Abstract:
An apparatus and method is disclosed for storing and accessing wireless device e-mail attachments. Some wireless devices (such as basic cell phones) have insufficient memory and processing power to read e-mail attachments. Prior art e-mail systems delete e-mail attachments if a wireless device is not capable of receiving attachments to an e-mail message. The present invention prevents the loss of e-mail attachments by storing the e-mail attachments in an e-mail attachment database for later retrieval by the recipient of the e-mail message. The present invention notifies the recipient of the location of the e-mail attachments with an e-mail attachment notification message that contains a network address and password.

Description:
TECHNICAL FIELD OF THE INVENTION  
         [0001]    The present invention is directed, in general, to wireless networks and, more specifically, to a system for delivering an electronic mail (e-mail) message to a wireless mobile station using a short messaging service (SMS) message and storing attachments to the e-mail at a separate location so that the e-mail attachments may be later retrieved by the operator of the wireless mobile station.  
         BACKGROUND OF THE INVENTION  
         [0002]    The radio frequency (RF) spectrum is a limited commodity. Only a small portion of the spectrum can be assigned to each communications industry. The assigned spectrum, therefore, must be used efficiently in order to allow as many frequency users as possible to have access to the spectrum. Multiple access modulation techniques are some of the most efficient techniques for utilizing the RF spectrum. Examples of such modulation techniques include time division multiple access (TDMA), frequency division multiple access (FDMA), and code division multiple access (CDMA).  
           [0003]    In order to attract and retain subscribers, wireless service providers frequently introduce end-user services that are desirable to consumers. These end-user services may include e-mail and web browsing provided via the wireless network. In mobile stations that have relatively large memory capacity and processing power, such as a laptop computer, implementing end-user services is a straightforward procedure.  
           [0004]    However, conventional e-mail service requires that the mobile station have both Transmission Control Protocol/Internet Protocol (TCP/IP) capability and Simple Mail Transfer Protocol (SMTP) capability. Unfortunately, both TCP/IP and SMTP require a large amount of memory and high processing capability. As a practical matter, this means that many conventional cell phones, personal digital assistants (PDAs) and pagers are unable to support a conventional e-mail program, such as Microsoft Outlook or Eudora, because of the small memory and limited processing power of these devices.  
           [0005]    These types of devices usually have sufficient memory and processing power to receive short messaging service (SMS) messages. When a sender wants to send an SMS message to a cell phone, the sender sends an e-mail to the cell phone using an artificial e-mail address such as&lt;phone number&gt;@&lt;domainname.com&gt;. The service provider network intercepts this message and copies the contents of the body of the e-mail message into the body of an SMS message. Any attachments to the e-mail are removed and ignored. The service network provider then delivers the SMS message to the cell phone.  
           [0006]    The primary disadvantage of this method is that the e-mail attachments are not delivered. Many e-mail attachments are written using a word processor (e.g., Microsoft Word or Corel Word Perfect) and are too large to be read on a cell phone. The presently available SMS systems, however, generally delete all e-mail attachments, regardless of the size of the e-mail attachment.  
           [0007]    There is therefore a need in the art for an improved system and method for delivering e-mail messages to a wireless mobile station so that e-mails attachments to the e-mail messages are not deleted and lost.  
         SUMMARY OF THE INVENTION  
         [0008]    To address the above-discussed deficiencies of the prior art, it is a primary object of the present invention to provide, for use in a wireless network, a system and method for delivering e-mail messages to a wireless mobile station so that e-mail attachments to the e-mail messages are not deleted and lost.  
           [0009]    The apparatus of the present invention comprises a short messaging service (SMS) controller coupled to the wireless network. The SMS controller is capable of receiving at least one e-mail attachment and storing the e-mail attachment for later retrieval by an operator of a wireless mobile station. The apparatus further comprises an e-mail attachment database coupled to the SMS controller. The e-mail attachment database comprises a plurality of storage sites for storing e-mail attachments.  
           [0010]    When the SMS controller receives an e-mail message from the wireless network, the SMS controller (1) converts the e-mail text into an SMS text, (2) stores the e-mail attachment in the e-mail attachment database, (3) generates an e-mail user name and e-mail password, (4) and generates an attachment notification message (containing the user name, the password, and the network address of the stored e-mail information). The SMS controller then sends the SMS text and the attachment notification message to the wireless mobile station.  
