sound where different specific frequencies follow each other according to a pattern. The unique sound signature F however preferably comprises only sound of one specific frequency at each point in time, so that it may be determined which of the sounds received by the microphone belong to a unique sound signature F. Other sounds received by the microphone may e.g. be general ambient noise, or sounds from other sound emitting devices further away.

The unique sound signature F may change over time, so that e.g. a particular sound emitting device 100a has a unique sound signature F that is a sound of a first frequency at a first point in time, such as e.g. a first day, and a sound of a second frequency at a second point in time, such as e.g. a second day. If the unique sound signature F is a sound where different specific frequencies follow each other according to a pattern, the pattern may also change from a first point in time to a second point in time. This may enhance security in the system, since knowledge of the most recent unique sound signatures will then be required.

The unique sound signature preferably consists of frequencies that are inaudible to human ears, so as not to be disturbing for humans. Such frequencies may e.g. range from 16 kHz to 96 kHz.

It may be desirable not to operate the microphone 125 at all times, e.g. to save battery. The microphone 125 may then be triggered to start based on a detected event in the portable electronic device 120, such as e.g. movement detected using in-built gyro sensors in the portable electronic device 120. There may e.g. be a software application in the portable electronic device 120 that controls the operation of the microphone 125.

The microphone 125 may e.g. be arranged to only be active for a certain time, such as e.g. 10 seconds, after activation of the software application.

Figure 2 schematically illustrates a system 100 arranged in a building 200 for determining a position of a portable electronic device 120. The building 200 comprises a number of doors 250, and in the vicinity of each door 250, a sound emitting device 210 is positioned. If a person carrying a portable electronic device 120 moves through the building 200, the microphone 125 in the portable electronic device 120 will receive sound emitted by the sound emitting devices 210.

In some positions within the building 200, the microphone 125 in the portable electronic device 120 will receive sound emitted by more than one sound emitting device 210. For example, a person standing between doors 250e and 250f will receive at least sound emitted by both sound emitting device 21 Oe and sound emitting device 210f. However, if the sound received with the highest amplitude by the microphone 125 is determined, it may be determined whether the portable electronic device 120 is closer to door 250e or door 250f. The exact position of the portable electronic device 120 will thus not be determined, but it will at least be determined which of the doors 250 the portable electronic device 120 is closest to, and that it is close enough for the microphone 125 to receive sound emitted by a sound emitting device 210.

The determined position of the portable electronic device 120 may be used for granting access to a location, such as e.g. a building or a room. A portable electronic device 120 carried by a person approaching the door 250a, which is the entrance door to building 200, may when the portable electronic device 120 is close enough to door 250a receive sound emitted by sound emitting device 210a in the microphone 125 of the portable electronic device 120. Based on stored information regarding which sound emitting device 210 emits which unique sound signature F and the position of each sound emitting device 210, the processing device 140 may determine that the portable electronic device 120 is in the vicinity of door 250a. If the user of the portable electronic device 120 is authorized to be granted access to building 200, door 250a may then be automatically unlocked.

Figure 3 schematically illustrates a system 100 arranged in a location 300 for determining a position of a portable electronic device 120. The system 100 shown in figure 3 is not used for granting access to locations. Instead, the purpose of the system 100 shown in figure 3 is to track the movement of persons carrying portable electronic devices 120. It may e.g. be desirable to track the movement of persons within the location 300, which may e.g. be a supermarket or a shopping mall. The disclosed positioning system may also be used to provide positioning information to the user of a portable electronic device 120 in situations where the GPS system does not function satisfactorily, such as e.g. in a shopping mall. The disclosed positioning system may then e.g. be used to provide positioning information in relation to a map over the premises provided in a software application in the portable electronic device 120.

If the portable electronic device 120 also registers purchases, e.g. by the portable electronic device 120 being a self scanning device, which may e.g. be mounted on a cart, statistics may e.g. be collected regarding the movement of buyers in connection with their purchases.

Another situation where the disclosed positioning system may be useful is in a car park. If the portable electronic device 120 is mounted in a vehicle, the position of the vehicle within the car park may be determined. This may e.g. be used for payment, or for helping the user of the vehicle to find it within the car park.

In figure 3, a number of sound emitting devices 310 are positioned. When a person or vehicle carrying a portable electronic device 120 moves through the location 300, the microphone 125 in the portable electronic device 120 will receive sound from different sound emitting devices 310. The dotted lines in figure 3 show sectors a-i of location 300. When a person or vehicle carrying a portable electronic device 120 e.g. moves through sector e, the microphone 125 in the portable electronic device 120 will receive sound emitted at least by sound emitting device 31 Oe. Most probably, the microphone 125 in the portable electronic device 120 will receive sound emitted also by other sound emitting devices 310, but the sound emitted by sound emitting device 31 Oe will have the highest amplitude. The exact position of the portable electronic device 120 will thus not be determined, but it will at least be determined which of the sectors a-i the portable electronic device 120 is likely to be positioned within.

