JPH0226432A - Data radio communication system - Google Patents

Abstract

PURPOSE:To save power by supplying the power of the receiving part of a data radio machine only in a period to receive a synchronous packet and interrupting the power in the period except it by a discriminating means and a power interrupting means. CONSTITUTION:A data radio machine consists of a reception part 10, a transmission part 11 and a control part 12, the reception part 10 demodulates the synchronous packet transmitted by a central station from a high-frequency signal received by an antenna 13 and when the synchronous packet is received, the control part 12 is informed. The control part 12 has a discriminating means 12a and a power interrupting means 12b, the discriminating means 12 discriminates whether the reception part 10 receives the synchronous packet or not and the power interrupting means 12b interrupts the power of the reception part 10 only in the prescribed period shorter than the fixed period until the next packet is transmitted after the discriminating means 12a discriminates the reception of the synchronous packet. Thus, the power saving effect of the data radio machine is increased.

Description

[Detailed Description of the Invention] [Summary] Regarding a data wireless communication system that performs data wireless communication between a central station and a plurality of data wireless devices as terminal stations, it has been found that the power saving effect is large and the data collection efficiency is improved. The purpose is to have a central station that transmits synchronization packets at a fixed period, and a terminal station that transmits terminal packets to the central station by the transmitter in time slots synchronized with the synchronization packets received by the receiver when there is a transmission request. In a data wireless communication system including a plurality of data radios, each of the plurality of data radios 1 includes a determining means for determining whether or not the receiving section has received the synchronized packet; and power cutoff means for cutting off the power to the receiver for a predetermined period shorter than the predetermined period until the next synchronization packet is transmitted.

The multi-chip circuit saves power by disconnecting the low frequency amplifier when the received radio waves are weak.

[Industrial application field]

The present invention relates to a data wireless communication system, and more particularly to a data wireless communication system that performs data wireless communication between a central station and a plurality of data wireless devices serving as terminal stations.

2. Description of the Related Art Conventionally, there has been a data wireless communication system that performs data wireless communication between a central office and a plurality of data wireless devices using, for example, a time slot method.

In this case, a battery is used as a power source in a dataless #11 device such as an aremeter installed in a place where commercial power is not available, or a dataless am used as a mobile station, so there is a demand for power saving.

[Conventional technology]

For example, in a conventional data radio device in a wireless data communication system, a squelch circuit is provided. In this case, the squelch is canceled not only when the central station transmits, but also when other adjacent data radios transmit, resulting in little power saving effect.

Furthermore, since the time frame of the time slot must be set in consideration of the oven time from the operating state of the squelch to the release of the squelch, there is a problem that the time frame of this time slot becomes large and the data collection efficiency is poor.

The present invention has been made in view of the above points, and an object of the present invention is to provide a data wireless communication system that has a large power saving effect and improves data collection efficiency.

[Means for Solving Problem 11] FIG. 1 shows a basic block diagram of a data radio device applied to the wireless data communication system of the present invention.

In the figure, the data radio includes a receiving section 10, a transmitting section 11,
The control unit 12 includes a control unit 12.

The receiving unit 10 demodulates the synchronization packet transmitted by the central station from the high-frequency signal received by the antenna 13, and notifies the control unit 12 when this synchronization packet is received.

The control section 12 has a determining means 12a and a power cutoff means 12b. The determining means 12a determines whether the receiving unit 10 has received a synchronization packet.

After the determination means 12a determines that a synchronization packet has been received, the power cutoff means 12b shuts off the power to the receiving unit 10 for a predetermined period of 11 shorter than the fixed period until the next synchronization packet is transmitted.

Further, the control unit 12 generates a transmission packet in response to a notification from the reception unit 10 and a transmission request, and the transmission unit 11
control.

The transmitter 11 modulates a transmission packet supplied from the controller 12 in a time slot designated by the controller 12, and transmits the modulated packet from the antenna 13.

[Effect]

In the present invention, the determination means 12a and the power cutoff means 1
2b, power is supplied to the receiving section 10 of the data radio only to the WJra+ that is about to receive the synchronization packet,
Since the above power supply is cut off during other periods, the receiving unit 1
0 power consumption can be significantly reduced. Furthermore, since a squelch circuit is not used, there is no need to expand the time frame of the time slot, improving data collection efficiency.

〔Example〕

FIG. 2 shows a flowchart of the processing executed by the control unit 12.

When the power of the data radio is turned on, execution of this process is started. First, in step 20, initial settings such as timer reset are performed, and the receiving section 10 is supplied with the 'll source to enter the receiving state.

Next, it is determined whether there is a notification that a synchronization packet has been received from the receiving unit 10 (step 21), and if there is no notification, the process moves to step 20. This step 21 corresponds to the determining means 12a.

