JPH08331082A - Radio communication system of multi-direction multiple connection system - Google Patents

Abstract

PURPOSE: To provide the economical radio communication system having provision for increase/decrease in subscribers remotely from an exchange flexibly. CONSTITUTION: A central control station 2 and plural base stations 4 are connected via a radio channel through at least one relay station 3 and the central control station 2 and the relay station 3 are connected by the TDM(time division multiplex) system, and the relay station 2 and the plural base stations 4 in outgoing transmission are connected by the TDM system and the relay station 2 and the plural base stations 4 in incoming transmission are connected by the TDMA (time division multiplexing access) system respectively. The communication service is served even to subscribers 5 distributed apart from the exchange 1 by installing the relay station 3, and the multiplex address system is adopted for a radio channel 106 interconnecting the relay station 3 and the plural base stations 4 and a radio channel 107 interconnecting each base station 4 and the plural subscriber terminals contained in the station 4 to realize the economical communication system having ease of provision for increase/decrease in subscribers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiple radio access system, and more particularly to a radio communication system for economically providing communication services to subscribers at a plurality of remote points.

[0002]

2. Description of the Related Art Various systems have been proposed for economically providing a switching service to a subscriber located in a remote place from the place where an exchange is installed. Particularly, the system disclosed in Japanese Patent Laid-Open No. 60-32451 provides a concentrator near a remote place where a subscriber exists, and connects the concentrator and the exchange by a multiplexed wireless transmission line. By performing the demand allocation multiple access (DAMA) operation, an economical exchange service can be provided to subscribers scattered over a long distance.

FIG. 5 is a block diagram showing a schematic configuration of the above conventional system. This system has one master station 3
01, and a plurality of slave stations 30 that communicate with this master station 301 by the TDM / TDMA (time division multiplex / time division multiple access) method.
2 and. The master station 301 includes a digital connection conversion circuit (DTI) 401 and a wireless transceiver 402, and the DTI 401 performs signal conversion between the digital highway of the time division switch TDSW and the wireless transmission path.

Each slave station 302 accommodates a plurality of subscriber terminals and has a switching function which is remotely controlled by a time division switch TDSW. The multiplex digital signal transmitted / received by the transceiver 403 is interconverted with the digital signal of the encoder / decoder (CODEC) provided for each subscriber terminal by the multiplex conversion circuit 404, and each subscriber circuit LC.
Is connected to the subscriber terminal through.

[0005]

However, in the above-mentioned conventional system, since each slave station and a large number of subscriber terminals accommodated therein are connected via the laid communication line, the number of subscriber terminals is increased or decreased. Can not respond flexibly to. That is, when a subscriber is added at a certain slave station, it is necessary to add CODEC and subscriber circuits and lay communication lines accordingly, which not only increases equipment costs but also maintains and operates each subscriber communication line. Is also a heavy burden.

Further, when the base station accommodating the subscriber terminal is located far away from the exchange, the parent station 3 is used as in the conventional case.
01 and the slave station 302 cannot be simply connected by a wireless transmission path.

Therefore, an object of the present invention is to provide a wireless communication system capable of providing economical communication service to subscribers far from the exchange.

Another object of the present invention is to provide an economical wireless communication system capable of flexibly coping with the increase and decrease of subscribers far from the exchange.

[0009]

A wireless communication system according to the present invention includes a first control station to which a plurality of subscriber signal lines are connected, and at least one first control station connected to a first control station via a first wireless transmission path. A relay station, a plurality of second control stations connected to one of the relay stations through a second wireless transmission path, and a plurality of subscriber terminals accommodated in each of the plurality of second control stations through a third wireless transmission path , And the transmission signal on the first wireless transmission path follows the TDM method including allocation frames corresponding to a plurality of second control stations, and the downlink transmission signal on the second wireless transmission path uses the same TDM method as the first wireless transmission path. Accordingly, the uplink transmission signal on the second wireless transmission path is
TDM consisting of assigned frames corresponding to control stations
According to the A system, the third wireless transmission line is a TDM including slots corresponding to a plurality of subscriber terminals for each second control station.
It is characterized by following the A method.

