Abstract:
A telephony apparatus ( 10 ) for communication over a network ( 300 ) includes a user interface module for collecting audio input and broadcasting audio signals, a converter ( 110 ) for converting digital signals into audio signals, an Internet protocol (IP) module ( 130 ) for packing digital signals into IP packets, a network interface module ( 140 ) connected with the IP module for providing a communication interface between the telephony apparatus and the network, and a protocol/signaling controlling module ( 150 ) connected with the converter and the IP module for exchanging communication protocols/signalings. The converter is connected with the user interface module, and also converts audio signals into digital signals. The IP module also unpacks IP packets into digital signals. A related method for telephonic communication over a network between a calling telephony apparatus and a called telephony apparatus is also provided.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a telephonic communication system, and more particularly to an apparatus and method for computer network telephony.  
           [0003]    2. Description of Related Art  
           [0004]    Conventional network telephone communication is developed on the basis of an IP (Internet Protocol) network. A conventional network telephone system employs a normal fixed-line type of telephone set as a terminal. A service gateway converts audio signals transmitted from the normal telephone into IP packets, which are then transmitted over the IP network. Since the IP packets need not monopolize a particular communication channel, the cost of a long-distance telephone call using the network telephone system is greatly reduced.  
           [0005]    However, the service gateway is generally provided by a telecommunication service provider. The telecommunication service provider charges the subscribers for the service gateway. As a result, the cost of a short-distance telephone call using the network telephone system may be higher than the cost of making the same call using a normal telephone line. That is, the low-cost advantages of the network telephone system are generally limited to long-distance calls, and exclude short-distance calls. In addition, the service gateway may have to deal with a vast number of active subscribers during peak periods. At such times, the service gateway is liable to switch to a busy status, in which it is not able to cope with more call requirements. Newly active subscribers are made to  
           [0006]    Consequently, what is needed is an apparatus and method for network telephony that can convert the audio signals into the IP packets without the need for a service gateway.  
         SUMMARY OF THE INVENTION  
         [0007]    Accordingly, a primary object of the present invention is to provide a telephony apparatus for reliable and low-cost communication over a network.  
           [0008]    Another object of the present invention is to provide a telephony method for reliable and low-cost communication over a network.  
           [0009]    In order to fulfill the above-mentioned primary object, the present invention provides a telephony apparatus for communication over a network. The telephony apparatus comprises a user interface module for collecting audio input and broadcasting audio signals, a converter for converting digital signals into audio signals, an IP module for packing the digital signals into IP packets, a network interface module connected with the IP module for providing a communication interface between the telephony apparatus and the network, and a protocol/signaling controlling module connected with the converter and the IP module for exchanging communication protocols/signalings. The converter is connected with the user interface module, and also converts audio signals into digital signals. The IP module also unpacks IP packets into digital signals.  
           [0010]    In order to fulfill the other above-mentioned object, the present invention provides a method for telephonic communication over a network between a calling telephony apparatus and a called telephony apparatus. The method comprises the following steps: (a) transmitting a number of the called telephony apparatus to an IP module; (b) packing the number of the called telephony apparatus into an IP packet; (c) transmitting the IP packet to a call manager; (d) returning an IP address of the called telephony apparatus; and (e) communicating with the called telephony apparatus in a duplex manner.  
           [0011]    Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 is a schematic diagram of an application environment of a network telephone according to the present invention;  
         [0013]    [0013]FIG. 2 is a schematic diagram of hardware infrastructure of the network telephone according to the present invention;  
         [0014]    [0014]FIG. 3 is a schematic diagram of exemplary communication between two network telephones according to the present invention; and  
         [0015]    [0015]FIG. 4 is a flow chart of an exemplary method for communicating between two network telephones according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]    [0016]FIG. 1 is a schematic diagram of an application environment of a network telephone  10  according to the present invention. The network telephone  10  is coupled to a network  300 . The network  300  of the exemplary embodiment may be an asynchronous transfer mode (ATM) network, an Ethernet, or an IP network. The network  300  communicates with a call manager  400  and a public switched telephone network (PSTN) gateway  700  in a duplex manner. The call manager  400  is provided for dealing with call requirements from the network telephone  10 . A normal fixed-line type of telephone set  900  communicates with the PSTN gateway  700  by way of a PSTN  800 . The network telephone  10  and any other device such as a computer  500  communicate with the normal telephone  900  through the network  300 , the PSTN gateway  700  and the PSTN  800 .  
         [0017]    [0017]FIG. 2 is a schematic diagram of hardware infrastructure of the network telephone  10  according to the present invention. The network telephone  10  comprises a handset  101  for collecting audio input and broadcasting audio signals, a headset  102  for collecting audio input and broadcasting audio signals, a microphone  103  for collecting audio input, a speaker  104  for broadcasting audio signals, a converter  110 , an audio module  120 , an IP module  130 , a network interface module  140 , a protocol/signaling controlling module  150 , a liquid crystal display (LCD)  160 , a keypad  170 , and a ringer  180 .  
         [0018]    The ringer  180  is coupled to the handset  101 , the headset  102  and the speaker  104 , and is used for generating audio output such as a ringing tone, a dialing tone and a busy tone. The audio module  120  is connected with the converter  110 , and is for compressing/decompressing digital signals by using a digital signal processing (DSP) chip. The network interface module  140  is connected with the IP module  130 , and provides a communication interface between the network telephone  10  and the network  300  (see FIG. 1). The protocol/signaling controlling module  150  is connected with the converter  110 , the audio module  120 , the IP module  130  and the ringer  180 . The protocol/signaling controlling module  150  exchanges communication protocols/signalings with a called or calling party, such as the normal telephone  900  of FIG. 1 or another network telephone. The LCD  160  is connected with the protocol/signaling controlling module  150 , and displays a calling/called telephone number. The keypad  170  is connected with the protocol/signaling controlling module  150 , and is provided for dialing and encrypting.  
