JP3215767B2 - Network system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network system in which a network is constructed by a plurality of nodes, and each node compresses voice signals and communicates with each other.

[0002]

2. Description of the Related Art In a voice coded communication system, a network is constructed by connecting an exchange to each of a plurality of terminal devices, connecting a relay device (node) to each exchange, and connecting between the nodes. I have. Then, voice communication was performed between the terminal devices through each node. In this case, in order to reduce the amount of audio information, each node employs an audio encoding method for compressing an audio signal.

On the other hand, there is a case where it is desired to add a new node to the network constructed in this way. In this case, as the technology advances, there is a case where a new node may want to adopt a voice coding scheme having better performance than the voice coding scheme.

However, there is no correspondence between the existing speech coding method and the new speech coding method. For this reason, switching to a new speech coding system including the existing network has been performed. Alternatively, an existing speech coding method has been adopted for a new node.

In order to improve the voice quality between specific nodes among a plurality of nodes, it is conceivable to change the voice coding scheme between the specific nodes to a voice coding scheme having good performance.

[0006]

However, even when the speech coding system between the specific nodes is changed to a speech coding system having a high performance, it is not possible to cope with a specific node and another node. For this reason, the speech coding method of all nodes including the other nodes has been switched to a speech coding method with good performance.

[0007] It is an object of the present invention to provide a network system which employs an appropriate one of two types of speech coding systems in communication between nodes when constructing a network.

[0008]

The present invention adopts the following means in order to solve the above-mentioned problems. <Summary of Network System of the Present Invention> As shown in the principle diagram of FIG. 1, the network system of the present invention includes a plurality of exchanges 20 connected to one terminal device 10 and a plurality of exchanges 20 connected to the other terminal device 10. A network is constructed by connecting via these nodes, and voice communication is performed between terminal devices through each node. The network system of the present invention includes one or more first nodes 40, two or more second nodes 30, and control means 33.

[0009] The one or more first nodes 40 have a first speech coder 35 for compressing speech signals according to a first speech coding scheme. The two or more second nodes 30 are a first speech coding device 35 for compressing a speech signal according to the first speech coding method, and a second speech code different from the first speech coding method. And a second audio encoding device 34 for compressing an audio signal by an encoding method. The control means 33
The second speech encoder 34 is selected when communication is performed between the second nodes 30, and the first speech codec is selected when communication is performed between the first node 40 and the second node 30. The chemical device 35 is selected.

The point is to efficiently construct a network when there are a plurality of nodes employing different types of speech coding systems. Here, the terminal device is a telephone or the like. [First Component] The first speech encoding device 35
And a codec comprising a coder and a decoder.
As the first audio coding method, for example, ADPCM (Ad
aptive Differential Pulse Code Modulation).

[Second Constituent Element] The second audio encoding device 34 compresses an audio signal by a second audio encoding method different from the first audio encoding method.
For example, it is a codec including a coder and a decoder. As the second audio coding method, for example, ADM (Ad
aptive Delta Modulation, CELP
There are coding methods and the like.

[Third component] The control means 33
When performing communication between the nodes 30, the second speech encoder 34 is selected, and the first node 40 and the second node 3 are selected.
The first speech coding device 35 is selected when performing communication with 0, for example, a central processing unit (CPU). In addition, the control unit 33 may perform processing by the CPU executing a program stored in the memory.

<Summary of Node of the Present Invention> A node for a network that performs communication between nodes includes a first speech encoding device 35, a second speech encoding device 34, and a control means 33. The first audio encoding device 35 compresses an audio signal using a first audio encoding method. The second audio encoding device 34 compresses the audio signal using a second audio encoding method of a type different from the first audio encoding method. Control means 3
Reference numeral 3 switches between the first speech coding apparatus 34 and the second speech coding apparatus 35 according to the speech coding scheme of the partner node.

