Note: Descriptions are shown in the official language in which they were submitted.
CA 02189588 2004-O1-21
DIRECTORY ASSISTANCE METHOD AND APPARATUS
Meld of the Invention
The present invention.relates to systems for
providing directory assistance services, and more
particularly relates to the provision of directory
assistance services to cellular telephone subscribers.
Background and Summary of the Invent
Telephone directory assistance services have
been available for. the past century. While improvements
have been made over the decades, such systems are still
poorly suited for use by subscribers of cellular
telephone services.
In prior art directory assistance services, a
customer dials an operator and identifies the name and
address of a party whose telephone number is desired.
The operator then locates the number, using printed
directories or a computer database, and provides the
number to the customer. (The provision of the number is
sometimes done by the live operator, but more typically
is done with a computerized voice response unit that
provides a synthesized voicing of the number.) After
the customer s inquiry has been satisfied, the
connection to the operator is terminated.
While satisfactory for most customers, this
arrangement is ill-suited for many cellular telephone
customers. For one, such customers are usually away
from their general work environments (e.g. in a
vehicle), and thus may not have ready access to a pencil
and paper in order to make a note of the desired number.
_ 2 _ ~ ~ 8 9 5 8 8 PATENT
(Even if such materials are available, the customer may
not find it convenient to interrupt other activities,
e.g. driving, in order to make a note.) In addition,
the process of initiating a second call -- to the
desired party -- entails further manual. operations (e. g.
hanging up, waiting for another dial tone, and dialing)
which may be a~hindrance to the customer's other
activities.
The present assignee, in the prior art, has
redressed..certain of these difficulties by providing a
directory assistance service that eliminates the need to
make a note of the desired number, or undertake a
redialing exercise. Instead, after determining the
telephone number desired by the customer, rather than
voicing it to the customer, the directory assistance
operator goes ahead and initiates a call to the desired
party, and connects the new outgoing call to the
original customer. (The operator may stay on the line
as a conferenced party so as to provide further
assistance, or may withdraw from the connection,
depending on the particular implementation.) This
arrangement obviates the need for the customer to make a
note of the voiced number, or to undertake a redialing
exercise. However, if the initiated call is not
completed (e.g. a "busy" tone is received), or if the
customer desires further directory assistance, then the
customer must again call the directory assistance
operator for help.
The problems associated With providing directory
assistance services to cellular customers are not
limited to hardships on the customers; the directory
assistance service and the cellular,carrier also
confront unique issues. In the assignee's prior art
system, for example, the cellular carrier (which is
typically responsible for billing of the customer) knows
.only that the customer has-dialed the directory
assistance operator, but does not know the number to
which the customer is ultimately connected by the
3 ~ ~ ~ y 5 ~ ~ PATENT
operator. Billing is thereby complicated. In the prior
art system, the toll charges (assuming toll calls are
permitted; often they are not) for the connection
between the customer and the desired number are simply
absorbed by the directory assistance service, and
recouped by billing the cellular carrier a sufficiently
large flat rate charge for each directory assistance
call so as to cover these costs. The cellular carrier
then bills the subscriber a fixed amount for each
directory.assistance inquiry, regardless of the toll
charges of any further connection established for the
customer by the directory assistance operator. This
arrangement, however, has a number of disadvantages. In
addition to increased cost, it also fails to provide the
cellular carrier useful information about its customers
calling patterns, which may affect decisions relating to
system expansion, etc.
In accordance with one preferred embodiment of _
the present invention, a directory assistance service is
provided which alleviates many of these drawbacks of the
prior art. For example, in one embodiment, a customer .
who wishes directory assistance services is connected in
the conventional manner to an operator who determines
the destination telephone number desired by the
customer. As in the prior art, the operator then
initiates a call connecting the customer to the
destination telephone number. However, rather than
dropping all further involvement with the call, this
embodiment of the present invention continually monitors
the connection thereby established for a predetermined
DTMF signal issued by the customer, such as that
obtained by pressing the "*" button or some other
button. If such a signal is detected, the customer is
transferred to a directory assistance operator, who can
then provide whatever further assistance 'is needed (e. g.
redialing a busy number, or providing further directory
assistance). By this arrangement, the press of a single
button~by the customer summons further directory
PATENT
assistance, rather than the redialing procedure required
by the prior art.
The preferred embodiment further addresses the
billing difficulties associated with completion of
customer calls by directory assistance operators.
According to this aspect of one preferred embodiment,
the directory assistance service logs, in a billing
database, information identifying the customer (i.e. the
customer identification number accompanying the call
from the cellular provider), the destination number to
which the~customer is connected, and the date, time and
duration of the customer/destination number connection.
