JPH11298497A - Atm access system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a communication time of data communication with lower communication priority. SOLUTION: Personal computer terminals 1-3 and telephone terminals 4-6 connect to an asynchronous transfer mode ATM access device 100 and they make data communication and voice communication via an ATM network. A communication monitor means 120 monitors a silence state of voice communication with high priority traffic among communication traffic where a terminal connecting to a down link connection means 110 makes transfer to the ATM network and informs a connection control means 160 of silence information. When the connection control means 160 managing a band resource of the ATM network being an up link channel receives silence information from the communication monitor means 120, the means 160 controls the high priority traffic band resource by using a resource management RM cell so that the high priority traffic band resource producing the silent information is used for data communication of low priority traffic while the silent information is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a connection control method for an ATM (Asynchronous Transfer Mode) access device to which high-priority traffic and low-priority traffic are connected.

[0002]

2. Description of the Related Art Conventionally, this kind of ATM access device has
To accommodate a telephone terminal that handles voice communication, a PC (personal computer) terminal that handles data communication, or a CT (computer telephony) terminal that handles voice, data, and image communication, and to connect to an ATM network as a multimedia backbone network Is used as a conversion device.

[0003] These access devices have different QOS
In order to handle multimedia traffic having (quality of service), call admission control and VC (virtual connection) flow control according to each service are required.

FIG. 16 is a block diagram showing an example of a conventional ATM access device. In FIG. 16, PC
The terminals 1 to 3 are connected to the ATM access device 400 and perform data communication via the ATM network. Also,
The telephone terminals 4 to 6 are connected to the ATM access device 400 and perform voice communication via the ATM network.

[0005] The downlink connection means 110 is, for example, I
It has an SDN interface and an Ethernet interface, accommodates the PC terminal and the telephone terminal, and extracts data communication packets and voice communication packets from respective communication traffic.

The cell assembling / disassembling means 130 is, for example, LS
It is composed of I-devices and converts the data communication packets or voice communication packets of each communication traffic into ATM cells of different VCs. It also assembles / disassembles the ATM cell of the VC signaling signal with the ATM network and the flow control signal of the connected VC.

[0007] The cell storage means 140 is composed of, for example, a FIFO device.
Are stored in buffers for different priorities according to the instruction of the connection control means 460.

[0008] The connection control means 460
The PU is a PU that performs a call admission control for adjusting a quality request and a signaling process for setting a VC between the PC terminal or the telephone terminal and the ATM network prior to the ATM communication.

FIG. 17 shows a conventional connection control means 4.
FIG. 3 is a block diagram showing an example of the configuration of the first embodiment; The resource management unit 461 in the connection control unit 460 manages the bandwidth resources of the ATM network, and transmits V to the ATM network, which is an uplink line, according to the call reception control information of the voice communication from the signaling processing unit 162.
Secure the C band resource. In addition, when the ATM network is congested, the flow control of the communicating VC is performed using the RM cell (resource management cell).

[0010] The signaling processing unit 162 in the connection control means 460 provides an ATM connection between the PC terminal or the telephone terminal via the downlink connection means 110 and the ATM network via the cell assembling / disassembling means 130.
Call admission control and V to adjust quality requirements prior to communication
A signaling process for setting C is performed. Also, according to the instruction of the resource management unit 161, the cell storage unit 14
0 is notified of the cell transfer rate of each buffer.

The uplink connection means 150 includes, for example,
It connects to a public ATM network with a 512 kbps bandwidth contract and transfers ATM cells.

Next, an example of the operation of the conventional ATM access device will be described with reference to the flowchart of FIG. Upon receiving a connection request from the terminal via the downlink connection means 110 (step 601), the connection control means 460 determines whether the request is data communication by a PC terminal or voice communication by a telephone terminal (step 601). Step 602).

In the case of data communication (data in step 602), the service category is UBR (unspecified bit rate) and the VC
The call processing for connection is performed, and instructions are given to the cell assembling / disassembling means 130 and the cell storage means 140 (step 604).

In the case of voice communication (voice in step 602), it is determined whether a band resource can be secured as an ABR (available bit rate) service category. (Step 605). If the resources can be secured (Y in step 605), after securing the band necessary for the voice communication, the cell assembling / disassembling means 130 and the cell storing means 140 are instructed to make a VC connection of the ATM network (step 605). 604). If the resource cannot be secured (N in step 605), it notifies the downlink connection means 110 to reject the connection request for the voice communication.

