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CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to the application of Alexander C. Gillon, Adam
V. Reed, and John M. Scanlon entitled "Improved Facsimile Service", Ser.
No. 309,586 filed Feb. 10, 1989. This application is also related to the
application of Nancy A. Catron, Joseph V. Fodale, Karrie J. Hanson, Robert
A. Koch, Ronald E. Large, and Susan M. Zoccolillo entitled "Improved
Facsimile Service", Ser. No. 399,384 filed Aug. 24, 1989.
This application is related to the application of Nancy A. Catron, Joseph
V. Fodale, Karrie J. Hanson, Robert A. Koch, Ronald E. Large, and Susan M.
Zoccolillo, Ser. No. 399,384, entitled "Improved Facsimile Service", a
continuation-in-part filed Aug. 24, 1989, of an application Ser. No.
358,743 filed May 30, 1989, now abandoned.
TECHNICAL FIELD
This invention relates to facsimile service and other specialized types of
telecommunications calls.
PROBLEM
Facsimile service is becoming increasingly popular because of the wide
availability of relatively inexpensive facsimile machines. Facsimile (fax)
service however still presents some problems. One common problem is
attempting to send a facsimile message to a customer whose telephone
number is known but whose facsimile number is not known. Under these
circumstances, a separate call is typically required to identify the
customer's facsimile number. This is wasteful of the calling and called
customer time and is also expensive since an extra call is required.
International facsimile calls ideally should be transmitted over selected
circuits with low distortion since conventional facsimile signals may be
excessively distorted over many other international voice transmission
facilities. Getting access to such selected circuits presents a problem.
Advances in fax service now enable a customer encountering a busy or
ring-no-answer condition on a fax call to send a facsimile message to a
store and forward facility for subsequent transmission to the destination
facsimile machine when that facsimile machine is available. However, such
service reorigination involves a time consuming process in order to call a
store and forward facility and to redial the called number into that
facility for subsequent fax delivery. In view of the foregoing, needs
exist in the art to process fax calls to a fax machine without the caller
dialing the fax number, to process international fax calls over special
low distortion circuits, and to simplify the process of sending calls to a
store and forward facility. Similar needs are encountered in other types
of specialized telecommunication calls such as calls to a recipient voice
messaging system and electronic mail system.
SOLUTION
The foregoing needs are met and an advance is made over the prior art in
accordance with the principles of this invention wherein in an
illustrative embodiment, facsimile calls are processed to a fax
destination by class of service marks, illustratively, a flag in a call
set-up common channel signaling (CCS) message, for special treatment in
their processing through a common carrier network. The calls are
illustratively recognized as being fax calls by a prefix comprising a
special alternative common carrier code such as 10XXX or a non-numeric
indicator such as the # sign or a # sign plus one or more digits keyed on
a dual tone multi-frequency (DTMF) customer station dialed by the customer
and recognized in the network as designating a fax call, or by a fax mark,
data sent along with a message to set up a connection, from an integrated
services digital network (ISDN) line. Advantageously, such a class mark
permits a number of special fax features to be implemented, including
automatic transfer of fax calls from the number of a called voice station
to an associated fax number, automatic routing of international fax calls
over selected facilities, and automatic conversion of a conventional fax
call to a store and forward call on busy or on ring-no-answer condition.
If a call is recognized as being a fax call, the fax caller may dial a
conventional (voice) telephone station line and have that call connected
automatically to a fax machine serving that station line instead of its
telephone. That action is achieved by recognizing a fax traveling class
mark at a destination switching office controller or processor or network
control point processor, having that processor consult a memory to derive
a fax destination number serving the called party, and then controlling
the routing of the fax call to that fax destination instead of the
telephone identified by the dialed number. When this happens, a fax
message waiting indication may be activated on the called voice phone.
Another feature of the invention is that when a facsimile call is
recognized, a receiver is attached to the call to detect if the calling
customer dials additional digits for requesting a store and forward
connection. The customer may dial such additional digits in response to
hearing that the called facsimile number is busy or detecting that the
called facsimile number does not answer. When the additional digits are
detected, the call is routed to a store and forward facsimile facility and
the previously dialed called number and the originating customer's number
are automatically forwarded to that store and forward facility for
delivery of the call, delivery of a confirmation, and for billing.
Alternatively, the network can automatically forward calls from that
calling customer to a store and forward facility on busy or ring-no-answer
condition.
