JP3332685B2 - Simple mobile phone system using CATV network - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an urban and rural CAT as a transmission medium for a portable telephone system such as a PHS.
The present invention relates to a simple closed-area mobile phone system using a V network.

[0002]

2. Description of the Related Art In recent years, the development of portable telephone systems has been remarkable, and in particular, the explosive introduction boom has occurred due to the low cost and ease of introduction due to the development of a simplified portable telephone system (PHS). Hereinafter, the configuration and operation of the conventional simplified mobile phone system will be described with reference to FIGS.

FIG. 5 is a schematic diagram for explaining the configuration and operation of a conventional simplified portable telephone system, and FIG. 6 is a diagram showing the format of a signal frame constituting a digital signal between a mobile station and the exchange 101. In FIG. 5, 10
8, 109, and 110 are portable mobile phones (hereinafter, referred to as mobile devices) that freely carry and transmit and receive conversations and the like.
101 is a voice signal exchange control and mobile unit 108, 10
9 and 110 (hereinafter, represented by the mobile device 108) are registered exchanges and perform call connection management of communication signals. That is, the location registration of the mobile device 108 must be executed because the mobile device 108 moves, and the exchange 101 needs to always know the current location of the mobile device 108.

A portable cellular phone base station apparatus 208 (or 209) transmits / receives data to / from the mobile station 108 by radio and relays the transmission / reception to the exchange 101 by wire.
1 and 602 are exchanges 101 (private branch exchanges (PBX)).
Etc.) and simplified mobile phone base station apparatuses 208 and 209.
This is a conventional metal wire cable connecting between the two.

[0005] As shown in FIG.
In the format of the digital signal frame transmitted between them, 301 is a communication signal, 302 is a frame synchronization signal for identifying the head of the communication signal, and 303 is position information (the dial number of the mobile device 108, the simplified mobile phone base station 6).
Housekeeping information including the number 01
04 is a destination (or reception) mobile device (for example, mobile device 1
09) control bits corresponding to the D channel indicating the dial number, on-hook, off-hook, and the like; 305, digital information such as 64 Kbps for communication contents such as telephone voice; This is a DC balanced bit for adjusting the number of bits 1 and 0 to the same number.

Next, the operation of the above-mentioned conventional simplified portable telephone system will be described with reference to FIGS. During a normal non-call, the mobile device 108 outputs the voice information 305.
Is invalid, and a communication signal 301 including only the location information (indicated by the housekeeping information 303) is wirelessly transmitted to the nearest simplified portable telephone base station apparatus 208, and the simplified portable telephone base station apparatus 208 Wire cable 60
2, the current position of the mobile device 108 is registered.

Since the transmission range of the simple portable telephone 108 is relatively narrow (radius, approximately 200 to 300 m), the simple portable telephone base station device 208 is installed within the range, and the mobile unit 108 is a simple portable telephone. The telephone base station device 208 changes (for example, to the simplified mobile phone base station device 209).
Immediately, the location information including the location is transmitted to the exchange 101 via the moved portable cellular phone base station apparatus 209, and the registered location information is changed. This communication signal 301
Is transmitted approximately every 100 ms, for example, so that the mobile device 108 can follow even when moving at a considerably high speed.

[0008] When a communication request (a destination dial number (for example, the mobile device 109) is displayed in the control bit 304) is received from the mobile device 108, the mobile device 108 transmits the communication request in the format of the communication signal 301 to the simplified portable telephone. Radio transmission is performed to the telephone base station device 208, from which it is transmitted to the exchange 101 via the metal wire cable 602. Exchange 1
01 detects this and checks the free state of the line for the mobile device 109. That is, the exchange 101 is connected to the mobile unit 109.
Since the location information has already been registered, the metal wire cable 602 is connected to the metal wire cable 601 to which the mobile device 109 is connected, and the line status is checked. To make a ring tone.

