JP2001045544A - Communication area forming system in wireless communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently use a wireless communication device without the use of an electromagnetic shield even in a space with much communication traffic such as an office building, an exposition and a trade fair. SOLUTION: A plurality of master stations CS for wireless communication devices are placed in a building or a space, each master station is provided with a directive transmitter-receiver 1 while its directivity is directed in a direction of a communication area and a plurality of the directivity transmitter- receiver sets forms communication areas A1-A4. The directivity transmitter- receiver consists of a CS body 2, an omnidirectional antenna 3 provided to the CS body 2 and a reflector 4 placed on the antenna 3, or consists of the CS body 2 and a directivity antenna 5 provided to the CS body 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a PHS (Personal
The present invention relates to a communication area forming method in a wireless communication device such as a handy-phone system.

[0002]

2. Description of the Related Art Here, a PHS for business use will be described as an example. In recent years, information communication processing systems using LANs and other communication lines have been constructed with the OA of office buildings, but securing communication lines has become an issue due to the large-scale system. When the wiring of cables becomes complicated and complicated with the increase of communication information, when rearranging rooms and equipment,
The work of wiring change increases. Therefore, in recent years, with the spread of mobile communication, a building that intends to use a business-use PHS inside the building to improve the efficiency of business is being planned. However, in the case of adopting a radio communication system using radio waves, regulations of the Radio Law on the used frequency band poses a problem. To explain the PHS currently used,
0.30 for public PHS with carrier numbers 1-77
1895.150 to 1917.950 at 0 MHz increments
MHz frequency band, of which 37 radio waves (number of carriers) are allocated to the business-use PHS.
Carriers (call × 35, control × 2), and one carrier is multiplexed by four (call × 3, control × 1).

FIG. 6 shows an example in which a conventional PHS for business use is installed in a factory or the like, and a CS (Cell Station), which is a master station, covers a range where radio waves can reach (electric field strength equal to or higher than a carrier sense level). The cells are distributed and installed to cover the factory. As described above, only three channels can be used by one carrier, and the communicable area of one CS is generally about 100 to 200 m in radius. It cannot be handled by installing CS. Therefore, in such a case, a plurality of CSs are installed in the same communication area according to the amount of communication. When adjacent carriers are used in the same communication area, radio interference may occur.
Switching control is performed so as to use the carrier every other carrier.

[0004]

However, when the PHS for business use is applied to an office building, an exposition, a trade fair, and the like, communication traffic becomes extremely large.
The problem of congestion becomes serious, and the floor area is generally 1000 m
It becomes a realistic punk state in about ² spaces. For example, in an office building, one person per 5 m ²
Assuming that there are S terminals, 200 PHS terminals will be used in 1000 m ² . On the other hand, as described above, in order to avoid radio interference in the same call area, if switching control is performed so as to use every other carrier instead of using an adjacent carrier, the PHS for business use has the following problem. Carrier 2 = 17 carriers 17 carriers x 3 channels = 51 channels only. However, the actual use case is limited to about 40 channels due to radio wave interference and the like. Therefore, the number of CSs that can be effectively installed in the same communication area is 40 channels / 3 channels = 13 units. On the other hand, when the number of PHS terminals is calculated on the basis of the traffic calculation adopted when determining the number of extensions and the call loss rate is 1% and the traffic volume per PHS terminal is 0.15 erlangs, 13 vehicles × 3 channels = 39 Channel (Number of Simultaneously Used Lines) According to the “List of Number of Required Lines for PBX-Accommodated Station Lines” (NTT standard), since the basic traffic on 39 lines is 28.13 erlangs, 28.13 ÷ 0. 15 ≒ 190, and the number of PHS terminals that can be installed in the same communication area is about 200. As described above, in an office building having a floor area exceeding 1000 m ² , if the PHS is entirely introduced, there is a problem that the traffic volume in the same communication area exceeds the processing capacity. That is, 30
Since the size of m × 35 m exceeds 1000 m ² , a large-scale office building usually exceeds this floor area on one floor, and a middle-sized office building also exceeds this floor area on a plurality of upper and lower floors. Therefore, in an office building of a medium size or larger, PHS cannot be used efficiently. In particular, when high-speed data transmission is introduced, since the telephone line is kept connected, the use efficiency of the PHS is further reduced as compared with the above calculation.

