JP3376510B2 - Wireless base station - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio base station that communicates with a mobile phone by a radio signal. Particularly, the present invention relates to a wireless base station suitable for use in a system such as a PHS (Personal Handy Horn System) where radio waves are hard to reach such as in a building street or an underground mall, or where a service area locally has a large amount of traffic. It is a thing.

[0002]

2. Description of the Related Art Recently, a PHS (Personal Handy-Hone System) has been put into practical use as a simple system that can be used for mobile phones. This is IS as a repeater
A PHS radio base station is connected to a telephone line network such as a DN line or an analog line and installed on the roof of a building or the like to form a service area, and radio waves are communicated to mobile phones in the area.
It is a system that communicates with ordinary telephones connected to a telephone network.

FIG. 10 is a diagram showing a configuration example of a conventional PHS radio base station. As shown in the figure, the conventional PHS radio base station 1 uses an RCR STD-28 (RCR standard 28) for control and management of an antenna 5, a radio unit 2 that performs radio transmission / reception, and control channels / call channels. An antenna 5 is configured by a control unit 3 that performs wireless control that controls according to the control and operation, diagnosis, and call control management of the entire PHS radio base station, and a line control unit 4 that performs line control on the line network side.
A radio wave signal is transmitted to the entire service area via the mobile phone and communicates with a mobile phone existing in the service area by radio wave.

[0004]

However, since the conventional PHS radio base station forms a service area with one antenna 5, there are places where radio waves cannot reach in buildings, shadows of buildings, underground malls, etc. There was a problem called. As a countermeasure, there is a method of installing a large number of PHS radio base stations to cover, but this method has a problem that the cost is increased and the power consumption is increased.

The present invention has been made in view of the above points, and eliminates the above problems and adds a simple small cell base station to a conventional radio base station to cover a location where radio waves cannot reach. It is intended to provide a wireless base station.

[0006]

In order to solve the above problems, the present invention provides an antenna 11 and a radio section 1 as shown in FIG.
2. A radio base station having a large cell base station 10 that has a line control unit 15 and a control unit 13 and is connected to a telephone line network 16 to convert a communication signal into a radio signal and communicate with a mobile phone. A small cell base station 20 having an antenna 21, a wireless unit 22 and a wireless control unit 23 is installed in a place where radio waves are hard to reach and / or a place with a large amount of traffic in the service area of the cell base station 10. Cell base station 20
And the large cell base station 10 are connected, and the small cell base station 20 supports the service area of the large cell base station 10.

The large cell base station 10 has a large service area a.
While the small cell base station 20 covers the shadow of a building or the like in the service area a, a place where radio waves do not reach in an underground mall, or a waiting place where many people gather, as shown in FIGS. Service areas b in places with heavy traffic such as places
(See FIGS. 2 to 5) to enable communication.

By installing the small cell base station 20, the number of channels on the radio side is increased and the channels on the telephone line side can be effectively used. Therefore, the service area a where calls can be made
By providing the antenna 21 of the small cell base station 20 in a place with a large amount of traffic, the number of times of waiting without an empty channel at the time of transmission is reduced. The small cell base station 20 includes an antenna 21, a radio unit 22, a control unit 23, and an interface unit 24, and other resources use the resources of the large cell base station 10, so that power consumption is reduced. The cost will be low.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a PHS radio base station of the present invention. As shown in the figure, the PHS radio base station of the present invention includes a large cell base station 10 and a small cell base station 2.
It consists of zero. The large cell base station 10 has an antenna 11,
It is composed of a radio unit 12, a main control unit 13, an interface unit 14, and a line control unit 15. The small cell base station 20 is composed of an antenna 21, a radio unit 22, a control unit 23, and an interface unit 24.

The radio unit 12 of the large cell base station 10 sends a radio wave signal to the entire service area through the antenna 11 and receives a signal from a portable telephone. Control unit 13
Includes a radio control unit and a main control unit, and the radio control unit has (1) a CCH (control channel) control function,
(2) Channel management function, (3) TCH (telephone channel) switching function, and other radio control based on RCRSTD-28 (RCR standard 28) are performed, and the main control unit is (1).
It has functions such as channel management, (2) call control management, (3) operational status management, (4) fault detection / maintenance diagnosis management, etc.,
The overall control of the PHS radio base station including the small cell base station 20 is performed.