A system 100 for determining a position of a portable electronic device 120 may also be used for both tracking movement and granting access to locations within the same system, or for determining the position of a portable electronic device 120 for other reasons. A system 100 for determining a position of a portable electronic device 120 may thus be used for many different purposes.

Figure 4a schematically illustrates a system 100 for determining a position of a portable electronic device 120 and granting access to a location. A sound emitting device 410 is positioned in the vicinity of a door 450 and emits a unique sound signature F that is received by the microphone 125 of the portable electronic device 120. In response to this sound, entrance granting information in the form of a QR code is displayed in a display 128 of the portable electronic device 120. The entrance granting information is transmitted to an entrance granting arrangement 470 by the QR code being viewed by a camera 460 connected to the entrance granting arrangement 470. The entrance granting arrangement 470 may e.g. be a door controller such as e.g. the Axis A1001 Network Door Controller operating with a relay that is used to lock or unlock the door 450.

The data storage 130 may be comprised in the portable electronic device 120, and store also authorization information (in addition to the information regarding which sound emitting device emits which unique sound signature F and the position of each sound emitting device). The processing device 140 may in the same way be a local processing device in the portable electronic device 120. In this case, entrance granting information may e.g. be generated or retrieved from the data storage 130 by a software application in the portable electronic device 120, and be transmitted from the portable electronic device 120 to the entrance granting arrangement 470, e.g. using the display 128 and the camera 460.

Figure 4b schematically illustrates another system 100 for determining a position of a portable electronic device 120 and granting access to a location. As described in connection with figure 4a, a sound emitting device 410 positioned in the vicinity of a door 450 emits a unique sound signature F that is received by the microphone 125 of the portable electronic device 120. Information about this unique sound signature F is transmitted to a central electronic arrangement 480, which may e.g. be a central server arrangement. In this case, the data storage 130 and the processing device 140 are preferably comprised in the central electronic arrangement 480. There may however be data storage and/or a local processing device also in the portable electronic device 120, cooperating with the data storage 130 and/or the processing device 140 in the central electronic arrangement 480. The entrance granting information may in this case be transmitted from the central electronic arrangement 480 to the a portable electronic device 120, from which it may be transmitted to the entrance granting arrangement 470 in the same way as described in connection with figure 4a.

Figure 4c schematically illustrates another system 100 for determining a position of a portable electronic device 120 and granting access to a location. As described in connection with figure 4a, a sound emitting device 410 positioned in the vicinity of a door 450 emits a unique sound signature F that is received by the microphone 125 of the portable electronic device 120. As described in connection with figure 4b, information about this unique sound signature F is transmitted to a central electronic arrangement 480. The central electronic arrangement 480 may then in this case transmit entrance granting information directly to the entrance granting arrangement 470.

In all of the embodiments described above, the processing device 140 will be able to determine that the portable electronic device 120 is in the vicinity of the door 450 based on the information stored in the data storage 130 about the unique sound signature F being emitted by the sound emitting device 410, and the position of the sound emitting device 410. The processing device 140 may then determine whether the user of the portable electronic device 120 is authorized to be granted access to the location in question, e.g. based on authorization information stored in the data storage 130. If it is determined that the user of the portable electronic device 120 is authorized, the door 450 may be automatically unlocked.

The described entrance authorization is safer than just the use of e.g. a QR code, since the portable electronic device 120 that is to be given access must have the software application installed and be able to determine in the vicinity of which door 450 it is positioned. If the unique sound signature consists of frequencies that are inaudible to human ears, such as e.g. frequencies from 16 kHz to 96 kHz, the unique sound signature may not be transmitted over the telephone network, and this further increases security. The entrance authorization may also be combined with other types of user access control, such as e.g. a card, a PIN and/or a mobile Bank ID, in order to further increase security.

In order for the door 450 to be unlocked, entrance granting information must be transmitted to the entrance granting arrangement 470. As explained above, this may be done in different ways. If the system 100 comprises a central electronic arrangement 480, the entrance granting information may be transmitted to the entrance granting arrangement 470 directly from the central electronic arrangement 480, but it may also be transmitted from the central electronic arrangement 480 to the portable electronic device 120, and from the portable electronic device 120 to the entrance granting arrangement 470. It is then e.g. possible to use the display 128 of the portable electronic device 120 for transferring the entrance granting information to the entrance granting arrangement 470, e.g. in the form of a QR code, if the entrance granting arrangement 470 comprises a camera 460.

