FI103559B - Method and apparatus for transmitting sound - Google Patents

Description

103559

Method and apparatus for transmitting sound Förfarande och anordning för att överföra ljud

Object of the invention

The invention relates to a method of voice transmission, and in particular to a method of voice transmission, which comprises converting a voice such as speech into a digitalized form and / or restoring it to an analog form. The invention also relates to a system according to the preamble of claim 9. The invention further relates to a device according to the preamble of claim 12.

Background of the Invention

The so-called LAN phones (LAN = Local Area Networking) are known to a person skilled in the art. In a LAN telephony arrangement, the terminal equipment consists of a suitable data processing device, such as a microcomputer, a so-called. the sound card and the phone memory device attached to the sound card. The terminal equipment is most often connected in a so-called. functionally via a network interface card, e.g., to a local data network, which may be connected via an adapter to a public telecommunications network. The local area network may be, for example, a LAN or an ATM-LAN local area network based on Ethernet, IsoEthernet, Novell, etc.

The communication network may be, for example, a telephone network such as a PSTN (Public Switched Telephone Network), a PSPDN (Packet Switched Public Data Network), various cellular networks, or an Integrated Services Digital Network (ISDN) or B-ISDN Broadband ISDN). Access to a public telephone network may also have been made via larger ("public") networks, such as the Internet.

The sound card fitted to the data processing device comprises means for performing the A / D (analog-to-digital) conversion and the D / A (digital-to-analog) conversion. The A / D converter is used to "record" the speech -4 and convert it to digital, and the D / A converter is used to produce 2,103,559 correspondingly intelligible audio to the speakers. Such A / D and D / A converters include, so-called. Sound cards that enable full duplex operation are known per se to those skilled in the art and are therefore not described further here.

Existing LAN phones based on computers such as PC or Macintosh ^ M compatible microcomputers, various workstations and the like, and typically Windows ™ or similar applications, have achieved many useful features, such as being able to digitally transmit speech in various existing data networks. Thus, they extend the range of the computer connected to the network to include telephony without significant line costs. LAN phones can take advantage of pre-existing sound cards and network cards, which means that there are no significant hardware costs involved in deploying a telephone feature, especially since the additional equipment to be connected to the computer is simple, including only the handset and the necessary connectors. Because the terminal is a programmable road machine, it can easily and flexibly provide numerous phone-facilitating solutions, such as various office automation services, telephone directories, telephone traffic databases, and the like, through programming alone.

However, the known solution also has a number of weaknesses. Problems have occurred during the use of the LAN phone. when several software applications seek to utilize the same sound card at the same time, a situation that often occurs e.g. the so-called. multimedia applications. An example of this is where the phone is ringing while the CD player or other multimedia application is in active mode. Conflicts between programs and applications and / or prioritization between them have not been satisfactorily resolved. A LAN phone is also dependent on certain types of sound cards. In some cases, the data processing capacity required for voice processing, which is absent from other applications, has also been identified as a problem.

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Especially older computing devices usually do not have the functionality of an integrated sound card, so the card should be purchased and installed separately. However, not all computing devices even have the space and / or capacity and / or even the ability to connect to such a discrete audio card.

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OBJECTIVES OF THE INVENTION The object of the present invention is to eliminate the drawbacks of the prior art and to provide a completely new solution for use in voice communication, in particular telephony via various data processing equipment, permanently or temporarily connected to different data networks.

It is a further object of the invention to provide a solution by which voice telephony or the like can be transmitted to a digital signal in a telecommunication network in which the telephone terminal is a microcomputer, workstation or the like, which is it is not necessary to have a special sound card to handle telephone traffic.

A further object of the invention is to provide a solution by means of which a printer port, preferably a printer port allowing parallel connection, can be utilized in telecommunication.

It is a further object of the invention to provide a solution in which the need for data processing capacity of a data processing device to perform telephone traffic is less than known solutions.

. It is a further object of the invention to provide a solution that avoids the problem of prioritizing sound cards.

Another object of the invention is to provide a solution according to which the device is independent of the type of the data processing device, i.e. it can be connected via a driver to any data processing device having a suitable free port.

It is a further object of the invention to provide a solution in which the digitized audio signal is preferably transmitted at the same rate to the handset device as that at which the digital signal is transmitted from the handset device.

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Description of the Invention

The invention is based on the basic idea that by providing at least one A / D or D / A conversion in a device separate from a data processing device, such as a handset part, and operatively connecting this separate device to a data processing device through its normal interface device such as a printer port or the like. a device which accomplishes the objects of the invention.

