JPS5820177B2 - Polling communication method from mobile station to fixed station - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides polling from a mobile station to a fixed station.
This invention relates to a communication system using the l ing) format.

Conventionally, when using a wireless communication circuit with poor transmission quality, a mobile station would allocate an address to a fixed station, transmit question data sequentially, and attempt to obtain response data due to changes in transmission quality that change from moment to moment. High-quality data exchange was not possible due to data errors during the propagation path.

In addition, if there is no response, the same inquiry data is sent multiple times, resulting in a low effective transmission speed, and even if you try to operate with multiple waves to obtain the optimal transmission frequency, the equipment cost will be high and it will be difficult to implement. was there.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and by implementing the present invention, aircraft and ships that move over wide areas at relatively high speeds using wireless communication lines with poor transmission quality such as short wave (HF) lines can be used. etc., when attempting to obtain responses to data polled from multiple fixed stations, it is possible to obtain data of relatively good quality even when using a wireless line whose conditions change from moment to moment. Since there is no need to repeatedly transmit the same data in order to obtain a good response, an effective data exchange network can be realized using the HF line, with no reduction in the effective transmission speed.

The present invention will be explained in detail below using examples.

Figure 1 is an example of a communication system, where a, b, and c are mobile stations,
X2. X3. Yl, Y2. Y3 is a fixed station.

In addition, Fig. 2 is an example circuit diagram of a transmitting/receiving device of a mobile station;
Figure 4 shows an example of the circuit configuration of a fixed station transmitting and receiving device, Figure 4 shows an example of the circuit configuration of a fixed station central control unit, Figure 5 shows an error correction flowchart, and Figure 6 shows the data format for transmission and reception. .

In Figure 1, how many fixed station groups are there in which the fixed stations that answer questions from mobile stations a, b, c, etc. are distributed over as wide an area as possible, and fixed stations at multiple locations are grouped into one group? Furthermore, in the example shown in this figure, Xl, X2, X3 are fixed stations belonging to the same group G, Yl, Y2, . Y3
are fixed stations of another group G2, and are fixed stations of a similar group G3. G4゜... shall be provided.

Before commencing communications, it is necessary to determine in advance a selective calling code for the mobile station to use to call these groups of fixed stations.

For example, mobile station a is Xl, X2. When attempting to obtain a response to a question for group G of X3, the transmitting device shown in FIG. 2 is used as shown in FIG.

- Send the question data in the do format.

The question message is stored in advance in the memory 2 via the interface section 1 of FIG. 2 using a terminal device, such as a keyboard of a printing telegraph machine or a league.

First, the address code transmitter 3 receives a control signal from the controller 5.
is Xl, X2. When the G of X3 and the 2 brigadier general code corresponding to the address code for calling the group are transmitted, this is converted into a modulation signal for modulating the transmitter 7 in the modulation section 6, and the transmitter 7
, is transmitted via antenna AT.

Note that the transmitter 70 is turned on and off by a control signal from the control section 5.

Now, the well-known M-sequence code consisting of 2n-1 bits is adopted as the address code for calling the group. For example, A1 in FIG.
Set to 00.

After sending out the address code, the query data is read out character by character from memory 2 and sent to the error correction code adding section (E, jl).
) Sent to 4.

In E, jl 4, a parity code is added so that code errors within the wireless transmission path can be detected and corrected on the receiving side.

That is, a parity code p is added to the information (2), but a well-known BCH code, for example, is used as an error correction code.

The interrogation data in the form of a digital code to which an error correction code has been added is transmitted via the modulator 6, the transmitter 7, and the antenna AT in the same way as the address code.

For example, Figure 6-1.

-cm Dl is the question data.

Once all the question data has been sent, the address code transmitter 3
A data sending end code, ie, a stop code, is sent from the receiving side to notify the receiving side of the end of the interrogation data.

This stop code is composed of an M-sequence code like the address code, and when n=3 is used, it is c in FIG. 6.

