JP2012205119A - Communication control device, program and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable stable and efficient handover of a large amount of information without making a communication channel and a subordinate device uselessly fall into a congestion condition or an overload condition, in regard to a communication control device which determines the information handed over from the communication channel to be information to be handed over to a different communication channel or the subordinate device, a program which makes a computer function as such a communication control device, and a recording medium in which the program is recorded.SOLUTION: The communication control device determines the information handed over from a first communication channel to be information to be handed over to a second communication channel or the subordinate device. The communication control device includes: priority identification means for identifying individual priority of the information handed over from the first communication channel; and control means for determining the information handed over from the first communication channel to be the information to be handed over to the second communication channel or the subordinate device, with the priority identified by the priority identification means.

Description

  The present invention relates to a communication control apparatus that uses information delivered from a communication path as information delivered to a different communication path or a subordinate apparatus, a program for causing a computer to function as such a communication control apparatus, and the program recorded therein. And a storage medium.

  In recent years, devices (hereinafter simply referred to as “terminal devices”) that transmit information as wireless signals of information provided by various sensors have been reduced in price, size, and weight, and can be easily operated for a long time with a battery. Since it can be realized, it is being applied to collect a large amount of diverse information on people and vehicles that are scattered geographically.

  Such a terminal device is carried by, for example, 30,000 or more runners participating in a city marathon, and is used for collecting and monitoring biological information such as individual heart rate and body temperature of these runners.

  In addition, there existed patent document 1 thru | or patent document 4 listed below as a prior art relevant to this invention.

(1) “A wireless base station that constitutes a wireless communication network in which a plurality of wireless base stations are connected to each other wirelessly, and temporarily stores information received from at least one of the other wireless base stations and subordinate terminals. To calculate the link cost according to the buffer cost, the node cost according to the degree of congestion of the own station, and the radio state of the link, and to generate cost information that takes into account the node cost and the link cost, based on the cost information A path control information processing unit for determining a communication path and a path control unit for designating a transfer destination of data stored in the buffer according to the determined communication path. And wireless base station characterized in that it enables path control considering both wireless network efficiency.

(2) “In a wireless packet communication system composed of a plurality of radio base stations and one or more radio terminals, one specific radio base station (root station) among the plurality of radio base stations is a starting point. A packet B that forms a tree-shaped communication path and is transmitted and received between the wireless base stations via the tree-shaped communication path includes a transmission source address including a MAC address of the transmission source wireless terminal in a header portion, a destination wireless terminal A destination address including the MAC address, a transmitting station address including the MAC address of the transfer source radio base station that transmits the packet, a receiving station address including a MAC address of the transfer destination radio base station that receives the packet, Each of the plurality of radio base stations registers an attribute table for registering radio terminals belonging to the own station and radio base stations that can be relayed based on the tree-shaped communication path. A relay radio base station table; and an address table that registers a destination radio terminal (destination address) and a transfer destination radio base station (reception station address) in association with each other, and each radio base station receives the packet B The transmission source wireless terminal indicated by the transmission source address is associated with the transfer source wireless base station indicated by the transmission station address, and the destination wireless terminal (destination address) and the transfer destination wireless base station (reception station address) are associated with each other. If the destination wireless terminal indicated by the destination address is registered in the attribution table, the packet is transmitted to the destination wireless terminal, and the destination wireless terminal indicated by the destination address is registered in the attribution table. If it is not registered in the address table and registered in the address table, the packet B is transmitted to the transfer destination radio base station corresponding to the destination radio terminal. A radio base station that is not registered in the attribution table and the address table and that can be relayed to other than the transfer source radio base station that has transmitted the packet B is entered in the relay radio base station table. If registered, the packet B is sequentially transmitted to all relayable radio base stations, and the destination wireless terminal indicated by the destination address is not registered in the attribution table and the address table, and further transmits the packet B If a radio base station that can relay to other than the transfer source radio base station is not registered in the relay radio base station table, the packet B is discarded, thereby increasing the device size and power consumption of the radio base station. "Learning type that is characterized by the fact that packet transfer can be performed without accompanying, and the radio base station can easily determine the appropriate radio base station to transfer next" Line packet transfer method ... Patent Document 2

