JP2019220750A - Electromagnetic wave suppressing device and electromagnetic wave suppressing method - Google Patents

Abstract

To provide a device and a method that prevent a mobile terminal from having adverse effects, such as malfunction, on apparatuses, systems, and the like situated around the mobile terminal.SOLUTION: An electromagnetic wave suppressing device 1 is an electromagnetic wave suppressing device for suppressing electromagnetic waves emitted from a mobile terminal and includes: a shielding section 2 that electromagnetically shields a closed space containing a mobile terminal PT from the outside of the closed space; a pseudo base station 3 that is provided inside the closed space, communicates with the mobile terminal PT contained in the closed space, but does not communicate with objects outside the closed space.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a technique for suppressing electromagnetic waves emitted from a mobile terminal such as a mobile phone.

  Until now, as shown in Patent Literatures 1 to 3 below, in order to prevent radio waves emitted from a mobile phone from affecting performances performed by people or facilities using a cardiac pacemaker or the like, Various devices and systems have been devised.

JP-A-2003-08490 JP-A-11-88300 JP-A-2002-84226

  However, in the above-described apparatus and system, since strong jamming radio waves are used to hinder the operation of the mobile phone, there is a problem that a malfunction or a stoppage of the whole apparatus is caused in a medical device, a measuring device, and the like. .

  The present invention has been made in order to solve such a problem, and an object of the present invention is to provide an apparatus and a method for preventing a device or a system located around a mobile terminal from causing an adverse effect such as a malfunction. .

  In order to solve the above problems, the present invention is an electromagnetic wave suppression device for suppressing electromagnetic waves emitted from a portable terminal, and shielding means for electromagnetically shielding a closed space including the portable terminal from outside the closed space. , An electromagnetic wave suppression device provided with a pseudo base station that is provided in the closed space and communicates with a portable terminal included in the closed space, but does not perform communication with an external object. .

  According to another aspect of the present invention, there is provided an electromagnetic wave suppression method for suppressing an electromagnetic wave emitted from a mobile terminal, comprising: electromagnetically shielding a closed space including the mobile terminal from outside the closed space. And providing a pseudo base station in the closed space that communicates with a portable terminal included in the closed space but does not perform communication with an external object in the closed space. I do.

  ADVANTAGE OF THE INVENTION According to this invention, the apparatus and method which do not produce a bad influence, such as a malfunction, on the apparatus, system, etc. which are located around a portable terminal can be obtained.

FIG. 1A is a graph showing the intensity (measured value) of a radio wave emitted from a mobile phone, and FIG. 1A shows a case where the mobile phone is placed in a closed space completely electromagnetically shielded from the outside. FIG. 1B shows a reception state in which three antennas are displayed on the monitor of the mobile phone, and FIG. 1C shows a reception state in which one antenna is displayed on the monitor of the mobile phone. This shows the measured radio field intensity in a certain case. It is a block diagram showing composition of electromagnetic wave suppression device 1 concerning an embodiment of the invention. It is a flowchart which shows the electromagnetic wave suppression method concerning embodiment of this invention. FIG. 3 is a diagram for explaining the intensity of radio waves emitted by the pseudo base station 3 shown in FIG. 2. FIG. 3 is a diagram for explaining an operation of the pseudo base station 3 shown in FIG. 2.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.

  First, the communication operation by the mobile phone will be described. FIG. 1 is a graph showing the intensity (measured value) of a radio wave emitted from a mobile phone. FIG. 1 (a) shows a mobile phone in a closed space completely shielded electromagnetically from the outside. FIG. 1B shows a state where three antennas are displayed on the monitor of the mobile phone when placed, and FIG. 1C shows one antenna displayed on the monitor of the mobile phone. This shows the actually measured radio field intensity in the case of the receiving state.

  It is known that a mobile phone adjusts the intensity (power) of an output radio wave according to the intensity of a received radio wave. Specifically, the transmission power of the mobile phone increases as the distance from the base station increases, and the strongest radio wave in a state immediately before a state where the radio wave does not reach the so-called “out-of-service area” (hereinafter referred to as “out-of-service mode”). Send

  Then, in the out-of-service mode, the mobile phone emits such a strong radio wave while trying to notify the base station of its own existence, so that the power consumption increases and the built-in battery is quickly consumed.

  On the other hand, when the mobile phone is placed in a closed space such as a room completely electromagnetically shielded from the outside, the mobile phone is in a so-called out-of-service mode, but is shown in FIG. As described above, no radio wave is emitted because communication with a base station outside the closed space is not possible. In the out-of-service mode, the mobile phone repeatedly performs an operation of increasing the reception sensitivity and searching for a radio wave emitted from the base station, so that the power consumption increases and the built-in battery is quickly consumed.

  However, if you look at a general shielded room, the room may be opened or closed, the room may have windows or vents, or information lines and power lines may be connected to the outside of the room. Often, unexpectedly, complete shielding is not achieved. Further, in a building such as reinforced concrete, there are often places where radio waves transmitted from a base station are difficult to arrive.

