Patent Abstract:
A mobile communication system in which a calling terminal transmits coding attribute identification information, and called terminal identification information to a central during call initiation. The coding attribute identifies the compression and coding process used by the calling terminal. A paging request generated by the central switching station is then addressed to the called terminal. The called terminal&#39;s response includes coding attribute information identifying its compression and coding process. If the coding and compression processes of the two terminals are the same, communication is conducted without conversion to PCM format. The audio signals transmitted by the calling and called terminals are continuously converted to PCM format at the associated base stations, but if the compression and coding processes of the participating terminals are the same, the unconverted audio signals (with coding attribute identification added) are transmitted. If the compression and coding processes do not match, the PCM signals are transmitted. At each base station, the incoming audio signals pass through PCM-to-native-format code converters. If the coding attribute identification is present in the incoming signal (indicating that the compression and coding processes of the two terminals match), the incoming unconverted audio signal is transmitted to the associated terminal. If the attribute identification is absent, the code converted signal is transmitted.

Full Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a mobile communication system, in particular, to a CODEC system for use with a base-station controlling unit. 
     2. Description of the Related Art 
     FIG. 5 shows a digital mobile communication system according to a first example of the prior art. Here, when a mobile terminal  1   a  calls a mobile terminal  1   b , a CODEC  41   a  of a base-station controlling unit  3   a  code-converts audio data of the mobile terminal  1   a  through a base station  2   a  into PCM audio data regardless of the attributes of, audio data of the mobile terminal  1   a  and the mobile terminal  1   b . The base-station controlling unit  3   a  transmits the PCM audio data to a mobile-terminal switching station  5 . The mobile-terminal switching station  5  transmits the PCM audio data received from the base-station controlling unit  3   a  to a base-station controlling unit  3   b  that accommodates the mobile terminal  1   b  on the called side. A CODEC  41   b  of the base-station controlling unit  3   b  code-converts the PCM audio data received from the mobile-terminal switching station  5  into the audio data with the attributes of the mobile terminal  1   b . The base-station controlling unit  3   b  transmits the resultant audio data to the mobile terminal  1   b  through a base station  2   b.    
     In this first related art reference, regardless of the attributes of audio data of the mobile terminal  1   a  on the calling side and the attributes of audio data of the mobile terminal  1 b on the called side, the base-station controlling unit  3   a  on the calling side and the base-station controlling unit  3   b  on the called side perform a code-converting process one time each (a total of two times). 
     Next, a second related art reference will be described. In the second related art reference, assuming that a mobile terminal transmits non-audio data such as FAX data to a terminal of the telephone network or another mobile terminal, a code-converting (CODEC) process is performed. When a mobile terminal transmits FAX data to a remote terminal, the mobile terminal on the calling side sets the communication mode to a FAX mode. However, at this point, the mobile terminal on the calling side determines whether the current mode thereof is an audio (telephone) mode or a non-audio (FAX) mode and notifies a relevant base station of the determined mode to the determined result. When the base station has received the notification that communication data is nonaudio data from the mobile terminal, the base station connects the communication data to a non-audio interface other than the audio CODEC interface so as to accomplish a non-audio communication with the terminal on the called side. 
     In other words, an object of the second related art reference is to simplify hardware of a base station in such a manner that a mobile terminal determines whether or not the current mode is audio data mode or non-audio data mode. 
     Next, the problems of the above-described related art references will be described. 
     In the first related art reference, when the attributes of audio data of the mobile terminal  1   a  on the calling side are the same as the attributes of audio data of the mobile terminal  1   b  on the called side, the base-station controlling unit  3   a  on the calling side code-converts audio data (with the attributes common in the mobile terminal  1   a  and the mobile terminal  1   b ) into PCM audio data. The base-station controlling unit  3   b  on the called side code-converts the PCM audio data code-converted by the base-station controlling unit  3   a  on the calling side into original audio data (with the attributes common in the mobile terminal la and the mobile terminal  1   b ). 
     Thus, although the attributes of audio data of the mobile terminal  1   a  on the calling side are the same as the attributes of audio data of the mobile terminal  1   b  on the called side, since the code-converting process is performed twice, the delay time of is audio data becomes large. In addition, the quality of audio data deteriorates. 
