JPS61274433A - Polling system for supervisory information - Google Patents

Abstract

PURPOSE:To speed up the collection of supervisory information by sending out the supervisory information, when a signal, the broadcasting mode of which is regulated in advance, sent from a master station is received, in such a way that each slave station is responded with the signal and sends the information after the different time lapse regulated in advance not so as to be interfered with each other. CONSTITUTION:The master station sends out a polling signal which requests a report regarding the supervisory information with the broadcasting mode to all of the slave stations. Each of the slave stations A, B, C, D... sends out a burst signal which reports the supervisory information of own station in a time slot after the time lapse regulated in advance for each station. A delay time for each slave station is set as different shifting by one time slot and reporting signals are transmitted continuously to the master station without colliding. Also, it is constituted that, when each slave station receives the polling signal, all transmissions except the reporting of the supervisory information assigned are prohibited for a regulated time (the time until the reporting from all of the slave stations is completed) and the occurrence of collision between a call requesting signal from another station and the reporting signal is prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a monitoring information polling method, and particularly in a star communication system such as a 5CPC method operated by a demand-assigned connection (DAMA) method, a centralized control master station is used. The present invention relates to a monitoring information polling method in which a control line collects monitoring information for monitoring the status of each slave station.

[Prior art]

As an effective means of communication between a large number of points scattered over a wide area with low communication volume, for example, multiple communication channels of the 5 CPC system are commonly owned by many stations, and a centrally controlled master station can communicate with each station in response to requests. There is a DAMA satellite communication system that allocates communication paths.

In such systems, communication necessary for system operation such as call path assignment is often performed using digital signals through a control line, such as when a call is made from the slave station side. To transmit information from the slave station to the master station, a random access method is used in which burst radio waves are sent to the control line whenever a request occurs. Generally, the master station collects the monitoring information necessary for centrally monitoring the status of each slave station from each slave station through this control line, but in the past, the master station designated one slave station and sent a polling signal. , a polling method is used in which the monitoring information from the responding slave station is checked and the same operation is repeated for the next slave station.

[Problems to be solved by the invention]

However, when collecting monitoring information using the conventional polling method described above, the master station repeatedly sends an instruction signal requesting a report to each slave station and receives a report signal from the slave stations, so it takes time to collect the information. However, there is a drawback that the time required for dedicating the control line for sending out the instruction signal becomes longer. In addition, since no information is transmitted to other slave stations other than the slave station that was requested to report, there is a situation where the report signal collides with the call request signal from other slave stations and requires retransmission. The disadvantage is that the occurrence of is unavoidable. SUMMARY OF THE INVENTION An object of the present invention is to provide a monitoring information polling method that eliminates the above-mentioned drawbacks, allows quick collection of monitoring information, and allows efficient use of control lines.

[Means to solve the problem]

The monitoring information polling method of the present invention is a satellite communication system using a request assignment connection method in which one master station controls a plurality of slave stations, and the master station collects monitoring information of each slave station using a control line. 2, when the control line is a time division multiple access data line of a random access type in which each slave station transmits a burst signal of a predetermined bit length whenever necessary, from the master station. When receiving a predetermined signal of the transmitted broadcast mode, each of the slave stations responds to the signal and transmits the monitoring information after a predetermined time has elapsed so as not to interfere with each other. It is composed of