As described above, high-priority voice communication starts communication after securing bandwidth resources, whereas low-priority traffic data communication uses an available bandwidth.

[0016]

However, even in the case of high-priority traffic, effective traffic does not always flow using all the reserved bandwidth resources at the time of VC connection. For example, in the case of voice communication such as telephone, silence often occurs between conversations,
The communication may be put on hold by the operation of the communicator. The invalid voice communication transferred at these times is considered to have a lower communication priority than data communication such as file transfer, which waits for a free bandwidth resource as low-priority traffic.

That is, in voice communication, bandwidth resources are secured by call admission control before ATM communication, whereas in data communications, free bandwidth of the ATM network is used without securing bandwidth resources. If multiple voice communications occur simultaneously,
There is a problem that the time required for data communication, which is low-priority communication traffic, increases.

In the conventional VC flow control, control is performed only in accordance with the congestion state of the ATM network. A silent state of voice communication is detected, and in the silent state, a bandwidth resource secured by voice communication is temporarily used. Since the VC flow control is not performed, such as releasing the call, the voiced state and the silence state occur alternately in the voice communication. Since the same band as the sound state is occupied, there is a problem that the utilization efficiency of the transmission path is low.

In this silence state, it is conceivable to perform VC signaling processing such as temporarily releasing band resources and disconnecting and reconnecting VCs of high-priority traffic. In the case of an event that occurs frequently in time, VC signaling processing is enormously generated, so that the load on the CPU may increase and normal voice communication may not be performed.

As another means, it is conceivable to increase the bandwidth of the ATM network in order to increase the bandwidth resource. However, in the case of a public network, there is a problem that if the contract bandwidth is increased, the line cost increases accordingly.

It is an object of the present invention to solve the above-mentioned problem.
A TM access device is provided.

[0022]

SUMMARY OF THE INVENTION An ATM (Asynchronous Transfer Mode) access device according to the present invention monitors high-priority traffic and uses it in ATM communication of the traffic when valid information is not transferred to the high-priority traffic. V
By temporarily allocating the bandwidth resource secured by C (virtual connection) to the bandwidth of low priority traffic,
ATM communication of low-priority traffic is performed in a short time.

Specifically, among a plurality of ATM communications performed by a terminal connected to the downlink connection means via the ATM network, a communication monitoring means for monitoring a communication state of high-priority traffic is used for invalid information communication of the traffic. When the state is detected, information to that effect is sent to the connection control means. Upon receiving the information, the connection control means
Using the M cell (resource management cell), the bandwidth resource reserved by the high-priority traffic in the ATM communication is temporarily released and allocated to the bandwidth of the low-priority traffic. As a result, the ATM communication bandwidth of low-priority traffic increases, so that the communication time of low-priority traffic can be shortened.

[0024]

FIG. 1 is a block diagram showing a first embodiment of an ATM access device according to the present invention.
In FIG. 1, PC terminals 1 to 3 are connected to an ATM access device 100 and perform data communication via an ATM network. The telephone terminals 4 to 6 are connected to the ATM access device 100 and perform voice communication via the ATM network.

The downlink connection means 110 accommodates the plurality of PC terminals and telephone terminals, and extracts data communication packets and voice communication packets from the respective communication traffic.

The communication monitoring means 120 monitors the valid / invalid state of communication traffic, which is high-priority traffic, of the communication traffic transferred from the terminal connected to the downlink connecting means 110 to the ATM network, and checks the valid / invalid information. To the connection control means 160.

The cell assembling / disassembling means 130 converts data communication packets or voice communication packets of each communication traffic into ATM cells of different VCs. It also assembles / disassembles the ATM cell of the VC signaling signal with the ATM network and the flow control signal of the connected VC.

The cell storage means 140 stores the ATM cells from the cell assembling / disassembling means 130 into the connection control means 16.
According to the instruction of 0, the data is accumulated in the internal buffer for each different priority.

The connection control means 160 operates between the PC terminal or telephone terminal and the ATM network.
Call admission control and V to adjust quality requirements prior to communication
A signaling process for setting C is performed. It also manages bandwidth resources of the ATM network, which is an uplink line, and performs flow control of a VC during communication using RM cells according to congestion of the ATM network or valid / invalid information from the communication monitoring unit 120.

Uplink connection means 150 connects to the ATM network and transfers ATM cells. For example, 5
Connect to a public ATM network with a 12 kbps bandwidth contract.