           [0011]    The operator of the wireless mobile station reads the SMS text and the attachment notification message. Then the operator of mobile station is then able to subsequently retrieve the e-mail attachment from the e-mail attachment database using an attachment retrieving device (such as a personal computer).  
           [0012]    It is an object of the present invention to provide an improved system and method for storing e-mail attachments in an e-mail attachment database so that an operator of a wireless mobile station can access and retrieve the e-mail attachments at his or her convenience.  
           [0013]    It is a further object of the present invention to provide an improved system and method for providing information to an operator of a wireless mobile station concerning the location of e-mail attachments and how the operator can access and retrieve the e-mail attachments.  
           [0014]    It is also an object of the present invention to provide an improved system and method for providing an attachment notification message that contains identification information, a user name, a password, and a network address assigned to an e-mail attachment of an e-mail message.  
           [0015]    The foregoing has outlined rather broadly the features and technical advantages of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they may readily use the conception and the specific embodiment disclosed as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.  
           [0016]    Before undertaking the DETAILED DESCRIPTION OF THE INVENTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior uses, as well as to future uses, of such defined words and phrases.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, wherein like numbers designate like objects, and in which:  
         [0018]    [0018]FIG. 1 illustrates exemplary wireless network according to an advantageous embodiment of the present invention;  
         [0019]    [0019]FIG. 2 illustrates the exemplary wireless network shown in FIG. 1 coupled to a short messaging service (SMS) controller and attachment database that are capable of receiving and re-formatting an e-mail having an e-mail attachment, delivering the e-mail to a destination mobile station as an SMS message, and storing the e-mail attachment for later retrieval in accordance with to the principles of the present invention;  
         [0020]    [0020]FIG. 3 illustrates in greater detail the short messaging service (SMS) controller and the attachment database shown in FIG. 2 according to an advantageous embodiment of the present invention; and  
         [0021]    [0021]FIG. 4 is a flow diagram illustrating the operation of the short messaging service (SMS) controller and the attachment database according to an advantageous embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]    [0022]FIGS. 1 through 4, discussed below, and the various embodiments used to describe the principles of the present invention in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the invention. Those skilled in the art will understand that the principles of the present invention may be implemented in any suitably arranged wireless network.  
         [0023]    [0023]FIG. 1 illustrates exemplary wireless network  100  according to one embodiment of the present invention. Wireless network  100  comprises a plurality of cell sites  121 - 123 , each containing one of the base stations, BS  101 , BS  102 , or BS  103 . Base stations  101 - 103  communicate with a plurality of mobile stations (MS)  111 - 114  over, for example, code division multiple access (CDMA) channels. Mobile stations  111 - 114  may be any relatively small wireless devices, including conventional cellular radiotelephones, Personal Communications System (PCS) handset devices, personal digital assistants, or the like.  
         [0024]    Dotted lines show the approximate boundaries of the cell sites  121 - 123  in which base stations  101 - 103  are located. The cell sites are shown approximately circular for the purposes of illustration and explanation only. It should be clearly understood that the cell sites may have other irregular shapes, depending on the cell configuration selected and natural and man-made obstructions.  
         [0025]    As is well known in the art, cell sites  121 - 123  are comprised of a plurality of sectors (not shown), each sector being illuminated by a directional antenna coupled to the base station. The embodiment of FIG. 1 illustrates the base station in the center of the cell. Alternate embodiments position the directional antennas in corners of the sectors. The system of the present invention is not limited to any one cell site configuration.  
         [0026]    In one embodiment of the present invention, BS  101 , BS  102 , and BS  103  comprise a base station controller (BSC) and one or more base transceiver subsystems (BTS). Base station controllers and base transceiver subsystems are well known to those skilled in the art. A base station controller is a device that manages wireless communications resources, including the base transceiver stations, for specified cells within a wireless communications network. A base transceiver subsystem comprises the RF transceivers, antennas, and other electrical equipment located in each cell site. This equipment may include air conditioning units, heating units, electrical supplies, telephone line interfaces, and RF transmitters and RF receivers. For the purpose of simplicity and clarity in explaining the operation of the present invention, the base transceiver subsystem in each of cells  121 ,  122 , and  123  and the base station controller associated with each base transceiver subsystem are collectively represented by BS  101 , BS  102  and BS  103 , respectively.  
