BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates generally to messaging and more particularly to a universal messaging center or mailbox that notifies subscribers of any type of message that is waiting for them, for example, voice mail, fax mail, e-mail, etc., and allows subscribers to retrieve and respond to the messages in formats independent not only of each other but also of the format in which the message was originally transmitted.  
           [0002]    The trend in the telecommunications industry is toward providing a wide variety of information and communication services, or messaging services, over various communications networks to remote subscribers having diverse analog and digital communications equipment. These messaging services might include voice messaging, facsimile messaging, electronic mail, electronic document interchange, interactive voice response, audio text, speech synthesis, speech recognition, video messaging, video mail, etc.  
           [0003]    To provide these messaging services, different types of communications equipment and processing protocols connect to a single host system or messaging center that provides the messaging services. The messaging center performs protocol conversions between the format employed by the messaging center and the various telecommunications formats employed by the diverse subscriber equipment.  
           [0004]    Companies that provide messaging services over the public telephone network traditionally use hardwired transceiving and protocol conversion equipment dedicated to a particular type of equipment and communications format and protocol. Unfortunately, this approach suffers from high costs and lack of flexibility and adaptability. The disadvantages arise because dedicated hardware cannot be readily modified to increase data throughput, or handle communication protocols from new telecommunications equipment or services. Supporting multiple types of messaging services for diverse communications equipment thus requires costly module replacements and new designs for dedicated hardware.  
           [0005]    Recently, some developers have proposed digital signal processing and multimedia interfaces to process the communication trunk lines. For example, U.S. Pat. No. 5,497,373 to Hulen et al. describes a system with a host messaging center that supports numerous types of messaging applications and makes the necessary protocol conversions for different telecommunications protocols corresponding to various types of telecommunications media. The system uses multiple digital signal processors to perform real time protocol conversions between the different telecommunication protocols and the protocol of the host messaging center.  
           [0006]    [0006]FIG. 1 is a block diagram showing how Hulen et al.&#39;s messaging system might connect to multimedia subscribers through various public and private communications networks  1100 , including, for example, a public switched telephone network (PSTN), a public cellular or mobile telephone network (PLMN), and a packet switched public data network (PSPDN). The messaging system includes telephony front end equipment  1200 , multimedia interface  1300 , and host messaging center  1400 .  
           [0007]    Telephony front end  1200  interfaces to communications networks  1100  and provides the necessary interface between a subscriber&#39;s voice or data channel from communications network  1100  and the messaging system. Multimedia interface  1300  performs protocol conversions of the information received in various telecommunications formats so host messaging center  1400  can process and store the information in the host&#39;s data processing and storage format, typically a compressed data format.  
           [0008]    Once converted, host messaging center  1400  processes the relevant messaging information extracted from the communications channel to deliver the particular messaging or telephony service requested by the subscriber. Multimedia interface  1300  then converts the information for responding to the subscriber&#39;s service request back into the communications protocol format used by the subscriber, and transmits the converted information to the subscriber via telephony front end  1200  and communications network  1100 .  
           [0009]    Multimedia interface  1300  includes several parallel digital signal processors dynamically allocated to handle different types of protocol conversion for multiple communications channels. Host messaging center  1400  downloads appropriate protocol conversion algorithms to selected digital signal processors depending upon the type of services required by a particular subscriber. The selected digital signal processors convert and store the information in the format of host messaging center  1400  so host messaging center  1400  can process the information according to the particular messaging service requested by the subscriber. The subscriber retrieves the information in the communications protocol format used by the subscriber.  
           [0010]    With this system, a subscriber&#39;s responses to the retrieved information were limited to only the precise formats that the information was stored and retrieved. This limited the subscriber&#39;s options to retrieve and respond to messages by not allowing use of other telecommunications equipment having different or multiple formats.  
           [0011]    Therefore, a need exists to take advantage of the capabilities of current telecommunications equipment to provide subscribers with greater flexibility in the formats of retrieval and responses to messages.  
         SUMMARY OF THE INVENTION  
         [0012]    The present invention addresses this need by providing a universal mailbox by which a subscriber can retrieve a pending message in a format independent of the format used to store the message, and respond to the message in a format independent of the format used to store or retrieve the message.  
           [0013]    In accordance with the purpose of the invention as embodied and broadly described herein, the universal mailbox according to the principles of the present invention processes messages intended for a subscriber. A caller sends a message to the message center in a first caller format. The message center stores the message in the first caller format, notifies the subscriber, and awaits a request for the stored message from the subscriber. In response to the message request, the message center sends the stored message to the subscriber in a first subscriber format independent of the first caller format.  
           [0014]    If the subscriber desires, the subscriber constructs a response to the message and sends it to the message center in a second subscriber format independent of the first caller format and the first subscriber format. The message center stores the response in the second subscriber format and sends the stored response to the caller in a second caller format independent of the first caller format and the first and second subscriber formats.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, explain the objects, advantages and principles of the invention. In the drawings,  
         [0016]    [0016]FIG. 1 is a block diagram of a conventional messaging system;  
         [0017]    [0017]FIG. 2 is a block diagram of a communications network having the universal mailbox of the present invention;  
         [0018]    [0018]FIG. 3 is a block diagram of the elements of the universal mailbox shown in FIG. 2;  
         [0019]    [0019]FIG. 4 is a block diagram of the elements of the interface shown in FIG. 3;  
         [0020]    [0020]FIG. 5 is a block diagram of the elements of the service provider shown in FIG. 3;  
         [0021]    [0021]FIG. 6 is a block diagram of the elements of the message translator shown in FIG. 3;  
         [0022]    [0022]FIG. 7 is a flow chart of a process for storing a message in the universal mailbox consistent with the principles of the present invention;  
         [0023]    [0023]FIG. 8 is a flow chart of a process for retrieving a message from the universal mailbox consistent with the principles of the present invention; and  
         [0024]    [0024]FIG. 9 is a flow chart of a process for responding to a retrieved message consistent with the principles of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]    The following detailed description of the invention refers to the accompanying drawings that illustrate preferred embodiments consistent with this invention. Other embodiments are possible and changes may be made to the embodiments without departing from the spirit and scope of the invention. The following detailed description does not limit the invention. Instead, the scope of the invention is defined only by the appended claims.  
         [0026]    In the detailed description that follows, “subscriber” refers to a person that subscribes to the services provided by the universal mailbox. The subscriber can store messages for other subscribers in the universal mailbox or retrieve messages that have been stored therein. A “caller,” on the other hand, refers to a person who does not subscribe to the universal mailbox services. The caller&#39;s actions are limited to leaving messages for subscribers. The universal mailbox consistent with the principles of the present invention permits subscribers to retrieve and respond to any type of stored message in whatever format the subscribers desire.  
         [0027]    I. System Elements  
         [0028]    [0028]FIG. 2 is a block diagram of a communications network containing the universal mailbox of the present invention. Subscribers of the universal mailbox service connect to the network via a variety of telecommunications equipment through analog, digital, and Internet lines, and wireless connections. The subscriber equipment includes, but is not limited to, group 1, 2, 3 facsimile machine  2110 , Plain Old Telephone System (POTS) telephone  2120 , Analog Display Services Interface (ADSI) telephone  2130 , group 4 facsimile machine  2140 , ISDN telephone  2150 , computer terminal  2160 , Personal Communications Services (PCS) wireless telephone  2170 , PCS mobile telephone  2180 , and analog/digital cellular telephone  2190 . ADSI telephone  2130  might include group 3 facsimile machine  2132  and printer  2134  connected thereto.  
         [0029]    End offices  2200  connect the subscriber equipment, except for Internet terminal  2160 , to the network. Group 1, 2, 3 facsimile machine  2110 , POTS telephone  2120 , and ADSI telephone  2130  connect to end offices  2200  over conventional analog lines. Group 4 facsimile machine  2140  and ISDN telephone  2150  connect over conventional digital lines. PCS wireless telephone  2170 , PCS mobile telephone  2180 , and analog/digital cellular telephone  2190  connect to end offices  2200  via conventional wireless connections.  
