Abstract:
In a telephone conferencing system, a digital communication network such as the Internet is used to establish and control the telephone connections between multiple conferees with the telephone network being the means of exchanging verbal information. Each conferee may have a computer connected to the digital network, and each has an independent telephone instrument connected to the public switched telephone network. An in-charge conferee utilizes his computer containing appropriate software to initiate the conference and to control the participation of the conferees. The in-charge conferee sends digital control signals to a switch interface controlling a telephone switch as a gateway to the telephone network using SS7 control signals. These SS7 control signals include the commands by which the conferee telephones are rung up, brought on line, or dropped from the conference. The switch provides telephone status information back over the digital network, and the in-charge conferee, as well as other conferees provided with appropriate software, display this status information on their PC monitors.

Description:
This application is a continuation of application Ser. No. 10/705,571, filed Nov. 10, 2003, and now U.S. Pat. No. 7,522,542, which is hereby incorporated by reference herein in its entirety and was a continuation of application Ser. No. 10/087,671, filed Mar. 1, 2002, and now U.S. Pat. No. 6,661,779, which was a continuation of application Ser. No. 09/819,079, filed Apr. 30, 2001, and now U.S. Pat. No. 6,480,474, which was a continuation of application Ser. No. 09/587,080, filed Jun. 3, 2000, and now U.S. Pat. No. 6,266,328, which was a continuation-in-part of application Ser. No. 09/212,786, filed Dec. 16, 1998, and now U.S. Pat. No. 6,072,780, which was a continuation-in-part of application Ser. No. 08/918,564, filed Aug. 22, 1997, now abandoned which claimed the benefit of priority pursuant to 35 U.S.C. §119 of Provisional Application 60/024,592, filed Aug. 26, 1996. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to telephone conferencing, and in particular to dial up telephone conferencing utilizing computer control. 
     2. Description Relative to Prior Art 
     In the art, it is known that telephone conferences may be implemented through “conferencing centers” provided as a service by local and long distance telephone companies. A list of telephone numbers of the conferees and the date and time at which the conference is to begin is supplied to a conference center operator who performs the dialing operations to bring the conferees simultaneously on line to initiate the conference. This technique is limited by the necessity of setting up a relatively inflexible forum in which all participants must be designated in advance, and the inclusion and reliance upon outside telephone company personnel to implement the conference. 
     A more recent form of conferencing utilizes digital networks such as the Internet that are publicly accessible by individual computers (typically PCs) via Internet Relay Chat (IRC) hosts. The conferees come on line and are interconnected by means of the host, and may utilize software which allows fully duplexed communication between the PCs. Typically, the conference is conducted with the exchanged information visually appearing on the individual PC display screens. In more sophisticated applications allowing audio communication between the conferees, additional hardware is required at each PC site. A microphone and analog to digital converter provide digitized audio input to a PC by means of appropriate software, such as commercially available VocalTec software, and the audio output is derived from the digital information transmitted over the Internet by use of a digital to analog converter feeding a speaker. Encryption software may be employed to “scramble” the digital information transmitted via the network, but all potential conferees must be provided with this software, and must be alerted to the fact that it is being used. Hence, a conference of multiple conferees requires additional hardware and software at each PC site in order to implement a conference by means of the Internet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with respect to the drawings, which: 
         FIG. 1  is a block diagram of the system of the invention, 
         FIG. 2  is a drawing of a computer display according to the invention, 
         FIG. 3  is a drawing of a second embodiment of a computer display according to the invention, and 
         FIG. 4  is a block diagram of the invention showing the information of  FIG. 1  in greater detail. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , a conferee station  10  consists of a PC computer  18  and a telephone  20 . Conferee stations  12 ,  14 , correspondingly have PC computers  22 ,  26  and telephones  24 ,  28 . Other conferee stations, i.e.  16  may still be connected into the conference network without the requirement of a computer; the conferee station  16  comprising only the telephone  17 . All the PCs are connected to the Internet network  30  using standard Transmission Control Protocol/Internet Protocol (TCP/IP) connect software. The telephones  20 ,  24 ,  28 ,  17  are tied into the telephone network  32  in a conventional manner. It will be noted that the telephones  20 ,  24 ,  28 ,  17  are independent of the Internet network  30 . A switch interface  33  controlling a telephone switch  34  is also connected so as to receive control signals via the Internet  30  and to transmit them to the telephone network  32 , as will be described below. 
     Any one of the conferee stations  10 ,  12 ,  14 , possessing a PC, may be designated as Conference Meister. For convenience of explanation, it is assumed that conferee station  14  is designated as Conference Meister. To implement this designation, PC  26  of conferee station  14  is provided with additional software which allows PC  26  to communicate with the switch interface  33  both to control the telephone switch  34  and to receive status information from the telephone switch  34 , via the Internet  30 . 
     The Conference Meister station  14  and the switch interface  33  communicate over the TCP/IP transport layer of the Internet  30  using the Internet&#39;s User Datagram Protocol (UDP) with checksum. A common fixed-length interprocess message called the Conference Protocol Data Unit (CDPU), using the software format further described below in Table I, is exchanged between the Conference Meister  14  and the switch interface  33 , in the data field of a UDP-Datagram. The switch interface  33  converts the CDPU into Signalling System 7 (SS7) commands which act on the switch  34 , and attendantly, on the telephone network  32  to control the conferees telephones  20 ,  24 ,  28 ,  17 . SS7 is an internationally recognized telephony standard of 255 commands for controlling telephone calls via switch  34  using standard lookup table procedures. The switch interface  33  interacting with the switch  34  may be implemented incorporating a standard micro-computer such as a Motorola 68705P5 performing the table lookup translation of SS7 commands into CPDU commands stored in its ROM memory. It will be noted that the switch interface  33  is bidirectional, and telephone connection status information as established by the switch  34 , i.e. ringing, off-hook, on-hook busy, for all participants is transmitted back via the Internet to the Conference Meister for icon display on his PC. 
     All fields in the CPDU are ASCII character fields. The CPDU consists of 32 bytes of data as follows: 
     
