JPH0338140A - Communication control system - Google Patents

Abstract

PURPOSE:To improve the throughput of a communication network by opening a communication path for an outgoing signal and a returning signal when no signal exists in a channel after the return of the returning signal and applying packet communication including plural message packets when the absence of the signal in the channel is consecutive for a packet interval or above. CONSTITUTION:A communication end detection section 70a is constituted of 4 NOR gates 72, a shift register 74, an AND gate 76 and one OR gate 78, the NOR gate 72 takes OR between a signal from an input port and a signal from an output port 30 and the shift register 74 detects the end of communication based on the time by a communication end detection time constant. The 4-input OR gate 78 informs to a sequence control section 90 that there is a finished communication among communication whose communication path is fixed or 1st outgoing signal from a first coming input channel is interrupted. Thus, an end control section 70 identifies that both of two input channels included in the communication with fixed communication path have no signal as the end of communication.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a communication control system in a node device of an amorphous communication network.

[Prior Art] The present applicant has filed a patent application No. 61-218026 for a node device for an amorphous communication network. This irregularly connected node device includes a plurality of channels including input ports and output ports that respectively connect reception lines and transmission lines to other node devices or terminals. Each input channel is connected to other free output channels in a standby state. Setting and opening of the communication path of the node device will be explained below.

When the outgoing signal of the first packet sent from the originating terminal arrives, the node device detects the first input channel,
The input channel and output channel are disconnected and the outgoing signal is transferred to another free output channel. Other notebook devices that have received this outgoing signal send back an active signal. The transfer source node device starts time-limited monitoring using an active signal detection time constant and detects the arrival of an active signal. Channels that do not return an active signal are considered down and excluded from communication.

Next, time-limited monitoring using the input signal detection time constant is started, and if the first outgoing signal from the same transmission source or another first outgoing signal from another transmission source arrives during this period, Detects a collision and stores channels without collision. In the case of half-duplex communication, the terminal response monitoring time limit is set at the first
It starts when the transfer of the th outgoing signal is completed. In addition, in full-duplex communication, when the receiving terminal detects its own station address while sending the first outgoing signal and returns the first incoming signal, the first
The terminal response monitoring time period starts from the transfer of the th outgoing signal. Within this time period, the node device receives an ACK from the terminating terminal on the input channel for which there was no collision during the input signal detection period mentioned above.
When a signal, that is, the first demodulated signal arrives, connect this channel to the input/output channel of the first input channel,
Set communication route.

The end of communication is determined by time limit monitoring using a communication end detection time constant, and if a state in which there is no signal on the human output channel of the communication path continues for more than the communication end time limit, the communication path is deemed to have ended and the communication path is released. In packet communication, multiple message packets are sent after the first outgoing signal and incoming signal, so this communication end detection time constant is set to the maximum interval between packets, and the time constant for detecting the end of communication is set to the maximum interval between packets to detect multiple frames of packets included in the communication. transmission is possible.

[Problems to be Solved by the Invention] In conventional amorphous communication networks, the time constant for detecting the end of communication is set to the packet interval. For this reason, if the packet interval is large, there will be a long period of no communication during the communication time, resulting in a reduction in the throughput of the node device, and there are disadvantages in that it is not possible to interrupt a communicating terminal from another terminal.

It is an object of the present invention to eliminate such drawbacks of the prior art and to provide a communication network control method for an amorphous communication network that terminates packet communication with a set of outgoing and incoming signals and opens one communication path. do.

[Means for Solving the Problems] According to the present invention, there is provided a communication control method for a node device in an amorphous communication network, which includes a plurality of channels to a terminal or another node device, and a connection means for connecting the channels. When an outgoing signal arrives at the input channel, the first channel is selected, the connection means is controlled, the outgoing signal is transferred to all other available output channels, and the outgoing signal is sent back from the terminal that received the outgoing signal. In a node device that has connection control means that connects the channel on which the received signal has arrived and the earliest channel and fixes the communication route, a response monitoring time limit is started by forwarding the outgoing signal, and if the incoming signal is not received within the time limit, the communication is started. It is started when it is determined that the communication has ended and a return signal is returned, and the communication path is opened as soon as there are no signals on the input channel and the output channel.

[Function 1] According to the present invention, in a node device of an amorphous communication network,
After the return signal is returned, a first communication termination time limit is provided to monitor the state in which there is no signal on the channel, and a second communication termination time limit is provided to monitor that the state in which there is no signal in the channel continues for the packet interval or more. The forward signal and the backward signal are used to perform packet communication that opens a communication path, and the latter is used to perform packet communication including a plurality of message packets, thereby enabling two-mode communication.

