JPH0128549B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a packet add/drop device that selects packets from telephone and data terminals and transmits the packets from the terminals to a single subscriber line.

In a system whose purpose is to communicate with a packet switching network or a data terminal using a data terminal, when adding voice communication for the purpose, conventionally it was sufficient to install one new telephone line. However, voice communication does not require the same voice quality as normal daily conversation communication, but when it is required that the communication content be accurately transmitted to the other party, it is necessary to compress the voice band. Therefore, by converting it into a digital signal, economical packet communication that can transmit only the effective part of the communication becomes possible.

Therefore, if a telephone terminal is equipped with a circuit that converts voice information into a band-compressed digital signal and edits it into packets, it can be treated in the same way as a packet terminal, and when a telephone terminal is joined to a packet conversion network, is the same as when a packet terminal joins a packet conversion network.

However, when expanding the number of packet terminals, it is necessary to add one more line to the packet switching network, or to transfer packets from the packet terminals already accommodated between the packet switching network and the packet terminal being added. It is necessary to install a packet multiplexing device that has the function of multiplexing packets.

However, in the former case, the cost of installing new lines is enormous. In the latter case, equipment that performs packet multiplexing is introduced, but the data link between the packet switching network and the equipment requires not only frame-level processing according to high-level data link control (HDLC) procedures. Processing of the packet level interface in accordance with CCITT Recommendation X25 is required in the data link between existing packet terminals and newly installed packet terminals and the communication partner packet terminal connected to the packet switching network. Moreover, packet multiplexing equipment is designed to be economical by accommodating a large number of packet terminals, and even small-scale equipment achieves economical effects when accommodating 16 to 64 terminals. It is economically disadvantageous at the terminal level.

Therefore, in order to make it more economical than installing a telephone line, it is advantageous to add the above-mentioned circuit to the telephone and join the packet switching network, but for the reasons mentioned above, the conventional technology is not considered to be sufficiently economical. I couldn't say it.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above, to provide a voice packet drop/drop adder that can accommodate telephone terminals together with data terminals, is easy to expand, and is economical.

In order to achieve the above object, the present invention includes a voice packet creation circuit that detects voice from a telephone terminal, exchanges the voice into data, and converts it into packets, and a circuit that stores the packets on a first-come, first-served basis and outputs the packets on a first-come, first-served basis. a first-come, first-served storage circuit that stores packets from data terminals on a first-come, first-served basis and outputs them on a first-come, first-served basis; A voice communication system equipped with a packet selector circuit that selects packets alternately on a first-come, first-served basis to ensure that the packet data from the telephone terminal stored in the voice first-come, first-served storage circuit is transmitted to the line at least once during a certain period of time. A packet add/drop device is provided.

The details of this are as follows.

According to this configuration, even if the amount of accumulated packet data from a data terminal stored in the first-come, first-served storage circuit is greater than the amount of voice packet data stored in the first-come, first-served storage circuit from a telephone terminal, the first-come-first-served voice It becomes possible to reliably transmit the voice packet data accumulated in the sequential storage circuit to the line once in a certain period of time, and when the amount of accumulated packet data from the data terminal is large, the voice packet data is transmitted to the line for a long period of time. This can prevent situations in which transmission is not possible.

Additionally, in order to ensure that the audio data stored in the audio first-come, first-served storage circuit is sent to the line at least once during a certain period, we decided to alternately select audio and data, which can be achieved with a simple circuit configuration. can.

Embodiments of the present invention will be described below with reference to the drawings. Reference numeral 1 denotes an audio packet add/drop device; 2 stores packets from the audio packet creation circuit 16 on a first-come-first-served basis; a first-come-first-served storage circuit 5; and a first-come-first-served storage control circuit 6.
and an audio first-come-first-served storage section 3, which stores packets from the data terminal 15 on a first-come, first-served basis, and is comprised of a first-come-first-served storage circuit 8, a first-come-first-served storage control circuit 9, and an output gate circuit 10. The first-come-first-served storage unit 4 selects the packet output from the audio first-come-first-served storage unit 2 or the packet output from the first-come-first-served storage unit 3, transmits it to the subscriber line 13, and controls the output selection control circuit 11 and output selection. A packet selector unit includes a circuit 12; 5 is a first-come-first-served storage circuit that stores packets from the voice packet creation circuit 16 on a first-come-first-served basis; 6 detects reception of a packet from the voice packet creation circuit 16; a first-come, first-served accumulation control circuit that notifies information that can be selected by the accumulation control and output selection control circuit 11; 7 is an output gate circuit that controls the output from the first-come-first-served accumulation circuit 5 with a control signal from the output selection control circuit 11; 9 is a first-come-first-served storage circuit that stores packets from the data terminal 15 on a first-come, first-served basis, and 9 is a first-come-first-served storage circuit that detects the reception of a packet from the data terminal 15, controls the storage of the packet, and notifies information that can be selected by the output selection control circuit 11. Forward accumulation control circuit, 1
0 is an output gate circuit that controls the output from the first-come-first-served accumulation circuit 8 with a control signal from the output selection control circuit 11; 11 is the packet accumulation information from the first-come-first-served accumulation control circuit 6 and the packet from the first-come-first-served accumulation control circuit 9; An output selection control circuit 12 receives the accumulation information and transmits a control signal for the output from the first-come-first-served accumulation circuit 5 to the output gate circuit 7 and a control signal for the output from the first-come-first-served accumulation circuit 8 to the output gate circuit 10. An output selection circuit selects the packet output from the output gate circuit 7 and the packet output from the output gate circuit 10 and transmits the packet to the subscriber line 13; Selector section 4
14 is a telephone terminal accommodated in the voice packet add/drop multiplexer 1; 15 is a data terminal accommodated in the voice packet add/drop multiplexer 1;
is an audio packet creation circuit that receives audio from a telephone terminal and converts only voiced audio into packets.