Next, details of each block will be described. In this embodiment, among a plurality of service categories in the ATM communication, the voice communication from the telephone terminal is performed by ABR, and the data communication from the PC terminal is performed by UBR. In this case, voice communication is high-priority traffic and data communication is low-priority traffic.

FIG. 2 is a block diagram showing an example of the downlink connection means 110 according to the first embodiment of the present invention. The downlink connection means 110 includes an Ethernet interface 111 for connecting to a PC terminal and an ISDN interface 112 for connecting to a telephone terminal. Each communication traffic is performed by an IP (Internet Protocol) data extraction unit 113 or PCM (pulse code modulation) data. The extraction unit 114 assembles the data communication packet and the voice communication packet. These functions can be realized by, for example, a communication LSI and a memory.

FIG. 3 is a block diagram showing an example of the communication monitoring means 120 according to the first embodiment of the present invention. The communication monitoring unit 120 performs digital-to-analog conversion of the voice communication packet, which is high-priority traffic, by the voice decoder 121, and notifies the connection control unit 160 when the voice / silence determination unit 122 detects a voice / silence state. The sound / silence state detection function is, for example, a voice CODE.
This can be realized by the C device.

FIG. 4 is a block diagram showing an example of the cell storage means 140 according to the first embodiment of the present invention. In FIG. 4, the cell distribution unit 141 transfers the ATM cell generated by the cell assembling / disassembling unit 130 to one of the signaling cell buffer 142, the ABR cell buffer 143, and the UBR cell buffer 144 according to the instruction of the connection control unit 160. Transfer to

The signaling cell buffer 142 has a VC
This is a small-capacity buffer for storing ATM cells for performing signaling processing. The ABR cell buffer 143 is a medium-capacity buffer for storing voice communication ATM cells and ATM cells for flow control of the VC with which the ATM communicates.
The UBR cell buffer 144 is a large-capacity buffer that stores ATM cells for data communication and ATM cells for flow control of a VC communicating with the ATM.

The buffer management unit 145 transfers the ATM cells stored in the three buffers to the uplink connection unit 150 based on the cell transfer rate specified by the connection control unit 160. These features
For example, it can be realized by a memory and a control circuit.

FIG. 5 is a block diagram showing an example of the connection control means 160 according to the first embodiment of the present invention. In FIG. 5, the resource management unit 161
It manages the bandwidth resources of the ATM network, and secures the VC bandwidth resources of the ABR in the ATM network which is the uplink line according to the call admission control information of the voice communication from the signaling processing unit 162.

Further, when the ATM network is congested or voice communication is in a silent state, the flow control of the communicating VC is performed using the RM cell (resource management cell). For example, in accordance with the sound / non-sound information from the communication monitoring unit 120, the bandwidth control unit controls the bandwidth resources secured by the VC of the corresponding voice communication.

Signaling processing section 162 adjusts quality requirements between a PC terminal or telephone terminal via downlink connection means 110 and an ATM network via cell assembling / disassembling means 130 prior to ATM communication. It performs call acceptance control and signaling processing for setting a VC. Further, according to the instruction of the resource management unit 161, the cell storage unit 140 is notified of the cell transfer rate of each buffer. These functions are provided, for example, by a central processing unit (CP
U).

FIG. 11 is an explanatory diagram showing an example of an RM cell format used in VC flow control according to the present invention. This format is based on Traffic Management 4.0 (af-
tm-0056.000 Apr, 1996), but a new AI (Active Indication)
A value is defined, and based on this value, the sound / non-speech state of the voice communication of the transmitting terminal is notified to the opposite ATM access device in which the communication partner terminal is accommodated.

For example, if AI = 1, there is a sound, AI
If = 0, a silent state is defined. In addition, E is defined to indicate the cell transfer rate when the network is congested.
An R (Explict Rate) value is defined to indicate a cell transfer rate in a silent state. By transferring the RM cell of this format to the ATM network, the opposite device recognizes that the change is the band resource due to the change of the voiced / unvoiced state of the voice communication.

For signaling processing with the ATM network, for example, UNI Signaling 4.0 (af-sig-0061.000 J), which is a specification by the same ATM forum, is used.
uly, 1996), the service category and traffic management are, for example,
c According to Management 4.0 (af-tm-0056.000 Apr, 1996).

Next, an example of operations at the start and end of communication according to the first embodiment of the present invention will be described with reference to FIGS.