Another feature of this invention is that the called customer may specify
that fax calls to busy or ring-no-answer condition be automatically
rerouted to a fax store and forward facility. On international fax calls,
the invention provides facilities in an international gateway switch to
ascertain that the call is a facsimile call and automatically to route the
call over selected low distortion transmission facilities for quality
communication. Further, a translation from the voice number to an
associated fax number is made at the gateway switch, either directly or by
accessing a shared database, to provide automatic routing to an associated
fax machine for countries which have not implemented automatic rerouting
of calls from voice to fax machines. For Direct Services Dialing
Capability (DSDC) calls, such as "800" or "Freephone" calls, a DSD Network
Control Point, a database shared by a plurality of Interexchange Carrier
(IXC) switches, provides the necessary data for processing calls in
accordance with the principles of this invention.
More generally, a large number of calls, consisting of several broad
classes of specialized calls, can be handled advantageously by permitting
a routing to a destination other than the nominal destination based upon
the type of the call. Examples of types of calls are facsimile calls,
calls directly to the voice messaging system serving the intended
recipient, and calls to the electronic mail system serving the intended
recipient. The type of the call can be established automatically,
illustratively, in the local switch from either the line equipment
appearance number of the calling line or the directory number of the
calling customer (and communicated from a local switch to an IXC switch
via information digits), and in an IXC switch on the basis of the calling
customer directory number as forwarded through automatic number
identification facilities or through additional digits collected from the
originator of a call in response to a network provided prompt.
Accordingly, this invention is an arrangement for recognizing fax calls by
a special prefix or an indicator in a data message from customer
equipment, and responsive to such recognition, to automatically transfer a
fax call to a voice destination to the fax machine associated with that
voice destination. A fax call indicator, such as a traveling class of
service mark in CCS messages for the call, is used to communicate that the
call is a fax call to switching offices and NCPs for that call.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an overall block diagram of an interexchange carrier system for
implementing applicants' invention;
FIGS. 2 and 3 are memory layouts of databases of interexchange carrier
switches used for processing calls; and
FIGS. 4 and 5 are flow charts of programs for controlling actions required
to implement applicants' invention in an interexchange carrier ingress and
egress switch, respectively.
DETAILED DESCRIPTION
FIG. 1 is a block diagram showing major elements required to implement
applicants' invention. Three facsimile machines are shown, originating
facsimile machine 102, originating facsimile machine 101, connected to an
ISDN termination 105, and terminating facsimile (fax) machine 104. In
accordance with one specific embodiment, each such machine is "registered"
with the carriers serving the customer, and, as indicated below, data is
recorded in the appropriate switches that the customer's line is, in fact,
connected to a fax machine. Each of these machines has an associated
telephone number. Originating facsimile machine 102 is connected to
serving local exchange switch 106, and originating fax machine 101 is
connected to local exchange switch 107 equipped to support ISDN. The
number of the originating facsimile machine 102 is referred to hereinafter
as the calling number and is the number identified by Automatic Number
Identification (ANI) at the connected local exchange carrier (LEC) switch
106. ANI is also provided for fax machine 101 in order to verify that the
associated customer has subscribed to the service.
The terminating facsimile telephone number will be referred to hereinafter
as the associated facsimile number; in this example, the caller at
facsimile machine 102 or 101 does not know the telephone number of
facsimile machine 104 but instead knows only the voice telephone number of
a customer who is served by facsimile machine 104. However, as discussed
infra, the interexchange carrier network has information stored in a table
to translate from that voice telephone number to the number of fax machine
104.
When originating facsimile machine 102 places a call to a called number
(the number of the voice telephone of the customer to whom a facsimile
message is to be sent), the called number and the number of facsimile
machine 102, identified by ANI facilities in local exchange carrier switch
106 and hereinafter referred to simply as the ANI number, are sent to
ingress interexchange carrier (IXC) switch 110. In this specific
embodiment, the IXC switches are 4 ESS.TM. switches, described in The Bell
System Technical Journal, Vol. 56, No. 7, September 1977, pages 1015-1320.
Signaling between LEC switch 106 and IXC switch 110 is carried out using
Feature Group D signaling which permits the signaling of ANI data. Feature
Group D signaling is specified in Bellcore document: Notes on the BOC
Intra-LATA Networks-1986, Technical Reference TR-NPL-00275, Issue 1, April
1986, Section 6. The IXC switch 110 comprises a switching network 112 for
interconnecting communications ports, a processor 114 for controlling the
operations of the switch, dual tone multi-frequency (DTMF) receivers 117
for receiving DTMF signals from fax machine 102, MF receivers 116 for
receiving signals from local exchange carrier switch 106, a common channel
signaling (CCS) transceiver 118 for transmitting messages to other IXC
switches, and a database 120, shown in FIG. 2, for storing, among other
items, a table 122. The table 122 stores ANI numbers associated with
facsimile machines served by switch 110 and, for each such facsimile
machine, an indicator of whether store and forward service is offered to
that machine, an indicator of mixed use service, and an indicator of
automatic connection to store and forward on busy or on ring-no-answer
condition.
