JP2000049518A - Method and device for installing phs base station antenna on radio wave reflective wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide PHS base station antenna installing method and device which use a base station in high efficiency and also with high reliability even at the construction site such as a tunnel. SOLUTION: A PHS base station antenna 4 is installed on a radio wave reflective wall surface 1 surrounding space, separated from the surface 1 to a space side more than about half wavelength of a PHS communication radio wave. A waterproof container 10 made of radio wave penetrating material is preferably locked to the space side of the surface 1, the antenna 4 is mounted within the container 10, separated from the surface 1 more than about half wavelength of the PHS communication radio wave and a dew condensation preventing means 18 is provided in the container 10. Further preferably, a hole 14 with a waterproof function for pulling out a coupling cable 22 is provided in the container 10 and the cable 22 and a communication cable 23 is connected outside the container 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for installing a PHS (Personal Handy phone System) base station antenna on a radio-reflective wall, and more particularly to a radio-reflective wall surrounding a space, for example, a tunnel in a ground tunnel. The present invention relates to a method and an apparatus for efficiently installing a PHS base station antenna on a boundary wall surface between a ground and the ground.

[0002]

2. Description of the Related Art At a construction site such as a tunnel construction site, a PH is used for communication between a staff in a control room and workers in a tunnel and between workers.
S is introduced. FIG. 4 shows an example of a conventional method for performing PHS communication at a tunnel construction site as an example of introducing a PHS to a construction site.

[0003] Referring to FIG.
When performing the HS communication, similarly to the case of performing the PHS communication in the building, the PHS base station is provided for each area where the communication by the PHS telephone (hereinafter, sometimes referred to as a slave unit) 5 in the tunnel 29 is possible. (BaseStation. Hereinafter, it may be simply called a base station or BS.) 3 is installed. The workers 6A to 6F and the work vehicle 7G in the tunnel 29 hold slave units 5A to 5F and 5G, respectively. 4 base stations BS in the same figure
1 to BS4 each have a wirelessly connectable range (hereinafter, referred to as an area range), and can be connected to the child device 5 within the area range. In FIG. 4, the area ranges are arranged in series so as to partially overlap each other.

On the other hand, each of the base stations BS1 to BS4 is connected to a site office by a communication cable 23 provided along the inner wall surface of the tunnel 29.
It is connected to 30 control devices 31. These base station 3 and slave unit 4
The control device 31 forms a PHS communication network in the tunnel construction site. The control device 31 includes
Current location on the 5A-5G network, for example, each slave unit 5A-
The base station 3 to which 5G belongs is stored as location registration information.

[0005] For example, the communication procedure when the worker 6A in the area of the base station BS1 in the tunnel 29 contacts the worker 6F in the area of the base station BS4 is as follows in principle. It is. The telephone number signal of the slave unit 5F held by the worker 6F is transmitted from the slave unit 5A held by the worker 6A. The transmitted telephone number signal is received by the base station BS1, and the control device 3
Transmitted to 1. Control device 31 determines that the position of child device 5F on the network is base station BS4 based on the telephone number of child device 5F and the position registration information. Then base station BS4
Is notified to the base station BS4, and the base station BS4 calls the slave unit 5G held by the worker 6F and performs other incoming call processing, thereby enabling a call between the workers 6A and 6F.

A BS in a conventional construction site hits an anchor on a concrete wall or a metal wall such as a boundary wall between a space in a tunnel and the ground shown in FIG. It is often installed in direct contact. Also, in construction sites where water or water is needed, B
S is a radio wave transmitting fiber reinforced plastic (Fiber-Reinfo
rced Plastics. Hereinafter, it is called FRP. ) It is installed in other plastic waterproof containers.

[0007]

However, the introduction of PHS into a tunnel construction site as shown in FIG. 4 has the following problems.