(3) “A wireless packet transfer method in a wireless packet communication network including a plurality of wireless base stations constituting a tree-shaped transfer path with a specific wireless base station as a root station and wireless terminals belonging to each wireless base station. In each wireless base station, a packet transferred on the tree-shaped transfer path in a direction approaching the own station is monitored, and the wireless terminal indicated by the transmission source address of the packet and the wireless base indicated by the transmission station address When a packet is received from the wireless base station on the tree-shaped transfer path located in the opposite direction to the root station when viewed from the wireless terminal belonging to the local station or the local station The wireless base station associated with the destination wireless terminal is defined as a transfer destination on condition that the destination wireless terminal indicated by the destination address of the packet is registered in the table. A packet transmitted to the radio base station selected as the transfer destination by shortcutting the tree-shaped transfer path, and transmitted from the other radio base station by shortcuting the tree-shaped transfer path , The wireless base station on the tree-shaped transfer path that is located in the same direction as the root station when viewed from the local station is not selected as a transfer destination. A wireless packet transfer method characterized in that a packet can be transferred without passing through and a reduction in throughput is prevented.

(4) “Choose one of the other wireless bridges within the communicable range that has a communication quality of a predetermined level or higher and make it the target of the Spanning Tree Protocol (STP), and broadcast to multiple wireless bridges. A wireless bridge characterized by "improving message transfer efficiency" by adding a MAC header with a broadcast or multicast address as a relay destination address to a packet to be transmitted and sending it as a broadcast packet from the wireless interface " ... Patent Document 4

JP 2005-303827 A JP 2000-069046 A JP 2000-078147 A JP 2003-188811 A

  By the way, regarding the biometric information of individual runners wirelessly transmitted from the terminal device described above, when the number of runners is as large as 30,000 or more, the following (1), (2) It was difficult to collect and monitor.

(1) If limited resources such as radio frequencies are additionally occupied in a specific area or time zone in which a city marathon is conducted, there will be significant pressure on normal communication traffic allocated on the frequency axis, etc. There is a possibility of causing a congestion state.

  As for such traffic compression and congestion, for example, in the form shown in any of the following items a) and b), it is possible to reduce the service area where traffic is unevenly distributed and to reuse the frequency. By doing so, avoidance or significant reduction can be achieved.

a) The radio information of each runner that is not overlapped with each other and transmitted wirelessly through a wireless zone to which a common radio frequency (radio channel) is assigned is a plurality of radios arranged along the course of the city marathon. It is collected by the base station and delivered to a higher-level ground station (delivering these biometric information to emergency supervisors such as doctors and rescue workers).

b) The biometric information of each runner overlapped with each other on the course and transmitted wirelessly through the wireless zone formed by reusing the wireless frequency is collected by the plurality of wireless base stations and Delivered to the ground station.

  However, in the configuration shown in the above item a), a radio base station in which a large number of runners are concentrated in the vicinity is based on a large amount of biological information transmitted from terminal devices carried by these operators when handed over to a higher-level ground station. There was a high possibility that the total transmission efficiency of urgent biological information would be significantly reduced due to the congestion.

  In the configuration shown in the above item b), the terminal device carried by a runner located at a point where a plurality of radio zones overlap each other along the marathon course is applied frequency arrangement, channel arrangement, multiple access method, etc. In some cases, since biometric information is wirelessly transmitted through these wireless zones, the amount of information delivered to the ground station and the amount of processing required for that ground station increase. There was a high possibility that the responsiveness would decrease.

(2) Even if a radio transmission path that occupies finite resources such as radio frequencies and has a sufficient transmission rate for the transmission of a large amount of biological information is secured, the biological information is managed at the management center that should manage the biological information. Among them, it has not been easy to provide emergency supervisors such as doctors and rescuers with a limited number of people by preferentially extracting biometric information that requires emergency.

  The present invention provides a communication control device, a program, and a recording medium capable of realizing stable and efficient delivery of a large amount of information without causing a communication path or a subordinate device to be unnecessarily congested or overloaded. Objective.

  In the present invention, in the communication control device that uses the information delivered from the first communication channel as information to be delivered to the second communication channel or a subordinate device, the priority identification means is delivered from the first communication channel. Identifies the individual priority of the information provided. The control means uses the information delivered from the first communication path as information to be delivered to the second communication path or the subordinate apparatus with the priority identified by the priority identifying means.