       
         
               
               
               
               
             
           
               
                   
               
               
                 Session ID/ 
                 Conference ID/ 
                 Command/Response Code/ 
                 Data/ 
               
               
                   
               
             
             
               
                 4 bytes 
                 2 bytes 
                 2 bytes 
                 24 bytes 
               
               
                   
               
             
          
         
       
     
     The Session ID and Conference ID fields contain administrative “housekeeping” information. The Command/Response Code field indicates the message type and the message meaning. Parameters of the Data Field are fixed length subfields and depend upon the message type. Detailed descriptions of the Command/Response Code field are shown below in Table I. 
     
       
         
               
               
               
               
             
           
               
                 TABLE I 
               
               
                   
               
               
                 Code 
                 Command 
                 Response 
                 Meaning 
               
               
                   
               
             
             
               
                 HE 
                 ✓ 
                   
                 HELLO, Conference Meister&#39;s Request for Session- 
               
               
                   
                   
                   
                 Id. 
               
               
                 LO 
                   
                 ✓ 
                 LOGON. The Switch Interface&#39;s response to a 
               
               
                   
                   
                   
                 Conference Meister&#39;s HE (Hello) assigning him his 
               
               
                   
                   
                   
                 temporary Session-Id, and signaling him to logon. 
               
               
                 LO 
                 ✓ 
                   
                 LOGON. A Conference Meister&#39;s logon. 
               
               
                   
                   
                   
                 information giving used id, password, and account 
               
               
                   
                   
                   
                 number in the data field. 
               
               
                 RS 
                   
                 ✓ 
                 RESOURCES. The Switch Interface&#39;s acceptance of 
               
               
                   
                   
                   
                 a Conference Meister&#39;s LO (Logon) 
               
               
                 EC 
                 ✓ 
                   
                 ESTABLISH CONNECTION. A Conference 
               
               
                   
                   
                   
                 Meister&#39;s request that a specified telephone number 
               
               
                   
                   
                   
                 be connected to a conference. 
               
               
                 SU 
                   
                 ✓ 
                 SUCCESS. The Switch Interface&#39;s response to an EC 
               
               
                   
                   
                   
                 (Establish Connection) request. If successfully 
               
               
                   
                   
                   
                 completed. It returns a connection-id used to refer to 
               
               
                   
                   
                   
                 this members conference connection. 
               
               
                 FA 
                   
                 ✓ 
                 FAIL. The reply sent when LO (Logon) or EC 
               
               
                   
                   
                   
                 (Establish Connection) fails. Failure details are 
               
               
                   
                   
                   
                 carried in the data field. 
               
               
                 DC 
                 ✓ 
                   
                 DISCONNECT. A request from the Conference 
               
               
                   
                   
                   
                 Meister to disconnect a conference members 
               
               
                   
                   
                   
                 connection, or to terminate a conference. (disconnect 
               
               
                   
                   
                   
                 all member connections on the conference). 
               
               
                 DC 
                   
                 ✓ 
                 DISCONNECT. An unsolicited response from the 
               
               
                   
                   
                   
                 Switch Interface notifying the Conference Meister 
               
               
                   
                   
                   
                 that a conference members connection has been 
               
               
                   
                   
                   
                 disconnected. 
               
               
                 ST 
                 ✓ 
                   
                 STATUS. This command is the Conference Meister&#39;s 
               
               
                   
                   
                   
                 means of maintaining and reconstructing its 
               
               
                   
                   
                   
                 conference information in the face of dropped 
               
               
                   
                   
                   
                 connections and unreliable datagram transmissions. 
               
               
                 ST 
                   
                 ✓ 
                 STATUS. The Switch Interface&#39;s reply to a 
               
               
                   
                   
                   
                 Conference Meister&#39;s status request. 
               
               
                 ER 
                   
                 ✓ 
                 ERROR. This is the reply used to signal invalid 
               
               
                   
                   
                   
                 message parameters, such as Session-Id. 
               
               
                 IH 
                 ✓ 
                 ✓ 
                 I&#39;M HERE. This message confirms that Conference 
               
               
                   
                   
                   
                 Meister and Switch Interface are still in contact 
               
               
                   
                   
                   
                 during intervals when there is no command/response 
               
               
                   
                   
                   
                 traffic between them. 
               
               
                   
               
             
          
         
       
     
     In the above description of the invention, the Conference Meister  14  initiates the conference. By providing CDPU software to the other conferees, the invention allows any other one of the conferee stations, i.e.  10 ,  12 , to serve as a Conference Meister. 
     The functional interrelation of the elements of the system illustrated in  FIG. 1  may be further understood by reference to  FIG. 4 . In  FIG. 4 , the abbreviations, used industry-wide, have the following meanings: SSP=Central Office (i.e. Service Signalling Point), SCP=Service Control Point, (it is an alternate SS7 entry point), and STP=Signal Transfer Point. (In the drawings, different but related elements are identified with the same reference characters, albeit that corresponding elements in the various drawings are distinguished by primes.) The components of the telephone system are expanded in the box  14 ′ showing one or more interconnected telephone central offices, e.g.  100 ,  104  that also contain control elements of the SS7 system, e.g.  110 ,  112 . As one example of the interaction between the telephone system and the control disclosed in the present invention, a call placed by telephone  17 ′ using conventional dialing enters the system through telephone central office  116 . The call is internally routed, if necessary, by the SS7 control system over the telephone network to a telephone central office  104  which is connected to a telephone system/Internet interface,  33 ′ and  34 ′, that sends SS7 signals to an Internet computer  118  that a telephone call is in process and destined to the Internet  30 ′. (The dashed lines of  FIG. 4  denote digital control functions; while the heavy black lines denote transmitted audio telephone signals as will be described below.) As is known in the art, within the Internet system are digital computers, e.g.  118 , acting as routers, servers and capable of performing other digital manipulations. Hence, via the interface/switch control path  33 ′,  34 ′ the telephone central office advises the Internet computer  118 , via the SS7/Internet control interface, that an audio signal is to be passed to the Internet. The telephone central office  104  transmits  120  the voice signals  122  originating at telephone  17 ′, to the Internet computer  118  where it is digitized, if necessary, and packetized for transmission on the Internet. This switching and inter-node connecting of this entire process has taken place between the telephone system  14 ′ and the Internet  30 ′ under control of SS7 signals. Internet computer  118  converts or maps the SS7 command signals to TCP control signals that route and process the packets through the Internet, as disclosed above. The message  124  transits the Internet  30 ′ to its destination, say, PC  28  of  FIG. 1  where software decodes the audio message  124 , rings the telephone  28 , and provides an analog audio signal for telephone  28 , corresponding to audio signal  122 , generated at telephone instrument  17 ′. 
     In a second embodiment of the invention, the system of  FIG. 1  may be further configured to provide an inherent call-back capability. Though it uses the same conferencing software described above, call-back can be between just two parties. Essentially each PC station is set up so it can serve as a “conference meister”; no other special software or hardware need be installed on a station&#39;s PC. Only the initiating station requires a PC or other access to the Internet. A suitably programmed touchtone phone can be used to access the Internet without the use of a computer such as the PC. The two party call-back feature sets up the call via the Internet with the conversation taking place on the normal telephone system in a manner substantially the same as that described above for conferencing. 
     Referring to  FIG. 2 , a participating PC call-back station shows a display chart  40  on its monitor. The display chart  40  contains the station identification  42  (e.g. Richard) and a contact list  39 , and the PC station&#39;s call-back telephone number  44 . The contacts are shown with their complete dial-up telephone numbers, e.g.  46 ,  48 , and by clicking on one or more of the displayed contacts, calls are dialed to the selected parties via the Internet and the switch  34  of  FIG. 1 , as previously described for conference calling. It will be appreciated that single parties can be selected to allow two person telephone conversation utilizing the convenience of simplified “point and click” dialing via the stored telephone numbers shown on the PC monitor screen. In the two party call-back connection system described above, it is not necessary to have two telephone lines at a PC station, i.e. one for connection to the Internet and one for carrying the telephonic conversation. With a single telephone line, the system software may be set to instantly disconnect the Internet connection after the called party&#39;s number is transmitted by the PC to the switch  34 , and to ring the call initiator&#39;s telephone simultaneously. In this manner, the calling party and the called party are connected by means of a single telephone line in seconds. 
     Anonymity of the caller is preserved by the invention even when the calling party has automatic numbering identification (ANI) or “Caller ID”. Since the system makes all its connections to the called party via the call-back technique from the remote switch  34  under control of the “conference meister” software, the only records of all the connected telephone numbers are recorded at the switch  34 , including the number of the calling party. This occurs because the caller or “conference meister” is also one of the call-back numbers. Each connection is shown as a separate call on the inter-office telephone control (SS7) software originating from the switch  34 , not from a calling party&#39;s telephone. The switch  34  can have an anonymous telephone number assigned as the originating number. Alternately, the calling party can designate some other listed number for ANI sending or Caller ID purposes which would key the called party as to who is calling. 
     With the anonymous option, no traceable record of a call is available locally. This minimizes industrial espionage at hotels, customer offices, and even private homes where merely the fact that certain parties made a call could be valuable information. The proper legal authorities can always get the full records from the central switch  34  if need be to document who initiated the call, and which telephones were called. 
     In a third embodiment, the call-back system can be expanded to include an advertising feature. Referring to  FIG. 3 , a display  40 ′ is expanded to include an advertising block  50 . Under this embodiment, in order to place a call via the call-back system or activate a conference, the program requires clicking on the advertising block  50  by the caller to create a record that the advertisement was seen by the caller. Various subroutines can then be activated such as requiring additional periodic clicks on the advertisement to keep the call connected, or linking the caller to a web page of the advertiser providing additional information as to the users of the system. 
     It will be noted that the displays  40 ,  40 ′ are to be implemented in various colors, and that the selection by clicking on any portion of the display will be highlighted in a manner known in the computer art. 
     The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. For example, other data networks, such as a private intranet rather than the Internet, may be used for digital data communication among the conferee PCs, as well as other telephone signaling.