     The second related art reference is limited to non-audio (FAX) data communications. Further, 
     In the second related art reference, since a mobile terminal requires a data type determining circuit that determines whether data transmitted therefrom is audio data or non-audio data and a circuit that notifies a base station of the determined result, the additional circuitry increases the size of the mobile terminal. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to decrease the delay time of audio data being communicated between the mobile terminal  1   a  on the calling side and the mobile terminal  1   b  on the called side, to prevent the quality of audio data from deteriorating, and to accomplish such effects in a simpler call connecting sequence than before when the attributes of audio data of the mobile terminal  1   a  on the calling side are the same as the attributes of audio data of the mobile terminal  1   b  on the called side. 
     Another object of the present invention is to accomplish a simple method for monitoring audio data of two parties that are communicating with each other. 
     The present invention is a mobile communication system having a mobile-terminal switching station, a base-station controlling unit on the calling side, a base-station controlling unit on the called side, a base station, and mobile terminals, wherein the mobile-terminal switching station has a means for identifying attributes of audio data transmitted by the mobile terminal on the calling side and attributes of audio data of the mobile terminal on the called side, in the case and for prohibiting the base-station controlling unit on the calling side from transmitting a code-converting audio data when the attributes of the audio data of both mobile terminals are the same wherein the base-station controlling unit on the calling side has a means for selecting a first path of over which audio data received from the base station is output to the mobile-terminal switching station through a code-converting process or a second path of over which audio data received from the base station is output to the mobile-terminal switching station without a code-converting process, and a means for adding audio attribute information to audio data received from the base station, and wherein the base-station controlling unit on the called side has a means for identifying the audio attribute information added to the audio data received from the mobile-terminal switching station, and a means for selecting a first path over which audio data is output to the base station through a code-converting process or a second path over which audio data is output to the base station without code-converting process corresponding to the identified results. 
     The mobile terminal on called side has a means for identifying attributes of audio data of the mobile terminal on calling side and attributes of audio data of the mobile terminal on called side, and a means for prohibiting the base-station controlling unit on calling side from transmitting the code-converted audio data in the case that the attributes of the audio data of the mobile terminal on calling side match the attributes of the audio data of the mobile terminal on called side. 
     The base-station controlling unit on calling side has a means for prohibiting the base-station controlling unit on called side from transmitting the code-converted for audio data in the case that the attributes of the audio data of the mobile terminal on calling side match the attributes of the audio data of the mobile terminal on called side. 
     An audio monitor unit for monitoring audio data is connected to the mobile-terminal switching station, wherein the audio monitor unit has a means for identifying audio attribute information added by the base-station controlling unit to audio data being communicated between the mobile terminal on calling side and the mobile terminal on called side, and a means for determining whether or not the code-converting process for the audio data is required corresponding to the identified results, and wherein the audio monitor unit monitors audio data of the mobile terminal on calling side and audio data of the mobile terminal on called side, the mobile terminal on calling side and the mobile terminal on called side communicating in a CODEC-through manner. 
     These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of a best mode embodiment thereof, as illustrated in the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 is a block diagram showing the structure of a CODEC-through system according to an embodiment of the present invention; 
     FIG. 2 is a schematic diagram showing a first example of a call connecting sequence according to the present invention; 
     FIG. 3 is a schematic diagram showing a second example of the call connecting sequence according to the present invention; 
     FIG. 4 is a schematic diagram showing a third example of the call connecting sequence according to the present invention; and 
     FIG. 5 is a block diagram showing the structure of a related art reference. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Next, with reference to FIGS. 1 and 2, an embodiment of the present invention will be described. FIG. 1 is a block diagram showing the structure of an embodiment of the present invention. As shown in FIG. 1, a CODEC-through system according to the embodiment comprises mobile terminals  1   a  and  1   b , base stations  2   a  and  2   b , base-station controlling units  3   a  and  3   b , and a mobile-terminal switching station  5 . 