         [0019]    The converter  110  is connected with the handset  101 , the headset  102 , the microphone  103  and the speaker  104 . The converter  110  is for converting digital signals from the network  300  into audio signals, and transmitting the audio signals to the handset  101 , the headset  102 , or the speaker  104 . The converter  110  is also used for converting audio signals from the handset  101 , the headset  102  or the microphone  103  into digital signals, and transmitting the digital signals to the network  300 . The IP module  130  is connected with the audio module  120 . The IP module  130  is for packing digital signals compressed by the audio module  120  into IP packets, and transmitting the IP packets to the network interface module  140 . The IP module  130  is also used for unpacking IP packets transmitted by the network interface module  140  into digital signals, and transmitting the digital signals to the audio module  120 .  
         [0020]    [0020]FIG. 3 is a schematic diagram of exemplary communication between the network telephone  10  and a network telephone  20  according to the present invention. The network telephone  20  has a same configuration as the network telephone  10 . When a calling subscriber (not shown) calls the network telephone  20  by using the network telephone  10 , he/she picks up the handset  101  or the headset  102 , or uses the microphone  103 . The ringer  180  generates a dialing tone, and then transmits it to the handset  101 , the headset  102  or the speaker  104 . The calling subscriber dials a number of the network telephone  20  via the keypad  170 . Simultaneously, the LCD  160  displays the number of the network telephone  20 . The number of the network telephone  20  is transmitted from the keypad  170  to the IP module  130  by way of the protocol/signaling controlling module  150 . The IP module  130  packs the number of the network telephone  20  into an IP packet, and then transmits the IP packet to the call manager  400  by way of the network interface module  140  and the network  300 . The call manager  400  returns an IP address of the network telephone  20  to the network telephone  10 . According to the IP address, the network telephone  10  communicates with the network telephone  20  through the network interface module  140 , the network  300  and a network interface module  240 .  
         [0021]    At that time, the protocol/signaling controlling module  150  of the network telephone  10  exchanges communication protocols/signalings with a protocol/signaling controlling module  250  of the network telephone  20 . If the network telephone  20  is busy, it transmits a message to notify the network telephone  10  that it is busy. According to the message, the ringer  180  generates a busy tone, and then transmits it to the handset  101 , the headset  102  or the speaker  104 . If the network telephone  20  is free, the network telephone  10  determines a standard for compressing/decompressing digital signals with the network telephone  20 . The standard may be the international telecommunications union telecommunication standardization sector (ITU-T) G.711 standard, the ITU-T G.723 standard, or the ITU-T G.729 standard. Subsequently, a ringer  280  generates a ringing tone, and then transmits it to a speaker  204 . The speaker  204  broadcasts the ringing tone. Simultaneously, an LCD  260  displays a number of the network telephone  10 . Hearing the ringing tone, a called subscriber (not shown) can answer the call by using a handset  201 , a headset  202  or a microphone  203 . The audio signals of the called subscriber are transmitted to the network telephone  10  through a converter  210 , an audio module  220  and an IP module  230 . The communication between the network telephone  10  and the network telephone  20  is in a duplex manner. In addition, like the network telephone  10 , the network telephone  20  has a keypad  270  for dialing and encrypting.  
         [0022]    [0022]FIG. 4 is a flow chart of an exemplary method for communicating between the calling network telephone  10  and the called network telephone  20  according to the present invention. At step S 510 , after the calling subscriber dials a number of the called network telephone  20  via the keypad  170 , the number of the called network telephone  20  is transmitted from the keypad  170  to the IP module  130  by way of the protocol/signaling controlling module  150 . At step S 512 , the IP module  130  packs the number of the called network telephone  20  into an IP packet. At step S 514 , the IP module  130  transmits the IP packet to the call manager  400  by way of the network interface module  140  and the network  300 . At step S 516 , the call manager  400  returns an IP address of the called network telephone  20  to the calling network telephone  10 . At step S 518 , according to the IP address, the protocol/signaling controlling module  150  of the calling network telephone  10  exchanges communication protocols/signalings with the protocol/signaling controlling module  250  of the called network telephone  20 . If the called network telephone  20  is busy, the procedure goes to step S 520 . Otherwise, the procedure goes to step S 530 . At step S 520 , the called network telephone  20  transmits a message to notify the calling network telephone  10  that it is busy. At step S 522 , in response to the message, the ringer  180  generates a busy tone, and then transmits the busy tone to the handset  101 , the headset  102  or the speaker  104 . At step S 530 , the calling network telephone  10  determines a standard for compressing/decompressing digital signals with the called network telephone  20 . At step S 532 , the ringer  280  generates a ringing tone, and then transmits the ringing tone to the speaker  204 . The speaker  204  broadcasts the ringing tone to notify the called subscriber.  
         [0023]    While a preferred embodiment and preferred method of the present invention have been described above, it should be understood that they have been presented by way of example only and not by way of limitation. Thus the breadth and scope of the present invention should not be limited by the above-described exemplary embodiment and method, but should be defined only in accordance with the following claims and their equivalents.