JPS6268353A - Voice packet communication system - Google Patents

Abstract

PURPOSE:To send efficiently a voice while keeping the naturality and to ensure the control such as call setting or release by setting a call logic link to send a packet for call setting/release and setting a voice logic link to send the voice packet separately. CONSTITUTION:In applying call input operation from a key input section 22 by a packet terminal device 1a, a control section 11 generates a call packet where a control field 61 is inserted with call request information CR and gives a number (n) of the logic link for call setting to a link number field 63. After the input is stored once in a buffer 14, the result is sent from a packet transmission/reception section 15 to a communication line 24. On the other hand, a relay node 3 uses a packet transmission/reception section 33 to receive the calling packet and stores it once in the buffer 24 and when a control section 31 discriminates no error, the information of the control field 61 is decoded. When it is recognized to be a call request packet, after the logic link (n) for call setting and a logic link (n+1) for voice are set respectively, the reply packet is generated at first and returned to the terminal device 1a from the packet transmission/reception section 33 via the logic link (n).

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a voice packet communication system that packetizes and transmits voice signals.

[Technical background of the invention and its problems]

Conventionally, as a communication method, information is divided into blocks of a certain length, and each block is transmitted with a header containing regulatory information necessary for transmission such as destination information and error control information. Although the packet communication method is known,
In recent years, attempts have been made to packetize and transmit not only data but also voice signals. If this audio packet communication method is realized, it will be possible to perform operations such as sending only the active part of the audio signal and not sending the silent part, compared to the circuit switching method that transfers information after the line is connected. transmission efficiency can be greatly increased.

However, in general, packet communication systems perform communication II! in which a relay station checks the received packet for errors and retransmits it if there is an error. J 1111
method is adopted. For this reason, information is retransmitted every time an error occurs, and when information is retransmitted in this way, the audio reproduction timing on the receiving side is partially delayed in the case of voice communication, which reduces the naturalness of the voice. This is very undesirable as it will damage the property.

Therefore, it is conceivable to transmit all packets without acknowledgment of delivery, but although this improves the naturalness of the voice signal, it also has the disadvantage that, for example, if a packet for call setup is lost in the middle of the transmission path. Since the call setup request is not transmitted to the receiving side, there is a drawback that call setup cannot be performed reliably.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a voice packet communication system that can efficiently transmit voice signals while preserving their naturalness, and can reliably control call setup and release.

[Summary of the invention]

In order to achieve the above object, the present invention sets up a paging logical link for transmitting call setup/release packets between the sender and the receiver for each call, and also transmits voice packets separately from this paging logical link. A logical link for audio is set up to ensure that the paging packet is transmitted reliably by performing communication control with send and acknowledge on the above-mentioned paging logical link, and communication control without delivery confirmation is performed on the logical link for audio. By doing so, retransmission of audio packets is avoided.

[Embodiments of the invention]

FIG. 1 is a schematic configuration diagram of a communication system to which a voice bucket 1 communication method is applied in one embodiment of the present invention. 2c are connected via a plurality of relay nodes 3, 4.5.

Each of the packet terminals 1a to 1c and 2a to 2C is equipped with a control section as shown in FIG. The interface 13 receives and passes signals between the control section 11 and the handset 21, the key input section 22 for inputting destination information, etc., and the buzzer 23 for calling notification.

The packet transmitting/receiving unit 15 sends the transmission packets assembled by the control unit 11 to the communication line 24 and the communication port FA2.
Each of the packets that arrive through the packets are received through 4. Furthermore, the buffer 14 temporarily stores the transmission packet and the reception bucket 1- in order to adjust the timing of transmission and reception.