The interface unit 14 is a small cell base station 20.
Are connected to the control unit 13 (including power supply from a power supply unit (not shown)), and a plurality of small cell base stations 20 can be provided.

The line control unit 15 controls the line on the side of the line network such as an interface function with the ISDN line and the analog line.

The control unit 23 of the small cell base station 20 has the same function as the above radio control unit of the control unit 13 of the large cell base station 10, and the radio unit 22 receives the large cell base station 1 via the antenna 21.
The area covers a large amount of traffic in the area where 0 is not covered (described later) and the service area of the large cell base station 10. The interface unit 24 is the large cell base station 1
It is for connecting with 0.

FIG. 2 shows a case where the PHS radio base station is installed on the roof of a building, and FIG. 2A shows a PH installed on the roof of the building.
FIG. 2B shows a service area formation diagram. As shown in the figure, the antenna 11 of the large cell base station 10 is installed in the center of the roof of the building, and the small cell base station 20 is installed.
The antenna 21 is installed on the edge of the roof of the building. In the service area, as shown in FIG. 2 (B), the antenna 11 covers the area a, and the antenna 21 is a shadow of the building and spot-supports the part b which cannot be covered from the roof of the building (see FIG. 2 (B)).

FIG. 3 shows a case where a PHS radio base station is installed in an underground mall, FIG. 3A shows a PHS radio base station installed in an underground mall, and FIG. 3B shows a service area formation diagram. As illustrated, the antenna 11 of the large cell base station 10
Is suspended from the ceiling on the main street of the underground mall,
The antenna 2 of the small cell base station 20 which forms the screw area a
1 is provided on the ceiling that intersects the main street, forming a service area b (see FIG. 3 (B)).

FIG. 4 shows the case where the PHS radio base station is installed in the arcade, and FIG. 4A shows the PHS installed in the arcade.
The HS wireless base station is shown, and FIG. 4B is a service area formation diagram. As shown in the figure, the antenna 21 of the large cell base station 10 is installed on the roof of a building next to the arcade to form a service area a, and the antenna 21 of the small cell base station 20 is in the arcade. It is installed on the ceiling of No. 1 and the service area b is formed in the arcade (see FIG. 4 (B)).

FIG. 5 shows the case where the PHS radio base station supports the inside and outside of the building. FIG. 5A shows a large cell base station on the roof of the building and a small cell base station in the building, and FIG. ) Shows a service area formation drawing. As shown in the figure, the antenna 11 of the large cell base station 10 is installed on the roof of a building to form a service area a, and the antenna 21 of the small cell base station 20 is installed on the ceiling of a concert hall or a movie theater in the building. Then, the service area b is formed (see FIG. 5B).

As described above, the large cell base station 10 has a wide service area.
In contrast to covering the service area a, the small cell base station 20 forms a service area b in a shadow of a building or the like in the service area a or in a place where radio waves do not reach, such as an underground area, to enable a call. Further, by providing the antenna 21 of the small cell base station 20 in a place where traffic is heavy in the service area a where communication is possible, the number of times the line busy is kept waiting when making a call is reduced.

The above-mentioned radio base station includes an integrated radio base station in which the radio unit 12, the control unit 13, and the line control unit 15 are integrated, and a separate type in which the radio unit 12, the control unit 13, and the line control unit 15 are separated. There is a wireless base station. Which one to use is decided in consideration of cost, maintainability, difficulty of construction, and installation location.

FIG. 6 is a view showing an example of the appearance of an integrated radio base station. As shown, the large cell base station 10 is a base 1
The antenna 11 is supported by the support column 102 at 00, and the main body of the large cell base station 10 of the base 100 is mounted. A switch box 102 for switching transmission / reception and selecting an antenna at the time of transmission is attached to the column 101, and the antenna 11 has a structure in which four rod-shaped antenna members 11a are erected. The main body of the large cell base station 10 and the small cell base station 20 are connected by a cable 31, the switch box 102 and the large cell base station 10 are connected by a cable 32, and a cable 33 is connected between an external device such as a line and a power supply. Connected by.