[0010]

The downlink transmission signal transmitted from the first control station to the subscriber terminal is TDM having the frame structure of each second control station.
It is transmitted to the second control station through the multiplexed first and second wireless transmission lines, and further transmitted to the subscriber terminal through the TDMA-multiplexed third wireless transmission line having a slot configuration for each subscriber terminal. On the contrary, the uplink transmission signal from the subscriber terminal to the first control station is transmitted from the plurality of subscriber terminals to the second control station by the TDMA method, and is then multiplexed and further transmitted from the plurality of second control stations by the TDMA method. It is transmitted to the relay station. The uplink signal synthesized and multiplexed by the relay station is the first TDM-multiplexed signal.
It is transmitted to the first control station through the wireless transmission path.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a multidirectional multiplex wireless communication system according to the present invention. The system according to this embodiment accommodates a centralized control station 2 directly connected to the exchange 1, a relay station 3 connected to the centralized control station 2 by a wireless line, and a centralized control station 2 via the relay station 3. It is composed of a plurality of base stations 4 (4 _a1 to 4 _ap : p is a natural number) and a plurality of subscriber terminals assigned to each base station. However, in FIG. 1, in order to avoid complexity of the drawing, the base station 4 _a1 and the subscriber terminals 5 _{a-1 to} 5 _a-1 assigned to the base station 4 _a1.
a1-q (q is a natural number), and the base station _4ap and subscriber terminals _{5ap-1 to} 5ap _-q assigned to the base station _4ap are described. Note that the number of subscriber terminals q indicates the number of terminals accommodated in one base station, and is actually an arbitrary number within the maximum number of terminals L for each base station.

The central control station 2 is a TDM radio transmission line 1.
03, the relay station 3 is connected to a plurality of base stations 4 through a time-division multiplex / time-division multiple access (TDM / TDMA) wireless transmission path 106.
Each base station is time division multiple access / time division bidirectional transmission (TDM)
It is connected to a subordinate subscriber terminal through a wireless transmission line 107 of A / TDD system.

The centralized control station 2 comprises a concentrator 21, a TDM demultiplexer 22, a transceiver 23, an antenna 24, and a centralized controller 25. The concentrator 21 focuses the n subscriber lines 100 from the exchange 1 on the m (m <n) digital lines 101. This is because there is almost no probability that n subscriber lines 100 will call at the same time. Demultiplexer 22
Divides the signals of the m digital lines 101 into one TDM transmission line 102, and demultiplexes the multiplexed signals of the digital transmission line 102 into the m digital lines 101.
The total number n of subscriber lines corresponds to the total number of subscriber terminals, and the total number m of digital lines 101 is the same as the total number of TDM lines of the wireless transmission line 103.

The transceiver 23 includes a well-known modulation / demodulation circuit such as QPSK, transmits a time division multiplexed signal to the relay station 3 through the antenna 24, and receives a time division multiplexed signal from the relay station through the antenna 24. . Antenna 24
A non-directional or unidirectional one can be used as. The centralized controller 25 controls the line concentrator 21 and the demultiplexer 22 for TDM.

The relay station 3 includes a central control station 2 and a wireless transmission line 1.
TDM between the antenna 31 and the transmitter / receiver 32 for transmitting and receiving through 03, and the wireless transmission paths 103 and 106.
It includes a demultiplexing device 33 that performs / TDMA control, a transceiver 34 that transmits and receives data to and from the base station 4 through the wireless transmission path 106, and an antenna 35. An omnidirectional or unidirectional antenna can be used as the antenna 35.

Further, the demultiplexer 33 performs TDM control on the downlink signal and TDMA control on the uplink signal. More specifically, the TDM multiplexed signal (downstream signal) received from the wireless transmission path 103 is transferred to the wireless transmission path 106 as the same TDM multiplexed signal, and conversely, the TDMA signal received from a plurality of base stations through the wireless transmission path 106. The (uplink signal) is combined and multiplexed and transferred to the wireless transmission path 103 as a TDM multiplexed signal.

The base stations 4 _a1 to 4 _ap have an antenna 41, a transceiver 42 and a TDM demultiplexer 43 for transmitting and receiving data to and from the relay station 3 through the wireless transmission line 106, a subordinate subscriber terminal and a wireless transmission line 107. It is composed of a TDMA / TDD demultiplexer 44, a transceiver 45, an antenna 46, and a controller 47 for transmitting and receiving through.