More specifically, the method according to the invention is essentially characterized by what is set forth in the appended claims 1 to 8 and in particular in the characterizing part of the independent claim 1. The system according to the invention is essentially characterized by what is set forth in the appended claims 9 to 11 and in particular in the characterizing part of claim 9. The device according to the invention is essentially characterized by what is stated in the appended claims 12 to 16 and in particular in the characterizing part of claim 12.

According to a preferred embodiment of the invention, the arrangement comprises a computer, such as a PC or Macintosh compatible microcomputer or workstation, which is operatively connected to a data network via a suitable link or connection means. The connection can be made using either a wired or wireless connection. A suitable handset device is operatively connected, either wired or wirelessly, to the computer through its standard interface, which is usually provided for another function / accessory. The preferred solution utilizes a printer port that is generally free for network use as the interface. Particularly preferred is a parallel port type printer port.

According to the invention, the handset means comprises means for providing at least one D / A and / or A / D conversion. In a preferred embodiment, the handset means comprises separate means for providing both A / D and D / A conversion. The handset device has at least one microcontroller means for controlling the operation of the converters. There is thus no need for the signal from or to the handset device to be processed on the computer except for its control and possible buffering between the computer and the network interface card providing the network interface and said interface port.

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One skilled in the art will appreciate that the terms data network, telecommunication network, or network generally refer to a solution that enables communication between at least two terminals. Thus, for the purposes of this disclosure, the term "network" is understood to include all types of wired and / or wireless connections connecting different terminals, which may be either closed networks with a minimum of two terminals and open networks with an unlimited number of connected devices. For example, a computer network may consist of the Internet or different combinations or variations of network solutions.

The invention provides a method and arrangement of voice transmission which is easy to implement with the help of existing sub-components, but which achieves a significant advantage in the digital form of telephony in various networks. Among the benefits to be achieved are: the fact that a computer's sound card is free for other tasks, such as multimedia applications, eliminates the problem of prioritizing telephony. In addition, the computer's capacity is no longer needed for the actual speech processing, but only for controlling the network card and controllers, etc. for low-capacity assistance. Further, in the handset device of the invention, it is also possible to perform some of the general processing, control and buffering of the signal. Connecting the handset device according to the invention to a computer is essentially easy as it takes place using standard connectors and without the need for mechanical installation of a sound card. The cost of acquiring electronics, wires, etc., required to carry out the invention is also substantially lower compared to the cost of the prior art sound card, its interface electronics, and connectors, wires, and the like. In addition, the operating voltage required by the handset device can be taken directly from an interface such as a printer port, and thus no additional voltage source is required. The handset according to the invention is not dependent on the type of computer but can be connected to any computer with a free port such as Mac, Amiga and Unix workstations by means of a suitable device driver.

The invention and other objects and advantages thereof will now be described, by way of example, with reference to the accompanying drawing, in which like reference numerals in the various figures refer to like features. It is to be understood that the following exemplary disclosure is not intended to limit the invention to the specific forms set forth herein, but on the contrary is intended to encompass all modifications, equivalents, and variations within the spirit and scope of the invention as defined in the appended claims. It is further noted in this connection that the term handset refers to any device which includes a microphone portion for receiving speech or the like, and / or a sound reproducing portion for speech or the like, and is intended for use in unidirectional or bidirectional transmission of sound.

Lvhvt summary of drawings

Figure 1 shows a simplified schematic representation of a telephone system including both conventional telephone equipment, a prior art LAN telephone system and a telephone system according to the invention.

Figure 2 shows a more detailed and partially sectional view of an embodiment of the terminal apparatus according to the invention.

Figure 3 is a diagram illustrating an embodiment of the invention.

Figure 4 is a more detailed schematic representation of the handset portion of the embodiment of Figure 3.

Figure 5 is a sectional view of a handset part according to the invention. Description of Preferred Embodiments

Fig. 1 is a highly simplified diagrammatic view of a telephone communication system comprising conventional telephone equipment 3, wireless or so-called. mobile telephones 2 (such as GSM, NMT, ARP), prior art LAN telephones 1 comprising a sound card 1 ', and network telecommunication devices 10 according to the invention. A conventional land line may be replaced by an ISDN digitized land line. The various telephone systems are described herein to clarify the differences between them and to illustrate the fact that various network systems 4, 6, and thus the telephone equipment 1, 2, 3 and 10 generally designated 8, can communicate via suitable links 5 (gateways).

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Multiple computers 20 may be connected to one LAN 4. The signal is transmitted from the LAN and LAN 4 via link 5. The link is, for example, a gateway that can perform signal conversion between audio coding and digital encoding of a computer and e.g. a computer that monitors the location of users identified by a subscriber number and a computer username. For the connection to be possible, the computer 20 must be "logged in." From said gateway 5, the call is routed to a telecommunication system such as 2 or 3, which may consist of exchanges such as the Ericsson MD110 or the like. such as the Ericsson AX Center, which still has a functional connection to terminals such as cordless or cordless phones or a handset connected to a computer.

If you want to use different types of telephone service, so called. The intelligent network services IN (Intelligence Network) can be used, for example, through the aforementioned exchanges and exchanges, such as the Universal Personal Telecommunication (UPT) service, so that the subscriber of the service can be reached at one or more locations, i.e. addresses.

When making a call from a computer 20 connected to the network 4 to another machine on the same network, it is not necessary to direct the call to a conventional telephone system, which may remain "internal" to the network.

The network 4 formed by the computers 20 may also be an Internet network, to which the PC 20 or the PC 20, for example, is connected. The PC 20 may consist of a central processing unit (CPU), memories such as program and main memory (e.g., ROM, RAM, hard disks), cards for providing additional functions, a bus to connect various components and functions, and a network interface. The input and / or output of the PC can be displayed, for example, on a screen or a printer. The user can enter data into the machine 20 using a keyboard, mouse or similar input device.

Current PCs usually include multimedia media for processing image, sound and text. The PC then has, for example, a sound card or the like, to which a microphone and / or a loudspeaker can be connected for transmitting and receiving speech or the like. The microphone and / or loudspeaker may be embedded in the PC 20 or e.g. its display, or may be external or e.g. in the form of a headset. For the data network, the machines have a network card that provides network access.

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Fig. 2 is a more detailed and partially cut away diagrammatic view of a telephone terminal apparatus according to the invention comprising a microcomputer 20 as a data processing device, showing its backside 21 so that its various ports such as 22, 25, 27 and 28 are clearly visible. The skilled artisan will understand the known uses of various interface ports, such as interfaces for said printer, keyboard, mouse, monitor, modem, network interface, and the like. Therefore, the functions or structure of the various ports are not described here more than merely by way of example, stating that for example printers can be used for printers. 9-pin serial port or 25-pin parallel port, a mouse can use a 6-pin round port and a monitor can be used with a 15-pin port. For the sake of clarity, Fig. 2 does not show a sectional view of the handset 10, except for other peripherals of the computer 20.

The handset 10 is connected via a wire 19 and a connector 23 at its end to a common printer port 22, which is preferably a so-called. parallel interface port. It is advantageous to utilize an Enhanced Parallel Port (EPP) port, but any two-way port currently in use, preferably at least 64 kbit / s, is suitable for this. The handset 10 shown in Fig. 2 includes a single microcontroller 14 operatively connected via wires 13 and 15 to the speaker 16 and microphone 18 respectively. The microcontroller unit 14 controls the operation of the A / D and D / A converters fitted thereto.

It should be noted that although only one microcontroller is sufficient, such an arrangement generally requires more complex programming procedures. When using two microcontrollers 12, 14 (Fig. 5), programming one operation is essentially simple, while combining and programming two functions so as to achieve good simultaneous timing is substantially more complicated. Because of the low cost and footprint of microcontrollers (e.g., 18 feet), two or more microcontrollers and circuits can be used instead of one larger, e.g., 40-foot controller.

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The microcontroller 12 embedded in the housing 11 of the handset 10 includes a D / A converter for converting, e.g., an 8-bit digital signal from the computer 20 into an audible and intelligible sound output by loudspeaker means 16. The second microcontroller 14 includes an A / D converter provided with a microphone. The 18 incoming signals are read in digital format. The handset may also comprise a filter for filtering the incoming signal with, for example, a software digital filter 9 103559 mm. to limit its bandwidth and / or filter noise. Correspondingly, handset 10 may, for example, undergo signal processing to compress / decompress the signal. In order to synchronize the data flow, it is preferable that the controllers 12 and 14 are also interconnected by a wire 17 for commuting between them.

The power consumption of the handset device 10 according to the invention is so low that the required operating voltage can be adapted to be taken directly from the printer port 22, thus avoiding the use of an additional voltage source. However, an additional voltage source can also be fitted to the handset 10 if a specific application, such as an alarm placed in the handset or the like, requires it.

It should be noted that the functional connection of the handset 10 to the computer 20's network card can also be accomplished over a wireless connection, whereby the printer port device 22 is replaced by a corresponding port receiver device operatively connected to the network card. Such suitable devices are known, for example, in the field of telephone and audio technology, in connection with wireless mice or keyboards, or in the field of remote controls.

Figure 3 illustrates a schematic representation of the operation of the system of the invention. As shown in Figure 3, the transmission of a digital signal containing audio data in both directions can be controlled by a so-called. with the interrupt driver. To be executed by the processor of the computer delimited by the dotted line 20. in the example, control of the signal transfer and control of the operation of the buffering means 32 are provided. Some of these functions may also be adapted to be performed by the control electronics placed in the handset 10, if necessary. Compared to the prior art, this represents a substantial reduction in the computing capacity of the computer 20 which must be reserved to handle telephony.

The network card device 30 is a special Ethernet card shown in the diagram, but of course the device between the data processing device 20 and the network can be of any suitable type without departing from the spirit of the invention.

Fig. 4 is a more detailed diagram showing the components and connections of the handset device 10 of Fig. 3, starting from the connector 23, which comprises IRQ and Strobe representing control signals 103559 and interfaces D0 ... D7 illustrating information bits. In the example, the microcontroller 14 containing the A / D converter is a processor known per se and is designated as PIC16C71. In the example, a known device of type designation AD558 is used as a D / A converter.

It should be noted that the filter 25 shown in Figures 3 and 4 is not always necessary, and that the filtering means may also be included in the microphone 18. In addition, the electronics housed in the handset may be adapted to perform, either fully or partially, functions 32 and network card 33.

In the method according to the invention, the audio signal from the microphone 18 is read by an A / D converter 14 'of the microcontroller 14 fitted to the handset 10, whereby it is converted to a digital signal. It is possible, but not necessary, to filter the signal as a suitable filter 25, such as a programmable digital filter, e.g. to limit its bandwidth or to filter noise. The digital converted signal is transmitted through a functional connection 19 to the printer port 22 of the computer 20, through which it is further transmitted through a buffer 32 to the network card 33. The signal from the network card is further transmitted to the communication network 8 in a known manner.

Correspondingly, the signal from network 8 is first received by the network card. The signal recognized by the central unit of the computer 20 is routed through buffering to the printer port 22, and thereafter through a connector 23 and a connection 19 to a microcontroller 12 fitted to the handset 10 where it is converted by a D / A converter 12 'to an audio signal.

The D / A conversion may be performed by a D / A conversion circuit including a resistor network (ladder) over which a reference voltage is applied. The circuit turns ON / OFF the resistors according to the status of the input bits. The result is a current that is directly proportional to the given binary number. The current is converted to voltage by an operational amplifier, which is usually built into the D / A converter. The circuit thus produces an output voltage that is proportional to the number input. By entering numbers in rapid succession, for example at 125 με intervals (8 kHz), the telephone's voice can be produced.

Alternatively, the D / A conversion may be performed by PCM (Pulse Code Modulation) or PWM (Pulse Width Modulation) technology, in which speech data is transmitted in pulses dated to code 10 103559. In this case, a small number corresponds to a short pulse and a large number to a long pulse. The D / A converter can be replaced by such a system if the microcontroller has a PWM output, that is, if it is capable of generating sufficiently short pulses proportional to the number input. The above 125 / s cycle requires an resolution of better than 0.5 με at 8 bits. In practice, however, the speed requirement of 1 digit / 125 yt / s prevents pulses from being generated, for example, by a simple program loop, since the time required by the controller command is in the order of 0.5 ... 1 // s / instruction. In some microcontrollers of the PIC series, PWM support is available, whereby a number can be supplied to the controller counter, e.g. The pulse string can then be converted to analog form, that is, as such, by simple low-pass filtering, which in practice "rounds" the pulse string to analog form.

If the microphone is read with an 8-bit A / D converter, the signal can be transmitted to the computer 20, for example, in two 4-bit nyblenes. The D / A converter 12 'of the microcontroller 12, in turn, receives a digital signal, e.g. 8-bit, from the computer 20 and converts it into an audio signal which can be represented by the loudspeaker means 16. It is also advantageous for the controllers 12 and 14 to communicate with each other to synchronize the data stream.

The printer interface, or printer port, that comes with computers is usually what is called a printer port. a parallel interface that enables bidirectional communication. The computer can write to or read from the printer port at about 100,000 bytes per second. According to the preferred embodiment described above, depending on the printer port, a communication protocol is used in which the same number of bits is transmitted, e.g. 8 bits in both directions or depending on the direction e.g. 8 bits outwards per handset and 4 bits per computing device.

Functions such as alerting an incoming call, dialing a number and various memory functions are advantageously performed e.g. LAN Phone System Emotional. come on the way.

The invention thus provides a method and an apparatus which provides significant advantages in the use of so-called "computer" adapters. in the field of telephony over network telephones.

It should be noted that the foregoing examples of embodiments of the invention are not intended to limit the scope of the claims as set forth in the claims, but that modifications and variations apparent to one skilled in the art through the foregoing description and drawings are within the scope of the invention. An example of such a modification is a solution in which the speaker means is located in a physically separate medium from the microphone means, or a solution in which the dial pad is also located in the handset, whereby the dial signal can also be provided through a corresponding interface port. A control command for this may be given by means of control means adapted to the handset or to the data processing device.

Claims (16)

A method for transmitting audio in digital form, in which method the sound is received with the microphone means of the handset, the received sound is converted into said handset from analog form to digital form and the audio signal in digital form is transmitted through an operative connection to a data processing device, wherein it is further transmitted through an operational connection to a data network. A method for transmitting audio in digital form, in which method a data network operatively coupled data processing device receives an audio signal in digital form, said signal in digital form is further transmitted through an operative connection to a decoder and then converted in the decoder to an audio signal. for rendering using a speaker remedy. Method according to claim 1 or 2, characterized in that said digital signal transfer between the handset and the data processing device is carried out through a connection port, preferably a printer port, which is intended for the additive means of the data processing device. Method according to claim 3, characterized in that said transmission is performed through a parallel connection point type port. . 5. A method according to any of the preceding claims, characterized in that the digital signal is transmitted both from the handset to the data processing device and from the data processing device to the handset, and that the digital signal is transmitted from the handset to the data processing device in a form other than when the digital signal is transmitted to the data handset. Method according to any of the preceding claims 2 ... 5, characterized in that the digital signal is transmitted in the form of coded pulses, and it is converted into an audio signal with low pass filtering. Method according to any of the preceding claims, characterized in that sound received with the loudspeaker means is filtered by programmatic digital filtering. 103559 17 Method according to any of the preceding claims, characterized in that the sound transmitted is telephone traffic audio. A system for transmitting audio in digital form comprising a data processing device (20), means (33,34) for operatively coupling the data processing device (20) to the data network (8), and a data processing device (20). ) operably coupled earphone, equipped with a microphone means (18) receiving audio signals and / or a loudspeaker means (16) etching audio signals, characterized in that the earphone (10) comprises at least one microcontroller (14) for converting the audio signal received from the microphone means (18) to a digital signal and for transmission to the data processing device (20) through an operative contact (19, 22, 23) and / or to receive and convert (12) the digital signal received through an operative connection (19, 22). 23) from the data processing device (20) to be transmitted with the loudspeaker means (16) as an audio signal. A system according to claim 9, characterized in that the operative connection between the handset (10) and the data processing device (20) has been established through a connection port (22), advantageously a printer port, intended for the additive means of the data processing device. A system according to any of claims 9 or 10, characterized in that the data processing device (20) further comprises control means (30) and / or programmatic means for controlling the signal transmission, a buffer means (32) for buffering the signal, to be transmitted, and a network card means (33) intended for traffic between the network (8) and the data processing device (20). 12. A receiver comprising microphone means (18) for receiving sound and / or loudspeaker means (16) for reproducing sounds, further comprising at least one microcontroller (14) for converting the audio signal, such as the microphone means (16). received, in digital form to be sent to the receiving means (20) of the digital signal and / or to convert (12) the received digital signal to be transmitted with the loudspeaker means (16) as audio signal, and the means (19, 23) to provide an operative connection between said at least one microcontroller (14, 12) and the means (20) receiving and / or sending the digital signal. 103559 18 13. A decoder according to claim 12, characterized in that the means for accomplishing the operative interconnect comprises a connection means (23) adapted to be placed at the connection port (22), advantageously for a printer port providing a parallel connection, intended for data processing. the additive of the handling device. A decoder according to any one of claims 12 or 13, characterized in that it comprises at least two microcontroller means, the first microcontroller (12) being operatively coupled to a D / A converter (12 ') for converting the digital signal to a digital signal. the audio signal and the second microcontroller (14) are operatively coupled to an A / D converter (14 ') to convert the audio signal to a digital signal, and that there is a communication connection (17) between the control means (12, 14). 15. A decoder according to any one of claims 12 to 14, characterized in that it further comprises filter means (25), advantageously programmable digital filter means, for filtering the audio signal. 16. A decoy according to any one of claims 12 to 15, characterized in that the operating voltage, as needed, is taken through the said operative connection ice (19, 23).