More generally, a number of methods can be used for identifying that a call
is a fax call. The customer at machine 102 may also signal a fax call by
dialing a special prefix, illustratively a special common carrier
identification prefix, which is recognized at local exchange 106 or
ingress switch 110 as designating a fax call. The ingress switch responds
to this prefix, either received from the customer via local exchange
switch 106, or transmitted in the form of a special signal from switch
106, by treating the call as a fax call as described hereinafter. The
customer at fax machine 101, connected to local exchange switch 107 by an
integrated services digital network (ISDN) connection, automatically
signals a fax call via a fax indicator 109 in a call setup message 111 to
switch 107. Switch 107 passes on a fax indicator 115 in a signaling
message 113 to ingress switch 110. The presence of fax indicator 115 is a
signal to switch 110 that the associated call is a fax call.
Other methods of recognizing a fax call include a class of service
translation performed at an originating office to recognize that the call
is from a fax machine. This class of service is then transmitted to an
ingress switch by information digits as described hereinafter;
alternatively, the information can be transmitted in a CCS message.
Another method of recognizing a fax call is by a prefix such as #, # plus
one or more digits (for example, #3=#F), or an alternative common carrier
code such as 10XXX. The local office recognizes this prefix and signals
the prefix to a toll carrier in one of the ways described above, or simply
passes the prefix as well as the rest of the digits to the ingress switch.
When an incoming call from LEC switch 106 is detected in switch 110, the
call is connected through network 112 to an MF receiver 116 to receive the
called number and the ANI number transmitted from switch 106. Processor
114, operative under the control of program 119, records these digits as
they are received and checks in database 120 to see if the ANI number
corresponds to a facsimile machine, or whether the ANI number corresponds
to a mixed use line. The treatment of mixed use lines is discussed
hereinafter with reference to FIG. 4, blocks 230 and 232. In this case,
the ANI number corresponds to facsimile machine 102 which, it is assumed
for the purposes of this description, also has a store and forward
indicator indicating that this machine has subscribed for store and
forward service. The database 120 also includes screening data to prevent
a particular ANI from making toll calls outside a particular range, or
from making international calls. If the call is destined for a Direct
Service Dialing Capability (DSDC) subscriber service such as "800" or
Freephone service, then processor 114 queries the appropriate DSD Network
Control Point (DSD/NCP) 121 as in the prior art to obtain the correct
processing information and in addition will also do the additional
processing and information retrieval for called party initiated features,
such as voice to fax translation and redirect to store and forward for
example. This information must be passed to the egress IXC via fields in
message 140. Calls that are screened are simply not accepted and the
caller receives a disconnect.
After the call has been received in switch 110, the call is routed toward
an egress IXC switch 150 which can access the LEC switch 170 which serves
the called number. It is assumed in this case that the connection must go
through an intermediate IXC switch 182 in order to reach egress IXC switch
150. A CCS message 140 is sent to intermediate IXC switch 182 using CCS
transceiver 118 and controlled by processor 114. The message 140 comprises
segment 142, containing the ANI number, segment 144 containing a fax flag
indicating that this is a call originated from a fax machine, segment 146
comprises the called number, and segment 148 comprising an identifier for
identifying the call. Such a message is sent for any call recognized as
being a fax call, regardless of whether the originating customer has
subscribed to a fax specific feature. Alternatively, two or more flags may
be used, a fax flag indicating that this is a fax call, and one or more
additional flags specifying calling customer fax features, such as routing
over preferred facilities or automatic rerouting. The preferred facilities
flag can be set in response to a class of service indicator, specifying
that the caller is willing to pay a premium to have fax calls routed over
preferred international facilities.
Intermediate IXC switch 182 receives the message over CCS facility and the
associated call over a transmission facility, and sets up an additional
connection to egress IXC switch 150 and transmits the message 140 to that
switch. Intermediate IXC switch 182 and egress IXC switch 150 are similar
to ingress IXC switch 110. The call is connected to network 154 of egress
IXC switch 150. The message 140 is received in CCS transceiver 152 of
switch 150. Processor 156 of switch 150, operative under the control of
program 157, examines message 140 and recognizes fax flag 144. Processor
156 then queries database 250, shown in detail in FIG. 3, of switch 150 to
access voice to fax (V-T-FAX) translation table 252. This table translates
from the called number such as 253 to the associated fax number such as
263 for LEC switches served by the egress IXC switch. The entries 253,
254, 255 may be either voice or fax numbers. Fax numbers are recognized
because the corresponding fax entry, 263, 264, 265 matches the voice or
fax number. In the example, a match is found between entries 255 and 265,
indicating that the directory number 255 is a number of a fax machine.
