U.S. patent number RE34,380 [Application Number 07/639,480] was granted by the patent office on 1993-09-14 for method and apparatus for applying messages in a telecommunications network.
Invention is credited to Neil F. Sleevi.
United States Patent |
RE34,380 |
Sleevi |
September 14, 1993 |
Method and apparatus for applying messages in a telecommunications
network
Abstract
In a telecommunications network, a system for applying messages
or data to the customer lines of calling parties during the
"ringback" period of telephone call set up. The messages are
preferably applied between successive ringback tones during the
ringback period and are terminated when the called party answers
the call. Advertising messages, civic or company announcements,
political messages, informational messages (e.g. news or weather),
or other data can be transmitted on the telephone lines during what
is otherwise essentially unused times when the line is already tied
up.
Inventors: |
Sleevi; Neil F. (Weston,
MO) |
Family
ID: |
27093335 |
Appl.
No.: |
07/639,480 |
Filed: |
January 10, 1991 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
903993 |
Sep 5, 1986 |
04811382 |
Mar 7, 1989 |
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Current U.S.
Class: |
379/88.25;
379/202.01; 379/257; 379/373.02; 379/87 |
Current CPC
Class: |
H04M
3/4878 (20130101); H04M 3/42017 (20130101) |
Current International
Class: |
H04M
3/487 (20060101); H04M 003/02 (); H04M
003/42 () |
Field of
Search: |
;379/67,88,257,372,374,82,84,87,201,202 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1198843 |
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Dec 1985 |
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CA |
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3306313 |
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Aug 1984 |
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DE |
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57-87661 |
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Jun 1982 |
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JP |
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58-96447 |
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Jun 1983 |
|
JP |
|
0108855 |
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Jun 1983 |
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JP |
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2170377 |
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Jul 1986 |
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GB |
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Other References
Pp. 280-283, texbook entitled "Engineering and Operations in the
Bell System", by Bell Telephone Laboratories (1977)..
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Primary Examiner: Brown; Thomas W.
Claims
Having thus described the invention, I claim:
1. In a telecommunications system having a plurality of switching
systems interconnected by trunks, a plurality of customer stations
arranged in groups with each group being served by one of the
switching systems, a plurality of customer lines connecting each
switching system with the group of customer stations served
thereby, a switching network in each switching system for
establishing communication paths between calling customer stations
and called customer stations addressed by the calling stations and
means in each switching system for applying .Iadd.a
.Iaddend.periodic ringback .[.signals.]. .Iadd.signal .Iaddend.to
the line of each calling station served thereby when a called
station addressed by the calling station is idle, the improvement
comprising:
.Iadd.detection .Iaddend.means for detecting customer lines to
which ringback signals are being applied;
.[.communications signal applying means in each switching system
for applying preselected communication signals to selected customer
lines to which ringback signals are being applied, said
communication signal applying means in each switching system
applying said communication signals only to customer lines for the
group of customer stations served by the corresponding switching
system and said selected customer lines being selected according to
the identity of the called customer station; and.].
.Iadd.storing means for storing communication signals;
control means for associating said communication signals with
designated stations;
comparing means for comparing telephone numbers addressed by
calling stations with telephone numbers of said designated stations
and for indicating correspondence thereof;
communication signal applying means in each switching system for
applying said stored communication signals to a calling customer
line served by the corresponding switching system in response to
detection by said detection means that a ringback signal is being
applied thereto if said comparing means indicates correspondence of
identity of the station addressed by the calling station of the
detected calling customer line with one of said designated
stations; and .Iaddend.
means for terminating application of said communication signals to
each customer line when .Iadd.application of a .Iaddend.ringback
.[.signals.]. .Iadd.signal .Iaddend.thereof .[.are.]. .Iadd.is
.Iaddend.terminated.
2. The improvement of claim 1, wherein .[.the.]..Iadd.each
.Iaddend.ringback .[.signals are.]. .Iadd.signal comprises ringback
tone signal portions .Iaddend.each .[.applied for.]. .Iadd.having
.Iaddend.a preselected duration .[.and.]. with a preselected
interval between successive ringback .[.signals,.]. .Iadd.tone
signal portions, .Iaddend.and including timing means for timing the
application of the communication signals such that the latter are
applied during the intervals between successive ringback
.[.signals.]. .Iadd.tone signal portions and .Iaddend.are
discontinued for the duration of each ringback .Iadd.tone
.Iaddend.signal .Iadd.portion.Iaddend..
3. The improvement of claim 2, wherein said communication signals
comprise a plurality of .[.discreet.]. .Iadd.discrete
.Iaddend.messages each having a duration substantially equal to the
interval between successive ringback .[.signals.]. .Iadd.tone
signal portions.Iaddend..
