JPH02266726A - Radio receive supervisory method - Google Patents

Abstract

PURPOSE:To shorten a period from the occurrence of a fault to the detection of the fault by setting a test signal time slot in a radio frame, and transmitting a burst signal for test with the test signal time slot in the radio frame by a slave station. CONSTITUTION:A polling time slot and the test signal time slot are set on the radio frame, and the reception station of an up line i.e., a master station 1 or a relay station 22 controls the transmission operation of the burst signal for test at the time position of the test signal time slot for the slave station. In other words, the slave station transmits the burst signal for test to the master station 1 or the relay station 22 at every radio frame by using the test signal time slot, and the master station 1 and the relay station 2 supervises the reception level or the information content of the burst signal for test from the slave station, and judges reception abnormality when detecting no burst signal for test in the period exceeding over that of the radio frame. In such a way, it is possible to shorter the period from the occurrence of the fault to the detection of the fault.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention performs communication control using a demand assignment method that allocates a wireless communication channel between a slave station and a master station only when a call occurs to the slave station. The present invention relates to a wireless receiving device monitoring method for monitoring whether a failure occurs in an uplink wireless receiving device in a multidirectional multiplex communication system.

(Prior Art) As is well known, in a multidirectional multiplex communication system, a 1:N ratio is established between one master station and a plurality of slave stations that are geographically separated and scattered around the master station. It is a time division multiplex wireless communication system that performs communications, and depending on the system scale, one or more relay stations may be installed.

FIG. 2 shows a configuration example of this type of multidirectional multiplex communication system, in which a plurality of slave stations (21, 23, 24, 25, . . . 2,
) among the slave stations 23 and 24 are connected to the remaining slave stations 21 + 25 . ..., same 2. shows an example of a system that is directly connected wirelessly to a master station.

By the way, in a multidirectional multiplex communication system that adopts a demand assignment method from the viewpoint of effective use of wireless communication channels, slave stations stop transmitting radio waves except when transmitting information to increase the usage time of other slave stations. I try to aim for it, but
Since there are slave stations that stop transmitting, the uplink receiving station (i.e., the master station or relay station) performs radio reception to determine whether the problem is due to the radio reception device of the own station. It is necessary to monitor whether or not a device failure has occurred. Therefore, conventionally, attention has been paid to the fact that the master station has a polling function that calls any one slave station and invites it to transmit, and monitors the radio receiving apparatus as shown in FIG. 3, for example.

That is, as shown in FIG. 3(a), the master station 1 sequentially inserts the polling signal 21 to the same pH into one polling time slot provided in each consecutive radio frame period, and the slave stations 2M, Same 25-2. ．． A call is made to the relay station 22 in order. Slave station 2h 25~2
．． , the relay station 22 directly receives and detects the polling signal and immediately transmits its own station information to the master station. In addition, slave station 23
．． 24 is transmitted via the relay station 22 with a polling signal P3. P4 is detected, and as shown in FIG. 3(b), the station information P'3 of the own station is immediately detected. The same P'4 is transmitted to the relay station 22.

In other words, the station information signal is always transmitted from the slave station to the uplink of the master station l and the relay station 22 at least once within the polling period 'rp, even if no call occurs to the slave station. The uplink wireless receiving device that receives signals from the slave stations of the station 1 and the relay station 22 monitors the received electric field, and when this signal is not detected for a period longer than the polling period TP, it is determined that there is a failure in the receiving device. The line is switched to the backup receiving device.

(Problems to be Solved by the Invention) However, the above-described conventional monitoring method for a radio receiving device has a problem in that it takes a long time from the occurrence of a fault to its detection and lacks promptness.

For example, as shown in FIG. 3(c), at time 1=1° after receiving station information P'3 and P- of slave stations 23 and 24, there is a failure in the uplink side receiving device of relay station 22. Even if it occurs, it can be detected at time t=t2 after the reception timing of station information P''3゜P''4 in the next polling cycle, as shown in Fig. 3(d), and it can be detected from the time when the failure occurs. Delay time longer than polling cycle TP until detection (τ1=tz tx
) is required.

