JP2012222690A - Transmission system and transmission band control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To expand a packet signal transmission band while no voice signals are being transmitted, thereby making it possible to use a transmission band efficiently.SOLUTION: A transmission system includes: a voice input processing unit which accepts as its input a voice signal and a signaling signal; a packet input processing unit which accepts as its input a packet signal; a transmission band control unit which, when there is no signaling signal, allocates a packet signal to a voice signal time slot; a multiplexing unit which multiplexes a voice signal having a signaling signal multiplexed thereinto and a packet signal together after allocating them a time slot; a separation unit which, upon receiving the multiplexed signal, separates it into a voice signal and a signaling signal and a packet signal; a reception band control unit which, in cases when the signaling signal has no voice, separates a signal received in the voice signal time slot as a packet signal therefrom; a voice output processing unit which outputs separated voice and signaling signals; and a packet output processing unit which outputs a separated packet signal.

Description

  The present invention relates to a technique for efficiently controlling a transmission band in a transmission system that multiplexes and transmits a voice signal and a signaling signal and a packet signal accompanying the voice signal.

  In general, a transmission system that multiplexes and transmits a packet signal for data transmission using Ethernet (registered trademark) or the like and a voice signal that is PCM-encoded for a voice line is known. Also, for voice signals for voice lines, for example, it is necessary to send and receive signaling signals indicating the off-hook / on-hook state of the handset of the telephone, and a technology to multiplex the signaling signals into voice signals using the bit-steal method has been developed. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 06-204967

  However, since the conventional transmission system uses a fixed band preset for each signal, the band is occupied for the audio signal even when the audio signal is not transmitted, and the transmission band is efficiently used. There was a problem that was not planned.

  In view of the above problems, an object of the present invention is to provide a transmission system and a transmission band control method capable of efficiently using a transmission band by expanding a transmission band of a packet signal when an audio signal is not transmitted. Is to provide.

  The transmission system according to the present invention is a transmission system that multiplexes and transmits a voice signal, a signaling signal accompanying the voice signal, and a packet signal in a predetermined time slot between the transmission apparatuses. A voice input processing unit that inputs a voice signal and the signaling signal; a packet input processing unit that inputs the packet signal; and a time for the voice signal when the presence or absence of the signaling signal is detected and the signaling signal is absent. A transmission band control unit that performs band control for allocating the packet signal to a slot, and a signal in which the voice signal, the signaling signal, and the packet signal are multiplexed by allocating time slots according to band control of the transmission band control unit A multiplexing unit for transmitting the signal to the transmission line and a signal multiplexed from the transmission line. A separation unit that separates the voice signal from the signaling signal and the packet signal; and a band control that separates a signal of a time slot for the voice signal when there is no signaling signal as the packet signal. A reception band control unit for performing the above, a voice output processing unit for outputting the voice signal and the signaling signal separated by the separation unit, and a packet output processing unit for outputting the packet signal separated by the separation unit to the outside It is characterized by having.

  In particular, the multiplexing unit performs transmission band control on a signal obtained by multiplexing the signaling signal by the bit steal method on the audio signal input from the audio input processing unit and the packet signal input from the packet signal input processing unit. A signal multiplexed by allocating time slots according to the band control of each part is transmitted to the transmission line.

  Alternatively, the multiplexing unit outputs a signal obtained by multiplexing the signaling signal to the audio signal input from the audio input processing unit by a signaling multiframe method and the packet signal input from the packet signal input processing unit. A multiplexed signal is assigned to a time slot according to the bandwidth control of the control unit, and the multiplexed signal is transmitted to the transmission line.

  Further, the transmission band control unit detects that the voice input processing unit is not installed or is turned off based on the presence or absence of the signaling signal output from the voice input processing unit, and allocates the packet signal to the time slot of the voice signal. It is characterized by that.

  In particular, the multiplexing unit multiplexes corresponding to a primary group interface of 1.544 Mbit / s digital hierarchy.

  Alternatively, the multiplexing unit multiplexes corresponding to a 6.212 Mbit / s digital hierarchy secondary group interface.

  The signal obtained by multiplexing the signaling signal by the signaling multi-frame method includes error correction function data.

  The transmission band control method according to the present invention is a transmission band control used in a transmission system that multiplexes and transmits a voice signal, a signaling signal accompanying the voice signal, and a packet signal in a predetermined time slot between transmission apparatuses. In the method, the presence / absence of the signaling signal accompanying the audio signal is detected, and when the signaling signal does not exist, band control is performed to allocate the packet signal to a time slot for the audio signal, and the audio signal and the signaling The signal and the packet signal are allotted to the time slot and the multiplexed signal is transmitted to the transmission line, the multiplexed signal is received from the transmission line, and is separated into the voice signal, the signaling signal, and the packet signal. The signaling signal is detected by detecting the presence or absence of the signaling signal. It performs band control for separating signals of the time slot for the audio signal in the absence of a said packet signal, and outputs the audio signal and signaling signal and a packet signal after separation to the outside.

  In particular, the signaling signal is multiplexed with the audio signal by a bit steal method.

  Alternatively, the signaling signal is multiplexed with the audio signal by a signaling multiframe method.