When the mobile unit 109 goes off-hook, the ringing tone is extinguished and communication becomes possible.
5 is transmitted to the simplified cellular phone base station apparatus 2
08, the communication signal 301 is further exchanged by the exchange 101 through the metal wire cable 602, transmitted to the simplified cellular phone base station apparatus 209 through the metal wire cable 601, and the mobile station 109 connected thereto. Can talk with.

[0010]

However, in the above-mentioned conventional simple portable telephone system, a so-called single wire system using a metal wire cable is used between each simple portable telephone base station apparatus and the exchange. Therefore, the connection from the exchange to the star-shaped connection has been required. Furthermore, since the transmission range is limited in the simplified mobile phone system, a considerable number of simplified mobile phone base station devices are required. Therefore, there is a problem that the cost of the construction and maintenance is extremely high.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is provided for one simplified portable telephone base station apparatus.
There is no need for individual metal wire cables, facility costs,
It is an object of the present invention to provide a simple mobile phone system with low construction costs and low maintenance costs.

[0012]

In order to achieve the above object, a simplified portable telephone system using a CATV network according to the present invention comprises at least one terminal device connected to the CATV network and a connection between the terminal devices. A mobile device that can move and communicate with another mobile device through the terminal device and the CATV network within its wireless communication range, and a main device connected to one end of the CATV network and controlling communication connection between the mobile devices, The mobile stations communicate with each other using an empty channel of the CATV network.

Further, a simplified portable telephone system using a CATV network according to the present invention achieves the above object,
The CATV network includes a plurality of channels, and the main device and the terminal device select an empty channel from among the plurality of channels for communication, so that the number of terminal devices is larger than the number of channels. Is what you do.

Further, a simplified portable telephone system using a CATV network according to the present invention achieves the above object,
A signal conversion device (means) in which a terminal device outputs a communication signal including position information and voice information from a communication signal from a mobile device and a communication signal including only position information, and a first terminal modulation device (means ) And second terminal modulator (means)
And a communication signal including voice information is modulated via a first terminal modulator (means), and a communication signal including only position information is modulated via a second terminal modulator (means). It is characterized by the following.

Further, a simplified portable telephone system using a CATV network according to the present invention, in order to achieve the above object,
Including a switch for exchanging communications between a plurality of CATV networks under the control of the main unit and for registering position information from the mobile units, the communication range between the mobile units can be extended, and the current position of each mobile unit can be determined. It is characterized in that registration is performed at predetermined intervals to exchange communications between mobile devices.

Further, a simplified portable telephone system using a CATV network according to the present invention achieves the above-mentioned object,
A demodulation device (means) for demodulating communication signals of different transmission speeds by the main device, an interface for adding a portion corresponding to voice information to a communication signal of only position information demodulated by the demodulation device (means), and sending the same to an exchange; A line control device (means) for determining whether to communicate a communication signal including voice information demodulated by the demodulation device (means) to its own CATV network or to another CATV network via an exchange. It is a feature.

Further, a simplified portable telephone system using a CATV network according to the present invention achieves the above object,
The first terminal modulation device (means) has a higher transmission speed than the second terminal modulation device (means), and determines whether or not there is a communication request with respect to the communication signal demodulated by the demodulation device (means) in the main device. If there is a request, it confirms an empty line for the destination mobile station and instructs the originating terminal to communicate a communication signal containing voice information, and the originating terminal follows the first terminal modulator (means) in accordance with the instruction. A communication signal including voice information is transmitted through the communication device.

Further, a simplified portable telephone system using a CATV network according to the present invention achieves the above object,
The terminal device includes a terminal modulation device (means) for switching and modulating to a different transmission rate, and switches and modulates a communication signal containing voice information from the mobile device and a communication signal containing only position information in accordance with an instruction from the main device. It is characterized by the following.

Further, in order to achieve the above object, the communication method of a simplified portable telephone system using a CATV network according to the present invention moves between terminal devices and communicates with other mobile devices within the wireless communication range. At least one terminal device that performs wireless communication with a communicable mobile device is connected to a CATV network,
The method includes the steps of communicating, at different transmission rates, a communication signal including voice information and a communication signal including only position information between mobile devices via an empty channel of a network.