     The base-station controlling units  3   a  and  3   b  each comprise an upbound signal processing portion  31   a , a downbound signal processing portion  31   b , and call connection controlling portions  42   a  and  42   b . The upbound signal processing portion  31   a  comprises a CODEC  41   a , an audio type information adding portion  61   a , and an audio data selecting portion  62   a . The downbound signal processing portion  31   b  comprises a CODEC  41   b , an audio data type determining portion  61   b , and an audio data selecting portion  62   b . An audio data monitoring unit  8  comprises a CODEC  9   a , an audio data type determining portion  9   b , an audio data selecting portion  9   c , an adding portion  9   d , and an audio data outputting portion  9   e.    
     The CODECs  41   b  and  9   a  code-convert audio data into PCM audio data or vice versa corresponding to VSELP, QCELP, or PSI-CELP system. 
     Next, the operation of the CODEC-through system according to the embodiment will be described. When the mobile terminal  1   a  calls the mobile terminal  1   b , the mobile-terminal switching station  5  performs a call connection controlling process therebetween. In other words, the mobile-terminal switching station  5  determines the attributes of audio data of the mobile terminals  1   a  and  1   b . When the attributes of audio data of the mobile terminal  1   a  match the attributes of audio data of the mobile terminal  1   b , the mobile-terminal switching station  5  issues a command for prohibiting to transmission of code-converted the audio data to the base-station controlling unit  3   a  that accommodates the mobile terminal  1   a  on the calling side. 
     In the case of a TDMA communication system, audio data of a mobile terminal is transmitted corresponding to VSELP or PSI-CELP system. In the case of a CDMA communication system, audio data of a mobile terminal is transmitted corresponding to QCELP system. 
     Next, the operation of the base-station controlling unit  3   a  on the calling side will be described. The command issued by the mobile-terminal switching station  5  is transmitted to the call connection controlling portion  42   a  of the base-station controlling unit  3   a . When the call connection controlling portion  42   a  has received the command from the mobile-terminal switching station  5 , the call connection controlling portion  42   a  notifies the audio data type information adding portion (hereinafter referred to as adding portion)  61   a  of the fact that the attributes of audio data of the mobile terminal  1   a  on the calling side match the attributes of audio data of the mobile terminal  1   b  on the called side and of the attributes thereof. In addition, the call connection controlling portion  42   a  notifies the audio data selecting portion  62   a  of the fact that the attributes of audio data of the mobile terminal  1   a  on the calling side match the attributes of audio data of the mobile terminal  1   b  on the called side. When the adding portion  61   a  has received the notification from the call connection controlling portion  42   a , the adding portion  61   a  adds audio attribute information notified by the call connection controlling portion  42   a  to audio data received from the base stations  2   a  and outputs the resultant data to the audio data selecting portion  62   a.    
     Next, the operation of the upbound signal processing portion  31   a  of the base-station controlling unit  3   a  will be described. Audio data corresponding to VSELP or PSI-CELP system received from the base station  2   a  is sent to both the CODEC  4 ′ a  and the adding portion  61   a  of the upbound signal processing portion  31   a . The CODEC  41   a  code-converts audio data received from the base station  2  into PCM audio data regardless of the attributes of the audio data received therefrom and outputs the PCM audio data to the audio data selecting portion  62   a . When the adding portion  61   a  has received the notification that the attributes the audio data of the mobile termipal  1   a  on the calling side match the attributes of audio data the mobile terminal  1   b  on the called side, the adding portion  61   a  adds audio attribute information (of three bits) to the audio data received from the base station  2   a . However, the adding portion  61   a  does not code-convert the audio data. 
     When the adding portion  61   a  has not received the notification from the call connection controlling portion  42   a , the adding portion  61   a  directly outputs the audio data received from the base station  2   a  to the audio data selecting portion  62   a . When the audio data selecting portion  62  has received the notification that the attributes of audio data of the mobile terminal  1   a  on the calling side match the attributes of audio data of the audio terminal  1   b  on the called side from the call connection controlling portion  42   a , the audio data selecting portion  62  selects the audio data to which the audio attribute information has been added to the audio data received from the base station  2   a  (namely, the audio data that has not been code-converted by the CODEC  41   a ). Thereafter, the audio data selecting portion  62  outputs the selected audio data to the mobile-terminal switching station  5 . When the audio data selecting portion  62   a  has not received the notification from the call connection controlling portion  42   a , the audio data selecting portion  62   a  selects the audio data that has been code-converted into PCM audio data by the CODEC  41   a  and outputs the PCM audio data to the mobile-terminal switching station  5 . 