~do becomes 0101110. Next, the fixed stations, that is, the groups having the same address code on the receiving side at this time, simultaneously receive the above inquiry data, and the received data of each station is sent to the central control unit of the group via a dedicated line using, for example, a microwave line or a wired line. All data are collected in the central fixed station controller (central fixed station control unit), and optimal data is output using the apparatus shown in FIG. 4 and the process shown in the error correction flowchart shown in FIG.

Then, the optimum data and each fixed station X1°X2. Comparing the data received by X3 at the same time, the station with the least error data is determined to be the transmitting fixed station that provides the optimum line quality, and the response data is transmitted from that fixed station.

For example, in the communication system shown in Figure 1, if X2° is determined to be the optimal transmitting fixed station, the transmitting device of the X2 station is activated and
-Reply in the data format shown in h.

Now send the inquiry message in Figure 6 1 to each fixed station X1 of G1 group.
．． X2. X3 is the receiving device in Figure 3, and 3 in Figure 6 respectively.
, 4, 5, C1 to d1. Assume that simultaneous reception is performed such as C2-d2° and C3-d3.

Therefore, referring to FIG. 3, the upper part of the figure is a fixed station receiving device, and the received output that has passed through the receiving antenna A'R1 receiving section 14 is converted into a digital signal by the demodulator 15 and temporarily stored in the memory section 18.

The signal from the memory section 18 is sent to the dedicated line L3 via the output section 19 in response to a signal from the control section 17.

For example, the data sent by the X1 station to the dedicated line is shown in Figure 6.3.
In the signals a, to d1, a1 to b1 are address data, and b
1 to C3 are question data, and C1 to d1 are stop codes.

Reference numeral 16 denotes a control signal detection section which operates the control section 17 only when the address code of the own station's group, which is predetermined from the output of the demodulator 15 and stored in the memory 18, is detected.

Here, for convenience, the explanation of FIG. 4 will be given.

FIG. 4 shows the configuration of the central control unit, which is divided into sections and is configured so that received signals from a plurality of fixed stations located in a wide area are collected at one location via a dedicated line and error correction is performed.

That is, the received signals from each fixed station are 25 and 26.

270 input to each interface section and memory 2
8.29.30 etc.

After time base adjustment is performed here, the synchronization detection section 31 performs synchronization correction on the bits and words of the three stations.

This synchronization correction is performed using the address code A previously assigned to the G1 group and the arriving address data AAI 1) AH2 and AI 3 at addresses 3.4 and 50 in FIG.

That is, more than a certain number of bits out of all the bits that arrive are A.
1. If it matches, the break point between data and address is set.4.
b2. It is determined that the position is b3, and the characters to be compared in the three stations have been synchronized.

After synchronization correction, an error correction unit (EPR2) 32 performs error correction and comparison using the information (2) for three stations and the harrity code p.

The correction flow diagram is shown in FIG.

In step A in FIG. 5, the fixed station X1 of the G1 group receives information 1 and the parity code p.

It is detected whether there is an error or not, and if it is determined that there is no error, 1 is outputted to the output stage 32.

If it is determined that there is an error, the presence or absence of an error is detected in step B using the information I2 and parity p2 received by the fixed station X2, and if it is determined that there is no error, 2 is output to the output stage 33.

If it is determined that there is an error, the received signal of the fixed station X3 is verified and outputted in step C, similar to A and B.

In step D, errors are corrected for all three stations, and optimum data is output based on a majority decision based on matching between the same bits.

An example is Xl. X2. The data output after error correction of each X3 station is 101100.001100.100.
If it is 100, the output of bit matching majority vote is 101100
becomes.

Returning to FIG. 4, the output of the error correction section 32 is outputted from the output section 33 to a terminal such as a printer or puncher of a printing telegraph machine.

The error counter section 34 in FIG. 4 uses the final output in FIG.
) are compared character by character and the number of error data of each station is added up to detect the receiving fixed station with the least number of errors.

This becomes the station at the transmission point selected for response, and the transmission control section 35 controls the transmission of the fixed station that responds to the interrogation data from the mobile station through the -1 line.