FIG. 7 is a block diagram showing the system configuration of the integrated radio base station. The antenna 11 is connected to the large cell base station 10 via a switch box 102 by a cable 32. The radio unit 12 of the large cell base station 10 is composed of an RF unit 12-1 and a modem unit 12-2.
2-1 includes an RX (reception) unit 12-1a, a synthesizer unit 12-1b, and a TX (transmission) unit 12-1c, and a modem unit 12-2 includes a DEMOD (Demodulator) unit 12-2a and an RMCE (Remote). Modem Common Equipmen
t) part 12-2b.

The DEMOD section 12-2a is an RX section 12-1.
The analog reception signal from a is digitally converted, and FIR filter processing is performed to convert it to reception demodulation data. RMCE
The section 12-2b processes the received data sent from the DEMOD section 12-2a to form microdiversity, and also uses the received data to perform CRC (Cyclic Redundney Ch
eck) is calculated. Also, the DEMOD section 12-2a
The received data sent from the RMCE composes slots and frames conforming to RCRSTD-28.
Subsequent to the above processing, the unit 12-2b disassembles this slot and frame structure and sends the necessary data to the control unit 13.

On the other hand, the digital signal data sent from the control unit 13 is formed into slots and frames conforming to RCRSTD-28 and converted into transmission modulation data to form an analog modulation signal.

The control unit 13 is composed of a main control unit 13-1 and a radio control unit 13-2, and the radio control unit 13-2 is a CA.
L Link unit 13-2a and CAL Frame unit 13
-2b. The radio section interface defined by RCRSTD-28 defines the type of channel, the usage method of physical slots, etc. as layer 1 (physical layer), and the link access procedure etc. as layer 2 (link layer). -2a is layer 2
Control and the CAL Frame section 13-2b
Controls the interface with the CAL Frame section 13
-2b is for controlling layer 1. Therefore,
For synchronization control such as TDMA frame synchronization, code identification of nodes (mobile station and base station), bit error detection, etc., CAL Fr
This is performed by the ame section 13-2b.

Further, the line control unit 15 uses the I's dedicated to PHS.
Line I / F (interface) unit 15-1, DSU unit 15-2 terminating I'line, and analog line I / F 15
-3 and.

The small cell base station 20 has an interface (I /
F) unit 24, control unit 23, RF unit 22a, and modem unit 2
2b and a radio unit 22, and each unit functions similarly to that of the large cell base station 10.

FIG. 8 is a diagram showing an example of the appearance of a separate type wireless base station. As shown in the figure, the separate type wireless base station houses a large cell base station, as will be described later, a wireless unit housing 10-2 that houses the wireless unit 12, a controller 13, an interface 14, and a line controller 15. The control unit housing 10-1 is configured separately from the base 100.
It is placed in. The wireless unit housing 10-2 and the controller housing 10-1 are connected by a cable 34.

FIG. 9 is a block diagram showing the system configuration of the separate type radio base station. As shown in the figure, the separate type wireless base station includes a control unit 13 and an interface 1.
4 and the line control unit 15 are configured separately from the wireless unit 12, and are respectively housed in the control unit housing 10-1 and the wireless unit housing 10-2 as described above. The function of each unit is the same as that of the integrated wireless base station.

The small cell base station 20 is installed in a place where radio waves are hard to reach, such as a building street or an underground mall, or a place where a large amount of traffic is locally generated in a service area and an area where a lot of calls are made. To reduce the load of 10,
It operates in synchronization with the large cell base station 10. Further, the line addition service and the like use the resources of the large cell base station 10 and employ the remote power supply system in which the power is supplied from the large cell base station 10.

As described above, the small cell base station 20 is installed in an area where a lot of calls are made. However, the number of calls at night is smaller than that in the daytime, and there are areas where the large cell base station 10 alone can sufficiently function. Therefore, in such an area, the power supplied from the large cell base station 10 to the small cell base station 20 can be cut off during a time zone such as nighttime when the call volume is small. in this case,
The rise and fall of the small cell base station 20 is prevented from affecting the service of the large cell base station 10.