Customers with fax machines who do not need translation from a voice to a
fax number need not have an entry in table 252 since the call can be
completed normally whether or not a fax flag is present. If these
customers require special fax features, an entry such as 255 is used. For
voice numbers, a message waiting lamp indicator, such as 278, associated
with voice number 253, is available which, if set, causes a fax message
waiting lamp on the voice station to be lit when a fax call is received.
The message waiting lamp is lit via a data message sent from the egress
switch to a local switch connected to the voice line; this is particularly
straightforward if the voice line is an ISDN line.
The translation table also has an indicator 273 to specify whether the call
should be automatically routed to a store and forward facility such as
180, so that all overflow fax traffic can be recorded for subsequent
transmission to the desired fax terminal. In the case of a call whose
dialed number is a voice number, such as 253, egress IXC switch 150 then
forwards the associated fax number, not the called number, to store and
forward (S/F) facility 180. The call is then subsequently completed from
S/F facility 180 via IXC switch 150 to LEC switch 170 which serves
terminating fax machine 104. If fax machine 104 is available, the call is
set up. If the call is to a fax number such as 255, and the fax number is
busy, if the store and forward indicator 275 is set, the call is
forwarded. In an international gateway switching system, the V-T-FAX
translation is made for countries which have not implemented the features
of this invention. The translation may be stored either in the switching
system or in a remote database (not shown).
Database 250 can make a number of other translations besides voice to fax.
If completion to one of several fax numbers according to the time of day
or day of week is desired, or other more complex routing is desired, a
translation is made from a called number such as 254 to a pointer such as
264 which points to a block of memory 280. This block includes a number of
alternative destinations 281, 282, according to the time and/or day of
week 284, 285. In this case, one of the destinations, destination 282, is
a store and forward facility 180 for automatically storing the facsimile
message for subsequent delivery. The block also contains screening data
286 to block calls from certain numbers or to only permit calls from
certain numbers to be completed; this is useful, for example, for
shielding fax machines from receiving excessive "junk fax" messages.
Database 250 also comprises a block 290 for translations for international
calls to countries that have not implemented the voice to fax translation.
Entries 291, 292, 293 have corresponding translation results 296, 297,
298. Entries 291 and 292 represent voice numbers whose corresponding fax
numbers are 296 and 297. Entry 293 is a fax number as indicated because
corresponding entry 298 is the same. If the called number is not found in
block 290, it is assumed that the called number is a fax number and that
the call can be completed normally.
There exists a requirement that enhanced services (which includes store and
forward fax) must be capable of being provided by anyone. If fax machine
104 is either busy as indicated to the caller via busy message 172 sent
from egress IXC 150, or if fax machine 104 does not answer, then the
customer at fax machine 102 may key a group of DTMF signals for requesting
a store and forward connection. Because of the requirement, it is
necessary for the customer to key information for specifying a desired
store and forward carrier. For greater clarity, it is assumed in this case
that the store and forward carrier is one associated with the
interexchange carrier and therefore connected using switches of that
interexchange carrier. For further simplicity, it is assumed that the
store and forward facility 180 accessible from ingress IXC switch 110 is
also connected via intermediate IXC switch 182 and egress IXC switch 150
to facsimile machine 104. If the customer hears a busy tone or recognizes
that facsimile machine 104 is not answering, then the customer at
facsimile machine 102 keys data for specifying use of store and forward
facility 180 on this call. The connection from IXC switch 110 to fax
machine 104 is removed and instead facsimile machine 102 is connected via
IXC switch 110 to store and forward facility 180. Common channel signaling
message 190 is sent to store and forward facility 180. This message 190
includes segments 192 comprising the ANI number, 194 comprising the called
number, and optionally segment 196 for additional billing data such as a
subaccount billing number. Both the ANI number and the called number have
been retained in the memory of processor 114 and do not need to be
redialed or retransmitted to IXC carrier switch 110. The store and forward
facility 180 sends a fax flag along with fax call set-up messages. For
customers who prefer an automatic connection to a store and forward
facility on busy, the busy indicator 174 on CCS message 172 is used to set
up the connection to the store and forward facility automatically.