This log of information is periodically provided to the
cellular carrier, allowing it to bill the customer for
the call connected by the directory assistance operator
and recoup the associated expense. This permits the
flat rate charged by the directory assistance provider
to be reduced correspondingly, and provides the cellular
service with more detailed information about its
customers usage requirements.
The foregoing and additional features and
advantages of the present invention will be more readily
apparent from the following detailed description, which
proceeds with reference to the accompanying drawings.
2 5 ,.
Brief Description of the Drawings
Fig. 1 is a block diagram depicting the hardware
used to implement one embodiment of the present
invention.
Fig. 2 is a flow chart depicting the process by
which directory assistance is provided to a customer in
accordance with the Fig. 1 embodiment.
Detailed Description
With reference to Fig. 1, a directory assistance
center 10 according to a preferred~embodiment of the
present invention includes.one or more T1 links l2 for
connection to customer networks, a private branch
. ~ ~ y J ~~ ~ PATENT
exchange (PBX) 14, and a channel bank i6 for coupling to
a plurality of operator telephones 18. Each operator is
further equipped with a terminal 20 that includes a
video display unit and a QWERTY keyboard with associated
5 dialing pad. The operator terminals are coupled to a
terminal server 22, which in turn is connected over a
data network 24 to a database server 26. The data
network further connects to a PBX host computer 28 and a
voice response unit (VRU) 30. The data network consists
of, but is.~not limited to, a Local Area Network (LAN)
supplemented by a number of point-to-point serial data
links.
The T1 links 12 provide connection between the
directory assistance center 10 and the cellular
carrier's switching center, through which incoming
directory assistance calls are received. The Tl links
12 further provide connection to the network over which
outgoing calls are placed (which network may be
different than that used for incoming traffic).
The PBX 14 is conventional, and its operation is
governed by instructions stored in the PBX host computer
28. These instructions simply implement the processes
hereafter described. In the preferred embodiment, the
PBX supports digital T1 telephone circuits, while in
other embodiments other PBXs can of course be used.
Included in the PBX is digital signal processing
circuitry which provides the requisite conference
capability (described below), and dual tone.multi
frequency (DTMF) and multi frequency (MF) tone
generation/detection capabilities.
Incoming calls received by the PBX l4 are
connected to an available operator via a T1 circuit 32
that is connected through the channel bank 16 to an
operator's telephone headset. If no operator is
available when a call is received, the call is a_ueued
until an operator becomes available. The queuing and
call distribution is standard Automatic~Call
Distribution (ACD).
s 2 ~ ~ y J g 8 PATENT
The terminal server 22 simply serves as an
interface between serial devices, such as the operator
terminals 20, and the data network 24, allowing the
terminals to login as devices on the network.
The database server 26 provides operators with
the means,to search for a customer's desired party, and
determine the appropriate telephone number. In the
preferred embodiment, the database provides the
capability to search not just by name and address, but
also by type of goods/services and/or geographical
region. (E. g. the preferred database can answer queries
soliciting the names/numbers of shops carrying model
rocketry supplies in southeast Portland, Oregon, or of
Chinese restaurants on a given street.) Data indexed in
this fashion is usually not commercially available, so
the present assignee starts with a commercially
available database file (e. g. the Directory Assistance
Database Source available from U.S. West), and enriches
it by adding further data manually..
Desirably, the results of the database search
presented on the operator's terminal 20 are not
alphabetized prior to display, but rather are presented
in the order located by the database search engine. (If
.desired, a deliberate randomization of order could be
effected before display). Businesses at the beginning
of the alphabet are thereby not unduly favored by
customers using the directory assistance service.
The~database software itself is conventional.
The presently preferred best mode us to use a relational
database, such as is available from Sybase. However,
much simpler software can alternatively be used, such as
_ DBase 4.
The voice response unit (VRU) 30 is incorporated
into the system to play the constantly repeated parts of
an operator's speech, namely the various greetings and
signoffs (or closings). Nflt only does this system
provide a voice-saving and monotony-relief function for
the operators, it performs a 'branding' function (i.e.
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the pre-recorded messages incorporate the name of the
telephone company through which the customer was routed
to the directory assistance service), and it also
reduces the amount of time an operator is actually
connected to a customer.