     Next, the operation of the base-station controlling unit  3   b  on the called side will be described. Audio data received from the mobile-terminal switching station  5  is sent to both the CODEC  41   b  and the audio data type determining portion  61   b  of the downbound signal processing portion  31   b . The CODEC  41   b  code-converts audio data received from the mobile-terminal switching station  5  into audio data with the attributes common to all mobile terminals  1   b  on the called side. 
     The audio data type determining portion  61   b  determines whether or not audio attribute information has been added to audio data received from the base-station controlling unit  3   a  through the mobile-terminal switching station  5 . When audio attribute information has been added to audio data, the audio data type determining portion  61   b  causes the audio data selecting portion  62   b  to select audio data that has not been code-converted by the CODEC  41   b  and to output the selected audio data to the base station  2   b . When audio attribute information has not been added to audio data, the audio data type determining portion  61   b  causes the audio data selecting portion  62   b  to select audio data that has been code-converted by the CODEC  41   b  and to output the selected audio data to the base station  2   b.    
     Next, with reference to FIG. 2, a first example of the call connecting sequence of the CODEC-through system according to the embodiment of the present invention will be described. When the mobile terminal  1   a  calls the mobile terminal  1   b , the mobile terminal  1   a  transmits a call connection request (SET UP) to the mobile-terminal switching station  5  through the base station  2   a  and the base-station controlling unit  3   a . When the mobile-terminal switching station  5  has received the call connection request (SET UP), the mobile-terminal switching station  5  transmits a call (PAG REQUEST) to a plurality of base-station controlling units. Thus, the mobile-terminal switching station  5  also transmits the call (PAG REQUEST) to the base-station controlling unit  3   b . The mobile terminal  1   b  that has received a call (PAG MESSAGE) from the mobile-terminal switching station  5  sends back a response (AUTH RES) to the mobile-terminal switching station  5 . 
     In the process, the mobile-terminal switching station  5  identifies the attributes of audio data of the mobile terminal  1   a  corresponding to CODEC INF included in the call connection request (SET UP). In addition, the mobile-terminal switching station  5  identifies the attributes of audio data of the mobile terminal  1   b  corresponding to CODEC INF included in the response (AUTH RES) received from the mobile terminal  1   b  through the base-station controlling unit  3   b . When the attributes of audio data of the mobile terminal  1   a  match the attributes of audio data of the mobile terminal  1   b , after the mobile-terminal switching station  5  performs a certificating process and a channel-allocating process, the mobile-terminal switching station  5  transmits a response (ALERT) to the base-station controlling.unit  3   a  and thqn a command (CODEC REQ) for prohibiting transmission code-converted audio to the base-station controlling unit  3   a.    
     When the base-station controlling unit  3   a  has received the command (CODEC REQ), the base-station controlling unit  3   a  sends back a response (CODEC RES) that represents an acknowledgment of the command (CODEC REQ) to the mobile-terminal switching station  5 . After the mobile-terminal switching station  5  has received the response command (CODEC RES), the mobile-terminal switching station  5  performs the conventional call connecting process so that the mobile terminals  1   a  and  1   b  communicate with each other. After both the mobile terminals  1   a  and  1   b  have communicated with each other, the base-station controlling unit  3   a  on the calling side adds audio attribute information to audio data that has not been code-converted in the process shown in FIG.  1  and outputs the resultant audio data to the mobile-terminal switching station  5 . 
     The base-station controlling unit  3   b  on the called side identifies audio attribute information (that has been added to audio data being communicated) by the base-station controlling unit  3   a  on the calling side. Thereafter, in the process shown in FIG. 1, the base-station controlling unit  3   b  on the called side autonomously selects audio data that has not been code-converted and outputs the selected audio data to the base station  2   b . After the call connecting process is completed and a communication is started, the base-station controlling unit  3   a  adds audio attribute information to the audio data that is being communicated. In addition, the base-station controlling unit  3   b  always identifies the audio attribute information. Thus, a communication can be made without the code-converting process. 
     Next, with reference to FIGS. 1 and 3, a second example of the call connecting sequence of the CODEC-through system according to the embodiment of the present invention will be described. In the first example, which the mobile-terminal switching station  5  prohibits the base-station controlling unit  3   a  on the calling side from transmitting the code-. 
