Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND APPARATUS FOR LOCAL ROUTING OF TOLL FREE CALLS
RELATED APPLICATION
This application is related to, and hereby claims the priority benefit of and
incorporates by reference, related Application No. 09/249,395 entitled "Point-
of Presence
Call Center Management System", filed February 12, 1999, by Prem Uppaluru and
Mukesh
Sundaram, and assigned to the Assignee of the present invention.
FIELD OF THE INVENTION
The present invention relates to the field of telecommunication, and more
particularly to the management of toll free telephone calls.
BACKGROUND
Local telephone companies (so-called local exchange carriers or LECs) provide
users with local calling service within a service area known in the
telecommunications
industry as a Local Access Transport Area (LATA). When a user dials any number
within
his/her LATA, the LEC carries the call and charges the user at a specified
local rate.
Many of the calls a user makes to other numbers in his/her LATA are "free" or
subject only to a "local call" toll; that is, they are provided as part of the
user's basic
telephone service. These free calls are generally limited to calls within a
certain radius of
the user's phone. Calls dialed to numbers farther away, but still within the
user's LATA, are
known as "local toll calls" and like the "free" calls are carried by the
user's LEC. Such calls
are billed by the LEC at the prevailing local toll rate, which depends upon
the distance and
the time of day and are often subject to minimum one minute billing
increments.
Calls outside of a LATA are not handled exclusively by a user's LEC. Instead,
so-
called interexchange Garners (IECs) route these long distance calls between
LATAs and/or
LECs. Each long distance telephone call made by a user includes fees that the
IEC pays to
the originating and terminating LECs over whose facilities that call also
traveled. Those
fees, which are designed to recover the costs to LECs for use of their
facilities, are referred
to as access charges. Generally, access charges are applied for both incoming
and outgoing
calls. Thus, they tend to apply even for businesses that use toll free (e.g.,
800) service.
Under current government guidelines, these access charges are not incurred by
so-
called "enhanced services providers" (ESPs). In other words, although carriers
(such as long
distance telephone service providers) must pay local telephone companies for
the use of
their facilities, ESPs do not. So-called "enhanced" services are generally
defined as services
provided by telecommunications providers that involve subscriber interaction
with stored
data (i.e., database access), protocol conversion or a change in the form or
content of the
information sent or received by the caller. The tariff discrepancy comes about
because the
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2
Federal Communications Commission (FCC) classifies ESPs as "end users" rather
than
"carriers" for purposes of the access charge rules. Under current FCC rules,
ESPs are
considered end users when they purchase services from local telephone
companies. Thus,
ESPs pay the same rates as any other local phone service customer, and these
rates are set
separately in each state. By contrast, long-distance companies are considered
carriers, and
they pay interstate access charges regulated by the FCC. Examples of ESPs
include Internet
service providers (ISPs) and as recently as 1997, the FCC reaffirmed that the
existing rate
structure for ISPs should remain in place.
In the above-mentioned related application, a scheme for deploying local call
centers in an effort to minimize long distance toll charges for call center
service providers
was described. According to that scheme, toll free long distance calls to a
call center are
redirected to a local call center. The local call center is configured to
answer, service, queue
and route the call at a local point of presence close to the point of call
origination. The
local call center may thus provide initial processing of incoming calls;
holding and queuing
the calls until live operators at the physical call center are available. Once
the live operator
becomes available, the local call center routes the locally queued calls to
the physical call
center.
The benefit of using a local call center in accordance with the above-
described
scheme is that the call center service provider will only incur long distance
charges for the
time that the caller is actually connected to a physical call center operator.
Time spent in a
hold queue or answering automated menu questions, etc., will not add to the
long distance toll
charges, because that portion of the call is treated as a local call,
terminating at the local call
center. Nevertheless, it would reduce costs even further if the call center
service provider
were able to leverage the access charge exemption currently enjoyed by ESPs.
