Abstract:
For analog telephone service subscribers, an apparatus and a method is provided for displaying a caller&#39;s originating number and/or the current time of day on the subscriber&#39;s incoming call line identification equipment. The subscriber&#39;s originating telephone number is obtained from a database within the telephone switching system providing POTS service to the subscriber. The time of day is obtained from a real-time clock within or in communication with the telephone switching system. Data is preferably transmitted to the subscriber&#39;s equipment by analog frequency shift keyed protocol.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a method and apparatus for displaying information to a telecommunications station. More particularly, this invention relates to an improvement for analog telephone station displays wherein the display includes originating number identifying information and/or the date and/or time of day information. 
   2. Description of the Related Art 
   A service which has become more and more popular in recent years is one for indicating to a called customer the identification of the caller. With conventional analog telephones, this service, called incoming calling line identification (ICLID) or Caller ID, is provided through the Public Shared Telephone Network (PSTN) by means of an auxiliary display on the called party&#39;s telephone equipment which receives information from the PSTN identifying the calling party between the first two rings and uses the received information to display the number of the calling party. A problem of the prior art is that, for analog lines, while ICLID does provide information to help the called customer on incoming calls, ICLID does not provide certain significant information from the telecommunications network to help the calling customer on outgoing calls, or while a customer is idle or talking. 
   U.S. Pat. No. 5,608,788 to Demlow et al. describes a partial solution to this problem. That patent, for an information display provided to the calling party, teaches displaying many types of information on the calling telephone, including the following: (1) the name of the called customer; (2) a motto, slogan, advertising, or cost message from the called customer; (3) information to give the calling party additional options, such as automatic callback or an invitation to leave a voice message; (4) information from the central office reporting conditions such as overload; (5) a service identification mark from the central office switching system and/or an inter-exchange carrier. Useful as this information is, there is additional information that is perhaps more useful to a calling party that is not taught by Demlow. 
   Under various circumstances, it is desirable for a calling party&#39;s telephone equipment to be provided with the originating number identifier (ONI, or simply the telephone number) of the calling telephone line. For example, a calling party may wish to determine whether a call directed to a particular terminating number (terminating number identifier or TNI) is a toll call from the calling party&#39;s telephone line. Such a determination may be made if the ONI of the call is known. In further example, for calling arrangements where toll charges are ONI-TNI dependent, a calling party will need the ONI to calculate the toll charges to a particular TNI. In yet further example, the calling party&#39;s telephone equipment may have generic Least Cost Routing (LCR) software installed, that can determine and execute the least expensive route for a particular telephone call. LCR determinations typically require the telephone equipment to possess both ONI and TNI information. In yet further example, in circumstances where the calling party wishes to direct a called party verbally to call the calling party back at the calling party&#39;s ONI, the calling party must know his ONI to be able to provide that information. In other situations, the calling party may connect his own telephone equipment to the telephone line, for example a modem operatively coupled to a computer. The calling party&#39;s equipment in such situations may need to have the ONI of the telephone line to determine which of a plurality of available service access numbers are appropriate for the ONI&#39;s calling area; for example where the equipment is a computer with modem and the service to be accessed is an Internet connection, based upon the ONI the computer may determine an appropriate local access TNI for Internet service from a database within the computer. For these and other reasons, what is needed is a way for a calling party (or the calling party&#39;s telephone equipment) to obtain the originating number identifier from the public shared telephone network. 
   Under various circumstances also, it is desirable for the calling party&#39;s telephone equipment to be provided with the current date and/or time of day by the PSTN. For example, some LCR determinations may be based upon toll structures that are time of day and/or day of week dependent. While LCR in the prior art relies on time of day and day of week data from clock/calendar functionality inherent in the LCR equipment, obtaining date and time information directly from the PSTN may provide a greater degree of accuracy in LCR determinations. In more general terms, date and time of day information provided on demand in a simple and readily accessed form from an authoritative source can be utilized to great advantage by a telephone subscriber in many ways: this information, obtained from the PSTN, may be applied, not only to equipment related to telecommunications over the telephone line, but also throughout the telephone subscriber&#39;s home or office, in programming various devices and actions that are date and/or time dependent. For these and other reasons, what is needed is for a calling party (or simply a telephone subscriber) to obtain date and/or time of day information from the PSTN. 
