JPS6327909B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transmission terminal device for a digital network having a packet switching function for making a call by specifying the amount of information to be transmitted per unit time.

In digital networks that transmit by specifying the amount of information to be transmitted, when the exchange detects the occurrence of a call, it determines whether the specified amount of information can be accommodated within the exchange capacity, and if it cannot, it cannot receive the call. A signal is sent back. Conventionally, when an unreceivable signal is returned to a terminal, the terminal automatically re-calls the call, but in times of call congestion, etc., this reduces the throughput of the network due to the back and forth of calling signals. ,
There were also problems with terminals, such as the time it took to connect.

An object of the present invention is to solve the above problem by reducing the specified amount of transmission information and re-calling even if a reception-unreceivable signal is returned.
An object of the present invention is to provide a terminal device for realizing transmission matching the capacity of an exchange.

There are two types of terminals: continuous terminals that always send data at a constant rate, and packet terminals that send a certain amount of data in chunks.The present invention provides a device for each terminal that achieves the above purpose. The present invention is characterized in that the signal transmission rate changing means changes the signal transmission rate sent from the terminal and re-calls based on the unreceivable information detected by the unreceivable detecting means. Furthermore, for packet terminals that send out a single chunk of data at irregular intervals, for a specified amount of information,
A packet signal generating means is provided for transmitting packet signals such that the amount of information transmitted within a certain period of time is the same on average.

Examples will be described below using figures.

FIG. 1 shows an embodiment in a continuous terminal, and in the figure, a received signal coming in from a terminal 1 is input to a reception failure detection circuit 2. In the detection circuit 2, a digital word indicating unreceivable is prepared, and when a part of the received signal matches this, an unreceivable detection signal is output. The unreceivable detection signal is input to the signal transmission speed changing circuit 3. The signal transmission speed changing circuit 3 has a configuration as shown in FIG. 2, and the unreceivable detection signal input from the terminal 9 is
One branch outputs a changed timing signal to the terminal 6 by changing the oscillation frequency of the oscillator 8, and the other is input to the memory 7 as an address. A digital word representing each signal speed is input to the memory 7, and by changing the addressing, a new digital word is output to the terminal 10. The digital word outputted to the terminal 10 is input to the calling device 4, inserted into the signal speed designation portion of the calling signal, and the calling signal is outputted to the terminal 5.

FIG. 3 shows an embodiment in a packet terminal.
In the figure, the received signal coming from terminal 11 is the first
The signal is outputted to the information amount changing circuit 13, which has exactly the same function as the signal transmission rate changing circuit 3 shown in FIG. 1, via the unreceivable detecting circuit 12, which has exactly the same function as the unreceivable detecting circuit 2 shown in the figure. Information amount changing circuit 13
Of the outputs, the digital word is input to a calling circuit 14 having exactly the same function as the calling circuit 4 of FIG. 1, and a calling signal is output. Packet creation circuit 1
5 receives a calling signal output from the calling circuit 14 or an information signal coming from the terminal 17. FIG. 4 is a diagram illustrating the packet creation circuit in detail. In this embodiment, a case will be explained in which the amount of information contained in one packet is constant. In other words, in this case, there is a proportional relationship between the amount of information per unit time and the number of packets, and the number of packets sent is
Packet sending is controlled by comparison with the packet interval to be sent. A call signal received from the terminal 21 or an information signal received from the terminal 17 is changed into a format matching the format of the packet to be sent out by the packetization circuit 27, converted into a packet signal, and temporarily stored in the buffer memory 23. Ru. On the other hand, the timing signal input to terminal 22 is output to counter 2.
The number of signals outputted from the packetizing circuit 27 is also counted by the counter 24, and both output signals are inputted to the comparator 25. The comparator 25 compares the counts of both inputs and outputs a pulse based on the difference in counts. This will be explained in more detail using the timing chart shown in FIG. FIG. 5a shows the signal at the output 27 of the packetizing circuit. FIG. 5b shows the output value of the counter 24 in decimal notation. counter 2
4 is cleared at the beginning of Figure 5,
Each time a packet is output from the packetization circuit 27, the count is incremented by one. On the other hand, the fifth
In figure c the output from terminal 22 is shown. Pulses are sent out at regular intervals determined by the specified amount of information per unit time. In FIG. 5d, the output of the counter 26 is expressed in decimal notation. The counter 26 is also cleared at the beginning of FIG. 5, and counts up each time a pulse is received. FIG. 5e shows the output of the comparator 25. If the output of the counter 26 is larger than the output of the counter 24, a pulse is output from the comparator 25 at the change point of the counter 26, and conversely,
When the output of the counter 26 becomes small, a pulse is output even at the change point of the counter 24. As a result of this output, the packetized signal temporarily stored in the buffer memory 23 is outputted to the terminal 16. By using such means, it is possible to construct a packet terminal that sends out the amount of information per unit time as specified.