SUMMARY OF THE INVENTION
In one embodiment, a scheme for routing a call from a user location to a local
call
termination point is provided. In general, such routing is accomplished by
mapping a dialed toll
free number to a POTS-routable number within a local rate calling area (LRCA)
that includes the
user location. Enhanced services (for example, computer processing and/or
information access,
etc.) may take place at the local call termination point; and, subsequently,
the call may be routed
from the local call termination point to a remote call termination point by
mapping the POTS-
routable number to another number (e.g., a long distance number) associated
with a long distance
call termination point. In some cases, the local call termination point may be
a local call center
configured to answer, service, queue and/or route the call. Where protocol
conversion operations
take place at the local call termination point, the call may be transported
over a network
configured to use the Internet protocol (IP).
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It should be noted that the local call termination point may be located
outside of the
caller's LATA. Under current tarrif structures, where enhanced services are
provided such back
hauling of calls across a LATA boundary will not incur long distance toll
charges. Hence, in one
embodiment the present scheme takes advantage of this tarrif structure by
deploying local call
termination points only in selected LATAs and backhauling calls from other
LATAs to those
locations.
Mapping the dialed toll free number to a POTS-routable number generally
includes
determining an originating NPA-NXX for the user location, matching a routing
NPA-NXX for the
local call termination point associated therewith, and selecting a line number
for the local call
termination point according to routing NPA-NXX and the dialed toll free
number. In one
particular embodiment, the routing NPA-NXX is selected from a first table and
the line number is
selected from a second table. These tables may be stored as part of an SMS/800
service
management system database within a telephony network over which the scheme is
deployed.
In other cases, the tables may make up a portion of a database that includes
call routing
information to provide the above-described functionality. Such a database may
be stored, for
example, at one or more regional service control points within the telephony
network.
Thus, the present scheme provides for a telephony network configured to route
a
call to a dialed toll free number from a user location to a local call
termination point by
mapping an NPA-NXX of the user location to an NPA-NXX of the local call
termination
point and selecting a line number of the local call termination point using
the NPA-NXX of
the local call termination point and the dialed toll free number. Other
features and
advantages of the present scheme will be described further below.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and not limitation in
the
figures of the accompanying drawing in which like references indicate similar
elements and
in which:
Figure 1 illustrates portions of a conventional telephone network involved in
routing
a toll free call;
Figure 2 illustrates portions of a telephone network configured to route toll
free calls
in accordance with the methods of the present invention; and
Figure 3 illustrates one example of a local call center configured to perform
a
protocol conversion operation during the routing of a toll free call in
accordance with an
embodiment of the present invention.
DETAILED DESCRIPTION
Described herein is a scheme that allows for the identification of selected
toll free
numbers, conversion of these toll free numbers to POTS (plain old telephone
service)-
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4
routable numbers, and routing over local access trunks (e.g., to local call
centers) for
service. T'he scheme includes a call mapping process that interfaces with the
SMS/800
database service management system for toll free call routing. This mapping
enables
systematic specification of the called number and the carrier identification
code (CIC) fields
in the SMS/800 system so that each originating call may be directed over the
proper local
trunk for termination to the correct port at a local call center. This mapping
includes the
extraction of information from both the calling and called number to compose
the local
routing number.
The present scheme thus enables a number of distinct nationwide toll free
numbers
to be intercepted for local routing and processing at local call centers and
is described below
by way of various embodiments that include specific structures and methods.
Notwithstanding these particulars, however, it should be remembered that
alternative
embodiments that include alternative structures and methods may be employed
without
departing from the broader principles of the invention described herein.