(1) In the PHS, a direct wave between an antenna of a base station (hereinafter, referred to as a base station antenna) and a slave unit is used, but the base station antenna is mounted on a radio-reflective wall such as a tunnel inner wall. When they are installed in close contact with each other, an obstacle due to a reflected wave is likely to occur. Curve A shown in the graph of FIG. 3 shows a change in received voltage with respect to the distance from the base station antenna when the base station antenna is attached to the inner wall surface of the tunnel in close contact. As can be seen from the curve A in FIG.
When the base station antenna is brought into close contact with the inner wall surface of the tunnel, the fluctuation of the received voltage increases, and stable PHS communication becomes difficult.

[0009] Curve A in FIG. 3 shows that the received voltage abruptly decreases as the distance from the base station antenna increases.
The propagation of radio waves in the tunnel is greatly affected by the diameter of the tunnel, the material of the wall surface, bending, etc.
The area range of the PHS communication may be reduced, and an area where PHS communication is disabled may occur. To avoid this communication loss, B
It is conceivable to narrow the installation interval of S, but in this case, the number of BSs to be introduced increases, so the PHS introduction cost increases,
In addition, installation work requires a lot of labor and cost, which is uneconomical.

(2) At construction sites, malfunctions and failures are likely to occur in the BS, which is a precision instrument, due to environmental conditions. For example, a high-humidity environment where the humidity is 90% or more, such as a tunnel construction site, causes a short circuit in an electric circuit inside the BS and causes a malfunction or a failure. In addition, when dew condensation occurs, a short circuit occurs due to the dew condensation water, which may cause malfunction or failure. Furthermore, dust from excavation and fine particles contained in exhaust gas from a working vehicle may enter the inside of the apparatus, leading to malfunction or failure of the circuit. It is desired to develop a method of installing a BS that can prevent malfunction and failure of the BS and ensure reliability of PHS communication.

An object of the present invention is to provide a base station which can use a base station with high efficiency and high reliability even at a construction site such as a tunnel.
An object of the present invention is to provide a method and apparatus for installing an S base station antenna.

[0012]

SUMMARY OF THE INVENTION The present inventor has found that by installing a base station antenna at a certain distance from the inner wall of a tunnel in relation to the wavelength of a PHS communication radio wave, it is possible to reduce the fluctuation and attenuation of the reception voltage. Was found experimentally. That is, the curve B shown in the graph of FIG. 3 shows the reception voltage with respect to the distance from the base station antenna when the base station antenna is installed at a distance of 5 cm from the inner wall surface of the tunnel using the 1.9 GHz band radio wave as the PHS communication radio wave. Indicates a change. As can be seen from the comparison between the curve A and the curve B in the same drawing, the installation at a distance of 5 cm from the inner wall surface of the tunnel can reduce the attenuation of the reception voltage.

Further, the present inventor has set the base station antenna from the inner wall surface of the tunnel to about half a wavelength or more of the PHS communication radio wave, that is, 1.
In the case of PHS communication radio waves in the 9 GHz band, it has been found that the fluctuation and attenuation of the reception voltage can be made sufficiently small by separating them by about 7.9 cm or more. Curve C in FIG. 3 shows a change in received voltage around the base station antenna when the base station antenna is installed at a distance of 10 cm from the inner wall surface of the tunnel. The curve C shows a range of about 25 m radius centered on the base station antenna and a reception voltage of 70 m.
This indicates that the area can be set to the range of dBμV / m or more. The inventor of the present invention obtains a radio wave propagation characteristic similar to the curve C in FIG. 3 by setting the distance L (see FIG. 1) between the base station antenna and the inner wall surface of the tunnel to be at least about a half wavelength of the PHS communication radio wave. Was confirmed experimentally. The present invention has been completed based on this experimental finding.

Referring to the embodiment of FIG. 1, the method of installing a PHS base station antenna on a radio-reflective wall according to the present invention is as follows. The PHS communication radio waves are installed at a distance of about half a wavelength or more from the PHS communication radio wave on the second side. Here, “the radio wave reflective wall surface 1 surrounding the space 2” is a boundary surface having different electromagnetic properties from the space 2, such as a tunnel inner wall surface in FIG. It refers to a wall surface that reflects part or all of communication radio waves.

