U.S. patent application number 09/836000 was filed with the patent office on 2002-03-14 for wide area communication networking.
This patent application is currently assigned to Ameritech Corporation. Invention is credited to Bossemeyer, Robert Wesley JR., Goering, Scott Christopher, Gorman, Michael George, Halling, Dale Brian, Kagan, Denise Violetta, Neumann, Jeffrey, Pickard, Michael Steven, Stuckman, Bruce Edward, Tisiker, Michael.
Application Number | 20020031143 09/836000 |
Document ID | / |
Family ID | 23144243 |
Filed Date | 2002-03-14 |
United States Patent
Application |
20020031143 |
Kind Code |
A1 |
Bossemeyer, Robert Wesley JR. ;
et al. |
March 14, 2002 |
Wide area communication networking
Abstract
A wide area communications network (500) includes a first
digital subscriber line (502). A first network interface device
(504) connects to the digital subscriber line (502). The first
network interface device (504) separates an ISDN channel (508) from
a digital subscriber channel (510). An ISDN telephone (508) is
connected to the network interface device (504). A protocol
translator (512) is connected to the network interface device (504)
by the digital subscriber channel (510). A hub (514) is connected
to the protocol translator (512). A plurality of devices (516, 518)
is connected to the hub (514). A digital subscriber line access
multiplexer (506) is connected to the first digital subscriber line
(502). The digital subscriber line access multiplexer (506)
separates the digital subscriber channel from the ISDN channel
(522). A public switched telephone network (523) is connected to
the ISDN channel (522). An asynchronous transfer mode network (526)
is connected to the DSLAM (506) by a first virtual circuit (524) of
the digital subscriber channel. An ISP (528) is connected to the
DSLAM (506) by a second virtual circuit (530) of the digital
subscriber channel. A LAN 532 is connected to the ATM network (526)
by the first virtual circuit (524).
Inventors: |
Bossemeyer, Robert Wesley JR.;
(St. Charles, IL) ; Halling, Dale Brian; (Colorado
Springs, CO) ; Goering, Scott Christopher;
(Naperville, IL) ; Gorman, Michael George;
(Schaumburg, IL) ; Kagan, Denise Violetta;
(Riverwoods, IL) ; Neumann, Jeffrey; (Hoffman
Estates, IL) ; Pickard, Michael Steven; (Highland
Park, IL) ; Tisiker, Michael; (Westland, MI) ;
Stuckman, Bruce Edward; (Algonquin, IL) |
Correspondence
Address: |
BRINKS HOFER GILSON & LIONE
P.O. BOX 10395
CHICAGO
IL
60610
US
|
Assignee: |
Ameritech Corporation
|
Family ID: |
23144243 |
Appl. No.: |
09/836000 |
Filed: |
April 16, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09836000 |
Apr 16, 2001 |
|
|
|
09296954 |
Apr 22, 1999 |
|
|
|
Current U.S.
Class: |
370/466 ;
370/419 |
Current CPC
Class: |
H04L 69/08 20130101;
H04Q 2213/13209 20130101; H04Q 2213/13399 20130101; H04M 7/1215
20130101; H04L 9/40 20220501; H04Q 2213/13299 20130101; H04Q
2213/13384 20130101; H04Q 2213/13039 20130101; H04L 12/2856
20130101; H04L 12/66 20130101; H04Q 2213/13202 20130101; H04M
7/0069 20130101; H04Q 2213/1334 20130101; H04Q 2213/13096 20130101;
H04L 12/2889 20130101; H04Q 2213/13076 20130101; H04Q 11/0428
20130101; H04Q 2213/13034 20130101; H04L 12/5692 20130101; H04Q
2213/13298 20130101; H04Q 2213/1332 20130101; H04Q 2213/13175
20130101; H04Q 2213/13296 20130101; H04L 12/4608 20130101; H04M
11/062 20130101; H04Q 2213/13003 20130101; H04Q 2213/13204
20130101; H04Q 2213/13389 20130101; H04Q 11/04 20130101; H04Q
2213/1329 20130101; H04Q 2213/13196 20130101; H04Q 2213/13099
20130101; H04Q 2213/13093 20130101; H04L 12/2883 20130101 |
Class at
Publication: |
370/466 ;
370/419 |
International
Class: |
H04L 012/56 |
Claims
What is claimed is:
1. A wide area communications network, comprising: a first digital
subscriber line; a first network interface device connected to the
digital subscriber line, the first network interface device
separating an ISDN channel from a digital subscriber channel; an
ISDN telephone connected to the network interface device; a
protocol translator connected to the network interface device by
the digital subscriber channel; a hub connected to the protocol
translator; a plurality of devices connected to the hub; a digital
subscriber line access multiplexer connected to the first digital
subscriber line, the digital subscriber line access multiplexer
separating the digital subscriber channel from the ISDN channel; a
public switched telephone network connected to the ISDN channel; an
asynchronous transfer mode network connect to the digital
subscriber line access multiplexer by a first virtual circuit of
the digital subscriber channel; an ISP connected to the digital
subscriber line access multiplexer by a second virtual circuit of
the digital subscriber channel; and a local area network connected
to the asynchronous transfer mode network by the first virtual
circuit.
2. The system of claim 1, wherein the plurality of devices include
a computer.
3. The system of claim 1, wherein the plurality of devices include
a subscriber unit and a telephone connected to the subscriber
unit.
4. The system of claim 3, further including a facsimile machine
connected to the subscriber unit.
5. The system of claim 1, further including a digital facsimile
machine connected to the hub.
6. The system of claim 1, further including a second digital
subscriber line connecting the local area network to the
asynchronous transfer mode network.
7. The system of claim 6, wherein the local area network includes
an ATM switch.
8. The system of claim 7, further including a plurality of
computers connected to the ATM switch.
9. The system of claim 8, further including a second subscriber
unit connected to the local area network.
10. The system of claim 9, further including a POTS telephone
connected to the subscriber unit.
11. The system of claim 10, further including a facsimile machine
coupled to the ATM switch.
12. A wide area communications network, comprising: a first
subscriber location; a first network interface device attached to
the first subscriber location; a first digital subscriber line
connected to the first network interface device; a first digital
subscriber line access multiplexer connected to the first digital
subscriber line; an ATM network connected to the digital subscriber
line access multiplexer; a second digital subscriber line access
multiplexer connected to the ATM network; a second digital
subscriber line connected to the second digital subscriber line
access multiplexer; a second subscriber location connected to the
second digital subscriber line; and a public switched telephone
network connecting the first digital subscriber line access
multiplexer to the second digital subscriber line access
multiplexer.
13. The system of claim 12, further including a first ISP connected
to the ATM network and a second ISP connected to the ATM
network.
14. The system of claim 12, wherein the first subscriber location
includes a first local area network.
15. The system of claim 14, wherein the first subscriber location
includes a first telephone system.
16. The system of claim 15, wherein the first network interface
device is connected to the first local area network, the first
telephone system and the first digital subscriber line.
17. The system of claim 16, wherein the first local area network
includes a subscriber unit and a telephone attached to the
subscriber unit, the subscriber unit converting an analog telephone
signal into a digital telephone signal.
18. The system of claim 17, wherein the digital telephone signal is
carried by a telephone virtual circuit.
19. The system of claim 18, wherein the telephone virtual circuit
terminates at the first ISP.
20. The system of claim 18, wherein the telephone virtual circuit
terminates at an interworking unit.
21. The system of claim 17, wherein the first local area network
includes a facsimile machine.
22. The system of claim 21, wherein the facsimile machine connects
to the subscriber unit.
23. The system of claim 21, wherein the facsimile machine is
capable of receiving and sending a digitized facsimile
transmission.
24. The system of claim 23, wherein the digitized facsimile
transmission is carried by a facsimile virtual circuit.
25. The system of claim 21, wherein the telephone system receives a
POTS signal from the first network interface device.
26. The system of claim 21, wherein the telephone system receives
an ISDN signal from the first network interface device.
27. The system of claim 26, wherein the telephone system includes
an ISDN compatible facsimile machine.
28. A wide area communications network, comprising: a first
subscriber location having a first local area network and a first
telephone system, the first local area network and the first
telephone system connected to a first network interface device; a
first DSL line connected to the first network interface device; a
first DSLAM connected to the first DSL line, the first DSLAM
separating a first DSL channel from a first telephony channel; a
public switched telephone network connected to the first telephony
channel; an ATM network connected to the first DSL channel; a
second DSLAM connected to the ATM network by a second DSL channel
and connected to the public switched telephone network by a second
telephony channel; a second DSL line connected to the second DSLAM;
and a second subscriber location having a second network interface
device connected to the second DSL line and connected to a second
local area network and a second telephone system.