  The transmission system and the transmission band control method according to the present invention detect the presence or absence of a signaling signal accompanying a voice signal without using a complicated circuit such as a silence detection circuit for the voice signal, and the voice signal is not transmitted. Sometimes the transmission band can be used efficiently by expanding the transmission band of the packet signal.

It is a figure which shows the structural example of the transmission system 100 which concerns on 1st Embodiment. It is a figure which shows the example of a band division of the transmission system 100 which concerns on 1st Embodiment. It is a figure which shows the frame structure of a signaling bit steal system. It is a timing chart of transmission band control of the transmission system 100 concerning a 1st embodiment. It is a figure which shows the structural example of the transmission system 200 which concerns on 2nd Embodiment. It is a figure which shows the frame structure of a signaling multi-frame system. It is a figure which shows the example of the signaling multi-frame of the transmission system 200 which concerns on 2nd Embodiment. It is a timing chart of transmission band control of transmission system 200 concerning a 2nd embodiment. It is a figure which shows the structural example of the conventional transmission system 900. FIG. It is a figure which shows the example of a band division | segmentation of the conventional transmission system 900. FIG.

  Hereinafter, embodiments of the “transmission system and transmission band control method” according to the present invention will be described in detail. In each of the following embodiments, a voice signal PCM-encoded for a voice line, a signaling signal accompanying the voice signal, and a packet signal for data transmission using Ethernet (registered trademark), etc. are multiplexed in a time slot and transmitted. The transmission system 100 will be described.

  In the transmission system 100, a voice signal for a voice line is accompanied by a signaling signal indicating a state such as off-hook / on-hook of a telephone handset, and it is necessary to transmit and receive the voice signal and the signaling signal together. The signaling signal is a signal for informing the telephone on the called side that it is in an off-hook state when the handset of the calling telephone is off-hooked, for example.

  In general, a primary group interface (1.544 Mbit / s digital hierarchy interface) is known as a standard for multiplexing a packet signal for data transmission via Ethernet (registered trademark) and the like and a PCM-encoded voice signal. The signaling signal is multiplexed and transmitted by a bit steal method or a multi-frame method.

Here, before describing each embodiment, an example of a general transmission system 900 in a case where the transmission band of a voice signal and a packet signal is fixed will be described so that the characteristics of the transmission system 100 according to the present invention can be easily understood. .
[Example of fixing the transmission band of voice signal and packet signal]
FIG. 9 is a diagram illustrating a configuration example of the transmission system 900. 9, the transmission system 900 transmits data such as an audio input signal (1-1), a signaling signal (1-2) accompanying the audio input signal (1-1), and Ethernet (registered trademark). A transmission apparatus 901 that receives and multiplexes the packet input signal (1-3), receives the multiplexed signal via the transmission path (1-7), and receives an audio output signal (1-11) The transmission device 902 separates and outputs the signaling output signal (1-12) and the packet output signal (1-13). FIG. 9 shows an example of transmission from the transmission apparatus 901 to the transmission apparatus 902, but the transmission apparatus 901 has the same reception side function as the transmission apparatus 902, and the transmission apparatus 902 is connected to the transmission apparatus 901. Since the transmission side 902 has the same function on the transmission side, in reality, a voice signal, a signaling signal, and a packet signal are multiplexed and transmitted from the transmission apparatus 902 to the transmission apparatus 901, and each signal is transmitted between the transmission apparatus 901 and the transmission apparatus 902. Are sent and received. In each of the following drawings, only one-way communication will be described, and description of reverse communication will be omitted.
[Sender]
In FIG. 9, the transmission apparatus 901 on the transmission side includes a voice input processing unit (1-4), a packet input processing unit (1-5), and a multiplexing unit (1-6).

  The voice input processing unit (1-4) is connected to a telephone or the like, and is a voice input signal (1-1) input from the handset, and a signaling input signal (1-2) indicating, for example, on-hook / off-hook of the telephone handset. Enter. The voice input signal (1-1) is PCM-encoded in the voice input processing section (1-4) and output to the multiplexing section (1-6) as a digital signal (64 Kbps). The signaling input signal (1-2) is synchronized with the presence / absence of signaling control in the voice input processing unit (1-4) and then output to the multiplexing unit (1-6). .

  The packet input processing unit (1-5) takes the packet input signal (1-3) into the internal frame buffer and synchronizes it, and then outputs it as a digital signal to the multiplexing unit (1-6).

  The multiplexing unit (1-6) is configured to set a predetermined digital signal output from the voice input processing unit (1-4) and a digital signal output from the packet input processing unit (1-5). The signals are multiplexed into time slots TS (TS1 to TSn in the example of FIG. 9) of signal transmission channels divided by time intervals, and transmitted to the transmission path (1-7).

Each signaling input signal (1-2) is bit-stealed into a PCM-encoded audio signal, or a plurality of signaling input signals (1-2) are multiplexed into a single TS and multiplexed. (1-7). Then, the multiplexed signal transmitted at the preset transmission rate is transmitted to the transmission apparatus 902 on the reception side via the transmission path (1-7).
[Receiver]
The transmission apparatus 902 on the reception side includes a separation unit (1-8), an audio output processing unit (1-9), and a packet output processing unit (1-10).