The controller 47 controls the TD of the demultiplexer 43.
M control and TDMA / TDD control of the demultiplexer 44 are performed. More specifically, the TDM demultiplexing device 43 demultiplexes only its own slot from the TDM multiplexed signal (downstream signal) received from the relay station 3, and conversely the signal from the TDMA / TDD demultiplexing device 44 is TDM demultiplexed. Turn into. Also, TD
The MA / TDD demultiplexer 44 demultiplexes the TDMA / TDD demultiplexed signal (uplink signal) received from the subscriber terminal and outputs the demultiplexed signal to the TDM demultiplexer 43, and conversely the signal from the TDM demultiplexer 43 to the TDMA. / TDD multiplex.
The antennas 41 and 46 may be omnidirectional or unidirectional.

The subscriber terminal 5 (5 _{a-1 to} 5 _ap-q ) is shown in FIG.
As shown in FIG.
A / TDD assembling / disassembling circuit 53, encoder / decoder (CODEC) 54 for encoding and decoding voice / data,
It includes a microphone 55 and a speaker 56. TDMA / T
The DD assembling / disassembling circuit 53 disassembles the TDMA / TDD frame received from the base station to which it belongs, selects a signal addressed to itself, and assembles a TDMA / TDD frame from transmission voice / data. The antenna 51 may be omnidirectional or unidirectional.

The TDMA / TD of the wireless transmission line 107
As the D frame, the specifications of the second-generation cordless telephone system issued by the Radio Wave System Development Center as a standard may be adopted.

FIG. 3 is a format diagram of a TDM frame in the wireless transmission path 103 of this embodiment. A basic frame of a transmission signal transmitted / received between the centralized control station 2 and the relay station 3 includes a head slot and a plurality of frames assigned to the base stations 4 _{a1 to} 3 _ap . The head slot is further composed of the frame head frame identification bit and the TD of each base station.
And M allocation information. Slots corresponding to a plurality of subscriber terminals accommodated in each base station are allocated to each base station allocation frame. For example, the frame of the base station 4 _a1 is composed of slots A1 _{1 to} A1 _L that can be assigned to a maximum of L terminals, respectively.

FIG. 4 is a format diagram of a TDM / TDMA frame in the wireless transmission line 106 of this embodiment. The basic frame of the downlink transmission signal transmitted from the relay station 3 to the base stations 4 _a1 to 4 _ap is the same as that shown in FIG. Therefore, the downlink transmission signal is the TDM multiplexed signal shown in FIG. 3 from the central control station 2 via the relay station 3 to the base station 4 _a1.
~ 4 _ap respectively. Each base station only needs to select the allocation frame allocated to itself.

On the other hand, the uplink transmission signal transmitted from the base stations 4 _a1 to 4 _ap to the relay station 3 is transmitted by the TDMA frame, that is, the allocation frame pre-allocated for each base station. Slots (A1 _{1 to} A1 _L ...) Corresponding to subscriber terminals accommodated by the base station are pre-allocated to each allocation frame, and the format of each slot is as shown in FIG. subscriber number ID ₁ to the base station number ID _B, a base station accommodated, subscriber number ID ₂ as a communication partner, and a communication data.
The TDMA signals respectively received from the base stations 4 _a1 to 4 _ap are combined and multiplexed by the demultiplexing device 33 of the relay station 3,
It is transferred to the centralized control station 2 as a DM multiplexed signal (one basic frame shown in FIG. 3).

Next, the line allocation control and voice / data communication operation of this embodiment having such a configuration will be described in detail.

(Line Allocation Control) As described above, the n subscriber lines 100 from the exchange 1 are concentrated into m lines by the line concentrator 21, but at this time, line allocation control is required.