That is, a simplified portable telephone system using a CATV network and a communication method thereof according to the present invention, in order to achieve the above object, use a coaxial line which is already installed and used for the CATV network as a transmission path. And utilizing the vacant channel for transmitting control information and voice information of the simplified portable telephone, thereby enabling each terminal device (simplified portable telephone base station device) to be used. A terminal device can be installed or expanded easily and inexpensively by multiplexing and using a CATV network without installing a metal wire cable, so that a simple mobile phone system can be easily and inexpensively constructed and expanded. It is characterized by being able to do.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A simplified portable telephone system according to an embodiment of the present invention will be described below in detail with reference to the accompanying drawings and FIGS. FIG. 1 is a schematic diagram for explaining the configuration and operation of a simplified cellular phone system according to an embodiment of the present invention, FIG. 2 is a block diagram showing the detailed configuration of the terminal device shown in FIG. 1, and FIG. FIG. 4 is a diagram showing a format of a signal constituting a communication signal for transmitting voice information between a center including a main unit and a mobile unit, and FIG. FIG. 3 is a diagram showing a format of a signal that constitutes a communication signal for transmitting.

First, the configuration of a simplified portable telephone system according to an embodiment of the present invention will be described with reference to FIG. In FIG. 1, reference numeral 100 denotes a center which is connected to one end of a coaxial line constituting a CATV network, and which accommodates at least the exchange 101 and the main unit 111 for a simplified mobile phone system;
Reference numeral 01 designates a call for controlling the exchange of communication signals between the CATV networks which is connected to a number of CATV networks and transmitted through the respective coaxial lines of the CATV networks, registers the position of the mobile unit 108, and controls the exchange of the communication signals. An exchange that performs connection management.

Reference numeral 102 denotes a CA of an urban type or a rural type.
A coaxial line which is a transmission medium for TV, 103 is a coaxial line 102
The main line amplifiers 104 and 105 are for extracting communication signals from the coaxial line 102 to the terminal devices 106 and 107. The branch lines 108, 109 and 110 are portable and freely move to transmit and receive conversations and the like. Simplified portable telephones (hereinafter referred to as mobile units 108), 106 and 107 include a simplified portable telephone base station device of a simplified portable telephone system, and coaxial lines 10 of a CATV network via branching devices 104 and 105.
2 and wirelessly communicates with the mobile station 108 to exchange 101
(Hereinafter, represented by the terminal device 106).

The center 100 includes a head end 112 for transmitting or retransmitting (relaying) video information for constructing a CATV. The center 100 includes a head end 112, a coaxial line 102, a main line amplifier 103, and branching devices 104 and 105. Construct a conventional CATV network. Then, the head end 112
And the main device 111 use different frequency bands.
Do not interfere with each other.

In the center 100, 111 is C
A main unit 113 that is disposed between the coaxial line 102 of the ATV network and the exchange 101 and performs general control of the simplified mobile phone system using the CATV network is an upstream signal (terminal device 10).
6 separates the downstream signal (signal from the main unit 111 to the terminal device 106) from the downstream signal and combines the downstream signal with the upstream signal to transmit the downstream signal to the coaxial line 102; Multiplexes a time-division multiplexed QPSK (4-phase phase shift keying) modulated communication signal received from
Is a demodulator that demodulates to a digital baseband signal for processing in.

Reference numeral 117 denotes a communication request (or a communication request from the mobile unit 108 when the originating mobile unit 108 and the destination mobile unit (for example, the mobile unit 109, hereinafter the same) exist in the same CATV network. A line controller (ie, a different CATV) that searches for a free channel for the destination mobile device 109 and allocates the channel according to a connection request) or a request from another mobile device of the CATV network input via the exchange 101. Exchange between networks is exchange 101
If the line to the destination mobile unit 109 is free and can be connected, the destination mobile unit 10
9, when the destination mobile unit 109 goes off-hook, the ringing tone is turned off and the calling and destination mobile units 108, 109 are connected to the terminal devices 106, 1
07, instructs the microprocessor 203 to transmit a communication signal including voice information, convert the communication signal to be transmitted into the communication signal 401, and switch the terminal modulator to be used to the first terminal modulator 205. I do.