Since polling is applied to one slave station in one radio frame, one polling period TP becomes a considerably long period depending on the number of slave stations, and switching to the standby system is not possible during this period.

Since it is undesirable for system operation if the communication between the master station and the slave station continues for a long period of time, improvements are desired.

The present invention has been devised in view of these conventional problems, and an object of the present invention is to provide a method for monitoring a radio receiving device that can significantly shorten the period from the occurrence of a fault to its detection.

(Means for Solving the Problems) In order to achieve the above object, a method for monitoring a radio receiving device according to the present invention has the following configuration.

That is, the wireless receiving device monitoring method of the present invention provides a multidirectional multiplex communication system in which communication is controlled by a demand assignment method in which a wireless communication channel is allocated between a slave station and a master station only when a call occurs to the slave station. A wireless receiving device monitoring method for monitoring the occurrence of a failure in an uplink wireless receiving device in a wireless receiving station, comprising: setting a test signal time slot in a wireless frame; The designated slave station transmits a test burst signal in the test signal time slot of each radio frame; and the uplink receiving station transmits a test burst signal from the designated specific slave station in its own uplink radio receiving device. It is characterized by: monitoring the reception level or information content of the test burst signal;

(Function) Next, the function of the wireless receiving device monitoring method of the present invention configured as described above will be explained.

An uplink receiving station, that is, a master station or a relay station, specifies a specific subordinate station directly and controls the slave station to transmit a test burst signal in a test signal time slot in each radio frame. do.

Then, the uplink receiving station monitors the received signal level or information content at the time position of the test signal time slot, and if the reception of the test burst signal continues for several frames, the uplink side of the own station monitors the received signal level or information content at the time position of the test signal time slot. It is determined that there is a problem with the receiving device.

Thus, according to the wireless receiving device monitoring method of the present invention,
The delay time from the occurrence of a fault to its detection can be multiple periods of a radio frame.

This period is much shorter than the polling cycle in the conventional method. Therefore, according to the method of the present invention, the period from the occurrence of a fault to its detection can be significantly shortened, and switching to the standby system can be carried out at an early stage, which has the effect of shortening the momentary line interruption time.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a time chart of a method for monitoring a wireless receiving device according to an embodiment of the present invention. In FIG. 1(a), the radio frame TF is provided with a polling time slot P as explained in the conventional example, but in the present invention, a test signal time slot E used only for monitoring is set. .

Then, an uplink receiving station, that is, a master station or a relay station 22
is designed to designate a specific subordinate station directly and control the transmission operation of the test burst signal to that slave station at the time position of the test signal time slot E.

That is, for example, assuming that the master station specifies the slave station 21 and the relay station 22 specifies the slave station 25, the result is shown in FIG. 1(b).

As shown in (c), the slave station 2M transmits a test burst signal E'1 to the master station 1 using the test signal time slot E for each radio frame, and the slave station 23 transmits the test burst signal E'1 to the relay station 22. A test burst signal E' is transmitted.

Here, the test burst signals E', , E' are unmodulated waves or signals modulated with random signals when monitoring the reception level, and specific word identification signals are used when monitoring the information content. use

Note that P' and -P'a in FIGS. 1B and 1C are the station information of the slave station in response to the polling of the master station 1, as shown in the conventional example. That is, the master station 1 polls each slave station as a form of normal communication, not for the purpose of monitoring as shown in the conventional example, and collects station information P'5. The same P',, the same P'1 are slave stations 25. Same 2□ Same 2
The station information P'4 and P'3 are received directly from the slave station 24.1 via the relay station 22. This shows what was received from 23rd.