   SUMMARY OF THE INVENTION 
   In accordance with the principles of this invention, in a telecommunications network having a switching system for serving a calling customer, an advance is made over the prior art by providing the calling customer with specific data supplied from or via a connected central office prior to, or during, the time that the calling party is dialing and/or while the called customer is being alerted (i.e., while the called telephone is ringing), and, for appropriately equipped stations, after the call has been established. The specific data to which this invention relates is the originating telephone number and/or the current time-of-day and/or date. Depending on the circumstances, this information supplied to the calling customer may come from a database shared by a plurality of central office switching systems, from a database of the central office switching system connected to the customer, or from a switching system real-time clock. This information may be accessed using a signaling network such as the CCS7 network which is currently employed to help establish calls and for conveying the calling number to the called customer for ICLID. The information is provided in response to a signal, such as a supervisory signal or a series of signals such as those for conveying a dialed number. 
   In accordance with one specific embodiment of the invention, the device that is used to display information to the calling party is an ICLID device, heretofore used only for displaying the incoming number to called parties and such additional information as taught by Demlow to calling parties. As in Demlow, in this embodiment the calling customer receives a frequency shift keyed (FSK) signal for controlling an ICLID display device, either while the station is idle, or when off-hook but prior to receiving audible tone, or between bursts of audible tone when the called party is being alerted (the audible tone may interfere with FSK signaling), or when the telephone station is in the talking state. 
   In accordance with this embodiment, the originating number identifier and/or the date and/or time of day can be displayed on the calling telephone. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram of a telecommunication network for processing customer information in accordance with the methods of  FIGS. 2–5 ; 
       FIGS. 2–3   b  are flow diagrams of various methods of processing calls and transmitting data to the ICLID device of a calling party&#39;s off-hook station in accordance with the invention; 
       FIG. 4  is a flow diagram of a method of transmitting data in accordance with the invention to an ICLID device when a station is idle (on-hook); and 
       FIG. 5  is a state diagram of an ICLID device for practicing the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  is an architectural block diagram illustrating the operation of the invention. The switching system (switch)  101  is a 5ESS.® Switch, extensively described in AT&amp;T Technical Journal, Vol. 64, No. 6, part 2, pp. 1305–1564, July/August 1985, and manufactured by AT&amp;T, which has capabilities for switching both voice and data, as described in Beckner et al., U.S. Pat. No. 4,592,048. This switch is adapted, for example, to handle integrated services digital network (ISDN) telephone stations such as telephone station  150 , to which the present invention is not directed. The ISDN telephone station set  150 , comprises a handset  151  and display  152 . This station set is equipped with an CCITT ISDN Basic Rate Interface (BRI), as described in CCITT Red Book Fascicle III.5 Series 1 Recommendation and has the capability of handling standard Q.931 interface, as described in CCITT Red Book Fascicle VI.9 Recommendation Q.931. This switch is equipped to deal with station sets served via the basic rate interface (BRI)  162 , or as telephone station  125  shows, those station sets served via the primary rate interface (PRI)  126 . 
   Even though this description is directed in detail to a switch that may be adapted to serve ISDN stations, it will be appreciated by those of ordinary skill in the art that if only analog telephones are served by a particular switch, the invention can be practiced for those telephones equipped with ICLID devices even if the serving central office switching system cannot serve ISDN stations. 
   In any case, since the present invention is not directed to ISDN telephones but rather to analog telephones, it is more relevant to the present description that the switching system also has the capabilities for dealing with ordinary analog telephones such as telephone station  124  equipped, in this case, with an incoming calling line identification (ICLID) device  127  via an analog line  172 . Further, the switching system can support a data link like  117  to serve peripheral control devices like database control  118  with a regional database  120  and optional database real-time clock  119 . Also, switching system  101  can support data link  133  to access other switching systems via the CCS7 network  132  which interfaces switching system  141  serving station set  146  and regional database  142 . Switching systems  101  and  141  are interconnected via the public switched telephone network (PSTN)  150  which is considered to include local exchange and inter-exchange networks. 