29. The system of claim 28, wherein a first virtual circuit is
coupled between a first computer connected to the first local area
network and a second computer connected to the second local area
network.
30. The system of claim 29, wherein the first virtual circuit is
carried by the first DSL line, the ATM network and the second DSL
line.
31. The system of claim 28, wherein a first switched circuit
connects a first telephone in the first telephony system to a
second telephone of the second telephony system.
32. The system of claim 31, wherein the first switch circuit
connects across the first DSL line, the public switched telephone
network and the second DSL line.
33. The system of claim 28, wherein a network telephone is
connected to the first local area network by a subscriber unit.
34. The system of claim 33, wherein a first hybrid circuit connects
the first network telephone to the second telephone of the second
telephony system.
35. The system of claim 34, wherein the first hybrid circuit
comprises: a second virtual circuit connecting the first local area
network to the first DSLAM and then to an interworking unit, a
second switched circuit connecting the interworking unit to the
second DSL line through the public switched telephone network; the
second telephony channel of the second DSL line connecting to the
second telephone.
36. The system of claim 34, wherein the first hybrid circuit
comprises: a second virtual circuit connecting the first local area
network to the first DSLAM and then through the ATM network to an
ISP; an internet telephony circuit connecting the ISP through the
internet to an internet POP; a second switched circuit connecting
the internet POP to the second DSL; the second telephony channel of
the second DSL line connecting to the second telephone.
37. The system of claim 28, wherein a digital facsimile machine is
connected to the first local area network.
38. The system of claim 37, wherein a second hybrid circuit
connects the digital facsimile machine to a facsimile machine
connected to the second telephony system.
39. The system of claim 38, wherein the second hybrid circuit
comprises: a third virtual circuit connecting the first local area
network to the first DSLAM and then to an interworking unit, a
third switched circuit connecting the interworking unit to the
second DSL line through the public switched telephone network; the
second telephony channel of the second DSL line connecting to the
facsimile machine.
40. The system of claim 28, wherein the first subscriber location
is in a first local access and transport area.
41. The system of claim 40, wherein the second subscriber location
is in a second local access and transport area.
Description
CROSS REFRENCE TO RELATED APPLICATIONS
[0001] The present invention is related to the following co-pending
patent applications that are assigned to the same assignee as the
present invention, the subject matter of which are incorporated
herein by reference thereto:
[0002] 1. "Method and Apparatus for Providing a Derived Digital
Telephone Voice Channel," Ser. No. 08/742,164, filed on Nov. 1,
1996.
[0003] 2. "Home Gateway System Telephony Functions and Method,"
Ser. No. 09/061,833, Filed on Apr. 16, 1998.
[0004] 3. "Telecommunication System, Method and Subscriber Unit for
Use Therein," Ser. No. 09/119,094, filed on Jul. 20, 1998.
[0005] 4. A00472
[0006] 5. A00473
TECHNICAL FIELD
[0007] The present invention relates to telecommunication systems,
and more particularly to a wide area communication network.
BACKGROUND OF THE INVENTION
[0008] Present digital subscriber line (DSL) services are connected
from a subscriber location to an internet service provider (ISP).
DSL or ADSL (Asymmetric Digital Subscriber Line) provides a large
bandwidth pipe that is ideal for communication networking. However,
DSL uses the ATM (asynchronous transfer mode) protocol to transport
the data over a twisted pair of copper wires. Typically, DSL is run
over the local loop portion of the telephone network. ATM is a
connection oriented service and most DSL lines are set up as a
single permanent virtual circuit to an ISP. This single permanent
virtual circuit does not allow other communication applications to
use the DSL line. For instance, a user may want to share computer
data over the DSL line without running over the internet. In
addition, a user may want to use the DSL line for voice or
facsimile data. None of these applications are allowed with present
DSL services.
[0009] Thus there exists a need for a wide area communication
network that can run over DSL lines.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention is pointed out with particularity in the
appended claims. However, other features of the invention will
become apparent and the invention will be best understood by
referring to the following detailed description in conjunction with
the accompanying drawings in which:
[0011] FIG. 1 shows a schematic diagram of a telephone network in
accordance with the present invention.
[0012] FIG. 2 shows a block diagram of the telco central office 20
of FIG. 1 in accordance with the present invention.
[0013] FIG. 3 shows a schematic diagram of a telephone subscriber
location 10 such as a typical home or small office in accordance
with the present invention.
[0014] FIG. 4 shows a block diagram of a tandem location in
accordance with the present invention.
[0015] FIG. 5 presents a block diagram representation of an example
interworking unit in accordance with the present invention.
[0016] FIG. 6 presents a block diagram of a subscriber unit in
accordance with the present invention.
[0017] FIG. 7 presents a block diagram representation of a user
interface unit in accordance the present invention.
[0018] FIG. 8 presents a perspective view of a subscriber unit in
accordance with the present invention.
[0019] FIG. 9 presents a perspective view of a subscriber interface
unit in accordance with the present invention.
[0020] FIG. 10 presents a block diagram representation of a
converter in accordance with the present invention.
[0021] FIG. 11 presents a block diagram representation of an
interface unit in accordance with the present invention.
[0022] FIG. 12 presents a block diagram representation of an
interface unit in accordance with the present invention.
[0023] FIG. 13 presents a flowchart representation of a method in
accordance with the present invention.
[0024] FIG. 14 presents a flowchart representation of a method in
accordance with the present invention.
[0025] FIG. 15 presents a flowchart representation of a method in
accordance with the present invention.
[0026] FIG. 16 presents a flowchart representation of a method in
accordance with the present invention.
[0027] FIG. 17 presents a flowchart representation of a method in
accordance with the present invention.
[0028] FIG. 18 presents a block diagram of a wide area
communication network in accordance with the present invention.
[0029] FIG. 19 presents a block diagram of a wide area
communication network in accordance with the present invention.
[0030] FIG. 20 presents a block diagram of a wide area
communication network in accordance with the present invention.
[0031] FIG. 21 presents a block diagram of a wide area
communication network in accordance with the present invention.
[0032] FIG. 22 presents a block diagram of a wide area
communication network in accordance with the present invention.
[0033] FIG. 23 presents a block diagram of a wide area
communication network in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] The various embodiments of the present invention yield
several advantages over the prior art. The embodiments described
herein allow a small business to setup a wide area communication
network. This allows small businesses to transmit voice, data,
facsimile, video and other data over a wide area communication
network having DSL lines. Note that FIGS. 1-17 describe a variety
of background information about digital subscriber lines and a
method of deriving a telephone line. FIGS. 18-23 show embodiments
of a wide area communication network.
[0035] FIG. 1 shows a schematic diagram of a telephone network in
accordance with the present invention. Telephone subscribers 10 are
typically serviced by analog telephone lines carried to the central
office 20 by a subscriber loop 12 including twisted pairs of copper
wires. A number of subscribers 14 may also be connected by
subscriber loops to a remote terminal 16 which combines a number of
subscribers 14 onto a digital multiplexed data line 18 for
transmission to the central office 20. For example, a 24channel
multiplexed T1 line is commonly used in North America for the data
line 18.
[0036] Typically, a number of central offices 20 are connected by
direct trunk circuits 22 or through tandem locations 30. The tandem
locations 30 provide trunk circuits 22 to connect two central
offices or other tandem locations 30. The tandem locations 30 can
thus provide connections between central offices which do not have
direct interconnecting trunks. It is to be understood that
telephone switching networks may have multiple levels of tandem
switching or other network topologies. The unique features of the
present invention will be identified with respect to the features
of the components of the network and their unique
configuration.
[0037] FIG. 2 shows a block diagram of the telco central office 20
of FIG. 1 in accordance with the present invention. The central
office 20 preferably includes a means to provide analog telephone
lines such as conventional POTS. Conventional POTS is typically
handled by the local telephone switching device 23. Local telephone
switching devices such as a Northern Telecom DMS-100 or Lucent No.
5 ESS are well known to those skilled in the art. In alternative
embodiments, an analog telephone line may also be provided by a
Centrex type service or private branch exchange (PBX). As known to
those skilled in the art, an analog telephone service may also be
provided by a digital carrier system such as a TI carrier or other
type of concentrator.
[0038] In addition to POTS service, the central office may also
include a means to provide a digital data line. For example, a
digital data line may be implemented by a digital subscriber line
access multiplexer (DSLAM) 24 to multiplex traffic from digital
subscriber loops. Digital subscriber loops or digital carrier
systems provided by remote terminal 16 and office terminal 25
provide digital data lines which enable subscribers 10 (FIG. 1) to
transmit large amounts of digital multiplexed data traffic over the
POTS twisted pair telephone line. The digital subscriber loop is
preferably an Asymmetric Digital Subscriber Line (ADSL). ADSL
typically implements a digital subscriber line with a maximum data
rate from the central office 20 to the subscriber 10 which is
higher than the maximum available data rate from the subscriber 10
to the central office 20. For example, ADSL typically provides an
asymmetric data rate of 1.5 megabits-per-second (mbs) to the
subscriber from the central office and about 400
kilobits-per-second (kbs) from the subscriber location to the
central office. Most preferably, ADSL implements an ATM data
transmission protocol between the subscriber 10 (FIG. 1) and the
central office 20. Of course, other types of data transmission
protocols may be utilized. In alternate embodiments, the digital
data line may be provided by other types of digital carrier systems
such as a SONET ((Synchronous Optical Network) based digital
systems.