  That is, the information delivered from the first communication path is delivered to the second communication path or the subordinate apparatus with each priority.

  In the present invention, the priority identifying unit is configured to individually identify the information transferred from the first communication path based on a knowledge base in which knowledge suitable for information that can be transferred from the first communication path is registered in advance. Identify the priority of.

  In other words, the criteria for preferential allocation of the transmission bandwidth of the second communication path and the processing amount of the devices under its control are priorities that are consistent with the problem to be solved based on the information to which these transmission bandwidths and throughput are allocated. As given.

  In the present invention, the control means delivers the process based on the knowledge registered in the knowledge base to the information delivered from the first communication path, thereby delivering the information to the second communication path or the subordinate apparatus. Generate the information that should be done.

  In other words, information to be handed over to the second communication path or the subordinate device is obtained by performing processing suitable for the problem to be solved based on the information handed over from the first communication path. Generated.

  According to the present invention, the transmission band of the second communication path or the processing amount of the subordinate apparatus is preferentially assigned to information having a high priority, and the transmission band or processing is assigned to such low priority information. A congestion state or an overload state due to an unnecessarily allocated amount is reliably and stably avoided.

  Alternatively, the present invention can flexibly adapt to various problems to be solved in the system to which the present invention is applied.

  Therefore, in the system to which the present invention is applied, the responsiveness and reliability are stably maintained high, and the performance and added value are comprehensively enhanced.

It is a figure which shows one Embodiment of this invention. It is an operation | movement flowchart of the data storage server in this embodiment. It is an operation | movement flowchart of the ground station in this embodiment. It is a figure which shows the cooperation of each part in this embodiment. It is a figure which shows the structure of biometric information. It is a figure which shows the structure of a knowledge base.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing an embodiment of the present invention.

  In the figure, a terminal 11s operated by an emergency supervisor and a terminal 11mo operated by a person who operates and maintains the present embodiment are connected to the ground station 20 (via a predetermined communication path). . The ground station 20 individually forms a radio transmission path (hereinafter referred to as “upper radio transmission path”) with the subordinate data storage servers 30-1 to 30-p. The data storage server 30-1 is individually connected to radio base stations 40-11 to 40-1q that form radio zones 40z-11 to 40z-1q along the marathon course. "Wireless transmission path").

  For example, when the wireless zones 40z-11 to 40z-1q are configured as cells having a radius of 100 meters or less, a 2.4 GHz band such as a wireless LAN (WiFi), Bluetooth, ZigBee, or the like is applied. If the wireless zone is to be configured as a wireless zone having a radius of 100 meters or more, the wireless system may be formed as a specific low power radio to which a 400 MHz band is applied or a wireless system such as WiMax.

  In addition, with regard to the above-described upper wireless transmission path, when a large amount of traffic generated by a large number of runners and citizens concentrating on a specific area along the marathon course should be avoided from being concentrated on the public network. May be formed as a public broadband mobile communication system.

  In the following, the data storage servers 30-2 to 30-p and the configuration under the data storage server 30-2 to 30-p are the same as the data storage server 30-1, so “2” to “p” are assigned instead of “1”, and detailed description thereof is omitted here.

FIG. 2 is an operation flowchart of the data storage server in the present embodiment.
FIG. 3 is an operation flowchart of the ground station in the present embodiment.
FIG. 4 is a diagram showing the linkage of each part in the present embodiment.

  Hereinafter, with reference to FIG. 1 thru | or FIG. 4, cooperation and operation | movement of each part for this embodiment to function as a "remote healthcare system" are demonstrated.

The feature of the present invention lies in the form of communication control performed in the present embodiment as will be described later by linking the data storage servers 30-2 to 30-p and the ground station 20.
In the following, for items common to the data storage servers 30-1 to 30-p and the components under them, any one of “1” to “p” is assigned as the first serial number of the corresponding component. Is also described by adding a subscript “c” indicating that it may be applicable.

  The data storage server 30-c controls these wireless base stations 40-c1 to 40-cq under the control of the ground station 20 (or autonomously) via lower wireless transmission paths. Radio zones 40z-c1 to 40z-cq that overlap with each other along the marathon course and are allocated by reuse are formed under 40-c1 to 40-cq (step S1 in FIG. 2).

