Note: Descriptions are shown in the official language in which they were submitted.
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TELECOMMUNICATION SYSTEM
Backcround of the Invention
This invention relates generally to telecommunication
systems and more particularly to telecommunication systems
adapted for used with Internet, Intranet, Extranet TCP/IP
network protocol.
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'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.
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
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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'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'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.
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'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's digits. A processor at the central
office addresses the "features" database (and an
administration database, for billing, etc.) using the
calling party's telephone number, known as the calling
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party'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
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.
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.
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
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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.
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.
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
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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.
IO
Brief Description of the Drawinas
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:
FIG. 1 is a block diagram of a telecommunication
system according to the invention:
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:
FIG. 3 is a block diagram of a telecommunication
system according to the invention wherein a cable-based IP
network is provided;
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'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:
FIG. 5 is a block diagram of a telecommunication
system according to an alternative embodiment of the
invention; and
FIG. 6 is a flow diagram showing steps used by the
telecommunication system of FIG. 5.
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Descrit~tion of the Preferred Embodiments
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'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'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's E.164 directory telephone
number. The output of the gateway 32 is connected to the
PSTN 12.
The PSTN I2 includes a plurality of connected central
offices (C.O.s) 16a, 16b, ... 16n. Each one of the central
offices 16a-16n is similar, an exemplary one thereof, here
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central office 16a being shown in detail. Thus, central
office 16a 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 16a). The PTSN subscribers 18 include
business and residential subscribers to the PSTN 12. Thus,
for example, if one of the residential subscriber l8 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 16a through POTS, PBX, or
ISDN service, for example. The central offices 16a-16n 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 16b, are connected
directly to central office 16a by a trunk and other, more
remote central offices, such as central office 16n, are
connected indirectly to central office 18a 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 16a-16n 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.
Referring to exemplary central office 16a, such office
16a 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 16b-16n, 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.
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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 16a
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.
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'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.
The processor 22 includes a subscriber port ID unit 40
for identifying the calling subscriber'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's or a called party'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 16a
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 16n, 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
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16a through the IP network 14 (i.e, through the IP network
interface 27).
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.
Referring now to FIG. 2, two scenarios are depicted:
the one on the left is when a calling party is accessing
the central office 16a 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 16a 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 16a through the PSTN 12, the
calling party goes "off-hook" (Step 202). The central
office 16a returns "dial-tone" and identifies subscriber'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's E. 164 and provides processor 22 with
calling features subscribed to by the calling party (Step
208). The central office 16a 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'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'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 16a converts central office protocol into
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TCP/IP network protocol for switching network 22 and routes
call to called party via the IP network 14 using called
party'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's E. 164 (Step 214).
Considering now the case where the central office 16a
has been accessed through the IP network 14. Here, the
l0 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's PC
(Step 220). The client software includes: the central
office's IP network TCP/IP address; the subscriber's E.164:
and the subscriber'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'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 16a 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 16a
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's
E. 164 and provides processor 22 with calling features
subscribed to by the calling party (Step 208). The central
office 16a 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'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's IP network flag.
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(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 16a 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'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
l0 network 28 routes call to called party through PSTN 12
using called party's E. 164 (Step 214).
It is noted that the central office 16a, 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.
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 16a'-16n'. The cable modems 400
are coupled to Subscriber personal computers (PCs) 402 and
telephones 404, as indicated. The cable-based central
offices 16a'-16n' are similar to the central offices 16a-
16n described in connection with FIG. 1 and like elements
are designated with the same numerical designation. Thus,
the central offices 16a'-16n' are connected to the PSTN 12
by the trunk units 23, as indicated. The central offices
' 16a'-16n' 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'.
With the system l0', Subscribers connected to the
cable-based IP network 14' by the modems 400 are able to
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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'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.
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 16a"
16n" 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 16a'-16n' on the IP
network 14, Steps 202-206 and Steps 212 and 214 (FIG. 1)
are not used.
Here, each central office 16a" - 16n" 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.
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 16a". The system 10" processes signals
received by the central office 16a", for example, from the
members of the common group through the IP network 14 and
makes such calling features available to the members.
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Other embodiments are within the spirit and scope of
the appended claims.
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