[0039] As shown in FIG. 2, the subscriber loop pairs 12 carrying
both analog voice and digital data traffic from subscribers 10 to
the central office 20 are terminated at a main distribution frame
(MDF) 26. From the MDF 26, the subscriber loops 12 are connected to
a means for separating POTS voice 32 frequencies from digital data
traffic 34 such as a splitter 28, for example. Preferably, the
splitter 28 is implemented by the DSLAM 24. The internal operation
of the splitter 28 will be described later in more detail in
connection with a splitter at the subscriber 10.
[0040] The splitter 28 preferably has two outputs: one for POTS
signals and another for data traffic. From the splitter 28, the
separated POTS voice signals 32 are connected back to the MDF 26
and onto the local switching device 23 handling POTS telephone
calls. The data traffic output of the splitter 28 is directed to
the DSLAM 24 to multiplex the digital data into a format suitable
for transport on a data network 40. Preferably, the DSLAM 24
multiplexes and packages a number of lower signal rate digital data
lines to a SONET OC-3 or a DS-1 rate signal which is carried by a
fiber optic network. Depending on the data network 40, the DSLAM 24
may operate at higher bit rates such as those appropriate for SONET
OC-12. It should be understood that the data network 40 may be of
many different topologies. Preferably, the data network 40 is
connected to a tandem location 30 to allow access to other central
offices.
[0041] In the case of subscriber loops that are connected to the
central office through a digital loop carrier system (i.e., a
remote terminal 16 and an office terminal 25), the DSLAM 24 and its
splitter 28 are preferably placed at the remote terminal 16. The
data and voice signals are separated with the splitter 28, as
described above. The voice signals are carried on the digital loop
carrier system to the office terminal 25 where they are connected
through the MDF 26 to the local circuit switch 23. Preferably, the
data signals are carried on a separate optical fiber or SONET frame
in the carrier system so that they can easily be separated from the
voice signals in the office terminal 25. These signals are
transmitted from the office terminal to the data network 40.
[0042] FIG. 3 shows a schematic diagram of a telephone subscriber
location 10 such as a typical home or small office in accordance
with the present invention. A network interface device (NID) 41
connects the subscriber to the public switched telephone network
(PSTN). The subscriber loop 12 between the subscriber 10 and the
central office 20 is terminated at the NID 41. Customer premise
equipment (CPE) such as a standard telephone set 52 or other CPE
equipment such as a key system, PBX, or computer network 56 to
access the PSTN is connected at the NID 41. Voice signals from an
analog telephone line 53 and data signals from a digital data line
55 are typically carried to the subscriber 10 on the same
subscriber pair 12.
[0043] In the preferred embodiment of the invention, the NID 41
includes a means for separating voice frequency signals from data
signals. Preferably, a splitter 44 separates voice frequency
signals from the data traffic sharing the subscriber loop 12 wire
pair. For example, to separate POTS from data traffic, the splitter
44 typically includes a high-pass filter 46 and a low-pass filter
48. To separate POTS voice signals, the low-pass filter 48 blocks
high frequency signals, for example signals above 5 KHZ, passing
only lower voice frequency signals on a conventional CPE POTS loop
50. The voice signals on the CPE POTS loop 50 are connected to
standard telephone 52 such as a Bell 500 set providing conventional
POTS service. It should be noted that a conventional computer modem
54 can also utilize the conventional CPE POTS loop 50.
[0044] To recover data traffic, the high-pass filter 46 blocks low
frequency signals, for example signals below 5 KHz, leaving only
high frequency data traffic signals to be sent out on a separate
CPE data network loop 56. The CPE data network loop 56 is connected
to CPE equipped to access data traffic, for example, a network of
personal computers. In the, preferred embodiment, the CPE data
network 56 implements an asynchronous transfer mode network (ATM).
Each of the personal computers 58 is equipped with a ATM network
interface card (NIC) to allow the computer to access the CPE data
network 56. The NIC 41 preferably also includes data segmentation
and reassembly (SAR) capability to packetize data for transmission
on the data network 56. Of course, other types of computer
networks, such as an Ethernet network, may also be implemented.
[0045] Preferably, the CPE data network 56 is also equipped with
one or more digital telephones 60 capable of interfacing the data
network 56 to allow a subscriber to place a voice telephone call
over the CPE data network 56. For example, a digital telephone 60
may be implemented with one of the personal computers 58 on the
data network 56 by adding a telephone handset and an appropriate
NIC with telephony functions. The telephone handset transmits and
receives analog voice signals similar to a conventional handset.
The computer/NIC provides SAR capability for converting analog
voice to a digital packet stream for transmission over the CPE data
network 56. The data network 56 also carries the basic telephony
signaling functions. One such system capable of providing such a
digital telephone is an ATM network based telephone system from
Sphere Communications in Lake Bluff, Ill.
[0046] Using the CPE data network 56, the subscriber 10 can place a
voice call using a telephone line derived from the digital data
line. POTS service operates as a usual over the POTS wiring 50 to
provide regular telephone service such as a telephone line carrying
analog voice signals. In addition, the data network 56 with digital
telephone 60 also has the capability to place voice telephone calls
using one or more derived voice lines implemented through the data
network, as will be explained below in more detail.
[0047] FIG. 4 shows a block diagram of a tandem location in
accordance with the present invention. The Class 5 local switch 70
typically connects local subscriber loops to the telephone network,
while a separate tandem voice switch (not shown) provides
conventional circuit-switched connections for directing POTS
traffic between central offices 20 (FIG. 1) of the PSTN. Class 5
local switches such as the Lucent 5 ESS and the Nortel DMS 100, and
tandem voice switches such as the Lucent 4ESS and the Nortel DMS
250 are known to those skilled in the art. In comparison, the means
for providing data access to data networks is preferably a packet
switch handling digital data traffic. For example, a data access
tandem switch 72 provides access to data networks carrying digital
data traffic. Preferably, the data networks are equipped to accept
ATM packet-switched connections. The data access tandem switch 72
is an ATM fabric switch configured to provide virtual connections
on demand between end users and providers of data networks and
services. The data access tandem switch 72 may connect end users to
various network service providers (NSPs) such as UUNet, MCI,
Sprintnet, and AADS (Ameritch Advanced Data Services).
[0048] The tandem location 30 may also include a means to interface
the data access tandem 72 and the Class 5 switch. For example, an
interworking unit (IWU) 74 may implement an interface between the
data access tandem switch 72 and the Class 5 switch 70 of the PSTN.
The IWU 74 enables voice telephone calls carried by the data
network 40 to access the PSTN through the Class 5 switch 70. The
IWU 74 is capable of converting a voice telephone call in the data
network protocol from the data access tandem switch 72 into the
circuit-switch protocol of the Class 5 switch 70. Preferably, the
IWU 74 interfaces an ATM packet data stream to a multiplexed
circuit-switch protocol with dynamic allocation of voice channels
such as TR-303.
[0049] FIG. 5 presents a block diagram representation of an example
interworking unit in accordance with the present invention. In
particular, the IWU 74 performs the SAR 76 of voice data from an
ATM stream into a analog voice signal. The analog voice signal is
then converted 78 into the data protocol such as a TR-303 protocol.
More preferably, as seen in FIG. 4, the IWU 74 converts the
packetized ATM voice streams to a digital PCM format which is then
converted to the desired TR-303 protocol. It should be noted that
the local switch 70 may also be directly connected to a data access
tandem 72 without the IWU interface 74. Newer generation digital
switches may be capable of directly interfacing with the data
transfer protocol of the data access tandem 72. For example, new
generation circuit-switches may directly accept an ATM data stream
for switching into the PSTN without the need for an IWU.
[0050] While a TR-303 protocol is described above, other protocols
may likewise be used in accordance with the present invention. In
particular, other protocols including a PRI protocol, TR-08
protocol or a TR-57 protocol could likewise be used within the
scope of the present invention.
[0051] With the system of FIGS. 1-5, a derived voice telephone line
using the data network can be implemented and utilized in
conjunction with the methods and systems that follow.