4. In a telecommunications network of the type having a plurality
of switching systems interconnected by trunks, a plurality of
customer stations connected to each switching system by customer
lines, a switching network in each switching system for
establishing communications paths between calling customer
stations, means in each switching system for applying a ring signal
to the customer line of each called station addressed by a calling
station, means in each switching system for applying .Iadd.a
.Iaddend.periodic ringback .[.signals.]. .Iadd.signal including
ringback tone signal portions .Iaddend.to the customer line of each
calling station when a called station addressed thereby is idle,
and means in each switching system for applying a busy signal to
the customer line of each calling station when a called station
addressed thereby is not idle, the improvement comprising:
detecting means for detecting calling customer lines to which
ringback signals are being applied;
.[.communication signal applying means for applying preselected
communication signals to selected customer lines to which ringback
signals are being applied, said communication signal applying means
being connected in a manner to bypass said switching network and
said selected customer lines being selected according to the
identity of the called customer station;.].
.Iadd.storing means for storing communication signals;
control means for associating said communication signals with
designated stations;
comparing means for comparing telephone numbers addressed by
calling stations with telephone numbers of said designated
stations;
communication signal applying means for applying said stored
communication signals to a calling line in response to detection by
said detection means that a ringback signal has been applied
thereto if said comparing means indicated correspondence of
identity of the station addressed by the calling station of the
detected calling line with one of said designated stations, said
communication means being connected to bypass an associated
switching network; .Iaddend.
timing means for timing the application of said communication
signals in a manner such that the communication signals are applied
between successive ringback .[.signals.]. .Iadd.tone signal
portions .Iaddend.and discontinued during each ringback .Iadd.tone
.Iaddend.signal .Iadd.portion; .Iaddend.and
means for terminating the communication signals to each calling
customer line when the ringback .[.signals are.]. .Iadd.signal is
.Iaddend.terminated.
5. The improvement of claim 4, wherein said communication signals
comprise a plurality of .[.discreet.]. .Iadd.discrete
.Iaddend.messages each having a duration substantially equal to the
interval between successive ringback .[.signals.]. .Iadd.tone
signal portions.Iaddend..
6. A method of applying messages to customer stations in a
telecommunications network in which the customer stations are
connected by customer lines to switching systems having trunk
connections with other switching systems, a switching network in
each switching station for establishing communications paths
between calling customer stations and called customer stations, and
ringback equipment for applying ringback signals having
.Iadd.ringback tone signal portions of .Iaddend.a preselected
frequency and duration to a calling customer line addressing an
idle called customer station, said method comprising the steps
of:
.Iadd.associating messages with designated customer stations;
comparing telephone numbers addressed by calling customer stations
with telephone numbers of said designated customer stations;
.Iaddend.
detecting the application of .Iadd.a .Iaddend.ringback
.[.signals.]. .Iadd.signal .Iaddend.to a selected calling customer
line .[.selected according to the identity of the called customer
station addressed.].;
applying said messages to the selected calling customer line
between successive ringback .[.signals.]. .Iadd.tone signal
portions .Iaddend.in a manner to bypass said switching network
.Iadd.in response to said detecting step if the comparing step
indicates correspondence of identity of the customer station
addressed by the calling customer station of the selected calling
customer line with one of said designated customer
stations.Iaddend.; and
terminating said messages when the ringback .[.signals are.].
.Iadd.signal is .Iaddend.terminated.
7. In a telecommunications system having a plurality of switching
systems interconnected by trunks, a plurality of customer stations
arranged in groups each served by a different switching system with
the customer stations in each group being connected to the
corresponding switching system by customer lines, a switchhook for
each customer station for indicating whether the station is on hook
or off hook, a .[.stitching.]. .Iadd.switching .Iaddend.network in
each switching system for establishing communication paths between
calling customer stations and called customer stations addressed by
the calling stations, means in each switching system for applying a
periodic ringback .[.signals.]. .Iadd.signal .Iaddend.to the line
of each calling .[.stations.]. .Iadd.station .Iaddend.served
thereby when a called station addressed by the calling station is
on hook, and means for terminating the ringback .[.signals.].
.Iadd.signal .Iaddend.when an addressed called station goes off
hook to respond to the call, message applying apparatus
comprising:
an announcer in each switching system containing a plurality of
recorded messages;
.Iadd.control means for associating said messages with designated
stations; .Iaddend.
means in each switching system for applying said messages to
selected customer lines for calling stations served by the
corresponding switching system .[.when.]. .Iadd.in response to
detection of .Iaddend.ringback signals .[.are.]. being applied to
said selected customer lines, said selected customer lines being
selected .[.according to the identity of the called customer
station.].; .Iadd.if there is a correspondence of identity of the
stations addressed by the calling stations served by the selected
customer lines with said designated stations .Iaddend.
timing means for timing the application of said messages in a
manner to effect application of the messages between successive
ringback .Iadd.tone signal portions of said ringback
.Iaddend.signals and discontinuance of the messages during each
ringback .Iadd.tone .Iaddend.signal .Iadd.portion; .Iaddend.and
means for deactivating said announcer in each switching system to
terminate application of messages when .[.the.]. .Iadd.a
.Iaddend.called station addressed by .[.the.]. .Iadd.a
.Iaddend.calling station goes off hook to respond to .[.the.].
.Iadd.a .Iaddend.call.
