JP5377592B2 - Wireless communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the effect of leaked electric waves from a wireless base station on a leaky transmission path, thereby contributing to achievement of an elongated communication area. <P>SOLUTION: There is provided a wireless communication system using a leaky transmission path, comprising: a wireless base station 10; a leaky transmission path 20 connected to an antenna terminal 12 of the wireless base station 10 directly or via a coaxial cable and linearly arranged so as to form an elongated communication area; and a shield body 15 or an electric wave absorber provided so as to surround the wireless base station 10 other than a direction in which the leaky transmission path 20 is arranged. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  Embodiments described herein relate generally to a wireless communication system using a leaky transmission path.

  Conventionally, a wireless communication system using a leaky coaxial cable (LCX cable) is arranged such that an LCX cable connected to an antenna terminal of a wireless base station is arranged in a tunnel or factory at a length of several tens to several hundreds of meters or more. A long and narrow communicable area is created. In this case, even if there is leakage of radio waves from the radio base station, the leakage of radio waves from the radio base station is attenuated if it is several tens of meters away from the radio base station. For this reason, the influence of leakage of radio waves from the radio base station on the entire system is small.

  On the other hand, recently, as a use in a narrow range such as a conference room or a table, a simple wireless communication system in which the length of the LCX cable is shortened has been attracting attention. In this type of wireless communication system, when the length of the LCX cable is several meters to several tens of meters, a portion in which the radio wave leaking from the radio base station becomes stronger than the radio wave radiated from the LCX cable spreads, and is an elongated shape formed by the LCX cable. It may become impossible to create a communicable area.

JP 2005-236745 A

  The problem to be solved by the invention is to provide a radio communication system that can reduce the influence of leakage of radio waves from a radio base station on a leaky transmission path and can contribute to the realization of an elongated communicable area. .

  The wireless communication system of the embodiment includes a wireless base station, a leaky transmission line that is connected directly to the antenna terminal of the wireless base station or via a coaxial cable, and is arranged linearly to form an elongated communication area, A shield body or a radio wave absorber provided so as to surround at least a surface of the radio base station other than the surface facing the arrangement direction of the leaky transmission path.

1 is a schematic configuration diagram showing a wireless communication system according to a first embodiment. The schematic diagram for demonstrating the effect | action of the radio | wireless communications system concerning 1st Embodiment. The schematic block diagram which shows the radio | wireless communications system concerning 2nd Embodiment. The schematic block diagram which shows the radio | wireless communications system concerning 3rd Embodiment.

  Hereinafter, a wireless communication system according to an embodiment will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic configuration diagram showing a wireless communication system according to the first embodiment.

  In the figure, reference numeral 10 denotes a wireless base station such as a wireless LAN access point. The wireless base station 10 has a rectangular parallelepiped housing 11 containing an electronic circuit (not shown), and one side surface 11 a of the housing 11. A coaxial connector (antenna terminal) 12 and a LAN connector 13 provided, and a power cable 14 inserted into the housing 11 from one side surface 11a are provided.

  The housing 11 is made of, for example, a plastic material. A metal film 15 that functions as a shield is attached to the surface excluding the one side surface 11a of the housing 11.

  A LAN cable (not shown) is connected to the LAN connector 13 so that the radio base station 10 can perform wired communication with a server (not shown). An LCX cable 20 is connected to the coaxial connector 12, and the LCX cable 20 is linearly arranged in the left-right direction on the paper surface. And the elongate area | region along the arrangement direction of the LCX cable 20 is a communicable area. The LCX cable 20 is provided with connectors 21 and 22 at both ends, a connector 21 on the radio base station 10 side is connected to the coaxial connector 12, and a termination resistor 23 is connected to the connector 22 on the opposite side.

  With such a configuration, radio waves radiated from the radio base station 10 are sufficiently emitted from one side surface 11a of the housing 11, but are hardly emitted from other surfaces. For this reason, an elongated communication area can be maintained even in a region close to the radio base station 10.

  The reason for this will be described in detail below.

  When the LCX cable 20 is sufficiently long as several tens to several hundreds of meters as in the prior art, even if there is a leakage of radio waves from the radio base station 10 as shown in FIG. The effect is almost eliminated after 10 m. For this reason, the influence of leakage of radio waves from the radio base station 10 on the entire system is small, and the communicable area 30 is an elongated area as shown by the broken line in the figure.

  However, as shown in FIG. 2B, when the length of the LCX cable 20 is several meters to several tens of meters, the portion where the radio wave leaking from the radio base station 10 becomes stronger than the radio wave radiated from the LCX cable 20 spreads. In some cases, it may become impossible to make the elongated communicable area 30 formed by the LCX cable 20. Further, as shown in FIG. 2 (c), if the radio wave radiated from the LCX cable 20 is weakened in an attempt to narrow the communicable area 30, the influence of leakage from the radio base station 10 is further increased. It cannot be narrowed.

  On the other hand, even if the radio base station 10 shields the direction other than the arrangement direction of the LCX cable 20 as shown in this embodiment, the radio wave radiated from the LCX cable 20 is weakened as shown in FIG. Since the influence of leakage from the radio base station 10 is extremely small, the communicable area 30 can be narrowed.

