Paging

Abstract: A small portable computing device (110), such as a personal digital assistant (PDA), is provided with a paging capability to assist the user of the PDA in receiving and responding to pages. One feature is the automated look-up of a telephone number received as a paged message to provide the user of the PDA with the name of the sender of the page, the telephone number of the sender and a telephone icon which, when selected by the user, will cause the PDA to dial the telephone number identified by the paging message. The device is also capable of receiving messages in a predetermined format which identifies the name of the caller as well as an alphanumeric message. The paging mechanism is also used to notify the user of electronic mail which has arrived into the user's mailbox located on an electronic mail system. In addition, when the device is in a powered down state, the pager card, upon receipt of a paging message that electronic mail has been sent to the user, wakes up the powered down computing device. The computing device responds by dialling up the electronic mail provider and retrieving the electronic mail message. In addition, an innovative memory allocation technique is used.

Description: This invention relates to paging, and more specifically to paging mechanisms, devices, interfaces and processes. More particularly, but not exclusively, the invention relates to the use of radio frequency paging devices in computer systems, for instance portable computer systems. Paging devices are widely accepted and used as a form of communication. The earliest pagers were simple receiving devices which would generate an audible tone when the user was paged. The user would then call a predetermined number to find out the message associated with the page. Typical paging devices today provide for alphanumeric paging which provides on a small display a telephone number or a short alphanumeric message. As computers have become smaller in size and therefore more portable, functions such as paging have been added to these computer devices. European Patent Application EP-A-0 434 231 discloses a portable computing device that comprises a processor, display, input device and paging mechanism. The paging mechanism includes a plug-in paging accessory or device. The computing device can compare a received phone number against a list of phone numbers to identify a person to be called in response to a page. From US-A-5 212 721 it is known to compare a received message with entries of a database containing telephone members. However, as in the above cited prior art, the database does not comprise any names. According to a first aspect of the invention there is provided a computing device comprising a processor, display, input device and paging mechanism, the paging mechanism comprising: a telephone receiving and transmitting device; a database comprising at least one name and at least one telephone number; a paging device comprising a receiver to receive a numeric message; said processor being operative to compare the numeric message to the telephone numbers in the database; if said processor determines a match between the numeric message and a telephone number in the database, said processor being operative to generate on the display a paging display comprising the name corresponding to the matched telephone number, the telephone number and a telephone button; if said processor determines no match between the numeric message and a telephone number in the database, said processor being operative to generate on the display a paging display comprising the numeric message; and if said user selects the telephone button using the input device, the telephone receiving and transmitting device being operative to dial the number displayed; wherein the user is automatically provided with the name of the person who sent the page and a telephone button to easily call back the person who sent the page. According to a second aspect of the invention there is provided, a process for providing a user interface on a computing device comprising a processor, display, input device and paging device for receiving pages, in response to receiving pages, the process comprising the steps of: receiving a numeric message; comparing the numeric message to the telephone numbers in a database comprising at least one name and at least one telephone number; if there is a match between the numeric message and a telephone number in the database, generating on the display a paging display comprising the name corresponding to the matched telephone number, the telephone number and a telephone button; and dialing the number displayed in response to the user selecting the telephone button using the input device; wherein the user is automatically provided with the name of the person who sent the page and a telephone button to easily call back the party who sent the page; and if there is no match between the numeric message and a telephone number in the database, generating on the display a paging display comprising the numeric message. Preferred embodiments of the invention and examples for facilitating the understanding of the invention described hereinbelow provide: an innovative user interface for pager functionality on a small digital computing device; automatic look-up of a telephone number provided in a paging message to identify the sender of the page and a button to enable the user to immediately call back the sender of the page; an automated electronic mail receiving system which automatically dials up an electronic mail system and down-loads messages upon receipt of the page indicating that messages are waiting in the electronic mail system; and a memory efficient paging system in which a portion of the paging system is operable without connecting the paging device to the computer system. In one embodiment, a small portable computing device, such as a personal digital assistant (PDA/PIC) or a personal communications device is provided with an innovative paging capability- to assist the user of the PDA in receiving and responding to pages. One feature is the automated look-up of a telephone number received as a paged message to provide the