8. Apparatus as set forth in claim 7, wherein:
the ringback .[.signals.]. .Iadd.tone signal portions .Iaddend.are
each applied for a preselected duration with a preselected interval
between successive ringback .[.signals.].; .Iadd.tone signal
portions .Iaddend.
each message has a duration substantially equal to the interval
between successive ringback .[.signals.].; .Iadd.tone signal
portions .Iaddend.and
said timing means is operable to time the application of said
messages in a manner to initiate each message at the end of a
ringback .Iadd.tone .Iaddend.signal .Iadd.portion.Iaddend..
9. Apparatus as set forth in claim 7, wherein said means in each
switching system for applying said messages applies the messages in
a manner to bypass the switching network in the corresponding
switching system.
10. In a telecommunications system having a plurality of switching
systems interconnected by trunks, a plurality of customer stations
arranged in groups with each group being served by one of the
switching systems, a plurality of customer lines connecting each
switching system with the group of customer stations served
thereby, a switching network in each switching system for
establishing communication paths between calling customer stations
and called customer stations addressed by the calling stations and
means in each switching system for applying .Iadd.a
.Iaddend.periodic ringback .[.signals.]. .Iadd.signal .Iaddend.to
the line of each calling station served thereby when a called
station addressed by the calling station is idle, the improvement
comprising:
means for detecting customer lines to which ringback signals are
being applied;
communication signal applying means in each switching system for
applying preselected communication signals to selected customer
lines to which ringback signals are being applied, said
communication signal applying means in each switching system
applying said communication signals only to customer lines for the
group of customer stations served by the corresponding switching
system;
means for terminating application of said communication signals to
each customer line when ringback signals thereto are terminated;
and
said communication signal applying means in each switching system
being connected to at least one of the trunks for the corresponding
switching system, whereby the communication signals are applied
only for calls between customer stations served by different
switching systems.
11. In a telecommunications network of the type having a plurality
of switching systems interconnected by trunks, a plurality of
customer stations connected to each switching system by customer
lines, a switching network in each switching system for
establishing communications paths between calling customer stations
and called customer stations addressed by the calling stations,
means in each switching system for applying .Iadd.a
.Iaddend.periodic ringback .[.signals.]. .Iadd.signal .Iaddend.to
the customer line of each calling station when a called station
addressed thereby is idle, and means in each switching system for
applying a busy signal to the customer line of each calling station
when a called station addressed thereby is not idle, the
improvement comprising:
detecting means for detecting calling customer lines to which
ringback signals are being applied;
communication signal applying means for applying preselected
communication signals to selected customer lines to which ringback
signals are being applied, said communication signal applying means
being connected in a manner to bypass .[.said.]. .Iadd.an
associated .Iaddend.switching network, each switching system having
one of said communication signal applying means and said
communication signal applying means for each switching system being
connected to at least one of the trunks for the corresponding
switching system, whereby the communication signals are applied
only for calls between customer stations served by different
switching systems;
timing means timing the application of said communication signals
in a manner such that the communication signals are applied between
successive ringback signals and discontinued during each ringback
signal; and
means for terminating the communication signals to each calling
customer line when the ringback signals are terminated.
12. A method of applying messages to customer stations in a
telecommunications network in which the customer stations are
connected by customer lines to .Iadd.a .Iaddend.switching system
having trunk connections with other switching systems, a switching
network in each switching .[.station.]. .Iadd.system .Iaddend.for
establishing communications paths between calling customer stations
and called customer stations, and ringback equipment for applying
ringback signals having a preselected frequency and duration to a
calling customer line addressing an idle called customer station,
said method comprising the steps of:
detecting the application of .Iadd.a .Iaddend.ringback
.[.signals.]. .Iadd.signal .Iaddend.to a selected calling customer
line which is selected by selecting a calling customer line
addressing a called customer line connected with a switching system
different from the switching system to which the calling customer
line is connected;
applying said messages to the selected calling customer line
between successive ringback signals in a manner to bypass
.[.said.]. .Iadd.an associated .Iaddend.switching network; and
terminating said messages when the ringback signals are terminated.
.Iadd.
13. A method according to claim 6 wherein the step of applying also
includes superimposing said messages over said ringback signal
during application of said ringback signal.Iaddend.. .Iadd.
14. In a telecommunications system having a plurality of switching
means interconnected by trunk means, a plurality of stations
arranged in groups with each group being served by a switching
means, lines connecting said switching means with the group of
stations served thereby, said switching means comprising switching
network means for establishing a communication path between a
calling station and a station addressed by the calling station, and
means for applying a ringback signal to the lines connected to said
calling station when a called station addressed by the calling
station is on hook, the improvement comprising:
detection means for detecting lines to which ringing signals have
been applied;
storing means for storing communication signals;
control means for associating said communication signals with
designated stations;
comparing means for comparing telephone numbers addressed by
calling stations with telephone numbers of said designated
stations;
communication signal applying means for applying said stored
communication signals to a calling line during the ringback period
in response to detection by said detection means that a ringback
signal has been applied thereto if said comparing means indicates
correspondence of identity of the station addressed by the calling
station of the detected calling line with one of said designated
stations. .Iaddend. .Iadd.15. The improvement of claim 14, wherein
said ringback signal is a periodic signal having successive
ringback tone signal portions each of a preselected frequency and
duration, and said communication signals are applied between
successive ringback tone signal portions. .Iaddend. .Iadd.16. The
improvement of claim 15, wherein said communication signals are
applied only between successive ringback tone signal portions.
