Abstract:
A system with a mobile phone capable of receiving a paging message. A method and apparatus automatically transmits a callback message to a callback number associated with the caller in response to a page message. The user of the system prepares a data structure in which a caller ID of each of the prospective callers in associated with information on the caller as well as the caller&#39;s communication device. In response to the reception of a page message, the user can display a response message used for calling back the caller when the user is busy. When the user selects the response message, the call back message is compiled using a call back number associated with a caller ID contained in the page message. The callback message can then be sent to the caller.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a mobile paging telephone with a text (or character) message receiving capability and, particularly to, a system and a method applicable to such a telephone for automatically calling back a call back number associated with a caller transmitting one of predetermined text massages to the number in situations where a called party or a carrier of the telephone device can not call back immediately. 
     2. Description of the Prior Art 
     Various mobile paging telephones or mobile phones with a paging receiver have been proposed for far. One of such mobile paging telephones are disclosed in U.S. Pat. No. 5,559,862 (1996). With such a mobile paging telephone, a subscriber or a carrier of the telephone can receive a page message containing a call back number via a paging station from a caller. A predetermined operation by the subscriber will cause the call back number to be automatically dialed permitting him or her to communicate with the caller over the telephone. This enables the caller, who usually does not know the location of the subscriber or called party, to get in touch with him or her at any time the caller wants if he/she is in a situation where he/she can be on the phone in person at that time. 
     However, there may be cases where the called party can not call the caller back immediately. For example, the called party may be attending a conference, or talking on the phone over a matter which needs to be settled but which it takes some time to settle when he/she is paged. In these situations, the caller can not get any response, nor can he/she know whether the party to be called has been actually paged and got the page message. 
     Thus, a need exists in the art for a mobile paging telephone capable of automatically calling back a call back number associated with a caller transmitting one of predetermined text massages to the call back number. This enable the called party to inform the caller of the reception of the page message and rough information a situation of the called party. However, the call back operation may not be achieved successfully, which is the case for example when the called party is outside of the cellular telephone service area and/or when the paging station serving the mobile paging telephone is busy (these situations are hereinafter referred to as “routing failure situations”). 
     A further need exists in the art for a mobile paging telephone which repeats call back operations till both of the routing failure situations is settled. 
     SUMMARY OF THE INVENTION 
     These and other needs are met by a system and a method used in a mobile paging telephone for automatically transmitting one of prepared response messages which is specified by the user to a call back number associated with the caller in accordance with the present invention. The present invention is applicable to any device provided with a text (or character) message receiving function and a mobile or cellular telephone. A user of the system can prepare a data structure in which a caller ID of each prospective caller is associated with information on the caller and caller&#39;s communication device in which he receives a call. It is assumed that the call back number includes a telephone number, a mobile phone number, a pager number, etc. If the system receives a page message from a caller, the system displays the prepared response messages when the user is too busy to call back, in response to the user or subscriber operating a predetermined control switch and prompts the user to select one of the displayed response messages. Selecting a response message causes a call back message to be compiled from a call back number associated with a caller ID contained in the page message and the selected response message. For this purpose, the system has a table which, for each of prospective callers, contains a record comprising a caller ID and a name of the prospective caller, and a call number and a type of his or her information device which the caller wants a call to be directed. The call back message is transmitted to the call back number. The compilation of call back message is performed such that the format of call back message is adapted to the type of the caller&#39;s device associated with the caller ID in the table. A paged time (i.e., a time when the paging call has been received from the caller) and/or the called party&#39;s name may be included in the call back message. This ensures the caller to receive a call back message including such information. 
     If the transmission of call back message is to be done in a situation where the mobile phone is busy, a situation where a paging station serving the mobile phone is busy and/or a situation where the mobile phone is located out of a service area, then the transmission operation is repeatedly attempted at a preset time interval till all of the situations are resolved. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawing, in which: 
     FIG. 1 is a block diagram showing an arrangement of a mobile paging telephone in accordance with an illustrative embodiment of the invention; 
     FIG. 2 is a diagram showing how page and call back messages are routed; 
     FIG. 3 is a diagram showing exemplary structures of the page message and the call back message used in the illustrative embodiment of the invention; 
     FIG. 4 is a flow chart of a program module stored in ROM  102  and executed by CPU  101  when CPU  101  or the controller  100  receives the communication text  302  and the caller ID  303  from the paging receiver portion  110 ; 
     FIG. 5 is a call number table which is stored in the nonvolatile memory  104  and which contains information on a call back destination associated with each of prospective callers; 
     FIG. 6 is a diagram showing examples of the return communication texts  350  in detail; 
     FIG. 7 is a diagram showing an exemplary screen displayed on the display device  140  in step  406 ; 
     FIG. 8 is a flow chart of a program module  412   a  stored in ROM  102  and executed in place of step  412  of FIG. 4; 
     FIG. 9 is a flow chart of a program module  412   b  stored in ROM  102  and executed in place of step  412  of FIG. 4; and 
     FIG. 10 is a diagram showing an electric field level check step which can be replaced with a routine  900  of FIG. 9 to ensure a predetermined level of electric field. 
    
    
     Throughout the drawing, the same elements when shown in more than one figure are designated by the same reference numerals. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 is a block diagram showing an arrangement of a mobile paging telephone (or a mobile phones with a paging receiver) in accordance with an illustrative embodiment of the invention. In FIG. 1, the mobile paging telephone  1  comprises a paging receiver portion  110  responsive to a call addressed thereto for providing a page message carried by the call, a mobile phone portion  120 , a controller  100  for controlling the portions  110  and  120 , a control switch  130  through which the user controls the telephone  1 , a display  140  on which the controller  100  displays various information, and a sounder/vibrator  150  for providing a sound or vibration output for alerting the user. 
     The paging receiver portion  110  comprises a paging receiver antenna  111  for receiving radio waves, an FM (frequency modulation) tuner  112  for extracting an FM page signal from the received radio waves, a demodulator  113  for demodulating the FM page signal, a pager number memory  114  for storing a pager number having been assigned to the mobile paging telephone  1  and a decoder  115  which determines if the received pager number coincides with the one stored in the pager number memory  114 . 
     The mobile phone portion  120  comprises an antenna  121 , a receiver filter  122  for cutting off unnecessary frequencies from the received signal, a demodulator  123  for demodulating a passed high frequency signal into a base band signal, a modem (or modulator/demodulator)  124  for demodulating control data in the base band signal into a digital signal and modulating a digital control signal into the base band signal, an audio processor  125  for performing bidirectional conversions between a base band signal and a speech signal, a modulator  126  for converting the base band signals from the modem  124  and the audio processor  125  into a high frequency signal, a transmitter filter  127 , a receiver  128  for providing a speech output from the audio processor  125  output, and a microphone (MIKE)  129  for converting a speech input into the speech signal to the audio processor  125 . 
     The controller  100  may be any suitable microcomputer and preferably comprises a CPU (central process unit)  101 , a ROM (read only memory)  102  for storing program modules as detailed later, a RAM (random access memory)  103 , and a nonvolatile memory  104  for storing various data as detailed later. 
     Referring now to FIGS. 2 and 3, operation of the mobile paging telephone  1  of FIG. 1 will be described in the following. FIG. 2 is a diagram showing how a page message and a call back messages are routed and FIG. 3 is a diagram showing exemplary structures of the page message and the call back message used in the illustrative embodiment of the invention. It is assumed that a caller has placed a call addressed to the mobile paging telephone  1  with a communication text “CALL ME BACK IMMEDIATELY” from a telephone. Then, a page message  300  of FIG. 3 containing the communication text is transmitted from the caller&#39;s telephone to a paging station (path T 1 ) and then from the paging station to the mobile paging telephone  1  (path T 2  ) as shown in FIG.  2 . (If the caller has placed the call from a pager, then the page message  300  is transmitted from the caller&#39;s pager to the paging station through path P 1  and from the paging station to the mobile phone  1  through path P 2  as shown in broken lines in FIG. 2.) The page message  300  comprises a pager number  301  assigned to the telephone  1 , the communication text (COMMU. TEXT)  302  (“CALL ME BACK IMMEDIATELY” in this example) and a caller ID. As is well known, the page message  300  is received by the antenna  111 , selected by the FM tuner  112 , demodulated by the demodulator  113 , and tested, to see if the pager number  301  matches one stored in the page No. memory  114 , by the decoder  115 , which then passes the communication text  302  and the caller ID  303  to the controller  100  to report thereto a page message reception. 