user of the PDA with the name of the sender of the page, the telephone number of the sender and a telephone icon which, when selected by the user, will cause the PDA to dial the telephone number identified by the paging message. In another embodiment, the PDA receives messages in a predetermined format which identifies the name of the caller as well as the alphanumeric message. The system responds by displaying the name and telephone number of the caller, the message, and an icon to enable the user to call the sender of the paging message. The paging mechanism according to an example for facilitating the understanding of the invention may also be used to notify the user of electronic mail which has arrived into the user's mailbox located on an electronic mail system. In this event, when a message is received, the electronic mail system generates a page notifying the user that there is a mail message waiting to be read. If the computing device is in a power on state, an icon appears, enabling the user to download the message from the electronic mail system by selecting the icon. The paging system responds to selection of the icon by dialling up the electronic mail system, accessing the electronic mail message, and downloading the message from the E-mail system to the computing device. In addition, it is preferred that when the device is in a power down state and a page is received, indicating that a message awaits the user, the paging device causes the computing device to go into a power on state and dial up the electronic mail system to automatically retrieve and download the message into the computing device memory for access by the user when the user subsequently turns the computing device on. Furthermore, a memory allocation technique according to a further example for understanding the invention may be provided. A portion of the paging software that provides the paging functionality in the computing device is downloaded to the memory of the computing device when the paging device is first connected to the computing device. The software downloaded includes the paging code to send out pages through the telephone transmitting and receiving device located in the computing device and software to read the display stored messages. Thus the user can remove the paging device from the computing device and still display messages and send out paging messages. The software may be generated to provide common links when needed. For example, the paging display software accesses the information stored in memory by the paging receiving software. The invention will now be further described, by way of illustrative and non-limiting example, with reference to the accompanying drawings, in which: Figure 1 is an external representation of a device embodying the invention used to provide innovative paging functions; Figure 2 is a system block diagram which may be used in the device of Figure 1 to provide the innovative paging functions; Figure 3 is an exemplary flow diagram of a process for downloading a portion of software for performing a paging function; Figure 4 is a flow diagram describing the display of paging messages and, in particular, the look-up and display of telephone numbers and callers corresponding to those telephone numbers and an icon which enables the user to immediately dial up the sender of the page; Figure 5, Figure 6, Figure 7, Figure 8, Figure 9, Figure 10, and Figure 11 illustrate exemplary generated displays; Figure 12 and Figure 13 illustrate exemplary displays generated when a paging message is received regarding E-mail messages; Figure 14a and 14b are tables which describe messages and display of phone numbers in response to pages received; and Figure 15 is a flow chart illustrating exemplary steps for receiving electronic mail messages. A portable computing device, which provides innovative paging functionality, is described. In the following description for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that these specific details are not required in order to practice the present invention. In other instances, well-known electrical structures and circuits are shown in block diagram form in order not to obscure the present description. Figure 1 is an illustrative drawing of a small computing device which includes innovative paging functions in accordance with embodiments of the invention. The device, 110, includes a display, 120, with a touch-sensitive screen, enabling the user to provide input to the device through the touch-sensitive screen. Also included are a plurality of input/output connectors 140, including a telephone jack to connect the telephone receiver and transmitting device located internal to the computing device 110 to a telephone network. This enables the device 110 to dial up and receive telephone calls. Also included is a slot 130 for receiving a memory card, such as a PCMCIA (Personal Computer Memory Card International Association) card. In the present invention, it is preferred that the paging device described herein is incorporated on a card that fits into the slot 130 and interfaces with the device 110 to provide the paging functionality described herein. An exemplary block diagram of the system is shown in Figure 2 . Processor 200, is coupled to internal memory 220, display 210, touch screen 230, and the PCMCIA slot, 245, which can receive and connect PCMCIA compatible cards such as an external memory card 250 or the pager card 240 described herein. These devices are coupled via a bus 260. Also coupled to the bus is a telephone receiving and transmitting device 270, which enables the device to communicate through the telephone network. The pager card includes a receiver to receive paging transmissions and at least one light indicator to indicate status of the paging device, such as unread messages. The card includes local nonvolatile memory for storage of the software to control the paging card. In one example for facilitating the understanding of the present invention, a portion of the software is downloaded to the computing device internal memory for access by the processor when performing pager functions. The remaining portion continues to be stored in the nonvolatile