  Therefore, when placed in these places, the mobile phone erroneously recognizes that the base station is distant, and transmits a radio wave with an intensity higher than usual in order to stabilize communication with the base station.

  Here, comparing FIG. 1 (b) and FIG. 1 (c), the reception status where only one antenna is displayed is better than the case where the reception status where three antennas are displayed on the monitor of the mobile phone is better. It can be seen that the radio wave intensity output from the mobile phone can be increased by a factor of 100 or more in the case of the above.

  Therefore, in the vicinity of instruments such as measuring instruments and medical instruments installed in a shielded room in order to avoid strong electromagnetic waves and conductive wires connected to these instruments, a mobile phone shown in FIG. Such a strong radio wave may be transmitted.

  At this time, due to the influence of the radio waves, malfunctions may be caused in the above-described measuring instruments, medical devices, and the like, or the entire system to which these devices are connected may stop without being limited thereto. Furthermore, since there is usually a possibility that a plurality of operators and visitors may be present in a facility or the like in which the above-described equipment is installed, a portable terminal such as a mobile phone that can be a dangerous electromagnetic wave source as described above is one. There is not always only one.

  In order to prevent such a situation, jamming radio waves (jamming) have been used so far, but jamming is so strong that it can overwrite a signal emitted from a base station and prevent the mobile terminal from decoding the signal. Because it is an electromagnetic wave, it is not suitable for use in an environment where such strong electromagnetic waves should be avoided. Therefore, the following electromagnetic wave suppression device and electromagnetic wave suppression method according to the embodiment of the present invention are useful.

  FIG. 2 is a block diagram illustrating a configuration of the electromagnetic wave suppression device 1 according to the embodiment of the present invention. As shown in FIG. 2, the electromagnetic wave suppression device 1 is an electromagnetic wave suppression device for suppressing electromagnetic waves emitted from a portable terminal such as a mobile phone, and a closed space including the portable terminal PT is provided from outside the closed space. A shielding unit 2 that is electromagnetically shielded; a pseudo base station 3 that is provided in the closed space and communicates with the portable terminal PT, but does not communicate with an external object; While surrounding the outside, the pseudo base station 3 is separated from the shielding unit 2, and an insulating structure, such as a reinforced plastic bar 4, for electrically insulating the closed space from the outside, and the pseudo base station 3 and the shielding unit 2 are grounded. A noise filter (NF) that is provided on the ground line 6 and the ground line 6 that connects the pseudo base station 3 and the shielding unit 2 and that removes noise that enters the closed space from outside the closed space through the ground line 6. 8 is provided.

  The reinforced plastic streaks 4 and the noise filter 8 reliably cut off conduction noise (signal) that penetrates through the shield 2 and the ground wire 6 due to a base station, an electromagnetic field generator, or the like that is located outside the building. Prepared for. As a result, for example, conduction noise is intentionally flown from the outside as base station information by a malicious person, and as a result, the indoor portable terminal PT is put into a call state, and radio waves are transmitted from a large number of indoor portable terminals PT. The situation of being transmitted can be avoided.

  FIG. 3 is a flowchart showing an electromagnetic wave suppression method according to the embodiment of the present invention. As shown in FIG. 3, in the electromagnetic wave suppression method according to the embodiment of the present invention, in step S1, a closed space including a portable terminal PT such as a mobile phone is electromagnetically shielded from outside the closed space.

  Here, specifically, for example, as shown in FIG. 2, the shielding unit 2 is provided so as to surround a building or a room such as a laboratory or a hospital in which the above-described measuring device and medical equipment are installed.

  Next, in step S2, the pseudo base station 3 that communicates with the portable terminal PT included in the closed space but does not perform communication with the external object is provided in the closed space. That is, specifically, for example, the pseudo base station 3 is installed in the above-mentioned building or room.

  Since the pseudo base station 3 can recognize that the base station is sufficiently close to the portable terminal PT, the portable terminal PT transmits a radio wave with a large intensity to search for the base station as described above. Eliminates the need. As a result, the intensity of the radio wave transmitted from the portable terminal PT can be minimized.

  FIG. 4 is a diagram for explaining the intensity of radio waves emitted by the pseudo base station 3 shown in FIG. As shown in FIG. 4, the radio wave intensity (radio wave level) L2 for recognizing that the base station is close to the portable terminal PT is higher than the radio wave level L1 barely reaching the portable terminal PT from the base station. At this time, the radio wave level of the jamming is assumed to be strong belonging to a range R2 larger than the radio wave level L2, but the intensity of the radio wave transmitted by the pseudo base station 3 falls within the range R1 between the radio wave level L1 and the radio wave level L2. It belongs to the above and is weaker than the electromagnetic resistance of the above-mentioned measuring instruments and medical equipment.