   The switch  101  comprises a processor  110  for controlling the switch. The processor  110 , in turn, comprises a central processing unit  108 , a stored call control  106  program for controlling the operations of the central processing unit, and call data  107 . The switch also comprises a local database system  116 , storing data such as: (1) customer lines connected to the system, such as the Q.931 equipped customer line  162 , (2) interconnecting networks  132 , (3) data links, such as data link  133  connected to the system, and (4) data about the database control  118  connected to the system via data link  117 . CPU  108  controls a transaction recorder  113  such as a magnetic tape unit which records billing information associated with services offered in accordance with applicant&#39;s invention. CPU  108  accesses a real-time clock  109 , for supplying time-of-day and/or date data for various data processing functions associated with the operation of switch  101 , including billing recordation functions performed by transaction recorder  118 . CPU  108  also accesses a local database system  116  for supplying data for display at telephone stations connected to switching system  101  or for supplying data in response to requests received from CCS7 network  132  over data link  133 . The switch also comprises a voice and data switching network  112  which can be used for transmitting data among processor  110  and database control  118 , and for transmitting voice and data among data links coming into the system, such as data link  133  to CCS7 Network  132 , and customer lines such as customer line  172 . The CCS7 Network  132  which may include one or more switching systems is used for accessing the called station  146  from switch  101 . Voice and data switching network  112  is connected to control unit  110  via a control connection  111 . Voice and data switching network  112  is further connected to data base control  118  via data link  117 . 
   The change required in the switching system to implement the present invention is the addition of a program in the processor  110  of the switch for executing the tasks described in the flow charts of  FIGS. 2–5 . It is to be understood that depending on circumstances, the information being supplied to the calling customer may come from the local database  116 , or from a database shared by a plurality of central office switching systems, like the regional database system  120 , from data base real-time clock  119  or directly from system real-time clock  109 . The database control  118  and regional database  120  are used for obtaining data about the calling or called terminal and/or called station set when this data is either requested by the local database system  116  or initiated by the database control  118  itself Either data base real-time clock  119  or system real-time clock  109  is used for obtaining time-of-day and/or date data when initiated by control  118 . 
   In ISDN applications, unrelated to the present invention, a service request is generated from the ISDN station set  150  when the calling party lifts the handset  151 , which sends a Q.931 SETUP message over the BRI line  162  to the switching system  101 . In analog applications, germane to the present invention, when the calling party&#39;s telephone station  124  goes “off-hook”, the station equipment changes the impedance on analog line  172 , which is treated as a service request by the network  112 , as is well known to those of ordinary skill in the art. In any case, a service request is detected by the voice and data switching network  112  and relayed via control connection  111  to call control  106  in processor  110 . Call control  106  then sends calling party identification and line status query message  122  to the database control  118  via the data link  117 . The database control  1118  queries the regional database  120  over the data link  117 . For embodiments of this invention that provide the ONI to the calling party, the composition of data message  122  comprises information obtained from this query. In embodiments of this invention that provide the time-of-day and/or date to the calling party, the composition of data message  122  comprises such information obtained either from database real-time clock  119  or from system real-time clock  109 . Data message  122  is sent to the voice and data switching network via data link  117  for delivery to call control  106  via data link  111 . 
   In alternative embodiments, database control  118  may initiate a line status query message  122 , without having first received any service request. In addition, database control  118  may compose a data message  122  comprising date and/or time-of-day information from real time clock  109  or  119 , again without the requirement of a service request. In this manner, data message  122  comprising ONI and/or the date and/or time-of-day may be composed by database control  118  while analog station  124  is idle. 
   In some embodiments of this invention, call control  106  can send data message  122  periodically to ICLID device  127  for display while analog station  124  is idle (on-hook). In other embodiments, call control  106  can send data message  122  to ICLID device  127  for display after the completion of dialing (to avoid interferences with dialing tone signals). Such data can be returned to the ICLID device after completion of dialing and before audible ring is returned to the calling party, or between bursts of audible tone. Alternatively, this data can be sent prior to returning dial tone. In any case, because the ICLID device is connected to an analog line, requiring in-band signaling, it is desirable to avoid conflicts or interferences between the frequency shift keyed signal (1200 and 2200 Hz) and the dial tone signals, or audible tone signals. 
   Summarizing the processing of information resulting in the display sent to ICLID device  127 , data message  122  is a query message to request information from the database system  120  and/or data base real-time clock  119  or system real-time clock  109 . Query data message  122  may originate from database control  118  in response to a service request; alternatively, database control  118  may, on its own, initiate query data message  122 . This query data message may include the date and/or time-of day, the calling number, line status, and the called number, the called number being used to identify the response that should be sent back to callers of that number. Message  122  is also a response message, comprising data obtained in response to a query. Significantly for the present invention, while the prior art teaches that a query data message  122  sent within the telephone network for processing queries may include the calling number ONI, nowhere is it taught for analog telephones that response message  122  ultimately transmitted to ICLID device  127  in response to a query contains the calling number ONI or the time-of-day and/or date. 
     FIGS. 2–5  are flow diagrams of the method of certain embodiments of the present invention. These figures depict the operation of the information display service arrangement, comprising the calling party analog telephone set  124 , ICLID device  127 , the switching system  101  and the regional database control  118 . Calls that are treated in accordance with the principles of this invention are information display calls. Other calls are given treatment by “normal call processing” signifying treatment in accordance with the normal practices for calls. 
   A prior art circuit used to transmit data from a switch to the ICLID device described in C. R. Doughty, U.S. Pat. No. 4,551,581. This prior art circuit can be modified in a straightforward manner to transmit data in the absence of transmitting a ringing signal, or to transmit data between bursts of audible tone or during other caller off-hook or on-hook states or to disconnect audible tone while transmitting a data message. Data messages to be transmitted before the caller dials are transmitted before dial tone is applied. 
     FIG. 2  describes the ICLID display  127  ( FIG. 1 ) prior to dialing and starts at the point where the station set is idle (action block  202 ). When a calling party requests service (goes off-hook) a service request message arrives at the switching system which passes it on to call control for processing (action block  204 ). If the information display treatment is appropriate (test  206 ), it checks the access type (test  208 ) for proper ICLID display. If either test fails (test  206  or  208 ), the call is given normal call processing treatment (action block  210 ). If both tests pass (test  206  and  208 ) call control sends customer identification and service requirements information to data base control (action block  212 ). Data base control  118  ( FIG. 1 ) determines the appropriate information data message (in the case of this invention, ONI data and/or the date and/or time-of-day) and delivers this message to call control  106  ( FIG. 1 ) (action block  214 ). Call control transmits this message using FSK data transmission (action block  216 ), marks the call record (action block  218 ), and returns to normal call processing (action block  210 ). 
   In transmitting the message to ICLID device  127  ( FIG. 1 ), care must be taken to avoid conflicts between the frequency shift keyed signal and the dial tone signals or audible tone signals, as stated previously. The Analog Display Services Interface (ADSI) described in TA-1273 issued by Bellcore permits FSK signaling to be provided off-hook; this system mutes the station receiver while FSK carrier signals are transmitted, so that a party on the receiver does not hear a loud burst of tone when FSK data is transmitted. Such a system cannot be used for signaling while the caller is dialing, however, since at least one of the dial tone multifrequency (DTMF) signals interfere with the FSK signal. Accordingly, some embodiments of this invention transmit the message to a station after the station has gone off-hook but before transmitting the dial tone that indicates that digits may be dialed. 
   Referring to  FIG. 3   a , an idle station  302  goes off-hook  304 , generating a service request to call control for processing  306 . Steps  307  to  308  represent call control activity shown in steps  204  through  216  in  FIG. 2 . After call control transmits data using FSK data transmission  308 , dialtone is sent to the customer equipment and normal call processing is enabled under call control  310 . 
   In other embodiments, after dialing is complete, as detected by the switching system, signals may be sent to the calling station. Referring to  FIG. 3   b , an embodiment is shown that transmits the message of the present invention immediately after dialing is complete before connecting the call. A station goes off-hook generating a service request to call control for processing  312 . In response, call control returns dialtone and enables digit collection  314 . Call control collects digits as dialed  316  and performs digit analysis  318 . Determining that a complete number has been dialed  320 , call control performs a query and obtains a message  322  as in  212  and  214  ( FIG. 2 ). Call control then transmits the message as data using FSK data transmission  324 . Subsequently, call control resumes normal call processing at  326 . 
   In yet other embodiments as described earlier, FSK data according to the present invention may be transmitted after call processing is complete, wherein a device such as that described in Doughty may receive such data between “ring” or “busy” tones sent by the system to the station. 
   Any other signaling arrangement for providing data while the caller is off-hook can also be used, some of these arrangements use a lower power level to transmit digital information so that the caller&#39;s ear is not subjected to an excessively loud signal. Data over voice signaling arrangements, well known in the prior art, can provide a convenient method of signaling to an analog station at essentially any time (other than during ringing). 
     FIG. 4  describes the ICLID display  127  ( FIG. 1 ) for on-hook messages and starts with the data base control  118  ( FIG. 1 ) initiating a request to send a message by sending address information and a data message to call control (action block  402 ). The data message is generated without receipt of a request from the station. The data message may be generated as a result of changes in the date and/or time of day information from system real-time clock  109  ( FIG. 1 ) or data base real-time clock  119  ( FIG. 1 ). Alternatively, the data message may be generated periodically or simply from time to time, according to programming within switching system  101 , by various means well known to those of ordinary skill in the art. The terms “off-hook” and “on-hook” as used herein refer generically to the active or inactive supervisory states of any telecommunications terminal. In the present invention, messages comprise ONI and/or date and/or time-of-day information. If several messages are queued for a caller, these can be transmitted sequentially prior to providing dial tone. Call control receives the data message and address information and starts message delivery (action block  404 ). If no address information errors are detected by call control (test  406 ), call control transmits the data using FSK data transmission (action block  414 ) and marks the call record (action block  416 ), and ends the session (action block  412 ). If call address errors are detected by call processing (test  406 ), call control sends this information to data base control (action block  408 ). Data base control then updates the regional data base system and terminates the session (action block  410 ). 
     FIG. 5  is a prior art state diagram of an ICLID device  127  as taught by Demlow. A prior art circuit is described in C. R. Doughty, U.S. Pat. No. 4,582,956. The prior art circuit is controlled according to the first four states of the state diagram of  FIG. 5 . Initially, the connected telephone station is on-hook and the circuit is idle (state 0), and, when ringing is detected it goes into state 1. When subsequent silence is detected, the circuit goes into state 2. From state 2, if a frequency shift key (FSK) carrier signal is detected, the ICLID circuit goes into state 3 and when in state 3, FSK signals are detected and passed to a display control system. If carrier is no longer detected, the ICLID circuit reverts to state 2. If in any one of the states 1, 2, or 3, a transition from on-hook to off-hook is detected, the ICLID circuit goes back to the idle state 0. 
   In order to accomplish the objectives of this invention, three more states (states 4–6) are added to the ICLID control as set forth in Demlow. When the ICLID circuit is in the idle state (state 0) and a transition from on-hook to off-hook is detected, the ICLID circuit goes into new state 4. While in state 4, if a FSK carrier is detected, the ICLID circuit goes into new state 5, and, in new state 5, detects FSK messages which are then transmitted to the display control. While in state 5, the calling station earphone is disabled so that the caller cannot hear the FSK signals. If absence of carrier is detected the ICLID circuit goes back into state 4. While in either state 4 or state 5, if the telephone instrument goes from off-hook to on-hook, the ICLID circuit goes back to the idle state 0. In addition, if while in state 5 or state 4, an answer signal is recognized, the ICLID circuit goes back to the idle state 0. (At this time, the message can be retained until the subscriber goes on-hook; while in state 0, a transition from off-hook to on-hook is ignored in this embodiment). The answer signal is recognized at switching system  101  in order to allow charging for the call to begin. The answer signal to the ICLID device while in state 5 can be a specific brief FSK message from either switch  101  or terminating switching system  141 . The transition from state 4 to state 0 may also be accomplished by a simple timeout. In addition, if FSK carrier is detected while on-hook or off-hook (in state 0, idle) the ICLID circuit goes to state 6, in which it can receive data messages. If the FSK carrier disappears, the ICLID circuit goes back to idle (state 0). 
   The “display” discussed herein may be visual static (characters or graphical), visual dynamic, audible, or tactile (for use by disabled users), and may be in one or more media (e.g., audible and visual). Accordingly, instead of delivering the information for visual display, the process could alternatively relay the information as a voice message, as a video message, as data or as any other kind of out-of-band signal message. 
   The display itself can be controlled by a processor with memory in the terminal, which can then display a stored or generated result, selected and possibly modified by the received data. Further, the display device may be simply a receiving device operatively connected to equipment at the station for further processing and/or display of the message data sent according to the present invention. 
   Although the invention has been described with a certain degree of particularity, it should be recognized that elements thereof may be altered by persons skilled in the art without departing from the spirit and scope of the invention. Accordingly, the present invention is not intended to be limited to the specific forms set forth herein, but on the contrary, it is intended to cover such alternatives, modifications and equivalents as can be reasonably included within the scope of the invention. The invention is limited only by the following claims and their equivalents.