The VRU 30 is connected via the data link 24 to
the PBX host 28 (to which it acts as a slave processor)
and via one or more T1 spans to the PBX 14 itself. More
than one VRU can exist in a system. At appropriate
stages in a call progression, the PBX host 28 initiates
a voice path connection between the VRU and the PBX such'
that the caller, or the caller and the operator, are
able to hear whatever pre-recorded speech is played on
that circuit by the VRU. It~then instructs the VRU, via
the data network, what type of message to play, passing
data parameters that enable the VRU to locate the
message appropriate to the call state, the service-
providing telephone company, and the operator. The
recording density used is. high enough to provide a good
enough quality of message playback that most users of
the system should be unaware they are listening to a
recording.
Method of Operation
. Customers of a particular telephone company
simply dial the access digits established for directory
assistance by that company. Examples of typical access
digits are "*555" and "555-1212."
The participating telephone company~s own
switching systeia will then reroute the call to the
directory assistance service center 10 (via a Tl
channel), where it appears as an incoming call.
Automatic Call Distribution~(ACD) logic is used
to queue (if necessary) and distribute calls to
operators in the order in which they are received, and
such that the call traffic; is distributed evenly among
the operators.
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When a call is connected to an operator,.the VRU
30 (also conferenced into the call) plays a greeting
message, using~a message pre-recorded by the connected
operator. Both the operator and the calling customer
hear the message, which incorporates the name of the
service or company to which the customer is a subscriber
(in other words, the call_is "branded"). The message
ends with a prompt, thus cuing the customer to volunteer
what information they are seeking.
When the automated greeting is complete, the VRU
is disconnected, and the operator and the customer are
left connected by a 2-way speech path. From this point,
the caller is interacting with a live operator.
In the event that the VRU is non-functional (for
whatever reason), the incoming call is connected to the
operator and a short "trill," or "zip" tone is played to
indicate that a caller is on the line. (Note that once
operators are logged in to the system, they wear
headsets, and have their .telephones l8 permanently off-
hook. Their telephones do not,ring when a call is
presented). The operator then speaks a greeting and
prompt in real time, instead of the VRU playing a
message.
If the caller requests information concerning,
for example, local theater performances, the operator
speaks a response based on hard copy information. At
this point, the caller will be released from the call,
and the operator becomes available to handle further
calls.
If the caller is seeking directory assistance,
the operator will engage in live dialogue to establish
the name and other pertinent information of the wanted
party, and then initiate a database search using the
operator terminal 20 and associated database server 26.
In the event of an unsuccessful search, the operator
will use alternative sources, such as the Electronic
White Pages (EWP) or even printed directories.
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The operator can connect the caller to the
wanted party~s number using one of two possible methods
of call transfer: Blind Transfer or Hotline Transfer.
In either case, the call transfer is invoked by
sending a sequence of digits (that includes the wanted
party~s number) to the PBX host 28. The conventional
method of doing this is simply dialing the digits on the
operator s telephone handset (having first depressed the
"flash" key to obtain dial tone). This method is always
available. A much quicker and more accurate call
completion method is generally preferred: the operator
highlights the desired database entry on the screen of
the terminal 20, and then initiates Blind or Hotline
transfer to that number by entering a few keystrokes on
the terminal keyboard. In this case, the database
server 26 transmits the same digit sequence as part of a
message to the PBX host 28, via the network 24.
More specifically, in the preferred automated
call completion method, the operator locates the desired
listing in the database, and presses the "enter" key at
the operator terminal 20 to select the listing.
Whereupon, the operator terminal 20 displays a main call
completion menu along with a selected listing. One
example of such a menu is as follows:
Main Call Completion Menu
1) Connect with Transfer back
2) Connect with NO Transfer back-
3) Conference connect with Transfer back
4) Conference connect with NO Transfer back.
5) Supervisor
6) Manual Dial
7) No connect
Options (1) and,(2) of the main call completion
menu initiate the "Blind Transfer" to the selected
listing as described more fully below. Options (3) and
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(4) initiate the "Hotline. Transfer" described more fully
below. Option (5) is selected by the operator to summon
the operator's supervisor for assistance handling the
call. Option (6) overides automated dialing of the
selected listing, and allows the operator to manually
dial a number at the operator terminal 20. Option (7)
cancels call completion.
When the operator selects option (6), the
operator terminal 20 displays a call completion sub-menu
such as follows:
Manual Dial Call Completion Sub-Menu
Enter telephone number .
1) Connect with Transfer back
2) Connect with NO Transfer back
3) Conference connect with Transfer back
4) Conference. connect with NO Transfer back
5) Supervisor .
6) Change~Number
~) No connect
Upon selection of any'of the connection options.