〔Example〕

Next, the present invention will be explained in detail by way of examples with reference to the drawings. Figure 1 shows part 5 of the present invention! Timing diagrams illustrating the time relationship of data transmission and reception in the example, FIGS. 2(a) and (b)
) is a data configuration diagram of an embodiment of the present invention, and FIG. 3 is a timing diagram of a conventional system. The satellite communication system to which the present invention is applied is, for example, a centralized control lscPc-DAMA system, and the control information from the master station to each slave station is shown in FIG.
), one frame is sent in TDM format as shown in the preamble section (2 people) 1. Unique word (UW)
2 and a plurality of data slots 3 having a constant word length, each data slot is composed of a slave station address (input D) l:f - evening signal (DT) 5. Each slave station constantly receives the TDM signal from the master station, and detects only the data signal of the data slot whose slave station address is addressed to its own station. On the other hand, information is transmitted from each slave station to the master station at the center of any one of the time slots 6 set based on the unique word from the master station at each slave station, as shown in FIG. 2(b). 2 people, U
It is transmitted using the slotted Aloha method in which a burst signal consisting of W, 7'-ta is sent out whenever necessary. In this method, burst 4M signals sent from multiple slave stations in the same time slot collide, but burst signals sent in different time slots have each burst length shorter than the time slot length so that they do not interfere with each other. It's been revealed. As shown in Figure 8g1, the master station sends out a polling signal in broadcast mode to all slave stations requesting reports of monitoring information. Each slave station that received this polling signal, B, C,
Each station D, -, transmits a burst signal reporting monitoring information of its own station to the master station in a time slot after a predetermined period of time A has elapsed, which is predetermined for each station.

This delay time for each slave station is set to be different by one time slot, and the report signals from each slave station are continuously transmitted to the master station without collision. Furthermore, when each slave station receives this polling signal, it is configured to be prohibited from transmitting anything other than the specified monitoring information report for a certain period of time (until the reports from all slave stations are completed). By doing so, it is possible to prevent a situation in which a call request signal and a report signal from other stations collide with each other.

In contrast, in the conventional method, as shown in Figure 3, the polling signal to each slave station is repeatedly sent and the report signal is received from each slave station, so it takes time to collect monitoring information. Not only this, but the dedicated time of the control line from the master station to the slave stations increases, and since no information is transmitted to other slave stations other than the slave stations that receive the polling signal, these slave stations Collision between the randomly transmitted call request signal and the report signal is unavoidable, and retransmission etc. reduce the efficiency of use of the control line.

In the above explanation, it was stated that all slave stations should report continuously, but if there are a large number of slave stations, it will not be possible to make continuous calls from the slave stations during this period, so all slave stations should be made to report continuously. The system may be divided into several groups, each group may report monitoring information, and a call request signal may be transmitted between reports from each group. When a report is being made from one group, if the slave stations of other groups that are not required to report are also prohibited from transmitting, losses due to collisions can be avoided. Also, in the above explanation, the control line is a slotted Aloha random access line that sends out burst signals at any time in time slots synchronized with the unique word of the master station, but pure Aloha random access without synchronized time slots is used. In the case of a line, the same effect can be obtained by using the same method so that each slave station reports after a certain period of time.

〔Effect of the invention〕

As described above in detail, the monitoring information polling method of the present invention has the effect of quickly collecting monitoring information, and reduces loss due to collision between call request signal and report signal and wasteful retransmission. You can also omit it.

[Brief explanation of drawings]

Figure M1 is a timing diagram explaining the time relationship of data transmission and reception in one embodiment of the present invention, Figures 2 (a) and (b) are data configuration diagrams in one embodiment of the present invention, and Figure 3 is a conventional method. FIG. 1... Preamble section (2 people), 2...
・Unique word (UW), 3...Data slot, 4...Slave station address (AD), 5...
...Data signal (DT), 6...Time slot. Figure 1

Claims (2)

[Claims] (1) In a satellite communication system using a request assignment connection method in which one master station controls a plurality of slave stations, in a monitoring information polling method in which the master station collects monitoring information of each of the slave stations using a control line, the The control line is a random access time division multiple access data line through which each slave station transmits a burst signal of a predetermined bit length whenever necessary, and the broadcast mode transmitted from the master station is predetermined. The monitoring information polling system is characterized in that, upon receiving a signal, each of the slave stations responds to the signal and transmits the monitoring information after different predetermined times have elapsed so as not to interfere with each other. (2) The random access method is a slotted Aloha method in which each slave station transmits the burst signal whenever necessary in any one of a plurality of time slots determined based on the timing signal of the master station. A monitoring information polling method according to claim 1, characterized in that: