JP2004080782A - Digital closed area network provided with telephone switchboard and key telephone system, and signal transmission method in the digital closed area network - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital closed area network which is constructed from a telephone exchange and a key telephone system for transmitting voice, data, and video signals and maintains an excellent transmission quality of voice signals. <P>SOLUTION: The digital closed area network includes a telephone exchange (10) and a plurality of telephone sets (20) connected to network devices (30) such as a computer, a hub and a network printer. Data and video information is transmitted in a packet form by the closed area network. Further, transmitted audio signals are converted to a voice packet form by the telephone sets, whereby the excellent transmission quality is obtained. Further, the transmission priority among the voice, data and video packets is controlled in the closed area network, a great quantity of packets are transmitted and the voice packets are transmitted in high real time. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a digital closed network including a telephone exchange and a key telephone system (hereinafter, referred to as “KTS”) and a signal transmission method in the network, and more particularly to a digital transmission network having a function of transmitting signals for voice, data, and video. Related to digital closed networks that maintain communication quality.

Voice transmission technology (Voice over Internet Protocol) based on the Internet protocol (hereinafter referred to as "VoIP") has an advantage that communication costs are lower than conventional telephone systems, and data can be integrated. . For this reason, more and more companies are using VoIP as a communication means. Based on existing VoIP, businesses can simultaneously perform signal transmission for voice, data, and video (or images, video or images hereinafter) using a single IP platform. Therefore, not only is the process of network management simplified, but also the overall cost is reduced. Referring to FIG. 4, a local area network (hereinafter, referred to as "LAN") integrated with a telephone exchange system mainly includes a hub 70, a computer 71 connected to the hub 70, and a telephone connected to the hub 70. And an exchange 72. The hub 70 is further connected to a switching telephone 73. In the example shown in FIG. 5, the hub 70 is connected to a plurality of computers 71, and some specific computers 71 are connected to a telephone exchange 72 or a switching telephone 73.

In the network configuration described above (hereinafter referred to as “network architecture”), the switching telephone 73 uses only a part of the band (for example, 4 KHz) for transmitting the audio signal. However, in the related art, the transmission target, whether an IP network or a LAN, is mainly a data signal (specifically, for example, a data packet). The purpose of the design of the network architecture is still aimed at improving the reliability, for example during the transmission process, so that data packets have the highest transmission priority. In such a situation, when a large amount of data is transmitted between the plurality of computers 71, a serious problem of delay in transmission of the audio signal and occurrence of jitter (signal fluctuation) due to the delay occurs. However, for voice signals, the most important condition that is essential is quick transmission (eg real-time transmission). Thus, poor transmission quality is immediately apparent.

Since the conventional network structure cannot solve the problem of delay in signal transmission, there is a method using a wide bandwidth as a temporary method for improving the transmission quality of an audio signal and reducing the problem.

However, when a very large amount of data is transmitted, these data still cause a delay in the transmission of voice, so that the temporary method as described above cannot completely solve the problem.

In order to overcome the above drawbacks, an object of the present invention is to provide a digital closed network capable of preventing or reducing the drawbacks.

That is, an object of the present invention is to provide a digital closed network constructed by a telephone exchange and a key telephone system (KTS) for transmitting signals for voice, data and video and maintaining excellent transmission quality for voice signals. Is to do.

A signal transmission method in a closed network according to the present invention is a signal transmission method in a closed network including at least one telephone exchange (10) and a key telephone system having a plurality of telephones (20). Connecting to a telephone exchange; using each telephone as a node for connection to a network device (30) to form the closed network for the transmission of voice, data and video; Converting the voice packet into a voice packet format, and transmitting the voice packet to another one of the telephone sets that converts the voice packet into a voice signal format and converts the voice packet into voice. It is set to have the highest transmission priority by the setting of the telephone.

The network device can be, for example, a personal computer or a telephone exchange. Preferably, the telephone has a signal conversion function of converting the audio signal into the audio packet as well as processing the data and video packets.

The telephone further has a priority setting function for determining a transmission priority between the voice packet and another type of packet.

