JPH10336730A - Communication terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a communication equipment for deciding a base station which operates relay between communication terminals by inputting the output of a position measuring equipment which measures its own position to a zone measuring equipment, and measuring the position of a communication terminal instead of a reception level. SOLUTION: A position measuring equipment 20 inputs each distance between a communication terminal 1 which is outputted by a distance measuring equipment 19 and each of several base station 2, and calculates and outputs a position P of the communication terminal 1. Also, a zone measuring equipment 10 inputs the position P of the communication equipment 1 outputted by the position measuring equipment 20, a moving speed V of the communication terminal 1 outputted by a speed calculator 21, a map outputted by a map data base 22, road information L outputted by a road information extractor 23, and landform information M outputted by a landform information extractor 24, judges the zone of the base station 2 which is proper for the relay of the communication terminal 1 as a zone to which the communication terminal 1 is belonging, and outputs the judged result of the zone. Thus, the position of the terminal can be directly measured, and which base station should operate the relay is decided by using this positioning.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication terminal that performs zone determination of a base station and performs wireless communication using the corresponding base station as a relay station.

FIG. 7 is a diagram showing the relationship between communication terminals, base stations, and zones. In FIG. 1, reference numeral 1 denotes a communication terminal with which a user communicates. 2 is a base station provided with a large number for relaying radio waves transmitted from the communication terminal 1 and radio waves transmitted to the terminal 1;
2b are shown. In addition, 0 is a zone in which each of the base stations 2 is to be in charge of relaying each station, and these are set in advance corresponding to each base station. Here, corresponding to the base stations 2a and 2b,
The respective zones 0a and 0b are shown.

In the example shown in FIG. 7, a communication terminal 1 is connected to a base station 2a.
You are in zone 0a. This means that the communication terminal 1
It means that communicating with the base station 2a is most advantageous. Even if communication is possible with another base station, for example, the base station 2b, the radio waves communicating therewith are weaker than the base station 2a because the distance is long.

[0004] Therefore, the communication terminal 1 determines which base station zone it is in, and performs local communication with the most advantageous base station, thereby relaying the intended communication. Need to be assigned to The present invention relates to a communication terminal device having the above-described zone determination mechanism.

[0005]

2. Description of the Related Art FIG. 8 shows a "mobile phone" supervised by Moruji Kuwahara.
On February 10, 1985, published by The Institute of Electronics, Communication and Communication Engineers,
FIG. 2 is a block diagram showing a configuration of a conventional communication terminal shown as a mobile phone.

In FIG. 8, reference numeral 1 denotes a communication terminal with which a user communicates. Reference numeral 2 denotes a plurality of base stations provided for relaying a radio wave transmitted from the radio wave transmitter 4 of the communication terminal 1 and a radio wave transmitted to the terminal 1. In this example, two base stations 2a and 2b are provided. Stations. In each of the base stations 2, a zone to be in charge of relay of each station is set in advance. 3 is the communication terminal 1
Is a control station that determines which of the above-mentioned zones belongs to, and determines and instructs which of the many base stations 2 to relay the communication.

[0007] In the base station 2, 5 is a radio wave receiver for receiving the radio wave, 6 is a reception level measuring device to which the output of the radio wave receiver 5 is input, and 7 is the reception level measuring device 6.
Is a reception level transmitter that receives the output of the control station 3 and transmits the reception level, and 12 is a determination result receiver that receives the determination result transmitted from the control station 3.

[0008] In the control station 3, reference numeral 8 denotes a reception level receiver that receives the reception level transmitted by the reception level transmitter 7 in the base station 2, and 9 denotes a reception level output by the reception level receiver 8. , And compares the respective reception levels of the respective base stations 2 and outputs the comparison result. The reception level comparator 10 receives the comparison result output by the reception level comparator 9 and Is a zone determination unit that outputs the determination result of the zone to which the zone belongs, and 11 is a determination result transmitter that transmits the determination result output by the zone determination unit 10.

The operation of the above-described conventional communication terminal will be described below. First, in the communication terminal 1, the radio wave transmitter 4 transmits a radio wave. Next, in the base station 2, the radio wave receiver 5 receives the radio wave and outputs a reception signal. The reception level measuring device 6 receives the reception signal, measures the reception level of the signal, and outputs the measured signal. The reception level transmitter 7
The reception level is input, and the reception level is transmitted.

