WO1999049630A1

WO1999049630A1 - Real-time audio to data and data to audio converter and method

Info

Publication number: WO1999049630A1
Application number: PCT/GB1999/000912
Authority: WO
Inventors: Donald Joseph Gariepy; George James Stoulil
Original assignee: Donald Joseph Gariepy; George James Stoulil
Priority date: 1998-03-23
Filing date: 1999-03-23
Publication date: 1999-09-30
Also published as: AU3044399A

Abstract

A system for converting real-time audio into data and data into audio for use in transmitting an audio converted to data signal, typically a telephone conversation, over a data transport system, such as the Internet. The converter is hardware and thereby eliminates delays in a software converter and eliminates the need for computer calculations. The converter is positioned at the access site of a data transport system and comprises a telephone interface for linking telephone lines to the converter. The telephone interface is attached to a transmitter and a receiver, whereby the telephone interface receives audio signals and transmits the audio signal to a real-time converter. The real-time converter converts the audio signal received from the telephone interface to a data signal, the data signal is transmitted by the transmitter to a data transport system.

Description

- 1 -

^REAL-TIME AUDIO TO DATA AND DATA TO AUDIO CONVERTER _AND METHOD

Field of the Invention

The present invention relates to a real-time audio to data and data to audio converter, to a digital data protocol converter, and to data conversion methods.

Background of the Invention

The availability of the Internet as a world-wide, low cost, data transport system has prompted the development of software packages which convert voice signals on the microphone and speaker of a multi-media personal computer into data signals which can be transmitted over the Internet. The same software has also been used to permit a computer to convert voice signals from a telephone line to data signals which can be transmitted over the Internet. A problem arises with this software in that the time required to process the voice signal using software conversions of voice to data and data to voice causes a long delay between transmission of a voice signal (speaking) and reception of the voice signal (hearing). The delay which the sender perceives is twice as long as the time required to process his own voice signal because the receivers' reply signal is similarly delayed before it can be heard by the original caller. These conversions cause uncomfortable delays and pauses such that a normal conversation cannot be had over the Internet using this technique. What is desired therefore is a hardware based real-time voice to data and data to voice converter.

The Internet has also prompted the development of software packages which extend the forms of communication transmitted through the Internet. These forms of communication transmitted through the Internet include among others, voice signals, fax signals and video signals. Prior art software generally converts the original signals received into packets with frames and addresses that permit the signals to pass through the data transport system, typically the Internet, disguised as data signals. A problem arises with this software in that the time required to interrupt the signal and - 2 - produce a new signal by mathematical calculation causes a delay in the transmission. This delay causes a significant problem with interactive communications such as telephone conversations. Another problem that exists with the prior art is that it deals with a single voice channel, while modern telephone service transports multiple multiplexed voice channels, 24 channels at a time in the case of a Tl digital carrier system. What is desired therefore, is a hardware based real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter.

Summary of the Invention

In order to overcome the problems inherent in the prior art, there has been devised by a first aspect of the present invention a new and novel electronic circuit which converts a voice or other audio signal from a telephone into a digital signal for transmission over a data transport system, typically the Internet, to a similar unit at a remote location. The real-time converter of the first aspect of the present invention also converts the digital signal back to an audio or voice signal for reception as a sound or voice at the receiving end of the conversation. The real-time voice to data converter eliminates the calculations required by software and eliminates the need for a computer.

The real-time audio to data and data to audio converter of the first aspect of the present invention generally comprises a two way conversion means for converting audio signals to data signals and for converting data signals to audio signals. The converter of the first aspect of the present invention is positioned at the access site of a data transport system and comprises a telephone interface means for linking telephone lines to the converter. The telephone interface means is attached to a transmission means and a receiving means, whereby the telephone interface means receives audio signals and transmits the audio signal to a real-time converting means. The real-time converting means converts the audio signal received from the telephone interface means to a data signal, the data signal is transmitted by the transmission means to a data transport system. The receiving means of the present converter - 3 - receives the data signals from the data transport system, sends the data signals to the converting means, whereby the data signals are converted back to audio signals to be routed to the recipient as audio or voice signals.

In order to overcome the problems inherent in the prior art, there has been devised by a second aspect of the present invention a new and novel electronic circuit which converts data signals received from a digital telephone interface to packet data signals required by a data transport system protocol, typically the Internet protocol. The real-time converter of the second aspect of the present invention also converts the data packet signal back to a digital telephone interface signal for reception at the recipient end. The real-time digital telephone interface signal to packet data signal converter of the second aspect of the present invention eliminates the calculations required by software and eliminates the need for a computer.

The real-time digital telephone interface signal to packet data signal converter of the second aspect of the present invention generally comprises a two way conversion means for converting one format of data signals to another format of data signals. The converter of the second aspect of the present invention is positioned at the access site of a data transport system and comprises a digital telephone interface means for linking digital telephone lines to the converter. The digital telephone interface is attached to a transmission means and a receiving means, whereby the digital telephone interface means receives data signals in a digital telephone interface format and transmits this data signal to a real-time converting means. The real-time converting means converts the digital telephone interface data signal to a packet data signal format that is the protocol used by the Internet, the packet data signal is transmitted by the transmission means to a data transport system. The receiving means of the present converter receives the packet data signals from the data transport system, sends the packet data signals to the converting means, whereby the packet data signals are converted back to digital telephone interface signals to be routed to the recipient as digital telephone interface data signals. This conversion is performed in real-time without interrupting the normal flow of the telephone carrier system so that there is no perceptible delay in interactive communications, such as a telephone conversation. - 4 -

It is therefore an object and advantage of the first aspect of the present invention to provide a real-time audio to data and data to audio converter which eliminates software calculations and thereby eliminates uncomfortable pauses in a telephone conversation which takes place over the Internet. It is another object and advantage of the present invention to provide a low cost way of transmitting a telephone conversation over the Internet in real-time.

It is yet another object and advantage of the present invention to provide a hardware based, real-time voice to data and data to voice converter for added reliability to the transmission of a telephone conversation. It is still yet another object and advantage of the present invention to provide a real-time audio to data and data to audio converter that has flexibility in the hardware with which it is used.

It is therefore an object and advantage of the second aspect of the present invention to provide a real-time digital telephone interface signal to packet data signal converter which eliminates software calculations and thereby eliminates uncomfortable pauses in a telephone conversation which takes place over the Internet.

It is another object and advantage of the present invention to provide a low cost way of transmitting multiple telephone conversations over the Internet in realtime. It is yet another object and advantage of the present invention to provide a hardware based, real-time digital telephone interface signal to packet data signal converter for added reliability to the transmission of a telephone conversation.

It is still yet another object and advantage of the present invention to provide a real-time digital telephone interface signal to packet data signal converter that has flexibility in the hardware with which it is used.

It is still yet another object and advantage of the present invention to provide a real-time digital telephone signal to packet data signal converter that requires less space and power in its installation.

Brief Description of the Drawings - 5 -

Figure 1 is a block diagram of the audio to data and data to audio converter of the first aspect of the present invention.

