Abstract:
A hybrid interface apparatus for a key telephone system is disclosed, which apparatus is capable of interfacing a data and voice communication between a terminal such as a key telephone, a mobile telephone, a computer, etc. and a key telephone system. The hybrid interface apparatus according to the present invention includes more than at least one key telephone unit, a main apparatus for connecting the key telephones, a personal computer, and a multi-module connected between the main apparatus and a key telephone unit, a mobile telephone and a personal computer for interfacing a wire-based communication, a wireless communication and a data communication.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an interface apparatus for a key telephone system, and in particular to a composite interface apparatus for a key telephone system which is capable of interfacing a data and voice communication between a terminal such as a key telephone, a mobile telephone, a computer, etc. and a key telephone system. 
     2. Description of the Background Art 
     Generally, a keyphone system represents a key telephone system. The key telephone system includes a plurality of keyphones, and an apparatus for connecting the keyphones. Each keyphone includes a line selection button for commonly using a telephone line. 
     As shown in FIG. 1, a conventional key telephone system includes a main apparatus  100  and a key telephone unit (KTU)  102 . The KTU  102  includes a digital adapter subscriber loop IC hereinafter called DASL) and is connected with a DASL  10  of the main apparatus. Therefore, a voice communication is performed between the main apparatus  100  and the KTU  102  through a DASL. 
     Recently, as a wireless communication and a computer communication are rapidly advanced, the needs for a voice communication as well as a wireless communication and a data communication are increased. However, in the conventional keyphone system, since only a voice communication is available, it is impossible to satisfy user&#39;s various demands. 
     In addition, in the conventional keyphone system, in order to implement a wireless communication and a data communication, an apparatus is additionally needed, so that it is inconvenient to use the system, and the fabrication cost of the system is increased. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a hybrid interface apparatus for a keyphone system which is capable of interfacing a data and voice communication between a terminal such as a key telephone, a mobile telephone, a computer, etc. and a key telephone system. 
     It is another object of the present invention to provide a hybrid interface apparatus for a keyphone system in which a mobile telephone and a computer are available, and a voice and data transmission is available. 
     It is still another object of the present invention to provide a multi-module of a hybrid interface function for easily connecting a keyphone, a mobile telephone and a computer to a conventional keyphone system. 
     To achieve the above object, there is provided a hybrid interface apparatus which includes more than at least one key telephone unit, a main apparatus for connecting the key telephones, a personal computer, and a multi-module connected between the main apparatus and a key telephone unit, a mobile telephone and a personal computer for interfacing a wire-based communication, a wireless communication and a data communication. 
     To achieve the above objects, there is provided a multi function module which includes first and second digital adapter subscriber loop(DASL) ICs for transmitting and receiving a voice signal and a data signal with the main apparatus and the KTU in an AMI signal format, a RF module for transmitting and receiving a high frequency signal with a mobile telephone, a series interface for transmitting and receiving a data with a PC(Personal Computer), first and second CODECs connected with the first and second DASL ICs, an analog switch connected between the first and second CODECs and the RF module for switching a voice signal of the first CODEC to the second CODEC and the RF module and switching the voice signals of the second CODEC and the RF module to the first CODEC, and a CPU(Central Processing Unit) for searching a header information of the data signal outputted from the first DASL, controlling the analog switch, carrying a header information on the data signals which are outputted from the second DASL, the RF module, and the series interface to the first DASL. 
     Additional advantages, objects and features of the invention will become more apparent from the description which follows. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