If the data storage 130 is comprised in the portable electronic device 120 and also comprises authorization information, the entrance granting information may be generated, or stored and retrieved, in the portable electronic device 120 and transferred to the entrance granting arrangement 470, e.g. in the form of a QR code displayed in the display 128 of the portable electronic device 120 and viewed by a camera 460 in the entrance granting arrangement 470.

The processing device 140 may be located in the portable electronic device 120, or in a central electronic arrangement 480, such as e.g. a central server arrangement. There may also be more than one processing device 140, where e.g. one local processing device is located in the portable electronic device 120 and one central processing device is located in a central electronic arrangement 480. The local processing device may then e.g. process the sound received by the microphone 125 and filter out only the sound received with the highest amplitude by the microphone 125. Information about this sound may then be transmitted from the local processing device to the central processing device, which determines the position of the portable electronic device 120. It is then advantageous if the data storage 130 is also comprised in the central electronic arrangement 480.

Figure 5 schematically illustrates a method 500 for determining a position of a portable electronic device. The method 500 may comprise: Step 510: emitting a different unique sound signature from each of a plurality of sound emitting devices.

Step 520: storing information regarding which sound emitting device emits which unique sound signature, and the position of each sound emitting device, in a data storage.

Step 530: receiving sound emitted by at least one sound emitting device in a sound receiving device, such as a microphone, comprised in a portable electronic device.

Step 540: determining, based on sound received by the sound receiving device and information stored in the data storage, a position of the portable electronic device.

Step 560: transmitting entrance granting information to a first entrance granting arrangement, such as a door unlocking and/or opening arrangement, if the sound received by the sound receiving device corresponds to the unique sound signature emitted by a first sound emitting device of the plurality of sound emitting devices positioned in the vicinity of said first entrance granting arrangement.

The method 500 may further comprise one or more of: Step 550: transmitting information about the sound received by the sound receiving device to a central electronic arrangement, such as e.g. a central server arrangement, wherein the position of the portable electronic device is determined in said central electronic arrangement.

Step 570: filtering out the sound received with the highest amplitude by the sound receiving device, and basing the determination of the position of the portable electronic device on only this sound.

In embodiments, the entrance granting information, e.g. in the form of a QR code, is transmitted from the portable electronic device to the first entrance granting arrangement.

In embodiments, the entrance granting information, e.g. in the form of a QR code, is transmitted from the central electronic arrangement to the portable electronic device.

In embodiments, the entrance granting information is transmitted from the central electronic arrangement to the first entrance granting arrangement.

In embodiments, the unique sound signature is a sound of a specific frequency, ora sound where different specific frequencies follow each other according to a pattern.

In embodiments, the unique sound signature consists of frequencies from 16 kHz to 96 kHz.

In embodiments, the portable electronic device is a mobile phone, such as e.g. a smartphone.

The disclosed system 100 and method 500 provide a number of advantages in relation to known technology. For example, if WiFi or Bluetooth are to be used for communicating between a portable electronic device 120 and an entrance granting arrangement 470, the portable electronic device 120 and the entrance granting arrangement 470 first have to be paired with each other. No such pairing is required in order to use the disclosed system 100 and method 500. Further, if access cards or tags are to be used, the access cards/tags first have to be activated and connected to the system. In the disclosed system 100 and method 500, an account can be created for a user and then be accessed from different portable electronic devices 120 - the account does not have to be tied to a physical object such as an access card or a tag.

In systems where movement of a large number of users is tracked, the disclosed system 100 and method 500 provide the advantage of reducing the signal traffic compared to the use of e.g. WiFi or Bluetooth.

The foregoing disclosure is not intended to limit the present invention to the precise forms or particular fields of use disclosed. It is contemplated that various alternate embodiments and/or modifications to the present invention, whether explicitly described or implied herein, are possible in light of the disclosure. For example, the disclosure describes entrance granting information to be transmitted from a portable electronic device to an entrance granting arrangement in the form of a QR code displayed in a display of the portable electronic device and viewed by a camera in the entrance granting arrangement. However, entrance granting information may be transmitted from a portable electronic device to an entrance granting arrangement in any form and using any type of wireless means, such as e.g. Bluetooth or NFC. Accordingly, the scope of the invention is defined only by the claims.