When the connection control means 160 receives a connection request from the terminal via the downlink connection means 110 (step 601), the request determines whether the communication is data communication by the PC terminal or voice communication by the telephone terminal (step 602). ).

In the case of data communication (data of step 602), call processing for VC connection of the ATM network is performed with the service category being UBR, and instructions are given to the cell assembling / disassembling means 130 and the cell storing means 140 (step 6).
04).

In the case of voice communication (voice in step 602)
Determines whether a bandwidth resource can be secured as an ABR service category. (Step 605). If the resources can be secured (Y in step 605), after securing the band necessary for the voice communication, the VC of the ATM network is
The setting is stored in the cell assembling / disassembling means 130 and the cell storing means 140
To perform VC connection processing (step 604). If the resource cannot be secured (N in step 605), it notifies the downlink connection means 110 to reject the connection request for the voice communication.

When the connection control means 160 in communication receives a disconnection request from the terminal via the downlink connection means 110 (step 701), the connection control means 160 instructs the cell assembling / disassembling means 130 and the cell storage means 140. VC
A cutting process is performed (step 702).

Further, it is determined whether the request is from a PC terminal or a telephone terminal (step 703). In the case of data communication (data in step 703), the process is terminated as it is, and in the case of voice communication (step 703). Audio)
After releasing the secured bandwidth resource of the voice communication, the process ends.

Now, it is assumed that all of the telephone terminals 4 to 6 accommodated in the ATM access device 100 are performing voice communication via the ATM network according to the above procedure. At this time, when it is assumed that a bandwidth resource equivalent to 128 kbps is used in the voice communication, as shown in FIG. 9, the entire bandwidth of the ATM network connected to the ATM access device is 512 kbps.
128 kbps by three VCs of voice communication among s
X3 = 384 kbps bandwidth resources are secured. A for performing VC signaling processing
If 32 kbps is secured as a bandwidth resource for TM cells, the bandwidth of VC2 that PC terminals 1 to 3 can use for data communication is only equivalent to 96 kbps (state A).

At this time, the sound / non-speech determining unit 12 in the communication monitoring unit 120 provided in the ATM access device 100
2, VC3 to VC, which are voice communications of the telephone terminals 4 to 6
The silent state of the voice communication of No. 5 is monitored (step 80).
1). Here, if a silent state is detected in the voice communication of VC3 (Y in step 801), the information "VC3 = silence" is notified to the resource management unit 161 in the connection control means 160 (step 802).

The resource control unit 161 reduces the bandwidth resource of the VC3, secures the reduced bandwidth as a UBR bandwidth resource (step 803), and transmits the bandwidth resource change information to the cell assembling / disassembling means 130 and the signaling processing unit. 162. Here, VC
It is assumed that the band of No. 3 is changed from 128 Kbps to 16 kbps.

The cell assembling / disassembling means 130 suspends the cell formation of the voice communication packet of VC3, and furthermore, the ER (Explict Rate) value in the RM cell format and the AI (Acti
ve Indicaion) value. Signaling processing unit 16
In 2, the cell storage means 140 is notified of the change of the cell transfer rate of each buffer based on the notified information (step 804). Here, VC3 is equivalent to 16 kbps, VC3
2 is equivalent to 208 kbps.

Buffer management unit 1 in cell storage means 140
45 transfers the cell in accordance with this notification.
As shown in (3), when the VC3 is in a silent state, the bandwidth of the VC2 that can be used by the PC terminals 1 to 3 for data communication is equivalent to 208 kbps (state B).

At this time, the VC discarded due to the interruption of cell formation
Since the voice communication packet of No. 3 is a voice communication packet in a silent state, there is no problem in communication. In this state, a connection request for voice communication from a new terminal is sent to the signaling processing unit 16.
The call is rejected by the call admission control of 2.

When the sound / non-sound determining unit 122 detects a sound state of the voice communication of the VC3 (Y in step 805),
The information “VC3 = voiced” is sent to the connection control unit 1
60 is notified to the resource management unit 161 (step 8).
06). The resource management unit 161 releases the UBR bandwidth resource secured in step 803 and allocates it to the VC3 bandwidth resource.

The band resource change information includes the cell assembly /
The signal is notified to the decomposing unit 130 and the signaling processing unit 162, and the bandwidth of the VC3 returns to 128 Kbps. The cell assembling / disassembling means 130 restarts the VC3 voice communication packet into cells and changes the ER (Explict Rate) value and the AI (Active Indicaion) value in the RM cell format.