     FIG. 1 is a block diagram illustrating a conventional keyphone system; 
     FIG. 2 is a block diagram illustrating a composite interface apparatus for a keyphone system according to the present invention; 
     FIG. 3A is a view illustrating the formats of a data signal transmitted from a main apparatus to a multi-module and a data signal transmitted from a multi-module to a KTU, a PC and a mobile telephone; and 
     FIG. 3B is a view illustrating the formats of a data -signal transmitted from a multi-module to a main apparatus and a data signal transmitted from a KTU, a PC and a mobile telephone to a multi-module. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The embodiments of the present invention will be explained with reference to the accompanying drawings. 
     As shown in FIG. 2, a composite interface apparatus for a keyphone system according to the present invention includes a main apparatus  100 , a multi-module  101 , a mobile telephone  103 , and a personal computer (PC)  104 . 
     The multi-module  101  interfaces a voice communication and a data communication between the KTU  102 , the mobile telephone  103 , the PC  104 , and the main apparatus  100 . 
     The multi-module  101  includes a DASLs  11  and  15  for transmitting and receiving an alternate mark inversion(AMI) signal to/from a DASL  10  of the main apparatus  100  or a DASL(not shown) of the KTU  102  using a 2B+D channel structure, respectively. Each of the DASLs  11  and  15  codes a data signal and a voice signal into an AMI signal or decodes the AMI signal into a data signal and a voice signal. In addition, the multi-module  101  includes a CPU(Central Processing Unit)  14 , a series interface  13 , CODECs  12  and  16 , an analog switch  17 , and a RF module  18 . 
     The CODECs(Coder and Decoder)  12  and  16  performs a conversion operation between a digital voice signal and an analog voice signal, and the CPU  14  judges whether a corresponding data is transmitted to the KTU  102  based on a header information of the data decoded by the DASL  11  or is transmitted to the PC  104  or is transmitted to the mobile telephone  103 . In addition, the CPU  14  receives a data from the DASL  15  or the RF module  18 , and carries a header information which represents whether a corresponding data is the data of the KTU  102  or the mobile telephone  103  or the PC  104 . 
     The analog switch  17  switches an analog voice signal outputted from the CODEC  12  to the RF module  18  or the CODEC  16  in accordance with a control of the CPU  14  or switches an analog voice signal, which is outputted from the RF module  18 , to the CODEC  12 . 
     The series interface  13  transmits and receives in series a data with the PC  104  using a communication method of a RS-232 standard. The RF module  18  performs a multi-channel access(MCA) communication of 40 channels with the mobile telephone  103  by an analog method of 900 MHz. 
     The operation of the composite interface apparatus for a keyphone system according to the present invention will be explained with reference to the accompanying drawings. 
     The DASL  10  of the main apparatus  100  transmits a voice signal through a B-channel of the 2B+D channel using an AMI signal and outputs a data signal through a D-channel of the 2B+D channel in a format shown in FIG.  3 A. At this time, the data signal is formed of a start bit of 4-bit, a DATA  1  of 8-bit, a DATA  2  and DATA  3  of 8-bit which is an actual data, and a parity bit of 4-bit for checking errors. In addition, the DATA  1  of 8-bit is formed of a header information of 3-bit and a data type(LCD, LED, voice control) information of 5-bit. 
     The DASL  11  of the multi-module  101  decodes an AMI signal transmitted from the main apparatus  100  through the B-channel and the D-channel, and the data signal of the D-channel is outputted to the CPU  14 , and the voice signal of the B-channel is outputted to the CODEC  12  and is converted into an analog voice signal. 
     Therefore, the CPU  14  checks an availability of a data signal, a destination(KTU or mobile telephone), an error, etc. and determines an output path of a data signal and a voice signal. Namely, the CPU  14  checks a start bit of 4-bit of the data signal and judges an availability of an input data. At this time, if the start bit is set to “0101”, it is judged that the data is valid. 
     The CPU  14  checks a header information of 3-bit included in DATA  1  and determines whether a data signal is transmitted to the KTU  102  or the mobile telephone  103  or the PC  104 . Thereafter, the error check is performed using a parity bit of 4-bit. 
     