<Summary of the Switch of the Present Invention> A first speech encoding device 35 for compressing speech signals by a first speech encoding method and a second speech code different from the first speech encoding method And a second audio encoding device 34 for compressing the audio signal in accordance with the encoding scheme. When performing communication between the one node and the other node, the exchange switches the first voice coding device 34 and the second voice coding device 34 in the one node in accordance with the voice coding method of the other node.
And control means 33 for switching with the audio encoding device 35.

<Additional Configuration Requirements in the Present Invention> The present invention is composed of the essential components described above, but can also be established by adding the following configuration.

Control means 3 in the network system
3 may include a number analysis unit 32 and a connection switching unit 33a. The number analysis unit 32 analyzes a node number for selecting each node transferred from the terminal device 10 and determines whether the node number belongs to the first node or the second node. .

The connection switching unit 33a performs a switching connection to select one of the first and second speech encoding devices 35 and 34 according to the determined node. Here, the connection switching unit 33a can be, for example, a switch, a multiplexer, or the like.

The control means 33 in the node may include a number analyzing section 32 and a connection switching section 33a. Further, the control means 33 in the exchange may include a number analyzing section 32 and a connection switching section 33a.

[0019]

[Action]

<Operation of the Network System of the Present Invention> A first node is provided with a first speech encoder 35 and a second speech encoder 34, and control is performed when communication is performed between the second nodes 30. Means 33 selects a second speech encoding device. Accordingly, the audio signal is compressed by the second audio encoding device 34, and audio communication is performed between the terminal devices.

On the other hand, the first node 40 and the second node 3
When performing communication with 0, the control unit 33 selects the first speech encoding device 35. Therefore, the audio signal is compressed by the first audio encoding device 35, and audio communication is performed between the terminal devices.

That is, in the communication between nodes, an appropriate one of the two types of voice coding systems is adopted, so that voice communication can be easily performed between the terminal devices.

<Operation of Node of the Present Invention> When communication is performed between nodes, the control means 33 provided in the node uses the first speech coding apparatus 3 according to the speech coding system of the partner node.
4 and the second speech encoding device 35,
The first audio coding method and the second audio coding method can be selectively adopted.

<Operation of Switch of the Present Invention> When communication is performed between one node and the other node, the control means 33 provided in the switch exchanges data according to the voice coding system of the other node. Since the switching between the first speech encoding device 34 and the second speech encoding device 35 in the one node is performed, the first speech encoding method and the second speech encoding method can be selectively selected. Can be adopted. In this case, since the exchange gives a switching instruction to one node, it is necessary to manage the number of one node.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the network system according to the present invention will be described below with reference to the drawings. FIG. 2 shows Embodiment 1 of the present invention.
It is a block diagram of a structure of. <Embodiment 1> The network system is the telephones 10a-1
0c, private branch exchange (hereinafter, referred to as PBX) 20a,
20b, and the relay exchanges 12 and 13. It is also assumed that an old node 40 is already provided in the network system, and new nodes 30a and 30b are newly added to such a network system.

The telephone 10a is a PBX 2 for performing an exchange process.
0a, and exchanges signaling information with the PBX 20a. The telephone 10b is connected to the PBX 20b, and exchanges signaling information with the PBX 20b.

The signaling information is the telephone number of the other party, and the telephone number includes the node number to be relayed. The PBX 20a is connected to a new node 30a as a relay device newly added to the network,
X20b is connected to the new node 30b. New node 3
The old node 40 already provided in the network is connected to 0a and the new node 30b.

The telephone 10c is connected to the old node 40 through the transit exchange 12 and the transit exchange 13. In the network thus constructed, voice communication can be performed between the telephones 10a to 10c via the new node and the old node.

FIG. 3 is a diagram for explaining communication between new nodes according to the first embodiment. In FIG. 3, the new node 30a is a PB
X interface (hereinafter, referred to as I / F) 31
a, number analysis unit 32a, connection switching units 33a-1, 33-
2. New codec 34a, old codec 35a, network port (NP) 36 connected to trunk line 15a
a.

The PBX I / F 31a controls input and output to and from the PBX 20a, and the PBX IF 31a is connected to a connection switching unit 33a-1 and a number analysis unit 32a. The number analysis unit 32a includes connection switching units 33a-1, 33a-2.
Is connected. Connection switching unit 33a-1 and connection switching unit 33
a-2 is the new codec 34a and the old codec 35
a are respectively connected.