  As described above, according to the present embodiment, by providing the shield so as to surround the direction other than the arrangement direction of the LCX cable 20 of the radio base station 10, the influence of the radio wave leakage from the radio base station 10 on the LCX cable 20 is reduced. It is possible to contribute to the realization of a relatively short and elongated communicable area. Moreover, even if the existing radio base station 10 is used, it can be realized only by sticking the metal film 15 to a surface other than the one side surface 11a of the housing 11, and an effect of great practicality can be obtained.

(Second Embodiment)
FIG. 3 is a schematic configuration diagram showing a wireless communication system according to the second embodiment. In addition, the same code | symbol is attached | subjected to FIG. 1 and an identical part, and the detailed description is abbreviate | omitted.

  The difference between the present embodiment and the first embodiment described above is that the arrangement direction of the LCX cable 20 is set upward rather than on the surface side where the coaxial connector 12 of the radio base station 10 is provided. That is, the LCX cable 20 is linearly arranged in the vertical direction, and the radio base station 10 side of the LCX cable 20 is connected to the coaxial connector 12 provided on the right side surface 11 a of the radio base station 10 via the coaxial cable 40. . The coaxial cable 40 includes coaxial connectors (not shown) at both ends, and these connectors are connected to the connector 21 of the LCX cable 20 and the connector 12 of the radio base station 10, respectively.

  Further, in the present embodiment, the metal film 15 functioning as a shield body is affixed not to the one side surface 11 a of the housing 11 but to all other surfaces except the upper surface 11 b of the housing 11.

  With such a configuration, the emission of radio waves from the radio base station 10 can be restricted only in the upward direction, which is the arrangement direction of the LCX cable 20, and the emission of radio waves in other directions can be suppressed. it can. Therefore, the influence of leakage of radio waves from the radio base station 10 on the LCX cable 20 can be reduced, and the same effect as in the first embodiment can be obtained.

(Third embodiment)
FIG. 4 is a schematic configuration diagram showing a wireless communication system according to the third embodiment. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The difference between the present embodiment and the second embodiment described above is that the radio base station 10 itself is accommodated in a box 50 having a shield function without providing a shield. .

  The box 50 is opened in the upper direction, and the metal film 15 functioning as a shield is attached to the four side surfaces and the lower surface. Instead of attaching the metal film 15, the box 50 itself may be formed of a metal material. Then, the radio base station 10 is arranged in the box 50, and the LCX cable 20 connected via the coaxial cable 40 is drawn upward as in the second embodiment.

  Even in such a configuration, the radio waves radiated from the radio base station 10 are shielded by the box 50 except for the upward direction. Therefore, the same effect as the second embodiment can be obtained.

(Modification)
The present invention is not limited to the above-described embodiments. In the embodiment, a metal film is used as a material having a shielding function. However, the present invention is not limited thereto, and any conductive material may be used. Furthermore, it is also possible to use a conductive material in mesh form instead of film form.

  In addition, it is not necessarily limited to a conductive material, and a radio wave absorber can be used. As the electromagnetic wave absorber, it is desirable to use a dielectric electromagnetic wave absorber in which carbon powder is mixed with a dielectric material such as rubber, foamed urethane, or expanded polystyrene to increase the dielectric loss. It is also possible to use a magnetic wave absorbing material that absorbs radio waves using iron, nickel, ferrite or the like.

  In the embodiment, the shield body or the radio wave absorber is not formed on the surface facing the arrangement direction of the LCX cable, but the shield body or the radio wave absorber may be formed on this surface as well as the other surfaces. . That is, the shield body or the radio wave absorber may be provided so as to surround at least a surface of the radio base station that faces the LCX cable arrangement direction.

  The leaky transmission line is not necessarily limited to the LCX cable, and a leaky waveguide can also be used.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... Wireless base station 11 ... Housing | casing 12 ... Coaxial connector 13 ... LAN connector 14 ... Power cable 15 ... Metal film (shield)
20 ... LCX cable 30 ... Communicable area 40 ... Coaxial cable 50 ... Box

Claims (5)

A radio base station;
A leaky transmission line that is connected to the antenna terminal of the radio base station directly or via a coaxial cable, and is arranged in a straight line to form an elongated communication area;
A shield body or a radio wave absorber provided to surround at least the surface of the radio base station other than the surface facing the arrangement direction of the leaky transmission path;
A wireless communication system comprising:   The wireless communication system according to claim 1, wherein the leaky transmission path is a leaky coaxial cable.   The wireless communication system according to claim 1, wherein the shield body or the radio wave absorber is attached to an outer surface of a casing of the wireless base station.   2. The wireless communication system according to claim 1, wherein the antenna terminal is provided on one side surface of the wireless base station facing the arrangement direction of the leaky transmission path. A radio base station;
Leakage transmission lines connected to the radio base station directly or via a coaxial cable and arranged in a straight line to form an elongated communication area;
An opening in the arrangement direction of the leaky transmission path of the radio base station, a wall surface is formed of a shield body or a radio wave absorber, and a box body containing the radio base station;
A wireless communication system comprising:

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