The digital closed network according to the present invention has a function of converting and restoring voice packets, and transmits voice, data and video to and from at least one telephone exchange (10) connected to a plurality of communication main lines or dedicated lines. A plurality of telephones (20) connected to the telephone exchange to form the closed network, and a plurality of network devices 30 respectively connected to the telephones to communicate with the telephone exchange. And

Each of the telephones (20) further includes a control device (21) having a bidirectional conversion function capable of converting a voice signal into a voice packet format and restoring the voice packet into the voice signal. A handset (22) capable of transmitting a signal to the control device and vocalizing an audio signal output from the control device; and a first handset connected between the control device and one of the network devices. A network connection interface (23), a second network connection interface (24) connected between the control device and the telephone exchange, wherein the telephone exchange comprises a plurality of the main communication lines; A packet processing device (11) disposed between the network interface and a connection interface (12) connected to the network connection interface. One network connection interface is connected to a network interface device connected to the network device, and each telephone further includes a first network connection interface and a second network connection interface for controlling a transmission flow. The control device is further connected to a display device (26), a button set (25), and an imaging device (27).

Preferably, the telephone exchange can be a private branch exchange (hereinafter, referred to as “PBX”). The network device can be a computer, a network printer, a hub, or the like.

According to the present invention, since the audio signal is transmitted in the audio packet format through the closed network, influences caused by a large number of data packets and video packets are eliminated, and transmission quality is improved.

When the voice packet is set to the highest priority, excellent reliability for data and video packets is maintained, and the real-time transmission requirement for the voice packet is achieved.

In the network configuration (network architecture) described above, the packets for the audio, data, and video can be transmitted between the network devices via the plurality of telephones. Furthermore, these packets can be transmitted to an external network via the PBX. Since the audio is transmitted in the audio packet format, the requirements are met for both real-time audio transmission and reliable data / video packet transmission.

Referring to FIG. 1, the closed area network according to the present invention includes at least one telephone exchange (specifically, for example, a private branch exchange, hereinafter referred to as “PBX”) 10, a plurality of telephones 20, and a network device 30. Key Telephone System (KTS).

The PBX 10 connected to a plurality of communication main lines or dedicated lines (for example, a line such as XDSL (digital subscriber line)) converts bidirectionally, for example, converts an external voice signal into a voice packet format or voice packet. Is provided with a packet processing device 11 for restoring an audio signal into an audio signal.

The plurality of telephones 20 have various connection forms (for example, shown in FIGS. 2A, 2B, and 2C) so as to form a closed network for transmitting signals for voice, data, and video. Can be connected to the PBX 10 having

Network devices 30 such as a personal computer (example shown), a network printer, a hub, and a facsimile device are connected to the telephone 20 for communication over a closed network.

Each telephone 20 includes a control device 21, a handset-like handset 22, a first network connection interface 23, a second network connection interface 24, a button set 25 having keys or buttons, and a display device 26. And an imaging device 27 such as a charge-coupled device (hereinafter referred to as “CCD”) camera.

The control device 21 has a bidirectional conversion function, can convert an audio signal into an audio packet format, and can restore an audio packet to an audio signal. The handset 22 can receive an audio signal from a user and transmit the signal to the control device 21, or can convert an audio signal output from the control device 21 into audio. The first network connection interface 23 is connected to the control device 21. The first network connection interface 23 is connected to a network interface device connected to the network device 30. The network interface device may be an internal connection type interface card installed in the network device 30, or may be an external connection type device connected to the network device 30. The second network connection interface 24 is connected to the control device 21 and the PBX 10. The button set 25 is used for dialing or setting parameters and is connected to an input terminal of the control device 21 for this purpose. The display device 26 is connected to an output terminal of the control device 21 for displaying a message or a video or an image. The imaging device 27 is used for capturing an image, and is connected to an input terminal of the control device 21 for this purpose. The captured image is processed by the controller 21 for transmission into a video or image packet format.

Each telephone 20 further has a bridge 28 connected between the first network connection interface 23 and the second network connection interface 24 in order to perform closed area network transmission flow control.