The signaling processing unit 162 notifies the cell storage unit 140 of a change in the cell transfer rate of each buffer based on the notified information (step 804). Here, VC3 is equivalent to 128 kbps, VC2 is 96 kbps
s. The buffer management unit 145 in the cell storage unit 140 transfers the cell according to this notification, and thus returns to the state of FIG. 9 again. (State A) FIG. 12 is a block diagram of the ATM access device according to the second embodiment of the present invention. In the second embodiment, the downlink connection means 210 of the ATM access device 200 accommodates CT (computer telephony) terminals 7 to 9 which handle both voice and data communications. Each of the CT terminals 7 to 9 has an ATM cell conversion function in the terminal, and performs voice communication and data communication via the ATM network by connecting to the ATM access device 200. Downlink connection means 210
Extracts an ATM cell that accommodates the plurality of CT terminals 7 to 9 and performs data or voice ATM communication.

The communication monitoring means 220 is a communication terminal that transmits a signal to the ATM network from a CT terminal connected to the downlink line.
Among the TM communication traffic, the valid / invalid state of the communication traffic which is the high-priority traffic is monitored, and the valid / invalid information is notified to the connection control means 260.

The cell assembling / disassembling means 130 assembles / disassembles a cell for performing a VC signaling signal or a flow control signal of a connected VC band between the CT terminal and the ATM network. The cell accumulating unit 140 accumulates ATM cells in buffers of different priorities according to an instruction from the connection control unit 260.

The connection control means 260 performs a call admission control for adjusting quality requirements and a signaling process for setting a VC between the CT terminal and the ATM network prior to the ATM communication. It also manages the bandwidth resources of the ATM network which is the uplink line,
At the time of TM network congestion or valid / invalid information from the communication monitoring means 220, the flow control of the VC during communication is performed using the RM cell.

The uplink connection means 150 connects to the ATM network and transfers ATM cells. For example,
Connect to a public ATM network with a 512 kbps bandwidth contract.

Next, the details of each block in the second embodiment will be described. However, the blocks not described here are the same as the blocks in the first embodiment of the present invention. Further, also in the second embodiment,
Among a plurality of service categories in the ATM communication, voice communication is performed in an ABR (Available Bit Rate) service, and data communication is performed in a UBR (Unspecified Bit Rate) service category.

FIG. 13 is a block diagram showing an example of the downlink connection means 210 according to the second embodiment of the present invention. The downlink connection means 210 has an ATM interface 211 for connecting to a CT terminal.
The M cell extraction unit 212 extracts ATM cells for data or voice communication. These functions are, for example, communication LS
I and memory.

FIG. 14 is a block diagram showing an example of the communication monitoring means 220 according to the second embodiment of the present invention. The communication monitoring means 220 is provided by the downlink connection means 2
The ATM cell for voice communication, which is the high-priority traffic, is selected from the ATM cells from 10 and the cell disassembly unit 221 generates a voice communication packet. The generated voice communication packet is digital-to-analog converted by the voice decoder 121,
The sound / silence determination unit 122 detects a sound / silence state. The detection result is notified to the connection control means 260. These functions can be realized by, for example, a cell conversion device and a voice CODEC device.

FIG. 15 is a block diagram showing an example of the connection control means 260 according to the second embodiment of the present invention. In FIG. 15, the resource management unit 161
Manages the bandwidth resources of the ATM network, and secures the VC bandwidth resources of the ABR in the ATM network which is the uplink line according to the call admission control information of the voice communication from the signaling processing unit 262. Also, when the ATM network is congested or voice communication is in a silent state, the VC that is communicating using the RM (resource management) cell is used.
Is performed.

For example, audio / voice from communication monitoring means 220
In accordance with the silence information, the band resource secured by the corresponding voice communication VC is controlled. Signaling processing unit 262
Is connected to the CT terminal via the cell assembling / disassembling means 130 and A
Prior to the ATM communication, a call acceptance control for adjusting a quality request and a signaling process for setting a VC are performed with the TM network. Resource management unit 1
In accordance with the instruction at 61, the cell transfer means 140 is notified of the cell transfer rate of each buffer. These functions can be realized by, for example, a central processing unit (CPU).

Next, an example of the operation at the start and end of communication according to the second embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

When the connection control means 260 receives a connection request from the CT terminal via the cell assembling / disassembling means 130 (step 601), it determines whether the request is data communication or voice communication (step 602).

