System and method for supporting voip and cs telephone

A system for supporting Voice over Internet Protocol (VOIP) and Circuit Switch (CS) telephone, comprising a terminal gateway device, a wireless broadband module, a Subscriber Line Interface Circuit (SLIC) and a SWITCH, wherein

• the wireless broadband module is used for realizing network registration of a VOIP call, connection to a WAN and establishment of a CS call, and completing transmission of a voice code stream between the terminal gateway device and a wireless broadband network;
• further for establishing a CS connection if a CS voice code stream is transmitted through a Pulse Code Modulation (PCM) line from the SLIC to the wireless broadband module, converting a PCM line signal into a CS voice code stream and sending the converted CS voice code stream to the wireless broadband network, and converting a CS voice code stream from the wireless broadband network into a PCM line signal;
• the terminal gateway device is used for determining whether a currently initiated call is a VOIP call or a CS call according to a received signal;
• if the currently initiated call is a VOIP call, establishing a Session Initiation Protocol (SIP) connection via the wireless broadband module, converting a PCM line signal into a VOIP voice code stream, and sending the converted VOIP voice code stream to the wireless broadband network via the wireless broadband module or converting a VOIP voice code stream from the wireless broadband module into a PCM line signal;
• if the currently initiated call is a CS call, establishing a CS connection via the wireless broadband module, converting a PCM line signal into a CS voice code stream, and sending the converted CS voice code stream to the wireless broadband network via the wireless broadband module or converting a CS voice code stream from the wireless broadband module into a PCM line signal;
• the terminal gateway device is further used for determining whether a PCM line for transmitting a CS voice code stream is from the SLIC to the terminal gateway device or from the SLIC to the wireless broadband module, and controlling the SWITCH to establish a corresponding PCM line for transmitting the CS voice code stream;
• the SLIC is used for bidirectional transmission of a Serial Peripheral Interface (SPI) signal between a telephone and the terminal gateway device as well as bidirectional transmission of a PCM line signal between a telephone and the SWITCH;
• and
• the SWITCH is used for transmission of a VOIP voice code stream between the terminal gateway device and the SLIC, and establishment of a PCM line from the SLIC to the terminal gateway device or to the wireless broadband module for transmitting a CS voice code stream.

A method for supporting Voice over Internet Protocol (VOIP) and Circuit Switch (CS) telephone, comprising a calling process and a called process, wherein

• the calling process mainly comprises:
• a user picks up a telephone, an off-hook signal is sent to a terminal gateway device via a Serial Peripheral Interface (SPI), the terminal gateway device plays an off-hook tone and sends the off-hook tone to the telephone via a Subscriber Line Interface Circuit (SLIC), and the off-hook tone is played to the user via the telephone;
• the user dials a VOIP or CS number in different ways, and the terminal gateway device identifies a dialing signaling;
• the user establishes a VOIP or CS communication connection with a called party, a Pulse Code Modulation (PCM) line signal of each of the communications is converted into a corresponding voice code stream and then the corresponding voice code stream is transmitted to the called party, and a voice code stream of the called party is converted into a PCM line signal and then the PCM line signal is transmitted to the caller;
• and
• the user hangs up, the terminal gateway device detects a hand-up button and releases the communication connection;
• and the called process comprises:
• the terminal gateway device receives a call request from the caller and determines whether the received call request is a VOIP request or a CS request;
• the called party establishes a VOIP or CS session connection with the caller, and the SLIC transmits ring information and a telephone number to the telephone;
• the called party picks up a telephone, a VOIP or CS voice code stream is converted into a PCM line signal and then the PCM line signal is transmitted to the SLIC via a PCM line and finally to the user via the telephone, and a PCM line signal of the called party is converted into a VOIP or CS voice code stream and then the VOIP or CS voice code stream is transmitted to the caller;
• and
• the called party hangs up, and a wireless broadband module sends a received link removal request to the terminal gateway device, the terminal gateway device releases the session, and the whole call process is ended.