JPH084246B2 - Communication control method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a communication control method, and more particularly to a high efficiency communication control method suitable for sanitary communication and the like.

[Background of the Invention] Conventionally, for example, like a reservation-type non-collision multiple access protocol such as the Ministry of Posts and Telecommunications, allocation of slots is determined based on information of reservation slots, and this is sent to each node as control data. The data was sent to the slot assigned by the control data. However, no consideration is given to performing non-contention reservation and contention data transmission at the same time when no other reservation is confirmed.

[Object of the Invention]

An object of the present invention is to provide a communication control method that enables communication with good responsiveness and high throughput in a broadcast communication channel with a long propagation delay.

[Outline of Invention]

If information is reserved and then sent, the transmission is delayed by the propagation delay time. Therefore, according to the present invention, by adding the data to be sent to the reservation information and transmitting the information, if there is no other node to be transmitted at the same time, the propagation is performed. The feature is that transmission is possible without delay. A more detailed description is as follows. Each node in the communication system has a reservation queue that holds reservation information from other nodes,
A communication control method for controlling communication that enables multiple access of a communication path by using a frame including one or more reservation units for transmitting reservation information and zero or more data units for transmitting data, When the reservation queue of the preceding node is empty, the transmission source node transmits the data together with the reservation information by the reservation unit and the data unit. According to the present invention, even if two stations compete with each other, only the reservation information can be sent, so that there is an advantage that the recovery can be performed immediately and surely.

Example of Invention

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of the overall configuration of a communication system to which the present invention is applied. In the figure, 1, 11 and 12 are each node in the communication system, and 2 is a repeater which mediates communication. Specifically, this system is a satellite communication system in which 2 are hygiene and 1,11,12 are ground stations (stations, stations),
The communication is performed, for example, by returning the radio wave sent from the station 1 to the stations 1, 11 and 12 by the repeater (hygiene) 2. The radio waves transmitted from the stations 11 and 12 are similarly transmitted to other stations.

FIG. 2 shows an example of the format of the transmission frame 3 used in the communication system. The frame 3 is used for transmitting the synchronization burst 4 for synchronizing the frames and the reservation information. It comprises a reservation section 5 and a data section 6 used for transmitting data, and the reservation section 5 and the data section 6 respectively consist of prefix words 51, 61 and main body sections 52, 62.

Figure 3 shows the stations 1,11,1 in the above system.
2 shows a configuration diagram of 2. Station 1 (or 11,12)
From an antenna 100, a transceiver interface 110 that performs frequency conversion, a multiplex communication control device 120 that executes the control of the present invention, and a data source (interface) 130 that interfaces with a host computer or terminal station. Become.

FIG. 4 shows a multiplex communication control device 120 relating to the control of the present invention.
FIG. 13 is a configuration explanatory diagram of 130, 130 is a receiving unit for receiving communication data, 131 is a receiving queue for received communication data, 140 is a transmitting unit, and 170 is a packet 17 which is communication data.
Show send queue for 1. Further, 190 is a frame configuration that holds the frame configuration or attributes such as whether or not the data section allows conflicting access, 150 is a reservation queue that holds reservation information from all nodes, and 165 is a conflict within the same conflict frame. The contention counter 165 that holds the number of packets 171 that have been created is shown.

181 is the current time, reservations and history of conflicts and errors, differentiation,
A situation information collection device capable of collecting statistics, creating information necessary for frame configuration control, confirming this information to all stations by the reservation unit 5, and adjusting by a majority vote, 180 is a frame information collection device based on this information. The frame configuration control device determines the length, the number, and the position of the reservation unit 5 and the data unit 6.
When performing distributed control, the operating mechanisms of both devices 180 and 181 are common to all nodes.

The communication control method of the present invention comprises access processing of multiple communication paths and processing of reservation information as a base for the access processing.
Hereinafter, the time division and distributed control will be described as an example.

FIG. 5 shows a communication path access process common to each station 1. First, check whether or not the reserved section 5 assigned to the own station 1 (block 500), and if so, in order to reserve the data section 6 necessary for transmitting the unreserved packet 171 in the transmission queue 170. Information is transmitted using the reservation unit 5 (block 505). If not, check whether it is time to access the data section 6 (block 510), and if possible, select the first packet 171 in the transmission queue 170 that is not being transmitted (block 515).
If there is such a packet 171 (denoted as M), it is determined whether the accessed frame 3 is a conflict frame or not.
Check using 190 (block 520). If it is a conflict frame, the packet M is determined to be in conflict and being transmitted (block 525). If it is not a conflict frame, the reservation queue 150 is used to check whether the data section 6 to be accessed is reserved for packet transmission of the own station 1 (block 530). If it has been reserved, it is determined that the selected packet M is being transmitted (block 535). After that, and after the block 525, the packet M is transmitted.
When the value of the contention counter 165 is a certain value or more, or when the transmission data amount of the local station in the contention frame is large, the process of the blocks 525 and 540 may not be performed when the block 520 determines that the contention frame is present.

If it is determined in block 510 that the data section 6 is not being accessed, the data source 130 checks if a new transmission request for the packet 171 has occurred (block 550), and if so, a new packet 171 is placed in the transmission queue 170 ( Block 555). If not, check whether frame 3 currently being accessed has ended (block 56
0) If so, change the frame information 190 so that the information of the next frame becomes the information of the current frame, and the information of the next frame becomes the information of the next frame .... In addition, information such as time information, reservation and error history, differentiation, and statistics collected by the situation information collection device 181, and a reservation queue 170
Information created by the frame configuration control device 180 based on whether or not it is a competing frame or information transmitted by the reservation unit 5 and confirmed by a majority decision or the like. Change and set the configuration, number and length of 6 (block 565).