Reference numeral 116 denotes a signal having a format designated by the exchange 101 so that the digital signal demodulated by the demodulator 118 can be received by the exchange 101 (including the conventional communication signal). 3
01 format), 1
A multiplexing device 14 multiplexes a signal from the line controller 117, a signal from the exchange 101, and the like to the coaxial line 102, and 115 modulates a multiplexed digital communication signal (downlink signal) into a QPSK signal. Modulator.

Next, the configuration of the terminal device shown in FIG. 1 will be described in detail with reference to FIG. In the description of FIG. 2, the terminal device 106 that wirelessly communicates with the mobile device 108 will be described as an example. In the terminal device 106, 201 transmits / receives a communication signal 301 in a digital format modulated by a carrier wave to / from the mobile device 108 by radio, demodulates the received communication signal 301, and converts it into, for example, TDMA / TDD. (Time-division multiplexing) A simplified portable telephone functioning in the same manner as the conventional simplified portable telephone base station apparatuses 208 and 209, which outputs to the signal converter 202 as a digital signal such as a signal (hereinafter represented by a TDMA signal). It is a base station device.

Reference numeral 202 denotes a signal converter, which converts an upstream signal (for example, a digital communication signal 301 time-division multiplexed by a TDMA signal) from the simplified portable telephone base station apparatus 201 into a downstream signal. The communication signal 301 from the mobile device 108 is separated from the communication signal 501 including only the position information or the communication signal 401 including the voice information according to the instruction of the microprocessor 203 receiving the instruction from the main device 111 (described later). The communication signal 401 is output to the first terminal modulator 205, and the communication signal 501 is output to the second terminal modulator 206. Also, in the case of the downlink communication signal 401 from the terminal demodulator 204, it converts it into a communication signal 301, combines it with the uplink signal, and outputs it to the simplified cellular phone base station apparatus 201.

Reference numeral 203 denotes a microprocessor for controlling operations of the signal conversion device 202, the terminal demodulator 204, the first terminal modulator 205, the second terminal modulator 206, and the like. In particular, in the case of an uplink signal, the signal conversion device 202 determines the communication signal 301 received from the mobile device 108 to determine whether or not it includes only position information (no communication request). The signal is converted into a communication signal 501 and transmitted to the center 100 through the second terminal modulator 206. Even when a communication request is issued from the mobile device 108 (depending on the presence or absence of a destination dial number), it is converted into a communication signal 501. The signal is transmitted to the center 100 through the second terminal modulator 206 and waits for an instruction from the main device 111.

Further, upon receiving a connection permission instruction from the line controller 117 of the main device 111, the microprocessor 203 immediately transmits the communication signal 301 in the signal converter 202.
Is switched from the communication signal 501 to the communication signal 401, and the terminal modulator to be used is changed to the first terminal modulator 20.
Switch to 5. Therefore, when communication signal 301 including voice information is input from originating mobile device 108, it is converted into communication signal 401 and output to first terminal modulator 205. Reference numeral 204 denotes a downstream signal input from the center 100 via the coaxial line 102 and the combiner 207 (for example, a signal modulated into a time-division multiplexed QPSK, but may be any other form of digital signal. (Represented by a signal) into a digital signal such as a TDMA signal.