Preferably, the waterproof container 10 made of a radio wave permeable material and provided with the dew condensation preventing means 18 is provided on the space 2 side of the radio wave reflective wall surface 1.
And the base station antenna 4 is mounted in the container 10 at a distance of about half a wavelength or more of the PHS communication radio wave from the radio wave reflective wall surface 1.

Referring to FIG. 1, a PHS base station antenna installation apparatus 8 according to the present invention is an apparatus for installing a PHS base station antenna 4 on a radio wave reflecting wall 1 surrounding a space 2. A box 12 made of a radio wave permeable material having a side wall 11 that can be locked to the space 2 side, and a support 16 for supporting the base station antenna 4 at a site in the box separated from the side wall 11 by about half a wavelength or more of the PHS communication radio wave. And a dew condensation preventing means 18 provided in the box 12.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A PHS base station antenna installation apparatus 8 of the present invention shown in FIG.
And the base station antenna 4 is mounted in the waterproof container 10. The waterproof container 10 shown in the figure is a box 12 made of a radio wave permeable material.
And a support 16 for the base station antenna 4, and a side wall of the box 12.
11 can be locked to the space 2 side of the radio wave reflective wall surface 1. The base station antenna 4 is supported by the support 16 at a position separated from the side wall 11 in the box 12 by about half wavelength or more of the PHS communication radio wave. An example of the support 16 is an acrylic support that is locked to the side surface of the side wall 11 inside the box.

However, the support member 16 is connected to the side wall 11 of the box body 12 by PH.
Anything that can support the base station antenna 4 on the inner side of the box separated by about half a wavelength or more of the S communication radio wave is sufficient.
The number and material are not limited to the illustrated example. Also, in FIG.
Side wall 11 is in contact with the radio wave reflective wall surface 1,
The method of locking 11 to radio wave reflective wall surface 1 is not limited to the illustrated example. For example, a bracket or the like may be provided on radio wave reflective wall surface 1 to lock side wall 11 of box 12.

The box 12 is made of, for example, polycarbonate or FR.
The inside of the box is made of the moisture of the space 2 by a radio wave transmitting material such as P,
The base station 3 is formed so that it can be shielded from dust and the like, and prevents malfunction and failure of the base station 3 due to moisture and dust in the space 2. When the lid 12a is provided on the box body 12, a rubber packing of, for example, waterproof IP33D is provided between the lid 12a and the box main body to prevent moisture, dust and the like from entering through the gap.

However, even when the base station 3 is mounted in the box 12, the connection between the inside of the box 12 and the space 2 may be released when a cable is connected or maintenance is performed.
It is difficult to completely prevent moisture and dust from entering the inside.
In particular, moisture that has entered the box 12 may cause malfunction or failure of the base station 3 due to dew condensation due to a temperature change in the space 2. In FIG. 1, dew condensation preventing means 18 is provided in the box 12 to prevent dew condensation in the box 12. FIG. 1 shows an example in which a small flat electric heater is used as the dew condensation preventing means 18, but the dew condensation preventing means 18 is not limited to the illustrated example. For example, a light bulb or a hygroscopic material may be used.

The base station antenna installation device 8 shown in FIG. 1 is locked to the inner wall surface of the tunnel shown in FIG. 4, and the base station 3 is mounted on the installation device 8 so that the tunnel diameter, wall material, bending, etc., can cause radio wave propagation. , A relatively large area range around the base station 3 where the fluctuation of the electric field strength is small can be secured. Conventionally, there has been a restriction that the interval between the base stations 3 must be extremely narrow in consideration of the tunnel diameter, wall material, bending, and the like. However, according to the installation apparatus 8 of the present invention, this restriction is significantly reduced. Since the number of base stations 3 can be alleviated, economical introduction of PHS to a construction site by efficiently disposing a small number of base stations 3 becomes possible. Further, the installation device 8 of the present invention prevents malfunction and failure of the base station 3 and has a high reliability P even under a severe environment of a construction site where a lot of moisture or dust exists.
HS communication can be secured.