Figure 2 is an environmental block diagram of the audio to data and data to audio converter of the first aspect of the present invention in its simplest form, as it is positioned at the access site of the data transport system provider.

Figure 3 is an environmental block diagram of the preferred embodiment of the audio to data and data to audio converter of the first aspect of the present invention, showing more than one sender and more than one recipient, all are connected through a telephone switch installed at a central Internet Service Provider. Each sender and each recipient can dial each other as desired. The telephone switch also allows each sender and each recipient to dial out through the existing telephone system to any destination on the telephone network. Figure 3 is an example of a user that is located locally to the central switch station.

Figure 4 is an environmental block diagram of the preferred embodiment of the audio to data and data to audio converter of the first aspect of the present invention, similar to Figure 3 and showing an example of a user that is located in a remote location to the central switch station.

Figure 5 is an environmental block diagram of the preferred embodiment of the audio to data and data to audio converter of the present invention, similar to Figure 3 and showing an example of a full time network user of the first aspect of the present invention.

Figure 6 is an environmental block diagram of the audio to data and data to audio converter of the first aspect of the present invention used with a different type of telephone switch, a switch/router which allows routing capability directly to the Internet backbone.

Figure 7 is an environmental block diagram of the audio to data and data to audio converter of the first aspect of the present invention wherein the audio signal that is converted to data is a video signal. A typical application of this use of the audio to data and data to audio converter is a security camera wherein it is desirable to transmit the images of the camera to a remote location. - 6 -

Figure 8 is a block diagram of the digital telephone interface signal to packet data signal converter of the second aspect of the present invention.

Figure 9 is an environmental block diagram of the digital telephone interface signal to packet data signal converter of the second aspect of the present invention in its simplest form, as it is positioned at the access site of the data transport system provider.

Figure 10 is an environmental block diagram of a typical application of the digital telephone interface signal to packet data signal converter of the second aspect of the present invention. Figure 10 illustrates that connections can be made between senders and recipients through local telephone switches or major telephone switch points.

Figure 11 is an environmental block diagram of a typical application of the digital telephone interface signal to packet data signal converter of the second aspect of the present invention and showing the connection between a sender and recipient using a local telephone switch.

Figure 12 is an environmental block diagram of a typical application of the digital telephone interface signal to packet data signal converter of the second aspect of the present invention and showing the connection between a sender and recipient using a major telephone switch point.

Description of the Preferred Embodiment

Referring now to Figures 1 to 7 in general, and in particular to Figure 1 and Figure 2 of the drawings, there is shown in Figure 1 a block diagram of the real-time audio to data and data to audio converter 10 of the first aspect of the present invention. Figure 2 is an environmental block diagram of the audio to data and data to audio converter of the first aspect of the present invention, in its simplest form, as it is positioned at the access site 12 of a data transport system provider 14, typically the Internet. The converter 10 of the first aspect of the present invention converts voice signals received by it from a phone line 16 into a data signal. This data signal is transmitted over the data transport system 18, to a similar remote location, at the - 7 - access site 20 of the remote data transport system provider 22. At the remote location, the data signal is converted back to a voice signal and is transmitted over a phone line 24 at the remote location as a voice signal, as seen in Figure 2.

The converter 10 of the first aspect of the present invention generally comprises a two way conversion means having a sender 26 and a recipient 28 as seen in Figure 2. Generally, both the sender 26 and recipient 28 have access to a similar converter 10 one, for the sender 30, positioned at the access site 12 of the data transport system provider 14 and one, for the recipient 32 positioned at the access site 20 of a recipient data transport system provider 22. The converters 30 and 32 work in a mirrored manner for both parties. By positioning the converter 10 of the first aspect of the present invention at the access site 12 of a data transport system provider 14, the converter 10 can transmit its data signal using a high quality T-l connection directly to the backbone 34 of the Internet. The backbone 34 of the Internet, as it is depicted most clearly in Figures 3, 4, and 5 uses the fastest links of the Internet, which bypass local connections. In this way, any delays which may be inherent on the Internet due to other numerous local connections, are bypassed, causing the transmission of the data signals to be the fastest possible.

While, in typical practice, the converter 10 of the first aspect of the present invention uses the Internet as the data transport system 18 for transmitting data signals, it is within the spirit and scope of the present invention to use any type of

Local Access Network (LAN) or Wide Area Network (WAN), a personal computer or mainframe computer, a server, bridge or router, a modem or a wireless distribution system.

In general, as seen most clearly in Figure 2, the converter 10 of the fist aspect of the present invention comprises the two way conversion means for converting audio signals to data and data signals to audio for a sender 26 and a recipient 28. The converter 10 works in a mirrored manner for both parties. Each converter 30 and 32 generally comprises a telephone interface means 36, as seen in Figure 1, for linking telephone lines 16 and 24 to the converter 10. In the preferred embodiment of the first aspect of the present invention, the telephone interface means 36 uses a four wire

E and M trunk to transmit audio signals from the telephone 38 to the converter 10 of - 8 - the first aspect of the present invention. It is also within the spirit and scope of the present invention to transmit audio signals to the converter 10 via a two wire E and M trunk, a two wire loop trunk, a fax line, a POTS line, a two-wire reverse battery trunk, a modem line, a microphone line, a speaker line, a DX line, a security and alarm circuit, a telemetering circuit or a broadcast circuit. The telephone interface means 36 is attached to a transmission means 40 and a receiving means 42, as seen most clearly in Figure 1, the telephone interface means 36 receiving audio signals and transmitting the audio signals to a converting means 44. The converter 10 of the first aspect of the present invention also generally comprises a real-time converting means 44 which converts the audio signal received from the telephone interface means 36 to a data signal or converts a data signal received from the data transport system 18, as seen in Figure 2, to an audio signal. The converting means 44 is attached at one end 46 to the transmission means 40 and at the other end 48 to the receiving means 42. The transmission means 40 of the first aspect of the present invention transmits data signals to the data transport system 18 and the receiving means 42 receives data signals from the data transport system 18.

More specifically, in the simplest form of the first aspect of the present invention, as seen most clearly in Figure 2, the sender 26 transmits an audio signal using the telephone interface means 36. The sender's telephone network 50 delivers the call to the converter 30 of the first aspect of the present invention at the access site 12 of the data transport system service provider 14, most typically the Internet Service Provider. At the data transport system provider 14, when the call is delivered, the converter 30 of the first aspect of the present invention answers, converts the audio signal to a data signal, and routes the data signal (converted voice of the caller) to a converter 32 positioned at the access site 20 of the recipient data transport system provider 22. When the audio signal is first received at the converter 30 of the sender's data transport system provider 14, the transmission means 40 in the form of a transmitter 52 transmits the audio signal to a receiving means 42 in the form of a receiver 54, as seen most clearly in Figure 1. The transmitter 52 and receiver 54 are both attached to the telephone interface means 36 which links telephone lines 16 and

24 to the converter 10. From the telephone interface means 36, the sender's audio - 9 - signal goes to a real-time converting means 44 where the sender's audio signal is converted to a data signal. From the converting means 44, the now converted data signal is sent over the data transport system 18 to the converter 32 at the recipient's 28 data transport system provider 22. The converter 32 at the destination data transport system provider 22 converts the data signal back to audio and the recipient