The number analysis unit 32a analyzes a node number for selecting each node transferred from the telephone 10a and communicates with the old node 40 or the telephone 10b for communication with the telephone 10c. It is determined whether or not it is a new card 30b for executing The number analysis unit 32a performs processing by, for example, executing a program stored in a memory by a CPU.

The connection switching units 33a-1 and 33a-2 select the first speech coder 35 if the determined node is the old node, and if the determined node is the new node. Selects the second speech encoder 34. The connection switching units 33a-1 and 33a-2 are configured by, for example, switches.

The new node 30b includes a PBXI / F 31b,
Number analysis unit 32b, connection switching units 33b-1, 33b-
2, a new codec 34b, an old codec 35b, and a network port 36b connected to the trunk line 15b. Each part of the new node 30b
Since the configuration is the same as that of each section b, the details of each section are omitted here.

The old node 40 comprises one old codec 35c, an NP 36c connected to the trunk line 15a, and an NP 36d connected to the trunk line 15b. The old codecs 35a to 35c and the new codecs 34a to 34b include a coder that compresses an audio signal (for example, 64 Kb / s) into an audio signal of, for example, 32 Kb / s or 16 Kb / s, And a decoder for restoring the data.

The old codecs 35a to 35c use an ADPCM (Adaptive Differential Pu
lse Code Modulation (adaptive differential pulse modulation).
The ADPCM method samples an audio signal and sequentially changes the quantization width according to the difference between samples.

The new codecs 34a to 34b use ADM (Adaptive Delta Modulation), CELP coding or the like as a voice coding system. A
In the DM system, sampling is performed at a high frequency, and a differential signal is transmitted in one bit. The CELP method is a method in which a sampled audio signal is vector-quantized and transmitted in combination with linear prediction.

FIG. 4 shows the constituent blocks of the codec.
Each codec includes low-pass filters 301a and 301b, an analog / digital converter (A / D) 302, a digital / analog converter (D / A) 303, a digital signal operation unit 304, and an interface 305.

The low-pass filters 301a and 301b allow only low-frequency component audio signals of the input audio signals to pass. An A / D 302 is a coder that converts an analog signal into a digital signal, and a D / A 303 is a decoder that converts a digital signal into an analog signal. The digital signal operation unit 304 includes a multiplier, an adder / subtractor, and a memory, and performs an operation process on the digital signal according to an encoding algorithm.

Next, the operation of the first embodiment configured as described above will be described. FIG. 5 is a flowchart illustrating the processing of the first embodiment. The processing of the first embodiment will be described with reference to the drawings. <Communication Between New Nodes> First, communication between new nodes, that is, a communication method between new codecs will be described with reference to FIG.

First, the signaling information transferred from the telephone 10a is sent to the number analyzer 32a through the PBX 20a and the PBX IF 31a (step 10).
1). The signaling information includes, for example, a node number XXX to be selected and an extension number YYYY at the selected node.

The number analysis unit 32a analyzes the node number XXX included in the signaling information to determine whether the node number is the new node 30b or the old node 40 (step 102).

Here, the number analysis unit 32a is the new node 30
If the number is determined to be b, the number analysis unit 32a instructs the connection switching units 33a-1 and 33a-2 to establish an internal path via the new codec 34a (step 103).

The connection switching units 33a-1 and 33a-2 select the new codec 34a. Then, the signaling information is sent from the new node 30a to the old node 40 (step 104).

The old codecs 35c, 3 in the old node 40
In 5d, the pass-through mode is set. For this reason,
The signaling information sent to the old node 40 is sent to the number analysis unit 32b in the new node 30b through the transit exchange 12 (step 105).

The number analysis unit 32b analyzes the node number included in the signaling information to obtain the new node 30a.
It is determined whether the call is from the old node 40 or from the old node 40 (step 106).