By the way, the control unit 11 controls the microcomputer
Each unit has 14 functions as shown in FIG. In other words, its function is that of the input/output control means 11 that inputs and outputs signals to and from the handset 21, key input unit 22, and buzzer 23 via the interface 13.
a, a packet assembly and disassembly means 11b for assembling and disassembling packets during transmission and reception, and a packet transmission and reception section 1
Packet transmission/reception control means 11C that performs control over 5
, a packet retransmission control means 11d that retransmits a packet when a response packet is not returned even after a certain period of time has elapsed after transmission, a logical link setting means 11e, and a communication control mode setting means 11f. Of these, the logical link setting means 11e includes a paging logical link and a voice bucket 1 for transmitting packets for call setup and release during transmission and reception.
This is to set up logical links for each tone for transmitting -. Further, the communication control mode setting means 11f
At the time of transmission and reception, a communication control mode with delivery confirmation or a communication control mode without delivery confirmation is selectively set in conjunction with the setting of the logical link.

On the other hand, the relay node 3.4.5, as shown in FIG.
It is composed of a buffer 34.

Each packet transmitting/receiving unit 33, 35 transmits and receives packets between adjacent packet terminals or relay nodes via the communication line 24. Also, the buffer 34
is used to temporarily store transmitted packets and received packets for synchronization of timing during transmission and reception.

By the way, the control unit 31 controls the packet terminals 18 to 1c,
Similar to the control section 11 of 2a to 2C, a 74-chrome computer is used as the main control section, and its functions include bucket 1 to transmission/reception control means 31a as shown in FIG. a packet response control means 31b for occasionally returning a response packet; a logical link setting means 31c for selectively setting a logical link for a call and a logical link for voice according to the contents of a received packet; and setting of the logical link. It has communication control mode setting means 31 (j) for selectively setting a communication control wholesale mode with delivery confirmation and a communication control mode without delivery confirmation in connection with this.

FIG. 6 shows the structure of a packet used in the above system. This packet has a header consisting of a start flag SF, destination address DA, source address SA, and control field 61 added to the head of a data field 60. At the same time, an error check code FC8 and an end flag EF are added to the tail of the data field 60, respectively. Here, the control field 61
field 62 contains packet type information indicating the fi class of the packet; U and the sequence number of the packet.
In addition to , information 63 representing a logical link number is inserted.

Next, the voice packet communication system of this embodiment will be explained based on the above configuration. Note that an explanation will be given here taking as an example a case where an audio signal is transmitted from the packet terminal 1a to the packet terminal 2c.

When a manual call operation is performed by the key manual unit 22 at the packet terminal 1a, the packet terminal 1a creates a call packet with call request information CR inserted into the control field 61 in response to the call request by the control unit 11. and the link number field 6 of these calling packets 1 to (CR packet)
3 is assigned the number n of the logical link for call setup. After this calling packet (FIG. 7(a)) is temporarily stored in the buffer 14, it is sent to the communication line 24 from the packet transmitting/receiving section 15.
Send to. Also, at this time, the control unit 11 sets the communication control mode using the logical link n for call setting to a mode with delivery confirmation.

On the other hand, the relay node 3 to which the calling packet was sent receives the calling packet through the packet transmitting/receiving section 33 and buffers it. 24, and then the controller 31 determines whether there is a transmission error. If it is determined that there is no error, the information in the control field 61 is decoded. When the incoming bucket i is recognized as a voice call request packet,
After setting the logical link itself for call setup and the logical link n+1 for voice, first, a response packet (RR packet) is created and sent from the packet transmitting/receiving unit 33 to the logical link n+1.
It is then sent back to the calling terminal 1a.

Note that if a transmission error is detected, no response packet is returned. On the other hand, the calling terminal 1a sets the communication control mode of the logical link n for call setup to the mode with delivery confirmation as described above, so even if a certain period of time has elapsed after sending the packet, If a response packet is not returned, it is determined that an error has occurred and the calling packet is retransmitted. Therefore, the calling packet from the calling terminal 1a is reliably sent even if the condition of the communication line is poor. Also, relay node 3
After completing the return of the response packet, the calling packet stored in the buffer 34 is sent from the packet transmitting/receiving section 35 to the next relay node 4 via the logical link n for call setting.