  The separation unit (1-8) separates the signal received from the transmission line (1-7) for each time slot (TS1 to TSn) of the signal transmission channel divided at a predetermined time interval, Each digital signal is output to the voice output processing unit (1-9) and the packet output processing unit (1-10). In addition, a signaling signal multiplexed on the audio signal by the bit-steal method and a plurality of signaling signals multiplexed by the multi-frame method are also separated into the respective signaling signals and the audio output processing unit (1-9) Is output.

  The voice output processing unit (1-9) PCM-decodes the digital signal output from the separation unit (1-8) and outputs it as a voice output signal (1-11) to a telephone handset connected to the outside. The signaling output signal (1-12) is output to an external telephone corresponding to the voice output signal (1-11) by controlling the presence / absence of signaling.

The packet output processing unit (1-10) temporarily takes the digital signal output from the separation unit (1-8) into the frame buffer, and then, for example, as a packet output signal (1-13) such as Ethernet (registered trademark). Output to an external device (router, personal computer, etc.).
[Transmission bandwidth]
In the transmission system 900, for example, as shown in FIG. 10, n time slots TS (TS1 to TSn) are allocated to voice signals and packet signals, and a multiplexing unit (1-6) and a demultiplexing unit (1-8) are allocated. ). In the example of FIG. 10, time slots from time slots TS1 to TS (n-1) are allocated for voice signals, and time slot TSn is allocated for packet signals.

  As described above, in the conventional transmission system 900, transmission band allocation is fixed for audio signals and packet signals, and packet signals such as Ethernet (registered trademark) are used regardless of whether audio signals are used or not. However, there is a problem that transmission is performed only in a preset time slot and the transmission band is not effectively used.

(First embodiment)
Thus, in the transmission system 100 according to the present embodiment, when the audio signal is not transmitted, the transmission band can be effectively used by using the audio signal band as the packet signal band.
[Transmission system 100]
The transmission system 100 according to the present embodiment multiplexes the signaling signal by the bit steal method, determines that there is no voice call when the signaling control is OFF, and allocates the time slot for the voice signal at that time for the packet signal. By transmitting, effective use of the transmission band can be easily achieved.

FIG. 1 is a diagram illustrating a configuration example of a transmission system 100 according to the first embodiment. In FIG. 1, a transmission system 100 transmits data such as an audio input signal (2-2), a signaling signal (2-1) accompanying the audio input signal (2-2), and Ethernet (registered trademark). A transmission apparatus 101 that receives and multiplexes a packet input signal (2-3), a signal that is multiplexed via a transmission line (2-13), and an audio output signal (2-24) The transmission apparatus 102 is configured to separate and output the signaling output signal (2-23) and the packet output signal (2-25). Note that FIG. 1 shows an example of transmission from the transmission apparatus 101 to the transmission apparatus 102, but the transmission apparatus 101 has the same reception side function as the transmission apparatus 102, and the transmission apparatus 102 is the same as the transmission apparatus 101. Since the transmission side 102 has the same function on the transmission side, audio signals, signaling signals, packet signals, and the like are actually multiplexed and transmitted from the transmission device 102 to the transmission device 101 in time slots. Each signal is transmitted and received between them. In each of the following drawings, only one-way communication will be described, and description of reverse communication will be omitted.
[Sender]
In FIG. 1, the transmission apparatus 101 on the transmission side includes a voice input processing unit (2-4), a packet input processing unit (2-5), a transmission bandwidth control unit (2-6), and a multiplexing unit (2- 8). There are a plurality of voice input processing units (2-4) (m in the example of FIG. 1; m is an integer). In the figure, (number) is added, and when it is a common matter, it is expressed as a voice input processing unit (2-4) without adding (number). The same applies to a plurality of blocks and signals. For example, since there are a plurality of audio input signals (2-2), they are represented as audio input signals (2-2) -m only when individually indicated.

  In FIG. 1, a voice input processing unit (2-4) is connected to a telephone or the like, and receives a voice input signal (2-2) input from a handset and a signaling input signal (2-1) indicating on-hook / off-hook of the handset. ). The audio input signal (2-2) is PCM encoded by the PCM encoding unit (2-4b) of the audio input processing unit (2-4), and is multiplexed as a digital signal (64 Kbps) (2-8). Is output. Further, the signaling control signal (2-1) is synchronized with the signaling control signal synchronized with the presence / absence of signaling control determined by the signaling control detection unit (2-4a) of the voice input processing unit (2-4). A1 to Am are output to the transmission band control unit (2-6) and the multiplexing unit (2-8).

  The packet input processing unit (2-5) takes the packet input signal (2-3) into the internal frame buffer unit (2-5a) and synchronizes it, and then sends it to the multiplexing unit (2-8) as a digital signal. Is output.

  The multiplexing unit (2-8) has a predetermined time interval between the signal output from the voice input processing unit (2-4) and the signal output from the packet input processing unit (2-5). Are multiplexed into the time slot TS of the signal transmission channel divided by (1) and transmitted to the transmission line (2-13). Note that the multiplexing unit (2-8), when the multiplexing timing signal (2-7) is not output from the transmission band control unit (2-6) (when there is a signaling control signal), the PCM transmission signal (2-10) ) Is multiplexed into a time slot assigned in advance by the PCM encoded signal multiplexing timing signal (2-9). Conversely, when the multiplex timing signal (2-7) is output from the transmission band control unit (2-6) (when there is no signaling control signal), the time slot of the corresponding PCM transmission signal (2-10) A packet multiplexing timing signal (2-11) for carrying the transmission packet signal (2-12) is output to multiplex the transmission packet signal (2-12).