Thus, it is possible to achieve the object of the present invention, that is, "a method and an apparatus for installing a PHS base station antenna capable of using a base station with high efficiency and high reliability even at a construction site such as a tunnel".

[0023]

FIG. 2 shows an embodiment of the base station antenna installation device 8 of the present invention in which a spacer 25 is provided between the waterproof container 10 and the radio wave reflective wall surface 1. FIG. The installation device 8 shown in FIG.
And a condensation preventing means 18 and a spacer 25. Spacer 25
Can be locked to the space 2 side of the radio wave reflective wall surface 1, and the side wall 11 of the waterproof container 10 can be mounted to the mounting portion 27 on the spacer 25 opposite to the locking portion 26. . The spacer 25 can be, for example, an acrylic base.
The dew condensation preventing means 18 is the same as in FIG.

The waterproof container 10 shown in FIG.
With 16. The support 16 supports the base station antenna 4 at a position separated from the locking portion 26 of the spacer 25 within the box by about half a wavelength or more of the PHS communication radio wave. In the example of FIG. 2, the support 16 integrated with the dew condensation preventing means 18 is shown. For example, condensation prevention means
Reference numeral 18 denotes a flat electric heater, and the base station 3 can be supported at a position on the electric heater which is separated from the engaging portion 26 of the spacer 25 by about half a wavelength or more of the PHS communication radio wave. The material and function of the box 12 are the same as those in FIG.

According to the embodiment of FIG. 2, the box of the waterproof container 10
Even if a sufficient distance cannot be secured within 12, the distance L between the radio wave reflecting wall surface 1 and the base station antenna 4 can be set to be at least about a half wavelength of the PHS communication radio wave by using the spacer 25 having an appropriate thickness. Can be. In addition, the spacer 25 is
The thickness between the and the mounting portion 27 can be adjustable.

The box 12 shown in FIGS. 1 and 2 has a small hole 14 with a waterproof function for pulling out a connection cable 22. The other end of the connection cable 22 having one end connected to the base station antenna 4 is a small hole.
Pull out from 14 and connect the connection cable 22 outside the waterproof container 10.
Can be connected to the communication cable 23 (see FIG. 4). In this case, cable connection, maintenance, and the like can be performed while the inside of the box 12 is kept out of the external space 2 with respect to moisture and dust. Further, the influence of the space 2 on the base station 3 can be avoided, and the base station 3 can be relocated while being mounted in the waterproof container 10.

The base station antenna installation device 8 in the illustrated example
Has a terminal board box 20 adjacent to the small hole 14 of the box 12. A small hole with a waterproof function is also provided in a portion on the terminal board box 20 corresponding to the small hole 14 of the box 12, and the box 12 is inserted through both small holes.
And the inside of the terminal board box 20 are communicated with each other.
A terminal board 21 is provided in the terminal board box 20, a connection cable 22 drawn from the waterproof container 10 is connected to the terminal board 21, and a communication cable 23 is connected to the terminal board 21 via a waterproof connector 24. By providing the terminal box 20 independently of the waterproof container 12 in which the base station 3 is mounted in this way, it is possible to prevent moisture and dust from entering the base station 3 at a tunnel construction site, for example, while connecting cables and Maintenance can be easily performed. The terminal board box 20 can be made of, for example, plastic or metal, and has a waterproof IP33D or so.

Further, the base station antenna 8 of the illustrated example has a roof 13 to prevent dust in the space 2 from directly accumulating on the waterproof container 1 and hindering the base station 3.

[0029]

As described above, according to the method for installing a PHS base station antenna on a radio wave reflecting wall of the present invention, the PHS communication radio wave is transmitted from the wall to the space side from the wall to the radio wave reflecting wall surrounding the space. , The following remarkable effects can be obtained.