(1) - (4) of either the main call completion~menu or
manual dial call completion submenu, the database server
26 sends a data packet to the PBX host 28, via the
network 24. The data packet contains the appropriate
station ID and the digit sequence of the selected
listing or manually entered telephone number in the case
of option (6). The PBX host 28 creates a conference
bridge with the caller and the called party, then either
completes the "Blind Transfer" in the case of options
(1) or (2) or continues with the "Hotline Transfer" in
the case of options (3) or (4). In the case of options
(1) or (3), the tone triggered return transfer operation
. which is described more fully below is enabled during
the call. In the case of-options (2) or (4), the tone
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triggered return transfer or transfer back operation is
disabled as also discussed more fully below.
"Blind Transfer" is the normal means by which an
operator establishes a connection between the caller and
the wanted party's number. As soon as the PBX host 28
receives the Blind Transfer command (whether from the
database server 26 or the operator's telephone set_18),
an attempt is made to establish a route out of the PBX
14. If successful, the circuit is seized and the
address digits propagated, using the protocol the
circuit is configured for: the operator is released
from the call and made available to receive further
calls. If the VRU 30 is operational, it is commanded to
play a signoff message (pre-recorded by the just-
released operator). If the VRU is not available, the
operator speaks the signoff message before initiating
the transfer. The VRU status is known by whether the
call was initiated by a VRU-played greeting, or by zip
tone. Failed routing attempts cause reorder tones to be
returned to the operator's handset, or an error
indication to be returned to the database server 26
(depending on how the PBX host received the transfer ..
command).
Like Blind Transfer, the "Hotline Transfer"
method of establishing a connection between the caller
and the wanted party's number can be initiated by the
operator from either the telephone handset 18 or from
the data terminal keyboard 20. The difference is that
the operator is not automatically released from the call
in a Hotline Transfer. Instead, he/she is conferenced
into the call by the PBX 28 and is able to monitor its
progress. Using either the telephone handset or the
data terminal keyboard, the operator may withdraw from
the call after verifying its establishment, or may cause
the called circuit to be released.and then re-engage in
dialogue with the caller.
Hotline Transfers--are used when a caller
requests that the operator "stay on the line."
12 2 ~ ~ C~ J ~ ~ PATENT
If, after initiation of a transfer (whether or
not it succeeds), and at any time before the caller
hangs up, the caller requires further operator
assistance, the caller can perform a tone signal
triggered, return transfer back to. an operator
.(hereafter referred to as "tone triggered return
transfer" or "transfer back"). This is.done simply by
pressing the "*" (star) key or another designated~key on
the caller's telephone once or twice (depending on the
system, and as instructed by the operator in the signoff
message).
The star or other designated key tones) is
detected by a DTMF receiver (allocated in the PBX 14 for
the entire duration of the call), and causes the caller
to appear as a fresh call to the ACD logic. This in
turn results in the caller being connectedlto an
available operator, whereupon the PBX host 28 instructs
the connected VRU 30, to play the appropriate pre-
recorded signoff message with return transfer
instructions. Note that the operator to whom the call
is connected is allocated according to the ACD
algorithm, and may or may not be the same operator that
previously handled this call. From this point, the call
is treated in the same way as a non-tone triggered
return transfer call.
The "tone triggered return transfer" feature
enables callers who have been transferred by means of a
Blind Transfer to recall an operator if the transfer
does not complete satisfactorily (for example, receipt
of reorder tone, busy tone, operator intercept tri-
tones, ring-no-answer, silence, or wrong number). It
also enables a caller to request a follow-on call at the
completion of a successfully completed call without
incurring the delay or difficulty of re-dialing into the
system.
It will be recognised that, in the preferred
embodiment, the desired number is not voiced to the
customer unless explicitly requested. Sometimes a
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customer uses the "tone triggered return transfer"
feature to request that the number be voiced if, for
example, he or she finds a follow-up call is necessary
later.
A flow diagram illustrating the sequence of ..
events in a directory assistance system employing the
present "tone triggered return transfer" technique is
provided in Fig. 2.
The "tone triggered return transfer" technique
enables the cost-effective provision of many services .r
not previously available. For example, a directory
assistance center~may offer mapping/locator services
which provide spoken directions to guide vehicle-based
customers from their present location to a desired
destination. However, to obviate the need for the
customer to write the directions down while in the
vehicle,~the operator should be available to issue
instructions along the course of the vehicles route.