[0010] Since there are a large number of base stations 2, each base station transmits its own reception level to radio waves transmitted by the specific communication terminal 1.

Then, in the control station 3, the reception level receiver 8 receives the respective reception levels transmitted by the respective reception level transmitters 6 in the respective base stations 2 and outputs this. The reception level comparator 9 inputs the respective reception levels corresponding to the respective base stations 2 output from the reception level receiver 8, compares them, and outputs the comparison result. Further, the zone determination unit 10 receives the comparison result of the reception level of each base station output from the reception level comparator 9, and sets the zone of the base station having the highest reception level as the zone to which the communication terminal 1 belongs. Output the judgment result. Then, the determination result transmitter 11 receives the determination result output from the zone determiner 10 and transmits the input to the corresponding base station 2a.

Finally, in the corresponding base station 2a, the decision result receiver 12a receives the decision result transmitted by the decision result transmitter 11 in the control station 3.

By the above operation, it is found that the communication terminal 1 is in the zone of the base station 2a. Thereafter, the base station 2a allocates an empty channel at that time to the communication terminal 1, and Relays communications.

[0014]

As described above, the conventional communication terminal determines the zone based on the reception level when the radio wave transmitted from the communication terminal is received by each base station, and relays the communication terminal. Base station to do was determined. But,
Since the reception level varies greatly over time and greatly varies depending on the propagation path, the determination of the relay base station by this method may be inappropriate or may take a long time. There was a problem that it was not possible to make a decision in consideration of such factors.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and measures a position of a communication terminal instead of a reception level to determine a base station that relays the communication terminal. The purpose is to obtain a terminal.

[0016]

According to a first aspect of the present invention, there is provided a communication terminal which outputs its own position and a zone which selects and outputs one of a plurality of base stations which are in charge of relaying. A determination unit, and the output of the positioning unit is used as the input of the zone determination unit.

A communication terminal according to a second aspect of the present invention includes a map database for storing a map describing each zone to which a base station is in charge of relaying, and uses its output as an input to the zone determiner.

A communication terminal according to a third aspect of the present invention includes a distance measuring device that outputs a distance between the communication terminal and the base station, and uses the output as an input of the position measuring device.

According to a fourth aspect of the present invention, there is provided a communication terminal comprising: a communication terminal side clock for outputting time; a communication terminal side terminal transmission time radio wave transmitter for transmitting a radio wave indicating a transmission time from the communication terminal; A communication terminal side transmission time receiver for receiving a radio wave indicating a transmission time from the communication terminal, and a round-trip propagation time measuring device for outputting a time required for the radio wave to travel back and forth from the communication terminal to the base station. And, the output of the communication terminal side clock, as the input of the communication terminal side terminal transmission time radio wave transmitter and the round trip propagation time measuring device, the response to the transmission of the communication terminal side terminal transmission time radio wave transmitter. The radio wave receiver with transmission time at the communication terminal side receives the output, and uses the output as the input to the round trip propagation time measuring device, and further uses the output as the input to the side ranger.

According to a fifth aspect of the present invention, there is provided a communication terminal comprising: a communication terminal side clock for outputting a time; a base station transmission time-equipped radio receiver for receiving a radio wave indicating a transmission time from the base station; A one-way propagation time measuring device for outputting the time required to reach the communication terminal, wherein the one-way propagation time measuring device measures the output of the communication terminal side clock and the output of the radio receiver with the base station transmission time. , And its output is used as the input of the side ranger.

A communication terminal according to a sixth aspect of the present invention includes a pulse arrival time difference measuring device for outputting a difference in time required for a pulse transmitted from a pair of base stations to arrive at the communication terminal, and outputs the output. This is input to the positioning device.

A communication terminal according to a seventh aspect of the present invention includes a communication terminal clock for outputting a time, and the output is used as an input of the pulse arrival time difference measuring instrument.

A communication terminal according to an eighth aspect of the present invention includes a goniometer for outputting a direction of arrival of a radio wave, and the output is used as an input of the position measuring device.