Before describing the illustrated embodiments in detail, it may be helpful to
discuss
the overall operating environment in which the methods and apparatus of the
present
scheme may be deployed. The present scheme is particularly well suited for use
with toll
free service, which is a telecommunication service wherein subscribers are
assigned a number
(e.g., an 800 or 888 number, soon to be expanded to include other three-digit
codes) that
allows their customers to reach them without toll charges. American Telephone
&
Telegraph (AT&T) first introduced 800 "toll-free" service in 1967. At that
time AT&T
was the only IEC and all LECs automatically routed all 800 calls directly to
AT&T points
of presence (POP) without performing any translation from the dialed 800
number to the
true terminating number. In practice, the LECs screened incoming calls,
looking for a
characteristic set of first three digits (e.g., 800). Upon recognizing this
set of first three
digits, the LEC would hand over the call routing responsibilities to AT&T,
which would
decode the rest of the toll free number being dialed. This included performing
the number
translations and service area validation screenings. In this scheme, every
digit in the dialed
number had significance for screening and call routing. Thus, it was limited
in its
capabilities and required users to have separate 800 numbers for in-state and
out-of state
calls.
In 1981, AT&T introduced its common channel interoffice signaling (CCIS)
network and the network services system (NSS) database for providing its own
centralized
facility for 800 number translation and service provisioning. The system
required an LEC
to screen the first three digits of the dialed number (e.g., 800) and deliver
the area code for
the call's point of origin. AT&T's database would then determine whether the
call was from
an area for which the subscriber had purchased service and, if so, would
translate the called
number (800 XXX-XXXX) into a standard ten-digit number which could be routed
over
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AT&T's network. T'he use of CCIS and the NSS database enabled AT&T to offer
customized toll free numbers and other features that gave the service
subscriber some
control over how and where calls were routed through the network.
After divestiture, ATBcT retained the rights to its CCIS network and the NSS
database system. However, AT&T made provision for the regional Bell operating
companies (RBOCs) to lease database capacity to offer their own intra-LATA
toll free
service. The plan did not allow the RBOCs to use the NSS to provide exchange
access
services to other IECs.
In 1983 the federal courts allowed the RBOCs to implement a modified version
of a
pre-existing serving arrangement for an interim period until the RBOCs could
develop their
own 800 database system. This interim service was commonly referred to as the
"NXX
plan" and used the first six digits of the toll free number (e.g., 800 NXX) to
identify the
appropriate carrier. The North American Numbering Plan Administrator (NANPA)
assigned individual NXX codes to carriers that participated in this
arrangement.
A major limitation of the six-digit screening technique was that subscribers
had to
change toll free numbers in order to change service providers. This limitation
arose because
specific NXX codes were assigned to individual carriers. Changing carriers
thus entailed
added costs fog= subscribers, including new advertising, changes to
documentation and forms,
and potential loss of business due to customer familiarity with current toll
free numbers.
The six-digit screening arrangement also limited the selection of toll free
numbers that a
carrier could offer its customers.
In response to complaints regarding the six digit screening process by the
RBOCs,
the Federal Communications Commission (FCC) determined that a national
database system
for toll free access would offer both advantages and disadvantages as compared
with NXX
access. Such a system would enable toll free number portability and thus
facilitate
competition, since a customer could change carriers without changing numbers.
Although
the benefit of such a system was recognized, it was not until 1991 that the
FCC adopted a
comprehensive order that mandated the implementation of nationwide toll free
number
database access.
Under these and subsequent FCC rulings the management and assignment of toll
free
numbers transitioned from the interim 800 NXX plan to ten digit management in
a national
800 Service Management System (SMS/800) database. The SMS/800 is a computer
system
that provides an environment for entering call-processing data (e.g., routing
information)
regarding toll free numbers.