       
         
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Header information 
                 Destination 
               
               
                   
               
             
             
               
                 000 
                 PC 
               
               
                 010 
                 KTU 
               
               
                 001 
                 Mobile telephone 
               
               
                   
               
             
          
         
       
     
     Namely, the CPU  14  judges the destination of the data signal from the DASL  11  in accordance with a header information of three types shown in Table 1. 
     If the header information is “000”, the CPU  14  outputs a data signal to the series interface  13  for thereby implementing a data communication between the series interface  13  and the PC  104  by a tone method based on the RS- 232  standard. In addition, if the header information “010”, the CPU  14  transmits the data signal to the DASL  15  and controls the analog switch  17  so that an analog voice signal of the CODEC  12  is inputted into the DASL  15  through the CODEC  16 . 
     Therefore, the DASL  15  codes a data signal and a voice signal into an AMI signal and transmits to the KTU  102  for thereby implementing a wire-based voice communication. Namely, the DASL  15  transmits a voice signal through the B-channel of the 2B+D channel identically to the DASL  10 , and the data signal is outputted through the D-channel of the 2B+D channel in a format shown in FIG.  3 A. 
     In addition, if the header information is “001”, the CPU  14  transmits a data signal to the RF module  18  and controls the analog switch  17  so that an analog voice signal from the CODEC  12  is inputted into the RF module  18 . Therefore, the RF module  18  performs a wireless voice communication with the mobile telephone  103  by the MCA method. 
     When a user of the KTU  102  performs a voice communication to the main apparatus  100 , the DASL  15  of the multi-module  101  decodes an AMI signal outputted from the DASL(not shown) of the KTU  102  and outputs a data signal to the CPU  14  and outputs a voice signal to the CODEC  16 . 
     At this time, as shown in FIG. 3B, the format of the data transmitted from the KTU  102  to the main apparatus  100  is formed of a start bit of 4-bit, a DATA  1  of 8-bit, a DATA  2  of 8-bit which is an actual data, and a parity bit of 4-bit for checking errors. In addition, the DATA  1  of 8-bit is formed of a header of 3-bit which represents the type(KTU, mobile telephone and PC) of the terminal and a data of 5-bit which represents an ID of the terminal and multi-module  101 . Therefore, in the case of the KTU  102 , the data of 5-bit represents a KTU ID, for example, a LCD phone:  01 , non-LCD phone: 02 , multi-module: 03 , and the DATA  2  represents a number of the KTU. 
     Therefore, the CPU  14  carries a header information “010” of the KTU  102  on a data outputted from the DASL  15  and outputs to the DASL  11  and controls the analog switch  107  so that an analog voice signal of the CODEC  16  is inputted into the DASL  11  through the CODEC  12 . As a result, the DASL  15  codes the data signal and voice signal into an AMI signal and outputs to the main apparatus  100 . At this time, the data signal is transmitted through one B-channel of the 2B channels in a format shown in FIG. 3B, and the voice signal is transmitted through the D-channel. 
     In addition, a user of the mobile telephone  103  performs a wireless voice communication to the main apparatus  100 , the RF module  18  of the multi-module  101  is outputted to the CPU  14 , and a voice signal is outputted to the analog switch  17 . At this time, the 5-bit data except for the header in the DATA  1  represents an ID of the mobile telephone  103 , and the DATA  2  represents an actual data such as a number of the mobile telephone  103  which will be called. 
     The CPU  14  carries a header information “001” of the mobile telephone  103  on a data signal outputted from the RF module  18  and controls the analog switch  17  so that an analog voice signal from the RF module  18  is inputted into the DASL  11 . 
     Therefore, the DASL  15  codes an inputted data signal and a voice signal into an AMI signal, and the voice signal is outputted to the main apparatus  100  through the remaining B-channel of the 2B channel in the format of FIG. 3B, and the data signal is outputted to the main apparatus  100  through the D channel. Therefore, a user uses the KTU  102  and the mobile terminal  103  based on the multi-module  101 . 
     In addition, in the case that a data is outputted from the PC  104  to the main apparatus  100 , the data signal transmitted from the PC  104  is inputted into the CPU  14  through the series interface  13 . The CPU  14  carries a header information “000” on a corresponding signal and outputs to the DASL  11 . The DASL  11  outputs a data signal to the main apparatus  100  through the D channel. At this time, the 5-bit data except for the header in the DATA  1  represents a destination, a nd the DATA  2  represents an actual data. Therefore, a data communication is implemented between the PC  104  and the main apparatus  100 . 
     The present invention is not limited to the above-disclosed embodiments. Under an environment that the ISDN(Integrated Service Digital Network) is widely used, and the communication ratio of the PC  104  is increased, a high speed data communication may be implemented by simply modifying a related software and hardware, so that the PC data is transmitted through the B channel. 
     As described above, in the present invention, a keyphone as well as a mobile telephone and a computer may be easily connected with the keyphone system through the multi-module, so that it is possible to implement a total solution for a voice communication, mobile communication and data communication. 
     In the present invention, since it is possible to easily perform a wireless communication and data communication by connecting a multi-module to the known keyphone system, it is easy to use the system, and the fabrication cost increase due to an additional apparatus is prevented. 
     In addition, since it is possible to perform a wire-based communication, wireless communication and data communication using one line, a reliability of a communication line is enhanced. 
     Although the preferred embodiment of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as recited in the accompanying claims.