A communication terminal according to a ninth aspect of the present invention includes a speed calculator for outputting a moving speed of the communication terminal, and uses the output as an input of the zone determiner.

A communication terminal according to a tenth aspect of the present invention includes a road information extractor for outputting information such as a road to which a platform on which the communication terminal is mounted moves, and uses the output as an input to the zone determination unit. is there.

A communication terminal according to an eleventh aspect of the present invention includes a terrain information extractor that outputs information such as terrain that blocks the communication terminal and the base station, and uses the output as an input to the zone determiner.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of a communication terminal according to the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is a block diagram showing a configuration of the first embodiment of the present invention. In the figure, 1 is a communication terminal, and 2 is a base station. As in the prior art, there are many base stations 2, but in this figure, only one is shown. In addition, a zone to be in charge of relaying is set in each base station 2 in advance.

In the communication terminal 1, 13 is a communication terminal side clock for outputting the time, 14 is a communication terminal side terminal transmission time radio wave transmitter for inputting the time and transmitting a radio wave indicating the time, 17 Is a communication terminal-side terminal transmission time-equipped radio receiver that receives a terminal transmission time-equipped radio wave transmitted by the base station-side terminal transmission time-equipped radio transmitter 16 in the base station 2 and outputs a terminal transmission time; The communication terminal clock 1
3 and the terminal transmission time output by the communication terminal side terminal transmission time-attached radio wave receiver 17 are input,
A round-trip propagation time measuring device 19 for dividing the propagation time required for a radio wave for round-trip by two and outputting the result as a propagation time, and a distance measuring device 19 for inputting the propagation time output from the round-trip propagation time measuring device 18 and outputting a distance. The device 20 receives the distance output by the distance measuring device 19 and calculates the distance between the communication terminal 1 and some of the base stations 2 from the distance between the communication terminal 1 and some of the base stations 2.
Is a position calculator that calculates and outputs the position P of the communication terminal 1, a speed calculator that inputs the position P output by the positioner 20, obtains and outputs a moving speed V of the communication terminal 1, and 22 is a base station. Is a map database that outputs a map describing each zone that is in charge of relaying, 23 is a road information extractor that inputs the map output by the map database 22, extracts and outputs road information L, 24 Inputs the map output from the map database 22, and outputs the terrain information M
Is a terrain information extractor that extracts and outputs

In the base station 2, reference numeral 15 denotes a base station-side terminal transmission time at which the communication terminal 1 receives a radio wave transmitted by the communication terminal-side terminal transmission time-equipped radio transmitter 14 and outputs a terminal transmission time. Radio receiver with 16
Is a base station-side terminal transmission time-equipped radio transmitter that inputs the terminal transmission time output by the base station-side terminal transmission time-equipped radio receiver 15 and transmits the terminal transmission time-equipped radio wave indicating the input.

Next, the operation will be described. First, in the communication terminal 1, the communication terminal clock 13 outputs the time.

Radio wave transmitter 14 with transmission time on the communication terminal side
Inputs the time output by the communication terminal side clock 13 and transmits a radio wave with a terminal transmission time, which is described as the terminal transmission time.

Next, in the base station 2, the base station-side terminal transmission time-added radio wave receiver 15 transmits the terminal transmission time-added radio wave transmitted by the communication terminal-side terminal transmission time-added radio wave transmitter 14 in the communication terminal 1. Receiving and outputting the terminal transmission time.

Radio wave transmitter 16 with base station terminal transmission time
Inputs the terminal transmission time output by the base station-side terminal transmission time-added radio wave receiver 15, and transmits the terminal transmission time-added radio wave. This transmission is performed at the same time as the reception of the base station-side terminal transmission time-added radio wave receiver 15 or after a certain time delay.

In the communication terminal 1 again, the communication terminal-side terminal transmission time-added radio wave receiver 17 receives the terminal transmission time-added radio wave transmitted by the base station-side terminal transmission time-added radio wave transmitter 16 in the base station 2. And outputs the terminal transmission time.