The present invention will be specifically described below based on examples. According to the communication control method of the present invention, in a notebook device of an amorphous communication network, a communication path is opened when the first outgoing signal from the originating terminal and the first incoming signal from the receiving terminal are transmitted.

FIG. 3 shows an example of the configuration of an amorphous communication network to which the present invention is applied. The node devices IO are connected two-dimensionally or three-dimensionally by the transmission path 12 to form a grid-like communication network, but the network structure is essentially amorphous, and may have other forms such as linear or loop-like. It's 6 good. In the illustrated example, each node device IO has eight sets of channels, and each channel is connected to other node devices or terminals via a transmission path 12 consisting of a transmitting/receiving line. The terminal 14 is a terminal device that sends and receives data asynchronously, and includes a computer system port, file station, print station, etc. Advantageously, a method is used in which a terminal sends out a response signal immediately upon receiving an incoming signal addressed to the terminal. The transmission line 12 is, for example, a transmission line such as an optical fiber, a coaxial cable, or a twisted wire, and transmits analog or digital signals in full duplex. The transmission path between the node device IO and the terminal 14 may be of a half-duplex format.

Referring to FIG. 1, the node device IO has eight sets of channels, the receiving line of each input channel is connected to the input port 20, and the transmitting line of each output channel is connected to the output port 30. The switching gate section 40 is a gate circuit that selectively connects any input channel to any output channel. The input port 20 also has a control gate section (C
GU) 50 to a start control unit fsAll 60 and an end control unit (EAU) 70. The control gate 50 sends the signal from the input port 20 to the start control section 60 and also sends the signal from the input port 20 to the start control section 60 and the fault storage section (DMUI).
210 and the termination control section 70 to appropriately connect and control the control signals from the switching gate section 40 and the termination control section 70. The start control unit 60 is a functional unit that identifies the input channel to which the input signal arrived first, and also detects whether or not there is an input signal in each input channel. The termination control unit 7a is a circuit that detects that there is no longer an input signal in the input channel of the communication route that has already been set, and performs termination processing of the communication. Switching gate section 40. Start control section 60 and end control section 7
0 are interconnected by a gate set bus 80.

The switching gate unit 40 also includes an active signal sending unit (AFU) 20 for sending out active signals.
0 is connected, which is also connected to the start control section 60. Also connected to the start control section 61 and the termination control section 70 is a failure storage section 210 that stores a channel in which a failure has occurred. The fault storage unit 210 is connected to the gate set bus 80
is also connected. Switching gate section 40, connection gate section 50, start control section 60, end control section 70. The active signal sending unit 200 and the failure storage unit 210 are connected to a sequence control unit (S) that controls the entire device including them.
(:U) Controlled by 90.

The 5CU90 starts the sequence by inputting an outgoing signal to the input port, and has an active signal detection time constant for detecting the return of an active signal, an input detection time constant for detecting a collision, and a terminal response monitoring time for detecting a response from the receiving terminal. This is a circuit that controls the operation of a node device by time-limited monitoring using constants and the like.

As shown in the case of 4 channels in FIG.
It is composed of. The communication end detection section 70a is configured by four NOR gates 72, a shift register 74, an AND gate 76, J, and one OR gate 78 connected as shown. NOR gate 72 logically ORs the signal from the input port and the signal from output port 30. The shift register 74 is a circuit for detecting the end of communication based on a time determined by a communication end detection time constant, which will be described later.

The AND gate 76 is a circuit that performs a logical product of the output of the shift register 74 and the output of the control gate unit 50.

The 4-input OR gate 78 is a circuit that notifies the sequence control unit 90 that there is a communication that has ended among the communications with a fixed communication path, or that the first outgoing signal from the first input channel has been interrupted. The selection of which information to report is made by the control and gate unit 50. As will be explained below, in the end control unit 70, when there is no signal from both of the two input channels included in communication with a fixed communication path, it is determined that the communication has ended.

The end of communication is identified by a state in which there is no signal or by a predetermined logic state continuing for a time determined by a communication end detection time constant. The "communication end detection time constant" is a tie-out time constant of the shift register 74, and two values can be selected by switching before the switch S. When the front switch S is OFF, a low frequency clock CKo is supplied to the shift register 74 via the ANDNO gate 72R gate 106, and its timeout time length is set to the maximum interval between packets. In this case, the node device allows a plurality of series of message packets to pass through. When the front switch S is ON, the high frequency clock CKI is applied to the AND gate 104. The timeout period is provided through an OR gate 106, and the timeout period is set to a period long enough to detect the absence of a signal on the channel. When using the Manchester code, since the state of "0" or "l" does not continue for three or more bits, the time is set to a length of three bits. Specifically, the transmission speed is 1MbPs
In this case, it is set to 3 μs, and the end of communication is detected in this time. In this case, the node device allows passage of one set of packets of outbound and inbound signals. In this actual travel example, the 6-connection storage unit 70b with the switch SW in the on state includes four flip-flops 71 for storing channels whose communication paths are fixed, and for controlling writing and erasing of the memory. The AND gate 73 and a bus buffer 75 for controlling connection of the output to the gate set bus 80 are connected as shown in the figure.