[0005] In order to solve this problem, Japanese Patent Application No. Hei 9-1 (1993) has been proposed.
No. 2258 proposes that a floor in a high-density space where communication traffic is large is used to form an electromagnetic partition using electromagnetic shielding materials on surrounding walls, windows, ceilings and floors. With the advent of high-rise buildings, radio waves are reflected on the outer walls of high-rise buildings, and this reflected radio waves cause various types of radio interference, which is a new secondary obstacle.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems. Even in a space having a large traffic volume such as an office building, an expo, or a trade fair, a wireless communication system such as a PHS is used without using an electromagnetic shield. It is an object of the present invention to provide a communication area forming method capable of using devices efficiently.

[0007]

In order to achieve the above object, a communication area forming method in a wireless communication device according to the present invention is provided by installing a master station of a plurality of wireless communication devices in a building or space, and A directional transmitter / receiver is arranged in each station with its directivity directed toward a communication area, and a communication area is formed by a plurality of directional transmitter / receivers.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a communication area forming method when the present invention is applied to a PHS. FIG. 1 (A) is an overall configuration diagram, FIG. 1 (B) and FIG. 1 (C).
FIG. 2 is a configuration diagram of the CS in FIG.

In FIG. 1A, zones Z1 to Z4
Indicates an office building for an office building, an exhibition hall for an expo, and an exhibition space for a trade fair.
CSs that are a plurality of master stations are installed around .about.Z4, respectively. CS in the present invention is a directional transmission / reception device, which forms communication areas (communication cells) A1 to A4 corresponding to the respective zones Z1 to Z4. Although four CSs are installed in each of the zones Z1 to Z4 in the figure, a maximum of thirteen CSs are installed according to the traffic volume of communication as described above.

As shown in FIG. 1B, the directional transmission / reception device 1 has a CS body 2, two rod-shaped omnidirectional antennas 3, and an orthogonal reflecting surface. The antenna gain S (θ) has directivity with a small gain in the lateral direction with respect to the main direction (forward direction). Note that a reflecting device such as a parabolic antenna may be used instead of the reflecting plate 4.

FIG. 1C shows another example of the directional transmission / reception apparatus 1 in which a Yagi antenna 5 is connected to the CS main body 2 to have directivity. Note that a directional antenna such as a loop antenna may be connected instead of the Yagi antenna.

According to the present invention, an apparent radio wave shielding effect can be achieved by giving a directivity to the CS antenna. This will be described with reference to FIG. When the directional transmission / reception device 1 of FIG. 1 is used, the main transmission / reception direction (forward transmission / reception gain) S (f) corresponds to the other direction (for example, the side transmission / reception gain S (s) or the rear transmission / reception gain S).
(b)) has the following apparent shielding effect.

The apparent shielding effect behind the antenna:
S (f) -S (b) Apparent shielding effect on the side of the antenna: S (f) -S
(s) Apparent shielding effect of the antenna in any direction: S (f)-
S (θ) That is, for example, the rear is S
If there is a gain difference of (f) -S (b), compared to the main service area in front of the antenna, it is equivalent to the presence of an electromagnetic shield having a shielding effect of S (f) -S (b). There will be a shielding effect.

FIG. 3 is a sectional view showing another embodiment of the present invention. This embodiment shows an example in which the present invention is applied to a middle-to-high-rise office building 6. If the gray area in the figure is a required communication area, the directional transmission / reception of FIG. 1B or FIG. The device 1 is arranged. Of course, the communication area can be shared between the upper and lower floors. Although the present invention basically realizes a range in which radio waves for the same purpose can be used in a building or space without using a shield such as an electromagnetic shield, the communication area is divided into upper and lower floors. If desired, an electromagnetic shielding material 7 is used as shown in the figure. If there is a deck plate, the electromagnetic shielding material 7 is used if it exists, and if not, an electromagnetic shielding material is separately laid.