         [0030]    End office  2200  connects to universal mailbox  2300  by conventional mechanisms over a Public Telecommunications Network (PTN), such as a Public Switched Telephone Network (PSTN). Internet terminal  2160 , on the other hand, connects to universal mailbox  2300  by conventional mechanisms over the Internet.  
         [0031]    Universal mailbox  2300  includes a computer with conventional connections to the PTN and the Internet, and might include a UNIX-capable computer, such as an HP model or the IBM Risc  6000 .  
         [0032]    [0032]FIG. 3 is a block diagram of the elements of universal mailbox  2300 . Universal mailbox  2300  preferably includes interface  3100 , service provider  3200 , subscriber mailbox  3300 , and message translator  3400 . Interface  3100  connects universal mailbox  2300  to various telecommunications networks, including the PTN and the Internet.  
         [0033]    [0033]FIG. 4 is a block diagram of the elements of interface  3100 , including transceivers  4100 , detectors  4200 , and selectors  4300 . Transceivers  4100  interface with the various networks, including the PTN and the Internet, and exchange signals with the subscriber equipment to permit subscribers to store, retrieve, and respond to messages in universal mailbox  2300 , and to permit universal mailbox  2300  to notify the subscribers of pending messages awaiting retrieval.  
         [0034]    Detectors  4200 , which preferably include conventional signal line detectors, detect the type of telecommunications equipment a subscriber is using based upon the types of signals received by transceivers  4100 . Detectors  4200  send information indicating the equipment type to message translator  3400  and a selection signal to selectors  4300 .  
         [0035]    Selectors  4300 , which include conventional selectors, such as multiplexers/demultiplexers, route the subscriber signals received by transceivers  4100  to service provider  3200  using the selection signal from detectors  4200 , and also route notification signals to the subscribers via transceivers  4100 .  
         [0036]    Returning to FIG. 3, service provider  3200  connects to interface  3100 , subscriber mailbox  3300 , and message translator  3400 , and provides subscriber services in the various forms as the subscribers require. FIG. 5 is a block diagram of possible elements of service provider  3200 , including voice mail server  5100 , ADSI mail server  5200 , fax mail server  5300 , e-mail server  5400 , and page server  5500 .  
         [0037]    Voice mail server  5100  provides voice mail services for a subscriber, including the storage and retrieval of voice messages in subscriber mailbox  3300 .  
         [0038]    Upon receipt of a voice call, voice mail server  5100  detects information regarding the caller, such as calling line identification (CLID) data, from the voice call signal by conventional mechanisms, and stores the caller information along with the voice message in subscriber mailbox  3300 .  
         [0039]    ADSI mail server  5200  provides ADSI mail services for the subscriber, including the storage and retrieval of voice, ADSI text, and mixed voice and ADSI text messages in subscriber mailbox  3300 . Upon receipt of ADSI mail, ADSI mail server  5200  detects the caller information from the ADSI mail signal, as above, and stores the caller information along with the ADSI mail in subscriber  3300 . Fax mail server  5300 , e-mail server  5400 , and page server  5500  store and retrieve fax, e-mail, and page messages, respectively, for the subscriber in the same manner set forth above.  
         [0040]    In addition to storing and retrieving the various forms of subscriber messages, servers  5100  through  5500  also notify the subscribers of pending messages in subscriber mailbox  3300  that await retrieval. Table 1 shows examples of various forms of subscriber notification based upon the type of telecommunications equipment the subscriber uses to retrieve the pending messages.  
                                                                 TABLE 1                           RETRIEVAL DEVICE            POTS Phone   ADSI Phone   Pager   Fax   Computer                    NOTIFICATION TYPES            &gt;Phone call   &gt;Phone call   &gt;Deliver the   &gt;Deliver the   &gt;Audible or               message.   message.   visual alert       &gt;Message   &gt;Message wait-           on screen       waiting light   ing light           &gt;Deliver the       &gt;Message   &gt;Message wait-           message.       waiting tone.   ing tone           &gt;Display mes-           sage informa-           tion on screen           &gt;Download           message to           phone (for non-           voice           messages).                  
 
         [0041]    Returning to FIG. 3, subscriber mailbox  3300  preferably includes a large-capacity memory device, such as a disk array, with connections to service provider  3200  and message translator  3400 . Subscriber mailbox  3300  stores subscriber messages in the different subscriber formats. The particular formats of a pending stored message might include the format used by the caller or subscriber leaving the message and the format typically requested by the subscriber, as described below.  
         [0042]    Subscriber mailbox  3300  preferably stores the pending messages in both of these formats. Subscriber mailbox  3300  preferably also stores a database of subscriber profile data. The subscriber profile data includes subscriber-defined information regarding the subscriber&#39;s notification preferences. The subscriber profile data might include any of the notification types shown in Table 1, including notifying the subscriber using a message waiting light or tone, or by sending part or all of the message to the subscriber as the notification.  
         [0043]    The subscriber profile data could be more specific. The subscriber might associate a notification type with a specific type of telecommunications equipment.  
         [0044]    For example, the subscriber could designate notification by an ADSI text message when retrieving messages using ADSI phone  2130 . Message translator  3400  connects to subscriber mailbox  3300 , interface  3100 , and service provider  3200 , and performs translations between the various subscriber message formats. FIG. 6 is a block diagram of the elements of message translator  3400 , including controller  6100 , plain telephone translator  6200 , fax machine translator  6300 , ADSI telephone translator  6400 , computer translator  6500 , pager translator  6600 , and miscellaneous translator  6700 .  
         [0045]    Controller  6100  preferably includes a standard processor that controls the operation of translators  6200  through  6700 . For each message retrieval, controller  6100  records the type of telecommunications equipment the subscriber uses based on the subscriber equipment detected by detectors  4200  of interface  3100 . From the recorded equipment type, controller  6100  determines a normal retrieval format for each subscriber. If a subscriber typically retrieves pending messages using POTS telephone  2120 , for example, controller  6100  records the subscriber&#39;s normal retrieval format as a voice format. Controller  6100  stores the subscriber&#39;s normal retrieval format in subscriber mailbox  3300 .  
         [0046]    During idle periods, as the pending messages reside in subscriber mailbox  3300 , controller  6100  retrieves the pending messages from subscriber mailbox  3300 , translates them from the stored format to the normal retrieval format using one of the translators  6200  through  6700 , and returns the translated messages to subscriber mailbox  3300 . Translators  6200  through  6700  execute conventional translation techniques, such as described in U.S. Pat. No. 5,497,373 to Hulen et al., to perform translations from the stored format to the subscriber&#39;s normal retrieval format. Table 2 shows examples of various translations performed by translators  6200  through  6700 .  
                                                                                 TABLE 2                                       RETRIEVAL DEVICE                POTS Phone   ADSI Phone   Fax   Computer   Pager                        TRANSLATOR            Plain telephone   None.   Message   Voice to text to   Voice to sound   Message               information can   Fax graphics,   file (and to text   information               be provided in   and Message   for hearing   only.               ADSI text   information.   impaired), and               format. Voice       message               to ADSI text       information.               used for hearing               impaired               service.       Fax machine   Fax graphics   Fax graphics to   None.   Fax graphics to   Message           to text to   ADSI text.       computer   information           voice.           graphics, and   only.                       message                       information.       ADSI telephone   None for   None.   ADSI text to   ADSI text to   Message           voice. ADSI       Fax graphics.   text.   information           text to voice.               only.       Computer   Text to voice.   Text to ADSI   Text to Fax   None.   Message               text.   graphics.       information                           only.       Pager   Text to voice.   Text to ADSI   Text to Fax   None.   None.               text.   graphics.                  
 
         [0047]    II. Processing  
         [0048]    FIGS.  7 - 9  are flow charts illustrating the operation of the universal mailbox consistent with the principles of the present invention. FIG. 7 is a flow chart of a process for storing a message in universal mailbox  2300 . The process begins when a caller sends a message to a subscriber in a caller format. The caller format depends upon the type of telecommunications equipment the caller utilizes to send the message.  
         [0049]    The caller may send the message to universal mailbox  2300  or to the subscriber&#39;s telecommunications equipment. The subscriber&#39;s telecommunications equipment would then relay the message to universal mailbox  2300  by conventional mechanisms, when the subscriber is unavailable to receive the message.  
         [0050]    In any event, interface  3100  in universal mailbox  2300  receives the message from the caller in the caller format [step  7100 ], and forwards it to service provider  3200 . Service provider  3200  analyzes the message to detect information regarding the caller from the message signal, as described above. Service provider  3200  then stores the message in subscriber mailbox  3300  in the caller format along with the detected caller information [step  7200 ], and notifies the subscriber of the pending message [step  7300 ]. Service provider  3200  notifies the subscriber according to the subscriber profile data stored in subscriber mailbox  3300 . The subscriber notification may include a message waiting light or tone on the subscriber&#39;s telephone, or the message itself delivered to the subscriber&#39;s ADSI telephone, pager, fax, or computer (Table 1).  
         [0051]    Off-line, during idle periods, message translator  3400  determines the subscriber&#39;s normal retrieval format from the information stored in subscriber mailbox  3300  [step  7400 ]. When the caller format differs from the subscriber&#39;s normal retrieval format, message translator  3400  translates the message from the caller format to the subscriber&#39;s normal retrieval format [step  7500 ]. Message translator  3400  then stores the message in subscriber mailbox  3300  in the subscriber&#39;s normal retrieval format [step  7600 ], preferably without erasing the message in the caller format. As a result, subscriber mailbox  3300  stores the message in both the caller format and the subscriber&#39;s normal retrieval format.  
         [0052]    When the subscriber wants to retrieve a pending message, the process shown by the flow chart in FIG. 8 occurs. The subscriber establishes a connection between the subscriber&#39;s telecommunications equipment and universal mailbox  2300  to request retrieval of the pending message. The subscriber might accomplish this by dialing universal mailbox  2300 &#39;s telephone number, or by configuring the subscriber&#39;s telecommunications equipment to automatically establish the connection. Interface  3100  of universal mailbox  2300  receives the subscriber&#39;s request for retrieval of the pending message [step  8100 ], and detects the type of telecommunications equipment the subscriber used to make the request [step  8200 ].  
         [0053]    Because some types of telecommunications equipment permit the subscriber to retrieve the pending message in more than one form, the subscriber must specify the desired retrieval form when using these types of telecommunications equipment. For example, if the subscriber uses ADSI telephone  2130  to retrieve the pending message, the subscriber must specify whether the pending message should be downloaded in voice or ADSI text form.  
         [0054]    Interface  3100  then routes the request to service provider  3200 . Based on the detected type of subscriber telecommunications equipment and any subscriber specified retrieval format, service provider  3200  determines the subscriber&#39;s retrieval format [step  8300 ]. Service provider  3200  reads the pending message from subscriber mailbox  3300  and determines whether the message is already in the retrieval format [step  8400 ]. The message would already be in the retrieval format if the retrieval format is the same as the caller format or the subscriber&#39;s normal retrieval format. If the message is already in the retrieval format, then service provider  3200  sends the message to the subscriber [step  8500 ].  
         [0055]    If the message is not already in the retrieval format, service provider  3200  notifies message translator  3400 . Message translator  3400  reads the message from subscriber mailbox  3300  and translates the message to the retrieval format [step  8600 ]. After translation, message translator  3400  gives the message to service provider  3200 . Service provider  3200 , in turn, sends the message to the subscriber in the retrieval format [step  8700 ].  
         [0056]    If the subscriber wants to respond to the retrieved message, the subscriber must first determine what form the response should take. Table 3 shows examples of various responses permitted by some types of telecommunications equipment.  
                                                                 TABLE 3                           RETRIEVAL DEVICE            POTS Phone   ADSI Phone   Pager   Fax   Computer                    RESPONSE TYPES            &gt;Phone call.   &gt;Phone call   &gt;Message   &gt;Phone call   &gt;E-mail               information.           &gt;Text message.       &gt;Fax.   &gt;E-mail with                       voice file                       attachment.                  
 
         [0057]    Once the subscriber determines what form the response will take, the process shown by the flow chart in FIG. 9 occurs. The subscriber generates a response for the caller and sends it to universal mailbox  2300 . Interface  3100  receives the response from the subscriber in the response format [step  9100 ], and forwards it to service provider  3200 . The response format may differ from both the caller format and the retrieval format.  
         [0058]    Upon receipt of the response, service provider  3200  determines whether the caller is also a subscriber to the universal mailbox services by checking for the caller&#39;s identity in subscriber mailbox  3300  [step  9200 ]. If the caller is a subscriber, service provider  3200  stores the response in subscriber mailbox  3300  in the response format [step  9300 ], and notifies the caller of the pending response, in the manner described above [step  9400 ].  
         [0059]    Off-line, during idle periods, message translator  3400  determines the caller&#39;s normal retrieval format from the information stored in subscriber mailbox  3300  [step  9500 ]. When the response format differs from the caller&#39;s normal retrieval format, message translator  3400  translates the response from the response format to the caller&#39;s normal retrieval format [step  9600 ]. Message translator  3400  then stores the response in the caller&#39;s normal retrieval format in subscriber mailbox  3300  [step  9700 ].  
         [0060]    If the caller is not also a subscriber, service provider  3200  notifies message translator  3400 , which translates the response to the caller format, the same format as the original message sent by the caller [step  9800 ]. After translating the response, message translator  3400  returns it to service provider  3200 . Service provider then determines the location of the caller, including the caller&#39;s e-mail address, telephone number, or fax number, from the caller information stored in subscriber mailbox  3300  [step  9900 ]. Alternatively, service provider  3200  could obtain the caller&#39;s location from the subscriber. Service provider  3200  might obtain the caller&#39;s location from the subscriber when the caller information would not direct the response to the caller&#39;s correct location, for example, when the caller originally sent the message from public telecommunications equipment.  
         [0061]    Once service provider  3200  obtains the caller&#39;s correct location, service provider  3200  transmits the response to the caller in the caller format [step  10000 ].  
         [0062]    This transmission might take the form of a telephone call, a fax, an e-mail, or a page to the caller.  
         [0063]    The universal mailbox consistent with the principles of the present invention permits subscribers to retrieve and respond to messages in any format, independent of the formats used to store, retrieve, and respond to the messages.  
         [0064]    The foregoing description of preferred embodiments of the present invention provides illustrations and descriptions, but is not intended to be exhaustive nor limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The scope of the invention is defined by the claims and their equivalents.  
         [0065]    For example, Tables 1 through 3 show types of notification, translators, and responses, respectively, corresponding to various types of telecommunications equipment. These were presented as examples only and would obviously include other types of notification, translators, responses, and telecommunications equipment, taking advantage of new advancements in the art, as well as the development of new types of telecommunications equipment.  
         [0066]    Furthermore, the subscriber has been described as responding to a retrieved message using the same telecommunications equipment used to retrieve the message. This need not be the case, however. The universal mailbox consistent with the principles of the present invention permits a subscriber to respond to a pending message using a different type of telecommunications equipment than was used to retrieve the message without requiring the subscriber to retrieve the message a second time. The subscriber need only record the reference number associated with the retrieved message to inform the universal mailbox of the identity of the message to which the subscriber subsequently responds.
A messaging center, connected to a communications network, processes messages intended for a subscriber. A caller sends a message to the message center in a first caller format. The message center stores the message in the first caller format, notifies the subscriber, and awaits a request for the stored message from the subscriber. In response to the message request, the message center sends the stored message to the subscriber in a first subscriber format independent of the first caller format. If the subscriber desires, the subscriber constructs a response to the message and sends it to the message center in a second subscriber format independent of the first caller format and the first subscriber format. The message center stores the response in the second subscriber format and sends the stored response to the caller in a second caller format independent of the first caller format and the first and second subscriber formats.