JPH0132697B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a terminal mode switching signal system for a digital telephone. In recent years, control signals (dial signals, ringing signals, etc. sent and received between the telephone and the exchange when making and receiving calls)
The usefulness of digital telephone systems, which transmit and receive information such as voice and data in the form of digital signals through exchanges, has been recognized. (2) The quality of calls remains constant regardless of transmission loss, and (3) high-speed data communication between telephones becomes possible. It is in becoming etc. However, conventional digital telephone systems of this type have had difficulty in switching from call mode to data communication mode. In other words, if a specific code is used to switch from call mode to data communication mode, if there happens to be a part similar to this code in the voice waveform during a call, a malfunction will occur. guard time, resulting in a long switching time. In addition, when performing simultaneous voice and data communication by deleting a part of the digitized voice code and inserting a data communication signal into the deleted part, it is possible to switch from simultaneous communication mode to call mode. Alternatively, when switching to data communication mode, the probability of occurrence of a signal similar to a specific code may become even greater, and a longer guard time is required. The present invention has been made in view of such conventional drawbacks, and it transmits and receives a specific code signal that alternates at a predetermined frame period during a call or communication, and changes the usage mode of the other party's phone and the usage mode of the own phone. This provides a terminal mode switching signal system configured to switch the terminal mode. The details of the present invention will be explained below using the drawings. FIG. 1 is a block diagram of the configuration of a digital telephone used in an embodiment of the present invention, in which 1 is a transmitter, 2 is a receiver, 3 is a low-speed data transmitter, 4 is a low-speed data receiver, and 5 is a High-speed data transmitter, 6 is a high-speed data receiver, 7 is a usage mode switching control unit, 8
9 is a first transmission signal switching section; 9 is a reception signal switching section;
10 is an encoder, 11 is a second transmission signal switching unit, 1
2 is a line interface section, 13 is a subscriber line,
14 is a decoder, 15 is a usage mode switching operation unit, 1
6 is a usage mode display section. The digital telephone of this embodiment has the following three usage modes. The first usage mode is a normal call mode, in which the transmitter 1 is used in the transmission system, and the receiver 2 is used in the reception system. The second usage mode is a simultaneous communication mode for telephone calls and low-speed data, in which the transmitter 1 and low-speed data transmitter 3 are used in the transmission system, and the receiver 2 and the low-speed data receiver 4 are used in the reception system. The third usage mode is a data communication mode, in which the high-speed data transmitter 5 is used in the transmission system, and the high-speed data receiver 6 is used in the reception system. These three usage modes are switched by the first transmission signal switching unit 8 and the reception signal switching unit 9 based on a command from the usage mode switching control unit 7. In the first usage mode, an analog audio signal from the transmitter 1 is converted into a digital signal by the encoder 10, and the signal is transferred to the first transmission signal switching section 8, the second transmission signal switching section 11, and the line interface. Part 12
The signal is sent to the subscriber line 13 via the subscriber line 13. At this time, the first transmission signal switching section 8 validates only the signal from the handset 1 based on the command from the usage mode switching control section 7, and disables the signals from the low-speed data transmitter 3 and the high-speed data transmitter 5. shall be. On the other hand, the received signal from the subscriber line 13 is transmitted to the line interface section 12.
The received signal is transmitted to the received signal switching section 9 via. The received signal switching unit 9 transmits the received signal only to the decoder 14 based on the command from the usage mode switching control unit 7, and transmits the received signal to the low-speed data receiver 4 and the high-speed data receiver 6.
The signal to is invalidated. The signal transmitted to the decoder 14 is converted into an analog signal and transmitted to the handset 2. In the second usage mode, based on the command from the usage mode switching control unit 7, the first transmission signal switching unit 8
, only the signal from the handset 1 and the signal from the low-speed data transmitter 3 are valid, and the high-speed data transmitter 5
The signal from is invalidated. The transmission signal and the low-speed data transmission signal are sent to the second transmission signal switching section 11, the line interface section 12, and the subscriber line 13. On the other hand, the reception signal and low-speed data reception signal on the subscriber line 13 are transmitted to the telephone receiver 2 and the low-speed data receiver 4 via the line interface section 12 and reception switching section 9, respectively. In the third usage mode, based on the command from the usage mode switching control unit 7, the first transmission signal switching unit 8
At this point, only the signal from the high-speed data transmitter 5 becomes valid, and this signal is further transmitted onto the subscriber line 13 via the second transmission signal switching section 11 and the line interface section 12. On the other hand, the high-speed data reception signal on the subscriber line 13 is received by the high-speed data receiver 6 via the line interface section 12 and the reception signal switching section 9 which operates based on commands from the use mode switching control section 7. FIG. 2 shows an example of the frame structure of a digital signal on the subscriber line 13 of FIG. 1. In FIG. 2, section T1 indicates one frame, section T2 indicates a transmission section, and section T3 indicates a reception section, and the times are 2 ms, 1 ms, and 1 ms in the same order, and 336 bits, 168 bits, and 168 bits, respectively in the same order.
It consists of Therefore, the transmission speed is 168kbps. In the transmission period T2, TF is a transmission frame synchronization signal, TS1 and TS2 are control signals from the telephone to the exchange, TW1 to TW16 are transmission signals from the own telephone to the other party's telephone, and TG1 and TG2 are guard times between transmission and reception. . In the reception period T3, RF receives the reception frame synchronization signal, RS1 and
RS2 is a control signal from the exchange to the telephone, RW1
~RW16 is a received signal from the other party's telephone to the own telephone, and RG1 and RG2 are guard times for reception and transmission. Each of TF to RG2 described above is composed of 8 bits. Figure 3 shows each word TW1 to TW in Figure 2.
16 and any one of RW1 to RW16. In FIG. 3, A is an example of the structure of a transmission or reception word in the first use mode, in which the voice signal for a telephone conversation occupies all 8 bits, and the transmission speed is 16 x 8 bits/bit for both transmission and reception. 2ms = 64kbps. Similarly, B is an example of the structure of the transmitted or received word in the second usage mode,
The 8 bits that make up one word are the audio signal for phone calls.
The transmission speed is 16 x 7 bits/2 ms = 56 kbps for the audio signal and 16 x 1 bit/2 ms = 8 kbps for the low speed data signal for both transmission and reception. Similarly, C is an example of the configuration of a transmission or reception word in the third usage mode mentioned above, in which all 8 bits are dedicated to high-speed data signals, and the transmission speed is 16 x 8 bits / 2 ms = 64 kbps for both transmission and reception. There is. Similarly, D exemplifies a switching signal for switching the usage mode, and all 8 bits are used exclusively by the switching signal. An example of an intra-frame arrangement of switching signals is one in which the same switching signal continues throughout all of the first to 16th words. Another example of the in-frame arrangement of the switching signal is such that the bit configurations are inverted between the first, third, . . . 15th odd words and the second, fourth, . . . 16th even words. The bit configuration alternates between adjacent words. Still another example of the intra-frame arrangement of switching signals is that the first eight words of the first to eighth words and the ninth
The bit configuration is inverted between the last eight words of the word to the 16th word. In any of the above cases, the arrangement of switching signals within one frame is alternated at a predetermined frame period (every one or more frames) so as not to be mistakenly recognized as an audio signal or a data signal. That is, the words corresponding between frames are alternated every one or more frames. In the above, when all 8-bit switching signals are alternated at a predetermined frame period, for example, 01111110
In the above description, a method in which only a part of the 8-bit switching signal is alternated, such as 01111110 to 01110001, in which only the lower 4 bits are alternated, may be used. An example of this
Table 1 shows the case where the frames are alternated at a frame period.