As shown in Figure 1, when a user 10 dials a toll free (e.g., an 800) number,
the call
is intercepted at a local service switching point (SSP) 12 so that a query can
be directed to
determine how the call should be routed. The SSP 12 obtains the routing
information from
a regional database known as a service control point (SCP) 14. There are ten
regional SCP
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databases in the United States, independently owned by some of the RBOCs and
the long
distance carriers. The SCPs each receive (periodically, e.g., every 1 S min.
or so) routing
information that has been entered in the SMS/800 system 16. Thus, upon
receiving a query
from an SSP, an SCP is able to return the carrier identification code (CIC) of
the carrier
that will transport the call to its destination number along with appropriate
routing
information. The routing information may be a translated "plain old telephone
service"
(POTS) number or the dialed toll free number and routing may be based on
special
considerations such as the time of day, day of the week, percentage
allocation, etc. Upon
receiving the CIC (a four digit numeric code that forms part of a larger
carrier access code
or CAC) and routing information, the SSP 12 either routes the call using the
LEC network
or hands the call to an IEC at the IEC's POP, based on whether a POTS number
or an 800
number is returned.
Against this backdrop refer now to Figure 2 and suppose a user 20 dials a toll
free
number to access a remote call center located in a distant LATA. Further
suppose that the
remote call center has arranged for the call to be routed to an appropriate
local call center
(LCC) in accordance with the methodologies described in the above-cited co-
pending
application. Initially, the call routes over the local loop to the serving
central office SSP
22 of the LEC. At SSP 22 the call is recognized as a toll free call and,
accordingly, the call
is suspended while a query for routing instructions is made to the regional
SCP 24. The SCP
24 gathers the associated carrier identification and routing instructions from
a local replica
of the SMS/800 system database and passes the information to SSP 22. The
routing
instructions returned to SSP 22 in accordance with the present scheme provide
that for each
designated called toll free number, the calling and called number will be
mapped to a
particular POTS-routable number and trunk assignment for a local call center
within the
user's local rate calling area. Along with these instructions, a special CIC
having a value of
"0110" is returned to SSP22. This CIC instructs the SSP22 to route the calls
over its own
network (i.e., that of the LEC). This ensures that the call remains on the LEC
network.
The manner in which these database routing instructions are determined is
described
below, where all phone numbers are of the form NPA-NXX-XXXX, with NPA being a
valid
area code, N being any digit between 2-9 and X being any digit between 0-9.
These numbers
are associated with local rate centers. The origination and termination NPA-
NXX
determine the toll charge for a call. Usually, one or more NPA-NXXs fall into
the same
rate center and calls between such numbers are considered local calls and are
referred to
below as Local Rate Calling Areas (LRCA). An LCC may service multiple LRCAs
through
proper choice of call termination NPA-NXXs from each LRCA.
Suppose the toll-free call originated in an LRCA with NPA-NXX as its
originating
prefix and suppose fiuther that the called toll-free number is 800-XXX-XXXX.
For each
LCC that services one or more LRCAs, two tables are constructed, one with two
columns
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and the other with three. In the first table (an example of which is shown in
Table 1
below), one column (e.g., the left hand column) is a list of all valid
originating NPA-NXXs
for all LRCAs serviced by the LCC. In the second column (e.g., the right hand
column) are
the associated NPA-NXX numbers for local routing purposes. In the second table
(an
example of which is shown in Table 2 below), the left-most column lists all
local routing
NPA-NXX numbers serviced by LCC (these values corresponds to those in the
second
column of the first table noted above). The middle column lists all the valid
called toll free
numbers handled by the LCC. Finally, the right-most column provides the
associated unique
XXXX line numbers for each toll free number.
The routing instructions for calls originating in this LRCA are constructed
from
these two tables as follows. First, for each toll free call, the originating
NPA-NXX is
looked up in the left-most column of the first table and the matching routing
NPA-NXX is
selected from the right-most column of the first table. Second, the routing
NPA-NXX and
the called toll free number together are looked up in the appropriate columns
of the second
table and the matching unique XXXX line number is selected from the right-most
column
thereof. Third, the NPA-NXX selected during the first step is combined with
the XXXX
line number selected during the second step to form the POTS-routable number
handled by
the LCC for the original toll free number in that LRCA.