By using the "tone triggered return transfer" or
"transfer back" feature, the customer can receive
initial instructions, and thereafter summon further
instructions as needed along the route simply by
pressing the star or other designated key. In such a
system, the customer s connection to the directory
assistance center is maintained during the course of the
trip, but the operator can attend to other customers
while the travelling customer doesn't need the
operator s immediate attention. (Since "tone triggered
return transfer" may return the customer to a different
operator, provision is made for transferring -- with the
customer -- a pointer to the particular database record
~i.e. map or directions) being utilized by that
customer, wand a pointer to a current location within
that record. By this, arrangement, a different operator
who is summoned for assistance using the !'tone triggered
return transfer" feature can pick up.where the last
operator left off.) While driving between operator
- 14 - ~ '~ ~ ~ PATENT
instructions, the customer is simply kept in a "hold"
state.
Sometimes the customer will be connected to a
destination telephone number that makes its own use of
"*" or othere designated key tone. For example, some
automated order entry systems require the caller to
press the "*" key to signal the end of an entry, etc.
Others require the caller to press the "*" key to access
certain information.
To accommodate such possibilities, the preferred
embodiment of the present invention stores data in
database 26 to indicate which destination numbers make
their own use of the "*" key or other transfer back
feature. designated key or key series. If the customer
is connected~to such a destination telephone, then the
"tone triggered return transfer" feature is disabled.
If the user presses the "*" key while connected to such
a destination number, it is ignored by directory
assistance center 10. But when the customer thereafter
calls another destination telephone number that is not
so listed in the database, the "tone triggered return
transfer" feature is once again available.
Sometimes database 26 may not contain complete
information identifying destination numbers that make
their own use of the "*" key. Moreover,, some directory
assistance systems may not track this data at all. ~ In
such circumstances, the directory assistance center 10
desirably includes provision to manually disable the
"tone triggered return transfer" tone detector. This
disabling can be done by operating a switch at the
operator's console, by entering a command on the
operator's keyboard, or by activating an icon on the
operator's tenainal 20.
Such a manual disabling of the "tone triggered
return transfer" tone detector can occur, for example,
when a caller is inadvertently transferred back to the
operator by using the "*" ~cey to access a service at the
destination number. The caller can note- the problem to
15 ~ ~ ~ ~ PATENT
the operator, who can disable the feature and reconnect
the caller to the destination number. In other
situations, the caller may know in advance that the
destination number makes use of the "*" key (e.g. for
electronic banking),. and can request that the operator
disable the "tone triggered return transfer" tone.
detector before the connection is first made.
Billing issues
Although these can be varied, there are three
billing components of a typically cellular-phone
originated call to a directory assistance service
according to the present invention:
1) "Air time," or the total time the caller
uses the cellular carrier s cellular radio system to
carry a call from his/her cellular telephone. This is
the responsibility of the cellular carrier.
2) The per-call charge levied for_ use of the
directory assistance service. This charge is made by
the directory assistance service to the cellular carrier
on the basis of the number of calls received from the
carrier in a particular time period.
3) Toll charge - the charge levied by a
carrier for the duration of an answered connection over
a toll route originated by a directory assistance
operator. This charge is levied by the carrier used for
completion of customer calls originated by the directory
. assistance operator. The cellular carrier is dependent
on the directory assistance service to provide enough
details of these calls to enable it to accurately bill
its subscribers accordingly. There are two ways of
doing this:
1) The directory assistance service provides
"tickets" of all calls that were transferred and
answered. The precise content and format of the ticket
is customer-defined, but includes at least the following
information: calling number, called number, date and
time of connection (i.e. when answer indication was
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received), and duration of call. The ticket files can
be transferred on magnetic tape or by means of
electronic file transfer.
2) The digits that are dialed by the directory
assistance service's PBX to initiate the call transfer
(via the cellular carrier's network) can incorporate the
calling party number ("A" Number Identification, or
ANI). The cellular carrier's own switching equipment
then has all the information needed to generate the
l0 required tickets.
It is the cellular carrier's responsibility to
rate the calls and determine what charge is to be
levied.
Having described the principles of our invention
with reference to a preferred embodiment and certain
variations thereon, it should be apparent that these
examples can be modified in arrangement and detail
without departing from such principles.. For example,
while the invention has been illustrated with reference
to a system iri which a "tone triggered return transfer"
customer is routed back to the next available operator,.
in other embodiments, provision can be made for routing
the customer back to the original operator. (In some
systems, the customer can be given a choice: pressing
one key for the first available operatox, and another
key to be inserted in the original operator's queue.)
In view of the many possible embodiments to
which the principles of our invention may be put, it
should be recognized that the detailed embodiments are
illustrative only and should not be taken as limiting
the scope of our_invention. Rather, we claim as our
invention all such embodiments as may come within the
scope and spirit of the following claims and equivalents
thereto.