  In addition, the pseudo base station 3 performs a pseudo reply to various requests from the portable terminal PT as if a legitimate base station is nearby, and the intensity of the radio wave output from the portable terminal PT is reduced. The portable terminal PT is continuously controlled so as not to become large.

  However, when the pseudo base station 3 receives the call information from the portable terminal PT, the pseudo base station 3 returns to the portable terminal PT a notification indicating that communication cannot be performed with an object outside the room. Since the pseudo base station 3 is located near the portable terminal PT, a weak radio wave is used for this reply.

  On the other hand, when the mobile terminal PT does not make a call, the mobile terminal PT continues to receive signals from the pseudo base station 3 in a state where power consumption is suppressed. Since the radio wave transmitted from the base station outside the shielding unit 2 does not reach the portable terminal PT due to the shielding effect of the shielding unit 2, no call is received to the portable terminal PT.

  By the way, generally, all wireless base stations transmit a local signal indicating the area to which they belong, and the mobile phone constantly receives the local signal. When the mobile phone detects that the mobile phone has moved to the area by receiving the area signal indicating the new area, the mobile phone sends the area before and after the movement to the home memory station 7 via the exchange 5 shown in FIG. Report.

  Therefore, as shown in FIG. 5, the pseudo base station 3 is similarly selected as the nearest new base station to be a communication partner in the portable terminal PT that has entered the shielding unit 2 shown in FIG. This is reported to the home memory station 7 via the pseudo base station 3 and the exchange 5, but the pseudo base station 3 discards this notification. From this, in the electromagnetic wave suppression device 1 according to the embodiment of the present invention, as shown in FIG. 5, communication between the pseudo base station 3 and the exchange 5 is not performed.

  As a result, the pseudo base station 3 does not perform communication with the exchange 5, so that the power consumption is greatly reduced as compared with a general wireless base station, and the pseudo base station 3 is also used in the portable terminal PT. Is located nearby, the intensity of the radio wave used for making the above report to the pseudo base station 3 is weak enough.

  As described above, according to the electromagnetic wave suppression device and the electromagnetic wave suppression method according to the embodiment of the present invention, the portable terminal PT such as a mobile phone is brought into, for example, an operating room of a laboratory, a hospital, or a control room of a nuclear power plant. Even if it has been lost, since the intensity of the electromagnetic wave output from the portable terminal PT can be suppressed, it is possible to prevent an adverse effect such as malfunction from occurring on the devices and systems disposed in the laboratory or the like. An electromagnetic environment can be established.

  Further, according to the electromagnetic wave suppression device and the electromagnetic wave suppression method according to the embodiment of the present invention, the mobile terminal PT does not need to increase the receiving sensitivity to search for the nearest base station, and therefore, the mobile terminal PT Power consumption can also be reduced.

  In the above, incomplete but electromagnetic shielding means such as a space surrounded by conductors such as airplanes and sites isolated from the outside in a reinforced structure building, It should be noted that there is no need to newly construct a shielding means for shielding, and it can be utilized as it is.

DESCRIPTION OF SYMBOLS 1 Electromagnetic wave suppression device 2 Shielding part 3 Pseudo base station 4 Reinforced plastic streaks 6 Ground wire 8 Noise filter (NF)

Claims (7)

An electromagnetic wave suppression device for suppressing electromagnetic waves emitted from a mobile terminal,
Shielding means for electromagnetically shielding the closed space including the mobile terminal from outside the closed space,
An electromagnetic wave suppression device comprising: a pseudo base station that is provided in the closed space and communicates with the mobile terminal included in the closed space, but does not perform communication with an external object.   The electromagnetic wave suppression device according to claim 1, wherein the pseudo base station, when receiving the call information from the mobile terminal, returns to the mobile terminal a notification indicating that communication with the external object is not possible. .   The electromagnetic wave suppression device according to claim 1, wherein the pseudo base station discards the notification when receiving from the portable terminal a notification that the pseudo base station has been selected as a new base station to be a communication partner. Insulating means provided to surround the shielding means and electrically insulating the closed space from the outside,
Grounding means for grounding the pseudo base station and the shielding means,
The electromagnetic wave suppression device according to claim 1, further comprising a noise removing unit that removes noise that enters the closed space through the grounding unit. An electromagnetic wave suppression method for suppressing electromagnetic waves emitted from a mobile terminal,
Electromagnetically shielding the closed space including the mobile terminal from outside the closed space,
Providing a pseudo base station in the closed space that communicates with the portable terminal included in the closed space but does not perform communication with the external object in the closed space.   5. The pseudo base station according to claim 4, wherein when receiving call information from the mobile terminal, the pseudo base station returns a notification to the mobile terminal indicating that communication with the external object is not possible. Electromagnetic wave suppression method. The electromagnetic wave suppression according to claim 4, wherein the pseudo base station discards the notification when receiving from the portable terminal a notification that the pseudo base station has been selected as a new base station to be a communication partner. Method.

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