.Iaddend. .Iadd.17. The improvement of claim 15, wherein said
communication signals are also applied superimposed on at least one
of said ringback tone signal portions. .Iaddend. .Iadd.18. In a
communications system having a plurality of switching means
interconnected by trunk means, a plurality of stations arranged in
groups, the stations of each group all being connected to a
corresponding one of said switching means by respective lines,
switch hook means for each station for determining whether the
station is on hook or off hook, switching network means in each
switching means for establishing a communication path between a
calling station and a called station, means associated with said
switching means for applying a periodic ringback signal to a
calling station line when the called station is on hook, and means
for terminating the ringback signal when the called station goes
off hook to respond to the call, message applying means
comprising:
a message storing means associated with each said switching means
for storing at least one message:
a message applying means associated with each said switching means
for applying said at least one message to a selected line served by
the associated switching means in response to detection that a
ringback signal has been applied to said selected line if a station
connected thereto has addressed a called station that corresponds a
predesignated called station; and
means for controlling said message applying means to terminate
application of said at least one message when the addressed called
station goes off hook. .Iaddend. .Iadd.19. A method of applying
messages to stations in a telecommunications network in which the
stations are connected by lines to switching means having trunk
connections with other switching means, switching network means
associated with each switching means for establishing
communications paths between calling stations and called stations,
and ringback means for applying a periodic ringback signal, having
successive intervals each of a preselected frequency and duration,
to a calling line of a calling station addressing an idle called
station, said method comprising the steps of:
(a) detecting the application of a ringback signal to a selected
calling line;
(b) determining whether a called station addressed by the calling
station of said selected calling line recited in step (a)
corresponds to a predesignated called station;
(c) applying said messages to the selected calling line recited in
step (a) between successive ringback signal intervals in a manner
to bypass said switching means in response to a ringback detection
as recited in step (a) if there is a determination of
correspondence as recited in step (b); and
(d) terminating said messages when the ringback signal is
terminated.
.Iaddend. .Iadd.20. A method according to claim 19 wherein said
step of applying further includes superimposing said messages on at
least one
ringback signal interval. .Iaddend. .Iadd.21. A method of applying
messages to stations in a telecommunications network in which the
stations are connected by lines to switching means having trunk
connections with other switching means, switching network means
associated with said switching means for establishing
communications paths between calling stations and called stations,
and ringback means for applying a periodic ringback signal, having
successive intervals each of a preselected frequency and duration,
to a calling line of a calling station addressing an idle called
station, said method comprising the steps of:
(a) detecting the application of a ringback signal to a selected
calling line;
(b) determining whether a called station addressed by the calling
station of said selected calling line recited in step (a)
corresponds to a predesignated called station;
(c) applying at least one of said messages to the selected calling
line recited in step (a) said ringback signal is applied for
delivery to said calling station in response to a ringback
detection as recited in step (a) if there is a determination of
correspondence as recited in step (b); and
(d) terminating said at least one of said messages when said called
station goes off hook to complete a connection to said calling
station. .Iaddend.
Description
BACKGROUND OF THE INVENTION
This invention relates in general to the field of
telecommunications and deals more particularly with a method and
apparatus for applying messages and other communication signals to
telephone lines.
Telecommunications networks include customer stations (typically
ordinary telephone sets) which are linked together via switching
centers in order to provide communication paths between the calling
station and the called station. The switching center is usually a
telephone company facility commonly known as a "central office",
although it can also be a toll office, a private branch exchange
(PBX) or a key telephone system. The switching function of the
switching center is performed by a switching network which is
controlled by a control complex and which at times switches various
service circuits into the communication path. The service circuits
include wrong number announcements and changed number
announcements, digit receivers, tone generators and other
peripheral equipment that performs specialized service functions.
The transmission lines include customer lines which connect each
customer station with a switching system and trunks which connect
the switching systems with one another.
Telephone call setup involves, as the first step, the calling party
taking his telephone "off hook", thus closing the switch hook
contacts of the telephone to inform the local switching system of a
request for service. The control complex of the switching system
then applies a dial tone signal to the calling line and prepares to
accept the digits that are to be dialed. When the number addressed
by the calling customer station is dialed, the digits are accepted
and interpreted by the control equipment at the central office. The
initial digits (usually the first three) provide information as to
whether the called station is serviced by the same or another
central office. If the call is an inter-office call, the
originating office selects an idle trunk to the terminating office
if one is available.
When an available trunk is seized, it is connected with the calling
customer's line through the switching network in the originating
central office. The digits of the called number are then
transmitted over the trunk to the terminating central office which
determines the status of the called customer's line. In modern
"common channel signaling systems", the called number is changed to
a digital data message and sent over a separate circuit referred to
as a "common channel signaling circuit". If the telephone at the
called station is busy (off hook), an audible busy signal tone is
applied to the calling party's line. If the called telephone is
idle (on hook), a ring signal is applied to its customer line for
activating the ringer in the called party's telephone. At the same
time, a different but similar ringback signal is applied to the
calling party's customer line by the ringback equipment in the
terminating central office. In the newest "common channel signaling
systems", a digital data signal to the originating central office
may activate the application of the ringback signal to the calling
party's line. The ringback signal is applied at 440 and 480 Hz, and
takes the form of audible tones which are applied for a duration of
two seconds each with an interval of 4 seconds between successive
tones.
If the called telephone is answered, its off hook status causes
termination of the ringback signal. At the end of the conversation,
the telephones are returned to on hook status, and the customer
lines and trunk revert to idle status. Intra-office calls are
processed similarly, except that there is no need for seizure of a
trunk because the call can be routed through the switching network
in a single central office.
In recent years, telephone transmission facilities have been used
to transmit various types of data in addition to ordinary telephone
conversations. For example, it is now common for computers to
communicate via telephone transmission lines. Facsimile machines
and other modern machines transmit information over telephone
lines. Stock market information, weather data, commodity prices,
news and other data are also often transmitted by telephone. It is
also common for music and/or commercial messages or announcements
to be applied to telephone lines, especially when a party is placed
on "hold" while waiting to speak to someone. However, to my
knowledge, telephone lines have not been used to transmit messages
or data during the ringback period when the calling party is
waiting for the called party to answer.
SUMMARY OF THE INVENTION
It is the principal object of the present invention to provide a
method and apparatus for applying messages to calling parties
during the times when the calling party is receiving ringback
signals while waiting for the called party to answer a call. By
making use of this heretofore unused time, the telephone network
facilities are utilized more effectively for the transmission of
information. At the same time, messages are transmitted only during
times when the telephone line is already occupied, so there is no
increase in the extent to which available lines are tied up.
In accordance with the invention, messages such as recorded
commercial advertising messages are applied to the customer lines
of calling parties during the ringback period when the customers
are waiting for a call they have placed to be answered. The
equipment for implementing the system is located in the switching
centers and usually includes a ringback detector which detects the
application of a ringback signal to the calling customer's line. A
timer is then activated to control the application of a recorded
message to the line in a manner to assure that messages are applied
between ringback tones and discontinued during the tones. In this
manner, the messages are clearly heard by the calling party without
interfering with the ringback signal. The messages are terminated
when the called party answers the call and goes off hook. It is
also possible for messages to be applied during ringback tones as
well as between them, although it is usually not desirable to
superimpose a message over a ringback tone.
A ringback detector is not necessary if the call is an intra-office
call. The switch already knows precisely when ringing tone is
applied and interrupted (The ringback signal is usually interrupted
by a device called an interrupter).
The message application equipment of the present invention can be
connected with the telecommunications network at various locations
and in various ways. For example, the equipment can be bridged onto
the calling party's customer line in the existing switching network
of the central office or PBX. Then, the equipment functions much
like other service circuits and is switched onto the calling
customer lines by the existing switching network. The switching
network can be programmed to switch the equipment onto selected
lines which can be determined in a number of ways, such as
according to the identity of the called party or calling party.
Alternatively, the message applying equipment can be bridged onto
selected customer lines between the customer station and the
terminal interface in the central office Another alternative is to
bridge the equipment onto the trunks such that messages are applied
only for inter-office calls. The equipment can also be connected in
the service circuit complex such that an audible ringback signal
and a recorded message are applied to all calls. Still another
possible alternative is to connect the equipment between the
terminal interface and switching network.
As previously suggested, it is preferred that messages be applied
to only selected customer lines, although the system can be
implemented to transmit messages to all callers. In one possible
application of the system, the telephone company can give customers
the option of paying reduced rates (subsidized by advertisers) or
paying full rates without commercial messages being transmitted on
their lines. Some customers will elect the lower rates and some
will not, so it is desirable to be able to select which customer
lines are to receive messages. As another example, if a particular
airline has commercial flights from Chicago to New York, the
airline may want to advertise only to callers in Chicago who call
the New York area (thinking that they are more likely to fly to New
York than the general population). Again, only certain callers
would receive commercial messages, and these callers would be
selected according to the identity of the called party (identified
by the area code of the dialed number or by the long distance
company chosen by a customer in what are known as "equal access"
central offices).
The system is especially well suited for local advertising because
the advertising messages are applied to callers that are linked to
a particular central office or PBX. Local, political and civic
messages are also possible; i.e., "vote for Jones for Mayor". In
addition, corporate messages and announcements can be made in PBX's
or private switching systems; i.e., "turn in time sheets on Monday"
or "Jones has been promoted to company Vice President". The
transmission of stock market information, the latest news or
weather, musical notes or virtually any other type of data can be
carried out in accordance with the present invention, and this
makes effective use of the telecommunications systems during times
that are otherwise not used to advantage.