Similarly, calls are made between relay nodes 3 and 4, between 4.5 questions, and between relay node 5 and packet terminal 2C, while communication control with delivery confirmation is performed via logical link n for call setup. The packet is transferred.

Now, when the calling packet reaches the packet terminal 2c which is the destination terminal in this way, this packet terminal 2C receives the calling packet by the packet transmitting/receiving section 15, temporarily stores it in the buffer 14, and then the control section 11 to determine the type of packet. Based on this determination, if it is a call request, interface 1
A calling signal is output to the buzzer 23 via the telephone 3, thereby notifying the subscriber that an incoming call has occurred. When the subscriber responds to this by, for example, operating a predetermined key on the key manual unit 22, the packet terminal 2c uses the control unit 11 to input the incoming call reception information CA and the logical link number n for call setup into the control field 61. An incoming call acceptance packet (CA packet) inserted in each case is created, and this incoming call acceptance packet (FIG. 7(b)) is sent from the bucket 1 to the transmitter/receiver 15 to the relay node 5 using the logical link n for call setup. Forward.

Note that this transfer is a transfer of packets for call setup, so
As the communication control mode, a mode with delivery confirmation is applied. The incoming call acceptance packet sent from the packet terminal 2C is sent to the originating terminal in a communication control mode with delivery confirmation via the reverse route to that for the outgoing call packet and through the logical link n for call setup. Packet terminal 1 is
transferred to a.

In this way, a communication path is established between the packet terminal 1a and the packet terminal 2C.

After this communication path is established, for example, when a subscriber inputs voice using the handset 21 at the packet terminal 1a, the voice signal is packetized by the controller 11 and then sent to the buffer 1.
4, and then the audio logical link n+
1 and then sent from the packet transmitting/receiving unit 15 to the relay node 3. Note that the control field 61 of this data packet
As shown in FIG. 7(C), the information DT indicating that the data is data and the logical link number n+1 for audio are inserted.

When this data packet arrives, the relay node 3 receives the data packet by the packet transmitting/receiving unit 33, temporarily stores it in the buffer 34, and then uses the logical link number inserted in the control field of the data packet by the control unit 31. Determine the communication control mode. Since the audio logical link number n+1 has now been inserted as the logical link number, it is determined that the communication control mode does not require delivery confirmation, and the data packet is stored in the buffer 34 and transferred to the logical link n+1. through the packet transmitting/receiving section 3
Send it as is from 5. Similarly, relay node 4.5
Also, the data packet is connected to the audio logical link n+1
, and then transferred in order by correspondence (company) mode without delivery confirmation. Therefore, even if an error occurs during transmission, the data packet will not be retransmitted.

When the data bucket 1- arrives at the packet terminal 2C, the packet terminal 2C accumulates each data packet in the buffer 14 in the order of arrival, and then assembles the data packets using the control unit 11 to reproduce an audio signal. It is output to the handset 21 via the interface 13 and sent out as voice. In this way, audio is transmitted from the packet terminal 1a to the packet terminal 2C. Similarly, audio is transmitted from the bucket terminal 2 to the packet terminal 1a via the audio logical link n+1 for each data packet in a communication control mode without delivery confirmation. Figure 7 (
d) shows the structure of the data packet.

After R, when the call ends and, for example, the subscriber of the packet terminal 2C uses the key manual unit 22 to terminate the call, the packet terminal 2C uses the control unit 11 to send the 1u old request information CQ and the logical link number n for release. The recovery request packet (CQ packet) inserted into the control field 61 is shown in FIG.
) and send this packet using logical link n for release. On the other hand, when the controller 11 confirms the recovery request packet, the bucket 1 and the terminal 1a to which this recovery request packet has arrived turn off the I! signal in the control field 61 as shown in FIG. Returns a packet with Fi confirmation information CF and logical link number n for release inserted,
After that, the standby mode returns to the state. Thus, the series of call operations is completed. Note that the transmission of the recovery request packet and disconnection confirmation packet described above is performed in a communication control mode with delivery confirmation. Therefore, the transmission of packets related to this release control is also performed reliably regardless of the state of the transmission path, as in the case of the call origination control.

As described above, in this embodiment, call setup and release packets are transmitted through logical link n to which communication control mode with delivery confirmation is applied, and voice packets are transmitted by communication control mode without delivery confirmation. Since the transmission is performed using the logical link n+i, call setting and release packets can always be reliably transmitted regardless of the state of the communication line, and thereby reliable line control can be performed. Further, even if a transmission error occurs during the transmission of a voice packet, the voice packet is not retransmitted, so there is no delay in voice reproduction caused by retransmission, and the naturalness of the voice can be maintained at a high level. Note that by not performing the above retransmission, if an error occurs, the audio of the data packet will be lost without being played back, but in the case of audio, the data length sent in each data packet is generally short, so this is not practical. There is no major problem, and converting the delayed and retransmitted data into audio only increases the distortion of the sound. Furthermore, although two logical links must be set, there is generally a sufficiently large number of logical links, so this does not pose a major problem in practice.

Note that the present invention is not limited to the above-mentioned embodiments, and may be applied to, for example, a local area network (LAN) system whose main purpose is communication within the same building, in addition to a general wide-area packet communication network. good. In addition, the configurations of the terminal devices and relay stations, the functions of their control units, etc. can be modified in various ways without departing from the gist of the present invention.

〔Effect of the invention〕

As described in detail above, according to the present invention, a call logical link is set for transmitting call setup/release packets between the sender and the receiver for each call, and voice packets are A logical link for voice is set up to transmit the call packet, and the logical link for call performs communication control with delivery confirmation to ensure the transmission of the call packet, and the logical link for voice performs communication without confirmation of delivery. By controlling voice packets so as not to retransmit them, voice signals can be efficiently transmitted while preserving their naturalness, and call setup/release can be controlled reliably. Voice bucket 1 - can provide a communication method.

[Brief explanation of drawings]

The figures are for explaining a voice packet communication system according to an embodiment of the present invention. Figure 1 is a schematic diagram of a packet communication system to which the same system is applied, and Figure 2 is a diagram showing the configuration of a packet terminal in the system. FIG. 3 is a block diagram showing the configuration of the relay node, FIGS. 4 and 5 are block diagrams showing the functions of the dovetails of the packet terminal and the relay node, respectively, and FIGS. 6 and 7 are block diagrams showing the configuration of the relay node. (a) - (f
) are schematic diagrams showing the configuration of buckets 1 to 1, respectively. 18-ic, 2a-2C...Packet terminal, 3.4.
5... Relay node, 11... Control unit of packet terminal, 12.32... Bus, 13... Interface,
14.34...Buffer, 15.33.35...Packet transmission/reception unit, 21...
Transceiver, 22... Key human power section, 23... Buzzer, 2
4... Communication line, 11a... Input/output control means, 11
b...Packet assembly/disassembly means, 110.31b...Packet transmission/reception control means, 11d
...Packet retransmission control means, 118.31C...Logical link setting means, 11f, 3
1d... Communication control mode setting means, 61... Control field, 62... Packet type information and sequence number field, 63... Logical link number information. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 3 ↓ , j4' J) 3.4.5 Figure 4 Figure 5 11' 6th and 7th

Claims (1)

[Claims] In a voice packet communication method in which voice signals are packetized and transmitted between terminal devices, a call logical link for transmitting call setup/release packets between the sender and receiver for each call;
A voice logical link for transmitting voice packets is set respectively, and the call logical link performs communication control with delivery confirmation, and the voice logical link performs communication control without delivery confirmation. Characteristic voice packet communication method.