[0052] A caller places a digital voice call similar to an ordinary
telephone call using the digital telephone 60 of FIG. 3. The SAR
and A/D function of the digital telephone 60 converts the caller's
analog voice signals to a packetized digital data stream for
transport over the subscriber data network 56. Preferably, the
packetized data stream is in an ATM format.
[0053] The subscriber data network 56 carries the derived telephone
line data stream to the high frequency portion 55 of the DSL
devoted to digital communications. Next the high frequency portion
55 of the DSL is combined with the low frequency portion 53 of the
DSL on the subscriber loop 12 where it is transported to the
central office 20. Note, the derived telephone line uses the
digital data portion 55 of the subscriber data network 56, leaving
the lower frequency portion (POTS telephone signal) available for
analog telephone voice calls.
[0054] At the central office 20 shown in FIG. 2, the splitter 28
separates the derived telephone line data stream from POTS traffic.
The derived telephone line data stream is multiplexed by the DSLAM
24 together with a number of data streams or derived telephone line
data streams from other subscribers. For example, the DSLAM 24 may
combine data streams from a number of different subscribers into a
higher rate digital signal such as a DS-3 or OC-3 signal. The
telephone line data stream is then carried by the OC-3 signal over
the data network 40 to the tandem location 30.
[0055] At the tandem location 30 shown in FIG. 4, the derived
telephone line and data sessions are switched by the data access
tandem 72. Preferably, data sessions to a NSP are directly switched
by the data access tandem 72 to the desired NSP without entering
the PSTN. For voice calls which must enter the PSTN, the data
access tandem 72 directs the derived telephone line data streams to
the IWU 74.
[0056] The IWU 74 preferably converts the derived telephone line
data stream to a voice signal in a TR-303 format which can be
switched by the Class 5 telephone switch 70. Through the Class 5
switch 70, the derived voice call enters the PSTN and is switched
as a POTS call. If needed, a separate tandem switch establishes a
circuit connection to the desired central office 20.
[0057] FIG. 6 presents a block diagram of a subscriber unit in
accordance with the present invention. In particular, a subscriber
unit 100 allows connection with a public switched telephone
network. The public switched telephone network has at least one
switch and at least one digital subscriber line 102, such as
described in FIGS. 1-5, in communication with the switch. In
accordance with the present invention, the subscriber unit 100 is
operable to send and receive voice calls over the public switched
telephone network.
[0058] While the various embodiments of the present invention have
been described in conjunction with a public switched telephone
network, these embodiments could similarly apply to voice
communications over other communication networks. In particular,
telephone calls, within the scope of the present invention, can be
transmitted using a data communications network such as the
Internet as a transport medium for a least a portion of a call. In
these embodiments of the present invention the functionality of an
analog local switch or digital switch could be performed by a
server and router corresponding to a local Internet service
provider or could include an IP (Internet Protocol) gateway in
combination with a central office switch. Further the switch of the
present invention could be a central office circuit switch or a
packet switch depending on the nature of the network.
[0059] The subscriber unit 100 includes a digital subscriber line
interface unit 104 receives the plurality of data packets from the
digital subscriber line 102 and identifies selected ones of the
plurality of received data packets corresponding to a received data
stream of a first derived digital telephone. The subscriber unit
100 is further operable to transmit, on the digital subscriber
line, a plurality of transmitted data packets corresponding to a
transmitted data stream of the first derived digital telephone
line.
[0060] In one embodiment of the present invention data packets are
formatted in accordance with the Asynchronous Transfer Mode (ATM)
protocol. Further, a hierarchical protocol structure could likewise
be used encompassing, for instance, an Ethernet protocol carried by
ATM or an internet protocol (IP) such as TCP/IP carried by ATM.
However, other packet data protocols and hierarchical structures
and combinations could likewise be implemented within the scope of
the present invention.
[0061] Packets received by the subscriber unit 100, destined for
receipt by subscriber unit 100 include an address, consistent with
the particular protocol or protocols used for formatting the data
packets, that corresponds to either the subscriber unit 100 or to a
corresponding subscriber. In accordance with an embodiment of the
present invention whereby an IP is used, data packets directed to
the subscriber unit 100 could be identified based on a particular
IP node address or URL corresponding to either the particular
subscriber unit 100 or to a particular subscriber using subscriber
unit 100. Alternatively, an ATM address could be used for the same
purpose in an ATM protocol environment.
[0062] The subscriber unit 100 further includes a coder/decoder
106. The coder/decoder 106 receives the transmitted data stream
from analog-to-digital (A/D) converter 108 and codes the
transmitted data stream into the plurality of transmitted data
packets. The coder/decoder 106 also receives the plurality of
received data packets from the digital subscriber line interface
unit 104 and decodes the plurality of received data packets into a
received data stream to be transmitted to the digital-to-analog
(D/A) converter 110 on line 122.
[0063] Analog-to-digital converter 108 converts a transmitted
analog signal from user interface unit 112 into the transmitted
data stream. Digital-to-analog converter 110 converts the received
data stream into a received analog signal for transmission to the
user interface unit 112 on line 124.
[0064] In this fashion, digital subscriber line interface unit 104,
coder/decoder 106, A/D converter 108 and D/A converter 110 operate
in concert to send and receive basic telephony signaling between
the digital subscriber line 102 and an user interface unit 112.
This user interface unit 112 provides the basic functionality of a
standard analog telephone set. In particular, the user interface
unit 112 provides an interface to a user of the subscriber unit
and, at a minimum, generates the transmitted analog signal sent to
A/D converter 108 and generates an acoustic signal based on at
least a portion of the received analog signal.
[0065] In an alternative embodiment of the present invention, a
direct data path 114 is provided for communicating with the user
interface unit 112. This data path could carry the transmitted data
stream, the received data stream or both. In embodiments of the
present invention where the user interface unit 112 includes a
processor, data path 114 is advantageous to allow direct digital
communication without need for the conversion to analog and then
back to digital data.
[0066] FIG. 7 presents a block diagram representation of an user
interface unit in accordance with the present invention. In
particular, user interface 112 of FIG. 6 is shown in more detail in
accordance with various alternative embodiments.
[0067] User interface unit 112 optionally includes a telephone
tip/ring converter 125 that converts the analog signal line 122
from the D/A converter 110 to appear as a typical tip/ring pair 127
to telephone line interface unit 120. In particular, tip/ring
converter 125 adds a voltage bias and provides any necessary
generation or conversion of signal levels from line 122 to appear
as a standard analog telephone line, even though the analog signals
such as voice and ringing signals on line 122 where transported
over a packet data line. In various embodiments of the present
invention, the functionality of D/A converter 110, A/D converter
108 and,, tip/ring converter 125 perform the functions of a line
card used in conjunction with a digital central office switch.
[0068] Optional telephone line interface unit 120 provides an
interface between processor 126 and tip/ring converter 125 by
converting basic telephony signals such as on-hook, off-hook, and
ring signals for detection by the processor or for generation by
the processor to the tip/ring pair 127. In this embodiment, keypad
134 and DTMF tone generator 128, switch hook 132, alert signal
generator 130 and telephone handset 140 are further coupled to the
tip/ring pair 127 for directly responding to, and/or for
generating, the basic telephony signals carried by tip/ring pair
127 in a manner familiar to those skilled in the art.
[0069] While the present invention is described as including a
switch hook, other similar devices could likewise be used,
including a flash key or a receive button, within the scope of the
present invention.
[0070] However, processor 126, including a plurality of interface
ports (not specifically shown) and general memory 144, is likewise
capable of responding to and/or directly generating the basic
telephony signals in a similar manner. In this fashion, dialed
numbers can be recorded and stored for redialing or speed dialing
purposes, conditions requiring distinctive ringing patterns can be
detected and distinctive rings can be generated, stored voice
signals can be generated and received voice signals can be
analyzed, and on-hook and off-hook signaling can be generated
without the use of the switch hook.
[0071] In an alternative embodiment of the present invention the
functionality supplied by tip/ring converter 125 and telephone
interface unit 120 could be supplemented or supplanted by direct
digital connection 114 to processor 126. The plurality of interface
ports (not specifically shown) of processor 126 could provide the
appropriate conversion from the analog devices such as keypad 134
and DTMF tone generator 128, switch hook 132, alert signal
generator 130 and telephone handset 140.
[0072] In various embodiments of the present invention the user
interface unit advantageously includes a display unit. In various
embodiments, this display unit is a liquid crystal display (LCD)
capable of displaying information relating to incoming and outgoing
calls in additional to command and control information for the
operation of the subscriber unit. In particular, a graphical user
interface (GUI) for operation of the telephone is implemented using
the processor 126, the display device 136 and additional keys
138.
[0073] In a further embodiment of the present invention the
additional keys are distributed adjacent to the display unit, the
plurality of keys operable by the user to activate selected ones of
a plurality of call control options displayed on the display device
adjacent thereto. In this fashion, a plurality of call control
options such as call transfer, hold, redial, conferencing,
forwarding, speed dialing, hands free, line release, line
selection, etc., can be implemented by a user by the presentation
of a menu of commands and by pressing the key adjacent to the
displayed command on the display device.