DESCRIPTION OF THE DRAWINGS
In accompanying drawings which form a part of the specification and
are to be read in conjunction therewith and in which like reference
numerals are used to indicate like parts in the various views:
FIG. 1 is a functional block diagram of a typical telephone company
switching center or PBX.
FIG. 2 is a functional block diagram of a switching center equipped
with a message applying system implemented according to a preferred
embodiment of the present invention;
FIG. 3 is a functional block diagram of a switching center equipped
with a message applying system implemented according to another
embodiment of the present invention;
FIG. 4 is a functional block diagram of a switching center equipped
with a message applying system implemented according to still
another embodiment of the invention;
FIG. 5 is a functional block diagram of a switching center equipped
with a message applying system implemented according to yet another
embodiment of the invention; and
FIG. 6 is a functional block diagram of a switching center equipped
with a message applying system implemented according to still
another embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings in more detail and initially to FIG.
1, numeral 10 generally designates a conventional switching system
which is typically a telephone company central office but which may
be a key telephone, a private branch exchange (PBX) or another type
of switching center. Individual customer stations 12 are equipped
with terminal equipment which is typically a conventional telephone
set. The customer stations 12 are connected with the switching
system 10 by individual customer lines 14 which are typically
paired wires forming a loop when connected through the switchhook
contacts of the telephone set at the customer station. The
switching system 10 supervises the customer lines 14 to determine
whether the line is idle (on hook) or busy (off hook).
The switching system 10 is provided with three main functional
equipment groups and with various auxiliary groups, depending upon
its particular application. The main groups of equipment include
the terminal interface 16 which is used to connect all of the
customer lines 14 with the switching system 10 and also to connect
all trunks 18 to the switching system. The trunks 18 are
transmission lines or paths which connect the switching system 10
to other switching systems such as other central offices or PBX's.
The second main equipment group in the switching system is a
switching network 20 which provides communication paths between the
various customer lines 14 and trunks 18. The switching network 20
is connected with the terminal interface 16 by transmission paths
22. The third main group of equipment is the control complex 24
which controls all other functions.
The peripheral equipment of the switching system 10 includes
various service circuits 26. The service circuits are special
equipment such as dial tone generators, digit receivers, ringback
tone generators, busy tone generators, wrong number announcements
and changed number announcements. The appropriate service circuit
is switched into the communication path by the switching network 20
under the control of the control complex 24.
The control functions performed by the switching system 10 are
manifold. The customer lines 14 are supervised to determine
transitions from idle to busy, thus indicating a demand for
service. The calling customer line is identified for billing
purposes, and a path is established through the switching network
20 to an idle digit receiver in the service circuits block 26. At
the same time, a tone generator in the service circuit block is
bridged onto the line and activated to transmit a dial tone to the
calling customer line. When the first digit of the called party
address is received, the dial tone generator is disconnected, and
the digit is registered. The remaining digits of the address are
received and interpreted, and the digit receiver is then
disconnected.
The address is translated into a designation of the equipment
termination of the called line (or trunk if the call in an
inter-office call), and the called line is tested to determine
whether it is in an idle or busy status. If the called address is
busy, the calling customer line is connected to a busy tone
generator through the switching network 20. When the calling party
then hangs up the phone and reverts to "on hook" status, the
connection is broken.
If the called line is idle, an idle path through the switching
network is searched and, if an idle path is available, it is
reserved, the called line is connected to a ringing generator, and
the calling line is connected to an audible ringback tone. The
ringback tone is applied by a ring back generator which applies the
ringback tone at 440 or 480 Hz. Each ring back tone has a duration
of 2 seconds, and there is an interval of 4 seconds between
successive ringback tones.
When the called party answers the call by going off hook, the
terminal interface equipment 16 detects the off hook condition, and
the control complex 24 then causes disconnection of the ringing
generator and the audible ring back generator. The calling and
called lines are connected through the switching network 20 along
the path that has been reserved. The network path remains
established for the duration of the call. When either party goes
back to hook, the transition from off hook to on hook status is
detected by the terminal interface equipment 16, and the control
complex 24 disconnects the network path and restores the lines to
the idle state.
If the call is a distant call requiring connection through another
switching system connected with the called line, the control
complex 24 in the originating switching system searches for an idle
trunk to the distant (or an intermediate) office. If found, the
address digits are transmitted to the distant office and the
calling line is connected to the trunk through the switching
network 20 in the originating office. The on hook detection and
disconnect operation occur in substantially the same manner as for
a local call that is routed through a single switching system.
The switching network 20 establishes the communication paths
between the calling and called lines or between the calling line
and an available trunk which leads to the terminating central
office The switching network 20 can use either space division
switching techniques or time division techniques. The switching can
take place by the action of mechanical switches, although stored
program controlled digital switching is more often used in modern
switching systems.
As thus far described, the telecommunications network and the
switching system 10 are conventional.
In accordance with the present invention, the switching system 10
is equipped with a message applying device which is shown in block
diagram form in FIGS. 2-6 and generally designated by numeral 28.
