Voice signal converting device

• US 4,403,322 A
• Filed: 07/02/1981
• Issued: 09/06/1983
• Est. Priority Date: 07/02/1980
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kato, Takao, Watanabe, Noboru, Horiki, Akira, Takemura, Tetsuo
• Primary Examiner(s): Olms, Douglas W.
• Application Number:
  US06/279,813
• Time in Patent Office: 796 Days
• Field of Search: 370/110.1, 370/111, 179/2 DP, 340/347 DD
• US Class Current: 370/522
• CPC Class Codes: H04J 3/125 One of the channel pulses or the synchronisation pulse is also used for transmitting monitoring or supervisory signals

Abstract

A voice signal converting device is adapted for a digital communication network which handles digitized voice signals and data signals simultaneously or equally. A bit for discriminating whether a signal in communication is a voice signal or a data signal is applied in a digital signal channel. The voice signal converting device is connected to a digital communication path to detect the discrimination bit from the incoming signal in such a manner that when a bit group corresponding to the discrimination bit represents the voice signal, the bit group is converted into a predeterminedly correlated bit group and delivered out and when the bit group corresponding to the discrimination bit represents the data signal, this bit group is delivered out in its original form. Consequently, even when the voice signal and the data signal coexist in one communication, speech quality of the voice signal and bit integrity of the data signal can be guaran

Claims

1. A voice signal converting device adapted for a digital communication network which handles digitized voice signals and data signals simultaneously comprising:

means for detecting a discrimination bit from a signal coming to an incoming digital communication path, said discrimination bit being set in a digital signal channel for discriminating whether a bit group corresponding to that discrimination bit represents a voice signal or a data signal;

means for converting the bit group in the digital signal channel coming to said incoming digital communication path into a predeterminedly correlated bit group; and

means responsive to results of detection by said detecting means so that when the bit group corresponding to the discrimination bit represents the voice signal, the correlated bit group resulting from the conversion by said converting means is selected and delivered to an outgoing digital communication path and when the bit group corresponding to the discrimination bit represents the data signal, this bit group in its original form is selected and delivered out.

2. A voice signal converting device according to claim 1, wherein said converting means comprises:

serial-parallel conversion means for serially receiving the bit group in the digital signal channel coming to said incoming digital communication path and producing a parallel output;

a conversion memory for receiving an input bit group in the form of the parallel output from the serial-parallel conversion means and converting the input bit group into an output bit group which is correlated to the input bit group pursuant to a predetermined arithmetic law and then delivered out of the memory; and

parallel-serial conversion means for serially transmitting the output bit group from said conversion memory onto the outgoing digital communication path.

3. A voice signal converting device according to claim 2, wherein said conversion memory comprises a read only memory for accommodating a code conversion table which receives, as an address input, the input bit group in terms of a first coding system and delivers, as a data output, the output bit group in terms of a second coding system corresponding to the address input.

4. A voice signal converting device according to claim 2, which further comprises a shift register for delaying the signal coming to the incoming digital communication path by a predetermined delay and producing a delayed output, said shift register being used as said serial-parallel conversion means incorporated in said converting means.

5. A voice signal converting device according to claim 1, wherein said detecting means comprises a flip-flop which latches said discrimination bit in the signal coming to the incoming digital communication path in response to a clock signal which is synchronized with the allotment of the discrimination bit set in the digital signal channel.

6. A voice and data signal transmission system for use in a digital communication network in which digitized voice signals and data signals are treated simultaneously comprising:

(a) means for applying to each time slot within a channel corresponding to a service call a bit for discriminating whether the signal in communication is a voice signal or a data signal when communication is established between terminal units via the digital communication network;

(b) a plurality of voice signal converting means each including means for detecting the discrimination bit from each signal time slot coming to an incoming digital communication path, converter means for converting a bit group in the digital signal channel coming to said incoming digital communication path into a predeterminedly correlated bit group pursuant to a predetermined arithmetic law, and means responsive to results of detection by said detecting means so that when the bit group corresponding to the discrimination bit represents the voice signal, the correlated bit group resulting from the conversion by said converter means is selected and delivered to an outgoing digital communication path and when the bit group corresponding to the discrimination bit represents the data signal, this bit group in its original form is selected and delivered out, the type of said plurality of voice signal converting means being determined in accordance with the arithmetic law of said converter means; and

(c) means for selectively connecting one of the various types of voice signal converting means pursuant to a desired arithmetic law in a digital link connecting terminal units in communication.

7. A transmission system according to claim 6, wherein said discrimination bit applying means allots the discrimination bit to the least significant bit of a PCM 8-bit code in the channel corresponding to the service call, whereby the remaining 7 bits represent the voice signal or the data signal.

8. A transmission system according to claim 6, wherein said various types of voice signal converting means are connected in a digital multiplex communication path and adapted for multiplex use for a plurality of multiplex channels.

9. A transmission system according to claim 6, wherein said selective connection means determines the voice signal converting means to be selectively connected in accordance with area of the calling terminal unit and the called terminal unit.

10. A voice signal converting device adapted for a digital communication network capable of transmission and reception by effecting switching between digitized voice signal and data signal during one communication as desired comprising:

an incoming digital communication path connected to a first unit for transmitting a digital signal, for transmitting the digital signal fed from the first unit with inclusion in each time slot of an information section of a predetermined number of bits representing the voice signal or the data signal and a coding section of a predetermined bit number indicating that information in the information section represents either the voice signal or the data signal;

means for detecting the coding section in the digital signal being transmitted to the incoming digital communication path;

selective conversion means responsive to results of detection by said detecting means so that when the information section corresponding to the coding section in the same time slot represents the voice signal, a bit group in said information section is converted into a predeterminedly correlated bit group and delivered out and when said information section represents the data signal, the bit group in said information section is delivered out in its original form; and

an outcoming digital communication path connected to a second unit for receiving the digital signal, for transmitting the information section and the coding section corresponding thereto delivered from said selective conversion means with these sections included in the same time slot in response to the coding section sent from said incoming digital communication path.