  The transmission band control unit (2-6) collects the signaling control signals A1 to Am output from the respective voice input processing units (2-4), and if each signal is in a state without signaling control, the corresponding time slot. A multiplexing timing signal (2-7) for multiplexing the transmission packet signal (2-12) to the TS is output to control the bandwidth of the multiplexing unit (2-8).

In the transmission system 100 according to the present embodiment, each signaling input signal (2-1) is multiplexed on the digital signal of the voice input signal (2-2) encoded by the PCM by the bit steal method, and the transmission path (2 -13). Then, the multiplexed signal transmitted at the preset transmission rate is transmitted to the transmission apparatus 102 on the reception side via the transmission path (2-13).
[Receiver]
The transmission apparatus 102 on the reception side includes a separation unit (2-14), a reception band control unit (2-15), an audio output processing unit (2-21), and a packet output processing unit (2-22). Composed.

  The separation unit (2-14) separates the signal received from the transmission path (2-13) for each time slot (TS1 to TSn), and outputs each signal to the voice output processing unit (2-21) or the packet output. The data is output to the processing unit (2-22). Further, the signaling control signals A1 to Am are extracted and output to the audio output processing unit (2-21) and the reception band control unit (2-15).

  If the signaling control signals A1 to Am output from the separation unit (2-14) are in a state where there is no signaling control, the reception band control unit (2-15) receives the received packet signal from the corresponding voice time slot TS. A separation timing signal (2-16) for separating (2-20) is output to control the bandwidth of the separation unit (2-14), and the received packet signal (2-20) and the packet separation timing signal (2 -19) to the packet output processing unit (2-22). In this case, the PCM reception signal (2-18) together with the PCM reception signal separation timing signal (2-17) is fixed to ALL “1” and output to the audio output processing unit (2-21) to reproduce the silent state. .

  The audio output processing unit (2-21) decodes the PCM signal based on the PCM reception signal separation timing signal (2-17) and the PCM reception signal (2-18), and outputs the audio output signal (2-24) to the outside. Output to the handset of the connected phone. Further, the signaling control signals A1 to Am are output to a telephone connected to the outside as a signaling output signal (2-23) corresponding to presence / absence of signaling control.

The packet output processing unit (2-22) takes the received packet signal (2-20) into the frame buffer unit (2-22a) once by the packet separation timing signal (2-19), and then outputs the packet output signal for each frame. (2-25) is output to an external device (router, personal computer, etc.).
[Transmission bandwidth]
Next, an example of transmission band control in the transmission system 100 will be described with reference to FIG. FIG. 2 is a diagram illustrating the relationship between the states of the signaling control signals A1 to Am and the signals multiplexed in the time slots TS (TS1 to TSn). In the example of FIG. 2, in the predetermined transmission band, the time slot of the audio signal is assigned from TS1 to TSm, and the time slot of the packet signal is assigned only to TSn. Here, since the time slot TSn of the packet signal is only one time slot, m = n−1 in the above example, and the last time slot TSm of the audio signal is the same as the time slot TS (n−1).

  Each of FIGS. 2A to 2C shows the packet signal when there is no signaling control signal A3 corresponding to the voice input signal (2-2) -3 multiplexed in the time slot TS3 (OFF). An example of temporary allocation as a band is shown.

  In FIG. 2A, since all of the signaling control signals A1 to Am are in an ON state (with a voice signal), the voice signal (1) to the voice signal (m) are time slots according to a predetermined band allocation. Packet signals are assigned to time slots TS (n) to TS1 to TSm, respectively.

  In FIG. 2B, since only the signaling control signal A3 is in an OFF state (no audio signal), the time slot TS3 scheduled to be used for the audio signal (3) is assigned to the packet signal. As a result, the transmission bandwidth of the packet signal can be widened by effectively using the time slot in which no audio signal is transmitted.

  In FIG. 2 (c), the signaling control signal A3 returns from OFF to ON, and the signaling control signals A1 to Am are all in the ON state (the state with the audio signal) as in FIG. 2 (a). The time slot TS3 used for the packet signal is returned to the original voice signal (3). Voice signals (1) to (m) are assigned to time slots TS1 to TSm, and packet signals are assigned to time slots TS (n).

In this way, whether or not a voice signal is transmitted is detected based on the presence or absence (ON / OFF) of a signaling control signal, and when a voice signal is not transmitted, a packet signal is temporarily assigned to the time slot. Thus, it is possible to effectively use the transmission band and to widen the transmission band of the packet signal.
[Bit-steel frame configuration]
Here, a frame structure in the case of multiplexing a packet signal such as Ethernet (registered trademark) and a voice signal obtained by PCM encoding voice by a primary group interface (1.544 Mbit / s digital hierarchy interface), and a bit steal method A signaling signal multiplexing method will be described with reference to FIG.

  FIG. 3A is a diagram showing a multiframe composed of 12 frames called 12MF. FIG. 3B is a diagram showing the configuration of one frame, and has F bits and 24 time slots from TS1 to TS24. In addition, every six time slots are divided into HG1 to HG4.