In the case of data communication (data in step 602), call processing for VC connection of the ATM network is performed with the service category being UBR, and instructions are given to the cell assembling / disassembling means 130 and the cell storing means 140 (step 60).
4).

In the case of voice communication (voice in step 602)
Determines whether a bandwidth resource can be secured as an ABR service category. (Step 605). If the resources can be secured (Y in step 605), after securing the band necessary for the voice communication, the VC of the ATM network is
The setting is stored in the cell assembling / disassembling means 130 and the cell storing means 140
To perform VC connection processing (step 604). If the resource cannot be secured (N in step 605), the cell assembling / disassembling means 130 is notified to reject the connection request for the voice communication.

When connection control means 260 under communication receives a disconnection request from the CT terminal via cell assembling / disassembling means 130 (step 701), it instructs cell assembling / disassembling means 130 and cell storage means 140. And V
C cutting processing is performed (step 702).

Further, it is determined whether the request is data communication or voice communication power (step 703). If the request is data communication (data of step 703), the process is terminated. If voice communication (voice of step 703) is secured, the request is secured. After releasing the bandwidth resource of the voice communication that has been performed, the process ends.

Now, it is assumed that all the CT terminals 7 to 9 accommodated in the ATM access device are performing voice communication via the ATM network in accordance with the above procedure. At this time, when it is assumed that a bandwidth resource corresponding to 128 kbps is used in the voice communication, as shown in FIG.
512 kbps ATM network to connect to
128 kbps by three VCs of voice communication
This means that a bandwidth resource equivalent to 3 = 384 kbps is secured. AT for performing VC signaling processing
If 32 kbps is secured as a bandwidth resource for the M cell, the VC2 that can be used by the CT terminals 7 to 9 for data communication has only a bandwidth of 96 kbps (state A).

At this time, the sound / non-sound determining unit 12 in the communication monitoring means 220 provided in the ATM access device 200
In VC2, VC3 to VC, which are voice communications of CT terminals 7 to 9,
The silent state of the voice communication of No. 5 is monitored (step 80).
1). Here, if a silent state is detected in the voice communication of VC3 (Y in step 801), the information "VC3 = silence" is notified to the resource management unit 161 in the connection control means 260 (step 802).

The resource control section 161 reduces the bandwidth resource of the VC3, secures the reduced bandwidth as the bandwidth resource of the UBR (step 803), and transmits the bandwidth resource change information to the cell assembling / disassembling means 130 and the signaling processing section. 262. Here, VC
It is assumed that the band of No. 3 is changed from 128 Kbps to 16 kbps.

The cell assembling / disassembling means 130 discards the ATM cells of the VC3 voice communication, as well as the ER (Explict Rate) value and the AI (Active I) in the RM cell format.
ndicaion) Change the value. The signaling processing unit 262 notifies the cell storage unit 140 of a change in the cell transfer rate of each buffer based on the notified information (step 80).
4). Here, VC3 is equivalent to 16 kbps, and VC2 is equivalent to 208 kbps.

Buffer management unit 1 in cell storage means 140
45 transfers the cell in accordance with this notification, so that VC3
Is in a silent state, as shown in FIG. 10, the bandwidth of the VC2 usable by the CT terminal for data communication is 208 kbps.
(State B).

At this time, since the ATM cells of the VC3 discarded are silent voice communication packets, there is no problem in communication. Further, in this state, a connection request for voice communication from a new terminal is rejected by the call reception control of the signaling processing unit 162.

When the sound / non-sound determining unit 122 detects a sound state of the voice communication of the VC3 (Y in step 805),
The information “VC3 = voiced” is sent to the connection control unit 2
60 is notified to the resource management unit 161 (step 8).
06). The resource management unit 161 releases the UBR bandwidth resource secured in step 803 and allocates it to the VC3 bandwidth resource. The band resource change information is notified to the cell assembling / disassembling means 130 and the signaling processing unit 262. Here, the bandwidth of VC3 returns to 128 Kbps.

In the cell assembling / disassembling means 130, the ATM cell of VC3 is passed and the ER in the RM cell format is
(Explict Rate) value and AI (Active Indicaion) value are changed. The signaling processing unit 262 notifies the cell storage unit 140 of a change in the cell transfer rate of each buffer based on the notified information (step 804). Where V
C3 is equivalent to 128 kbps, and VC2 is equivalent to 96 kbps.