FIG. 4 shows another embodiment of the present invention. FIG. 4 (A) is a plan view, and FIG. 4 (B) is a sectional view of the transmission / reception sensitivity adjusting device of FIG. 4 (A). In the present embodiment, as shown in FIG. 4A, when a communication area (communication cell) A1 is formed corresponding to the zone Z1, when it is desired to adjust the transmission / reception sensitivity in a specific part where radio waves are weak. A transmission / reception sensitivity adjustment device 9 which is an antenna attachment device for narrowing the communication range and weakening the intensity of radio waves is provided.

As shown in FIG. 4B, the transmission / reception sensitivity adjusting device 9 has a cylindrical metal cylinder 9a, and the CS main body is disposed inside the metal cylinder 9a so that the antenna 3 is oriented vertically. 2 are provided. A slit 9b is formed in the side surface of the metal cylinder 9a in the horizontal direction, and transmission / reception sensitivity is adjusted according to the opening shape and size of the entire slit 9b to change shielding performance.

FIG. 5 shows a modification of the present invention, in which a plurality of transmission / reception sensitivity adjusting devices 9 of FIG. 4 are arranged in a specific zone Z1. Note that, in this example, the directional transmission / reception device 1 is not used.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made. For example, in the above-described embodiment, a part that reflects a radio wave in a building or space, for example, a wall, a ceiling,
A radio wave absorbing material may be laid on a beam or the like.

[0019]

As is apparent from the above description, according to the present invention, when a wireless communication device such as a PHS is adopted in a space having a large communication traffic volume such as an office building, an expo, or a trade fair, By forming a communication area using the directional transmission / reception device, it is possible to significantly improve the radio wave use efficiency without employing an electromagnetic shield. Further, the present invention can be applied not only to mobile communication but also to LAN.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a communication area forming method in a wireless communication device of the present invention, and FIG.
FIGS. 1B and 1C are configuration diagrams of the CS in FIG. 1A.

FIG. 2 is a diagram for explaining the operation and effect of the present invention.

FIG. 3 is a cross-sectional view showing another embodiment of the present invention.

4A and 4B show another embodiment of the present invention, wherein FIG. 4A is a plan view, and FIG. 4B is a cross-sectional view of the transmission / reception sensitivity adjustment device of FIG. 4A.

FIG. 5 is a plan view showing a modification of the present invention.

FIG. 6 is a diagram for explaining a conventional PHS.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Directional transmission / reception apparatus 2 ... CS main body 3 ... Non-directional antenna 4 ... Reflector 5 ... Directional antenna A1-A4 ... Communication area

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Hayashi 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Corporation (72) Inventor Hirokazu Sato 1-2-3 Shibaura, Minato-ku, Tokyo Shimizu Construction F-term (reference) 5K067 AA13 BB04 EE02 EE10 EE32 EE41 EE53 GG01 GG11 KK02 KK03

Claims (5)

[Claims] 1. A master station for a plurality of wireless communication devices is installed in a building or a space, and a directional transceiver is arranged in each of the master stations with its directivity directed toward a communication area. A communication area forming method in a wireless communication device, wherein a communication area is formed by a transmitting / receiving device. 2. The directional transmitter / receiver comprises: a CS main body;
2. The communication area forming method in a wireless communication device according to claim 1, wherein directivity is given by a non-directional antenna provided on said CS main body and a reflection device arranged on said antenna. 3. The directional transmission / reception device comprises: a CS main body;
3. A communication area forming method in a wireless communication device according to claim 1, further comprising a directional antenna provided in said CS body. 4. A communication area forming method in a wireless communication device according to claim 1, wherein a transmission / reception sensitivity adjustment device is arranged in said communication area by an antenna attachment device. 5. A communication area forming method in a wireless communication device according to claim 1, wherein a plurality of communication areas are shielded by an electromagnetic shield.