memory of the pager card and is provided to the processor when needed to execute certain paging functions. Preferably the software is downloaded into non-volatile memory such that the software is maintained in memory when the processing device is in a non-volatile state. The ability to download a portion of the pager card software provides for a number of distinct advantages. First, by downloading a portion of the software to the computing device local memory, that functionality embodied in the software is accessible without the pager card. This is important in small devices which only have one PCMCIA slot and need the memory slot for insertion of an expansion memory card. In the present example software to enable the user to send a page through the telephone network and software to display and read current paging messages previously received by the pager card are permanently downloaded to the computing device memory. The software to display paging messages includes bit mapped images of certain graphic objects used in the display. Substantial memory space is saved as the display is generated by reference to the graphic objects. The software is developed to communicate with common objects and data as needed to provide the functionality desired. For example the page receiving software receives the page and generates the list of objects to be displayed. This is communicated, for example through a common database or via a message, to the pager display software which generates the display of the page message. Figure 3 is an exemplary flow diagram of this process for downloading a portion of the software and accessing the software to provide the paging functions described herein. The flow diagram sets forth the functionality of the process. It is readily apparent to one skilled in the art that a variety of implementations may be generated using known programming techniques to perform the functionality described. Therefore, the details of such implementations will not be discussed herein. Referring to Figure 3 , when the pager card is first inserted into the device, step 300, the device detects insertion of the pager card, and if the pager software is not stored in the device memory, accesses the card memory 310 to retrieve the portion of the software to perform certain paging operations without the paging hardware. Preferably, control bits are provided in the software to tell the processor which portions of the code to download permanently to the processing device memory. The software downloaded is stored in internal memory, step 320, of the computing device. Thus, when the pager card is subsequently removed, for example in order to insert an extended memory card, step 330, certain portions of the software remain resident in the internal memory of the computing device. Therefore, selected functions are operable without the pager card. In the present example, step 340, software to send pages and software to display retrieved pages are resident in the computing device and executable without the pager card. When the pager card is subsequently reinserted, step 340, the software functionality that is only resident on the pager card is accessible. In the present example, the software to retrieve pages is stored in the pager card is executed, step 350, enabling the user to retrieve pages to be displayed on the display. The pager software, whether resident on the pager card or stored in the computing device memory, communicates information among the executing paging processes, such as paging data representative of the message received, in order to provide seemingly seamless paging operations. For example, when the pager card is inserted into the computing device and a page is received, a first process executes the pager receiving code located in the pager card and a second process executes the pager display code stored in the memory of the computing device. One way contemplated to communicate data between processes operative from the pager card and processes operative from the computing device is to provide a message transfer capability in which data is communicated using a message handling system. Another way contemplated is to provide a shared memory that all the processes access to read and write the shared data. Other data sharing/communication techniques may also be used. An additional feature is the ability to remove the pager card and limit the insertion of the card into the computing device to only when the user receives a page. Preferably, the pager card has LEDs indicating unread pages. In addition, a pager card may provide some audible mechanism to indicate unread pages. Thus, the user can remove the paging card from the device and insert another card, such as the extended memory card, to perform other operations, and when a page is subsequently received, as indicated by the visible or audible indicators on the pager card, the user can receive the page immediately by removing the memory card currently in the device and inserting the pager card to access the paging messages through the user interface of the computing device. The memory card can be subsequently reinserted once the user has read the page. An innovative user interface for receiving messages and returning telephone calls is now described. Referring to Figure 4 , one aspect of receiving pages is described. At step 400, when a page is received, the software will first determine whether the message is a numeric message or an alphanumeric message, step 410. If the message is numeric, step 412, the numbers of the message are compared to a database of names and telephone numbers to determine if the telephone number matches one contained in the user's database. This database may be a database maintained by the user, such as a telephone book, or the like. If a match is found, step 414, a display is generated identifying the person who issued the page, as determined from the database, step 416. The display further provides the telephone number of the person who issued the page and a telephone icon in the proximity of the telephone number. This icon functions as a button that is selectable by the user, step 418. If the user selects the telephone icon, step 