[0074] The display device 136 is further capable of displaying a
plurality of data relating to an outgoing call, for instance, by
monitoring the digits dialed by the user and by displaying
destination telephone number reflected by these digits. The
processor further is operable to time the duration of the call from
the time the telephone line is off-hook and displaying the duration
on the display device 136. Call memory 142 is available for storing
the plurality of data relating to an outgoing call for a plurality
of outgoing calls. This data can be retrieved and reviewed by the
user or can be downloaded to an external device coupled to the
subscriber unit through data interface unit 152.
[0075] Processor 126 is further capable of receiving and decoding
caller identification data relating to the identity of an incoming
caller and the display unit is capable of displaying a plurality of
data relating an incoming call. In this fashion, caller ID signals
received during the silent interval between the first and second
rings of an incoming telephone call can be decoded and displayed to
the user before the corresponding line is taken off-hook.
[0076] Similarly, for a subscriber to a caller ID/call waiting
service who is engaged in a conversation with a first caller, the
processor 126 can receive the caller ID information corresponding
to a second caller and display it to a user for determination if
the first caller should placed on hold and the second call should
be answered. Additionally, the call disposition features
corresponding a caller ID/call waiting deluxe could likewise be
implemented using the display and either the keys of keypad 134 or
the additional keys 138.
[0077] Call memory 142 is likewise available for storing a
plurality of data relating to an incoming call for a plurality of
incoming calls. The plurality of data relating the incoming call
includes caller ID information of the calling party, the duration
of the call (if the call was completed), and data indicating if the
incoming call includes a facsimile message. In this embodiment of
the present invention the stored data can be retrieved and
displayed or downloaded as discussed earlier in conjunction with
outgoing call data.
[0078] While many of the forgoing discussions have addressed the
accessing of a single line, in various embodiments of the present
invention the subscriber unit 100 is capable of monitoring and
accessing multiple telephone lines, at least one of which is a
derived digital telephone line. In these embodiments the display
device 136 is capable of showing the status a plurality of lines,
and the user is capable of accessing and placing calls on any one
of a plurality of lines.
[0079] Further, the subscriber unit 100, through the use of
processor 126 and in response to a signal generated by the user
interface unit 112 and in response to an action of the user, is
capable of initiating a connection to a remote central office on
one or more derived digital telephone lines carried by the digital
subscriber line. In this embodiment of the present invention the
processor 126, coupled to the coder/decoder 106, and All digital
subscriber line interface 104, is capable of accepting data
corresponding to a second derived digital telephone line in
addition to a first derived digital telephone line, and the
processor 126 is further capable of monitoring the status of the
second derived digital telephone line. More generally, the
subscriber unit 100, in response to a signal generated by the user
interface unit 112 in response to an action of the user, is capable
of initiating up to N additional derived digital telephone lines,
where N is greater than 2.
[0080] In an additional embodiment of the present invention the
user interface unit 112 further comprises a smart card interface
unit 146 capable of accepting and communicating with a smart card
(not specifically shown). Preferably, smart card interface unit 146
is compatible with PCMCIA standards and can accept any of a wide
variety of such smart cards. In one such embodiment, the smart card
inserted into the smart card interface unit 146 stores a plurality
of data associated with the user and wherein the processor 126 is
capable of downloading a plurality of smart card data from a smart
card so that the use of the subscriber unit 100 can be personalized
to the particular user.
[0081] In one embodiment of the present invention the plurality of
smart card data includes a protocol address such as a IP node
address or an ATM address corresponding to the user. In this
fashion, the address of the telephone could change or be overridden
by the address of the user downloaded from the smart card so that
calls directed to the user could be sent to the particular
subscriber unit 100 over a derived digital telephone line. Once the
data was downloaded from the smart card, the subscriber unit can
automatically register the presence of the subscriber at the
location of the particular subscriber unit 100 by sending a data
message to the remote central office over the digital subscriber
line. Alternatively, the registration of the presence of the user
at the particular subscriber unit 100 containing the smart card
could be optionally effectuated only upon activation of the user
either in response to a query by the subscriber unit, such as in
response to a message displayed on the display device 136 or by
action of the user in the absence of such a query.
[0082] In a further embodiment of the present invention the smart
card data contains other personal options of the user including
custom set-up and command options for the subscriber converter.
These set-up and command options could include device macros for
performing a series of commands on the subscriber unit at the touch
of a single button and could also include a user's speed dial
list.
[0083] In another embodiment of the present invention the user
interface unit 112 further includes a keyboard 150 and wherein the
subscriber unit is capable of communication with a first data
service over the digital subscriber loop. In this fashion the
subscriber unit 100 can operate as a PC or network computer to
access data services such as internet or world wide web services
from the subscriber unit 100. In one such embodiment the
communication with the first data service over the digital
subscriber loop could use data packets that do not correspond to a
derived digital telephone line. However, one or more derived
digital lines could, nevertheless, be used for this purpose. In
this embodiment the user interface unit 112 further includes a
display driver 148 for driving a remote display device. In an
applications where communicating with a first data service the
device driver 148 allows the use of a larger display than might be
integrated in the subscriber unit itself.
[0084] In a further embodiment of the present invention, the
subscriber unit 100 specifically includes the functionality of a
fax modem. In the fashion, the subscriber unit 100 is operable to
send a receive a plurality of fax messages. In this embodiment a
received fax message or fax message to be sent could be
communicated to/from the subscriber unit using the data interface
unit 152 in combination with a document scanner or a printer or
other specific device.
[0085] In an additional embodiment of the present invention, the
subscriber unit, under the control of processor 126, performs the
functionality of a answering machine where greetings are stored and
played to incoming callers, and messages from callers are stored in
a memory device such as general memory 144.
[0086] FIG. 8 presents a perspective view of a subscriber unit in
accordance with the present invention. In particular, a subscriber
unit 100 is presented that incorporates the various features and
options presented in conjunction with the descriptions of FIG. 6
and FIG. 7. Housing 160 includes an integral display device 136,
keypad 134 and telephone handset 140. Additional keys 138 (that are
not adjacent to the display device 136) and additional keys 138'
that are adjacent to the display device 136 provide access to
advanced controls and features of the subscriber unit 100. Smart
card slot 162 corresponds to smart card interface unit 146 disposed
within the housing. Display device jack 166 is coupled to display
driver 148 within the housing 160 and data interface jack 164 is
coupled to data interface unit 152 also disposed within the housing
160.
[0087] FIG. 9 presents a perspective view of a subscriber interface
unit in accordance with the present invention. In particular, FIG.
9 presents a subscriber interface unit for use in a
telecommunication system including a switch, a local loop coupling
the switch to a subscriber location. In this embodiment, a segment
of the local loop includes copper twisted pair and the asymmetrical
digital subscriber line is carried by the local loop. Further, the
asymmetrical digital subscriber line carries a plurality of derived
digital telephone lines as described in conjunction with FIGS. 1-5.
The subscriber interface unit of FIG. 9 advantageously couples the
asymmetrical digital subscriber line to an analog land-line
telephone.
[0088] Subscriber interface unit 180 includes a housing 182 having
a top surface 184 and a bottom surface 186 substantially coplanar
to the top surface. An electrical coupler 188 provides a connection
to a cable capable of carrying the asymmetrical digital subscriber
line. An RJ-11 jack 190 provides a connection to a cable of the
analog telephone (not specifically shown). A converter 200,
disposed within the housing, coupled to the electrical coupler 188
and to the RJ-11 jack 190, converts the first analog signals
generated by the analog telephone into a first plurality of data
packets for transmission to a selected one of the plurality of
derived digital telephone lines and converts a second plurality of
data packets received from the selected one of the plurality art of
derived digital telephone lines into a second analog signal for
transmission to the analog telephone.
[0089] In a particular embodiment of the present invention the
subscriber interface unit 180 includes several optional features
that correspond to features described in conjunction with the
subscriber unit 100. Components that are common with subscriber
unit 100 are assigned common reference numerals. In addition,
subscriber unit 180 includes a first indented portion 192 of top
surface 184 for accepting the analog telephone on top thereof. A
plurality of non-skid feet are coupled to the bottom surface 186 of
the housing 182.
[0090] While an RJ-11 jack 190 is shown for coupling to the analog
land-line telephone, many other electrical connections including
other plug and jack combinations are possible within the scope of
this embodiment of the present invention. In a one embodiment of
the present invention the digital subscriber line is carried by the
standard telephone wiring within a home. In this embodiment,
electrical coupler 188 is also implemented using an RJ-11 jack,
however, like the RJ-11 jack 190, other electrical connection
options are possible within the broad scope of the present
invention.