The reciprocating propagation time measuring device 18 inputs the time output from the communication terminal clock 13 at the same time as the reception of the radio wave receiver 17 with the communication terminal transmission time. That is, this time is the reception time. Further, the round-trip propagation time measuring device 18 also inputs the terminal transmission time output from the radio terminal 17 with the communication terminal side terminal transmission time. In other words, the round-trip propagation time measuring device 18 determines the transmission time of the radio wave transmitted from the communication terminal 1 and the transmission time of the radio wave
And the reception time when the communication terminal 1 receives the signal again. Therefore, the round-trip propagation time measuring device 18 calculates a time obtained by dividing the propagation time required for the radio wave for this round trip by 2 and outputs the calculated time as a one-way propagation time.

The distance measuring device 19 is a device for measuring the round-trip propagation time 1
8 is input and multiplied by the speed of light to obtain and output the distance between the communication terminal 1 and the base station 2. As described above, since the number of the base stations 2 is large, the distance is determined and output to a specific communication terminal 1 according to the base stations 2.

The positioning device 20 calculates the position P of the communication terminal 1 by inputting the respective distances between the communication terminal 1 and some of the base stations 2 output by the distance measuring device 19. And output.

The speed calculator 21 receives the position of the communication terminal 1 output from the positioning device 20 and calculates and outputs the moving speed V of the communication terminal 1.

On the other hand, the map database 22 outputs a map describing each zone in which the base station is in charge of relaying.

The road information extractor 23 inputs the map output from the map database 22 and extracts and outputs road information L.

At the same time, the terrain information extractor 24 inputs the map output by the map database 22, extracts and outputs terrain information M.

The zone judging device 10 calculates the position P of the communication terminal 1 output from the positioning device 20, the moving speed V of the communication terminal 1 output from the speed calculator 21, and the map database 22. The map to be output, the road information L output by the road information extractor 23, and the terrain information M output by the terrain information extractor 24 are input and are suitable for relaying the communication terminal 1. The zone of the base station 2 is determined as the zone to which the communication terminal 1 belongs, and the determination result of this zone is output.

[0044] The zone judging device 10 communicates with the communication terminal 1.
The operation for determining the zone of the base station suitable for performing the relay of the above will be described in further detail. FIG. 5 is a diagram showing a mechanism of zone determination, and shows a position P of the communication terminal 1, its moving speed V, the map, the road information L, and the terrain information M.

Each zone of each base station 2 shown on the map is not necessarily geometrically simple,
It is defined on the map in consideration of radio wave propagation conditions.
Basically, based on which zone the position of the communication terminal 1 is included in, the zone is determined and the relay base station is determined.

If the position P and the speed V of the communication terminal 1 are applied to the road information L, the base station 2a
Is closer, but if this route is followed, the base station 2b will soon be closer, so it can be determined that the base station 2b should be selected as soon as possible even a little farther.

Further, the position P and speed V of the communication terminal 1
Is applied to the terrain information M, the base station 2a is closer, but since it is in the shade, it can be determined that the base station 2b should be selected a little further away. As described above,
The zone determiner 10 determines a zone of a base station suitable for relaying the communication terminal 1.

The judgment result transmitter 11 inputs the judgment result of the zone output from the zone judging device 10 and transmits it to the corresponding base station 2.

Finally, in the corresponding base station 2, the determination result receiver 12 receives the determination result of the zone transmitted by the determination result transmitter 11 in the communication terminal 1.

By the above operation, the corresponding base station 2
Can determine that the communication terminal 1 is in the zone in which the communication terminal 1 is in charge, and thereafter, allocates an empty channel at that time to the communication terminal 1 and relays the communication.

Embodiment 2 FIG. 2 is a block diagram showing a configuration of the second embodiment of the present invention. In the figure, 1 is a communication terminal, and 2 is a base station. As in the prior art, there are many base stations 2, but in this figure, only one is shown. In addition, a zone to be in charge of relaying is set in each base station 2 in advance.

In the base station 2, reference numeral 25 denotes a base station clock for outputting a time, and reference numeral 26 denotes a time when the time output by the base station clock 25 is input and the base station transmission time is recorded. It is a radio transmitter with a base station transmission time for transmitting radio waves.