With specific reference to FIG. 2, the device 28 includes a
conference circuit 30 which may be digital or analog and which is
bridged onto the telecommunications network to couple device 28
with the switching system 10. The conference circuit 30 is
connected with a ringback detector 32 which serves to detect the
application of ring back signals to calling customer lines 14. It
should be noted that the ringback detector is not necessary on an
intra-office call. A control complex 34 in device 28 controls its
functions in much the same manner as the control complex 24
controls the equipment in the switching system 10. A recorded
message announcement device 36 contains recorded messages which are
to be applied by the device of the present invention. A timing
circuit 38 functions to time the application of the recorded
messages such that they are applied between ringback tones, as will
be explained more fully.
The recorded message announcement device 36 may be a device of the
type marketed by the Cognitronics Company under the trade
designation SRA. The SRA device is a single channel, microprocessor
control, digital intercept announcer that applies voice messages to
telephone lines. It should be noted that other recorded message
announcers can be used as well, including digital read only memory
(ROM) chips, compact disks, cassette tapes or other storage
buffers.
In the implementation of the invention illustrated in FIG. 2, the
conference circuit 30 is connected with the switching network 20 by
a transmission path 40. In this implementation, device 28 functions
in a manner similar to the service circuits 26. The switching
network 20 switches the transmission path 40 onto a calling
customer line 14 which is attempting to place a call to another
customer, either local or remote. The switching network 20 can be
programmed to switch the transmission path 40 onto the customer
lines of al calling parties or only selected customers. The
selected customer lines which are to receive messages may be
selected according to the identity of the calling customer, as by
switching the transmission path 40 onto calls placed from customer
stations having a particular prefix or telephone number or any one
of a number of prefixes or numbers. Alternatively, the switching
network 20 can be programmed to switch the transmission path 40
onto calling customer lines 14 in accordance with the identity of
the called party (or the calling path's designated long distance
carrier in an "equal access" central office). In this instance, the
area code or prefix of the dialed number (or the code of the
designated carrier) determines whether or not the transmission path
40 is switched onto the calling party's line.
In operation of the system, when a calling customer at one of the
customer stations 12 goes off hook and dials a number which
addresses a customer to be called, the audible ringback equipment
in the service circuit block 26 is switched onto the calling
party's line during the time when the ring signal is being applied
to the called party. If the program of the control complex 24
indicates that the calling party is to receive a recorded message,
the transmission path 40 is switched onto the communications path,
and the ringback detector 32 detects the ringback signal that is
being applied to the calling party line (except in the case of an
intra-office call when the ringback detection is not required). The
control complex 34 then activates the message announcer 36 in order
to initiate the application of a recorded message to the line of
the calling party. The timer 38 performs the timing function of
assuring that the messages in the announcer 36 are initiated at the
end of a ringback tone and terminated prior to the beginning of the
next successive ringback tone. In this manner, the timer 38
functions to prevent the messages from being applied at the same
time as a ringback tone is generated. However, it should be
understood that in some instances, a recorded message can be
superimposed on a ringback tone without significant adverse
effects.
The messages that are contained within the announcer 36 are applied
along the transmission path 40 and are routed through the switching
network 20 and the terminal interface 16 to the calling customer
line 14. During the ringback period while the calling customer is
waiting for the called customer to answer the call, one or more
recorded messages are thus transmitted to the calling customer
Examples of the types of messages that can be applied are
commercial advertising messages such as "fly XYZ airline" or "buy
ABC widgets", Political announcements such as "vote for Jones for
Mayor" can also be transmitted to calling customers. In addition,
music, stock market information, commodity pricing information,
news or weather data, or virtually any other kind of data can be
transmitted to the calling customer during the ringback period. The
announcement device 36 applies voice frequency tones on the
telephone lines so that the messages are intelligible to the
calling party. Alternatively, tones that are detected by computers
or other equipment can be applied. The band pass range on telephone
lines is approximately 0-4000 Hz.
Preferably, each message in the announcer 36 has a duration of
approximately 4 seconds which is the interval between successive
ringback tones. This permits a complete message to be transmitted
during each interval (or during every other interval or every third
interval). It has been determined empirically that three or four
ringback tones are generated during the average telephone call.
Consequently, it is possible for a complete eight second message to
be transmitted, with half of the message occurring between the
first two ring back tones and the second half of the message being
applied during the interval between the second and third tones. It
is also possible that only a single message lasting four seconds or
less will be applied during any one call attempts. It is also
possible for messages to be superimposed on ringback tones, as
previously suggested.
When the called party goes off hook to answer the call, the answer
detect equipment in the switching system 10 detects the off hook
status of the called party and switches the ring generator and the
ringback tone out of the communications path (except in the case of
intra-office call when the control complex 24 will automatically
disestablish path 40 through the switching network 20 upon answer).
At the same time, the transmission path 40 is switched out of the
communications path by the switching network 20 under the control
of the answer detecting equipment. In this manner, the recorded
messages are terminated when the called party answers the
telephone.