In this embodiment, the case where the amount of information included in one packet is constant has been explained, but even if the amount of information is not constant, the generation interval of the timing signal that enters the terminal 22 in FIG. By specifying the length of the amount of information contained in the packet in the incoming information signal, it is possible to generate packets in accordance with the specified amount of information per unit time in the same way. .

Next, the format of the calling signal and calling packet will be described. FIG. 6 shows a timing chart of calling signals in consecutive terminals. FIG. 6a shows the signal sent from the terminal to the exchange, and FIG. 6b shows the signal sent back from the exchange to the terminal. In this example, both signals are sent out before the start of information transmission using a normal information transmission path. In the timing chart of FIG. 6, the signal from the terminal changes from OFF to ON in accordance with the call request. The exchange detects this change and transmits the signal from the exchange.
Change from OFF to ON. Since the device is OFF
When the change to ON is detected, _T1 seconds later, the signal from the terminal is changed from ON to OFF, and after _T2 seconds, a signal for selecting the other terminal is sent in digital form. A signal specifying the speed is sent out in digital form after a further T ₃ seconds after this selection signal ends. T ₄ after the signal specifying the speed ends
If a reception permission signal is returned from the transmission path in the opposite direction within seconds, a connection with the other party is established and information transmission begins. If a reception disable signal is received instead of a reception permission signal, the calling process is repeated again, and only the form of the signal specifying the speed is changed.
In the case of a packet terminal, a call is made using exactly the same process. However, in this case, the signal for calling is also in the form of a packet, the format of which is shown in FIG. In this example, the format of the packet sent from the terminal to the exchange is shown with the first packet on the left. A packet includes a flag indicating the delimiter of the packet, a control section to indicate the type of the packet, a destination specifying section and a source specifying section to indicate the destination and source address, and the amount of information to be sent per unit time. It consists of a speed designation section for displaying information, and a management information section for indicating other management information, each section consisting of a digital word consisting of several bits.

The present invention has the advantage that the configuration described above allows information transmission to be performed that is suitable for the exchangeable capacity of the exchange.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the invention using a continuous terminal, FIG. 2 shows a transmission rate changing circuit used in the invention, and FIG. 3 shows an embodiment of the invention using a packet terminal. FIG. 4 is a diagram showing a packet signal generation circuit in a packet terminal, FIG. 5 is a timing chart showing the operation of a comparator in the packet signal generation circuit, FIG. 6 is a timing chart showing a call signal from a continuous terminal, and FIG. The figure shows the format of a calling packet at a packet terminal. In the figure, 2 and 12 are unreceivable detection records, 3 is a signal transmission speed change circuit, 13 is an information amount change circuit, 4 and 14 are calling circuits, 15 is a packet signal creation circuit, 7 is a memory, and 8 is an oscillator. , 27
is a packetization circuit, 23 is a buffer memory, 24
26 is a counter, and 25 is a comparator.

Claims (1)

[Scope of Claims] 1. Reception when an unreceivable signal is returned in response to a call signal sent from the terminal in a continuous terminal of a digital network having a switching function for making a call by specifying a signal transmission rate. an unreceivable detection means for detecting an unreceivable signal; a signal transmission speed changing means for changing the signal transmission speed to decrease when the detecting means detects an unreceivable signal; and a signal transmission speed changing means for changing the signal transmission speed by the signal transmission speed changing means. 1. A digital network terminal device comprising: calling means for making a call by specifying a signal transmission rate that has been set. 2 At a packet terminal in a digital network that has a switching function that makes a call by specifying the amount of information per unit time determined by the product of the amount of information contained in one packet and the number of packets sent out per unit time, unreceivable detection means for detecting a receivable unreceivable signal when a receivable unreceivable signal is returned in response to the transmitted calling signal; Information amount changing means for changing the amount of information to decrease, calling means for re-calling by specifying the amount of information changed by the information amount changing means, and the amount of information per specified unit time. 1. A digital network terminal device comprising: packet signal generating means for packetizing information including a calling signal so as to match the calling signal.