Returning to FIG. 3 again, the input derived from the -1 line of the selected fixed station is input to the control section 17 to operate the transmitter shown in FIG.

For example, if 4 D1□ out of 3.4 and 5 in FIG. 6 has the smallest number of data errors, fixed station X2 is selected.

Since the response data is stored in the memory section 23 from the terminal device as described above through the interface section 24, the data in this memory section is transferred character by character to the next stage's error correction code addition section (Ept2) by the control signal of the control section 17. )
Send it out on the 22nd.

In this Ept 222, a parity code p for error correction is added character by character to the information ■, and the information is converted into a modulated signal in the modulating section 21 at the next stage.

The transmitter 20 transmits a transmission wave modulated with this modulation signal via an antenna A'T via a wireless line.

6-2 in FIG. 6 are the response messages, of which e
-f is the start signal ST, f to g are the response data D2
, g%h is the stop signal SP.

Note that a parity code p is added to the information (2) in the response data as well as in the question data.

Next, the mobile station receives response data using the receiving device shown in FIG. 2, and its operation will be explained.

After the mobile station has finished transmitting the interrogation data, it operates the receiver 8 using a control signal from the control unit 5 (the signal input received by the receiver is converted into a digital signal by the demodulation unit 9, and the signal input is converted to a digital signal by the control signal detection unit). 10, if a start signal as shown in e-f of FIG. The data is stored in the memory section 12 at the next stage, and outputted to a terminal device (not shown) via the time base adjustment output section 13.

When the control signal detection section 10 detects the stop signal gh shown in FIG. 6, the control section 5 outputs a control signal to stop the receiving operation.

In this way, the interrogation and response operations from the mobile station to the G1 group of fixed stations are completed.

The mobile station then moves Y, , Y2 . The G2 group consisting of Y3 is asked and answered in the same manner as the G1 group, and the other groups are polled in turn.

Furthermore, as shown in 6 of Fig. 6, if there is no response even after t1 seconds after transmitting the query data to a certain fixed station group Gm, the same query data is transmitted again to the same group Gm and a response is obtained. However, if no response is obtained, the group moves on to the next group.

In this way, if the mobile station constantly sends questions and answers to the fixed station group in a polling format, effective data exchange communication with good quality and high effective transmission rate can be achieved as described above.

[Brief explanation of drawings]

FIG. 1 is a diagram of an example of a communication system embodying the present invention, FIGS. 2 and 3 are block diagrams of example circuit configurations of transmitting/receiving devices of a mobile station and a fixed station, respectively, and FIG. 4 is a circuit of a central control unit of a fixed station. A block diagram of a configuration example, FIG. 5 is a flowchart of error correction, and FIG. 6 is a data format for transmission and reception. 1.24, 25, 26, 27...Input interface, 2, 12, 18, 23, 28, 2
9. 30...Memory, 3...Address code transmitter, 4゜22...Error correction code addition unit (Ept
+ ) (Ept2), 5.17...control unit,
6, 21...Modulation section, 7゜20...Transmission section (transmitter), 8, 14...Reception section, 9.1
5... Demodulator, 10, 16... Control signal detection unit, 11, 32... Error correction unit, 13,
19° 33... Output section, 31... Synchronization detection section, 34... Error counter section, 35...
...Transmission control section.

Claims (1)

[Claims] 1. Transmit data in the form of a pre-arranged question from a mobile station via radio transmission to a plurality of fixed station groups distributed in the floor area and divided into groups, in order for each group,
When performing polling-type communication to obtain response data from the most suitable station in the group, each fixed station belonging to the group to which a mobile station has asked a specified question transmits the simultaneously received question data to one location over its own high-quality line. The central controller performs error correction and collation on the received data to obtain optimal data, and compares this optimal data with the received data from each of the above fixed stations to select the fixed station with the least transmission errors. A polling communication method from a mobile station to a fixed station is characterized in that the detected fixed station transmits response data to the inquiry data.