As a method for controlling the power supply, automatic control by software or manual control from the center is possible. In this way, the power of the small cell base station 20 is cut off during a time when the communication volume is small, such as at night, and the small cell base station 20 is
By stopping the operation, the PHS service is not hindered, and the power consumption of the base station can be significantly reduced.

[0032]

As described in detail above, according to the present invention, the following excellent effects are expected. (1) Conventionally, a single base station covers a wide service area, whereas the present invention provides a small cell base station so that the shadow of a building or the like in the service area, or
A service area is formed in a place where radio waves do not reach, such as in an underground mall, to enable communication.

(2) Further, by installing a small cell base station, the number of channels on the radio side is increased and the channels on the telephone line side can be effectively used. Therefore, by providing an antenna of a small cell base station in a place where traffic is heavy in a service area where communication is possible, the number of times of waiting without an empty channel at the time of making a call is reduced. The small cell base station comprises an antenna, a radio unit, and a control unit, and the other resources use the resource of the large cell base station, so that the power consumption is reduced and the cost is reduced.

(3) Further, by stopping the operation of the small cell base station during a time when the traffic volume is low, the power consumption of the base station can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a PHS radio base station of the present invention.

FIG. 2 shows a case where a PHS radio base station of the present invention is installed on the roof of a building, and FIG. 2A shows a PHS installed on the roof of the building.
A wireless base station is shown, and FIG. 3B is a diagram showing service area formation.

FIG. 3 shows a case where the PHS radio base station of the present invention is installed in an underground mall, FIG. 3A shows the PHS radio base station installed in an underground mall, and FIG. 3B shows a service area formation. Is.

FIG. 4 shows the case where the PHS radio base station of the present invention is installed in an arcade, and FIG. 4A shows the PH installed in the arcade.
FIG. 3B shows the S radio base station, and FIG. 3B is a view showing the service area formation.

FIG. 5 (A) shows a case where a PHS radio base station of the present invention supports the inside and outside of a building, and FIG. 5 (A) shows a large cell base station on the roof of a building and a small cell base station in the building. FIG. 7B is a diagram showing service area formation.

FIG. 6 is a diagram showing an external appearance example of an integrated PHS radio base station of the present invention.

FIG. 7 is a diagram showing a system configuration of an integrated PHS radio base station of the present invention.

FIG. 8 is a diagram showing an external appearance example of a separate type PHS radio base station of the present invention.

FIG. 9 is a diagram showing a system configuration of a separate type PHS radio base station of the present invention.

FIG. 10 is a diagram showing a configuration example of a conventional PHS radio base station.

[Explanation of symbols]

10 Large cell base station 11 antenna 12 Wireless controller 13 Control unit 14 Interface section 15 Line control unit 20 small cell base stations 21 antenna 22 Radio 23 Control unit 24 Interface part

Front page continuation (72) Inventor Hiroyuki Niijima 2-1-1 Kagahara, Tsuzuki-ku, Yokohama-shi, Kanagawa Kyocera Corporation Yokohama office (56) Reference JP-A-4-28729 (JP, A) JP-A 6-245249 (JP, A) JP-A-7-250371 (JP, A) JP-A-6-233345 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04Q 7/36 H04B 7/26

Claims (2)

(57) [Claims] 1. An antenna, a radio unit, a line control unit, a radio system
In a radio base station having a large cell base station that has a control unit composed of a control unit and a main control unit, is connected to a telephone line network, converts a communication signal into a radio signal, and communicates with a mobile phone, an antenna, Has the same function as the wireless unit and the wireless control unit
Includes a small-cell base station having a that controller, wherein the small-cell base station to connect the large cell base station, the main of the large cell base station
A radio base station, wherein a control unit performs integrated control management including the small cell base station. 2. The radio base station according to claim 1, further comprising means for stopping the operation of the small cell base station during a time period when the traffic volume is low.