     FIG. 4 is a flow chart of a program module stored in ROM  102  and executed by CPU  101  when CPU  101  or the controller  100  receives the communication text  302  and the caller ID  303  from the paging receiver portion  110 . In FIG. 4, the controller  100  activates the sounder/vibrator  150  to alert the user of the mobile phone  1  and starts an alert timer (not shown) which determines the duration of alert operation in step  400 ; stores and displays the received communication text  302  in RAM  103  and on the display  140 , respectively and also stores the current time in RAM  103  as a time stamp and displays the time in step  402 . 
     According to the invention, the mobile paging telephone is provided with a call number table stored in the nonvolatile memory  104 . FIG. 5 shows a call number table  500  which contains information on a call back destination associated with each of prospective callers. As shown in FIG. 5, each of the records of the table  500  comprises a caller ID  501  field, a name  502  field, a call number  503  field, and a field which contains a type code  504  of the caller&#39;s telephone or pager. The user of the mobile phone  1  preferably asks each of his or her prospective callers the call number  503  and the type (i.e., the manufacturer and the model name)  504  of a pager or a device with a text communication capability which the prospective caller wants the user to call, enters the obtained information in the table  500  associating the information with a caller ID or number  501 , and lets each prospective caller know his or her ID  501 . For example, for a prospective caller Tom Jackson, the user stores his name, a call number 012-345-6789 and a type code as a record “01”, and similarly stores Bill Johnson, 123-456-7890 and X2 as a record “02”. 
     Returning now to FIG. 4, CPU  101  searches the caller ID field of the call number table  500  for the caller ID  303  which has been received from the paging receiver portion  110 . If the search is successful or the test result of step  404  is YES, then CPU  101  may optionally display the name  502  and/or the call number  503  of the caller derived from the found record of the caller ID  303  in the call number table  500  in step  406 . An example of thus displayed screen is shown in FIG.  7 . 
     If the user or called party has pressed a predetermined key, say, an acknowledge key (not shown) of the control switch  130  while the sounder/vibrator  150  is active (the test result of step  408  is YES), then CPU  101  displays prepared response messages (not shown), prompts the user to select one of the displayed response message and press a predetermined button (not shown) of the control switch  130  in step  410 . Then, CPU  101  transmits a call back message containing the selected response message as a return communication text,  310  as shown in FIG. 3, to the call number  503  associated with the caller ID  303  in the call number table  500  in step  412 , and ends the process. 
     If the alert timer (not shown) which has been started in step  400  has expired without the acknowledge key (not shown) of the control switch  130  being pressed (decision step  416 ), then CPU  101  registers the page message  300  in memory  104  as a pending call in step  418  so as to let the user know later that there is a page message which has not been answered by the user. If the caller ID  303  is not found in step  404 , then CPU  101  displays to this effect in step  420 , and waits for user&#39;s operation for a predetermined period of time in step  422 . After step  418  or  422 , CPU  101  ends the process. 
     The call back message  310  transmitted in step  412  is shown in FIG.  3 . As shown, the call back message  310  comprises a caller&#39;s or destination call number  311  which has been derived from the call number  503  field of a record with the caller ID value =the caller ID  303  in the call number table  500 , a guidance stop code  312  for stopping the guidance for prompting user&#39;s operations which is sent from the paging station of FIG. 2, a message shift-in code  313  which indicates the start of a series of return communication texts, the series of return communication texts  350  at least including one of the prepared response messages which has been selected by the user, and an end code  314  which indicates the end of the series of return communication texts  350 . It is noted that the format of a part of the call back message  310  beginning with the guidance stop code  312  and ending with the end code  314  differs depending on the type of destination text communication set such as a pager, mobile phone. For this reason, the compilation of a call back message  310  in step  412  is achieved in accordance with the type  504  associated with the called ID  303 . 
     FIG. 6 is a diagram showing examples of the return communication texts  350  in detail. In FIG. 6, the return communication texts  350  preferably comprise a prepared response message (i.e., a selected one of the prepared response messages)  351 , a paged time or a time which has been stamped when CPU  101  received the page message  300 , the name of the user, etc. 
     If the call back message  310  is transmitted in step  412 , the message  310  is transmitted from the present telephone  1  to the cellular base station (through the radio communication path T 3 ) and from the cellular base station to the paging station (through the communication path T 4 ) as shown in FIG.  2 . The paging station in turn transmits a call back message  320  of FIG. 3 to the destination or caller&#39;s pager through the radio communication path T 5 . The call back message  320  only comprises the caller or destination call number  311  and the return communication texts  350 . In this way, the caller can receive the prepared response message  351 , a paged time  352 , the name of the called party (or the user of the mobile paging telephone  1 ) and so on, and accordingly can be at least informed of the reception of the page message  300  by the called party, the reception time and a brief message from the called party. 
     (It is noted that if the call back destination is a caller&#39;s telephone in step  412 , then the call back message  320  is transmitted from the mobile phone  1  to the cellular base station through path P 3  and from the cellular base station to the caller&#39;s telephone through path P 4  as shown in broken lines in FIG. 2.) 
     The operation of transmitting the call back message  310  in step  412  will be discussed in detail taking into account a mobile phone portion  120  busy state, an out-of- service area state and a paging station busy state in the following. FIG. 8 is a flow chart of a program module  412   a  stored in ROM  102  and executed in place of step  412  of FIG.  4 . In FIG. 8, after step  410  of FIG. 4, CPU  101  starts executing the module  412   a  with step  800 , where CPU  101  makes a test to see if the mobile phone portion  120  is busy. The test is repeated till the test result in step  800  becomes NO. When this happens, CPU  101  proceeds to step  802 , where CPU  101  makes another test to see if the mobile paging telephone  1  is within the service area. If not, then CPU  101  starts a busy timer in step  804  and makes a test in step  806  to see if the busy timer has expired. If not, CPU  101  repeats step  806 . If the test result is YES in step  806 , CPU  101  returns to step  800 . If the telephone  1  is within the service area in step  802 , then CPU  101  starts the transmission operation of step  412  in step  808  and makes a test in step  810  to see if the paging station is busy. If so, then CPU  101  cuts the mobile phone  120  in step  812  and returns to step  800  after waiting for a time period timed by the above mentioned busy timer in steps  804  and  806 . Otherwise, CPU  101  completes the transmission operation  412  in step  814 , and cuts the mobile phone  120  in step  816 , ending this program module  412   a  and accordingly ending the main process of FIG.  4 . 
     As seen from the foregoing, once the user selects one of the prepared response messages and presses a predetermined button, even if the situation is in a mobile phone  120  busy state, an out-of-service area state and/or a paging station busy state, a transmission operation for the call back message is repeatedly attempted till all of the above mentioned states are resolved. This assures the caller of the reception of call back message. 
     However, the electric field may not be sufficiently strong even if the test result is YES in step  802  when the user have just entered the service area. This may degrade the communication quality. In order to avoid this, a wait routine is preferably inserted between steps  802  and  808  as shown in FIG. 9, which is identical to FIG. 8 except that a wait routine  900  comprising steps  902  and  904  has been inserted between steps  802  and  808 . In FIG. 9, after step  802 , CPU  101  starts a level timer in step  902  and makes a test in step  904  to see if the level timer has been expired. If not, then CPU returns to step  800 . If the test result in step  904  is YES, then CPU  101  proceeds to step  808 , thereafter following the same flow as that of FIG.  8 . 
     Alternatively, the wait routine  900  may be replaced with a level check step as shown in FIG.  10 . In level check step  900   a  of FIG. 10, CPU  101  makes a test to see if the electric field is equal to or larger than a predetermined value K. In this way, the transmission of call back message is ensured according to the principles of the invention. 
     Although the invention has been described in detail with respect to specific embodiments, various modifications can be made without departing from the scope of the invention. For example, the invention has been described in conjunction with a mobile phone with a paging receiver. However, the invention is applicable to any information terminal which includes a mobile phone function and a text message communication function. 
     The above described prepared response messages may comprise not only response messages having been prepared by the manufacturer but also one(s) defined by the user. 
     The above mentioned busy, level and other timers can be set for desired expiration values by the user. However, the counters has been preferably set for respective default expiration values by the manufacturer. 
     It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.