JPH07255084A - Data transmission equipment - Google Patents

Abstract

PURPOSE:To effectively utilize limited radio waves while avoiding conflicts with the frequencies of other base stations. CONSTITUTION:The in-area presence information monitor part 20 of a base station 12 monitors mobile stations registered in its area and stores their information in an in-area presence information storage part 19, and a central control part 17 quits a communication with a mobile station on the basis of the information when the number of communications with mobile stations is small and retrieves radio wave from peripheral base stations by a scanning control part 21, judges whether or not a frequency that is not used by other base stations is usable as the frequency of its station, and makes a communication with the mobile station by using the frequency when the frequency is available. This may be done when the system is actuated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission device used for a digital car telephone or the like.

[0002]

2. Description of the Related Art FIG. 3 shows the configuration of a conventional data transmission device. In FIG. 3, reference numeral 1 is a mobile station. Reference numeral 2 is a base station connected to the mobile station 1 by a radio signal. In the base station 2, 3 is a wireless unit that processes a wireless signal. Four
Is a modulator / demodulator that acquires a received data signal from a received signal from the wireless unit 3 and creates a transmitted signal from the transmitted data signal to the wireless unit 3. Reference numeral 5 is connected to the modulation / demodulation unit 4, and performs error correction coding, scramble coding operation, encryption, and slot assembly on the transmission data signal, and error correction decoding and scramble decoding operation and encryption on the reception data signal. This is a code conversion unit that performs the decoding and the slot decomposition. A data conversion unit 6 is connected to the code conversion unit 5 and performs conversion between a non-voice signal of a wire network or a unique interface and digital data communicated by a wireless signal. A central control unit 7 is connected to the code conversion unit 5 and determines the operation of the base station 2 and communicates a control signal with the mobile station 1. A timing control unit 8 controls the operation timing of the base station 2 and interfaces signals between the central control unit 7 and other units. Reference numeral 9 denotes a location information storage unit for storing information on the mobile station 1 registered in the base station 2.

Next, the operation of the above conventional example will be described.
In FIG. 3, the downlink signal is a control signal from the central control unit 7 or a non-voice signal encoded at the coding rate transmitted from the radio unit 3 by the data conversion unit 6, and an error correction code or scrambled by the code conversion unit 5. Or encrypted and output to the modulation / demodulation unit 4. The modulation / demodulation unit 4 modulates the input data and outputs the modulated data to the wireless unit 3. The wireless unit 3 outputs a radio wave signal from the antenna to the mobile station 1 with a predetermined transmission output power at a predetermined frequency.

On the other hand, the uplink signal is a radio signal from the mobile station 1 only when it needs to be transmitted from the mobile station 1.
Then, the radio section 3 performs amplification and frequency conversion, and the modulation / demodulation section 4 converts it into digital data. The code conversion unit 5 decodes the error correction code, the scramble, and the code on the converted data, decomposes the frame to extract the necessary data, and converts the non-voice signal data to the data. The unit 6 decodes it into non-voice information necessary for the wired network or the unique interface, and transmits the control signal to the central control unit 7. The timing controller 8 controls all these operation timings. The communication between the base station 2 and the mobile station 1 in the above operation is limited to the mobile station registered in the in-zone information storage unit 9.

[0005]

However, in the above-mentioned conventional data transmission apparatus, when a plurality of base stations use the same frequency, radio waves collide with each other and communication cannot be performed. The frequency used for each base station is allocated to the. For this reason, one base station frequently communicates with mobile stations, so the frequency is insufficient, and another base station may be idle without using the assigned frequency. There was a problem that it could not be used effectively.

The present invention solves such a conventional problem, and provides an excellent data transmission apparatus capable of effectively utilizing limited radio waves while avoiding frequency collision with other base stations. The purpose is to do.