  A terminal device carried by a runner traveling along such a marathon course has a radio zone (hereinafter referred to as a “current radio zone”) 40z- in which the terminal is located among the radio zones 40z-c1 to 40z-cq. Predetermined biological information is transmitted to the radio base station 40-cC forming the cC.

For example, as shown in FIG. 5, such biological information is transmitted as a packet configured as a sequence of fields in which the following items are respectively arranged.
(1) “ID”, which is a unique identifier assigned to the source terminal (and destination ground station pair)

(2) Unique “data type” indicating any one or a combination of body temperature, pulse, blood pressure, etc. included in the corresponding biological information
(3) “Data” in which any one or a combination of body temperature, pulse, blood pressure,.

  The radio base station 40-cC wirelessly transmits the corresponding biological information to the data storage server 30-c located above the radio base station 40-cC via the lower radio transmission path (FIG. 4 (1)).

  In a predetermined storage area of the main storage (or external storage) of the data storage server 30-c, as shown in FIG. 6, a knowledge base 30ib-c configured as a set of records packed with the following items is arranged. Is done.

(1) "Data type" that is a key for search based on "data type" of description that can be included in biometric information
(2) "Processing form" configured as a pair of columns of processing form to be applied to biological information including the "data type" and parameters to be applied in the processing

(3) "Priority" given in advance to biometric information including the above "data type" and defined as a function to be described later
When the data storage server 30-c identifies the biometric information (hereinafter referred to as “corresponding biometric information”) wirelessly transmitted from the radio base station 40-cC via the lower radio transmission as described above, the data storage server 30-c performs the following processing. Perform (FIG. 4 (2)).

(1) The “data type” included in the corresponding biometric information is extracted, and the corresponding record (hereinafter referred to as “specific record”) on the knowledge base 30ib-c is specified using the “data type” as a search key (hereinafter referred to as “specific record”) ( FIG. 2 step S2, FIG. 4 (2)).

(2) The priority P given as a function of body temperature, pulse, blood pressure,... Defined in the “specific record” and packed in the data field of “corresponding biometric information” is calculated. It is determined whether or not the specified threshold value th is exceeded (step S3 in FIG. 2, FIG. 4 (3)).

(3) When the priority P exceeds the threshold th, the following processes (3-1) to (3-3) are performed.
(3-1) “Biometric information r” is generated by applying “processing form” included in the “specific record” to the “biometric information” (step S4 in FIG. 2, FIG. 4 (4))) .

(3-2) Generate “biological information t” by reflecting the “biological information r” on the “data” included in “corresponding biological information” (including replacing the contents of “data field”). (Step S5 in FIG. 2, FIG. 4 (5)).

(3-3) The “biological information t” is wirelessly transmitted to the ground station 20 via the higher-order wireless transmission path (step S6 in FIG. 2, FIG. 4 (6)).
(4) Regardless of whether or not the priority P exceeds the threshold th, “corresponding biometric information” is logged (step S7 in FIG. 2).

  On the other hand, as described above, the ground station 20 analyzes the “biological information t” delivered from the data storage server 30-c via the upper wireless transmission path (step S1, FIG. 4 (8) in FIG. 3), Based on the result of the analysis, the corresponding “biological information t” is delivered to either or both of the terminal 11s and the terminal 11mo (step S2 in FIG. 3, FIG. 4 (9)).

  That is, the biological information transmitted from the terminal device located in any of the radio zones 40z-11 to 40z-1q,..., 40z-p1 to 40z-pq is also parallel to such biological information from a large number of terminal information. Even when transmitted, the radio base stations 40z-11 to 40z-1q,..., 40z-p1 to 40z-pq and the data storage servers 30-1 to 30-p are listed as follows. Under the cooperation, the finite radio frequency and the processing amount of the data storage servers 30-1 to 30-p and the ground station 20 are effectively utilized, so that the higher the degree of urgency, the faster the terminal terminal 11s and the terminal 11mo And is subject to prompt and smooth action.

(1) The radio zones 40z-11 to 40z-1q, ..., 40z-p1 to 40z-pq are formed along the marathon course under the reuse of radio frequencies, so that the data storage server 30-c can be quickly To be handed over.
(2) The transmission band of the higher-order wireless transmission path is preferentially assigned to the biometric information t identified as having high priority by the data storage server 30-c.