  Further, FIG. 3C is a diagram showing the configuration of one time slot. Signaling control is performed at the 8th bit of each time slot of the sixth frame (MF6) and the twelfth frame (MF12) of FIG. 3A. The signals are multiplexed, and the audio signal encoded from the first bit to the seventh bit is multiplexed. In time slots other than MF6 and MF12, the audio signal is multiplexed on all 8 bits of each time slot.

  FIG. 3D is a diagram showing the configuration of the F bits corresponding to each of the 12 frames. The F bit indicates a game alarm bit, which is “1” at the time of alarm and “0” at the time of non-alarm. In the example of FIG. 3D, each frame of 1, 5, 6, 8, 9, and 10 indicates an alarm.

In this way, the signaling control signal is multiplexed and transmitted by the bit steal method at the primary group interface (1.544 Mbit / s digital hierarchy interface). In the example of FIG. 3, the case where the frame configuration is 12 MF has been described.
[Bit steal timing example]
Next, an example of the presence / absence detection and bandwidth control of a signaling signal by the bit steal method will be described with reference to FIG.

  FIG. 4 shows a signaling input signal (5-1), a multiplexed frame timing signal (5-2), and timings representing the timing of taking in signaling signals (MF6 and MF12) from the respective voice input processing units (2-4). A signal (5-3), a multi-frame signal (5-4) composed of 12 frames, a signaling detection signal (5-5), a signaling confirmation signal (5-6), and a voice signal time slot ( 5-7) is a timing chart showing the relationship between packet signal time slots (5-8).

  In FIG. 4, in the transmission apparatus 101 on the transmission side, the state of the signaling input signal (5-1) (control presence / absence) is detected at the timing of MF6 and MF12 (signaling detection signal (5-5)), and MF7 and MF1. The presence or absence of a signaling signal is determined at the timing (signaling determination signal (5-6)).

  For example, in the case of FIG. 4, the absence of signaling is determined at timing T1, and the assignment of the packet signal to the time slot for the audio signal is started and expanded as the time slot for the packet signal. The packet signal is multiplexed in the time slot excluding the sixth and twelfth frames where the bit stealing signaling signal is multiplexed.

  When the presence of signaling is determined again at timing T2, the time slot temporarily used for the packet signal is returned to the original time slot for the audio signal.

  In this way, whether or not a voice signal is transmitted is detected based on the presence or absence (ON / OFF) of a signaling control signal, and if a voice signal is not transmitted, a packet signal is temporarily assigned to the time slot. . As a result, it is possible to effectively use the transmission band and widen the transmission band of the packet signal.

  Note that there is a delay of time T3 (maximum of about 875 μsec (125 usec × 7)) until timing T2 at which the voice control starts when there is signaling control, but there is no practical problem because it is voice communication such as telephone call. Further, the signaling confirmation signal (5-6) is delayed by one frame with respect to the signaling detection signal (5-5). This is because the signaling signal is the last bit position of the data, so that the frame is packetized at this time. This is because it cannot be switched to a signal or switched back to an audio signal.

Moreover, even when the voice input processing unit (2-4) is not mounted or when the power is turned off, the circuit design is made so that the signaling signal is turned off, so that the voice signal is not used. In addition, since the time slot for the voice signal is automatically allocated for the packet signal, the transmission band can be effectively used.
(Second Embodiment)
Next, the transmission system 200 according to the second embodiment will be described. Similar to the first embodiment, the transmission system 200 according to the second embodiment includes not only a transmission apparatus that multiplexes with a primary group interface (1.544 Mbit / s digital hierarchy interface) but also a secondary group interface (6.312 Mbit / s). The present invention can be applied to a case where a signaling multiframe method is used in a transmission apparatus that multiplexes with (s digital hierarchy interface).
[Transmission system 200]
The transmission system 200 according to the present embodiment multiplexes the signaling signals by the multiframe method, determines that there is no voice call when the signaling control is OFF, and sets the time slot for the voice signal at that time as the time slot for the packet signal. By allocating to and transmitting, the transmission band can be effectively utilized easily.

FIG. 5 is a diagram illustrating a configuration example of a transmission system 200 according to the second embodiment. In FIG. 5, the transmission system 200 transmits data such as an audio input signal (6-2), a signaling signal (6-1) accompanying the audio input signal (6-2), and Ethernet (registered trademark). A transmission apparatus 201 that receives and multiplexes a packet input signal (6-3), receives a multiplexed signal via a transmission line (6-16), and outputs an audio output signal (6-32). The transmission apparatus 202 that separates and outputs the signaling signal (6-31) and the packet signal (6-33). Note that FIG. 5 shows an example of transmission from the transmission apparatus 201 to the transmission apparatus 202, but the transmission apparatus 201 has the same reception side function as the transmission apparatus 202, and the transmission apparatus 202 is the same as the transmission apparatus 201. Since the transmission side 202 has the same function on the transmission side, an audio signal, a signaling signal, a packet signal, or the like is actually transmitted from the transmission apparatus 202 to the transmission apparatus 201, and transmission / reception of each signal is performed between the transmission apparatus 201 and the transmission apparatus 202. Is called. In each of the following drawings, only one-way communication will be described, and description of reverse communication will be omitted.
[Sender]
In FIG. 5, the transmission apparatus 201 on the transmission side includes a voice input processing unit (6-4), a packet input processing unit (6-5), a transmission bandwidth control unit (6-6), and a multiplexing unit (6- 8) and a signaling multiframe generator (6-13). As in the first embodiment, there are a plurality of voice input processing units (6-4) (m: m is an integer in the example of FIG. 5), but the voice input processing units (6-4) are only shown individually. ) -1 is added to the reference numeral (number) in the figure, and if it is a common item, it is expressed as a voice input processing unit (6-4) without adding (number). . The same applies to a plurality of blocks and signals. For example, since there are a plurality of audio input signals (6-2), they are expressed as audio input signals (6-2) -m only when individually indicated.