Reference numeral 205 denotes T which has all information including the down signal from the signal conversion device 202 and the separated audio information.
Q for transmitting a DMA signal via the coaxial line 102
A first terminal modulator 206 for modulating a PSK signal converts a TDMA signal having only essential information such as position information and control information without including voice information separated from a downstream signal from the signal converter 202 into a coaxial cable 102. The second terminal modulator 207, which has a lower transmission rate than the first terminal modulator, which modulates the signal into a QPSK signal for transmission through the 207, transmits the upstream signal through the same coaxial line 102 as the downstream signal. Or a combiner that separates a downstream signal from an upstream signal and inputs the separated signal.

Next, the configuration of the format of a communication signal including audio information will be described with reference to FIG. In FIG. 3, reference numeral 401 denotes a communication signal for transmitting all information including the voice information 404 between the center 100 and the mobile device 108;
2 is a frame synchronization signal for identifying the head of the communication signal;
Reference numeral 3 denotes housekeeping auxiliary information indicating the number of used main-line amplifiers in the coaxial line, the used equipment, and the state of the transmission path.
Reference numeral 3 denotes housekeeping information including location information (including the dialing number of the calling mobile device 108, the numbers of the calling simple type mobile phone base station devices 601 and 602, the location of the area, the electric field strength of the terminal devices 106 and 107, and the like). , 304 are dial numbers of the destination mobile device 109, off-hook (communication request)
And a control bit corresponding to a D channel indicating on-hook or the like. 404 indicates communication contents such as telephone voice at 32 Kbps.
Audio information composed there as a digital signal such as
An error correction bit 405 detects and corrects an error occurring during transmission.

Further, with reference to FIG. 4, the configuration of the format of a communication signal frame that does not include audio information will be described. Referring to FIG. 4, reference numeral 501 denotes an embodiment of the present invention, and indispensable information such as position information including empty information 408 in which voice information is invalid between the center 100 and the mobile device 108 during a non-call. This is a communication signal with a low transmission rate for transmitting only the location information (in accordance with the housekeeping information 303) during a non-communication, and the dialing of the destination mobile device (for example, the mobile device 109) after off-hook. A control bit 304 including a dial number of the destination mobile device 109 is transmitted together with the keeping information 303.

Reference numeral 408 denotes the position of the audio information frame but does not include the audio information 404. For example, all 1's or all 0's are inserted into the empty information frame to indicate that it is transmission of only position information. It is. In addition, the frame synchronization signal 402, the housekeeping auxiliary information 403, the housekeeping information 303, the control bits 304, the error correction bits 405, and the like are the same as those of the communication signal 401, and thus the description will not be repeated.

Next, the operation of the simplified portable telephone system using the CATV network according to the present embodiment will be described with reference to FIGS. First, in FIG. 1 or FIG. 2, each mobile unit 108 is always at a fixed time interval, for example,
About every 100 ms (other time intervals may be used, for example,
If the time interval is shortened, it is possible to follow even if the moving speed of the mobile device 108 is high). A communication signal 301 is transmitted to the terminal device 106 as a digital radio signal modulated by a carrier wave (hereinafter, also referred to collectively as including only position information). This mobile device 108 is another terminal device,
For example, when the mobile device 108 enters the wireless transmission range of the terminal device 107, the mobile device 108 automatically switches to the terminal device 107 so as to transmit the communication signal 301 including only the position information.

In FIG. 2, in particular, the simplified portable telephone base station apparatus 201 disposed on the mobile device 108 side of the terminal device 106 receives the communication signal 301 from the mobile device 108 and stores the communication signal 301 in the housekeeping information 303 thereof. And information such as the terminal device number, area position, and the electric field strength of the terminal device, and outputs the digital signal to the signal conversion device 202 as a digital signal such as TDMA (time division multiplex). Therefore, the microprocessor 203 monitors the control bit 304 of the upstream communication signal 301 received by the signal conversion device 202, and determines whether it is off-hook and whether there is a dial number.
It is determined whether or not the communication signal 301 includes only the position information or includes a request to transmit voice information.