[0007]

In order to achieve the above object, the present invention comprises a mobile station capable of transmitting and receiving while moving to and from a base station, the base station being a registered mobile station. Based on the information obtained by monitoring, the communication with the mobile station is interrupted, the radio waves of the surrounding base stations are searched during that period, and the frequency not used by other base stations can be used by the own station. It is provided with a means for capturing as a frequency.

[0008]

Therefore, according to the present invention, it is noted that the uplink signal from the mobile station to the base station does not always exist, and the base station monitors the mobile station registered in the area,
When the number of communications with a mobile station is low, communication with the mobile station is interrupted, radio waves from neighboring base stations are searched during that period, and the frequency not used by other base stations is taken in as the frequency of its own station. This makes it possible to effectively use limited radio waves while avoiding frequency collision with other base stations.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a part of the configuration of a data transmission device according to an embodiment of the present invention. In FIG. 1, 11 is a mobile station. Reference numeral 12 is a base station connected to the mobile station 11 by a radio signal. At the base station 12, 1
Reference numeral 3 is a wireless unit that processes wireless signals. Reference numeral 14 denotes a modulation / demodulation unit that acquires a reception data signal from a reception signal from the wireless unit 13 and creates a transmission signal from the transmission data signal to the wireless unit. Reference numeral 15 is connected to the modulation / demodulation unit 14 to perform error correction coding, scramble coding operation, encryption and slot assembly on the transmission data signal, and error correction decoding, scramble decoding operation and encryption on the reception data signal. This is a code conversion unit that performs decoding and slot decomposition. A data conversion unit 16 is connected to the code conversion unit 15 and performs conversion between a signal of a wired network or an original interface and digital data communicated by a wireless signal. 1
Numeral 7 determines the operation of the base station 12 and controls the mobile station 11, and interrupts the communication with the mobile station based on the obtained information on the location of the mobile station, and transmits the radio waves of neighboring base stations in the meantime. It is a central control unit that searches and controls whether or not a frequency not used by another base station can be used by the local station. A timing control unit 18 controls the operation timing of the base station 12 and interfaces signals between the central control unit 17 and other units. Reference numeral 19 denotes a location information storage unit that stores location information of mobile stations registered in the location, and the central control unit 1
Connected to 7. Reference numeral 20 denotes a location information monitoring unit that monitors location-registered mobile stations and obtains location information such as the number of them and the history of incoming and outgoing calls, and is connected to the location information storage unit 19. Reference numeral 21 denotes a scan control unit that causes the timing control unit 18 to search for radio waves of surrounding base stations and detect frequencies not used by other base stations according to an instruction from the central control unit 17.

Next, the operation of the above embodiment will be described.
In FIG. 1, the downlink signal is a control signal from the central control unit 17 or a non-voice signal encoded by the data conversion unit 16 at the encoding rate transmitted from the wireless unit 13, and an error correction code or scrambled by the code conversion unit 15. Modulation and demodulation unit 14
Is output to. The modulation / demodulation unit 4 modulates the input data and outputs it to the radio unit 13, and the radio unit 13 outputs a radio signal from the antenna to the mobile station 11 at a predetermined transmission output power at a predetermined frequency.

On the other hand, the uplink signal is delivered from the mobile station 11 to the base station 12 as a radio signal only when it needs to be transmitted from the mobile station 11, and the radio section 13 amplifies and frequency-converts the modulated signal. Convert to digital data with. The converted data is subjected to error correction code decoding, scrambling decoding, and cipher decoding to the code conversion unit 15, and the necessary data is extracted by performing frame decomposition, and the non-voice signal is converted to the data conversion unit 16. Is decoded into a non-voice signal required for a wired network or a unique interface, and the control signal is transmitted to the central control unit 17.

In a time division multiple access (TDMA) system represented by a PDC system which is a Japanese standard digital car telephone system, as shown in FIG. 2A, an upstream signal from a mobile station to a base station is transmitted. The existing time is specified periodically for each mobile station. Therefore,
The base station prepares for the reception operation regardless of the presence or absence of the transmission burst from the mobile station at that time, but the uplink signal is not always present. Further, since transmission error is taken into consideration, the system is such that the upstream signal to the base station confirms its response and proceeds to the next procedure, and if it cannot be confirmed, it is retransmitted.