In the communication terminal 1, a base station 27 receives the radio wave with base station transmission time transmitted by the radio wave transmitter with base station transmission time 26 in the base station 2 and outputs the base station transmission time. A radio wave receiver with station transmission time 28 receives a time output from the communication terminal side clock 13 and the base station transmission time output from the radio wave receiver 27 with base station transmission time, and transmits a one-way radio wave. Is a one-way transit time measuring device that outputs the transit time required to propagate.

Next, the operation will be described. First, in the base station 2, a base station-side clock 2 provided in the base station is provided.
5 outputs the time.

The base station transmission time-attached radio wave transmitter 26 receives the time output from the base station clock 25 and transmits a base station transmission time-attached radio wave indicating this as the base station transmission time.

Next, in the communication terminal 1, the radio wave receiver with base station transmission time 27 receives the radio wave with base station transmission time transmitted by the radio wave transmitter with base station transmission time 26 in the base station 2. And outputs the base station transmission time.

The one-way propagation time measuring device 28 inputs the time output from the communication terminal clock 13 simultaneously with the reception of the radio wave receiver 27 with the base station transmission time. That is, this time is the reception time. Further, the one-way propagation time measuring device 2
8 also inputs the base station transmission time output by the base station transmission time-attached radio wave receiver 27. That is, the one-way propagation time measuring device 28 obtains the transmission time when the radio wave is transmitted from the base station 2 and the reception time when the propagation is received by the communication terminal 1. Therefore, the one-way propagation time measuring device 28 calculates and outputs the propagation time required for the radio wave to propagate this one-way.

The operation of the communication terminal 1 after the distance measuring device 19, the parallel operation of the map database 22 and thereafter, and the subsequent operation of the decision result receiver 12 in the base station 2 are described above. This is the same as Embodiment 1 of the communication terminal according to the present invention.

Embodiment 3 FIG. 3 is a block diagram showing a configuration of the third embodiment of the present invention. In the figure, 1 is a communication terminal, and 2 is a base station. As in the prior art, there are many base stations 2, but in this figure, only one is shown. Each base station 2 is set in advance with a zone to be in charge of relaying.

In the base station 2, reference numeral 29 denotes a pulse transmitter for transmitting a pulse.

In the communication terminal 1, 30 is a pulse receiver for receiving the pulse transmitted from the pulse transmitter 29 in the base station 2 and outputting the received signal, and 31 is a pulse receiver 30. Is a pulse arrival time difference measuring device that inputs the reception signal output by the communication terminal, inputs the time output by the communication terminal side clock 13 simultaneously with the input, and outputs the pulse arrival time difference.

Next, the operation will be described. First, in the base station 2, a pulse transmitter 2 provided in the base station
9 emits a pulse.

Next, in the communication terminal 1, the pulse receiver 30 is connected to the pulse transmitter 29 in the base station 2.
Receives the above-mentioned pulse and outputs the received signal.

The pulse arrival time difference measuring device 31 receives the received signal output from the pulse receiver 30 and
At the same time as the input, the time output by the communication terminal clock 13 is input. That is, this time is the pulse arrival time. However, in this case, the pulse transmission time cannot be obtained because the pulse transmission time is not known. Therefore,
Pulses are transmitted from the plurality of base stations 2 at the same time, and the relative arrival times of the pulses, that is, the pulse arrival time differences are measured. Then, the pulse arrival time difference measuring device 31 outputs this pulse arrival time difference.

The positioning device 20 receives the pulse arrival time difference output from the pulse arrival time difference measuring device 31. This pulse arrival time difference means a distance difference between the pair of base stations 2 with respect to the specific communication terminal 1. Since the locus having a constant distance difference is a hyperbola having the pair of base stations 2 as focal points, the communication terminal 1 exists at some point on the hyperbola. Therefore, such a base station 2
By changing the method of selecting the pair and obtaining a new hyperbola, the position can be calculated using the combination of the hyperbolas. Thus, the positioning device 20 obtains and outputs the position of the communication terminal 1.

The operation after the speed calculator 21 in the communication terminal 1 and the map database 22
The subsequent operation and the subsequent operation of the determination result receiver 12 in the base station 2 are the same as those of the above-described first embodiment of the communication terminal according to the present invention.