First, in the downlink allocation from the exchange 1 to the subscriber terminal 4, when a call occurs on a subscriber line, a base station to be connected (hereinafter referred to as 4 _a1 ) and a subscriber terminal as a destination. (Hereinafter referred to as 5 _a1-1 ) is specified. The centralized control device 25 checks whether or not there is a vacant line in the m digital lines 101, and if there is a vacant line, allocates the calling subscriber line to the concentrating line. Since the number m of digital lines 101 is the same as the number of TDM multiplexing of the wireless transmission path 103, the centralized control device 25 outputs only the TDM slot allocation information to the TDM demultiplexing device 22 to allocate the downlink TDM line. It can be carried out. This TD
The M line allocation information (see the downlink format shown in FIG. 4) is transmitted to the relay station 3 through the wireless transmission line 103, and further transmitted to each base station through the wireless transmission line 106 in the same format.

In each base station that has received the TDM line allocation information, the control device 47 confirms the subscriber number under its control, and the base station 4 _a1 having the corresponding subscriber terminal 5 _a1-1 T
The call origination information is transmitted to the subscriber terminal _5a1-1 through the slot assigned to the DMA / TDD frame. More specifically, the TDM / TDMA demultiplexing device 43 selects an allocation frame allocated to its own station from the basic frames, and the information such as the subscriber ID contained in the selected frame is transmitted to the TDMA / TDMA.
The DD multiplexer / demultiplexer 44 converts it into the TDMA / TDD format and transmits it to the subordinate subscriber terminal 5 _a1-1 through the pre-allocated slot of the wireless transmission path 107.

[0029] Conversely, the subscriber in the uplink allocation from the terminal to the exchange 1, for example, the subscriber terminal 5 when there was a call from _a1-1, base station 4 _a1 to the subscriber terminal 5 _a1-1 belongs
The calling information is transmitted to. That is, T of the wireless transmission path 107
A connection request is transmitted from the subscriber terminal 5 _a1-1 to the base station 4 _a1 through a predetermined slot of the DMA / TDD frame. In the base station 4 _a1 , the calling information is converted from the TDMA / TDD format to the TDM / TDMA format by the TDMA / TDD demultiplexing device 44 and the TDM / TDMA demultiplexing device 43, and the predetermined TDM of the wireless transmission path 106.
It is transmitted to the relay station 3 through the / TDMA slot. In the relay station 3, received signals from a plurality of base stations are combined and multiplexed by the demultiplexing device 33 and transmitted as a TDM multiplexed signal to the centralized control station 2 through the wireless transmission path 103 (FIG. 4).
Upstream format of FIG. 3 and FIG. 3).

In the central control station 2, the central control device 25
Through the TDM / TDMA demultiplexer 22 to the TDM
/ TDMA line side monitoring line usage, concentrator 2
1 monitors the usage status of the subscriber line 100 of the exchange 1. Then, the line is allocated to the concentrator 21 and the TDM / TDMA demultiplexer 22 only when the line allocation conditions of both the TDM / TDMA line and the subscriber line are satisfied, and the connection from the subscriber terminal 5 _a1-1 is made. The request is sent to the exchange 1.

By such a procedure, an up link and / or a down link is allocated between the exchange 1 and the subscriber terminals 5 _{a1-1 to} 5 _ap-q , respectively, and in the case of a telephone, a communication path is established according to a well-known sequence. Established.

(Downlink transmission from switch 1 to subscriber terminal 5) When a downlink is assigned to each subscriber terminal, a voice / data signal is sent from switch 1 through subscriber line 100 to a concentrator of central control station 2. It is input to 21 and concentrated on m digital lines 101. Furthermore, TDM / TDM
The A demultiplexer 22 time-division-multiplexes m voice / data signals together with allocation information on one digital line 102,
The time-division-multiplexed TDM signal is transmitted from the transceiver 23 to the relay station 3 via the wireless transmission path 103, and further from the relay station 3 to each base station via the wireless transmission path 106.

When the time division multiplexed signal is received through the wireless transmission path 106, each base station selects only the assigned frame assigned to itself by the TDM / TDMA demultiplexer 43. The TDMA / TDD demultiplexer 44 allocates a voice / data signal to a predetermined slot of the TDMA / TDD format according to the subscriber ID information of each slot of the selected allocation frame and transmits it to the destination subscriber terminal through the wireless transmission path 107. To do.