Therefore, in the present embodiment, the in-area information monitoring unit 20 of the base station 12 monitors the mobile stations registered in the area, and the number of mobile stations registered in the area and the history of incoming and outgoing calls thereof. And stores them in the in-zone information storage unit 19. When the central control unit 17 determines from this information that communication with the mobile station may be interrupted, the central control unit 17 of FIG.
As shown in, the communication with the mobile station is interrupted, the scan control unit 21 instructs the timing control unit 18 to receive the radio waves of the peripheral base stations at a timing different from the normal operation state, The central control unit 17 determines whether or not the frequency of the detected other base station can be used as the frequency of the own station by checking or grasping the situation of the peripheral base station based on the decoded data, When it is available, the other base station is notified that the frequency is temporarily borrowed, and the frequency is used to communicate with the mobile station. In addition, the search and acquisition of the radio wave of the peripheral base station,
It can also be done at system startup.

[0014]

As described above, according to the present invention, it is noted that the uplink signal from the mobile station to the base station does not always exist, and the base station monitors the mobile station registered in the area. ,
When the number of communications with a mobile station is low, communication with the mobile station is interrupted, radio waves from neighboring base stations are searched during that period, and the frequency not used by other base stations is taken in as the frequency of its own station. This makes it possible to effectively use limited radio waves while avoiding frequency collision with other base stations.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing a part of a configuration of a data transmission device according to an embodiment of the present invention.

FIG. 2 is a diagram showing an operation timing of the device.

FIG. 3 is a schematic block diagram showing a part of the configuration of a conventional data transmission device.

[Explanation of symbols]

 11 Mobile Station 12 Base Station 13 Radio Section 14 Modulation / Demodulation Section 15 Code Conversion Section 16 Data Conversion Section 17 Central Control Section 18 Timing Control Section 19 In-zone Information Storage Section 20 In-zone Information Monitoring Section 21 Scan Control Section

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location H04B 7/26 109 M (72) Inventor Kazuhiro Umetsu 4 Tsunashima East, Kohoku Ward, Yokohama City, Kanagawa Prefecture No. 3 No. 1 Matsushita Communication Industrial Co., Ltd.

Claims (3)

[Claims] 1. A mobile station capable of transmitting and receiving while moving to and from a base station, wherein the base station communicates with the mobile station based on information obtained by monitoring the mobile station registered in the area. A data transmission device comprising means for interrupting communication, searching for radio waves from surrounding base stations during that period, and taking in a frequency not used by another base station as a usable frequency for the local station. 2. A mobile station capable of transmitting and receiving while moving to and from a base station, wherein the base station is connected to the radio unit for handling high frequency signals, and is connected to the radio unit to convert radio signals and data strings. A modulation / demodulation unit for performing, a code conversion unit connected to the modulation / demodulation unit for encoding / decoding data and assembling / disassembling slots, and connected to the code conversion unit for communicating with a signal of a wired network or a unique interface by a wireless signal. A data conversion unit for converting digital data, communication of a control signal with the mobile station for determining the operation of the base station, and communication with the mobile station based on the obtained area information of the mobile station. A central control unit that suspends and searches for radio waves of surrounding base stations during that period to determine whether or not a frequency not used by another base station can be used by the local station, and control of operation timing of the base station And central system A timing control unit that interfaces signals between the control unit and other units, a location information monitoring unit that monitors a registered mobile station, and a location information that stores location information obtained from the location information monitoring unit. Data transmission including a range information storage unit and a scan control unit that causes the timing control unit to search the radio waves of surrounding base stations to detect frequencies not used by other base stations according to an instruction from the central control unit apparatus. 3. The data transmission device according to claim 1, which is applied to a time division multiplexing system.