Table 1 ~ Table 2
Column 1 Column 2 ~ Column 1 Column 2 Column 3
408223 408 660 408 660 800 999-70872400
408224 408 660 408 660 888 483-01012401
408225 408 660 408 660 877 663-34582402
408226 408 660 408 660 800 225-90002403
408227 408 660 408 660 800 543-18942404
408229 408 660 408 660 800 629-74132405
408238 408 660 408 660 888 358-12342406
408239 408 660 408 660 888 439-75642407
LRCA 408251 408 660 408 660 877 510-12892408
408252 408 660 408 660 888 555-12122409
408 253 408 660 415 651 800 999-70871980
408 256 408 660 415 651 888 483-01011981
408 257 408 660 415 651 877 663-34581982
408 258 408 660 415 651 800 225-90001983
408 268 408 660 415 651 800 543-18941984
LRCA
408 270 408 660 415 651 800 629-74131985
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415 415 651 888 358-12341986
211
415
651
415214 415 651 415 651 888 439-75641987
415225 415 651 415 651 877 510-12891988
415241 415 651 415 651 888 555-12121989
415 252 415 651 510 319 800 999-70878800
415 268 415 651 510 319 888 483-01018801
415 680 415 651 510 319 877 663-34588802
510 236 510 319 510 319 800 225-90008803
510 238 510 319 510 319 800 543-18948804
510 241 510 319 510 319 800 629-74138805
510 243 510 319 510 319 888 358-12348806
LRCA
510 245 510 319 510 319 888 439-75648807
510 255 510 319 510 319 877 510-12898808
510 257 510 319 510 319 888 555-12128809
510 261 510 319
510 730 510 319
As an example, consider a call originating at 408-223-1111 and suppose that
user
dials the toll-free number 800-999-7087, associated with a remote call center
(e.g., a
customer service call center for a business). The call is first intercepted at
the SSP
associated with the user's calling number and appropriate routing information
is requested.
The routing information provided is determined using Tables 1 and 2. From
Table 1, the
user's originating NPA-NXX (in this case 408-223) is determined to be in LRCA
1. This
NPA-NXX is mapped to a serving NPA-NXX for the local call center established
by the
business in that LRCA. In this case, the local call center is identified by
the NPA-NXX
408-660 (as is the case for all calls originating in LRCA 1).
Now, using the NPA-NXX of the local call center and the dialed toll free
number
(408-660 and 800-999-7087, respectively), a corresponding line number is
obtained from
Table 2. In this case, that line number is 2400. This line number extension is
combined
with the NPA-NXX of the local call center to produce the POTS-routable number
408-660-
2400. Thus, the dialed toll free number would be routed to 408-660-2400.
Similarly, a call
originating at 415-211-1234 (a number originating in LRCA 2) but dialing the
same toll-
free number, would be routed to 415-651-1980. The LCC that receives the call
on either of
the above numbers may treat the calls in the same fashion, as the routing
numbers are local
aliases to the toll-free number 800-999-7087.
In summary, the routing NPA-NXX is determined by the calling number NPA-NXX.
The called toll free number determines the routing XXXX line number. The
appropriate
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POTS-routable number (NPA-NXX-XXXX) and the special CIC (i.e., 0110) are each
assigned, so that the call may be routed over a local access trunk to an LEC's
local point of
interconnection (POI). The SMS/800 database is programmed according to the
above
instructions for each LRCA serviced by an LCC. In the remaining LRCAs (i.e.,
those that
are not serviced by an LCC), the SMS/800 database is programmed to route the
toll free call
without translation and with a CIC assigned to the desired IXC. This ensures
that in each
LRCA serviced by an LCC, the toll free calls are routed to it whereas in the
remaining
LRCAs, the calls are routed to the IXC network. Thus, any SMS/800 database
query
originated by a SSP is completed according to the routing instructions
described above and
call control returns to the serving central office. The call routes over local
access trunk
facilities extending from the serving central office to the LCC or routes to
the IXC network
if no such LCC exists for the LRCA.