FIG. 6 shows the processing of the reservation information which is the basis for the above-mentioned communication path access. It should be noted that this process is common to each station 1.

First, check whether the reservation section 5 has been received (block 600). If so, the reservation information creation process is performed based on this (block 700). If not, check whether the data section 6 has been received (block 605), and if so, check whether there is a conflict (block 61).
0). If there is a conflict, 1 is added to the conflict counter 165 (block 615), and it is checked whether the packet originated from its own station by checking the transmission time of the packet in transmission of the transmitting queue 170 (block 620). If it originates from its own station, it releases the conflicting state during transmission of the packet 171 (block 625). If it is found that there is no competition in the check of block 610, the check is made as to whether the packet is the packet addressed to the own station (block 630).
If it is a packet addressed to your own station, perform its reception processing (block 63
Five). If not, check whether it is a packet originated from the local station (block 640), and if the packet originated from the local station, delete the packet 171 from the transmission queue 170 (block 650).

FIG. 7 shows the contents of the reservation information creation process (block 700). First, whether the received frame 3 to which the reservation unit 5 belongs is a competitive frame or whether it is adjacent thereto, frame information,
Check using 190 (block 705) and if so, check whether there is a competing packet from the reservation unit 5 received (block 710). If there is, the state during transmission of this packet 171 is released (block 720). After this, and block 705, block 71
When the condition of 0 is not satisfied, the received packet reserved by the reservation unit 5 (is transmitted to all stations) is put in the reservation queue (block 30) and the frame information creation process (block 800) is performed.

FIG. 8 shows the contents of the frame information creation process (block 800).

First, check whether the reservation queue 150 is connected (block 805). If it is not empty, the total length of the body of each data part of the next frame is set so that it becomes equal to the total length of the packets in the reserved queue 150 (at this time, except for contention transmission). Set the length of (block
810). However, the frame length has an appropriate upper limit for synchronization and other reasons. If you are accessing a conflict frame,
It is ended and the competition counter 165 is set to zero. (Block 815). However, it is possible to make a modification so that the packets are reserved so that they can be distinguished from each other during competitive transmission, and if the reservation queue 150 is not 0, only this processing is performed if only reserved transmission is in progress.

The time required for the data to make a round trip between the station 1 and the repeater 2 is the propagation time τ, and it is checked whether the next frame length 1 is smaller than τ (block 820). If l <τ, the next frame is regarded as a competitive frame (block 83).
0). After this, if the time τ-1 before the scheduled access start of the next frame is after the current time, a modified embodiment in which the reservation unit 5 is inserted at the former time is also possible.

 According to the above embodiment, there are the following effects.

(1) Since the control is performed in a distributed manner at each station instead of the centralized control, there is no response delay or overhead due to control data transmission from the control station. Further, no inconvenience due to an error in the control station or control data does not occur. Therefore, high reliability and high efficiency can be secured.

(2) Since the contention frame and the normal reservation type frame are separated, the control is simple and the reliability is high.

(3) Since the reservation unit 5 is assigned to all stations and there is no conflict, the control information to be confirmed can be transmitted to all stations. Therefore, the reliability of distributed control can be improved.

In the above embodiment, when the reserved queue 150 is changed to empty, the currently accessed frame 3 is set as the conflict frame, and the reservation unit 5 and the data unit 6 are accessed according to the configuration of the conflict frame. Good.

〔The invention's effect〕

As is clear from the above description, according to the present invention, the unreserved band can be used immediately and the reserved band can be used without conflict. Also, when using an unreserved band, it is possible to reserve using the reserved band at the same time, so when the contention is found to occur, the reserved band can be used immediately for transmission, causing a conflict again. It does not increase the line load and lower the responsiveness.

[Brief description of drawings]

1 is a block diagram showing an example of a communication system to which the present invention is applied, FIG. 2 is a diagram showing a format of a communication frame, FIG. 3 is a block diagram of a ground station 1, and FIG. 4 is multiplex communication control. FIG. 5 and FIG. 8 showing the configuration of the apparatus show a flow chart of the control method performed by the communication control apparatus. 1 ... station (station, ground station, node), 3 ... frame, 5 ... reservation section, 6 ... data section, 150 ... reservation queue, 190 ... frame information, 120 ... multiplex communication control device.

Claims (4)

[Claims] 1. Each node in a communication system has a reservation queue for holding reservation information from another node, and one or more reservation units for transmitting the reservation information, and for transmitting the data. In a communication control method for controlling communication that enables multiple access of a communication path by using a frame consisting of 0 or more data parts, when the reservation queue of a destination node is empty, the reservation is performed from the source node. A communication control method, wherein the data is transmitted by the data unit together with the reservation information by the unit. 2. The communication control method according to claim 1, wherein the usage allocation of the reservation unit that can be used by each node is fixed. 3. The communication control method according to claim 1, wherein, when the reservation amount is less than or equal to the capacity of the data part according to the reservation information, the capacity of the data part of the next frame is set to the reservation amount. A communication control method characterized by equalization. 4. The communication control method according to claim 3, wherein when the length of the next frame is shorter than the data propagation time τ between nodes, the access time of the reservation unit of the next frame is −τ.
A communication control method that inserts a reserved part only before.