Here, the number analysis unit 32b transmits the new node 30
If it is determined that the call is from a, the number analysis unit 32b instructs the connection switching units 33b-1 and 33b-2 to establish an internal path via the new codec 34b (step 107). Connection switching units 33b-1, 33b-
2 selects the new codec 34b.

Then, the signaling information is transmitted to the new node 30.
b to the telephone 10b via the PBX 20b (step 108). In this way, the new node 30a,
At 30b, communication with the new codecs 34a, 34b is established.

That is, in the communication between the new nodes, the appropriate new node speech coding scheme of the two types of speech coding schemes is employed, so that voice communication can be easily performed between the terminal devices.

The above description is from the telephone 10a to the telephone 10
The voice communication to b has been described. For example, when performing voice communication from the telephone set 10b to the telephone set 10a, an appropriate new node voice coding scheme of the two types of voice coding schemes is adopted in communication between the new nodes. <Communication between New Node and Old Node> Next, communication between the new node and the old node, that is, a communication method between the old codecs will be described. FIG. 6 is a diagram illustrating communication between the new node and the old node according to the first embodiment.

First, signaling information from the telephone set 10a is sent to the number analysis unit 32a through the PBX 20a and the PBX I / F 31a (step 101). The number analysis unit 32a analyzes the node number included in the signaling information to determine whether the node is a new node or an old node (step 102).

Here, the number analysis unit 32a is the old node 40
If it is determined that the connection switching unit 3
Instruct 3a-1 and 33a-2 to establish an internal path via the old codec 35a (step 1).
09).

The connection switching units 33a-1 and 33a-2 select the old codec 35a. Then, the signaling information is sent from the new node 30a to the old node 40 (Step 110). Old codec 35c in old node 40
Sends or codes the signaling information to the telephone set 10b via the transit exchanges 12 and 13 (step 111).

In this way, communication between the old codecs 35a and 35c is established between the new node 30a and the old node 40. In other words, the communication between the new node and the old node uses the voice coding method of the old node among the two types of voice coding methods, so that voice communication can be easily performed between the terminal devices.

The above description is from the telephone 10a to the telephone 10
Voice communication to c has been described. For example, also when performing voice communication from the telephone 10c to the telephone 10a, the voice coding method of the old node is adopted. <Embodiment 2> Next, Embodiment 2 of the present invention will be described. In the second embodiment, the PBX 21a includes the number analysis unit 32a. The PBX 21b includes the number analysis unit 32b. In this case, the number analysis unit 32a is deleted from the new node 30a. The number analysis unit 32b is used for the new node 3
0b.

The other configuration is the same as the configuration of the first embodiment, and the same portions will be described with the same reference numerals. FIG. 7 is a diagram for explaining communication between new nodes according to the second embodiment of the present invention. <Communication between New Nodes> First, the signaling information transferred from the telephone 10a is sent to the number analysis unit 32a in the PBX 21a. Then, the number analysis unit 32a analyzes the node number XXX included in the signaling information to determine whether the node number is the new node 30b or the old node 40.

Here, the number analysis unit 32a is connected to the new node 30.
b, the number analysis unit 32a outputs the PBXI
/ F31a and connection switching units 33a-1, 33a-2
To establish an internal path via the new codec 34a. Subsequent processing is the same as the processing of the first embodiment.

That is, in the communication between the new nodes, an appropriate new node speech coding scheme of the two types of speech coding schemes is adopted, so that voice communication can be easily performed between the terminal devices. <Communication Between New Node and Old Node> FIG. 8 is a diagram for explaining communication between the new node and the old node according to the second embodiment. First, the signaling information from the telephone 10a is a PBX 21
The number is sent to the number analysis unit 32a in a. This number analysis unit 3
2a determines whether the node is a new node or an old node by analyzing the node number included in the signaling information.

Here, the number analysis unit 32a is the old node 40
If the number analysis unit 32a determines that the PBXI / F
It instructs the connection switching units 33a-1 and 33a-2 to establish an internal path via the old codec 35a through 31a. Subsequent processing is the same as the processing of the first embodiment.