  Therefore, according to the present embodiment, the preferential allocation of the transmission band, the processing amount, and other resources is automatically and inexpensively performed on the biometric information of the runner in a situation that requires immediate handling. Even if the total number is extremely large, the biometric information of these runners is collected and managed effectively, and activities such as organizers of the city marathon and related parties such as emergency vehicle arrangements should be performed. Cooperation support is realized smoothly.

  In this embodiment, the data storage server 30-c is provided with the knowledge base 30ib-c. However, such a data storage server 30-c is connected to the ground station 20 by the data storage server 30-c, for example. When the “biological information t” to be delivered is always the same as the “corresponding biological information” described above, it is a database that simply gives the priority P corresponding to the “data type” included in the “biological information” It may be replaced.

  In the present embodiment, the content and format of the knowledge base 30ib-c and the database provided in place thereof, and the processing procedure performed by the data storage server 30-c are equal to the processing described above. Any result may be used as long as the result is obtained.

  Further, in the present embodiment, the above-described terminals 11 s and 11 mo are provided as peripheral devices of the ground station 20.

  However, these terminals 11s and 11mo may be terminals connected to a specific communication port of the ground station 20 and arranged on the same or different communication path as the above-described higher-order wireless transmission path.

  Further, in the present embodiment, the ground station 20, for example, “biological information to be delivered to the terminals 11 s and 11 mo among the“ biological information t ”delivered from the data storage server 30-c via the upper wireless transmission path. When the priority of the information “t” is to be imposed, the processing performed by the data storage server 30-c, which includes the aforementioned knowledge base 30ib-c or a database replacing the knowledge base 30ib-c, and Similar processing may be performed.

Further, in the present embodiment, the radio base stations 40-c1 to 40-cq under the control of the data storage server 30-c
Thus, wireless zones 40z-c1 to 40z-cq are formed, respectively.

  However, the present invention is not limited to such a configuration, and if the transmission capacity of the lower wireless transmission path is large enough that wireless transmission of a large amount of “biological information” to the data storage server 30-c is not impaired, The number p of the storage servers 30-1 to 30-p and the number q of the wireless base stations 40-c1 to 40-cq that individually form wireless zones under the data storage server 30-c are any values. May be.

  Further, in the present embodiment, the “corresponding biometric information” logged by the data storage server 30-c is not particularly processed.

  However, with respect to the “corresponding biological information” logged in this way, for example, the data storage server 30-c, the ground station 20, and an external computer alone perform processing, or at least two of these are linked. Under function distribution or load distribution, it may be utilized to realize the items listed below.

(1) Understanding the situation related to the smooth and efficient holding of city marathons, as well as early prediction and response of possible situations
(2) Identify various improvements related to the next and subsequent events

(3) Support for the following activities and linkages to be performed by organizers and related parties in the area of the wireless zone 40z-cC where the terminal device that is the source of the “corresponding biometric information” was located:
(3-1) “Broadcasts that encourage hydration” to be conducted on a regional basis, taking into account the overall trend of “biological information” and climate information
(3-2) Arrangement of organizers and related parties according to the distribution of the number of runners (terminal devices) individually located in the radio zones 40z-11 to 40z-1q, ..., 40z-p1 to 40z-pq Optimization

  Furthermore, in the present embodiment, both the lower wireless transmission path and the upper wireless transmission path are applied if transmission of “biological information” is achieved with sufficient efficiency at a desired transmission quality and transmission speed. Any frequency arrangement, channel arrangement, multiple access method, modulation / demodulation method, and the like may be used.

  In addition, the content and format of the biological information to be wirelessly transmitted via the lower wireless transmission path and the upper wireless transmission path may be any as long as they are compatible with these wireless transmission path systems.

  Furthermore, in the present embodiment, the processing performed by the data storage server 30-c and the ground station 20 for delivering the “biological information” may be realized as processing in any communication layer.

  In the present embodiment, the above-described communication control performed in the ground station 20 and the data storage server 30-c may not be realized by software executed by a general-purpose computer or server. It may be realized only by hardware, or may be realized in cooperation with hardware and software (the presence or absence and form of function distribution or load distribution is unquestioned).