In case the recognized fax call is further recognized in ingress IXC switch
110 as being a Direct Services Dialing Capability (DSDC) call, a request
message similar to message 140 is sent to Direct Services Dialing/Network
Control Point (DSD/NCP) 121 with a fax flag 144 marked. The DSD/NCP 121
translates this request message using a database, comprising data similar
to that in database 250 for translating voice to fax numbers, and returns
a translated-to-fax number in a response message to switch 110.
Thereafter, the call is processed as if the translated-to-fax number had
been called by the calling station. If the called customer has any
terminating features such as redirect to another station or to store and
forward, the data describing these features is supplied in the response
message from the DSD/NCP 121 and is forwarded to egress IXC switch 150 in
message 140. In the case of screening, if the call is screened so that
completion is denied, the call need not be forwarded from the ingress IXC
140 to the egress IXC 150, but can be blocked in IXC 140 on the basis of
data returned in the response message.
FIG. 4 is a flow chart of actions performed in the ingress switch under the
control of program 119. The ANI number and the called number for a call
are received in the ingress switch (action block 202). This block is
performed as in the prior art. In addition, special billing information
such as a subaccount billing number may also be received along with the
call (action block 204). Subaccount billing procedures are described in
Bauer et al.: U.S. Pat. No. 4,776,004. Next, the ANI number is checked to
see whether it is associated with a fax machine (test 206), or a mixed use
line. If not, then routine call processing in accordance with the
principles of the prior art is performed for that call (action block 208).
If the ANI number is associated with a fax machine, then a fax flag, and,
alternatively, a preferred facilities routing flag, is inserted in the CCS
message to be sent to the next switch to which this call is to be routed.
Next, test 212 checks whether the store and forward indicator for that ANI
number is 1. If not, then the call is processed routinely from that point
with the exception of the retention of the fax flag in the CCS message
being generated (action block 214). If the store and forward indicator is
1, then a dual tone multifrequency (DTMF) receiver is attached to the call
(action block 216) and thereafter the call is processed routinely as
previously described with respect to action block 214. If subsequently
dialed DTMF digits are detected, representing a store and forward request
(action block 218), then the outgoing call from the ingress IXC switch is
disconnected (action block 220) and a connection to the customer selected
store and forward facility identified by the store and forward request
dialed by the customer is established (action block 222). The ingress IXC
switch then sends to the store and forward facility the ANI number, the
called number, and any special billing information generated in action
block 204 (action block 224). Thereafter, the call is processed as a
routine facsimile store and forward call wherein the CCS call set up
message includes a fax flag. It is, of course, necessary to make sure that
a S/F call is not terminated to another S/F system, since such a case
could lead to a large number of S/F message deliveries for one call
(action block 226). If the called terminal is busy, and message 172
including busy indicator 174 is detected (action block 240), then if the
calling fax number has automatic store and forward on busy (positive
result of test 242), the actions starting with action block 220 are
performed; if the result of test 242 is negative, the system continues to
wait for a customer dialed store and forward request.
If the ANI number is associated with a mixed use line, a DTMF receiver is
attached and the caller is prompted to key a 3 (for "F" ) for fax use or 8
(for "V" representing voice) for non-fax use (action block 230). If a 3 is
detected, indicating a fax call, then the actions previously described
starting with action block 210 are performed. If an 8 is detected,
indicating a non-fax call, then routine call processing as indicated in
action block 208 is performed. Any pair of different keys may be used to
indicate fax or non-fax.
There are a number of other methods for recognizing a fax call. A fax call
from an ISDN line can be recognized by the fax identifier in a signaling
message received at the ingress switch (action block 203). In response to
reception of a call with this identifier, the actions previously
described, starting at action block 210, are executed.
A call from a station 102 can also be recognized at the ingress switch as
being a fax call by a prefix such as a special alternative common carrier
code taken from those numbers of the series 10XXX which have not been used
to identify a common carrier and which have not otherwise been assigned or
a prefix code whose initial character is non-numeric such as # or #9
(action block 201). The special alternative common carrier code should
probably also specify a common carrier, since otherwise customers could
not specify an alternative common carrier on a fax message sent in
accordance with the principles of this invention. In response to reception
of a call with this special code, the actions previously described,
starting at action block 210, are performed.
Another alternative method of recognizing that a call is a fax call is the
following: Feature Group B and Feature Group D of Equal Access Signaling,
as described in the Bellcore document Notes on the BOC Intra-LATA
Networks- 1986, Technical Reference TR-NPL-000275, Issue 1, April 1986,
Section 6, provides for the transmission of two digits, called Information
Digits ("II" digits), between network switches to classify a call. II
digits have traditionally bee | | |