(A) Compared to a case where the base station antenna is directly mounted on the radio wave reflective wall surface, the radio wave propagation characteristics are improved and the fluctuation of the reception voltage is suppressed, so that stable PHS communication can be secured at the construction site. (B) Since the attenuation of radio waves is small and a relatively large area can be secured around the base station, the installation intervals of the base stations can be widened, and PHS can be introduced to the construction site at a lower cost than before. . (C) In addition, since PHS can be introduced into the construction site with a small number of base stations, the work of introducing PHS can be reduced, and PH to the construction site can be reduced.
The introduction of S can be facilitated. (D) By mounting the base station antenna in a waterproof container equipped with condensation prevention means, it is possible to prevent malfunction and failure of the base station due to moisture, condensation, dust, etc. at the construction site, and to provide a highly reliable PH.
S communication can be secured. (E) By making the waterproof container equipped with the base station antenna and the terminal box box equipped with the terminal board independent, cable connection and maintenance can be performed while the base station is disconnected from the undesired environment of the construction site. Connection and maintenance work can be facilitated.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an embodiment of the device of the present invention.

FIG. 2 is an explanatory view of another embodiment of the device of the present invention.

FIG. 3 is a graph showing a difference in radio wave propagation characteristics depending on how a base station antenna is attached.

FIG. 4 is an explanatory diagram of a PHS communication method at a tunnel construction site.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Radio wave reflective wall surface 2 ... Space 3 ... PHS base station (BS) 4 ... PHS base station antenna 5 ... PHS telephone (child unit) 6 ... Worker 7 ... Vehicle 8 ... Antenna installation device 10 ... Waterproof container 11 ... Side wall 12 ... Box 12a ... Lid 13 ... Roof 14 ... Small hole with waterproof function 15 ... Hinge 16 ... Support 18 ... Condensation prevention means 20 ... Terminal board box 21 ... Terminal board 22 ... Connection cable 23 ... Communication cable 24 ... Waterproof connector 25 spacer 26 locking part 27 mounting part 29 tunnel 30 control room 31 control device

Continued on the front page F term (reference) 5J046 AA03 AA12 AA15 AB06 CA08 5J047 AA03 AA12 AA15 AB06 BG05 BG08 5K059 AA00 AA14 5K067 AA41 BB04 BB43 EE10 KK01 LL00

Claims (7)

[Claims] 1. A PHS base station antenna is mounted on a radio-reflective wall surrounding a space and separated from the wall by about half a wavelength of a PHS communication radio wave to the space side.
S base station antenna installation method. 2. The installation method according to claim 1, wherein a waterproof container made of a radio wave permeable material and provided with a dew-condensing means is locked to said space side of said wall surface, and said antenna is inserted into said container from said wall surface through PHS communication. A method for installing a PHS base station antenna on a radio-reflective wall mounted at a distance of at least half a wavelength of radio waves. 3. An apparatus for installing a PHS base station antenna on a radio-reflective wall surrounding a space, comprising: a radio-transmissive material box having a side wall lockable to the space side of the wall; A waterproof container having a support for the antenna provided at a location separated by about half a wavelength or more of a PHS communication radio wave from a side wall, and a PHS base station on a radio wave reflective wall provided with a dew condensation preventing means provided in the box Antenna installation device. 4. An apparatus for installing a PHS base station antenna on a radio-reflective wall surrounding a space, the spacer having a locking portion lockable to the space side of the wall, opposite to the locking portion on the spacer. A box made of a radio wave permeable material having a side wall that can be attached to a side part, and a support for the antenna provided at a part in the box separated from the locking part on the spacer by about half a wavelength or more of the PHS communication radio wave. An apparatus for installing a PHS base station antenna on a radio wave reflective wall surface comprising a waterproof container and a dew condensation preventing means provided in the box. 5. The PHS base station antenna installation apparatus according to claim 3, wherein the box has a small hole with a waterproof function for drawing out a connection cable in the box body. 6. The PHS base station antenna installation apparatus according to claim 5, wherein a cable connection box adjacent to the small hole of said box is provided on a radio wave reflective wall surface. 7. The PHS base station antenna installation apparatus according to claim 3, wherein said dew condensation preventing means is provided on a radio wave reflecting wall serving as an electric heater, a light bulb or a hygroscopic material.