     In the second example, with reference to FIG. 3, the base-station controlling unit  3   b  on the called side prohibits the base-station controlling unit  3   a  on the calling side When the mobile terminal  1   a  calls the mobile terminal  1   b , the mobile-terminal switching station  5  adds CODEC INF included in the call connection request (SET UP) to the command (PAG REQUEST) that is transmitted to each base-station controlling unit. 
     The call connection controlling portion  42   b  of the base-station controlling unit  3   b  of a plurality of base-station controlling units identifies the attributes of audio data of the mobile terminal  1   a  corresponding to the CODEC INF included in the command (PAG REQUEST). In addition, the call connection controlling portion  42   b  identifies the attributes of audio data of the mobile terminal  1   b  corresponding to CODEC INF included in the response (AUTH RES) received from the mobile terminal  1   b  through the base-station controlling unit  3   b.    
     When the attributes of audio data of the mobile terminal  1   a  match the attributes of audio data of the mobile terminal  1   b , after the call connection controlling portion  42   b  performs a certificating process and a channel-allocating process, the call connection controlling portion  42   b  issues a command (CODEC REQ) for prohibiting transmission of code-converted voice signal to the base-station controlling unit  3   a  on the calling side through the mobile-terminal switching station  5 . The connection controlling portion  42   a  of the base-station controlling unit  3   a  receives the command (CODEC REQ). 
     When the call connection controlling portion  42   a  has received the command (CODEC,REQ), the call connection controlling portion  42   a  transmits a response (CODEC RES) to the command (CODEC REQ) to the base-station controlling unit  3   b  on the called side through the mobile-terminal switching station  5 . Thereafter, the call connection controlling portion  42   a  causes the adding portion  62   a  to add audio attribute information to the audio data. In addition, the call connection controlling portion  42   a  causes the audio data selecting portion  62   a  to select audio data that has not been code-converted by the CODEC  41   a  and to output the selected audio data. 
     When the call connection controlling portion  42   b  has received the response (CODEC RES), the call connection controlling portion  42   b  causes the audio data selecting portion  62   b  to select audio data that has not been code-converted by the CODEC  41   b  and to output the selected audio data. After the call connecting process is completed and a communication is started, the base-station controlling unit  3   a  adds audio attribute information to audio data being communicated. In addition, the base-station controlling unit  3   b  always identifies the audio attribute information. Thus, a communication can be made without the code-converting process. 
     Next, with reference to FIGS. 1 and 4, a third example of the call connecting sequence of the CODEC-through system according to the embodiment will be described. In the second example, the base-station controlling unit  3   b  on the called side identifies audio attribute information added to audio data being communicated and thereby autonomously determines whether or not the code-converting process is required without need for intervention by the mobile-terminal switching station  5  and the base-station controlling unit  3   a.    
     In the third example, the base-station controlling unit  3   b  on the called side determines whether or not the code-converting process is required corresponding to a command received from the base-station controlling unit  3   a  in the call connection process. The mobile-terminal switching station  5  identifies the attributes of audio data of the mobile terminal  1   a  corresponding to CODEC INF included in the call connection request (SET UP). In addition, the mobile-terminal switching station  5  identifies the attributes of audio data of the mobile terminal  1   b  corresponding to CODEC INF included in the response (AUTH RES) received from the mobile terminal  1   b  through the base-station controlling unit  3   b.    
     When the attributes of audio data of the mobile terminal  1   a  match the attributes of audio data of the mobile terminal  1   b , after the mobile-terminal switching station  5  performs a certificating process and a channel-allocating process, the mobile-terminal switching station  5  transmits the response (ALERT) to the base-station controlling unit  3   a . Thereafter, the mobile-terminal switching station  5  issues the command (CODEC REQ) for prohibiting transmission of code-converted audio to the base-station controlling unit  3   a.    
     When the base-station controlling unit  3   a  has received the command (CODEC REQ), the base-station controlling unit  3   a  sends back the response (CODEC RES) that represents an acknowledgment of the command (CODEC REQ) to the mobile-terminal switching station  5 . Thereafter, the base-station controlling unit  3   a  transmits the command (CODEC REQ) for prohibiting transmission of code-converted audio to the base-sation controlling unit  3   b  through the mobile-terminal switching station  5 . The call connection controlling portion  42   b  of the base-station controlling unit  3   b  receives the command (CODEC REQ). 
     When the call connection controlling portion  42   b  has received the command (CODEC REQ), the call connection controlling portion  42   b  causes the selecting portion  62   b  to select audio data that has not been code-converted by CODEC  41   b  and to output the selected audio data to the base station  2   b . After the call connecting process is completed and a communication is started, the base-station controlling unit  3   a  adds audio attribute information to audio data that is being communicated. The base-station controlling unit  3   b  always identifies the audio attribute information. Thus, a communication can be made without the code-converting process. 
     Next, with reference to FIG. 1, the structure and operation of an audio monitor unit according to an embodiment of the present invention will be described. The audio monitor unit  8  comprised of a first signal patch  9  including an audio data type determining portion  9   b , an audio data selecting portion  9   c , and the CODEC  9   a . Audio monitor unit  8  is also comprised of a second signal path  10  including a CODEC  10   a , an audio data type determining portion  10   b  and an audio data selecting portion  10   c . Signal paths  9  and  10  each to monitor audio data received from one of the mobile terminals  1   a  and  1   b  that are in communication regardless of the attributes of the audio data. For example signal path  9  monitors audio data from calling-side terminal  1   a , and signal path  10  monitors audio data from called-side mobile terminal  1   b . As previously explained, if the attributes of the calling terminal  1   a  match the attributes of terminal  1   b , the mobile-terminal switching station  5  receives audio data that has not been code-converted into PCM audio data. To monitor such audio data, it is necessary to determine the attributes of audio data that is being communicated and code-convert the audio data in accordance with its attributes into PCM audio data. 
     As shown in FIG. 1, the audio data type determining portions  9   b  and  10   d  respectively determine the attributes of audio data of the mobile terminals  1   a  and  1   b . When audio attribute information has teen added to audio data, the determining portions  9   b  and  10   b  cause the attribute audio data selecting portions  9   c  and  10   c  to select audio data that has been code-converted to PCM audio CODEC  9   a  and CODEC  10   a , and to output the selected audio data on adder  11 . When audio attribute information has not been added to audio data, the audio data will be in PCM form, and further code conversion is not needed. Thus, the determining portions  9   b  and  10   b  causes the audio data selecting portions  9   c  and  10   c  to select audio data that has not been code-converted by the CODECS  9   a  and  10   a  and to output the selected audio data to adder  11 . Thus, audio data that is output from the audio data selecting portions  9   c  and  10   c  are always PCM audio data. 
     The adding portion  11  digitally adds both the audio data and sends the resultant audio data to the audio data outputting portion  12 . The audio data outputting portion  12  decodes the PCM audio data, amplifies the resultant audio data, and outputs the resultant audio data as a sound. Thus, the audio monitoring unit  8  can monitor audio data of two communicating parties regardless of the attributes of the audio data without need to receive a command from the mobile-terminal switching station  5 . 
     According to the present invention, when mobile terminals having the same attributes of audio data communicate with each other, since it is not necessary to perform the code-converting process (unlike with the conventional system that requires the code-converting process two times), the delay time of audio data can be decreased. In addition, the quality of audio data can be prevented from deteriorating. 
     In addition, according to the present invention, since a base-station controlling unit on the calling side has a means for prohibiting transmission of code-converted audio to a base-station controlling unit on the called side and a means for identifying audio attribute information added to audio data, the base-station controlling unit on the calling side can autonomously determine whether or not the code-converting process is required without interventions of a mobile-terminal switching station and the base-station controlling unit on the called side. Thus, the above-described effects can be accomplished in a simpler call connecting sequence than before. 
     Moreover, according to the present invention, an audio monitor unit has a means for identifying audio attribute information added to audio data and a means for determining whether or not the code-converting process is required corresponding to the identified results, the audio monitor unit can monitor audio data of two parties that are communicating with each other regardless of the attributes of the audio data thereof. 
     Although the present invention has been shown and described with respect to a best mode embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions, and additions in the form and detail thereof may be made therein without departing from the spirit and scope of the present invention.

Technology Classification (CPC): 7