(Uplink Transmission from Subscriber Terminal 5 to Exchange 1) When an uplink is assigned from each subscriber terminal to the exchange 1, each base station transmits radio transmission path 107 from each subscriber terminal under its control. Receive voice / data signals through the TDMA / TDD allocation slots of The received signal is TD
The MA / TDD demultiplexer 44 demultiplexes each subscriber terminal, and the TDM / TDMA demultiplexer 43 time-division-multiplexes on one digital line according to the TDM / TDMA format (see the upstream format in FIG. 4). ). The voice / data signal time-division-multiplexed for each base station in this manner is converted into a TDMA signal by the wireless transmission line 10.
6 is transmitted to the relay station 3.

In the relay station 3, the TDMA signals TDM-multiplexed for each base station are further combined and multiplexed by the demultiplexer 33, and centralized control is performed as a TDM multiplexed signal shown in FIG. Sent to station 2.

The time division multiplexed signal received from the relay station is
It is separated into m digital lines 101 by the TDM / TDMA demultiplexing device 22 of the centralized control station 2, and further separated into n subscriber lines 100 corresponding to the subscriber terminals 5 by the concentrator 21 and transmitted to the exchange 1. To be done.

In the above embodiment, the subscriber line 100 connected to the centralized control device 2 is connected to the subscriber terminals 5 _{a1-1 to} 5 _ap-q.
However, the present invention is not limited to this, and may be a line that has already been concentrated and multiplexed, or a line that is connected to another network. The good news is clear.

As the subscriber terminal in the above embodiment, a fixed communication device such as a telephone installed in each home, a mobile terminal such as a mobile phone, or a data communication terminal incorporated in a personal computer. There is.

[0039]

As described in detail above, in the wireless communication system according to the present invention, the centralized control station and the plurality of base stations are wirelessly connected via at least one relay station, and the centralized control station and the relay station are connected to each other. Between the relay stations and a plurality of base stations, the TDM method is used for downlink transmission and the TD method is used for uplink transmission.
They are connected by the MA method.

By installing the relay station, it is possible to provide the communication service to the subscribers scattered from the exchange, and further, the wireless transmission line connecting the relay station and the plurality of base stations and each base. By adopting the multiple access system for both the wireless transmission path connecting the station and the plurality of subscriber terminals accommodated therein, it is possible to realize an economical communication system capable of easily coping with the increase or decrease of the subscribers.

Further, the number M of lines of the wireless transmission line connecting the centralized control station and the relay station is set to be smaller than the number N of subscriber lines, and the usage status of a plurality of subscriber lines and lines included in the wireless transmission line is used. By performing line allocation control between an arbitrary subscriber line and a wireless transmission line based on, the wireless transmission line can be used efficiently.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a multidirectional multiplex wireless communication system according to the present invention.

FIG. 2 is a schematic block diagram showing an internal configuration of a subscriber terminal in the present embodiment.

FIG. 3 is a diagram illustrating a TD used in a wireless transmission path 103 according to this embodiment.
It is a format figure of M frame.

FIG. 4 is a diagram illustrating a TD used in a wireless transmission path 106 according to this embodiment.
It is a detailed format diagram of an M / TDMA frame.

FIG. 5 is a schematic block diagram showing a configuration of a conventional wireless communication system.

[Explanation of symbols]

1 Switch 2 Central Control Station 3 Relay Station 4 (4 _a1 to 4 _ap ) Base Station 5 (5 _{a1-1 to} 5 _ap-1 ) Subscriber Terminal 21 Concentrator 22 TDM Demultiplexer 23 Transceiver 24 Antenna 25 Centralized Control Device 31 Antenna 32 Transceiver 33 TDM / TDMA Demultiplexer 34 Transceiver 35 Antenna 41 Antenna 42 Transceiver 43 TDM / TDMA Demultiplexer 44 TDMA / TDD Demultiplexer 45 Transceiver 46 Antenna 47 Control Device 51 Antenna 52 Transceiver 53 TDMA / TDD Assembly / Disassembly Circuit 54 Encoding / Decoding Circuit 55 Microphone 56 Speaker 100 Subscriber Line 101 Digital Concentration Line 102 Digital TDM Multiplexing Line 103 TDM Radio Transmission Line 104 TDM Multiplexing Line 105 TDM / TDMA Multiplexing Line 106 TDM / TD A wireless transmission path 107 TDMA / TDD radio channel