[0091] FIG. 10 presents a block diagram representation of a
converter in accordance with the present invention. In particular,
a converter 200 is presented for use with the subscriber interface
unit 180 of FIG. 9. Digital subscriber line 102 is attached to
electrical coupler 188. An analog land-line telephone is coupled to
the converter via line 204 connected to RJ-11 jack 190. Components
that are common with subscriber unit 100 are assigned common
reference numerals. Converter 200 operates in a manner similar to
subscriber unit 100, however, some of the components of subscriber
unit 100 are supplied by an analog land-line telephone that is
attached to the unit. In other words, the functionality of user
interface unit 112 is supplied by interface unit 202 in combination
with the analog land-line telephone. to For the purposes of this
disclosure the term "subscriber unit" should include the various
embodiments of subscriber unit 100 as well as the various
embodiments of subscriber interface unit 180 in combination with an
analog land-line telephone.
[0092] In accordance with the present invention a multi-line analog
telephone can be coupled to the subscriber interface unit 180. In a
manner similar to subscriber unit 100, the combination of
subscriber interface unit 180 and the multi-line analog land-line
telephone is capable of accessing and monitoring the plurality of
telephone lines and is further capable of selecting one of the
plurality of telephone lines for conducting a voice call. The
converter 200 further is capable of converting a third plurality of
data packets received from an additional one of the plurality of
derived digital telephone lines into a third analog signal for
transmission to the analog telephone.
[0093] FIG. 11 presents a block diagram representation of an
interface unit in accordance with the present invention. In
particular, user interface unit 202 is shown for use in accordance
with one embodiment of the converter 200 of FIG. 10. Lines 122 and
124 from the A/D converter 108 and D/A converter 110 are coupled to
tip/ring converter 125 as described in conjunction with several
embodiments of subscriber unit 100. The output 204 appears as a
standard tip and ring pair to the analog land-line telephone.
[0094] The user interface unit 202 of FIG. 11 presents minimal
functionality. The inclusion of additional functions for subscriber
interface unit 180 can be desirable. In particular, many of the 35
additional functions described in conjunction with subscriber unit
100 can likewise be included in subscriber interface unit 202 in
accordance with the present invention. While the subscriber
interface unit 180 of FIG. 9 does not present each of these
additional functions, these functions may, nevertheless be included
as described in conjunction with an alternative embodiment for
interface unit 202 presented in FIG. 12.
[0095] FIG. 12 presents a block diagram representation of an
interface unit in accordance with the present invention. In
particular, an alternative embodiment of interface 202 designated
by reference numeral 202' is presented. In this embodiment,
numerous features of subscriber unit 100 are included. Components
that are common with subscriber unit 100 are assigned common
reference numerals. The output 204 of tip/ring converter 125 is
coupled to the analog land-line telephone as well as to telephone
line interface unit 120. Processor 126, display device 136,
additional keys 138, call memory 142, general memory 144, smart
card interface unit 146, display driver 148, keyboard 150 and data
interface unit 152 function as previously described in conjunction
with user interface unit 112.
[0096] FIG. 13 presents a flowchart representation of a method in
accordance with the present invention. In particular, a method for
initiating a call is presented for use with various embodiments of
the subscriber unit 100 or the various embodiments of subscriber
interface unit 180 in combination with an analog land-line
telephone.
[0097] The method begins in step 300 receiving an off-hook signal,
generated by the subscriber unit in response to an action of a
user. In one embodiment of the present invention this signal would
be generated by the switch hook of a subscriber unit responding to
the handset going off-hook. In other embodiments, an off-hook
signal could be generated by the user selecting an additional key
of the subscriber unit such as a "handsfree" key used to initiate a
call using a speakerphone function of the subscriber unit or a
"send" key commonly used by cellular telephones to initiate a
call.
[0098] The method continues in step 302 by initiating a first
derived digital telephone line of the plurality of derived digital
telephone lines in response to the off-hook signal. In particular,
the off-hook signal is converted to data in a transmitted data
stream that is converted to a transmitted data packet that is
transmitted along the digital subscriber line to a switch through
an interworking unit. This begins a data packet exchange between
the switch and the subscriber unit carrying the basic telephony
signals corresponding to the derived digital telephone line. In one
embodiment of the present invention the data packet is addressed to
an interworking unit where it is converted to a signaling protocol
for interface to the switch.
[0099] FIG. 14 presents a flowchart representation of a method in
accordance with the present invention. In particular, a method for
initiating and terminating a call is presented for use with various
embodiments of the subscriber unit 100 or the various embodiments
of subscriber interface unit 180 in combination with an analog
land-line telephone.
[0100] Steps 300 and 302 proceed as described in conjunction with
the method described in connection with FIG. 12. The method
continues in step 304 by generating a line-in-use signal, at the
subscriber unit, indicating a first derived digital telephone line
is in use. In step 306, a visual indicator is generated at the
subscriber unit in response to the line-in-use signal. In a
preferred embodiment of the present invention, the visual indicator
includes a display, on display device 136, of the destination
telephone number and of the duration of the call. Optionally, the
visual display includes an indicator of an assigned number for the
derived digital line. Thus, in a multi-line environment, a visual
designator such as "line 1" can be displayed as well.
[0101] The method continues in step 308 by monitoring, at the
subscriber unit, the content of at least one of the plurality of
data packets of the digital subscriber line. In a preferred
embodiment of the present invention, each of the incoming packets
is continuously monitored by the subscriber unit to determine if
any of the plurality of incoming data packets has an address
corresponding to the subscriber unit. If so, the data payload from
each such packet is transformed to the received data stream for
transfer to the user interface unit to conduct the call. Further
the transmitted data stream would be converted into a plurality of
data packets addressed to the switch.
[0102] In step 310, an on-hook signal is received, generated by the
subscriber unit in response to an action of a user. In one
embodiment of the present invention this signal would be generated
by the switch hook of a subscriber unit responding to the handset
being placed on-hook. In other embodiments, an on-hook signal could
be generated by the user selecting an additional key of the
subscriber unit such as a "line release" key used to terminate a
call using a speakerphone function of the subscriber unit.
[0103] In step 312 the derived digital telephone line is terminated
in response to the on-hook signal. In particular, the call is
terminated when the on-hook signal is transmitted to the switch and
the subscriber unit stops creating a transmitted data stream and
transmitted data packets. The exchange of data packets between the
switch and the subscriber unit corresponding to the derived digital
telephone line ends. In step 314, the visual display indicating the
line is use is also terminated with the termination of the
call.
[0104] FIG. 15 presents a flowchart representation of a method in
accordance with the present invention. In particular, a method for
responding to an incoming call is presented for use with various
embodiments of the subscriber unit 100 or the various embodiments
of subscriber interface unit 180 in combination with an analog
land-line telephone. One of ordinary skill in the art will
recognize, based on the disclosure herein, -that this method may be
used in conjunction with the other methods of the present invention
described herein.
[0105] The method begins is step 320 by monitoring the content of
at least one data packet to detect an incoming call. As previously
discussed, in a preferred embodiment of the present invention the
step of monitoring is performed continuously. Prior to the
initiation of an outgoing call or the receipt of an incoming call,
the step of monitoring is important to both the detection of usage
of other derived digital lines and the detection of an incoming
call for the particular subscriber unit. During a call the step of
monitoring is important to identifying data packets that correspond
to the call in progress.
[0106] The method continues in step 322 by determining if a
received packet indicates an incoming call. After receiving a data
packet addressed to the particular subscriber unit, the data
portion of the packet is translated to a received data stream-the
data indicating a ring signal from the central office. In response,
the method initiates ringing as shown in step 324. In step 326,
caller ID information, that is, in a preferred embodiment,
transmitted between the silent interval between the first and
second ringing signals, is decoded, displayed on the display
device, and is stored in a call memory.
[0107] The method proceeds in step 328 to determine if an off-hook
signal is received. If an off-hook signal is received, the call is
conducted in step 330 by continuously sending and receiving data
packets corresponding to a derived digital telephone line between
the subscriber unit and the central office for the duration of the
call. In step 332, a line-in-use signal is generated in response to
the off-hook signal and in step 334 a visual indicator is generated
and displayed to the user. In a preferred embodiment of the present
invention this visual indicator includes the duration of the call
and the received caller ID data. The visual indicator may
optionally include a line designator indicating the line number of
the line in use.
[0108] In step 336 the method proceeds by determining if an on-hook
signal is generated in response to an action of the user. In step
338, in response to the detection of an on-hook signal the derived
digital line is terminated. The method continues by returning to
step 320 and continuing to monitor the content of the incoming data
packets for the initiation of an incoming call.