Claims

1. System (100) for determining the position of a portable electronic device (120), comprising: a plurality of sound emitting devices (110, 210, 310, 410), each configured to emit a different unique sound signature; at least one data storage (130), configured to store information regarding: which sound emitting device (110, 210, 310, 410) emits which unique sound signature, and the position of each sound emitting device (110, 210, 310, 410); at least one portable electronic device (120) comprising a sound receiving device (125), such as e.g. a microphone, configured to receive sound emitted by the sound emitting devices (110, 210, 310, 410); and at least one processing device (140), configured to determine, based on sound received by the sound receiving device (125) and information stored in the data storage (130), a position of the portable electronic device (120), wherein a first sound emitting device (410) of the plurality of sound emitting devices (410) is positioned in the vicinity of a first entrance granting arrangement (470), such as a door unlocking and/or opening arrangement, and entrance granting information is transmitted to the first entrance granting arrangement (470) if the sound received by the sound receiving device (125) corresponds to the unique sound signature emitted by the first sound emitting device (410).

2. System (100) according to claim 1, wherein the entrance granting information, e.g. in the form of a QR code, is transmitted from the portable electronic device (125) to the first entrance granting arrangement (470).

3. System (100) according to claim 1, further comprising at least one central electronic arrangement (480), such as e.g. a central server arrangement, to which the at least one portable electronic device (120) is configured to transmit information about the sound received by the sound receiving device (125), wherein the at least one data storage (130) is comprised at least partly in the central electronic arrangement (480), and the determination of the position of the portable electronic device (120) takes place in the central electronic arrangement (480).

4. System (100) according to claims 2 and 3, wherein the central electronic arrangement (480) is configured to transmit the entrance granting information, e.g. in the form of a QR code, to the portable electronic device (120).

5. System (100) according to claim 3, wherein the entrance granting information is transmitted from the central electronic arrangement (480) to the first entrance granting arrangement (470).

6. System (100) according to any one of claims 1-5, wherein the unique sound signature is a sound of a specific frequency, or a sound where different specific frequencies follow each other according to a pattern.

7. System (100) according to any one of claims 1-6, wherein the unique sound signature consists of frequencies that are inaudible to human ears, such as e.g. frequencies from 16 kHz to 96 kHz.

8. System (100) according to any one of claims 1-7, wherein the at least one processing device (140) is configured to filter out the sound received with the highest amplitude by the sound receiving device (125), and base the determination of the position of the portable electronic device (120) on only this sound.

9. System (100) according to any one of claims 1-8, wherein the portable electronic device is a mobile phone, such as e.g. a smartphone.

10. Method (500) for determining the position of a portable electronic device, comprising: emitting (510) a different unique sound signature from each of a plurality of sound emitting devices; storing (520) information regarding which sound emitting device emits which unique sound signature, and the position of each sound emitting device, in a data storage; receiving (530) sound emitted by at least one sound emitting device in a sound receiving device, such as e.g. a microphone, comprised in a portable electronic device; and determining (540), based on sound received by the sound receiving device and information stored in the data storage, a position of the portable electronic device transmitting (560) entrance granting information to a first entrance granting arrangement, such as a door unlocking and/or opening arrangement, if the sound received by the sound receiving device corresponds to the unique sound signature emitted by a first sound emitting device of the plurality of sound emitting devices positioned in the vicinity of said first entrance granting arrangement.

11. Method (500) according to claim 10, wherein the entrance granting information, e.g. in the form of a QR code, is transmitted from the portable electronic device to the first entrance granting arrangement.

12. Method (500) according to claim 10, further comprising transmitting (550) information about the sound received by the sound receiving device to a central electronic arrangement, such as e.g. a central server arrangement, in which the determination of the position of the portable electronic device takes place.

13. Method (500) according to claims 11 and 12, wherein the entrance granting information, e.g. in the form of a QR code, is transmitted from the central electronic arrangement to the portable electronic device.

14. Method (500) according to claim 13, wherein the entrance granting information is transmitted from the central electronic arrangement to the first entrance granting arrangement.

15. Method (500) according to any one of claims 10-14, wherein the unique sound signature is a sound of a specific frequency, or a sound where different specific frequencies follow each other according to a pattern.

16. Method (500) according to any one of claims 10-15, wherein the unique sound signature consists of frequencies that are inaudible to human ears, such as e.g. frequencies from 16 kHz to 96 kHz.

17. Method (500) according to anyone of claims 10-16, further comprising filtering out (570) the sound received with the highest amplitude by the sound receiving device, and basing the determination of the position of the portable electronic device on only this sound.

18. Method (500) according to anyone of claims 10-17, wherein the portable electronic device is a mobile phone, such as e.g. a smartphone.