  The voice input processing unit (6-4) is connected to a telephone or the like and inputs a voice input signal (6-2) input from the handset and a signaling input signal (6-1) indicating on-hook / off-hook of the handset. To do. The voice input signal (6-2) is PCM encoded by the PCM encoder (6-4b) of the voice input processor (6-4), and is multiplexed as a digital signal (64 Kbps) (6-8). Is output. Further, the signaling input signal (6-1) is synchronized with the signaling control signal synchronized with the presence / absence of signaling control determined by the signaling control detection unit (6-4a) of the voice input processing unit (6-4). A1 to Am are output to the transmission band control unit (6-6), the multiplexing unit (6-8), and the signaling multiframe generation unit (6-13).

  The packet input processing unit (6-5) takes the packet input signal (6-3) into the internal frame buffer unit (6-5a), synchronizes it, and then outputs it to the multiplexing unit (6-8).

  The transmission band control unit (6-6) aggregates the signaling control signals A1 to Am output from each voice input processing unit (6-4), and if each signal is in a state without signaling control, the corresponding time slot. A multiplexing timing signal (6-7) for multiplexing the transmission packet signal (6-12) to the TS is output to control the bandwidth of the multiplexing unit (6-8).

  In the transmission system 100 according to the present embodiment, each signaling input signal (6-1) is multiplexed by the multiframe method in the multiplexing unit (6-8) and transmitted to the transmission line (6-16).

  The signaling multiframe generator (6-13) generates a signaling multiframe signal by using the signaling signal as one frame, and outputs it to the multiplexer (6-8).

  In the signaling multiframe, as shown in FIG. 6, the signaling signal of each time slot is configured as one multiframe. The terminal station frame configuration in FIG. 6 includes a signaling multiframe signal using one time slot separately from actual data. In the example of FIG. 6, signaling signals of 1 to 30 channels (A1 to A30) are multiplexed in an 8 multiframe configuration.

  In FIG. 6, the 8 × 8-bit signaling multiframe signal has signaling signals A1 to A30 corresponding to 30 time slots TS of m = 30. For example, when A2 is “1”, there is signaling control, and when it is “0”, there is no signaling control. Note that 0 and 1 are synchronization bits (01111111), and X is a bit fixed to “1”.

  Here, a general signaling multiframe is configured as shown in FIG. 6, but in this embodiment, a signaling multiframe as shown in FIG. 7 is used. In FIG. 7, the same reference numerals as those in FIG. 6 denote the same components.

  In FIG. 7, the transmission side signaling multiframe generator (6-13) sets the parity calculation results from A1 to A5 on the horizontal axis to p1, and similarly, A6 to A10, A11 to A15, A16 to A20, A21 to A25. , A26 to A30 are assumed to be p2, p3, p4, p5 and p6, respectively. Further, the parity calculation results of A1, A6, A11, A16, A21, and A26 on the vertical axis are p7, and similarly, p8, p9, p10, and p11 are the parity calculation results. Note that p1 to p11 are odd parity bits.

  Then, in the signaling multi-frame receiving unit (6-22) on the receiving side, for example, when A1 causes a bit error, p1 and p7 become parity calculation errors, so that error correction can be performed by inverting the logic of A1. . Thereby, the bit error of the signaling multi-frame multiplexed signal due to the signal degradation on the transmission path can be reduced, and the trouble of erroneously performing the bandwidth control of the packet signal can be prevented.

  The multiplexing unit (6-8) includes a digital signal output from the voice input processing unit (6-4), a digital signal output from the packet input processing unit (6-5), and a signaling multiframe generation unit (6 −13), the signaling multiframe signal (6-15) generated by the PCM encoded signal multiplexing timing signal (6-9), the packet multiplexing timing signal (6-11), and the signaling multiframe signal multiplexing timing signal ( 6-14), and multiplexes into time slots TS of signal transmission channels divided at predetermined time intervals, respectively, and transmits them to the transmission line (6-16). The multiplexed signal transmitted at a preset transmission rate is input to the transmission apparatus 202 on the reception side via the transmission path (6-16).

The multiplexing unit (6-8), when the multiplexing timing signal (6-7) is not output from the transmission band control unit (6-6) (when there is a signaling control signal), the PCM transmission signal (6-10) ) Is multiplexed in a time slot assigned in advance by the PCM encoded signal multiplex timing signal (6-9), and the multiplex timing signal (6-7) is output from the transmission band control section (6-6) ( When there is no signaling control signal), a packet multiplexed timing signal (6-11) for placing the transmission packet signal (6-12) in the time slot of the corresponding PCM transmission signal (6-10) is output and transmitted. The packet signal (6-12) is multiplexed.
[Receiver]
The transmission device 202 on the reception side includes a separation unit (6-19), a reception band control unit (6-23), an audio output processing unit (6-29), a packet output processing unit (6-30), It is comprised with a signaling multi-frame receiving part (6-22).