Buffer management unit 1 in cell storage means 140
Since the cell 45 transfers the cell according to the notification, the state returns to the state of FIG. 9 again. (State A) In the embodiment of the present invention, voice communication is described as high-priority traffic and data communication is described as low-priority communication traffic. For example, video communication is considered as high-priority traffic, and data communication is considered as low-priority communication traffic. Is also good.

Further, it has been described that the ATM service category of ABR is used for high-priority communication traffic and UBR is used for low-priority communication traffic, and VC flow control is performed using RM cells. Has a bandwidth resource management (VC flow control) means having the same function as the RM cell,
The high-priority communication traffic may be a service category such as CBR (constant bit rate) or VBR (variable bit rate).

As the communication monitoring means for the high-priority communication traffic, the valid / invalid state is determined based on the silent / speech state of the voice communication. For example, the telephone terminal has a means for notifying the hold state during communication. Then, the communication monitoring means may determine the valid / invalid state by the hold detection. Even in the case where moving image communication is considered as high-priority communication traffic, the communication monitoring means may determine the valid / invalid state by detecting the temporary stop if the terminal has a means for notifying the pause state during communication. .

Also, as a downlink connection means, a PC
Although the connection with the terminal was an Ethernet interface,
Not limited to this, for example, RS-232C, USB, IEEE
A general-purpose serial interface such as E1394 may be used. Similarly, the connection with the telephone terminal is made by the ISDN interface, but is not limited to this, and may be an analog interface or a base station of a mobile phone or PHS.

[0085]

According to the present invention, the ATM access device has communication monitoring means for discriminating the voiced / silent state of voice communication which is high-priority traffic, and secures voice communication based on the silence information obtained here. Since the allocated band is temporarily allocated to the band for data communication, the communication time of data communication with a low communication priority accommodated in the ATM access device can be reduced.

[0086]

[Brief description of the drawings]

FIG. 1 is a block diagram of an ATM access device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a downlink connection unit according to the first embodiment of the present invention.

FIG. 3 is a block diagram of a communication monitoring unit according to the first embodiment of the present invention.

FIG. 4 is a block diagram of a cell storage means according to the first and second embodiments of the present invention.

FIG. 5 is a block diagram of a connection control unit according to the first embodiment of the present invention.

FIG. 6 is a flowchart showing an example of the operation of the connection control means at the start of communication.

FIG. 7 is a flowchart illustrating an example of an operation of a connection control unit at the end of communication.

FIG. 8 is a flowchart showing an example of the operation of the connection control means in the communication state according to the present invention.

FIG. 9 is an explanatory diagram showing a resource control table managed by the resource control unit of the present invention.

FIG. 10 is an explanatory diagram showing a resource control table managed by the resource control unit of the present invention.

FIG. 11 is an explanatory diagram illustrating an example of a format of an RM cell used in VC band flow control.

FIG. 12 is a block diagram of an ATM access device according to a second embodiment of the present invention.

FIG. 13 is a block diagram of a downlink connection unit according to the second embodiment of the present invention.

FIG. 14 is a block diagram of a communication monitoring unit according to the second embodiment of the present invention.

FIG. 15 is a block diagram of a connection control unit according to the second embodiment of the present invention.

FIG. 16 is a block diagram of a conventional ATM access device.

FIG. 17 is a block diagram of a conventional connection control means.

[Explanation of symbols]

 100, 200, 400 ATM access device 110, 210 Downlink connection means 111 Ethernet interface 112 ISDN interface 113 IP data extraction unit 114 PCM data extraction unit 120, 220 Communication monitoring unit 121 Voice decoder 122 Voice / non-voice determination unit 130 Cell assembly / Decomposition means 140 Cell storage means 141 Cell distribution section 142 Signaling cell buffer 143 ABR cell buffer 144 UBR cell buffer 145 Buffer management section 150 Uplink connection means 160, 260, 460 Connection control means 161, 461 Resource management section 162, 262 Signaling Processing unit 211 ATM interface 212 ATM cell extraction unit 221 Cell decomposition unit

Claims (9)