In this case, since the control bit 304 of the received communication signal 301 indicates on-hook, the position information is determined to be valid, and further determination on the control bit 304 (for example, determination on the destination dial number, etc.)
Is not performed. The signal converter 202 converts a TDMA signal containing only position information into a communication signal 501 under the control of the microprocessor 203 to separate it from a downstream signal, and modulates the communication signal 501 containing only position information.
Output to The second terminal modulator 206 Allocated frequency band for only the uplink signal of the position information by modulating the digital signal of the TDMA such as the QPSK signal (e.g., a plurality of channels allocated below 50 mH _Z)
Is assigned to it and output to the combiner 207.

Since the communication signal 501 having only position information does not include voice information, the frequency band to be used can be narrowed. For example, the frequency band used for the communication signal 401 including voice information is 60K per channel.
While bps is required, the frequency band for the communication signal 501 including only position information not including voice information only uses about 8 Kbps per channel. As described above, by using a channel with a narrow band for the position information, the channel can be used effectively. Also, a communication signal 501 containing only position information is provided.
Since the format of the transmission frame is short, the modulation speed (transmission speed) can be reduced, and the transmission efficiency of the simplified portable telephone system can be greatly improved.

The second terminal modulator 206 modulates the received upstream communication signal 501 into a QPSK signal, and
7, and the combiner 207 combines the QPSK signal with the downstream QPSK signal and transmits the combined signal to the center 100 via the coaxial line 102 via the splitter 104.
The QPSK signal is transmitted through the coaxial line 102 and the main line amplifier 10.
3. Transparently transmitted through the CATV network constructed from the branching devices 104 and 105.

Next, returning to FIG. 1, the QPSK signal received by the combiner 113 of the center 100 is separated from the downlink signal and sent to the demodulator 118 transparently, where it is demodulated into a digital signal such as TDMA. You. The line controller 117 decodes the contents of the demodulated digital signal and determines from the control bits 304 whether or not there is a communication request of the terminal device. In this example, since the transmitted communication signal is the communication signal 501 having only the position information,
It is determined that only position registration is performed. Accordingly, the communication signal 501 is supplied to the interface 116, where the content corresponding to the audio information 305 in the form of the communication signal 301 (for example, 0, 1, 0, 1,.
..) is added, the number of bits is made to match that of the communication signal 301 and converted into the form of the communication signal 301, and the exchange 1
Sent to 01.

The exchange 101 updates the registration with the location information included in the housekeeping information 303 of the communication signal 301 as new location information of the mobile unit 108.
Note that the communication signal 501 including only the position information is not returned to the terminal device 106, but is discarded after registration.

Next, a case where the mobile unit 108 goes off-hook will be described. For communication (conversation by telephone), when the user first goes off-hook, the mobile device 108 inserts a control bit 304 including off-hook information into the communication signal 301 and wirelessly transmits the communication signal 301 to the terminal device 106. In communication between the terminal device 106 and the mobile device 108, an empty channel is automatically selected by the mobile device built-in microcomputer. Microprocessor 20
3 judges the control bit 304 of the communication signal 301 received by the signal converter 202 after the carrier is removed and demodulated through the simplified cellular phone base station apparatus 201, and recognizes that the communication signal 301 is off-hook. Is converted into a communication signal 501 in the signal conversion device 202 in the same manner as in the case where only the position information is used, and the second terminal modulator 2
06 to the center 100.

However, the center 100 only recognizes that the mobile unit 108 has gone off-hook, and only updates the position information in the exchange 101 as in the case of only the location information (on-hook state).

After the mobile unit 108 goes off-hook, the transmission destination dial number (the destination mobile unit is now assumed to be the mobile unit 109 connected to the terminal device 107) is transmitted. In this case, the off-hook is also transmitted. The signal converter 202 of the terminal device 106 converts the received communication signal 301 into a communication signal 501 and converts the
06 and transmitted to the center 100. In this case, the line controller 117 of the center 100 determines from the off-hook and the dial number of the destination mobile device 109 that it is a communication request to the mobile device 109, and determines whether or not there is a free line to the mobile device 109.