[Table] Since switching signals that alternate at a predetermined frame period are used in this way, the probability of being mistakenly recognized as an audio signal or a data signal is extremely small, and the duration of the switching signal on the order of 10 ms is sufficient. FIG. 4 is a block diagram showing an example of a more detailed configuration of the usage mode switching control section 7 shown in FIG.
9 is a mode switching signal receiving section, and 20 is a control section. The mode switching signal generation unit 17 detects the type of specified mode pressed by the use mode switching operation unit 15, generates a mode switching signal as shown in Table 1 for a predetermined period of time, and also A signal representing the type (mode signal) is sent to the control/storage unit 18. The control/storage unit 18 detects that the use mode switching operation unit 15 is pressed, and the second
The transmission signal switching unit 11 is the mode switching signal generation unit 1
The switching section 11 is controlled to pass the mode switching signal sent from the first transmission signal switching section 7 and invalidate the signal from the first transmission signal switching section 8, and further stores the mode signal from the generation section 17. The mode switching signal receiving section 19 receives the mode switching signal sent from the partner terminal via the line interface section 12, and transmits the designated mode signal to the control section 20. The control unit 20 that received this
performs switching control of the first transmission signal switching unit 8 and reception signal switching unit 9 and drives the usage mode display unit 16, and also controls the mode switching signal generation unit 17 and the control/storage unit 18 to change the usage mode described above. Similar to when the switching operation section 15 is pressed, a signal for driving the generation section 17 and the control/storage section 18 is sent out.
At this time, the control/storage unit 18 compares the pre-stored mode signal with the mode signal sent from the mode switching signal receiving unit 19, and controls the second transmission signal switching unit 11 only when the two are different. At the same time as sending out the signal, the newly sent mode signal is stored. As explained in detail above, the present invention is configured to switch the use mode of the other party's telephone and the own telephone by sending and receiving a switching signal that alternates at a predetermined frame period during a call or data communication. The probability that a signal will be mistakenly recognized as a voice signal or a data signal is extremely small, and the duration of the switching signal is sufficient to be around 10 msec, making extremely highly efficient voice/data mixed communication possible.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the configuration of a telephone used in an embodiment of the present invention, FIG. 2 is a frame configuration diagram of a digital signal on the subscriber line 13 of FIG.
FIG. 3 is a diagram showing an example of the configuration of an arbitrary word in FIG. 2, and FIG. 4 is a block diagram showing an example of a more detailed configuration of the usage mode switching control section 7 shown in FIG. 1... Transmitter, 2... Handset, 3... Low-speed data transmitter, 4... Low-speed data receiver, 5... High-speed data transmitter, 6... High-speed data receiver, 7...
Usage mode switching control unit, 8...first transmission signal switching unit, 9...reception signal switching unit, 10...encoder,
11...Second transmission signal switching unit, 12...Line interface unit, 13...Subscriber line, 14...
Decoder, 15... Use mode switching operation section, 16...
... Usage mode display section, 17... Mode switching signal generation section, 18... Control/storage section, 19... Mode switching signal receiving section, 20... Control section.

Claims (1)

[Claims] 1. During a call or communication between telephones in a digital telephone system in which voice, data, and control signals are transmitted and received as framed digital signals via an exchange, transmission is performed at a predetermined frame period instead of voice or data frames when switching modes of use. A terminal mode switching signal system for a digital telephone characterized in that the mode is switched by transmitting and receiving a use mode switching signal of an alternating specific code.