  The separation unit (6-19) separates the signal received from the transmission line (6-16) for each time slot (TS1 to TSn), and outputs each signal to the voice output processing unit (6-29) or the packet output. The data is output to the processing unit (6-30) and the signaling multiframe receiving unit (6-22). For example, the PCM reception signal separation timing signal (6-25) and the PCM reception signal (6-26) are separated and output to the voice output processing unit (6-29), and the packet separation timing signal (6-27) is output. The received packet signal (6-28) is separated and output to the packet output processing unit (6-30). Similarly, the signaling multiframe signal separation timing signal (6-20) and the signaling multiframe signal (6-21) are separated and output to the signaling multiframe reception unit (6-22).

  The signaling multiframe receiving unit (6-22) extracts the signaling control signals (A1 to Am) from the signaling multiframe signal (6-21) separated by the demultiplexing unit (6-19), and outputs the audio output processing unit (6 -29) and the reception band controller (6-23).

  If the signaling control signals A1 to Am output from the signaling multi-frame receiving unit (6-22) are in the state without signaling control, the reception band control unit (6-23) starts from the corresponding time slot TS for voice. A separation timing signal (6-24) for separating the reception packet signal (6-28) is output to control the bandwidth of the separation unit (6-19), and the reception packet signal (6-28) and the packet separation timing are controlled. The signal (6-27) is output to the packet output processing unit (6-30). In this case, the PCM reception signal (6-26) together with the PCM reception signal separation timing signal (6-25) is fixed to ALL "1" and output to the audio output processing unit (6-29) to reproduce the silent state. .

  The audio output processing unit (6-29) decodes the PCM signal based on the PCM reception signal separation timing signal (6-25) and the PCM reception signal (6-26), and outputs the audio output signal (6-32) to the outside. Output to the handset of the connected phone. Further, a signaling output signal (6-31) corresponding to the presence / absence of signaling control is output to a telephone connected to the outside by the signaling control signals A1 to Am.

  The packet output processing unit (6-30) takes the received packet signal (6-28) into the frame buffer unit (6-30a) by the packet separation timing signal (6-27), and then outputs the packet output signal for each frame. (6-33) is output to an external device (router, personal computer, etc.).

In this way, whether or not a voice signal is transmitted is detected based on the presence or absence (ON / OFF) of a signaling control signal, and when a voice signal is not transmitted, a packet signal is temporarily assigned to the time slot. Thus, the transmission band as described in FIG. 2 of the first embodiment can be effectively used, and the transmission band of the packet signal can be expanded.
[Signaling multiframe timing example]
Next, an example of the presence / absence detection of a signaling signal and bandwidth control by the signaling multiframe method will be described with reference to FIG.

  FIG. 8 shows the audio input processing unit (6-) in the signaling multi-frame generated by the signaling input signal (7-1), the multi-frame timing signal (7-2), and the multi-frame timing signal (7-2). 4) to a timing signal (7-3) representing the timing of taking in the signaling signal (eighth frame), a signaling multiframe signal (7-4) composed of eight frames, and a signaling detection signal (7-5) ), A signaling confirmation signal (7-6), an audio signal time slot (7-7), and a packet signal time slot (7-8). Since the signaling data is fixed when the signaling multiframe number is “8” on the receiving side, the signaling detection signal (7-5) is detected at the eighth frame. Since the signaling signal is not valid, the presence or absence of signaling is determined at a timing delayed by one multiframe (eight frames) from the signaling detection signal (7-5) as shown in the signaling determination signal (7-6). It becomes.

  For example, in the case of FIG. 8, the absence of signaling is confirmed at timing T4, and the packet is transmitted to the audio signal time slot in the period (period from timing T4 to timing T5) in which the signaling confirmation signal (7-6) indicates no signaling. The signal is assigned and the packet signal (7-8) is expanded to the voice signal time slot (7-7).

  When the presence of signaling is determined again at timing T5, the time slot temporarily used for the packet signal is returned to the original time slot for the audio signal.

  In this way, whether or not a voice signal is transmitted is detected based on the presence or absence (ON / OFF) of a signaling control signal, and if a voice signal is not transmitted, a packet signal is temporarily assigned to the time slot. . As a result, it is possible to effectively use the transmission band and widen the transmission band of the packet signal.

  Although there is a delay of time T6 (maximum of about 2 msec (125 usec × 8 × 2)) until timing T5 at which signaling data is provided and voice data starts to flow, there is a practical problem because it is a voice communication such as a telephone call. Absent.

  Further, even when the voice input processing unit (6-4) is not mounted or when the power is turned off, the circuit design is made so that the signaling signal is turned off, so that the voice signal is not used. In addition, since the time slot for the voice signal is automatically allocated for the packet signal, the transmission band can be effectively used.