If there is no free line, the line controller 117 notifies the terminal device 106 to that effect, and transmits a busy tone to the mobile device 108 that has issued a communication request from the simplified cellular phone base station device 201. Let it. If there is an idle line, the line controller 117 sends the call to and from the destination terminal device 106 and 107.
A call permission signal is returned to. Terminal devices 106, 10
In response to the call permission signal, the microprocessor 203 transmits a ringing tone to the mobile devices 108 and 109 and immediately converts the signal conversion function of the signal conversion device 202 from the communication signal 301 to the communication signal 501. Is converted to a communication signal 401.

Therefore, thereafter, all communication signals 301 from mobile device 108 are converted into communication signals 401 and transmitted to center 100 through first terminal modulator 205. That is, the signal converter 202 receives the instruction of the call permission signal from the line controller 117 of the center 100,
From 08 until the on-hook communication signal 108 is received, it is assumed that all communication signals from the mobile device 108 include voice information, and only position information is not transmitted.

That is, after that, when the mobile unit 109 is off-hook to start a telephone call, the mobile unit 10 does not operate until the on-hook information (end information) is detected in the control bit 304.
8 and 109 are all audio information 4
Since the communication signal 301 is regarded as a communication signal 301 containing the
Is converted to a communication signal 401 there, and is modulated into a QPSK signal through the first terminal modulator 205. As in the case of only the position information, the main signal of the center 100 is transmitted through the combiner 207 and the coaxial line 102. It is transmitted to the device 111.

In main device 111, since the line for mobile device 109 has already been set when the dial number of mobile device 109 is transmitted, communication signal 401 from mobile device 108 transmitted to main device 111 is The signal is separated from the downstream signal by the synthesizer 113, demodulated into a digital baseband signal by the demodulator 118, the dial number of the mobile device 109 is recognized by the line controller 117, and the multiplexer 1
At 14, it is multiplexed with another communication signal from the exchange 101 to become a TDMA signal, modulated at a modulator 115 into a QPSK signal, combined with an upstream signal at a combiner 113, and transmitted via a coaxial line 102 to a destination terminal device. It is transmitted to 107.

The QPSK signal of the communication signal 401 transmitted from the mobile device 108 to the destination terminal device 107 is
07, the signal is separated from the uplink signal.
The signal is demodulated into an MA signal, and the audio information
After being converted to a communication signal 301 containing the received signal 05 and modulated by a carrier in the simplified cellular phone base station apparatus 201, the signal is wirelessly transmitted to the destination mobile station 109, and the voice generated by the mobile station 108 is heard from the receiver. be able to. Then, when either the mobile unit 108 or the mobile unit 109 goes on-hook, a communication signal 301 having a control bit 304 indicating on-hook is transmitted to the center 100, and the line controller 117 determines the termination by the on-hook, and A termination signal is transmitted from the device 117 to each of the terminal devices 106 and 107, and the respective microprocessors 203
In contrast, the communication signal conversion in the signal conversion device 202 is converted into the communication signal 501, and the terminal modulator is changed to the second terminal modulator 206.
Is instructed to switch.

When communication with a mobile station connected to another CATV network is desired, the interface 116 of the main unit 111 transmits the communication signal 401 received from the demodulator 118.
(Digital baseband signal) is converted into a communication signal 301 receivable by the exchange 101 and sent to the exchange 101. The exchange 101 transmits the signal to the destination mobile through a coaxial CATV network to which the destination mobile is connected. Can communicate.

Also, in the present embodiment, the terminal devices 106 and 107 use two modulators for modulating the uplink signal.
You are using one. That is, the communication signal 4 including the voice information
01 and a second terminal modulator 206 that modulates a communication signal 501 that does not include audio information (only includes position information). This is because, according to the present invention, the channel can be more effectively used by separately transmitting the communication signal 501 including only the position information, which may have a narrow band and a low transmission speed.