Embodiment 4 FIG. 4 is a block diagram showing a configuration of the fourth embodiment of the present invention. In the figure, 1 is a communication terminal, and 2 is a base station. As in the prior art, there are many base stations 2, but in this figure, only one is shown. In addition, a zone to be in charge of relaying is set in each base station 2 in advance.

In the communication terminal 1, reference numeral 32 denotes a goniometer which receives an output of the radio terminal receiver 17 with the transmission time on the communication terminal side and outputs an angle of the base station 2 with respect to the communication terminal 1.

Next, the operation will be described.

The operation of the base station 2 and the communication terminal 1 other than the goniometer 33 and the position measuring device 20 is the same as that of the above-described first embodiment of the communication terminal according to the present invention.

In the communication terminal 1, the goniometer 33 is
The output of the radio terminal 17 with transmission time on the communication terminal side is input, and the angle of the base station 2 with respect to the communication terminal 1 is output.

On the other hand, in parallel with this operation, the distance measuring device 19
Outputs the distance from the communication terminal 1 to the base station 2.

The positioning device 20 is connected to the distance measuring device 1.
9 and the angle output by the goniometer 33 are input, for example, 1 for one base station.
Two distances and two angles are obtained, and the position P of the communication terminal 1 is calculated and output from these values.

FIG. 6 shows that the positioning device 20 determines the distance between the communication terminal 1 and the base station 2 from one distance and two angles.
FIG. 5 is a diagram showing details of a method for calculating the position of the. As shown in the figure, if the azimuth angle, the elevation angle, and the distance can be measured, the relative positional relationship of the base station 2 with respect to the communication terminal 1 is uniquely determined. Since the position of the base station 2 is known, if this relative positional relationship is determined, the unknown position of the communication terminal 1 will be obtained.

[0075]

According to the first aspect of the present invention, the terminal position is directly measured instead of the reception level where the time fluctuation and the fluctuation due to the propagation path are large, and which base station performs the relay using the measured position is used. Is determined, a communication terminal capable of quick and accurate zone determination can be obtained.

According to the second aspect of the present invention, by providing a map, the zone that each base station is to be in charge of relaying is not limited to a simple geometrical shape, but to a natural situation of the land and an artificial facility situation. It is possible to obtain a communication terminal that can be set with the shape considered.

According to the third aspect of the present invention, since the distance measuring device is provided and its output is used as the input of the position measuring device, it is possible to obtain a small communication terminal capable of performing high-accuracy positioning.

According to the fourth aspect of the present invention, the distance is measured based on the round trip time of the radio wave from the communication terminal to the base station, so that the base station can be constructed at a low cost. It is possible to obtain a communication terminal that does not need to manage clock synchronization and does not need to correct a synchronization error between the clock of the communication terminal and the clock of the base station.

According to the fifth aspect, the distance is measured by the one-way time of the radio wave from the base station to the communication terminal. Therefore, the communication terminal can be configured at low cost and with low power consumption. Communication terminal can be obtained.

According to the sixth aspect, since the propagation time from the base station to the communication terminal does not need to be measured, the base station and the communication terminal can be configured simply and inexpensively as compared with direct distance measurement. And a communication terminal with low power consumption can be obtained.

According to the seventh aspect, since the communication terminal measures the arrival time difference of the pulse, the base station does not need to have a configuration in which the property of the pulse is changed depending on the transmission time, and the accuracy is improved. A communication terminal capable of measuring a high pulse arrival time difference can be obtained.

According to the eighth aspect of the present invention, since the number of base stations to be observed is one, it is possible to reduce the density of base stations and reduce the operation cost of the entire communication system. In addition, a communication terminal capable of quick zone determination can be obtained.

According to the ninth aspect, when the communication terminal moves, it is possible to obtain a communication terminal capable of determining a zone taking into account a position in the near future by using the direction and speed of movement.

According to the tenth aspect, when a communication terminal moves on a road, a communication system capable of determining a zone in consideration of a position in the near future using information on where the road continues. Terminal can be obtained.