[0109] In a further embodiment of the present invention, when the
remote party engaged in a telephone call on a derived digital
telephone line goes on-hook, the subscriber unit generates an
on-hook signal a predetermined time later to terminate the line in
cases where the remote party has hung-up.
[0110] FIG. 16 presents a flowchart representation of a method in
accordance with the present invention. In particular, a method for
indicating the use of a derived digital telephone line by another
subscriber unit is presented for use with various embodiments of
the subscriber unit 100 or the various embodiments of subscriber
interface unit 180 in combination with an analog land-line
telephone. One of ordinary skill in the art will recognize, based
on the disclosure herein, that this method may be used in
conjunction with the other methods of the present invention
described herein.
[0111] The method begins in step 340 by monitoring, at the
subscriber unit, the content of at least one of the plurality of
data packets corresponding to the digital subscriber line. The
method continues in step 342 by determining that a first derived
digital telephone line is in use based on the content of the at
least one of the plurality of data packets.
[0112] In this embodiment of the present invention, the subscriber
unit monitors the traffic of data packets to determine the presence
of incoming and outgoing calls by other subscriber units that share
the same digital subscriber line. In one such embodiment the
addresses of the other subscriber units is recorded in the
particular subscriber unit of interest so that packets addressed to
the other subscriber units can be read. In an alternative
embodiment of the present invention all incoming data packets are
monitored for the presence of basic telephony signals to determine
if other derived digital telephone lines are in use.
[0113] In step 344 a line-in-use signal is generated, at the
subscriber unit, indicating a first derived digital telephone line
is in use. This line-in-use signal can be used in the subscriber
unit to display information on the status of one or more additional
lines that are use by other subscriber units connected to the same
digital subscriber line.
[0114] In operation, the present invention allows a plurality of
subscriber units to be advantageously connected to a single
subscriber line. The nature of the derived digital telephone line
allows additional telephone lines to be added on demand up to the
bandwidth limits of the digital subscriber loop. All of these lines
can be monitored and accessed by a single subscriber unit connected
to the digital subscriber line. The subscriber unit of the present
invention is capable of performing the advanced features of a
multi-line centrex-based system without the necessity of the
additional hardware. For instance, each subscriber unit can perform
three-way calling, call transfer, call forwarding, call holding
etc.
[0115] FIG. 17 presents a flowchart representation of a method in
accordance with the present invention. In particular, a more
detailed method for indicating the use of a derived digital
telephone line by another subscriber unit is presented for use with
various embodiments of the subscriber unit 100 or the various
embodiments of subscriber interface unit 180 in combination with an
analog land-line telephone. One of ordinary skill in the art will
recognize, based on the disclosure herein, that this method may be
used in conjunction with the other methods of the present invention
described herein.
[0116] Steps 340, 342 and 344 correspond to similar steps presented
in conjunction with FIG. 16. Step 346 proceeds by generating a
visual indicator in response to the line-in-use signal. In a
preferred embodiment of the present invention this visual indicator
includes the duration of the call, the received caller ID data. The
visual indicator further includes a line designator indicating the
line number of the line in use.
[0117] In step 348 an add-a-line signal is received, generated in
response to an action by the user. In one embodiment of the present
invention, this signal is generated by an off-hook signal where a
line is currently in use. In this fashion the subscriber unit
defaults to adding a new line rather than adding the user to a call
on an existing line when the receiver is picked-up during a period
when another derived digital telephone line is in use. In this
embodiment, an existing call would be accessed by a user by
pressing another key, such as a soft key, adjacent to the portion
of display indicating that an call is progress. In an alternative
embodiment the functions could be reversed and an offhook signal
would default to joining an existing call and an additional key
could be used to generate an add-a-line signal.
[0118] The method proceeds in step 350 by initiating a second
derived digital line by setting up two-way packet data
communication with the local central office. Optional steps 352 and
354 correspond to receiving a hold signal generated by the action
of the user, such a pressing a hold button, and placing the second
derived digital line on "hold". Optional steps 356 and 358
correspond to receiving a signal based on the action of a user
indicating one of a plurality of derived digital lines that are
currently active and accessing the corresponding one of the
plurality of derived digital lines.
[0119] In step 360 an on-hook signal is received and in step 362,
the second derived digital line is terminated in response to the
on-hook signal. These steps are similar in scope to steps described
in conjunction with the methods of FIGS. 14 and 15.
[0120] FIG. 18 presents a block diagram of a wide area
communication network 500 in accordance with the present invention.
The network 500 has a first digital subscriber line 502 connected
between a first network interface device (NID) 504 and digital
subscriber line access multiplexer (DSLAM) 506. The NID 504
separates an ISDN (Integrated Services Digital Network) channel 508
from a digital subscriber channel 510. A protocol translator 512 is
connected the a digital subscriber channel 510. The protocol
translator converts between the ATM format of the DSL channel 510
and a local area network format, such as Ethernet (CDCS--Collision
Sense Collision Detect). A hub 514 is connected to the protocol
translator and a plurality of devices 516, 518. The hub 514
connects the plurality of devices together and may act as a
repeater. An ISDN telephone 520 is connected to the ISDN channel
508.
[0121] The DSLAM 506 separates the digital subscriber channel from
the ISDN channel 522. The ISDN channel 522 is connected to the PSTN
(Public Switched Telephone Network) 523. The digital subscriber
channel includes a first virtual circuit 524 connected to an
asynchronous transfer mode network 526. An ISP (Internet Service
Provider) 528 is connected to a second virtual circuit 530 of the
digital subscriber channel. A local area network 532 is connected
by the first virtual circuit 524 to the ATM network 526.
Technically, the first virtual circuit 524 would extend from the
protocol translator 512 to the LAN 532.
[0122] DSL lines are a service that runs over ordinary twisted pair
(copper) wires. The DSL is connected between a central office of a
telephone company to a subscriber location. DSL uses the ATM
(Asynchronous Transfer Mode) protocol to transport the data over
the telephone wires. ATM is a connection oriented service. Before
any data is transmitted a virtual circuit must be defined between
the end points. In the case of prior art DSL services, a permanent
virtual circuit is defined between the subscriber and an ISP.
However, ATM specifies both permanent virtual circuits and switched
virtual circuits. A switched virtual circuit is set up at the
beginning of a session and torn down when the session is over,
similar to a telephone call. A virtual circuit is defined by a
virtual path identifier (VPI) and a virtual circuit identifier
(VCI). These identifiers are included in the header of every ATM
cell (packet). An ATM switch examines the VPI and VCI to determine
how to switch the cell. Since the virtual circuit (path) has been
defined before any data is sent, the ATM switch only need examine a
small portion of the identifiers. This allows the ATM switch to
switch the cell on the fly, as opposed to the store and forward
approach of routers. This makes ATM more secure and faster than
router systems such as the Internet. Note that the same physical
medium and the same bandwidth can and commonly are used for more
than a single virtual circuit. Thus in FIG. 18 the first virtual
circuit 524; the second virtual circuit 530 and the ISDN channel
508 are all carried over the single DSL line 502.
[0123] FIG. 19 presents a block diagram of a wide area
communication network 550 in accordance with the present invention.
The network includes a first DSL 552 connected to a first NID 554.
The NID splits the ISDN channel (POTS channel) 556 from the digital
subscriber channel 558. An ISDN telephone 560 is connected to the
ISDN channel 556. In another embodiment two ISDN telephones are
connected to the ISDN channel 556. The ISDN channel 556 is a BRI
(basic rate interface) ISDN channel and has two B-channels and one
D-channel. The two B-channels allow two simultaneous telephone
calls. The D-channel is used for control information, such as call
setup. The B-channels can also be used for carrying data.
[0124] A protocol translator 562 is connected to the first NID 554.
A hub 564 is connected to the protocol translator 562. The hub 564
connects together a local area network. The local area network can
include a variety of electronic devices. For instance, a digital
facsimile machine 566 is connected to the hub 564. A digital
facsimile machine 566 as used herein means a facsimile machine that
is capable of sending and receiving facsimile information
(digitized facsimile transmission) using a digital data standard as
opposed to a facsimile machine that transmits and receives
facsimile data (digitized facsimile transmission) over a POTS
telephone line. A computer 568 is connected to the hub 564. A
subscriber unit 570 is connected to the hub 564. A POTS telephone
572 and a POTS facsimile machine (facsimile machine) 574 are
connected to the subscriber unit 570. The subscriber unit 570
converts between the LAN format data and POTS signals.
[0125] A DSLAM 576 is connected to the DSL 552. The ISDN channel
556 connects the DSLAM 576 to the PSTN (Public Switched Telephone
Network) 578. A second virtual circuit 580 of the digital
subscriber channel is connected between an ISP 582 and the DSLAM
576. A first virtual circuit 584 of the digital subscriber channel
extends through the DSLAM 576, ATM network 586 to a second DSL 588.