         [0027]    BS  101 , BS  102  and BS  103  transfer voice and data signals between each other and the public switched telephone network (PSTN) (not shown) via communication line  131  and mobile switching center (MSC)  140 . BS  101 , BS  102  and BS  103  also transfer data signals, such as packet data, with the Internet (not shown) via communication line  131  and packet data serving node (PDSN)  150 . Line  131  also provides the connection path to transfers control signals between MSC  140  and BS  101 , BS  102  and BS  103  used to establish connections for voice and data circuits between MSC  140  and BS  101 , BS  102  and BS  103 .  
         [0028]    Communication line  131  may be any suitable connection means, including a T1 line, a T3 line, a fiber optic link, a network packet data backbone connection, or any other type of data connection. Line  131  links each vocoder in the BSC with switch elements in MSC  140 . Those skilled in the art will recognize that the connections on line  131  may provide a transmission path for transmission of analog voice band signals, a digital path for transmission of voice signals in the pulse code modulated (PCM) format, a digital path for transmission of voice signals in an Internet Protocol (IP) format, a digital path for transmission of voice signals in an asynchronous transfer mode (ATM) format, or other suitable connection transmission protocol. Those skilled in the art will recognize that the connections on line  131  may provide a transmission path for transmission of analog or digital control signals in a suitable signaling protocol.  
         [0029]    MSC  140  is a switching device that provides services and coordination between the subscribers in a wireless network and external networks, such as the PSTN or Internet. MSC  140  is well known to those skilled in the art. In some embodiments of the present invention, communications line  131  may be several different data links where each data link couples one of BS  101 , BS  102 , or BS  103  to MSC  140 .  
         [0030]    In the exemplary wireless network  100 , MS  111  is located in cell site  121  and is in communication with BS  101 . MS  113  is located in cell site  122  and is in communication with BS  102 . MS  114  is located in cell site  123  and is in communication with BS  103 . MS  112  is also located close to the edge of cell site  123  and is moving in the direction of cell site  123 , as indicated by the direction arrow proximate MS  112 . At some point, as MS  112  moves into cell site  123  and out of cell site  121 , a hand-off will occur.  
         [0031]    As is well known, the hand-off procedure transfers control of a call from a first cell site to a second cell site. As MS  112  moves from cell  121  to cell  123 , MS  112  detects the pilot signal from BS  103  and sends a Pilot Strength Measurement Message to BS  101 . When the strength of the pilot transmitted by BS  103  and received and reported by MS  112  exceeds a threshold, BS  101  initiates a soft hand-off process by signaling the target BS  103  that a handoff is required as described in TIA/EIA IS-95 or TIA/EIA IS-2000.  
         [0032]    BS  103  and MS  112  proceed to negotiate establishment of a communications link in the CDMA channel. Following establishment of the communications link between BS  103  and MS  112 , MS  112  communicates with both BS  101  and BS  103  in a soft handoff mode. Those acquainted with the art will recognize that soft hand-off improves the performance on both forward (BS to MS) channel and reverse (MS to BS) channel links. When the signal from BS  101  falls below a predetermined signal strength threshold, MS  112  may then drop the link with BS  101  and only receive signals from BS  103 . The call is thereby seamlessly transferred from BS  101  to BS  103 .  
         [0033]    The above-described soft hand-off assumes the mobile station is in a voice or data call. An idle hand-off is a hand-off of a mobile station, between cells sites, that is communicating in the control or paging channel.  
         [0034]    According to the principles of the present invention, wireless network  100  is capable of receiving e-mails directed to selected ones of mobile stations  111 - 114 .  
         [0035]    [0035]FIG. 2 illustrates how the present invention operates in conjunction with wireless network  100  to receive and re-format an e-mail having an e-mail attachment for delivery to a mobile station using a short messaging service (SMS) message. In the exemplary embodiment shown in FIG. 2, wireless network  100  comprises service provider network  100 . Service provider network  100  is capable of sending an e-mail message to mobile station  111  (MS  111 ) through base station  101  (BS  101 ). Service provider network  100  is coupled to the Internet  220 . It is understood that Internet  220  is merely one example of a communications network and that the present invention is not restricted to be used only with Internet  220 . It is understood that the principles of the present invention may be used in conjunction with any type of communications network.  
         [0036]    As shown in FIG. 2, exemplary e-mail sending device  210  is coupled to Internet  220 . A user who desires to send an e-mail message to mobile station  111  (MS  111 ) sends the e-mail message from e-mail sending device  210  through Internet  220  to service provider network  100 .  
         [0037]    Service provider network  100  then sends the e-mail to short messaging service (SMS) controller  230  that is coupled to service provider network  100 . SMS controller  230  comprises a communications network server or other similar type of computerized data processing system. Attachment database  240  is coupled to SMS controller  230 . As will be more fully described, if SMS controller  230  determines that the e-mail has an e-mail attachment, SMS controller  230  stores the e-mail attachment (and the e-mail text) in attachment database  240 . SMS controller  230  then assigns identification information (e.g., a number or string identifier) to the e-mail attachment so that the e-mail attachment may be accessed and retrieved from attachment database  240  at a later time.  
         [0038]    SMS controller  230  then copies the text of the e-mail into the body of an SMS message. SMS controller  230  then creates an attachment notification message and adds the attachment notification message to the SMS message. The attachment notification message informs the operator of mobile station  111  that an e-mail attachment accompanied the e-mail message and that the e-mail attachment can be accessed and retrieved from attachment database  240  by using the identification information.  
         [0039]    SMS controller then sends the SMS message to mobile station  111 . The operator of mobile station  111  reads the SMS message on display screen  260  of mobile station  111 . At a later time the operator of mobile station  111  may use an attachment retrieving device  250  (e.g., a personal computer  250 ) coupled to Internet  220  to access and retrieve the attachment from attachment database  240 .  
         [0040]    In this manner the operator of mobile station  111  has access to all e-mail attachments that are attached to his or her e-mails. Unlike prior art systems that discard e-mail attachments, the present invention preserves the e-mail attachments for later access and retrieval.  
         [0041]    [0041]FIG. 3 illustrates short messaging service (SMS) controller  230  and attachments database  240  in greater detail according to one embodiment of the present invention. In FIG. 3, SMS controller  230  comprises a conventional data processor  230  that receives incoming e-mail messages from service provider network  100  and transmits outgoing SMS messages to service provider network  100 . Attachments database  240  stores E-mail-to-SMS conversion program  310 , which is executed by data processor  230 . In an alternative embodiment, E-mail-to-SMS conversion program  310  may be stored within data processor  230 .  
         [0042]    Attachments database  240  also stores N e-mail records, including exemplary e-mail records  320 ,  330 ,  340  and  350 . E-mail record  320  is arbitrarily labeled E-Mail Record 1, e-mail record  330  is arbitrarily labeled E-Mail Record 2, e-mail record  340  is arbitrarily labeled E-Mail Record 3, and e-mail record  350  is arbitrarily labeled E-Mail Record N.  
         [0043]    Exemplary e-mail record  320  comprises SMS text data field  321 , username data field  322 , password data field  323 , and attachment data field  324 . SMS text data field  321  is arbitrarily labeled SMS Text 1. Username data field  322  is arbitrarily labeled Username 1. Password data field  323  is arbitrarily labeled Password 1. Attachment data field  324  is arbitrarily labeled Attachment 1. Attachment 1 has a starting address labeled Address 1 in FIG. 3. Exemplary e-mail records  330 ,  340  and  350  contain the same data fields for their respective e-mail messages.  
         [0044]    Assume that SMS controller  230  receives an incoming e-mail from service provider network  100  to be delivered to mobile station  111 . SMS controller  230  accesses E-mail-to-SMS conversion program  310  in attachment database  240  and converts the text of the e-mail to an SMS message. SMS controller  230  stores the SMS message text in SMS text data field  321  of E-mail record  320  (E-mail Record 1). SMS controller  230  stores the e-mail attachment in attachment data field  324  (Attachment 1) of E-mail record  320 . SMS controller  230  records the address (Address 1) of attachment data field  324  (Attachment 1).  
         [0045]    SMS controller  230  then assigns identification information (e.g., a number or string identifier) to the e-mail attachment so that the e-mail attachment may be later accessed and retrieved from e-mail record  320  of attachment database  240 . In one advantageous embodiment the identification information may take the form of a user name stored in username data field  322 . For security purposes, SMS controller  230  may assign a password for the user to use to access e-mail record  320 . The password for e-mail record  320  is stored in password data field  323 .  
         [0046]    If the e-mail received by SMS controller  230  contains more than one e-mail attachment, then SMS controller  230  stores each additional e-mail attachment (and associated information concerning location and access) in one of the other e-mail record locations available (i.e., e-mail record  330  (E-mail Record 2) through e-mail record  350  (E-mail Record N)). In one advantageous embodiment of the present invention, the user name and the password may be the same for each e-mail attachment that is attached to one e-mail.  
         [0047]    After SMS controller  230  has re-formatted the incoming e-mail message and e-mail attachment as described above, SMS controller  230  prepares an outgoing SMS message to be sent to mobile station  111 . SMS controller  230  first places the SMS version of the e-mail text (from SMS text data field  321 ) into the outgoing SMS text message. SMS controller  230  then places the following information in the outgoing SMS text message: (1) User name from username data field  323 , (2) Password from password data field  323 , and (3) Address 1 of attachment data field  324 .  
         [0048]    SMS controller  230  also generates a message for the operator of mobile station  111  that explains that an e-mail attachment that had been attached to the e-mail has been stored for later retrieval by the operator. This explanatory message is also placed within the SMS text message. Then SMS controller  230  sends the SMS text message to mobile station  111  through service provider network  100 .  
         [0049]    The operator of mobile station  111  receives the SMS text message and the accompanying attachment notification message. The operator of mobile station  111  subsequently uses the information in the SMS text message to access and retrieve the e-mail attachment (or e-mail attachments) from attachment database  240  using attachment retrieving device  250  (e.g., a personal computer).  
         [0050]    In some instances the operator of mobile station  111  may have an attachment retrieving device  250  that has sufficient storage and processing power to receive e-mail attachments that is already connected to service provider network  100 . In those instances, the operator of mobile station  111  may make prior arrangements for SMS controller  230  to simultaneously send the SMS text message together with the e-mail (and the e-mail attachments) directly to the e-mail address of attachment retrieving device  250 .  
         [0051]    In one advantageous embodiment of the present invention, SMS controller  230  and attachment database  240  are accessible at a website of server provider network  100 . In another advantageous embodiment of the present invention, SMS controller  230  and attachment database  240  are accessible at a File Transfer Protocol (FTP) site of server provider network  100 .  
         [0052]    The website or FTP site must provide an interface for the operators of the mobile stations to delete e-mail attachments from attachment database  240 . Otherwise, the number of e-mail attachment files would continue to grow until attachment database  240  was full. To solve this problem the service provider sets a “maximum database usage” policy for e-mail attachments located on attachment database  240 . Under a “maximum database usage” policy, if an operator of a mobile station exceeds his or her allotted disk storage on attachment database  240 , then no additional e-mail attachments will be stored. The additional e-mail attachments will be lost.  
         [0053]    Alternatively, the “maximum database usage” policy may be directed to the sender of the e-mails (and not to the recipient). In this alternative embodiment of the present invention, the e-mail attachments are stored in attachment database  240  in disk storage locations that are allocated to the sender. The recipient of the e-mails (i.e., the operator of a mobile station) would be able to receive information allowing him or her to retrieve e-mail attachments from the sender&#39;s memory locations on attachment database  240 . If the sender exceeds his or her allotted disk storage on attachment database  240 , then no additional e-mail attachments will be stored. The additional e-mail attachments will be lost. In this case, the website or FTP site must provide an interface for the senders of the e-mails to delete e-mail attachments from attachment database  240 .  
         [0054]    [0054]FIG. 4 is a flow diagram illustrating an exemplary method of operation of SMS controller  230  and attachment database  240  according to an advantageous embodiment of the present invention. The steps of the method are collectively referred to with reference numeral  400 .  
         [0055]    In the method shown in FIG. 4E-mail sending device  210  sends a new e-mail message to mobile station  111  at an artificial e-mail address (step  405 ). The artificial e-mail address comprises a telephone number and a domain name (here, domainname.com). Service provider network  100  receives the e-mail message and sends it to SMS controller  230  (step  410 ). SMS controller  230  receives the e-mail message and parses it as follows: (1) the e-mail text is converted into an SMS text, (2) the e-mail attachment is stored in attachment database  240 , (3) an e-mail user name and e-mail password are generated, (4) an attachment notification message (comprising the user name, the password, and the network address of the stored e-mail information) is added to the SMS text (step  415 ).  
         [0056]    Then SMS controller  230  sends the SMS text to mobile station  111  (step  420 ). The operator of mobile station  111  reads the SMS text and the attachment notification information that it contains (step  425 ). Then the operator of mobile station  111  subsequently retrieves the e-mail attachment from attachment database  240  using attachment retrieving device  250  (step  430 ).  
         [0057]    Although the present invention has been described in detail, those skilled in the art should understand that they could make various changes, substitutions and alterations herein without departing from the spirit and scope of the invention in its broadest form.