In the above configuration, when the voice from the telephone terminal 14 is detected by the voice packet creation circuit 16 and converted into a packet, and received and detected by the first-come-first-served accumulation control circuit 6, the detection signal is sent to the first-come-first-served accumulation circuit. 5 and the output selection control circuit 11.
The storage circuit 5 stores packets obtained by converting the voice from the telephone terminal 14 in response to a signal from the control circuit 6. On the other hand, when a packet from the data terminal 15 is received and detected by the first-come-first-served storage control circuit 9, the detection signal is passed to the first-come-first-served storage circuit 8 and the output selection control circuit 11. 8 stores the packets from the data terminal 15 in response to the signal from 9.

Therefore, the control circuit 11 alternately selects the output request signals from the control circuits 6 and 9 accompanying the packet output signals from the storage circuits 5 and 8 on a first-come, first-served basis. At this time, if the output from the storage circuit 5 is to be selected, the packet output from the storage circuit 5 can be selected via the gate circuit 7 by sending a gate control signal and a packet selection signal to the gate circuit 7 and the selection circuit 12. It is transmitted by circuit 12 to line 13. On the other hand, if the output from the storage circuit 8 is selected, a gate control signal and a packet selection signal are sent to the gate circuit 10 and the selection circuit 12, so that the packet output from the storage circuit 8 is selected from the gate circuit 10.
The selection circuit 12 sends the signal to the line 13 via the selection circuit 12. Here, the storage circuits 5 and 8 are memory circuits capable of first-in-first-out (FiFO) input/output, and the output selection control circuit 11 is a small-scale processing circuit of a microcomputer and a large-scale integrated circuit for transmission control ( This is a logic circuit that can be realized by combining Lsi).

As mentioned above, when adding a telephone terminal to the current system, it can be accommodated in a packet conversion network by adding a circuit that converts voice to packets, but at that time, it is necessary to install a new packet line or use packet multiplexing to multiplex packets. It is necessary to introduce equipment,
The costs of introducing line equipment and packet multiplexing equipment cannot be ignored. According to the present invention, by selecting multiple packet accommodating lines, it is only necessary to prepare a simple logic for inserting and transmitting to a single line, and complex transmission control can be performed using more than a dozen LSIs thanks to the latest advances in semiconductor technology. It is possible to realize this with Therefore, if a device of the present invention is introduced when a new terminal is added, the cost can be reduced.

Furthermore, even if the amount of accumulated packet data from a data terminal stored in the first-come, first-served storage circuit is greater than the amount of voice packet data stored in the first-come, first-served audio storage circuit from a telephone terminal, the amount of packet data stored in the first-come, first-served audio storage circuit is It is now possible to reliably send the accumulated voice packet data to the line once during a certain period of time, and to prevent the situation where voice packet data cannot be sent to the line for a long period of time when the amount of accumulated packet data from the data terminal is large. It can be prevented.

[Brief explanation of drawings]

The figure shows an embodiment of a voice packet add/drop device according to the present invention. DESCRIPTION OF SYMBOLS 1...Audio packet add/drop device, 2...Audio first-come-first-served storage section, 3...First-come-first-served storage section, 4...Packet selector section, 5, 8...First-come-first-served storage circuit,
6, 9...First-come-first-served accumulation control circuit, 7, 10...Output gate circuit, 11...Output selection control circuit, 12
... Output selection circuit, 13 ... Subscriber line, 14 ...
Telephone terminal, 15...data terminal, 16...voice packet creation circuit.

Claims (1)

[Claims] 1. In a device that accommodates a telephone terminal, a data terminal, and a line that selects and transmits received packets from these telephones and data terminals and receives packets to be transmitted to the terminal, detects audio from the telephone terminal, A voice packet creation circuit that converts voice into data and packetizes it; a voice first-come-first-served storage circuit that stores and outputs the packets on a first-come, first-served basis; and a first-come, first-served voice storage circuit that detects reception of packets from data terminals and stores them on a first-come, first-served basis. , and by alternately selecting the output of received packets from the first-come-first-served storage circuit and the audio first-come-first-served storage circuit and the output of the received packets from the first-come-first-served storage circuit on a first-come, first-served basis, the audio first-come-first-served storage circuit 1. A voice packet drop/add device comprising a packet selector circuit that reliably transmits packet data from a telephone terminal stored in a telephone terminal to a line at least once during a certain period of time.