The second DSL 588 connects to a second local area network 590. The
second local area network includes an ATM switch 592. A plurality
of computers 594, 596, a digital facsimile machine (network
facsimile machine) 598 and a second subscriber unit 600 are
connected to the ATM switch 592. A POTS telephone 602 is connected
to the subscriber unit 600. In one embodiment the subscriber unit
and telephone are combined to form a network telephone.
[0126] FIG. 20 presents a block diagram of a wide area
communication network 620 in accordance with the present invention.
The network 620 has a first subscriber location 622. A first
network interface device (NID) 624 is attached to the first
subscriber location 622. A first digital subscriber line 626
connects the NID 624 to a first digital subscriber line access
multiplexer (DSLAM) 628. The DSLAM 628 is coupled to an ATM network
630. A second digital subscriber line access multiplexer (DSLAM)
632 is connected to the ATM network 630. A-public switched
telephone network (PSTN) 634 connects the first DSLAM 628 to the
second DSLAM 632. A second digital subscriber line 636 connects the
second DSLAM 632 to a second subscriber location 638. In one
embodiment the second subscriber location 638 is attached to a
second NID.
[0127] FIG. 21 presents a block diagram of a wide area
communication network 650 in accordance with the present invention.
A first subscriber location 652 includes a first LAN 654 and a
first telephone system 656 connected to a NID 658. The LAN 654
includes a network facsimile machine 660 and a subscriber unit 662.
A POTS telephone 664 and POTS facsimile machine 666 are connected
to the subscriber unit 662. The subscriber unit converts between an
analog telephone signal and a digital telephone signal. An ISDN
facsimile machine 668 is connected to the telephone system 656. An
ISDN facsimile machine is a facsimile machine that is capable of
communicating facsimile information over an ISDN line.
[0128] A first DSL 670 connects the NID 658 to a first DSLAM 672.
An ATM network 674 is connected to the DSLAM 672. A second DSLAM
676 is connected to the ATM network 674. A second digital
subscriber line 678 connects a second subscriber location 680 to
the second DSLAM 676. A first ISP 682 and a second ISP 684 are
connected to the ATM network 674. The internet 686 connects the
first ISP 682 and the second ISP 684. An interworking unit (IWU)
688 is connected to the DSLAM 672. The IWU converts between a
packet data format and a circuit switch data format. A PSTN 690
connects the IWU to the DSLAM 676. In one embodiment the telephone
signal from the telephone 664 is carried by a telephone virtual
circuit. In another embodiment the telephone virtual circuit
terminates at the ISP 682. In this embodiment the telephone signal
is carried by the internet for a portion of the call. In another
embodiment, the telephone circuit terminates at the interworking
unit. The call is then routed as a standard circuit switched call.
In one embodiment a digitized facsimile transmission from (to) the
digital facsimile machine 660 is carried by a facsimile virtual
circuit. In one embodiment, the telephone system receives a POTS
signal from the NID 658. In this case the telephone or facsimile
machine connectd to the telephone system must be a POTS device.
[0129] This system allows a small business to setup a communication
network over a digital subscriber line. The communication network
includes computer data, voice signals and facsimile signals.
[0130] FIG. 22 presents a block diagram of a wide area
communication network 700 in accordance with the present invention.
A first subscriber location 702 includes a first local area network
704 and a first telephone system 706. The first LAN 704 and
telephone system 706 are connected to a first NID 708. A first DSL
line 710 is connected to the NID 708. A first DSLAM 712 is
connected to the first DSL line 710. The DSLAM 712 separates the a
first DSL channel 714 from a first telephony channel 716. A public
switched telephone network 718 is connected to the first telephony
channel 716. An ATM network 720 is connected to the first DSL
channel 714. A second DSLAM 722 is connected to the ATM network by
a second DSL channel 724. The second DSLAM 722 is connected to the
PSTN 718 by a second telephony channel 726. A second DSL line 728
is connected to the second DSLAM 722. A second NID 730 attached to
a second subscriber location 732 is connected to the second DSL
line 728. A second local area network 734 and a second telephone
system 736 are connected to the second NID 730.
[0131] FIG. 23 presents a block diagram of a wide area
communication network 750 in accordance with the present invention.
A first subscriber location 752 in a first local access and
transport area (LATA) 754 includes a first LAN 756 and a first
telephone system (TS-1) 758. Note the telephone system can consist
of a single POTS line or a single BRI ISDN line and the telephone
(or computer) equipment that can be connected to the line. The
first LAN 756 and first telephone system 758 are connected to a
first NID 760. The first LAN 756 includes a first computer 762, a
subscriber unit 764 and a network facsimile machine 766. A
telephone 768 is connected to the subscriber unit 764. A telephone
770 is part of the first telephone system 758. A first DSL line 772
connects a first DSLAM 774 to the NID 760. The DSLAM 774 is
connected to an ATM network 776 by a first DSL channel 778. A PSTN
780 is connected to the DSLAM 774 by a first telephony channel 782
and by an IWU 784. A second DSL channel 786 connects the ATM
network 776 to a second DSLAM 788. A second telephony channel 790
connects the PSTN 780 to the DSLAM 788. A second DSL line 792
connects a DSLAM 788 to a second NID 794. The NID 794 is attached
to the second subscriber location 796 in a second local access and
transport area (LATA) 798. The second subscriber location includes
a second LAN 800 and a second telephone system 802 connected to the
NID 794. A second computer 804 is connected to the LAN 800. A
second telephone 806 and a facsimile machine 808 are part of the
second telephony system 802.
[0132] A first ISP 810 is connected to the ATM network 776. The ISP
810 is connected to an internet POP (point of presence) 812 by the
internet 814. The internet POP 812 connects to the second DSL line
792 via an central office--service switching point (CO/SSP) 814. In
one embodiment a first virtual circuit couples the first computer
762 to a second computer 804. The first virtual circuit is carried
by the first DSL line 772, the ATM network 776 and the second DSL
line 792. In another embodiment, a first switched circuit connects
the first telephone 770 to a second telephone 806. The first
switched circuit connects across the first DSL line 772, the PSTN
780 and the second DSL line 792. In another embodiment, a network
telephone 768 is connected to the second telephony system 802 by a
first hybrid circuit. The first hybrid circuit includes a second
virtual circuit connecting the first LAN 756 to the IWU 784. A
second switched circuit connects the IWU 784 to the second DSL line
792 through the PSTN 780. The second telephony channel 790 connects
to the second telephone 806. In another embodiment the first hybrid
circuit includes a second virtual circuit connecting the first LAN
756 to the DSLAM 774, to the ATM network 776 and to the ISP 810. An
internet telephony circuit connects the ISP 810 through the
internet 814 to the internet POP 812. A second switched circuit
connects the internet POP 812 to the second DSL 792.
[0133] The second telephony channel connects the DSL 792 to the
second telephone 806. Note that the term "internet circuit" is used
to describe the routing of the call data through the internet. In
another embodiment a second hybrid circuit connects the digital
facsimile machine 766 to the facsimile machine 808. The second
hybrid circuit includes a third virtual circuit connecting a first
LAN 756 to the DSLAM 774 and then to the IWU 784. A third switched
circuit connects the IWU 784 to the second DSL line 792 through the
PSTN 780. The second telephony channel connects the DSL 792 to the
facsimile machine 808.
[0134] The network described above allows small business to setup
wide area communication networks that can transmit a variety of
types of data. The data types include computer data, voice signals,
facsimile signals and video signals. As will be apparent to those
skilled, in light of the foregoing description, almost any type of
data (signal) can be sent over the wide area network. The
communication network takes advantage of DSL services that provide
access to both packet (cell) switched or routed networks and
circuit switched networks. In addition, the wide area network is
easily reconfigurable as the business moves and expands.
[0135] The various methods described herein, in a preferred
embodiment, are intended for operation as software programs running
on a computer processor. One of ordinary skill in the art will
recognize that other hardware implementations such as bridges and
routers could be used. It should also be noted that the various
methods of the present invention could be stored on a tangible
storage medium such as a magnetic or optical disk, read-only memory
or random access memory and be produced as an article of
manufacture.
[0136] Thus, there has been described herein a concept, as well as
several embodiments including a preferred embodiment, of a wide
area communication network. The various embodiments of methods and
systems, by enabling a wide area communication network over digital
subscriber lines, provide a significant improvement over the prior
art. Additionally, the various embodiments of the present invention
herein-described have other features that distinguish the present
invention from the prior art.
[0137] It will be apparent to those skilled in the art that the
disclosed invention may be modified in numerous ways and may assume
many embodiments other than the preferred forms specifically set
out and described above. Accordingly, it is intended by the
appended claims to cover all modifications of the invention which
fall the true spirit and scope of the invention.
* * * * *