However, although not shown in the figure, as another embodiment of the present invention, only one terminal modulator for modulating an uplink TDMA signal to a QPSK signal is provided, and the first terminal modulator and the The two terminal modulators may have two functions. As a specific embodiment, a terminal modulator including a plurality of digital filters is provided at the first and second terminal modulators.
In response to an instruction of a control signal such as a transmission rate switching signal from the control unit 11, the digital filter is switched to switch the modulation rate of the communication signal 401 of audio information and the communication signal 501 of only position information, thereby changing the transmission rate. can do.

As described above, according to the present embodiment, C
Terminal device 1 for simplified mobile phone system using ATV network
Reference numeral 06 can construct a simplified portable telephone system using an urban or rural CATV as a transmission path without changing the communication procedure of the exchange 101, the simplified portable telephone system 201, and the mobile unit 108 of the simplified portable telephone system.

Further, a signal transmitted on a transmission medium such as a coaxial line usually includes information which cannot be lost such as position information.
01 and the communication signal 401 including the voice information 305 when the mobile device 108 talks, the line utilization efficiency can be improved.

Although this system has been described for a self-employed system in which communication procedures are not unified, it can be applied to public and other portable telephone systems in which interface conditions are defined at the S point of ISDN. it can.

[0057]

The simplified portable telephone system and method using the CATV network according to the present invention are constructed as described above, and in particular, the urban or rural CAT is used as the transmission line.
By multiplexing using the V network and transmitting the communication signal of the position information using another channel with a narrow band, facility costs, construction costs, maintenance and management costs, and the like can be maintained at low cost. Therefore, it is possible to easily and inexpensively construct and expand a simple portable telephone system, and it is possible to greatly improve the line use efficiency.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining the configuration and operation of a simplified mobile phone system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a detailed configuration of the terminal device shown in FIG.

FIG. 3 is a diagram showing a format of a signal constituting a communication signal for transmitting voice information between a center including a switchboard and a main unit and a mobile station;

FIG. 4 is a diagram showing a format of a signal constituting a communication signal for transmitting only positional information between a mobile station and a center including an exchange and a main unit.

FIG. 5 is a schematic diagram for explaining the configuration and operation of a conventional simplified mobile phone system.

FIG. 6 is a diagram showing a format of a signal frame constituting a digital signal between the mobile station and the exchange 101;

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 center 101 switch 102 coaxial line 103 main line amplifier 104, 105 branch unit 106, 107 terminal unit 108, 109, 110 mobile unit 111 main unit 112 head end 113, 207 combiner 114 multiplexer 115 modulator 116 interface 117 line control Device 118 demodulator 201, 208, 209 simplified type mobile phone base station device 202 signal converter 203 microprocessor 204 terminal demodulator 205 first terminal modulator 206 second terminal modulator 301, 401, 501 communication signal 302, 402 Frame synchronization signal 303 Housekeeping information 304 Control bits 305 Audio information 306 DC balanced bits 403 Housekeeping auxiliary information 404 Audio information 405 Error correction bits 408 Empty information 601 and 602 Tal wire cable

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI H04Q 7/30

Claims (2)

(57) [Claims] At least one terminal device connected to a CATV network, and another terminal device that moves between the terminal devices and passes through the terminal device and the CATV network within a wireless communication range and uses an empty channel of the CATV network. A mobile device that can communicate with other mobile devices, a main device that is connected to one end of the CATV network, and controls communication connection between the mobile devices, and the terminal device receives location information and voice from a communication signal from the mobile device. Signal conversion means for outputting a communication signal including information and a communication signal including only position information; first terminal modulation means having different transmission speeds;
Wherein the communication signal including the voice information is modulated via the first terminal modulation means, and the communication signal including only the position information is modulated via the second terminal modulation means. A simplified mobile phone system characterized by the following. 2. The CATV network includes a plurality of channels, and the main unit and the terminal device select an empty channel from among the plurality of channels to perform communication. 2. The simplified portable telephone system according to claim 1, wherein the number is increased.