In other words, the communication between the new node and the old node uses the voice coding method of the old node among the two types of voice coding methods, so that voice communication can be easily performed between the terminal devices. .

As described above, the number analysis unit 32a is connected to the PBX 21
a and the number analysis unit 32b is provided in the PBX 21b, the same effect as in the first embodiment can be obtained. In this case, for example, the PBX 21a needs to manage the number of the new node in order to give a switching instruction to the new node.

In the first and second embodiments, a plurality of nodes are composed of a new node and an old node. For example, a new codec and an old codec may be provided in a specific node among a plurality of nodes. The present invention can be applied to such a case.

[0061]

According to the network system of the present invention, when the control means communicates between the second nodes, the control means selects the second speech coding apparatus, and the first node and the second node are connected to each other. The first speech encoding device is selected when the communication is performed.

Accordingly, in the communication between the nodes, one of the two types of voice coding schemes is adopted, so that voice communication is performed between the terminal devices. Further, according to the node of the present invention, the control means provided in the node switches between the first speech coding apparatus and the second speech coding apparatus according to the speech coding scheme of the partner node. , The first speech coding scheme and the second speech coding scheme can be selectively adopted.

Further, the control means provided in the exchange comprises:
Since the switching between the first speech encoding device and the second speech encoding device in one node is performed according to the speech encoding system of the other node, the first speech encoding system and the second speech encoding device are switched. An encoding method can be selectively adopted. In this case, since the exchange gives a switching instruction to one node, it is necessary to manage the number of one node.

[Brief description of the drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration block diagram of a first embodiment of the present invention.

FIG. 3 is a diagram illustrating communication between new nodes according to the first embodiment.

FIG. 4 is a configuration block diagram of a codec.

FIG. 5 is a flowchart illustrating a process according to the first embodiment.

FIG. 6 is a diagram illustrating communication between a new node and an old node according to the first embodiment.

FIG. 7 is a diagram illustrating communication between new nodes according to the second embodiment of the present invention.

FIG. 8 is a diagram illustrating communication between a new node and an old node according to the second embodiment.

[Explanation of symbols]

 Telephones 12, 13 Relay exchanges 20a, 20b PBX 30a, 30b New nodes 31a, 31b PBXI / F 32a, 32b Number control units 33a-1 to 33b-2 -Connection switching units 34a, 34b-New codecs 35a-35d-Old codecs 36a-36d-Network ports 40-Old nodes

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04M 3/00 H04B 1/62-1/68 H04M 7/00

Claims (3)

(57) [Claims] A network is constructed by connecting an exchange (20) connected to one terminal device (10) and an exchange (20) connected to the other terminal device (10) via a plurality of nodes. In a network system for performing voice communication between terminal devices through each node, at least one first node (40) having a first voice coding device (35) for compressing a voice signal by a first voice coding method ), A first audio encoding device (35) for compressing an audio signal according to a first audio encoding method, and an audio signal according to a second audio encoding method different from the first audio encoding method. Two or more second nodes (30) having a second speech encoding device (34) for compressing the second speech encoding device, and a second speech encoding when communication is performed between the second nodes (30). Select device (34) First node (40)
When communication is performed between the first node and the second node (30), the first
Control means (33) for selecting the audio coding device (35)
A network system comprising: 2. A first speech coding device (35) for compressing a speech signal according to a first speech coding method in a network node that performs communication between nodes; and a first speech coding method. A second speech coding apparatus (34) for compressing a speech signal by a second speech coding scheme of a type different from that of the first speech coding apparatus (34) according to a speech coding scheme of a partner node; 34. A node comprising: a control unit (33) for switching between the second speech encoding device (35) and the second speech encoding device (35). 3. A first speech coding apparatus (35) for compressing a speech signal by a first speech coding scheme, and a speech by a second speech coding scheme different from the first speech coding scheme. When a second speech encoding device (34) for compressing a signal is provided at one node and communication is performed between this one node and the other node, the speech encoding method of the other node is used. Control means (33) for switching between the first speech coder (34) and the second speech coder (35) in said one node in response
An exchange characterized by comprising: