JP2006135553A - Communication terminal device and data communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication terminal device and a data communication method by which the time required up to the establishment of communication can be shortened, when a quality deterioration factor is present on a line such as a public line. <P>SOLUTION: A connection modulation mode is changed in an analog line by making a forcible fallback from the ITU-T recommendation V.90 to the ITU-T recommendation V.34 in phases 3 and 4 of the ITU-T recommendation V.90 and a communication rate decreases, but the time required up to a connection as a communication terminal device can be shortened and a stable connection which is free of disconnection can be obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a communication terminal device and a data communication method, and in particular, a modem device having a function of performing communication based on a communication procedure according to ITU-T recommendations V.8, V.34 and V.90, and a communication including a host The present invention relates to a communication terminal device such as a terminal device and a data communication method.

The communication terminal apparatus establishes data transmission in accordance with designation and exchange of communication capabilities of both the calling side and the called side. The capability exchange is performed according to the procedure of the first ITU-T recommendation V.8 of communication (see FIG. 1 for the detailed procedure).
FIG. 1 is an explanatory diagram showing ITU-T recommendation V.90 phase 1 (ITU-T recommendation V.8).
In the figure, “analog modem” indicates a mode connected to a telephone line, and “digital modem” means a mode of a modem used in a server or the like.
Information that is exchanged between communication terminals, and the speed and modulation method that can be used by both parties in common are defined by the recommendations of the International Telecommunication Union-Standardization Sector (ITU-T), for example, V.90, V.34, V. 32bis, V.32, V.22bis, V.22, V.21, etc. speed and modulation system "standards will be determined.

  Here, as a communication terminal device, during execution of the procedures of ITU-T Recommendations V.8 and V.34, switching to T.30 according to the estimated line state, and transmitting / receiving desired data at a low communication cost Yes (see, for example, Patent Document 1).

  The communication device described in Patent Document 1 is a communication device that can communicate with a counterpart communication device in accordance with the procedures of ITU-T recommendations T.30, V.8, and V.34. When a communication line is connected to the called station and the ITU-T recommendation V.8 procedure is executed, the call signal from the called station is transmitted within a predetermined transmission time t1 of the CM signal transmitted by the communication device. A detecting means for detecting a JM signal and a half-duplex communication operation according to the ITU-T recommended T.30 procedure by interrupting the execution of the recommended V.8 procedure when no JM signal is detected within the CM transmission time t1. And a control means for executing.

  However, since the communication device described in Patent Document 1 interrupts the execution of the ITU-T recommendation V.8 procedure and follows the recommendation T.30 procedure, communication is established when there is a quality degradation factor on the line. It takes time to complete.

On the other hand, in the case of ITU-T recommendation V.90 (the above ITU-T recommendation V.8 indicates phase 1 in ITU-T recommendation V.90), the signal procedure conforms to the selected common mode (modulation method). Up to data transmission, four sessions called phases are established (refer to FIGS. 1 to 4 for details of phases 1 to 4).
2 is an explanatory diagram of ITU-T recommendation V.90 phase 2, FIG. 3 is an explanatory diagram of TTU-T recommendation V.90 phase 3, and FIG. 4 is an explanatory diagram of ITU-T recommendation V.90 phase 4.

  Phases of ITU-T recommendation V.90 exist from 1 to 4, and connection information necessary for establishment, for example, function information on communication capabilities of the sending and receiving modems, and between the sending and receiving modems The parameters trained by the channel quality and the channel probing result can be obtained in phase 2.

  FIG. 5 is an enlarged view of part 3-a of FIG. 3, and is an explanatory diagram of a method of fallback after the end of the phase 3 training. FIG. 6 is an enlarged view of the 4-a portion of FIG. 4, and is an explanatory diagram of a method of falling back when transmitting a CP signal in phase 4. FIG.

  Similarly, it is defined that function selection information, a modulation mode, and a modulation parameter can be acquired as function information. According to ITU-T recommendation V.90, after receiving the INFO1d signal (see FIG. 2) transmitted by the digital modem, the analog modem transmits INFO1a (Tables 1 to 3).

When an analog modem generates an INFO1a signal, it normally uses parameters trained according to the line quality between the originating modem and the receiving modem and the line probing result. The modulation method determined by ITU-T recommendation V.8 Adopted.
JP-A-11-127328

  However, the connection is started in the ITU-T recommendation V.90 mode selected in the ITU-T recommendation V.8, and ITU-T recommendation V.90 phase 3 (see FIG. 3 for the detailed procedure), ITU-T Proceed to Recommendation V.90 Phase 4 (see Figure 4 for detailed procedure), and when the data transmission phase is reached, the line condition is poor (for example, privately) at the speed selected by ITU-T Recommendation V.90. In some cases, it is not possible to connect in the ITU-T recommendation V.90 mode initially selected in ITU-T recommendation V.8. In that case, the ITU-T recommendation establishes a connection that seems to be optimal by re-training between both communication terminals from the procedure of ITU-T recommendation V.90 Phase 2 (see Figure 2 for detailed procedure) again. It was.

When connecting to ITU-T Recommendation V.90, proceed to Phases 1, 2, 3, and 4. If connection is not possible due to line quality degradation during the procedure, recovery to Phase 2 is recovery. To tell. Naturally, when the recovery mechanism defined in the recommendation works, the number of steps required to complete the connection increases, and it takes time to connect and burdens the user.
Actually, in the case of the ITU-T recommendation V.90 modem, after dialing, it reaches the data mode via Phase 1, Phase 2, Phase 3, and Phase 4. If a connection could not be established at this point, it would be necessary to start again from Phase 2 in which INFO information (Tables 1 to 3) is exchanged and probing is performed again, and it took a long time to connect.

The recovery mechanism uses the INFO1a signal in phase 2 (see section 2-a in FIG. 2) from the beginning of phase 3 (see FIG. 3) to the ITU-T recommendation V.34 from the ITU-T recommendation V.90 mode. A method of falling back to the mode (changing the modulation method) is known.
This is because when the line degradation is found from the probing result (including symbol rate value) of the INFO signal (Table 1 to Table 3) transmitted from the digital modem and the error value of the mounted equalizer, the analog modem The INFO1a signal transmitted from the ITU-T recommendation V.90 mode is changed to the bit definition when the ITU-T recommendation V.34 mode is selected to reduce the connection speed and improve the stable connection and connection time. It is a mechanism to do.

However, this recovery mechanism has the following problems.
A detailed determination cannot be made for the determination of the line status in phase 2 (not the determination of the line status at the actual transfer rate).
In addition, if the recovery mechanism works when the connection cannot be made after reaching the data mode, the connection procedure from Phase 2 must be followed again, which takes a long time to connect, and in the worst case, the recovery operation is repeated many times. Occasionally a connection cannot be established.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a communication terminal device and a data communication method capable of reducing the time required for establishing communication when there is a quality degradation factor on a line such as a public line. .

  In order to solve the above-mentioned problem, the invention described in claim 1 is a communication terminal device having a function of performing data communication, wherein a first transmission means for transmitting a procedure signal compliant with ITU-T recommendation V.8, an incoming call First receiving means for receiving a JM signal transmitted from the side, and identification detecting means for selecting an operation common mode based on a detection result of the first receiving means and indicating a recommended type to be connected A second communication unit having a second communication unit, a second transmission unit that transmits a procedure signal compliant with ITU-T recommendation V.90, and a second reception unit that receives a procedure signal transmitted from the called side ITU-T recommendation V.90 is selected as a common mode in the detection result of the ITU-T recommendation V.8 and the ITU-T selected in accordance with the signal degradation status of the connection line measured in phase 2 If it is determined that the connection cannot be made according to Recommendation V.90, the ITU-T recommendation from Phase 3 or Phase 4 Control means for switching to the ITU-T recommendation V.34 signal procedure earlier than the prescribed recovery procedure, third transmission means for transmitting a procedure signal compliant with ITU-T recommendation V.34, and transmission from the called side And a third communication unit having third receiving means for receiving the procedure signal to be transmitted.

  According to a second aspect of the present invention, in the first aspect of the present invention, when the procedure of the transmission signal TRN of the first communication unit is completed, the control means deteriorates the line condition and the ITU-T recommendation If it is determined that the connection cannot be established with V.90, the INFO data that forcibly falls back to the ITU-T recommendation V.34 mode is generated from the first communication unit, and recovery is performed. It is characterized in that it falls back after the end of training.

  According to a third aspect of the present invention, in the first aspect of the present invention, the control means causes the line condition to deteriorate during the procedure of the transmission signals CP and CP ′ of the first communication unit, and the ITU-T recommendation If it is determined that the connection cannot be established with V.90, the INFO data that forcibly falls back to the ITU-T recommendation V.34 mode is generated from the first communication unit, and recovery is performed. It is characterized in that a fallback is performed when the CP signal is transmitted.

  According to a fourth aspect of the present invention, in the data communication method for performing data communication between communication terminal devices, the first communication unit transmits a procedure signal compliant with ITU-T recommendation V.8, The JM signal to be transmitted is received, the operation common mode is selected based on the detection result of the first receiving means, the recommended type to be connected is indicated, and the second communication unit is ITU-T recommendation V.90. The control means receives the procedure signal transmitted from the called party, and the control means uses the detection result of the ITU-T recommendation V.8 as the common mode and the ITU-T recommendation V.90 If it is determined that it is possible to connect with the selected ITU-T recommendation V.90 according to the signal degradation status of the connection line measured in phase 2, and if it is determined that connection is not possible, then from phase 3 or phase 4 Switching to the ITU-T Recommendation V.34 signal procedure earlier than the recovery procedure defined in the ITU-T Recommendation, Send a procedure signal conforming to the ITU-T Recommendation V.34, characterized in that it receives a procedure signal transmitted from the called side.

  According to a fifth aspect of the present invention, in the invention according to the fourth aspect, when the procedure of the transmission signal TRN of the first communication unit is completed, the control means deteriorates the line condition and the ITU-T recommendation If it is determined that the connection cannot be established with V.90, the INFO data that forcibly falls back to the ITU-T recommendation V.34 mode is generated from the first communication unit, and recovery is performed. It is characterized in that it falls back after the end of training.

  According to a sixth aspect of the present invention, in the fourth aspect of the present invention, in the procedure of the transmission signals CP and CP ′ of the first communication unit, the control means deteriorates the line condition and the ITU-T recommendation If it is determined that the connection cannot be established with V.90, the INFO data that forcibly falls back to the ITU-T recommendation V.34 mode is generated from the first communication unit, and recovery is performed. It is characterized in that a fallback is performed when the CP signal is transmitted.

  By performing forced fallback from ITU-T recommendation V.90 to ITU-T recommendation V.34 in phases 3 and 4 of ITU-T recommendation V.90, the connection modulation mode is changed on the analog line, and the communication rate However, the time required for connection as a communication terminal device can be shortened, and a stable connection without disconnection can be obtained.

  An embodiment of the present invention is a communication terminal device having a function of performing data communication, and is transmitted from a callee side, a first transmission means for transmitting a procedure signal compliant with ITU-T recommendation V.8. A first communication unit having an identification detection unit that selects a common operation mode based on a detection result of the first reception unit and indicates a recommended type to be connected; A second communication unit having a second transmission means for transmitting a procedure signal compliant with ITU-T recommendation V.90, a second reception means for receiving a procedure signal transmitted from the called side, and an ITU- ITU-T recommendation V.90 is selected as a common mode in the detection result of T recommendation V.8, and connection cannot be established with ITU-T recommendation V.90 selected according to the signal degradation status of the connection line measured in phase 2 If ITU-T is determined earlier than the recovery procedure specified in the ITU-T recommendation from phase 3 or phase 4 Control means for switching to the signal procedure of notification V.34, third transmission means for transmitting a procedure signal in accordance with ITU-T recommendation V.34, and third procedure for receiving a procedure signal transmitted from the called side And a third communication unit having a receiving means.

  Here, when the control means determines that the line condition deteriorates and the connection cannot be made according to ITU-T recommendation V.90 when the procedure of the transmission signal TRN (training signal) of the first communication unit is completed, By creating INFO data that is forced to fall back to the ITU-T recommendation V.34 mode from the communication unit 1 and performing recovery, the fallback may be performed after the end of the training in phase 3. In the procedure of the transmission signals CP and CP ′ of the communication unit of ITU-T, if it is determined that the connection cannot be established by the ITU-T recommendation V.90 due to deterioration of the line status, the first communication unit forcibly Fallback may be performed at the time of CP signal transmission in phase 4 by creating INFO data that falls back to .34 mode and performing recovery.

  Another embodiment of the present invention is a data communication method for performing data communication between communication terminal devices, wherein the first communication unit transmits a procedure signal compliant with ITU-T recommendation V.8, A JM signal transmitted from the called side is received, an operation common mode is selected based on the detection result of the first receiving means, a recommended type to be connected is indicated, and the second communication unit is an ITU-T recommendation A procedure signal compliant with V.90 is transmitted, a procedure signal transmitted from the called party is received, and the control means uses the detection result of ITU-T recommendation V.8 as a common mode as ITU-T recommendation V.90. Is selected, and it is determined whether or not the connection can be made according to ITU-T recommendation V.90 selected in accordance with the signal degradation state of the connection line measured in phase 2, and if it is determined that connection is not possible, phase 3 or phase 4 Switch to the ITU-T recommendation V.34 signal procedure earlier than the recovery procedure defined in the ITU-T recommendation. In this method, a procedure signal conforming to V.34 is transmitted and a procedure signal transmitted from the called party is received.

  Here, when the control means determines that the line condition deteriorates and connection cannot be made according to ITU-T recommendation V.90 when the procedure of the transmission signal TRN of the first communication unit is completed, By creating INFO data that is forced to fall back to the ITU-T recommendation V.34 mode from the communication unit 1 and performing recovery, the fallback may be performed after the end of the training in phase 3. In the procedure of the transmission signals CP and CP ′ of the communication unit of ITU-T, if it is determined that the connection cannot be established by the ITU-T recommendation V.90 due to deterioration of the line status, the first communication unit forcibly Fallback may be performed at the time of CP signal transmission in phase 4 by creating INFO data that falls back to .34 mode and performing recovery.

That is, according to the present embodiment, the fallback is performed after the training in the phase 3 (3-a portion in FIG. 3 / FIG. 5) is completed or the CP signal is transmitted in the phase 4 (4-a portion in FIG. 4 / FIG. 6). ) To solve the above problem.
For example, in the above two methods, if the line degradation factor measured in phase 2 existing on the actual line cannot be fallback to ITU-T recommendation V.34 (using INFO information), V.90 modulation phase 3 It is a method to move to. In this case, as a result of operating an equalizer, an echo canceller, and the like in the training section in phase 3, the V.34 modulation is forcibly fallback before reaching the data transmission phase.
Further, in the present embodiment, the comparison to be performed in the phase 3 is forcibly fallback to the V.34 modulation according to the value of the equalizer in the same manner while the CP signal of the phase 4 is received. Is.

  By using the above method, in the phase 3 and 4 of ITU-T recommendation V.90, when performing a forced fallback from ITU-T recommendation V.90 to ITU-T recommendation V.34, it is connected with an analog line. The present invention provides a communication terminal device and a communication method capable of shortening the time required for connection as a modem system and obtaining a stable connection without disconnection although the modulation mode is changed and the communication rate is lowered.

  The embodiment of the communication terminal apparatus of the present invention reduces the number of INFO information exchanges when the line condition is poor despite the common operation mode selected in ITU-T recommendation V.8, and performs line connection stably. It is possible to reduce the time required for INFO information exchange and probing defined in ITU-T Recommendation V.34 and ITU-T Recommendation V.90, and to reduce the time required for handshaking between modems. become able to.

[Example 1: Method for fallback after completion of training in phase 3 (3-a portion in FIG. 3 / FIG. 5)]
When the procedure of the analog modem (Analog Modem) transmission signal TRN in the figure below is completed, the status of the equalizer and echo canceller on the actual line to be connected is known. Compare the value of the equalizer error at this time with the threshold value, and if it is worse than the fixed value, create INFO data that forcibly falls back to the V.34 mode from the analog modem and perform recovery. (Long arrow pointing to the left in the figure). As a result, the following procedure (J signal transmission in phase 3 → S signal transmission → S ^ signal transmission → SCR signal transmission → S signal transmission → S ^ signal transmission, phase 4 SCR signal transmission → CP signal transmission → CP ′ signal Transmission → E signal transmission → B1 signal transmission: without stepping on the right arrow in the figure, it is possible to shift from phase 2 to V.34 modulation mode and connect in a short time (about 10 seconds) It becomes possible.

[Embodiment 2: Fallback method at the time of CP signal transmission in phase 4 (part 4-a in FIG. 4 / FIG. 6)]
During the procedure of analog modem transmission signals CP and CP 'in the figure below, the state of the equalizer on the actual line to be connected is updated. At this time, the value of the equalizer error and the threshold value similar to the above are updated. If it is worse than a certain value, recovery is performed by creating INFO data that forcibly falls back to V.34 mode from an analog modem. As a result, without going through the following procedure (CP signal transmission in phase 4 → CP 'signal transmission → E signal transmission → B1 signal transmission), the phase shifts to V.34 modulation mode in a stable and short time. It becomes possible to connect.

  The present invention can be applied to a modem device, a communication terminal device including a host, and the like.

It is explanatory drawing which shows ITU-T recommendation V and 90 phase 1 (ITU-T recommendation V.8). It is explanatory drawing of ITU-T recommendation V.90 phase 2. FIG. It is explanatory drawing of ITU-T recommendation V.90 phase 3. FIG. It is explanatory drawing of ITU-T recommendation V.90 phase 4. FIG. FIG. 4 is an enlarged view of a portion 3-a in FIG. 3, and is an explanatory diagram of a method for performing a fallback after the end of training in phase 3. FIG. 5 is an enlarged view of a 4-a part of FIG. 4, and is an explanatory diagram of a method of performing a fallback when transmitting a CP signal in phase 4.

Explanation of symbols

ANSam signal Deformation response tone signal CM signal Calling menu signal CJ signal CM terminator signal JM signal Common menu signal TRN signal Training signal

Claims (6)

In a communication terminal device having a function of performing data communication,
The first transmission means for transmitting a procedure signal compliant with ITU-T recommendation V.8, the first reception means for receiving a JM signal transmitted from the called side, and the detection results of the first reception means A first communication unit having an identification detection unit that selects an operation common mode based on the recommended type to be connected;
A second communication unit having a second transmission means for transmitting a procedure signal compliant with ITU-T recommendation V.90, and a second reception means for receiving a procedure signal transmitted from the called side;
The ITU-T recommendation V.90 is selected as the common mode in the detection result of the ITU-T recommendation V.8, and is selected in accordance with the signal degradation state of the connection line measured in phase 2. A control means for switching from the phase 3 or phase 4 to the ITU-T recommendation V.34 signal procedure earlier than the recovery procedure stipulated in the ITU-T recommendation when it is determined that the connection cannot be made at 90;
And a third communication unit having a third transmission unit for transmitting a procedure signal compliant with ITU-T recommendation V.34 and a third reception unit for receiving a procedure signal transmitted from the called side. A communication terminal device.   When the control means determines that the line condition has deteriorated and connection cannot be made according to the ITU-T recommendation V.90 when the procedure of the transmission signal TRN of the first communication unit is completed, the first communication 2. The information processing apparatus according to claim 1, wherein the INFO data forcibly falls back to the ITU-T recommendation V.34 mode is generated by the recovery section and the recovery is performed so that the fallback is performed after the end of the phase 3 training. Communication terminal device.   When the control means determines that the connection status cannot be established according to the ITU-T recommendation V.90 during the procedure of the transmission signals CP and CP ′ of the first communication unit, the first communication is performed. The INFO data that is forcibly fallback to the ITU-T recommendation V.34 mode is created from the part and recovery is performed, so that the fallback is performed at the time of CP signal transmission in phase 4. The communication terminal device described. In a data communication method for performing data communication between communication terminal devices,
The first communication unit transmits a procedure signal compliant with ITU-T recommendation V.8, receives a JM signal transmitted from the called side, and operates in common based on the detection result of the first receiving means. Select the mode, indicate the recommendation type to be connected,
The second communication unit transmits a procedure signal compliant with ITU-T recommendation V.90, receives a procedure signal transmitted from the called side,
The control means selects the ITU-T recommendation V.90 as the common mode based on the detection result of the ITU-T recommendation V.8, and selects the ITU-T selected in accordance with the signal degradation status of the connection line measured in phase 2. If it is determined whether or not connection is possible according to T recommendation V.90, and if it is determined that connection is not possible, the signal procedure of ITU-T recommendation V.34 is earlier than the recovery procedure defined in ITU-T recommendation from phase 3 or phase 4. Switch to
A third communication unit transmits a procedure signal compliant with ITU-T recommendation V.34, and receives a procedure signal transmitted from the called side.   When the control means determines that the line condition has deteriorated and connection cannot be made according to the ITU-T recommendation V.90 when the procedure of the transmission signal TRN of the first communication unit is completed, the first communication 5. The BACK data is forced to fall back to the ITU-T recommendation V.34 mode by creating INFO data for recovery by executing recovery after completing phase 3 training. Data communication method.   When the control means determines that the connection status cannot be established according to the ITU-T recommendation V.90 during the procedure of the transmission signals CP and CP ′ of the first communication unit, the first communication is performed. 5. The INFO data that is forcibly fallback to the ITU-T recommendation V.34 mode is generated from the part and recovery is performed, so that fallback is performed at the time of CP signal transmission in phase 4. The data communication method described.

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