420, the device will automatically dial, step 425, the telephone number shown next to the button to connect the user immediately to the party who issued the page. Thus the process typically exercised when receiving a page, that is to immediately call back the party who sent the page, is easily performed through the user interface of the device without the need to proceed through additional menus or displays to select a telephone dial feature. If, at step at 414, a match is not found, then the numeric message will be displayed and the user has the capability through other menus or functions on the computing device to dial the message to connect to the caller who placed the page. It is readily apparent that the interface may also provide a telephone icon with the number even though the number has not been found in the database, thereby enabling to user to automatically call the number set forth in the page. For example if the number of digits corresponds to that of a valid telephone number, the telephone button is displayed adjacent to the number, enabling the user to dial the number by selecting the button. Referring back to step 410, if the message is alphanumeric, at step 430, it is determined whether the message is in an accepted format. One such format utilized in the paging services is "sendername |subject| content". It is readily apparent to one skilled in the art that other prespecified formats may be used in accordance with the teachings of the present invention. Thus, at step 430, if the message is in an accepted format, the sendername field is compared to the name fields in the database, step 432. If a match is found, step 434, a display is generated, identifying the person who issued the page, step 436, and further providing a telephone icon and a telephone number of the person who sent the page, step 438. Therefore, if the user chooses to contact the sender of the page, step 440, the user selects the telephone icon and, at step 442, the device dials the telephone number to automatically connect the user to the person who sent the page to the user. If, at step 434, no match is found, a display is generated of the user identifying the sender, the message content and the subject of the message. Figure 5 illustrates an exemplary display 500 generated in response to receiving a numeric page consisting of a phone number which is found in the user's database. Thus, in this example, the sender of the page 510 and the telephone number 515 is identified to the user of the device. A message, 530, in the form of a note to the user, is further provided on the display to inform the user of the context of the page. In addition, the telephone number of the sender 520 is provided adjacent to a telephone icon 525. Thus, if the user wishes to call the sender of the page, he simply selects the telephone icon 525 and the device will automatically dial the telephone number. It is apparent to one skilled in the art that the icon shown in the drawings is exemplary and a variety of icons can be used to visually communicate the automatic dialing feature shown herein. Figure 6 illustrates an exemplary display when the telephone number is not found in the user's database. In this case, the sender of the page is not identified and the telephone number is provided adjacent to the telephone icon, enabling the user to contact the party who issued the page by selecting the telephone icon. In the present embodiment, as shown in Figure 7 , the telephone icon is provided if the numeric string received in the pager message is not verified to be a phone number. However, it is apparent that the system can be modified such that when a number is not in a format compatible with a telephone number, that the icon is not displayed and the user is not enabled to select the automatic telephone dialing feature. Figure 8 shows a message that was sent in the format sendername |subject| content. The database is first searched for the sendername. If a matching name is found, it is shown in the from field in its complete form as shown in the database. If it is not found in the database, the text as found in the sendername field is displayed unmodified. Thus, a partial name may be provided in the sendername field of the message and the person's complete name, as specified in the database, will show up on the display to the user. In addition, although not shown in Figure 8 , the telephone with a default telephone number for the party, may be displayed along with the message provided in the page, enabling the user to dial the sender of the page. The default number may be, for example, the party's work telephone number. It is contemplated that the default number is established for each person in the database during the generation of the database. Figure 9 illustrates a display in which no subject is provided in the subject field but the sendername and the message content is provided. Again, the database is searched for compatible sendername and displays that name in the from field of that display. Figure 10 shows an alphanumeric message in which the content of the message is a number, such as a telephone number. Thus, the number found in the message is used to compare to telephone numbers in the database to retrieve the name of the caller and the full telephone number. The telephone icon is displayed in proximity to the telephone number, indicating that the user can select the automatic dialing feature, thereby enabling the user to call the sender of the page at the identified telephone number. Figure 11 shows one possible display when the alphanumeric page is not formatted. The system responds simply by displaying the alphanumeric message sent. The structure of the database may be any data structure known to those skilled in the art which would be compatible with the device and the information to be contained in the database. For example, the database may be structured similar to a telephone directory in which the user's name, address, and telephone number is listed. More sophisticated systems would include additional fields for fax numbers and multiple telephone numbers and paging numbers. The paging functionality described herein uses the name and the telephone numbers provided for each name to do searches to identify the senders of paging messages. The system also provides a paging mechanism when electronic mail (E-mail) arrives for the user. One such E-mail service which may be used is AT&T Personal Link SM , provided by AT&T. Thus, when an E-mail message arrives, the AT&T Personal Link SM system will issue a page to the user. The page indicates that there is an E-mail message waiting for the user. Preferably, an icon will be provided that when selected, the device will automatically dial up the E-mail service and access the E-mail message that is waiting for the user. Figure 12 illustrates an exemplary selectable mail icon 1200, which enables the user to access the E-mail message. Another example for facilitating the understanding of the invention is shown in Figure 13 in which a feature button referred to as "download" is utilized to download a message from the E-mail facility. As with the receipt of the page in the predetermined format, the sendername will be compared against the database to determine the sender's full name. If a match is found, then the full name of the sender will be identified from the database. Otherwise, the name as found in the sendername field is displayed unmodified. In one example, the provider of the E-mail services is included in the user's database such that when a page comes in, the sendername will match an entry in the database for an E-mail provider. In this manner, multiple E-mail providers can be accessed automatically. If the sendername is determined to be the name of an E-mail provider, the display generated will include a message that an E-mail has arrived, the sender of the E-mail and the subject of the E-mail. This information is extracted from the prespecified string, e.g., sendername |subject| content sent as the paging message. The display will also include an electronic mail icon which functions as a button to be selected by the user. When the user selects the button, the computing device dials up the e-mail provider and retrieves the message. In another embodiment, the processor examines the incoming message string before searching the database, to determine if the message contains a code indicative that the message is from an E-mail provider. If the message is from an E-mail provider, the display of the sender and subject of the E-mail and the download button is provided. Figures 14a and 14b are tables which describe various displays that are generated in response to paging messages that are received. The left column identifies the page as received; the 'from' column identifies the sender of the page; the 'about' column identifies the subject of the page; and the 'message' is that formed from the string received. If a match is found in the database or the telephone numbers provided as part of the message, a telephone number is displayed with the telephone icon in order to enable the user to dial the sender of the page. In one example the pager provides additional functionality by retrieving a user's E-mail messages when the device is in a power down or sleep state. This process is generally described in reference to Figure 15 . Referring to Figure 15 , at step 1610, when an E-mail is received by an E-mail system, at step 1620, the E-mail system issues the page through the paging system. At step 1630, the pager receives the page indicating that E-mail is waiting for the user. The pager determines that the message is from an E-mail provider. This is preferably determined from the format of the message, for example, the sendername field. At step 1640, the pager wakes up the computing device to retrieve the E-mail. Preferably this is accomplished by the pager card issuing a wakeable interrupt signal to the computing device. The computing device is then powered up and, at step 1650, the device determines the telephone number of the E-mail provider from the page message, automatically dials the E-mail system to retrieve the E-mail and downloads the E-mail message onto the computing device such that the E-mail message is available to the user when the user subsequently accesses the computing device. At step 1660, once the download of the E-mail message is complete, the device then returns back to the sleep mode to conserve power. The invention has been described in conjunction with the preferred embodiment. It is evident that numerous alternatives, modifications, variations and uses will be apparent to those skilled in the art in light of the foregoing description.

Claims: A computing device (110) comprising a processor (200), display (210), input device and paging mechanism, the paging mechanism comprising: a telephone receiving and transmitting device (270); a database comprising at least one name and at least one telephone number; a paging device (240) comprising a receiver to receive a numeric message; said processor being operative to compare (412) the numeric message to the telephone numbers in the database; if said processor determines a match (414) between the numeric message and a telephone number in the database, said processor being operative to generate (416, 418) on the display a paging display comprising the name corresponding to the matched telephone number, the telephone number and a telephone button; if said processor determines no match between the numeric message and a telephone number in the database, said processor being operative to generate on the display a paging display comprising the numeric message; and if said user selects (420) the telephone button using the input device, the telephone receiving and transmitting device being operative to dial the number displayed; wherein the user is automatically provided with the name of the person who sent the page and a telephone button to easily call back the person who sent the page. A computing device according to claim 1, wherein said numeric message comprises a portion of a telephone number and said processor is operative to compare the portion of the telephone number to the telephone numbers in the database, such that a match can be determined between the portion of the telephone number and the telephone number in the database and the matched telephone number is displayed. A computing device according to claim 1, wherein, if said processor determines no match between the numeric message and a telephone number in the database and the numeric message comprises a number of digits corresponding to a valid telephone number, said processor is operative to generate on the display a paging display comprising the numeric message and the telephone button. A computing device according to claim 1, wherein: said processor is operative to compare an alphanumeric message received by the paging device to the names in the database; if said processor determines a match between the alphanumeric message and a name in the database, said processor is operative to generate on the display a paging display comprising the matched name; and if said processor determines no match between the alphanumeric message and a name in the database, said processor is operative to generate on the display a paging display comprising the alphanumeric message. A computing device according to claim 4, wherein said processor is operative to compare a portion of a name comprised in the alphanumeric message to the names in the database, such that a match can be determined between the portion of the name and the name in the database and the matched name is displayed. A computing device according to claim 4, wherein, if said processor determines a match between the alphanumeric message and the name in the database, said processor is operative to generate on the display the paging display of a corresponding telephone number and the telephone button to enable the user to dial the telephone number corresponding to the name. A computing device according to claim 4, wherein: in response to receipt by the paging device of an alphanumeric message in the format "sendername/subject/content", wherein sendername is the name of the party sending the page, subject is the title of the page and content is the paging message, said processor is operative to compare the sendername to the names in the database, such that if said processor determines a match between the sendername and a name in the database, said processor is operative to generate on the display a paging display comprising the matched name, subject and content; and if said processor determines no match between the sendername and a name in the database, said processor is operative to generate on the display a paging display comprising the sendername, subject and content. A computing device according to claim 7, wherein, if said processor determines a match between the sendername and a name in the database, said processor is operative to generate on the display the corresponding telephone number and the telephone button. A process for providing a user interface on a computing device comprising a processor (200), display (210), input device and paging device for receiving pages, in response to receiving pages, the process comprising the steps of: receiving a numeric message; comparing (412) the numeric message to the telephone numbers in a database comprising at least one name and at least one telephone number; if there is a match (414) between the numeric message and a telephone number in the database, generating (416, 418) on the display a paging display comprising the name corresponding to the matched telephone number, the telephone number and a telephone button; and dialing the number displayed in response to the user selecting the telephone button using the input device; wherein the user is automatically provided with the name of the person who sent the page and a telephone button to easily call back the party who sent the page; and if there is no match between the numeric message and a telephone number in the database, generating on the display a paging display comprising the numeric message. A process according to claim 9, wherein said numeric message comprises a portion of a telephone number and said step of comparing comprises comparing the portion of the telephone number to the telephone numbers in the database, such that a match can be determined between the portion of the telephone number and the elephone number in the database and the matched telephone number is displayed. A process according to claim 9, wherein, if there is no match between the numeric message and a telephone number in the database and the numeric message comprises a number of digits corresponding to a valid telephone number, said process comprises the step of generating on the display a paging display comprising the numeric message and the telephone button. A process according to claim 9, comprising the steps of: receiving an alphanumeric message; comparing the alphanumeric message to the names in the database; if there is a match between the alphanumeric message and a ame in the database, generating on the display a paging display comprising the matched name; and if there is no match between the alphanumeric message and a name in the database, generating on the display a paging display comprising the alphanumeric message. A process according to claim 12, wherein said alphanumeric message H comprises a portion of a name, and said step of comparing comprises comparing the portion of the name to the names in the database, such that a match can be determined between the portion of the name and the name in the database and the matched name is displayed. A process according to claim 12, wherein, if there is a match between the alphanumeric message and the name in the database, said process comprises the step of generating on the display the paging display of a corresponding telephone number and the telephone button to enable the user to dial the telephone number corresponding to the name.

Inventors: ADAMS WILLIAM, FUJII TOSHIYA, GRUZEN ALEXANDER, LIBES MICHAEL, LYNCH KEVIN, MUGURA KAZUTO, ONOSAKA KAZUNOBU, TSUK ROBERT, ADAMS, WILLIAM, FUJII, TOSHIYA, GRUZEN, ALEXANDER, LIBES, MICHAEL, LYNCH, KEVIN, MUGURA, KAZUTO, ONOSAKA, KAZUNOBU, TSUK, ROBERT
Applicants: GEN MAGIC INC, SONY CORP, SONY ELECTRONICS INC, GENERAL MAGIC, INC., SONY CORPORATION, SONY ELECTRONICS INC.
Application year: 1995
Main classification: G08B5
IPC codes: H04M1, G06F13, H04Q7, H04M11, G08B5