28 telephone interface 56, as seen as Figure 1, routes the audio signal to the ultimate destination. At this point, after the recipient 28 has received the sender's audio signal (voice), the recipient 28 responds and thereby now becomes the sender 26, whereby the process is repeated. More specifically, the sender 26 transmits an audio signal using the transmission means 40 of the converter 10, in the form of a transmitter 52. The transmitter 52 transmits the audio signal to a receiving means 42 in the form of a receiver 54. Attached to both the transmitter 52 and receiver 54 is the telephone interface means 36 for linking telephone lines 16 and 24 to the converter 10. From the telephone interface 56, the sender's audio signal goes to the real-time converting means 44 where the sender's audio signal is converted to a data signal. The data signal is transmitted over the data transport system 18 (typically the Internet) and is received by the recipient 28 at the recipient's converter 32 as a data signal. The data signal goes to the converter 32 of the recipient 28, where it is converted to an audio signal. The audio signal goes from the converting means 44 to the recipient's telephone interface 56 whereupon it is transmitted to the recipient as an audio signal or the sender's voice. The telephone network 58 for the recipient 28 answers and the reverse process takes place, all in real-time so that there are no uncomfortable gaps between sending and receiving an audio signal. Each of the converters 30 and 32 then, the sender's converter 30 and the recipient's converter 32 act as alternating senders and recipients. Each converter 30 and 32 is the same, just positioned at the access sites 12 and 20 for different data transport system providers 14 and 22. So, each converter 30 and 32, has a sender portion 60, when it acts as a sender 26 and a recipient portion 62 when it acts as a recipient 28, as seen in Figure 1. The sender portion 60 of the converter 10 accepts a balanced 600 or 900 ohm telephone signal on an amplifying means 64 in the form of an operational amplifier - 10 -

66. The operational amplifier 66 converts the balanced telephone signal into an unbalanced signal which is a ground reference signal required by a modulating/demodulating means 68 in the form of a modulator 70 of the converter 10. The modulator 70 of the converter 10 is a standard delta modulation or demodulation integrated circuit. It is, however, within the spirit and scope of the invention to use any type of suitable modulating or demodulating means 68. In the present instance, modulation is a function of transmission, so the modulator/demodulator 69 functions as a modulator 70 when positioned at the sender portion 60 of the converter 10 and demodulation is a function of reception, so the modulator/demodulator 69 functions as a demodulator 72 when positioned at the recipient portion 62 of the converter 10. In Figure 1, the same modulator/ demodulator 69 is shown at 70 and 72. When positioned at the sender portion 60 of the converter 10 the modulator/ demodulator 69 functions as a modulator 70, that is converts audio signals to data. When the modulator/ demodulator 69 is positioned at the recipient portion 62 of the converter 10 it functions as a demodulator 72, that is converts data signals to audio. A timing means 74 in the form of a crystal clock 76 synchronizes the operation of the converter 10. This high frequency clock 76 has its high frequency divided to a lower frequency clocking signal by a dividing means 78 in the form of a divider 80. The divider 80 then transmits these lower frequency clocking signals as a clocking pulse. The lower frequency clocking signals are used by the transmitter 52 of the converter 10. The modulator 70 samples the input ground reference signal one time for each clocking pulse received from the divider 80. The modulator 70 then outputs a 1 bit if the audio signal has increased or a 0 bit if the signal has decreased. An alternating 1 and 0 is sent by the modulator 70 if the signal does not change. The signal produced and output by the modulator 70 is thus an endless string of l's and 0's. Single bits, or even several occasional bits can be lost from the resulting bit stream with no real impact on the signal. An alternating 0 and 1 produces no change at all in the transmitted signal. The quality of the transmission from the modulator 70 is directly proportional to the speed of the clock 76 which is used to sample the audio signal, and can be arbitrarily changed by plugging a different crystal clock into the circuit board that is the converter 10, should it become - 11 - necessary to do so for a high quality radio broadcast or a similar application. The continuous stream of bits output from the modulator 70 must be converted into a string of ASCI I characters in order to be sent to a normal data transmission port 82 as a modem 84 would use it, to transfer data signals across the data transport system 18, as seen in Figure 2. An ASCII character consists of a short packet of eight information bits. It is framed by a start bit that is always 1 and ends with a stop bit that is always 0. In a continuous stream of information, there is therefore a 01 combination that separates every 8 bits of information. This frame is used by the data transport system 18, typically the Internet, to maintain synchronization, and to preserve these eight bit groups, which are coded such that each 8 bit group forms a single character or letter. The converter 10 of the first aspect of the present invention produces this framed 8 bit pattern by generating a 01 bit pattern repeatedly as every 9th and 10th bit in the divider 80. A gating means 86 in the form of a gate circuit 86 inserts this 01 pattern into the signal, thereby overriding whatever pattern formerly existed there, as seen in Figure 1. This process causes the data transport system 18, as seen in Figure 2, to see a continuous stream of ASCI 1 characters, which it will recognize as data and will transmit this data through the system in the normal fashion. The receiving means 42 of the converter 10, in the form of a receiver 54, as seen in Figure 1, will also see this 01. Since the 01 is a null combination in the modulator/demodulator 68, the 01 combination has no effect on the signal received by the receiver 54, other than to slightly reduce the quality of the signal. The gate circuit 88 produces some undesirable spikes in the bit pattern, which are removed by the gated flip-flop 90 to thereby produce a smooth ASCI 1 bit stream. The bit stream passes through a RS232 driver circuit 92 which converts the O to +5 volt logic signal received from the circuit of the converter 10 into a + and -12 volt signal which is used on the RS232 standard modem interface 94.

The continuous data signal is passed through the data transport system 18, as seen in Figure 2, and arrives at the receiver 54 at the recipient portion 62 of the converter 10 at the remote access site 20 of the data transport system 18. At the remote access site 20 the + and -12 volt signal is converted into the 0 and +5 logic signal by the 12 to 5 volt converter 95. This 0 and +5 logic signal directly enters the - 12 - demodulator 72 at the recipient's converter 32 where it is converted into voice. The 12 volt driver 92 converts the 5 volt signal of the converter 10 to a 12 volt signal as required by the RS232 interface 94. The 12 volt supply line 96 supplies the necessary voltage for the 12 volt driver 92 and the RS232 interface 94. The voice signal passes through a receive amplifier 97, which is a similar amplifier to the sender's operational amplifier 66. The receive clock pulses are provided by the same divider 80 that drives the transmitter 52 so that only one primary clock is required. The phase of the receive clock pulse from the divider 80 is continuously adjusted by a circuit in the receiver 54 such that the receive bits are always sampled in the center of each bit. This form of synchronization preserves a clean received signal.

In addition to transmitting voice signals in both directions, telephone applications also require supervision. Supervision refers to the signal generated when a telephone goes off hook and it is used to set up, hold and release telephone circuits at the appropriate time. The signal remains on as long as the conversation exists and ends when the user hangs up. There are two supervision signals required for any call.

One signal represents the sender 26 and the other represents the recipient 28. The converter 10 of the first aspect of the present invention uses the transmission of bits, and the absence of bit transmission to generate supervision. When the circuit of the converter 10 is idle, no bits are sent. When the circuit becomes active, the bit stream appears, and when the bit stream is received at the recipient's converter 32, it communicates an off hook condition for the sender 26 and an answering signal for the recipient 28. The bit stream is therefore always present to carry the voice signal when the circuit of the converter 10 is in use, and always absent when the circuit is idle and there is no voice to carry. When a call is delivered from the sender 26 to the sender's local converter 30, the M lead 98 of the 4 wire E and M interface changes from open to -48 volts to indicate an incoming call. When the M-lead 98 is open indicating the absence of a call, the ability to send the data stream across the data transport system 18 is disabled. When the M-lead 98 goes negative, indicating the presence of an outgoing call, the ability to send the data stream across the data transport system 18 is enabled, allowing a continuous data stream to be sent across the data transport system 18 to the recipient's converter 32. Within the recipient - 13 - portion 62 of the recipient's converter 32 is a bit detector circuit 100 that detects the presence or absence of a data stream. With the absence of a data stream indicating the absence of a call, the E-lead 102 is open indicating an on hook or idle condition. When the presence of a data stream is detected, indicating the presence of an incoming call, the E-lead 102 goes to ground indicating an off hook condition. When the off hook condition is detected by the telephone network 58 associated with the recipient's converter 32, the M-lead 98 transitions from open to -48 volts. This transition opens the gate 88, allowing the data stream to be transmitted over the data transport system 18 to the sender's converter 30. Detection of the data stream from the recipient 28 to the sender 26 converter 10 using the bit detector 100 transitions the sender's relay 104 to switch the E-lead 102 from open to ground indicating the answering of the call. Referring now to Figure 3 of the drawings, there is shown an environmental block diagram of the preferred embodiment of the audio to data and data to audio converter 10 of the first aspect of the present invention, showing more than one sender 26 and more than one recipient 28, all are connected through a telephone switch 106 installed at the central station 108 data transport service provider 14. Each sender 26 and each recipient 28 can dial each other as desired. The telephone switch 106 also allows each sender 26 and each recipient 28 to dial out through the existing telephone system 110 to any destination on the existing telephone network as shown by location 112 in Figure 3. Figure 3 is an example of a sender 26 that is located locally to the central switch station 108. In Figure 3 it can be seen that each station 114 in the converter network 116 as shown in Figure 3, has a converter 10 for converting audio signals to data and data signals to audio. The converter 10 is accessible to the end user either through a telephone switching means 118 in the form of a telephone switch 106 or a local telephone line

120, depending on the location of the user relative to his converter 10. For example, a client that is local to the central switch station 108 would reach the appropriate converter 10 by calling over the local phone line 120. After the sender's audio signal has ben converted by the converter 10 to a data signal, the resulting data stream is sent to an access server 122. The access server 122 puts headers and trailers on the data stream so the data will fit the data transport system 18 protocol for data - 14 - transportation. Then a router 124 routes the data from the access server 122 to the data transport system 18. The location of the sender 26 of a call is important to how the call is handled. In a first example, as shown in Figure 3, the sender 26 is local to the central switch station 108. The sender 26 calls the telephone switch 106 at the central switch station 108 via a local phone line 120 or an 800 number set up for this purpose. The telephone switch 106 answers the call and requests authorization of the sender 26. The sender 26 enters a prearranged authorization number and then the phone number of the person he wishes to reach. The telephone switch 106 analyzes the phone number the sender 26 has entered, consults its routing table and sends the call to the selected converter 126 based on the destination of the call, in the example of Figure 3, the station B converter 126. The telephone switch 106 may choose also to use existing local or long distance phone lines if the call is destined for a location which does not have a converter 10.

Another example of how the network 116 works is illustrated in Figure 4. Figure 4 is an environmental block diagram of the preferred embodiment of the audio to data and data to audio converter of the first aspect of the present invention, similar to Figure 3 and showing a sender 26 that is located in a remote location to the central switch station 108. In Figure 4, a sender 26 that is not local to the central switch station 108, a sender located at station A 128, calls his local station A converter 130, located at the station A data transport system access site 12, as seen in Figure 2. The station A converter 130 sends data via the data transport system 18 directly to its companion station A converter 132 located at the central switch station 108. The companion station A converter 132 at the central switch station 108 connects to the telephone switch 106, whereby the telephone switch 106 verifies authorization and selects the remote converter 10 to which the call should be sent, remote station D 134 in the example of Figure 4.

It is also within the spirit and scope of the present invention, to have full time converter network users as in the example shown in Figure 5. Figure 5 is an environmental block diagram of the preferred embodiment of the audio to data and data to audio converter of the first aspect of the present invention, similar to Figure

3 and showing an example of a full time converter network user of the first aspect of - 15 - the present invention. In the example shown in Figure 5, the station D 134 telephone or telephones 136 all use the central switch station 108 for all their calls. In the example shown in Figure 5, the station D 134 has a telephone switch 106 connected to a plurality of converters at Dl 138, D2 140 and D3 142. The converters Dl 138, D2 140 and D3 142 all send data to the access server 122 of the D station 134 data transport system 18. So that, every time the telephone 136 is used from station D 134 the call is automatically routed by the telephone switch 106 at the data transport system provider 14 located at station D 134 to the telephone switch 106 at the central switch station 108, making authorization verification unnecessary. The telephone switch 106 at the central switch station 108 then routes the call to the appropriate remote station or uses local or long distance phone lines if an appropriate converter is not available. It is also within the spirit and scope of the present invention to use the audio to data and data to audio converter with another type of telephone switch, a switch/router 144, as seen in Figure 6, which would also contain routing capability so that the converter 10 could be directly connected to the Internet backbone 34. This switch router 144 would then be its own Internet Service Provider, as well as having capabilities of connection through the existing telephone system. Thus, with the use of the switch/router 144, the switch/router 144 would have the ability to gather either voice or data users, and to connect them throughout the world, using either the Internet or the older telephone system. Referring now to Figure 6 of the drawings, there is shown an environmental block diagram of the audio to data and data to audio converter of the first aspect of the present invention used in conjunction with a switch/router 144 which incorporates Internet router technology, as well as telephone technology, and is therefore capable of direct connection to the Internet backbone 34 through trunks 145, as well as direct connection to converter trunks 146 to a traditional phone line system, direct connection to cellular radio systems, telephone instruments, fax machines or modems. It is within the spirit and scope of the present invention, for the audio to data and data to audio converter of the present invention to be the audio/data gateway of the system 148 as shown in Figure 6. In Figure 6, the switch 106, converters 10, access servers 122 and routers 124 depicted in Figures 3, 4 and 5 are efficiently consolidated into a single electronic system which - 16 - functionally replaces both the local data transport system service provider 14 and the local telephone company switch 106, or most commonly the local PBX. In the instance as shown in Figure 6 a plurality of senders 26 use the switch/router 144 to route the telephone call to a plurality of desired recipients. In order for the data to audio and audio to data converter 10 of the first aspect of the present invention to be a practical device, it is necessary that the sender 26 and recipient be able to communicate between any locations available on the world wide telephone system. Therefore, the switch/router 144 in Figure 6 receives a telephone number from the sender 26 and routes the data received from the converter 10 at the sender's data transport system 18 to an appropriate location at any recipient's data transport system.

In the example as shown in Figure 6, it would not be necessary, therefore, for the recipient to have an Internet Service Provider, and all calls would not go through the telephone switch 106 at the central switch station 108 as shown in Figures 3, 4 and 5. In Figure 6, the call is routed by the switch/router 144 to a converter 10 at an appropriate remote location, whereupon the remote data transport system, which can be a Local Access Network of the telephone system at this point, routes the converted data (the voice) to the desired recipient. In Figure 6, then, the converter 10 of the first aspect of the present invention is a circuit 150 positioned on a larger PC card 152, wherein 24 converter circuits 150 are positioned on each PC card 152. Five hundred to one thousand such cards 152 would be part of a central switch station 108, wherein the central switch station 108 would extend audio and data to a local area.

Referring now to Figure 7 of the drawings there is shown an environmental block diagram of the video to data and data to video converter 153 of the first aspect of the present invention wherein a video signal is converted to a data signal. The example, as shown in Figure 7, is illustrative only of another application of the first aspect of the present invention. Figure 7 shows a security television camera 154 positioned at a machine shop area 156 in an industrial plant. In the example of Figure 7 the converter 153 is used to extend the camera's view image to a security desk 158 over an existing ethernet network 160. The machine shop 156 has its own access server 122 for the ethernet 160. The access server 122 in Figure 7 is connected to a printer 162 and a machine controller 164 as typically arranged in such - 17 - an application. The security desk 158 in the example shown in Figure 7, also has its own access server 166. To utilize the camera 154 in this application, a converter 153 is attached to each access server 122 and 166, and the camera 154 is attached to one access server 122, and a monitor 168 is attached to the other access server 166. There is generally a one way transmission of a video signal to a data signal at a remote monitor 168 location, then accomplished in Figure 7. The closed circuit television camera signal is transmitted in a standard video protocol over cable 169 and is converted by the converter 153 into a data stream, the data stream being the same sort of data stream as output in the other applications. The data stream is routed by the router 124 to the monitoring center 170 where the data stream is converted back to the standard video protocol and displayed on a monitor 168. The data stream is transmitted over a data transport system 18 as in the previously described applications. At the recipient 28 remote location, the monitoring center 170, the data stream is converted back to video signals and is transmitted to the recipient 28 as video signals. In the video signal converter 153, as shown in Figure 7, a video interface means 172 replaces the telephone interface means 36 of the previous applications. In other respects, the video to data converter 153 uses the same parts as shown in Figure 1 of the drawings. In Figure 7, the video interface means 172 is attached to a transmission means 40 in the form of a transmitter 52 and a receiving means 42 in the form of a receiver 54, as seen in Figure 1. The video interface means 172 receives video signals and transmits the video signals to the converting means 44 in the form of a converter 153. The converter 153 converts the video signal to a data signal and the transmitter 52 transmits the data signal to a data transport system 18, as seen also in Figure 1. The receiver 54 receives the data signal from the data transport system 18 and the data signal is converted back to video at the recipient's data transport system.

Figure 7 shows the practicality of the video to data converter 153 of the present invention. Without the video to data converter 153 of the first aspect of the present invention it would be necessary to have the security system 174 in a single location because the camera 154 requires that a camera cable 169 be extended from the machine shop area 156 to the security desk 158. With the use of the present converter 153, however, two remote locations anywhere in the world can take - 18 - advantage of the security system 174 because the data signals are transmitted over a data transport system 18, so that a camera cable 169 is not required between the machine shop area 156 and the security desk 158.

Referring now to Figures 8 to 12 in general, and in particular to Figure 8 and Figure 9 of the drawings, there is shown in Figure 8 a block diagram of the real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter or Digital Data Protocol Converter 210 of the second aspect of the present invention. Figure 9 is an environmental block diagram of the digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter of the second aspect of the present invention, in its simplest form, as it is positioned at the access site 212 of a data transport system provider 214, typically the Internet. The converter 210 of the second aspect of the present invention converts digital telephone interface signals received by it from a Tl phone line 216 into a packet data signal in the format used by the data transport system 218. This packet data signal is transmitted over the data transport system 218, to a similar remote location, at the access site 220 of the remote data transport system provider 222. At the remote location, the packet data signal is converted back to a digital telephone interface signal and is transmitted over a Tl phone line 224 at the remote location as a digital telephone interface signal, as seen in Figure 9.

The converter 210 of the second aspect of the present invention generally comprises a two way conversion means having a sender 226 and a recipient 228 as seen in Figure 9. Generally, both the sender 226 and recipient 228 have access to a similar converter 210 one, for the sender 230, positioned at the access site 212 of the data transport system provider 214 and one, for the recipient 232 positioned at the access site 220 of a recipient data transport system provider 222. The converters 230 and 232 work in a mirrored manner for both parties. By positioning the converter 210 of the second aspect of the present invention at the access site 212 of a data transport system provider 214, the converter 210 can transmit its packet data signal using a high quality Tl connection directly to the backbone 234 of the Internet as seen most clearly in Figures 10, 11 and 12. In this way, any delays which may be - 19 - inherent on the Internet due to other numerous local connections, are bypassed, causing the transmission of the packet data signals to be the fastest possible.

While, in typical practice, the converter 210 of the second aspect of the present invention uses the Internet as the data transport system 218 for transmitting packet data signals, it is within the spirit and scope of the second aspect of the present invention to use any type of Local Access Network (LAN), Wide Area Network

(WAN), or wireless distribution system that has sufficient bandwidth to carry a Tl.

In general, as seen most clearly in Figure 9, the converter 210 of the second aspect of the present invention comprises the two way conversion means for converting digital telephone interface signals to packet data signals and packet data signals to digital telephone interface signals for a sender 226 and a recipient 228. Since the converter 210 works in a mirrored manner for both parties, each converter 230 and 232 generally comprises a digital telephone interface means 236, as seen in Figure 8, for linking telephone lines 216 and 224 to the converter 210. It is to be understood that while the following description refers to the digital telephone interface data signal protocol as Tl protocol, this description is illustrative only and it is within the spirit and scope of the invention to convert any digital telephone interface data signal to packet data signal protocol as required by the data transport system, with only minor modifications, which would be obvious to those skilled in the art. The digital telephone interface data signal carrier could be, but is not limited to, any of the following: a frame relay, a Tl, a T2, a T3, El, E3, or OS - XX signal using SF or ESF framing and B8ZS or NRZ coding.

Tl protocol uses a type of multiplexing called Time Division Multiplexing wherein two or more channels of information (or telephone conversation) are transmitted over the same link by allocating a different time interval for the transmission of each channel. As the channels take turns using the link, a periodic synchronizing signal or distinguishing identifier is usually used so that the receiver can distinguish which of the channels it is receiving at any given time. A transmitted Tl signal, therefore, consists of a starting sequence, followed by 24 channels of telephone conversation. These 24 channels of telephone conversation are multiplexed so that different channels have different pieces of a telephone conversation at any - 20 - given time. Each of the 24 channels has 8 bits which encode the amplitude of the voice at the particular time that a telephone conversation is transmitted on that channel. This process is repeated 8,000 times per second, which means that each channel in the Tl is carrying voice at 64 kilobits per second. In the preferred embodiment of the second aspect of the present invention, the digital telephone interface means 236 uses one channel of a Tl interface to transmit digital telephone interface signals from the telephone 238 to the converter 210 of the second aspect of the present invention. The digital telephone interface means 236 is attached to a transmission means 240 and a receiving means 242, as seen most clearly in Figure 8, the digital telephone interface means 236 receiving digital telephone interface signals and transmitting the digital telephone interface signals to a converting means 244, as seen also in Figure 8. The converter 210 of the second aspect of the present invention also generally comprises a real-time converting means 244 which converts the digital telephone interface signal received from the digital telephone interface means 236 to a packet data signal or converts a packet data signal received from the data transport system 218, as seen in Figure 9, to a digital telephone interface signal. The converting means 244 is attached at one end 246 to the transmission means 240 and at the other end 248 to the receiving means 242. The transmission means 240 of the second aspect of the present invention transmits packet data signals to the data transport system 218 and the receiving means 242 receives packet data signals from the data transport system 218.

In the example shown in Figure 9, the sender 226 is connected by direct Tl connection 250 to the sender's data transport system provider 214 and the sender's switch 252 is located locally or collocated with the sender's data transport system provider 214. The recipient 228 is connected to the recipient data transport system provider 222 through a local telephone network 254 having a dedicated Tl circuit 256 for this purpose. The Tl circuit 256 represents a large user because of the traffic which it carries and because of the expense of the telephone switch 258 to which it is attached. It is anticipated that most users will use a data transport system provider 214 installed by the owner of the telephone switch 252, specifically to carry voice traffic from the telephone switch 252 to the data transport system 218, in a direct - 21 - connection, as shown at the sender 226 side of Figure 9. It is also within the spirit and scope of the invention that a user having a smaller, private switch 259 would lease a Tl circuit 256 through a local telephone network 254 as shown in the recipient 228 side of Figure 9. The converter 210 of the second aspect of the present invention works with either type of connection and is independent of any connection restrictions. The converter 210 of the second aspect of the present invention also works independently of any type of signal sent or received and also converts fax 260 or modem 261 signals to be transmitted over a data transport system 218 to or from a telephone switch 252. More specifically, in the simplest form of the second aspect of the present invention, as seen most clearly in Figure 9, the sender 226 transmits his voice to a switch 252 which can be a local switch 259, as seen in Figures 10 and 11, or a major switch point 262, as seen in Figures 10 and 11. The switch 252 translates the sender's voice signal to a digital telephone interface signal, as described in greater detail with reference to Figures 10, 11 and 12. The sender 226 thereby transmits a digital telephone interface signal using the digital telephone interface means 236. The sender's data transport system provider 214 delivers the call to the converter 210 of the second aspect of the present invention at the access site 212 of the data transport system service provider 214, most typically the Internet Service Provider. At the data transport system provider 214, when the call is delivered, the converter 230 of the second aspect of the present invention converts the digital telephone interface signal to a packet data signal, and routes the packet data signal to a converter 232 positioned at the access site 220 of the recipient data transport system provider 222. When the digital telephone interface signal is first received at the converter 230 of the sender's data transport system provider 214, the transmission means 240 in the form of a transmitter 263 transmits the digital telephone interface signal to a receiving means 242 in the form of a receiver 264, as seen most clearly in Figure 8. The transmitter 263 and receiver 264 are both attached to the digital telephone interface means 236 which links Tl telephone lines 216 and 224 to the converter 210. From the digital telephone interface means 236, the sender's digital telephone interface signal goes to a real-time converting means 244 where the sender's digital telephone interface signal - 22 - is converted to a packet data signal. From the converting means 244, the now converted packet data signal is sent over the data transport system 218 to the converter 232 at the recipient's data transport system provider 222. The converter 232 at the recipient data transport system provider 222 converts the packet data signal back to a digital telephone interface signal. The recipient 228 digital telephone interface 236, as seen as Figure 8, routes the digital telephone interface signal through the recipient telephone network 254 to the recipient 228 switch 258 which converts the digital telephone interface signal back into the sender's voice signal and routes the sender's voice to the ultimate destination. At this point, after the recipient 228 has received the sender's voice, the recipient 228 responds and thereby now becomes the sender 226, whereby the process is repeated.

In particular, the sender 226 transmits a digital telephone interface signal using the transmission means 240 of the converter 210, in the form of a transmitter 263, as seen in Figure 8. The transmitter 263 transmits the digital telephone interface signal to a receiving means 242 in the form of a receiver 264. Attached to both the transmitter 263 and receiver 264 is the digital telephone interface means 236 for linking Tl telephone lines 216 and 224 to the converter 210. From the digital telephone interface 236, the sender's digital telephone interface signal goes to the realtime converting means 244 where the sender's digital telephone interface signal is converted to a packet data signal. The packet data signal is transmitted over the data transport system 218 (typically the Internet) and is received by the recipient 228 at the recipient's converter 232 as a packet data signal. The packet data signal goes to the converter 232 of the recipient 228, where it is converted to a digital telephone interface signal. The digital telephone interface signal goes from the converting means 244 to the recipient's digital telephone interface 266 whereupon it is transmitted to the recipient 228 as a digital telephone interface signal. When the recipient 228 answers, the reverse process takes place, all in real-time so that there are no uncomfortable gaps between sending and receiving a digital telephone interface signal. Each of the converters 230 and 232 then, the sender's converter 230 and the recipient's converter 232 act as alternating senders and recipients. Each converter 230 and 232 is the same, just positioned at the access sites 212 and 220 for different data - 23 - transport system providers 214 and 222. So, each converter 230 and 232, has a sender portion 268, when it acts as a sender 226 and a recipient portion 270 when it acts as a recipient 228, as seen in Figure 8.

In Figure 8, at the sender portion 268 of the converter 210, a buffer 272 converts a + and - 1.5 volt DSX level signal, which is the level of Tl used to interconnect Tl within a central office or similar telephone industry facility, to a 5 volt logic signal used by the circuit 274 of the present digital telephone interface converter 210. A sync detector 276 uses the frequency of the transmitted signal to synchronize the transmit clock 278. A transmit start detector 280 identifies the start sequence of each 24 channel group and controls a transmit divider circuit and pulse generator 282. The divider circuit 282 divides the clock pulses from the transmit clock 278 and combines them to produce all time-controlled pulses which are used by the transmitter 263. The transmit divider circuit 282 controls the gate 284 which blocks a channel group in the Tl stream at controlled intervals. The transmit divider circuit 282 also controls the read out of the packet message header from the Nonvolatile Random Access Memory, NVRAM 286. The header is permanently entered into the NVRAM 286 and is repetitively inserted into the space created in the Tl message by the gate 284. The output of the gate 284 is a stream of packets in a format acceptable to the data transport system 218 and is in a format suitable to be sent to a normal data transmission port 288 to transfer packet data signals across the data transport system 218, as seen in Figure 9. The packet data signal output from the gate 284 is addressed to the corresponding digital telephone interface converter 210 positioned at the recipient portion 270 of the connection. A transmit buffer 290 converts the 5 volt logic signals to the signal levels appropriate to the data transport system 218.

At the recipient portion 270 of the converter 210 there is a receive buffer 292 which converts the signal levels of the data transport system 218 back to the 5 volt logic levels used by the circuit 274 of the converter 210. The recipient portion 270 of the converter 210 has a separate receive clock 294 which is synchronized by the receive signal. The receive clock 294 drives the receive divider circuit and pulse generator 296. A receive start detector 298 identifies the start sequence of each 24 - 24 - channel group and controls the receive divider circuit 296. The receive divider circuit 296 controls the receive gate 300, which blocks the packet header from the receiver 264. The receive divider circuit 296 also controls a First-In-First-Out register 302 which repeats the last frame received, into the receive Tl stream to fill the space left by the header information which has been removed. The output of the receiver 264 is a continuous 64 Kilobit Tl stream which has an actual voice conversion rate of 32 Kilobits, with an occasional channel interval having 32 Kilobits. The 32 Kilobits has a negligible effect on the audio heard by the user, since 32 Kilobits voice is quite useable and is in fact commonly used in international calling. A buffer 304 converts the 5 volt logic signals received from the receive gate 300 back into + and - 1.5 volt

DSX signals used to interconnect different Tl devices.

Referring now to Figure 10 of the drawings there is shown an environmental block diagram of a typical application of the digital telephone interface signal to packet data signal converter of the second aspect of the present invention. Figure 10 illustrates a distributed switch network 306 wherein connections can be made between senders 226 and recipients 228 through local telephone switches 259 or major telephone switch points 262. Connections made between senders 226 and recipients 228 are controlled through distributed switches 306 at the data transport system provider 214. Calls can be routed through the local switch 259 if the destination is directly available or can be routed through a major switch point 262 if the destination is indirectly available. In Figure 10 a connection is made between a sender 226 and recipient 228 through a local telephone switch 259, such as a Private Branch Exchange or PBX, as shown separately also in Figure 11. In the example of Figures 10 and 11, a sender 226 located locally to the converter A 308 contacts a recipient 228 located at converter C 310. The sender 226 calls his local converter 308, through a local telephone switch 259. The local telephone switch 259 converts a voice signal from the sender 226 to a digital telephone interface signal. In the example shown in Figures 10 and 11, since either parties digital telephone interface protocol is European, the digital telephone interface signal that is transmitted to the converter is El . The sender's digital telephone interface signal is converted to a packet data signal at converter A 308. From converter A 308 the packet data signal is transmitted over - 25 - an Ethernet 312 in Figures 10 and 11 to a router 314. The router 314 routes the packet data signal from the Ethernet 312 to the data transport system 218 over an E3 signal line 316 where it is sent to a router 314 at the recipient's location 318. The router 314 at the recipient's location 318 sends the packet data signal over an Ethernet 312 to a converter C 310 at the recipient's location 318. The converter C 310 now converts the packet data signal to a digital telephone interface protocol that is appropriate to the recipient 228, and a local telephone switch 259 receives the digital telephone interface signals which are translated at the local telephone switch 259 back to the voice of the sender 226. In Figure 10 also and separately in Figure 12 there is shown a connection made between a sender 226 and recipient 228 through a major telephone switch point 262, such as a Public Service Telephone Network or PSTN. In the example of Figures 10 and 12, a sender 226 located locally to converter B 320 contacts a recipient 228 located at converter D 322. The sender 226 calls his local converter 322 through a major telephone switch point 262. The major telephone switch point

262 converts a voice signal from the sender 226 to a digital telephone interface signal. In the example shown in Figures 10 and 12, since either parties digital telephone interface protocol is American, the digital telephone interface signal that is transmitted to the converter 320 is Tl over a Tl signal line 324. El signal lines 326 are also available for international callers. The sender's digital telephone interface signal is converted to a packet data signal at converter B 320. From converter B 320 the packet data signal is transmitted over an Ethernet 312 to a sender's router 314. The sender's router 314 routes the packet data signal from the Ethernet 312 to the data transport system 218 first over a T3 signal line 328 and from the data transport system 218 over an OS3 signal line 330 where it is sent to a recipient's router 314 at the recipient's location 318. The router 314 at the recipient's location 318 sends the packet data signal over an Ethernet 312 to a converter D 322 at the recipient's location 318. The converter D 322 now converts the packet data signal to a digital telephone interface protocol that is appropriate to the recipient 228, and a local telephone switch 259 receives the digital telephone interface signals which are translated at the local telephone switch 59 back to the voice of the sender 226. - 26 -

From the foregoing it is apparent that numerous changes to circuitry, arrangements of parts and hardware could easily be incorporated within the spirit and scope of the invention. The present invention can also be used with numerous types of interfacing equipment within the spirit and scope of the invention. Therefore the preferred embodiments above have been given by way of illustration only and are not intended to limit the scope of the invention.

Claims

- 27 -CLAIMS

1. A real-time audio to data and data to audio converter for interfacing audio signals with a data transport system, the audio to data and data to audio converter comprising: a) a telephone interface means for linking telephone lines to the converter, the telephone interface means being attached to a transmission means and a receiving means, the telephone interface means receiving audio signals from and transmitting the audio signals to a converting means; b) a real-time converting means for converting the audio signal to a data signal or a data signal to an audio signal, the converting means being attached at one end to a transmission means and at the other end to a receiving means; c) a transmission means for transmitting the data signal to a data transport system; d) a receiving means for receiving the data signal from the data transport system; and whereby an audio signal is received and converted in real-time to a data signal which in turn is received as a data signal and converted in real time to an audio signal.

2. A real-time audio to data and data to audio converter as claimed in claim 1, further comprising: a plurality of the converters in a network; a central station at the data transport system, the central station having at least one converter.

3. A real-time audio to data and data to audio converter as claimed in claim 2, further comprising: telephone switching means for switching data between a converter at the central station and other converters in the network. - 28 -

4. A real-time audio to data and data to audio converter as claimed in any preceding claim, further comprising: a switch/routing means for routing the audio signals to a desired remote location.

5. A real-time audio to data and data to audio converter as claimed in any preceding claim, further comprising: an amplifying means for converting a received balanced telephone audio signal into an unbalanced signal.

6. A real-time audio to data and data to audio converter as claimed in any preceding claim, further comprising: a modulating/demodulating means for sampling an input audio signal, dividing the signal and outputting a bit stream.

7. A real-time audio to data and data to audio converter as claimed in any preceding claim, further comprising: a timing means for synchronizing the converter, the timing means having high frequency signals.

8. A real-time audio to data and data to audio converter as claimed in claim 6, further comprising: a gating means for removing undesirable spikes in the bit pattern and producing a smooth ASCII bit stream.

9. A real-time audio to data and data to audio converter as claimed in claim 7, further comprising: a dividing means for dividing the high frequency signals of the timing means to lower frequency signals output as a clocking pulse. - 29 -

10. A real-time audio to data and data to audio converter as claimed in any preceding claim, wherein: the telephone interface means uses a four wire E and M trunk to transmit audio signals to the converting means.

11. A real-time audio to data and data to audio converter as claimed in claim 6, wherein: the modulator/demodulator is a delta modulator.

12. A real-time audio to data and data to audio converter as claimed in any one of claims 1 to 9, wherein: the telephone interface means uses a two wire E and M trunk to transmit audio signals to the converting means.

13. A real-time video to data and data to video converter for interfacing video signals with a data transport system, the video to data and data to video converter comprising: a) a video interface means for linking video lines to the converter, the video interface means being attached to a transmission means and a receiving means, the video interface means receiving video signals and transmitting the video signals to a converting means; b) a real-time converting means for converting the video signal to a data signal or a data signal to a video signal, the converting means being attached at one end to a transmission means and at the other end to a receiving means; c) a transmission means for transmitting a data signal to a data transport system; d) a receiving means for receiving the data signal from the data transport system; and whereby a video signal is received and converted in real-time to a data signal which in turn is received as a data signal and converted in real-time to a video signal. - 30 -

14. A method of converting audio to data and data to audio in real-time and for interfacing audio signals with a data transport system using a converter, comprising the steps of: a) providing a telephone interface means for linking telephone lines to the converter, the telephone interface means receiving audio signals and transmitting the audio signals to a converting means; b) providing a real-time converting means for converting the audio signal to a data signal or a data signal to an audio signal, the converting means being attached at one end to a transmission means and at the other end to a receiving means; c) providing a transmission means for transmitting a data signal to a data transport system; d) providing a receiving means for receiving the data signal from the data transport system; and whereby an audio signal is received and converted in real-time to a data signal which in turn is received as a data signal and converted in real-time to an audio signal.

15. A method of converting audio to data and data to audio signals as claimed in claim 14, further comprising: providing a plurality of the converters in a network; providing a central station at the data transport system, the central station having at least one converter.

16. A method of converting audio to data and data to audio signals as claimed in claim 15, further comprising: providing a switching means for switching data between a converter at the central station and other converters in the network.

17. A method of converting audio to data and data to audio signals as claimed in any one of claims 14 to 16, further comprising: - 31 - providing a switch/routing means for routing the audio signals to a desired remote location.

18. A method of converting audio to data and data to audio signals as claimed in any one of claims 14 to 17, further comprising: providing an amplifying means for converting a received balanced telephone audio signal into an unbalanced signal.

19. A method of converting audio to data and data to audio signals as claimed in any one of claims 14 to 18, further comprising: providing a modulating/demodulating means for sampling an input audio signal, dividing the signal and outputting a bit stream.

20. A method of converting audio to data and data to audio signals as claimed in any one of claims 14 to 19, further comprising: providing a timing means for synchronizing the converter, the timing means having high frequency signals.

21. A real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface carrier signal converter for a data transport system, the converter comprising: a) a digital telephone interface means for linking digital telephone lines to the converter, the digital telephone interface means receiving digital telephone interface carrier signals from and transmitting the digital telephone interface carrier signals to a converting means; b) a real-time converting means for converting the digital telephone interface carrier signal to a packet data signal or a packet data signal to a digital telephone interface carrier signal; c) a transmission means for transmitting the digital telephone interface carrier signal to a data transport system; - 32 - d) a receiving means for receiving the digital telephone interface carrier signal from the data transport system. whereby a digital telephone interface carrier signal is received and converted in real-time to a packet data signal which in turn is received as a packet data signal and converted in real-time to a digital telephone interface carrier signal.

22. A real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter for a data transport system, the converter comprising: a) a digital telephone interface means for linking digital telephone lines to the converter, the digital telephone interface means receiving digital telephone interface signals from and transmitting the digital telephone interface signals to a converting means; b) a real-time converting means for converting the digital telephone interface signal to a packet data signal or a packet data signal to a digital telephone interface signal, the real-time converting means being connected to the data transport system; c) a transmission means for transmitting the digital telephone interface signal to the data transport system, the transmission means being connected to the digital telephone interface means; d) a receiving means for receiving the digital telephone interface signal from the data transport system, the receiving means being connected to the digital telephone interface means; and whereby a digital telephone interface carrier signal is received and converted in real-time to a packet data signal which in turn is received as a packet data signal and converted in real-time to a digital telephone interface signal.

23. A real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter as claimed in claim 22, wherein the real-time converting means is connected to the data transport system by means of a frame relay. - 33 -

24. A real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter as claimed in claim 22 or

23, wherein the real-time converting means is connected to the data transport system by means of fiber optic cable.

25. A real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter as claimed in claims 22 to

24, wherein the digital telephone interface signal is audio.

26. A real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter as claimed in claim 22 or 23, wherein the digital interface signal is data.

27. A real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter as claimed in claim 22 or 23, wherein the digital telephone interface signal is video.

28. A real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter as claimed in any one of claims 22 to 27, further comprising: a) a plurality of the converters in a network; b) a central station at the data transport system, the central station having at least one converter.

29. A real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter as claimed in claim 28, further comprising: a) telephone switching means for switching data between a converter at the central station and other converters in the network. - 34 -

30. A real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal as claimed in any one of claims 22 to 29, further comprising: a) a switch/routing means for routing the audio signals to a desired remote location.

31. A real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter as claimed in any one of claims 22 to 30, wherein the digital telephone interface signal is any one of a plurality of predetermined digital telephone protocols.

32. A real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter as claimed in any one of claims 22 to 30, wherein the digital telephone interface signal is a plurality of predetermined digital telephone protocols.

33. A real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter as claimed in claim 23, wherein the digital telephone protocol is American.

34. A real-time digital telephone interface signal to packet data signal and packet data signal to digital telephone interface signal converter as claimed in claim 23, wherein the digital telephone protocol is European.

35. A method of converting digital telephone interface signals to packet data signals and packet data signals to digital telephone interface signals in real time and for interfacing digital telephone signals with a data transport system using a converter, comprising the steps of: a) providing a digital telephone interface means for linking digital telephone lines to the converter, the digital telephone interface means receiving digital - 35 - telephone interface signals from and transmitting the digital telephone interface signals to a converting means; b) providing a real-time converting means for converting the digital telephone interface signal to a packet data signal or a packet data signal to a digital telephone interface signal, the real-time converting means being connected to the data transport system; c) providing a transmission means for transmitting the digital telephone interface signal to the data transport system, the transmission means being connected to the digital telephone interface means; d) providing a receiving means for receiving the digital telephone interface signal from the data transport system, the receiving means being connected to the digital telephone interface means; and whereby a digital telephone interface signal is received and converted in realtime to a packet data signal which in turn is received as a packet data signal and converted in real-time to a digital telephone interface signal.