[Claims] An ATM access device that accommodates high-priority traffic and low-priority traffic, monitors high-priority traffic, and when valid information is not transferred to the high-priority traffic in use, the ATM of the traffic. An ATM access apparatus comprising means for temporarily allocating a bandwidth resource secured by a VC (virtual connection) used for communication to a bandwidth of low priority traffic. 2. The ATM access device accommodates a telephone terminal and a PC terminal, wherein the high-priority traffic is voice from the telephone terminal and the low-priority traffic is data from the PC terminal. The ATM access device according to claim 1, wherein: 3. The ATM access device accommodates a CT terminal that handles both voice and data communication, wherein the high-priority traffic is voice from the CT terminal and the low-priority traffic is the CT terminal. 2. The ATM access device according to claim 1, wherein the data is data from the ATM. 4. The ATM access device according to claim 2, wherein said means for monitoring high-priority traffic determines that valid information is not transferred when there is no sound. 5. A downlink connection means for accommodating a plurality of PC terminals and telephone terminals and extracting a data communication packet and a voice communication packet from respective communication traffic, and a terminal connected to the downlink connection means is an ATM network. Communication monitoring means for monitoring the valid / invalid state of communication traffic which is high-priority traffic among the communication traffic to be transferred to the communication control means, and notifying the validity / invalid information to the connection control means; and a data communication packet or Cell assembling / disassembling means for converting into ATM cells of a different VC for each voice communication packet, and assembling / disassembling an ATM cell of a VC signaling signal with the ATM network or a flow control signal of a VC being connected; / Connection of ATM cells from disassembly means to the connection Cell accumulating means for accumulating in internal buffers for different priorities in accordance with instructions from the control means; call admission control and VC for adjusting quality requirements between the PC terminal or telephone terminal and the ATM network prior to ATM communication. Performs the signaling process for setting up the ATM network, manages the bandwidth resources of the ATM network which is the uplink line, and communicates using the RM cell according to the congestion of the ATM network and the valid / invalid information from the communication monitoring means. An ATM access device, comprising: the connection control means for performing flow control of the VC; and an uplink connection means for connecting to the ATM network and transferring an ATM cell. 6. The communication monitoring means includes means for digital-to-analog conversion of the voice communication packet, which is high-priority traffic, by a voice decoder, and detecting the presence / absence of a sound / non-speech state of the analog-converted voice signal. 6. The ATM access device according to claim 5, wherein said ATM access device is constituted by a sound / non-sound determining unit for notifying a connection control unit. 7. The connection control means according to claim 1, wherein
The ABR manages bandwidth resources of the M network and transmits ABR to the ATM network which is an uplink line according to call admission control information of voice communication from the signaling processing unit.
And a resource management unit for controlling the bandwidth resource secured by the VC of the corresponding voice communication according to the sound / non-sound information from the communication monitoring means, and the downlink connection means. The PC
A terminal or a telephone terminal and the ATM network via the cell assembling / disassembling means perform call admission control for adjusting quality requirements and signaling processing for setting a VC prior to ATM communication, and perform the resource processing. 6. A signaling processing unit for notifying the cell storage unit of a cell transfer rate of each internal buffer according to an instruction of a management unit.
The ATM access device of any of the preceding claims. 8. A plurality of CT (computer / telephony) terminals that handle both voice and data communication and have an ATM cell conversion function and perform voice communication and data communication via an ATM network. A downlink connection means for extracting an ATM cell for performing voice ATM communication;
Communication monitoring means for monitoring the valid / invalid state of communication traffic which is high-priority traffic among ATM communication traffic to be transferred to the TM network, and notifying the validity / invalidity information to the connection control means; the CT terminal and the ATM; A cell assembling / disassembling means for assembling / disassembling a cell for performing a VC signaling signal or a flow control signal of a VC band being connected to / from a network; Cell accumulation means for accumulating data in a buffer; and an AT between the CT terminal and the ATM network.
Prior to the M communication, it performs call admission control for adjusting quality requirements and signaling processing for setting a VC, manages bandwidth resources of the ATM network which is an uplink line, and monitors the ATM network during congestion and the communication monitoring. The connection control means for performing flow control of a communicating VC using RM cells based on valid / invalid information from the means; and an uplink connection means for connecting to the ATM network and transferring the ATM cells. An ATM access device, characterized in that: 9. A cell decomposer for selecting a voice communication ATM cell which is high priority traffic from ATM cells from the downlink connection means and generating a voice communication packet, wherein the communication monitoring means includes: A voice decoder for digital-to-analog conversion of a voice communication packet, and a voice / silence determination unit for detecting the voice / non-voice state of the analog-converted voice signal and notifying the connection control unit of the voice signal. The ATM access device according to claim 8, wherein: