Abstract:
A telecommunication system for enabling a subscriber to calling features available by a central office to have access to such calling features when such subscriber is accessing the central office through either a line connected to the central office or an Internet, Intranet, Extranet (i.e., IP) network which uses the TCP/IP network protocol. The method includes the steps of: processing signals received by the central office from the subscriber through either the IP network or the line connected to the central office to determine whether the subscriber is placing a call to the central office through either the line to the central or through the IP network; and making such calling features available to the subscriber independent of whether the subscriber is connected to the central office through the line to the central office or through the IP network. With such a system, calling feature provided at a central office are available to a subscriber to such calling features anywhere ion the world via the IP network.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates generally to telecommunication systems and more particularly to telecommunication systems adapted for used with Internet, Intranet, Extranet TCP/IP network protocol.  
         [0002]     As is known in the art, Internet, Intranet, Extranet networks (referred to herein as IP networks) have supplemented public service telephone networks (PSTNs) in providing telephony services. For example, client software is available for enabling an Internet subscriber to place calls to a called party through the Internet. Typically, the calling party accesses the Internet via an Internet Service Provider (ISP) through either a modem or a local area network (LAN) router. Data is transmitted from the calling party&#39;s ISP through the Internet using an Internet protocol, typically the Transmission Control Protocol (TCP) and the Internet Protocol (IP) commonly referred to collectively as TCP/IP. This TCP/IP protocol is also used for Intranets/Extranets serving a specific closed group of subscribers/users. Thus, the term IP network will be used to include any network using the TCP/IP network protocol. The routing of information through an IP network is based on TCP/IP addressing. A TCP/IP address is 32 bits long and is commonly expressed as four decimal numbers ranging from 0 to 256, with each number separated by a dot.  
         [0003]     As is also known in the art, when accessing the ISP with a modem, the ISP makes available a modem in a modem pool in what is sometimes referred to as a “point-to-point” protocol. When accessing the ISP with a direct leased line, as from a LAN or cable company (CATV), data packets transfer between the LAN or cable and the IP network directly as IP packets of information. The routing through the IP network is, as noted above, using the TCP/IP network protocol with each point on the IP network having a TCP/IP address. A router server is coupled to the IP network to convert between an E.164 telephone number (i.e., using a central office addressing protocol) and TCP/IP address (i.e., the IP TCP/IP network addressing protocol). Thus, for example, if a cable-based IP user wishes to call a called party on the PSTN network, the calling party dials the called party&#39;s E.164 directory number, the router server converts the dialed number to an TCP/IP number, the call is routed through the cable-based IP network to the TCP/IP address of an ISP gateway which then converts the TCP/IP address to the called party&#39;s E.164 directory telephone number and directs the call through the central office on one of the lines (i.e., a trunk line) into the central office.  
         [0004]     As is also known in the art, a variety of services, or features, are available to subscribers of the PSTNs. For residential PSTN subscribers, these features include: Plain Old Telephone Service (POTS); custom calling features (such as, call waiting, call forwarding, three-way calling, and speed calling, for example); advanced calling features (such as, called ID); Advanced Services for Display-Based Telephone Sets (ADSI); Digital Voice and Data on One Line (ISDN); Voice-Activated Services; Operator Services; and Voice Mail. For business PSTN subscribers, these feature include: ISDN Line-Level Interface (BRI); ISDN High-Bandwidth Trunk Interface (PRI); Centrex Business Telephone Groups; Automatic Call Distribution (ACD); Frame Relay Data Transmission; Videoconferencing; and Dialable Wideband Services/Bandwidth on Demand. A list of the features subscribed to are stored in a “features” database at the central office connected to the PSTN subscriber (i.e., the subscriber&#39;s central office, end office, or local switch). Thus, when a calling party goes “off-hook”, the central office returns a dial-tone and then the calling party enters a called party&#39;s digits. A processor at the central office addresses the “features” database (and an administration database, for billing, etc.) using the calling party&#39;s telephone number, known as the calling party&#39;s E.164. The central office processor reads the called digits and provides switching signals to a central office switching network to route the call to the called party with the calling party having available the subscribed features stored in the “features” database. It is noted that the central office communicates internally and with other central offices in the PSTN with protocols (i.e., protocols adapted for use with analog (POTS), ISDN, and PBX, for example) which are different from the TCP/IP network protocol.  
       SUMMARY OF THE INVENTION  
       [0005]     In accordance with the present invention, a method is provided for enabling a subscriber to calling features available by a central office to have access to such calling features when such subscriber is accessing the central office through either a line connected to the central office or an IP network. The method includes the steps of: processing signals received by the central office from the subscriber through either the IP network or the line connected to the central office to determine whether the subscriber is placing a call to the central office through either the line to the central or through the IP network; and making such calling features available to the subscriber independent of whether the subscriber is connected to the central office through the line to the central office or through the IP network.  
         [0006]     With such an arrangement, calling feature provided at a central office are available to a subscriber to such calling features anywhere in the world via an IP network.  
         [0007]     In accordance with another feature of the invention, the central office includes a database for storing a relationship between each one of the subscribers served by the central office and calling features subscribed to such one of the served subscribers. A processor in the central office detects when a calling one of the subscribers served by the central office is accessing the central office from either the subscriber line unit or an IP network interface. The processor addresses the database using the central office protocol and provides the calling subscriber with the subscribed calling features when routed to a called party.  
         [0008]     In accordance with still another feature of the invention, the central office includes an IP network interface for converting between a central office protocol and an IP protocol. A processor at the central office is coupled to the IP network through the IP network interface. A switching network in the central office has ports fed by a subscriber line unit, trunk units, and the IP network interface. The switching network routes calls between the ports selectively in accordance with switching signals provided by the processor using the central office protocol with the calling party having available calling features subscribed to by the calling subscriber.  
         [0009]     In accordance with another feature of the invention, a telecommunication system adapted for use with an IP network is provided. The system includes a public service telephone network comprising a plurality of connected central offices each one being connected to a plurality of subscribers serviced by the central office. At least one of the central offices comprises a processor coupled to: a subscribe line unit servicing the subscribers served by the central office; trunk units coupled to other ones of the central offices; and an IP network interface. The IP network interface converts between a central office protocol and an IP protocol. The processor is coupled to the IP network through the IP network interface. A switching network is provided having ports fed by the subscriber line unit, the trunk units, and the IP network interface. The switching network routes calls between the ports selectively in accordance with switching signals provided by the processor using the central office protocol. A database is provided for storing a relationship between each one of the subscribers served by the central office and features subscribed to by such one of the served subscribers. The processor detects when a calling one of the subscribers served by the central office is accessing the central office from either the subscriber line unit or the IP network interface and addresses the database with the central office protocol to provide such calling subscriber with calling subscribed features when the calling subscriber is routed to a called party through the switching network. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     For a better understanding of the invention, reference is made to the following description of an exemplary embodiment thereof, and to the accompanying drawings, wherein:  
         [0011]      FIG. 1  is a block diagram of a telecommunication system according to the invention;  
         [0012]      FIG. 2  is a flow diagram showing steps used by the telecommunication system of  FIG. 1  in enabling a subscriber to calling features available by a central office of the system to have access to such calling features when such subscriber is accessing the central office through either a line connected to the central office or an IP network;  
         [0013]      FIG. 3  is a block diagram of a telecommunication system according to the invention wherein a cable-based IP network is provided;  
         [0014]      FIG. 4  is a flow diagram showing steps used by the telecommunication system of  FIG. 3  in enabling a subscriber to calling features available by a cable company&#39;s central office of the system to have access to such calling features when such subscriber is accessing the central office through a cable based IP network;  
         [0015]      FIG. 5  is a block diagram of a telecommunication system according to an alternative embodiment of the invention; and  
         [0016]      FIG. 6  is a flow diagram showing steps used by the telecommunication system of  FIG. 5 .  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]     Referring now to  FIG. 1 , a telecommunication system  10  is shown to include a public service telephone network (PSTN)  12  and an IP network  14 . The services of the IP network  14  are provided by IP network Service Providers (ISPs)  13 . These ISPs  13  are accessed by personal computer (PC) connected modems, not shown, at PSTN subscriber&#39;s business, home, hotel room, airport, for example, or by dedicated leased lines from LANs  19 . It should also be noted that the ISPs  13  are also connected to cable companies (CATV)  21  to enable direct, non-modem, connections into the IP network  14  from a PC or digital telephone. Each of the ISPs  13  has a unique TCP/IP address to enable their interconnection through the IP network  14 . When accessing the ISP  13  with a modem, the ISP  13  makes available a modem in a modem pool using a “point-to-point” protocol. When accessing the ISP  13  with a direct leased line, as from a LAN  19  or cable company (CATV)  21 , data packets transfer between the LAN  19 , or cable company  21 , and the IP network  14  directly as IP packets of information. In each case, the routing through the IP network  14  is with the TCP/IP network protocol with each point on the IP network  14  having a TCP/IP address. It is noted that a router server  30  is coupled to the IP network  14  to convert between an E.164 telephone number and TCP/IP address. Thus, for example, if a cable user wishes to call a called party on the cable system, the calling party dials the called party&#39;s E.164 directory number, the router server  30  converts the dialled number to an TCP/IP number, the call is routed through the IP network  14  to the TCP/IP address of a gateway  32 , which then converts the TCP/IP address to the called party&#39;s E.164 directory telephone number. The output of the gateway  32  is connected to the PSTN  12 .  
         [0018]     The PSTN  12  includes a plurality of connected central offices (C.O.s)  16   a ,  16   b , . . .  16   n . Each one of the central offices  16   a - 16   n  is similar, an exemplary one thereof, here central office  16   a  being shown in detail. Thus, central office  16   a  is connected to a plurality of the PSTN subscribers  18  through subscriber/central office telephone lines  20  (i.e. a twisted-pair typically within two miles of the central office  16   a ). The PTSN subscribers  18  include business and residential subscribers to the PSTN  12 . Thus, for example, if one of the residential subscriber  18  may have in addition to a telephone, a personnel computer (PC) connected to the subscribers telephone line  20  through a modem, not shown. A business subscriber  18  may be connected to the central office  16   a  through POTS, PBX, or ISDN service, for example. The central offices  16   a - 16   n  are shown interconnected by trunks lines (i.e., units)  23 . One of the trunk lines  23  is connected to a gateway  32 . Some of the central offices, such as office  16   b , are connected directly to central office  16   a  by a trunk and other, more remote central offices, such as central office  16   n , are connected indirectly to central office  18   a  through tandem switches  25 , as shown. It should be understood that the PSTN  12  is here a worldwide network and interconnections among the central offices  16   a - 16   n  include satellite links or optical fiber cable (SONET), for example. Further, the interconnection may be through virtual circuits, as when links in the network  12  use packet switches, such as ATM switches.  
         [0019]     Referring to exemplary central office  16   a , such office  16   a  includes: a processor  22  coupled to a plurality of subscribers  18  through a concentrator  27  and a subscribe line unit  24 ; trunk units  23  coupled to other ones of the central offices  16   b - 16   n , as shown; an IP network interface  27  for converting between a central office protocol and an TCP/IP network protocol; a switching network  28 ; an administration database  30 ; and a features database  32 , as shown. The processor  22  is coupled to the IP network  14  through a trunk unit  29  and the IP network interface  27 , as shown.  
         [0020]     The switching network  28  has ports fed by the subscriber line unit  24 , the trunk units  23 , the trunk unit  29 , and the IP network interface  27 . The switching network  28  routes calls between the ports of the switching network  28  selectively in accordance with switching signals provided by the processor  22  in accordance with the central office protocol. The administrative database  30  is addressable by a calling party E.164 address and stores billing information and other statistical information. The features database  32  stores a relationship between each one of the PTSN subscribers  18  served by the central office  16   a  and features subscribed to by such one of the served PTSN subscribers  18 . These features, herein collectively referred to as calling features, include, for example: call waiting, call forwarding, three-way calling, speed calling, caller ID, voice mail, and Centrex Business Telephone Groups.  
         [0021]     As noted in  FIG. 1 , the features database is addressed using the central office protocol which uses an E.164 number to identify the calling party&#39;s telephone number. Thus, for example, the PTSN subscriber  18  calling from telephone number NXX-XXX1 has, in this example, subscribed to call waiting, 3-way calling, call forwarding, call hold and is a member of a centrex group.  
         [0022]     The processor  22  includes a subscriber port ID unit  40  for identifying the calling subscriber&#39;s directory number (i.e., an E.164 number protocol). The processor  22  also includes a trunk ID unit  42  fed by the trunk units  23  for identifying a calling party&#39;s or a called party&#39;s E.164 directory number. The processor  22  is also fed the E.164 number produced by the IP network interface  27  when a call is received by a subscriber to the central office  16   a  through the IP network  14 . This may be where the PTSN subscriber  18  is on a trip and logged into an ISP  13  serving central office  16   n , for example. The processor  22  includes an IP network “Flag”  31  which is set when the calling PTSN subscriber  18  is accessing the central office  16   a  through the IP network  14  (i.e, through the IP network interface  27 ).  
         [0023]     The processor  22  detects when a calling one of the subscribers  18  served by the central office  12  is accessing the central office  12  from either the subscriber line unit  40  or the IP network interface  27 . The processor  22  addresses the features database  32  and the administrative database  30  using the central office protocol (e.g. analog, ISDN, or PBX) to provide such calling PTSN subscriber  18  with his/her subscribed calling features.  
         [0024]     Referring now to  FIG. 2 , two scenarios are depicted: the one on the left is when a calling party is accessing the central office  16   a  through the IP network via the IP network interface  27 ; and the one on the left depicts the scenario when a calling party is accessing the central office  16   a  through the subscriber line unit  24  or the trunk lines  23  (i.e., through the PSTN  12 ). Thus, when a call is placed to the central office  16   a  through the PSTN  12 , the calling party goes “off-hook” (Step  202 ). The central office  16   a  returns “dial-tone” and identifies subscriber&#39;s E.164 via subscriber port ID unit  40  (Step  204 ). The calling party enters the called party digits (Step  206 ). The central office processor  22  addresses “features” and “administration” databases  30 ,  32 , respectively, with calling subscriber&#39;s E. 164 and provides processor  22  with calling features subscribed to by the calling party (Step  208 ). The central office  16   a  reads the called party digits to generate routing control signals for central office switching network  28  (Step  210 ). The processor  22  addresses the “features” and “administration” databases  30 , 32  with the called party&#39;s E. 164 and provides the processor  22  with the features subscribed to by the called party (Step  211 ). The processor  22  checks the called party&#39;s IP network flag. (i.e., Has the IP network “flag”  31  been set ?) (Step  211 ). If the called party has logged onto the IP network, the IP network interface  27  at the central office  16   a  converts central office protocol into TCP/IP network protocol for switching network  22  and routes call to called party via the IP network  14  using called party&#39;s TCP/IP IP network address protocol (Step  216 ). If, on the other hand, the called party has not logged onto the ip network (i.e. the IP network “flag”  31  has not been set), the switching network  28  routes call to called party through PSTN  12  using called party&#39;s E. 164 (Step  214 ).  
         [0025]     Considering now the case where the central office  16   a  has been accessed through the IP network  14 . Here, the calling party logs onto the IP network  14  using the local IP network Service Provider (ISP)  13  (Step  218 ). The client software is called up in the calling party&#39;s PC (Step  220 ). The client software includes: the central office&#39;s IP network TCP/IP address; the subscriber&#39;s E. 164; and the subscriber&#39;s personal identification number (PIN) (Step  220 ). The calling party enters called party digits on his/her PC (Step  222 ). The client software sends, via the PC, the subscriber&#39;s E. 164 to central office via the ISP  13  using central office TCP/IP IP network protocol (Step  224 ). The IP network interface  27  at the called central office  16   a  converts the TCP/IP IP network protocol into central office protocol and sets “IP network flag”  31  to indicate to calling party has logged onto IP network  14  (Step  226 ). At this point, the central office  16   a  processes calls placed to it from the PSTN  12  or the IP network  14  in the same manner. Thus, the central office processor  22  addresses “features” and “administration” databases  30 ,  32 , respectively, with calling subscriber&#39;s E. 164 and provides processor  22  with calling features subscribed to by the calling party (Step  208 ). The central office  16   a  reads the called party digits to generate routing control signals for central office switching network  28 . The processor  22  addresses the “features” and “administration” databases  30 , 32  with the called party&#39;s E. 164 and provides the processor  22  with the features subscribed to by the called party (Step  211 ). The processor  22  checks the called party&#39;s IP network flag. (i.e., Has the IP network “flag”  31  been set ?) (Step  212 ). If the called party has logged onto the IP network, the IP network interface  27  at the central office  16   a  converts central office protocol into TCP/IP IP network protocol for switching network  22  and routes call to called party via the IP network  14  using called party&#39;s TCP/IP IP network address protocol (Step  216 ). If, on the other hand, the called party has not logged onto the IP network (i.e. the IP network “flag”  31  has not been set), the switching network  28  routes call to called party through PSTN  12  using called party&#39;s E. 164 (Step  214 ).  
         [0026]     It is noted that the central office  16   a , with its switching network  28 , processor  22  and databases  30 ,  32  are, because of the IP network interface  27 , available as an accessible adjunct to the all users of the IP network  14 . Thus, a central office with the IP network interface can be configured as a worldwide Centrex, a cable-based IP provider can access the central office and route telephone calls or other data to subscribers of the PSTN or to others connected to the cable-based IP network.  
         [0027]     More particularly, referring to  FIG. 3 a  telecommunication system  10 ′ is shown where a cable-based IP network  14 ′ is coupled to cable modems  400  and cable company central offices  16   a ′- 16   n ′. The cable modems  400  are coupled to Subscriber personal computers (PCs)  402  and telephones  404 , as indicated. The cable-based central offices  16   a ′- 16   n ′ are similar to the central offices  16   a - 16   n  described in connection with  FIG. 1  and like elements are designated with the same numerical designation. Thus, the central offices  16   a ′- 16   n ′ are connected to the PSTN  12  by the trunk units  23 , as indicated. The central offices  16   a ′- 16   n ′ each includes a call processor  22 ′, trunk ID  40 , administration database  30 , features database  32 , IP network  27  interface coupled to the cable-based IP network  14 , trunk unit  25  and switching network  28 ′.  
         [0028]     With the system  10 ′, Subscribers connected to the cable-based IP network  14 ′ by the modems  400  are able to subscribe to the same telephone features available to subscribers of the central offices  16  ( FIG. 1 ). Thus, referring to  FIG. 4 , a flow diagram shows the steps used by the telecommunication system of  FIG. 3  in enabling a subscriber to calling features available by a cable company&#39;s central office of the system to have access to such calling features when such subscriber is accessing the central office through a cable based IP network. It is noted that the method does not use Steps  202 ,  204 , or  206  described above in connection with  FIG. 2 , and here the “Internet Flag”  31  is always in a “set” condition.  
         [0029]     Referring now to  FIG. 5 , a telecommunication system  10 ″ is shown. Here, the IP network  14  is connected to the PSTN  12  through gateways  32 , subscriber PCs through ISPs  13 , and a router  30 , as shown. Each central office  16   a ″- 16   n ″ includes a processor  22 ′ like that described in connection with  FIG. 3 .  FIG. 6  is a flow diagram showing steps used by the telecommunication system of  FIG. 5 . Here, again, as with the system  10 ′ described in connection with  FIGS. 3 and 4 , the “Internet Flag”  31  is always in a “set” condition. Here, because all calls originate and terminate for the central offices  16   a ′- 16   n ′ on the IP network  14 , Steps  202 - 206  and Steps  212  and  214  ( FIG. 1 ) are not used.  
         [0030]     Here, each central office  16   a ″- 16   n ″ may be a owned by a global network carrier and used to deliver ubiquitous telephony feature services to worldwide subscribers of the IP network  14 , for example, to all subscribers within a worldwide corporation.  
         [0031]     Thus, the system  10 ″ enabling members of a common group (i.e., a company) to have access to a common set of calling features in the features database available from the central office  16   a ″. The system  10 ″ processes signals received by the central office  16   a ″, for example, from the members of the common group through the IP network  14  and makes such calling features available to the members.  
         [0032]     Other embodiments are within the spirit and scope of the appended claims.