The central station is as shown in Figure 3 (A) and Figure 4 (A), respectively.
For example, a synchronization packet (the shaded area in the figure) is sent out at a constant cycle of about one minute.

If there is a notification of reception of a synchronous packet in step 21, the process proceeds to step 22, where the power to the receiving section 10 is cut off and a timer is started as shown in FIG. 3(B). After this, it is determined whether a packet to be transmitted is generated or not (step 23). If there is a packet to be transmitted, the timer is set to the time slot of the own time slot, for example, as shown in FIG. 3(C).
When the own time slot Tt shown in the shaded area is shown, the terminal station transmits it as a packet (step 24). Power is supplied to the transmitter 11 only when step 24 is executed.

After executing step 24, or if there are no packets to be transmitted in step 23, a timer determines whether the transmission period has ended in step 25, and when the transmission period has ended, the process proceeds to step 26, where the receiving unit 10 Supplies power to the device and resets the timer. After this, the process moves to step 21. Note that the power source of the receiving section 10 is the third
As shown in Figure (B), 11m is set using a timer so that it is cut off after the reception guard time Δt has elapsed when the reception of the synchronization packet ends, and is supplied by the reception guard time Δt before the start of reception of the synchronization packet. Ru. On the other hand, the power to the receiving section of the central station is supplied and cut off at the timing shown in FIG. 3(D).

The above steps 22, 25, and 26 are the power cutoff means 12b.
corresponds to

In addition, in Fig. 3 (C), in the first cycle there is a packet to be transmitted and the terminal station packet is transmitted in its own time slot Ti, but in the second cycle there is no packet to be transmitted and the terminal station packet is transmitted in its own time slot Ti. Ti is not transmitting terminal packets.

In this way, the data radio device is supplied with power only during the period when it is trying to receive a synchronization packet, and the power is cut off during the other 11 periods, so the power consumption of the receiving section 10 can be greatly reduced, and furthermore, the power consumption can be reduced. The risk of malfunction due to this is also reduced.

By the way, after the terminal station packet is received in its own time slot Ti of the first period as shown in FIG. 4(C), the transmission period ends and the receiving unit 10 is powered on as shown in FIG. 4(B). supply After this, if the receiving unit 10 fails to receive the second period synchronization packet, steps 20 and 21 are repeated, so power is supplied to the receiving unit 10 until the nth period synchronization packet is received. In this way, when a data radio cannot receive a synchronization packet, it maintains the reception state until it can receive it, so the terminal station is not disconnected from the central station, and as soon as the reception state is restored, synchronization with the central office is resumed. can be removed.

It should be noted that even in the case of an abnormality as described above, the power to the receiving section of the central station is supplied and cut off at the same timing as in the normal case of FIG. 3, as shown in FIG. 4(D).

Note that in the time slot method, each terminal station has a predetermined time frame for its own time slot for transmitting packets, but terminal stations that have packets to transmit can The data wireless communication system of the present invention is also suitable for a random access time slot method in which an arbitrary time slot is selected from among the time slots and a packet is transmitted in the selected time slot, and the data wireless communication method of the present invention is not limited to the above embodiment. .

〔Effect of the invention〕

As described above, according to the data wireless communication system of the present invention, the power saving effect of the data wireless device is large, the life of the battery power supply is extended, the risk of malfunction due to interference waves is reduced, and the data collection efficiency is improved. However, it is extremely useful in practice.

[Brief explanation of the drawing]

Fig. 1 is a principle block diagram of a data radio device applied to the system of the present invention, Fig. 2 is a flowchart of an example of processing executed by the control unit, and Figs. 3 and 4 show normal operation and abnormal operation. This is a timing chart for each period. In the figure, 10 is a receiving section, 11 is a transmitting section, 12 is a control section, 12a is a determining means, 12b is a power cut-off means, 13 is an antenna, and 20 to 26 are steps.

Claims (1)

[Scope of Claims] A central station that transmits synchronization packets at regular intervals, and a transmission unit (11) that transmits synchronization packets at regular intervals, and a transmission unit (11) that transmits synchronization packets at regular intervals when a transmission request is made. In a data wireless communication system comprising a plurality of data radios as terminal stations that transmit terminal packets to a station, each of the plurality of data radios is provided with information indicating whether or not the reception unit (10) has received the synchronization packet. Discrimination means for discriminating (1
2a), after the determining means (12a) determines that the synchronization packet has been received, the receiving unit (10) is powered off for a predetermined period shorter than the fixed period until the next synchronization packet is transmitted; A data wireless communication system comprising: a power cutoff means (12b).