These station information are received by the master station together with the test burst signal E' for each radio frame, as shown in FIG. 1(b). On the other hand, at the relay station 22, as shown in FIG. 1(C), the test burst signal E') transmitted from the slave station 23
is received for each radio frame, but the station information P'4 and the same P
'3 is received when there is polling, so the timing of these receptions is uncertain, and the reception interval may be quite wide. As mentioned above, the conventional method of monitoring using the polling method had a problem.

Now, the master station 1 and the relay station 2 receive test burst signals from the slave stations. Monitors the reception level or information content in the wireless receiving device of the E line and transmits the wireless frame T.
When the test burst signal is not detected for a period of v or more,
It is determined that there is a reception error.

Here, possible reasons why the test burst signal is not detected include both a failure of the uplink wireless receiving device and a failure of the slave station that is instructed to transmit the test burst signal. Therefore, in master station 1 and relay station 2 It determines that there is a failure and switches the line to the backup receiving side.

For example, as shown in FIG. 1(d), time 1=11 after the reception device on the uplink side of the relay station 22 receives the third test burst signal E'3 counting from the left in the figure.
If a failure occurs in the receiver, the receiving device detects a time t=t3 after the detection timing of the fourth test burst signal E'3 and before the detection timing of the fifth test burst signal E'3. This means that reception abnormality can be detected.

Delay time for abnormality detection in this case (τ1=ts tt)
is about the period of the radio frame TF, and the relay station 2
2 detects an abnormality and instructs the slave station 24 to transmit a test burst signal. As a result, the receiving device on the uplink side of the relay station 22 receives the test burst signal E'4 as shown in FIG.
When test burst signal E'4 is not detected from time 1=1. as shown in FIG. 1(g). It is determined that there is a failure in the receiving device, and the line is switched to the backup receiving system. In this case, the failure detection delay time (τs=t 4 t t) is about 2 to 3 times the radio frame TF. In reality, this failure detection delay time τ3 is set for a plurality of periods of the radio frame T for safety reasons. However, even if this is done, it is clear that the delay time τ3 according to the method of the present invention is much shorter than the delay time τ1 according to the conventional method.

(Effects of the Invention) As described above, according to the wireless receiving device monitoring method of the present invention, the delay time from the occurrence of a failure to its detection can be made into a plurality of periods of a wireless frame. This period is much shorter than the polling cycle in the conventional method.

Therefore, according to the present invention, the period from the occurrence of a fault to its detection can be significantly shortened, and switching to the standby system can be carried out at an early stage, which has the effect of shortening the instantaneous line interruption time.

[Brief explanation of drawings]

FIG. 1 is a time chart of a method for monitoring a radio receiving device according to an embodiment of the present invention, FIG. 2 is a block diagram showing an example of a multidirectional multiplex communication system to which the present invention is applied, and FIG.
The figure is a time chart of the conventional method. l... Master station, 21+ 23.2 a, 2
s~2n...Slave station, 22...Relay station, TF...Radio frame, E...Test signal time slot, E'... ...Test burst signal, P...Polling time slot, P'1 to P゛, ...Station information. Agent Patent attorney Yoshihiro Yahata E'-2- is the first office for meetings P+'~P;+
--One-way tilt] How to monitor Kabutogi Saramoto's fiercely defeated woman in a small outfit Part 1, Part 3

Claims (1)

[Claims] Monitoring the presence or absence of a failure in the uplink wireless receiving device in a multidirectional multiplex communication system where communication is controlled using a demand assignment method that allocates a wireless communication channel between a slave station and a master station only when a call occurs to the slave station. A method for monitoring a radio receiving device is to set a test signal time slot in a radio frame; a slave station designated by an uplink receiving station receives the test signal in each radio frame. transmitting a test burst signal in the time slot; the uplink receiving station monitors the reception level or information content of the test burst signal from the designated specific slave station in its own uplink radio receiving device; A method for monitoring a wireless receiving device, characterized in that: