Abstract:
An Internet phone provides standard voice and Internet audio functions using the familiar Plain Old Telephone System platform. Internet audio connections are initiated using an access button on the base of the telephone. A phone keypad and alphanumeric keyboard provide both DTMF dialing and Internet message handling functions. A speaker is provides or the hand set can be used to send and receive Internet compressed audio messages over the Public Switched Telephone System via the user&#39;s Internet access provider. The user selects a recipient from a stored address list or creates a new recipient using the alphanumeric keyboard. Once the call is established, a user at either end speaks directly into the phone receiver wherein his voice signal is digitized into a voice file that is stored and transferred to the user at the other end. The Internet phone an integrated display and display electronics which decode incoming messages. A ROM based program inside the phone decodes the address portion of an incoming Internet message and displays it on the screen identifying the identity of the the caller.

Description:
TECHNICAL FIELD 
     The invention relates in general to a device for receiving and transmitting audio signals via the Public Switched Telephone Network and, more particularly, to a telephone hand set with combined voice and Internet compressed audio signal telecommunications functions. 
     BACKGROUND OF THE INVENTION 
     The Internet has become the information “superhighway” of choice for an ever increasing number of individuals who have turned to it as an inexpensive and effective way of exchanging electronic data and information. While often thought of as a world-wide network, in reality the Internet is comprised of numerous different networks throughout the world which are linked together using a common routing protocol known as the Internet Protocol (IP). This architecture provides widespread access from an unspecified number of terminals or other dial-up equipment around the world. 
     Individual users, groups and other entities are identified on the Internet by a unique address conforming to the IP. A local access hub provides users with an entry way into the Internet network and acts as the exchange point for both incoming and outgoing data. The data flows along virtual channels consisting of a plurality of gateways, data routers and other physical equipment which work together to form a signal path from message origin to its intended destination. Since a point-to-point connection is never established, the costs to the user are limited to those charged by the local access provider and/or a nominal periodic access fee. 
     The low cost associated with Internet access and use has spurred the development of audio applications that allow users to receive and transmit compressed Internet voice messages across the Internet. Typically, a user at one end of the connection speaks into a microphone attached to a Personal Computer (“PC”). The microphone carries the audio voice signal to a processor board in the PC which digitizes the signal and creates a digital voice file. The voice file is then typically compressed and transferred to a selected recipient at a distant point on the Internet. Once received, the voice file is decompressed and converted via digital signal processing to an audible signal intelligible to the human ear. 
     The typical Internet audio set includes a PC, modem, Internet access software, file compression software and operating system. The user executes the software off the PC&#39;s hard disk or floppy drive and the modem provides the hardware communications link with the local Internet access provider. This operation involves turning the PC ON, executing the software, gaining access to the Internet, recording the voice file and transmitting its intended recipient. At the receiving end, the process is duplicated in almost exact fashion but in reverse. 
     While such applications are available and useful for inexpensive long distance use, the average long distance caller may not have access to a computer or may not be versed in the installation, operation and use of computer executed software. These prior art audio sets have not yet replaced the Plain Old Telephone System (“POTS”) on a widespread basis. The POTS, on the other hand, has widespread appeal and provides intuitive operation. 
     Thus, a device that combines the simplicity of operation of the POTS with low cost audio access to the Internet would provide numerous advantages over prior Internet audio sets. 
     SUMMARY OF THE INVENTION 
     It has been found the prior audio communications systems for the Internet are cumbersome to use and do not provide the functionality long distance callers have come to expect from their familiar telephone set. 
     As such, it is a primary object of the present invention to provide a device that integrates the functionality of the POTS with dial-up access to the Internet. In this regard, a device which supports Internet audio protocol standards G.723, G.725 and G.729 and standard analog audio protocol G.711 for all phones is provided. 
     In one embodiment, the present invention defines an Internet compatible phone with an integrated modem set that is operated by the user via an extended keypad with alphanumeric entry keys and function keys. An Internet dial button on the front face of the phone operates the modem functions inside the telephone providing a switch between normal DTMF voice communications and Internet compressed voice signal functions using available Internet service providers. The phone has an integrated display screen and display electronics that renders visual call progress information to the user as well as other communications indicators and related information about the current Internet connection. 
     Another object of the present invention is to provide a device that is similar to the POTS. In this regard, a true telephone phone set, one that doesn&#39;t require to be booted up to run a standard PC, is provided with a phone keypad for DTMF dialing similar to a regular phone. The set includes a hand set with a receiver and mouth piece and can be used to make voice connections via the PSTN and compressed audio using the Internet protocol. 
     All Internet access functions are transparent to the user while in normal voice mode operation. An Internet access button is depressed by the user to activate access to the Internet using a preprogrammed access number and other access parameters stored in an erasable memory circuit. The user selects a recipient from a stored address list or creates a new recipient using the alphanumeric keyboard. Once the call is established, a user at either end speaks directly into a microphone on the base of the device wherein his voice signal is digitized into a voice file that is stored, compressed and routed to the user at the other end. 
     Yet another object of the present invention is to provide a visual interface to the information content of an audio message transferred over the Internet. To achieve this, a display screen display driver are provided inside the base of the phone. A digital signal processor inside the phone decodes the incoming message and strips the address portion of the message. The address is displayed at the phone screen display identifying the identity of the the caller. 
     For a more complete understanding of the present invention, including its features and advantages, reference is now made to the following detailed description, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIG. 1 illustrates a prior art Internet audio set; 
     FIG. 2 is a top side view of the Internet phone according to the present invention; and 
     FIG. 3 is a detailed circuit diagram for the Internet phone according to the invention. 
     Corresponding numerals refer to corresponding parts in the figures unless otherwise indicated. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In FIG. 1, a prior art Internet audio set is shown and denoted generally as  10 . Internet set  10  includes a personal computer (PC)  15  with a keyboard  17  and monitor  19 . Inside the PC  15  are a plurality of application programs which are stored generally on hard disk  21 . A microphone  23  is communicably attached to the PC  15  via cable  25  which carries audio signals from the user to a processing board  27 . The processing board  27  digitizes the voice signal and creates a voice file which can be stored on hard disk  21  prior to transmission. 
     In operation, a user gains access to the Internet via an application program stored on hard disk  21 . The manner and steps involved in such a process vary depending on the type of PC  15  and software program used. A plurality of Internet access providers may be used for this purpose wherein the user subscribes to the provider and uses a modem  29  to establish the communications link between the user and the provider. In general, the user executes a voice recording program stored on hard disk  21 . The voice recording program accepts an audio signal input via the microphone  23  and operates the processing board  27 . Other PC  15  functions can be operated using keyboard  17 . 
     The processing board  27  receives the audio analog signal from the user via the microphone  23  and cable  25  and creates a corresponding digital file using on-board digital signal processing. The techniques and methods of digital signal processing are well known in the industry and by those skilled in the art. 
     Next, the user selects an intended recipient from the application program interface and the digital audio file is sent to the chosen recipient via the modem  29 . As shown, the modem  29  is communicably attached via cable  31  to the Public Switched Telephone Network (“PSTN”)  33 . Call and transmission progress information are displayed on monitor  19  depending on the status of the connection. For example, the monitor  19  can display the recipient, connection status and latest activity. Other information can be displayed depending on the software program used and the functionality of the Internet audio set  10 . 
     The audio set  10  can also be used to receive audio files using the PSTN  33  connection and modem  29 . In general, a transmitting party at a distant location uses the address of the audio set  10  to transmit digitized audio messages over the Internet in the manner described above. The audio set  10 , and more specifically processing board  27 , receives the incoming audio signal and transforms it to its corresponding analog equivalent. The analog audio signal is broadcast over the PC speaker  35  which is controlled by the audio application software. 
     Thus, the prior art audio set  10  provides a mechanism for voice communications over the Internet using the above described process and hardware shown in FIG.  1 . Variations of set  10  are also available using similar methods of operation and allowing users a plurality of similar functionality. Such systems, however, are substantially similar in that they depend on use of a PC  15 , application programs, and other similar equipment as shown in FIG.  1 . 
     Turning now to FIG. 2, the Internet phone  50  of the present invention is shown. Internet phone  50  has many of the features of a Plain Old Telephone System (“POTS”) including hand set  55  which has an ear piece  58  and a mouth piece  56  for hearing and speaking, respectively. The hand set  55  can be used to transmit and receive the pure analog audio signals, which are digitized and processed for transmission on the network. 
     As shown, the hand set  55  is communicably attached via cable  57  to base  59 . The base  59  houses the various telecommunications devices as herein described and as can be appreciated by those skilled in the art. 
     Accessible from on the top  61  of base  59  are various keys and input devices which control the operation and functionality of the Internet phone  50 . An alphanumeric keyboard  63  provides a QWERTY type interface from which the user can enter alphabetic and numeric entries and messages to be included in the Internet message stream. The keyboard  63  is similar to the input device of a typical desktop computer. 
     In one embodiment, a numeric keypad  65  is shown and provided to give the identical Dual Tone Multifrequency (“DTMF”) push button operation of a POTS. Thus, in operation a user lifts the hand set  55  and dials into the PSTN using keypad  65  to make normal voice DTMF telephone calls. In this way, POTS functionality is provided by the Internet phone  50  according to one embodiment. 
     A microphone  67  is provided on the base  59  and used to receive and transmit audible signals from and to the user. The microphone  67  is controlled by internal electronics inside the base  59  (see FIG. 3) and provides audible incoming and outgoing audio signals. In the alternative, audio signals can be received and transmitted via the hand set  55  using the ear piece (not shown) and mouth piece (not shown), respectively. 
     According to one embodiment, an Internet access button  69  is provided on the base  59  and used to switch between normal DTMF voice calls and Internet dial-up operations. In this way, access button  69  can be used to initiate an Internet connection using the internal modem set (not shown in FIG. 2) without interrupting the present DTMF initiated switched voice connection. 
     An integrated display screen  71  is provided to give the user visual information about the current Internet connection as well as other connection/status information. For example, the display screen  71  can show the current callee, a stored list of available callees including their Internet addresses, the identity of the transmitting party and his Internet address, a list of the most currently received or transmitted messages or other similar information according to the preprogrammed functionality of the Internet phone  50 . 
     As such, it should be understood that a wide range of information may be displayed on the display screen  71 . In the preferred embodiment, display screen  71  is a liquid crystal display of the type commonly found in industry. 
     The Internet phone  50  connects to the PSTN via jacks  80  and  82  which provide dual line access to the PSTN via outlets  84 . This configuration provides concurrent DTMF and Internet connections. In an alternative embodiment, single line access is provided wherein the Internet phone  50  is used as either a DTMF voice or Internet audio set per single session. In one embodiment, the connection mode is selected by the user with button  69 . 
     A connection  88  to a computer  90  is also provided to permit the transfer of Internet formatted messages between the Internet phone  50  and the computer  90 . An RS 232  jack  86  is the preferred interface between the Internet phone  50  and the computer  90  for serial data transfers although other connection protocols, such as parallel bus, may be used. 
     In FIG. 3, a circuit diagram for the Internet phone  50  is shown and denoted generally as  100 . Circuit diagram  100  is one possible arrangement of components. Those skilled in the art will appreciate that other configurations may be employed. The components are maintained inside the base  59  and assembled during manufacturing by well known means such as on a printed circuit board. Standard off-the-shelf components which are readily available in the market place may be used for most devices and, as such, no particular or specific device is necessary to achieve the objects of the invention as herein described. 
     As shown, a telephone line interface  102  serves as a connection between the PSTN and the Internet phone  50 . A supervisory circuit  104  provides the Onhook/Offhook mechanism between the interface  102  and the PSTN and is operated by the optical isolator  106 . The analog signal is received superimposed on a DC level carrier which is isolated via the transformer primary  108 . 
     The analog signal is dropped across the secondary portion  110  of the line transformer where it is load balanced and received by the modem data pump  112 . In essence, the telephone line interface  102 , isolator circuit  106 , and transformer  108 ,  110  form a direct access arrangement of the type well known by those skilled in the art. It should be understood, however, that other similar configurations and methods of interfacing the modem data pump  112  to the PSTN can be used. 
     The modem data pump  112  is controlled by CPU controller  116  via path  114 . In various embodiments, the data pump  112  supports a plurality of data transmission, compression and error correction protocols including, without limitation, V.34, V.32, V.22, V.42 LAPM, MNP2-5 and still others. Such protocols are well known by those skilled in the art. 
     An audio compression circuit  118  is also shown coupled to the data pump  114  via path  117  which supports known Internet audio standard protocols such as G.723, G.725 and G.729. The compression circuit  118  also supports G.711 which is the standard audio protocol for all POTS. As shown, circuit  118  is coupled to the primary  108  via coil  120  allowing bidirectional audio transmission through and from the PSTN. 
     A speaker  130  and microphone  132  are provided to provide the user with an audible signal output and voice input, respectively. During an Internet audio session, the optical isolator circuit  106  enables the microphone  132  portion of the circuit  100  via path  107 . Signals from the microphone  132  are received by the compression circuit  118  and transferred to the data pump  112  for signal processing and transmission on the PSTN to its intended recipient using well known modulation/demodulation techniques. 
     Likewise, signals received from the PSTN via the data pump  112  are deencoded by the compression circuit  118  and delivered to the user via the speaker  130  as an audible output signal. The corresponding multiplexing logic (M 1  and M 2 ) are shown arranged in FIG. 3 per one embodiment. 
     DTMF functionality is supported via transceiver circuit  140  and phone keypad  142 . This arrangement gives the Internet phone  50  DTMF dial-up capabilities for normal voice connections on a switched circuit basis and alphanumeric entry during Internet sessions. The phone keypad  142  combines the inputs from the keyboard  63  and keypad  65  shown in FIG.  2  and is coupled to the controller  116  via pathway  144 . The controller  116  is programmed to select the correct input device depending on the type of connection, either standard DTMF or Internet Protocol. 
     The preferred display screen  71  is a Liquid Crystal Display of the type known to those skilled in the art and is controlled by display driver circuit  150  and controller  116  via path  144 . Other system components include memory circuits  155  and  157 , which, provide the microprocessor with permanent and erasable memory area segments for performing the various functions herein described. Such functions include power-up sequences, system checks and other standard system verification processes as well as call connect functions, user features and still others. 
     One feature of the Internet phone is the ability to connect to existing Internet access provider services without requiring extensive software knowledge by the user. In one embodiment, access parameters are maintained on the erasable and programmable memory circuit  157 . The access parameters control how the phone  50  connects to the user&#39;s Internet access provider. 
     In one embodiment, the user is prompted to enter a plurality of access parameters such as the provider&#39;s telephone number, IP address, domain name server address, user name, password and other similar parameters during initial setup. The Internet access setup program is stored internally by the controller circuit  116  and input by the user is accomplished using the phone keypad  142 . These parameters are stored in memory circuit  157  and used for connection to the provider once the Internet access button  69  is depressed. 
     The controller  116 , as shown, initiates the connection using the parameters stored in the memory circuit  157 . In this regard, a setup program can be internally maintained and executed upon initial use or setup by the user. 
     Also, the erasable memory circuit  157  can be used to store a list of common recipients by their Internet addresses. Alternatively, the user creates new recipients for further use and retrieval using the alphanumeric keyboard  63  of the phone keypad  142 . 
     Other system components are illustrated in FIG. 3 such as watch dog timer circuit  160 , audio speaker phone  162  and ringer adjustment circuit  165  all of which are well understood by those skilled in the art. 
     In summary, the present invention comprises a device that combines DTMF voice functions with an Internet audio set into an integrated POTS platform which is familiar to everyday telephone users. The outward appearance of the device is illustrated in FIG. 2 while the internal arrangement of device components appears in the circuit diagram of FIG.  3 . 
     While this invention has been described and referenced to illustrative embodiments, the description is not intended to be construed in a limiting sense. Various modifications and combinations of illustrative embodiments as well as other embodiments and inventions will become apparent to those persons skilled in the art upon reference or description. It is, therefore, intended that the pendent claims encompass any such modifications or embodiments.