With this configuration, the shift register 74 is always in a state where it can detect the end of communication for all channels. In other words, since the end of communication can be detected for channels that are not selected by the control gate section 50, when switching is performed, there is no delay corresponding to the communication end detection time constant in detecting the end of communication.

Further, the time constant for detecting the end of one communication may be set depending on the case of full-duplex communication and the case of including both full-duplex communication and half-duplex communication. Therefore, there is no need to change the hardware of the device itself.

Note that instead of these four NOR gates 72, four NOR gates 72 are used.
By providing an AND gate, the input channel and the output channel can be logically ANDed. In this way, the end control unit 70 identifies the end of the communication when there is no signal in either of the two high-power channels included in the communication with the fixed communication route.

Next, communication control in the node device will be explained.

As shown in FIG. 4, in half-duplex communication, packets are transmitted serially. When the originating terminal sends out the first packet a, the node device detects the first arrival channel on which the packet a arrived and transfers it to another free output channel. Packet a includes a preamble P, a destination terminal number, a local terminal number, and a check area C1 end code E at the rear of the message M. The node device detects active signals and collisions by time monitoring of an active detection constant and an input signal detection constant.

When the transfer of packet a is completed, time monitoring of the terminal response monitoring constant is started, and when the first response packet b arrives from the receiving terminal, this channel is connected to the input/output channel of the first input channel, and the communication route is fixed. . Packet b is transmitted through this communication path (reaches terminal 8. When the node device finishes detecting packet a, it starts dimension monitoring using the terminal response monitoring constant, detects the end of communication using the communication end detection time constant, Fix the communication path.

If the originating terminal continues the communication, it sends out the second message packet C and performs the same communication procedure as the first one. FIG. 5 shows an example of full-duplex communication. While the originating terminal is transmitting the first response packet e, the receiving terminal returns the first response packet f. The node device starts time monitoring using a communication termination constant, detects that there is no signal from the human output channel, and opens the communication path. In the case of Manchester code, the communication end time is 3
Set to bit length. If communication continues, the second
Communication is performed using the second message packet and response packet.

As described above, in this embodiment, a communication path is set and opened for each pair of message packet and response packet.

[Effects of the Invention] According to the present invention, the no-signal time in the communication path is extremely shortened, and the throughput of the communication network can be improved. Packet rif in communication! You can receive incoming calls from other terminals at the same time, improving communication efficiency.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram of a node device showing an embodiment of the communication control method according to the present invention, FIG. 2 is an example of a circuit configuration of a termination control section, and FIG. 3 is a relay system diagram showing an example of a configuration of an amorphous communication network. FIG. 4 is an explanatory diagram of half-duplex communication according to the present invention, and FIG. 5 is an explanatory diagram of full-duplex communication according to the present invention. Description of C''' Node device Switching gate section Control gate section Start control section End control section Sequence control section Fault storage section Input channel Output channel 0 0 50° 60° 70. 90° 10 i0 ~ 17° 01 ~ 07゜

Claims (1)

[Scope of Claims] 1. A communication control system for a node device in an amorphous communication network, which includes a plurality of channels to a terminal or other node devices, a connection means for connecting the channels, and a communication control method for an input channel. When the signal arrives, it selects the earliest channel, controls the connection means, transfers the outgoing signal to all other available output channels, and receives the incoming signal returned from the terminal that received the outgoing signal. In a node device having connection control means for connecting a channel and the earliest channel and fixing a communication path, a response monitoring time limit is started by transferring the outgoing signal, and if the incoming signal is not received within the time limit, communication is started. A communication control method characterized in that the return signal is determined to be terminated, the return signal is returned, and when the signal disappears, a communication termination monitoring time limit is started, and the communication path is opened immediately when the signal disappears from the input channel and the output channel. 2. In the node device according to claim 1, the first communication end time limit monitoring starts when the return signal is returned and monitors the state where there is no signal on the channel; and the state where there is no signal on the channel. , a second communication time limit monitor that monitors whether the communication is continued for a period longer than the packet interval, and a selection means that selects the first and second communication end time limit monitors, the first and second communication ends. A communication control method that determines the end of communication based on a time limit.