  Although the transmission system and the transmission band control method according to the present invention have been described with reference to the embodiments, the present invention can be implemented in various other forms without departing from the spirit or main features thereof. For this reason, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The present invention is defined by the claims, and the present invention is not limited to the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

100, 200, 900 ... transmission systems 101, 201, 901 ... transmission devices 102, 202, 902 ... transmission devices (1-1), (2-2), (6-2) ... Voice input signals (1-2), (5-1), (7-1) ... Signaling input signals (1-3), (2-3), (6-3) ... Packet input signals ( 1-4), (2-4), (6-4)... Voice input processing unit (1-5), (2-5), (6-5)... Packet input processing unit (1- 6), (2-8), (6-8)... Multiplexers (1-7), (2-13), (6-16)... Transmission lines (1-8), (2- 14), (6-19)... Separation section (1-9), (2-21), (6-29)... Audio output processing sections (1-10), (2-22), ( 6-30) Packet output processing units (1-11), (2-24), (6-3) 2) Voice output signals (1-12), (2-23) Signaling output signals (1-13), (2-25) Packet output signals (2-1), (6 -1), (6-31) ... signaling signals (2-6), (6-6) ... transmission band control units (2-7), (6-7) ... multiple timing signals ( 2-9), (6-9)... PCM encoded signal multiplexed timing signals (2-10), (6-10)... PCM transmission signals (2-11), (6-11). Packet multiplexed timing signals (2-12), (6-12)... Transmission packet signals (2-15), (6-23)... Reception band control units (2-16), (6-24) ) ... Separation timing signals (2-17), (6-25) ... PCM reception signal separation timing signals (2-18), (6-26) ... PCM reception No. (2-19), (6-27) ... Packet separation timing signals (2-20), (6-28) ... Received packet signals (5-2), (7-2) ... Multiple frame timing signals (5-3), (7-3) ... Timing signals (5-5), (7-5) ... Signaling detection signals (5-6), (7-6) Signaling confirmation signals (5-7), (7-7): Voice signal time slots (5-8), (7-8): Packet signal time slots (6-15), (6 -21), (7-4) ... signaling multiframe signal

Claims (10)

In a transmission system that multiplexes and transmits a voice signal and a signaling signal and a packet signal associated with the voice signal between transmission apparatuses in a predetermined time slot,
The transmission apparatus is
An audio input processing unit for inputting the audio signal and the signaling signal;
A packet input processing unit for inputting the packet signal;
A transmission band control unit that detects the presence or absence of the signaling signal and performs band control to allocate the packet signal to the time slot for the audio signal when the signaling signal is absent;
A multiplexing unit for transmitting a signal multiplexed by assigning a time slot to the voice signal, the signaling signal, and the packet signal according to band control of the transmission band control unit;
A separator that receives the multiplexed signal from the transmission path and separates the voice signal, the signaling signal, and the packet signal;
A reception band control unit that performs band control on the demultiplexing unit for demultiplexing the signal of the time slot for the audio signal in the absence of the signaling signal as the packet signal;
An audio output processing unit that outputs the audio signal and the signaling signal separated by the separation unit;
A transmission system comprising: a packet output processing unit that outputs the packet signal separated by the separation unit to the outside. The transmission system according to claim 1, wherein
The multiplexing unit is configured to transmit a signal obtained by multiplexing the signaling signal to the audio signal input from the audio input processing unit by a bit steal method and the packet signal input from the packet signal input processing unit. A transmission system characterized by transmitting a multiplexed signal by assigning time slots according to bandwidth control to a transmission line. The transmission system according to claim 1, wherein
The multiplexing unit is configured to transmit a signal obtained by multiplexing the audio signal input from the audio input processing unit to the audio signal by a signaling multiframe method and the packet signal input from the packet signal input processing unit. A transmission system characterized by transmitting a multiplexed signal by assigning time slots according to the bandwidth control of the transmission line. The transmission system according to any one of claims 1 to 3,
The transmission band control unit detects that the voice input processing unit is not installed or is powered off based on the presence or absence of the signaling signal output from the voice input processing unit, and allocates the packet signal to a time slot of the voice signal. Characteristic transmission system. In the transmission system according to any one of claims 1 to 4,
The transmission system according to claim 1, wherein the multiplexing unit multiplexes corresponding to a 1.544 Mbit / s digital hierarchy primary group interface. In the transmission system according to any one of claims 3 to 5,
The transmission system according to claim 1, wherein the multiplexing unit multiplexes corresponding to a 6.212 Mbit / s digital hierarchy secondary group interface. The transmission system according to claim 6,
The signal obtained by multiplexing the signaling signal by the signaling multi-frame method includes error correction function data. In a transmission band control method used in a transmission system for multiplexing and transmitting a voice signal, a signaling signal accompanying the voice signal and a packet signal in a predetermined time slot between transmission devices,
Detecting the presence or absence of the signaling signal associated with the audio signal, and performing bandwidth control for assigning the packet signal to the time slot for the audio signal when the signaling signal is not present, the audio signal, the signaling signal, and the A time slot is allocated to the packet signal and the multiplexed signal is transmitted to the transmission line,
When the multiplexed signal is received from the transmission path and separated into the voice signal, the signaling signal, and the packet signal, the voice signal in the absence of the signaling signal by detecting the presence or absence of the signaling signal A transmission band control method comprising: performing band control for separating a signal in a time slot for use as the packet signal, and outputting the separated voice signal, signaling signal, and packet signal to the outside. The transmission band control method according to claim 8, wherein
The transmission band control method, wherein the signaling signal is multiplexed with the audio signal by a bit steal method. The transmission band control method according to claim 8, wherein
The transmission band control method, wherein the signaling signal is multiplexed with the voice signal by a signaling multiframe method.

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