  Furthermore, the present invention is not limited to a remote health care system in a city marathon. For example, a place where renewable energy is generated for each region in order to reduce the environmental load by strengthening regional bonds. A lot of information, such as local production and local consumption of renewable energy by collecting, monitoring, and utilizing a lot of information output by sensors installed in places where energy is consumed in each region If the information that is notified asynchronously from the source is a system that should be subjected to suitable processing with high accuracy and no delay, the configuration of the communication system included in the system (including various methods such as the topology of the communication path) It is equally applicable regardless of.

In the present embodiment, information transmitted through the lower wireless transmission path and the upper wireless transmission path is only biometric information.
However, the information transmitted in this way is not limited to biometric information, and may be any information as listed below, for example.

(1) Emergency information, etc. notified from the terminal device according to the operation performed by the runner on the terminal device
(2) Information that is generated by a processor incorporated in a terminal device and that does not reflect any information given by a sensor such as a biosensor and the above operation

Further, in the present embodiment, a two-layer communication system is configured under the ground station 20 via an upper radio transmission path and a lower radio transmission path.
However, in the present invention, the number of such layers may be “1” or “3” or more, and any of the communication paths formed between these layers is not limited to the wireless transmission path, for example, Alternatively, it may be formed as a wired transmission line or an optical transmission line.

  In this embodiment, the data storage server 30-c and the ground station 20 are different in configuration. However, the data storage server 30-c and the ground station 20 have hardware that can function as both, It may be standardized as a combination with software that realizes the above-described communication control by being executed by a processor that makes full use of the wear.

  Further, the present invention is not limited to the above-described embodiments, and various configurations can be made within the scope of the present invention, and any improvement may be applied to all or some of the components.

  Hereinafter, among the inventions disclosed in the present application, the configurations, operations, and effects of the invention that were not described in the “Claims” will be described as “Claims”, “Means for Solving the Problems”, List them in a format similar to the description in the “Effect” column.

[Claim 6] In the communication control apparatus according to any one of claims 1 to 3,
A communication control apparatus comprising storage means for storing information delivered from the first communication path.

  In the communication control device having such a configuration, in the communication control device according to any one of claims 1 to 3, the storage unit stores information delivered from the first communication path.

  That is, even if the information delivered from the first communication path is excluded from the target of delivery to the second communication path or the subordinate apparatus due to low priority, or the delivery is greatly delayed It is preserved as a target of desired processing that can be performed in the system to which the present invention is applied.

  Therefore, even if the information delivered from the first communication channel is not delivered to the second communication channel or the subordinate device, it can be effectively used. And performance is improved.

[Claim 7] In the communication control apparatus according to claim 6,
A communication control apparatus comprising: adaptive processing means for performing predetermined processing on the information stored by the storage means.

  In the communication control device having such a configuration, in the communication control device according to claim 6, the adaptive processing means performs predetermined processing on the information stored by the storage means.

  That is, even if the information delivered from the first communication path is information that is excluded from the delivery target to the second communication path or the subordinate apparatus because of low priority, or the delivery is greatly delayed. Various processes are preferably performed in a system to which the present invention is applied.

  Therefore, even information that has not been delivered to the second communication path or the subordinate apparatus among the information delivered from the first communication path is effectively utilized.

11mo, 11s terminal 20 ground station 30 data storage server 30ib knowledge base 40 radio base station 40z radio zone

Claims (5)

A communication control device that uses the information delivered from the first communication path as information to be delivered to the second communication path or a subordinate device,
Priority identification means for identifying individual priorities of information delivered from the first communication path;
Control means for setting information delivered from the first communication path as information to be delivered to the second communication path or the subordinate apparatus with the priority identified by the priority identification means. A communication control device. The communication control device according to claim 1,
The priority identifying means includes
Knowledge suitable for information that can be delivered from the first communication path is identified based on a previously registered knowledge base, and individual priorities of information delivered from the first communication path are identified. Communication control device. The communication control device according to claim 2,
The control means includes
The information to be delivered to the second communication path or the subordinate apparatus is generated by performing processing based on the knowledge registered in the knowledge base on the information delivered from the first communication path. Communication control device.   The program which makes a computer function as a communication control apparatus of any one of Claims 1 thru | or 3.   A computer-readable storage medium storing a program for causing a computer to function as the communication control device according to any one of claims 1 to 3.