According to the eleventh aspect, it is possible to obtain a communication terminal capable of determining a zone in consideration of an influence on radio wave propagation such as a San'in.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a communication terminal according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a communication terminal according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a communication terminal according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a communication terminal according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a mechanism of zone determination in Embodiment 1 of the communication terminal according to the present invention.

FIG. 6 is a diagram illustrating a mechanism of position calculation in a communication terminal according to a fourth embodiment of the present invention.

FIG. 7 is a diagram showing a relationship among communication terminals, base stations, and zones.

FIG. 8 is a block diagram showing a configuration of a conventional communication terminal.

[Explanation of symbols]

0 zone, 1 communication terminal, 2 base stations, 3 control stations,
4 radio wave transmitter, 5 radio wave receiver, 6 reception level measuring instrument, 7 reception level transmitter, 8 reception level receiver, 9
Reception level comparator, 10 zone judgment unit, 11 judgment result transmitter, 12 judgment result receiver, 13 communication terminal side clock, 14 communication terminal side terminal transmission time radio transmitter, 1
5 Radio wave receiver with terminal transmission time on base station side, 16 Radio wave transmitter with terminal transmission time on base station side, 17 Radio wave receiver with terminal transmission time on communication terminal side, 18 Reciprocating propagation time measuring device, 19
Ranging device, 20 positioning device, 21 speed calculator, 22 map database, 23 road information extractor, 24 terrain information extractor, 25 base station clock, 26 radio transmitter with base station transmission time, 27 base station transmission time With radio receiver, 2
8 One-way transit time measuring device, 29 pulse transmitter, 30
Pulse receiver, 31 pulse arrival time difference measuring instrument, 32 goniometer.

Claims (11)

[Claims] 1. A positioning device for outputting its own position, and a zone judging device for selecting and outputting one of the zones in which a number of base stations are in charge of relaying using the output of the positioning device. A communication terminal characterized in that: 2. The apparatus according to claim 1, further comprising a map database storing a map describing each zone to which the base station is in charge of relaying, wherein the zone determining unit receives the map information for the position of the communication terminal from the map database and determines the zone. The communication terminal according to claim 1, wherein the communication terminal is selected. 3. The positioning device according to claim 1, further comprising a distance measuring device for outputting a distance from the base station to the positioning device.
Or the communication terminal according to 2. 4. A communication terminal side clock for outputting a time, a communication terminal side transmission time-equipped radio wave transmitter for receiving an output of the communication terminal side clock and transmitting a radio wave indicating a transmission time from the communication terminal. A communication terminal-side terminal transmission time-attached radio receiver for receiving a response from the base station to the transmission of the radio wave indicating the transmission time, and a radio wave using the output of the communication terminal clock and the output of the receiver. 4. The communication terminal according to claim 3, further comprising: a round trip propagation time measuring device for measuring a time required to make a round trip from the communication terminal to the base station and outputting the time to the distance measuring device. 5. A communication terminal clock for outputting a time, a base station transmission time-equipped radio receiver for receiving a radio wave indicating a transmission time from a base station, an output of the communication terminal clock and a transmission of the base station. And a one-way propagation time measuring device that measures the time required for the radio wave to reach the communication terminal from the base station using the output of the radio wave receiver with time and outputs the measured time to the side rang. The communication terminal according to claim 3. 6. A pulse arrival time difference measuring device for measuring a difference in time required for a pulse transmitted from a pair of base stations to arrive at a communication terminal and outputting the difference to the positioning device. The communication terminal according to claim 1 or 2, wherein 7. The communication terminal according to claim 6, further comprising a communication terminal side clock for outputting a time to said pulse arrival time difference measuring instrument. 8. The communication terminal according to claim 1, further comprising a goniometer that outputs a direction of arrival of a radio wave to said positioning device. 9. A speed calculator for outputting a moving speed of a communication terminal, wherein the zone determiner selects a zone using an output of the positioning device and an output of the speed calculator. The communication terminal according to claim 1. 10. The communication terminal according to claim 2, further comprising a road information extractor for outputting information such as a road to which a platform on which the communication terminal is to be moved to to the zone determiner. 11. The communication terminal according to claim 2, further comprising a terrain information extractor that outputs information such as terrain that blocks the communication terminal and the base station to the zone determiner.