The PBX 10 further has a connection interface 12 connected not only to the packet processing device 11 but also to the second network connection interface 24 of each telephone 20.

From the above description of the network architecture, the plurality of telephones 20 not only allow the PBX 10 to establish a closed network in the enterprise, but also allow personal computers, hubs, network printers, etc. to communicate with the closed network ( It is also used as a relay node (hereinafter, referred to as a “node”).

Of particular note is that when audio signals are transmitted by the closed network according to the present invention, the network provides excellent transmission quality. For example, when one telephone set 20 is used as a transmitter (voice transmission source), the voice input to the handset 22 is converted into a voice packet format by the control device 21 and transmitted over a closed network. After another telephone 20 used as a voice receiver receives the voice packet and converts the voice packet into a voice signal by the control device 21, the voice signal is converted to voice by the handset 22. Since voice is transmitted in the form of voice packets, transmission delay and jitter problems are resolved. Further, the transmission quality is further improved by controlling the control device 21 and the bridge 28 so that transmission priorities for audio packets, data packets, and video packets are appropriately set. In other words, real-time voice transmission can be ensured because of the controllable transmission flow in the closed network according to the invention.

In conclusion, as mentioned above, according to the specific network architecture with the telephone system having the packet conversion function and the bridge function selectivity, it is possible to execute the rapid voice transmission avoiding the delay and the jitter problem. Can be. Further, the network architecture described above is compatible with data transmission protocols such as IEEE 802.3 to ensure that data / voice packets are correctly transmitted between all nodes of the network. In other words, according to the present invention, high reliability for data / video transmission can be maintained.

FIG. 2 is a functional block diagram of the structure of a digital closed network according to the present invention. (A), (b), (c) is a schematic diagram of a connection form showing a network private branch exchange (net @ work-PBX) connected to a plurality of telephones in the digital closed network according to the present invention. 1 is a schematic diagram showing a preferred embodiment of a closed network according to the present invention. FIG. 2 is a functional block diagram of a conventional network structure. Functional block diagram of another conventional network structure

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 10 Telephone exchange 11 Packet processing device 20 Telephone 21 Control device 22 Handset 23, 24 Network connection interface 25 Button set 26 Display device 27 Imaging device 28 Bridge 30 Network device

Claims (3)

A method for transmitting signals in a closed network comprising at least one telephone exchange (10) and a key telephone system having a plurality of telephones (20),
Connecting each telephone to the telephone exchange;
Using each telephone as a node for connection to a network device (30) so as to form said closed network for the transmission of voice, data and video;
Converting voice received from one of the telephones into a voice packet format, and transmitting the voice packet to another one of the telephones that converts the voice packet into a voice signal format and converts it to voice. ,
The signal transmission method in a closed network, wherein the voice packet is set to have the highest transmission priority by setting of the telephone. A digital closed network,
At least one telephone exchange (10) having a function of converting and restoring voice packets and connected to a plurality of communication main lines or dedicated lines;
A plurality of telephones (20) connected to the telephone exchange to form the closed network capable of transmitting voice, data and video;
A digital closed network comprising: a plurality of network devices 30 each connected to the telephone so as to be able to communicate with the telephone exchange. Each telephone (20) further comprises
A control device (21) having a bidirectional conversion function capable of converting a voice signal into a voice packet format and restoring the voice packet into the voice signal;
A handset (22) capable of transmitting the received audio signal to the control device and converting the audio signal output from the control device into a voice,
A first network connection interface (23) connected between the control device and one of the network devices;
A second network connection interface (24) connected between the control device and the telephone exchange;
The telephone exchange includes a packet processing device (11) disposed between the plurality of communication main lines and a connection interface (12) connected to the second network connection interface.
The first network connection interface is connected to a network interface device connected to the network device,
Each telephone further includes a bridge (28) connected between the first network connection interface and the second network connection interface to control a transmission flow;
The digital closed network according to claim 2, wherein the control device is further connected to a display device (26), a button set (25), and an imaging device (27).

Images