It should be understood that multiplexing techniques and other
techniques can be used to permit recorded messages to be applied to
more than one customer at a time. Different messages can be applied
at different times of day or different days of the week or month,
and different messages can be applied to different customers
selected according to their identity or the identity of the party
they are attempting to call, or by the identity of the long
distance company they have chosen in "equal access offices". In
this way, commercial and political messages can be targeted for
particular customers or types of customers to whom the advertising
party wishes to reach. It is also noteworthy that all of the
calling customer stations 12 are local to the particular switching
system 10, and the system is thus well suited for local
advertising, commercial, political or otherwise. Regional or
national advertising is also possible. Because of the frequency
with which telephone calls are made, the potential audience that
can be reached is huge. It is also important to note that since
detailed call records are available, advertisers can be informed of
exactly which callers have received their messages and when, thus
providing "harder" information than results from the statistical
techniques typically used in the AM/FM broadcast industry.
Referring now to FIG. 3, the implementation of the message applying
device 28 differs from the implementation shown in FIG. 2 in that
the FIG. 3 arrangement involves connection of the conference
circuit 30 directly to one or more selected customer lines 14 along
transmission path 42. In this implementation, the customers who are
to receive messages are directly selected and directly connected to
the transmission path 42 (preferably by switching). It is noted
that the implementation shown in FIG. 3 does not involve connection
of device 28 to the telecommunications network through the
switching network 20. Accordingly, the device 28 shown in FIG. 3 is
equipped with its own answer detect equipment 44 which detects the
off hook status of the called party in order to terminate the
message at that time.
The implementation of the invention shown in FIG. 3 is particularly
well suited for a situation where the identity of the calling party
is used to determine whether or not a message is to be applied. The
selection can be carried out conveniently simply by connecting the
transmission path 42 to those customer lines 14 or stations 12
which are selected and not making the connection with customer
lines or stations 12 which are not to receive messages.
FIG. 4 shows another implementation of the invention in which the
conference circuit 30 of device 28 is connected with one or more of
the trunks 18 by transmission path 46. Again, the answer detect
equipment 44 is required since the transmission path 46 bypasses
the switching network 20. In this implementation, messages are
applied only to inter-office calls and perhaps only to calls made
to particular selected distant offices. The transmission path 46
can be connected to all of the trunks 18 for the switching system
or only to the trunks of selected offices. In any event, all calls
that go through a trunk to which path 46 is connected activate the
device 28 and result in the application of a message to the calling
party making the inter-office call.
In the implementation of the invention shown in FIG. 5, the audible
ringback generator 48 which is included in the service circuit
block 26 is connected with the switching network via line 50. The
conference circuit 30 of device 28 is connected directly with path
50 along transmission path 52. Accordingly, whenever an audible
ring back signal is being applied along line 50 to a calling
customer, device 28 is activated and applies messages which
accompany the ringback tones. In this implementation, all calling
parties served by the audible ringback generator 48 receive
messages during the ringback period.
The implementation of the invention shown in FIG. .Iadd.6
.Iaddend.involves connection of the conference circuit 30 with the
transmission path 22 which extends between the terminal interface
16 and the switching network 20. Transmission path 54 extends from
the conference circuit and is tied to transmission path 22. Again,
whenever any calling party is receiving ring back tones, the device
28 is activated to apply recorded messages to the calling party's
line.
It is contemplated that telephone companies will make charges to
advertisers or others who wish to use the telephone network to
transmit recorded messages to callers. The additional revenue
received by the telephone company can be used to reduce telephone
rates in general. Alternatively, customers can elect whether or not
to receive the service. If they elect to receive recorded messages,
their rates can be reduced. Those that elect to forego the service
will pay the full rate. In this situation, it is necessary to be
able to select which calling parties are to receive messages and
which are not. Consequently, the implementations shown in FIGS. 2
and 3 are preferred. In situations where the application of a
message is dependent upon the identity of a called party, (or the
calling party's long distance carrier), the implementation of FIG.
2 is preferred since the switching network can be programmed to
apply an announcement for all calls directed to a particular are a
(as determined by the area code or prefix digits or a particular
long distance carrier).
It is thus apparent that the method and apparatus of the present
invention takes advantage of essentially wasted time during
telephone call setup to make use of the existing telephone
facilities for the transmission of information which may or may not
be of a commercial nature. Weather, news and other informational
messages can be transmitted, as can civic announcements and other
similar types of messages. In addition, music or virtually any
other voice frequency tones can be transmitted. It is also to be
noted that data within the telephone line bandpass frequency range
can be transmitted to the calling party during telephone call setup
and received by a modem or other suitable equipment.
From the foregoing, it will be seen that this invention is one well
adapted to attain all the ends and objects hereinabove set forth
together with other advantages which are obvious and which are
inherent to the structural.
It will be understood that certain features and subcombinations are
of utility and may be employed without reference to other features
and subcombinations. This is contemplated by and is within the
scope of the claims.
Since many possible embodiments may be made of the invention
without departing from the scope thereof, it is to be understood
that all matter herein set forth or shown in the accompanying
drawings is to be interpreted as illustrative and not in a limiting
sense.
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