Claims (5)

[Claims] 1. A first control station to which a plurality of subscriber signal lines are connected, at least one relay station connected to the first control station via a first wireless transmission path, and a second wireless transmission path to the first control station. A plurality of second control stations connected to one of the relay stations, and a plurality of subscriber terminals accommodated in each of the plurality of second control stations through a third wireless transmission path; The transmission signal on the channel is transmitted from the first control station on the second wireless transmission channel to the subscriber terminal according to a time division multiplexing (TDM) method that includes allocation frames respectively corresponding to the plurality of second control stations. The downstream transmission signal according to the same time division multiplexing (TDM) method as that of the first wireless transmission line, the upstream transmission signal transmitted from the subscriber terminal to the first control station in the second wireless transmission line is Multiple second
According to a time division multiple access (TDMA) system including allocation frames corresponding to control stations, the third wireless transmission line includes time division multiple access slots each corresponding to the plurality of subscriber terminals for each second control station. A wireless communication system according to a connection (TDMA) method. 2. The third wireless transmission path is a time division multiple access /
The wireless communication system according to claim 1, wherein the wireless communication system complies with a time division bidirectional transmission (TDMA / TDD) system. 3. A multi-directional multiplex wireless connection type communication system, comprising: a first control station to which a plurality of subscriber signal lines are connected; and a relay station connected to the first control station through a first wireless transmission path. , A plurality of second control stations connected to the relay station via a second wireless transmission line, and a plurality of subscriber terminals accommodated in each of the plurality of second control stations via a third wireless transmission line. The first control station may include the plurality of subscriber signal lines and the first subscriber signal line.
Time division multiplexing (T) including allocation lines corresponding to the plurality of second control stations and lines included in the wireless transmission path.
DM) demultiplexing means for demultiplexing, and the relay station demultiplexes downlink transmission signals transmitted from the first wireless transmission path to the second wireless transmission path according to the TDM method, The second demultiplexing unit demultiplexes a transmission signal according to a time division multiple access (TDMA) method including allocation frames respectively corresponding to the plurality of second control stations, each of the plurality of second control stations A third method of demultiplexing a transmission signal transmitted between the second wireless transmission path and the third wireless transmission path according to the TDMA method including slots corresponding to the plurality of subscriber terminals for each second control station. A wireless communication system comprising: demultiplexing means. 4. A multi-directional multiplex wireless connection type communication system, wherein a switch, a central control station to which N (N is a natural number) subscriber signal lines from the switch are connected, and M (M is a natural number). A relay station connected to the central control station through a first wireless transmission path including a line of M <N), a plurality of base stations connected to the relay station through a second wireless transmission path, and a third wireless transmission A plurality of subscriber terminals accommodated in each of the plurality of base stations through a route, wherein the central control station corresponds the plurality of subscriber signal lines to M lines included in the first wireless transmission line. And a first demultiplexing unit for demultiplexing the transmission signal of the M line according to a time division multiplexing (TDM) method, wherein the relay station comprises the first wireless unit. From the transmission line to the second wireless transmission line A downlink transmission signal transmitted demultiplexed according to the TDM scheme,
It comprises second demultiplexing means for demultiplexing an upstream transmission signal according to a time division multiple access (TDMA) method consisting of allocation frames respectively corresponding to the plurality of second control stations, each of the plurality of base stations 2 selecting means for selecting a downlink transmission signal addressed to the base station from the downlink transmission signals received through a radio transmission path; first multiplexing means for multiplexing the selected downlink transmission signal according to a TDMA method; Separating means for separating the upstream transmission signal received from at least one subscriber terminal through the three wireless transmission paths according to the TDMA method, and the separated upstream transmission signal to the M line included in the second wireless transmission path according to the TDM method. And a second multiplexing means for multiplexing the wireless communication system. 5. The centralized control station further comprises monitoring means for monitoring the usage status of the plurality of subscriber signal lines and the M line included in the first wireless transmission path, and the monitoring means based on the usage status. 5. The wireless communication system according to claim 4, further comprising: a line allocation control unit that allocates a line between a plurality of subscriber signal lines and the first wireless transmission line.