At an LCC, each call may be processed by a computer telephony server as is
common in the call center industry. Such a server is able to receive the POTS-
routable
number to which the toll free number was mapped by the SMS/800 database. For
example,
using a table similar to Table 3 below, the LCC can determine which toll free
number was
called and process the call accordingly.
Table 3
Dialed Toll Mapping Local
Free # #
408 660-2400
800 999-7087 415 651-1980
510 319-8800
t t
t t
t t
Based on this unique number, the server may create instructions for
acceptance, call
control, and the corresponding voice response for that number (for example as
described in
the above-cited co-pending application). Note, a similar table (or at least
the information
contained therein) may be used within the SMS/800 system to provide mappings
between
dialed toll free numbers and local numbers (and vice versa).
The local routing of toll free calls described above enables several advanced
telecommunications applications to be deployed in a highly cost-effective
manner. One
such application is a nationwide enhanced toll free voice communications
service. This
service may be implemented using computer telephony servers at the LCCs, which
use the
POTS-routable number obtained by the local routing of a toll free number and
further maps
it to a matching POTS-routable long distance number or another matching toll
free number.
The server may optionally interact with the caller and then route the call to
the mapped
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number using the public switched telephony network (PSTN). The service can
also use the
POTS-routable number obtained by the local routing of a toll free number and
further map
it to a matching Internet Protocol network address and route the call to that
address over a
local network and/or the Internet transporting the voice information over
Internet
protocol (IP).
An example of this operation is shown in Figure 3. Here a local call center 30
includes two modules 32 and 34. The modules 32 and 34 may be servers or other
computer-
based components coupled through a network that utilizes IP to transport
information
between the modules. Note, in some cases, modules 32 and 34 may be
geographically
distributed such that they are not physically co-located. In such cases, the
two modules may
be coupled though a private wide area network andlor the Internet. In other
cases, the two
modules 32 and 34 may be physically close to one another, coupled through a
local area
network or other network that utilizes IP or another data transmission
protocol.
Regardless of how the modules are coupled in communication with one another,
their basic functionality remains the same. Module 32 receives voice
communications from
the user over the local access trunk facilities extending from the serving
central office as
discussed above. That is, module 32 is coupled to receive the user-initiated
call to the toll
free number through a port coupled to a line corresponding to the POTS-
routable number to
which that call was mapped. At module 32, that POTS-routable number is mapped
to an IP
address corresponding to module 34. Such mapping may be done using a look-up
table or
other mapping arrangement common in the voice-over-IP arts.
Having so mapped the POTS-routable number to an IP address, module 32 is now
able to transmit the voice data from the user to module 34 using IP. The voice-
to-IP
conversion may be performed using techniques common in the art. For example,
the voice
data may be sampled at an appropriate rate and the resulting digital
information may be
packetized according to the Internet protocol and transported accordingly
across
communication link 36 to module 34.
At module 34, the digital data may be reconstructed to voice data (if so
desired), and
the call mapped to a POTS (or even toll free) number associated with the
called business.
Such a mapping may be done using techniques common in the art, for example
using a look-
up table that associates the incoming IP address used by module 32 with an
outgoing POTS
number. Thus, the call from the user will have been first mapped to a local
POTS-routable
number to reach LCC 30, then mapped to an IP address for transport between
modules 32
and 34, then finally mapped to a POTS (or other) number for final connection
to the called
party (e.g., the remote call center).
An example of such mapping may make use of tables having the following
structures. Table 4 provides the structure for a mapping of a POTS number to
any of an IP
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address (e.g., to reach module 34), a long distance number (e.g., a customer
number) and/or a
proxy toll free number (e.g., of the distant call center.
Table 4
Local POTS IP Address Long distance 800 #
#
At module 34, a table having the structure of Table 5 may be used to map an IP
address to
any of a local POTS #, a long distance number or a proxy 800 number in a
similar fashion.
Table 5
IP Address Local POTS # Long distance # 800 #
Thus, such tables provide multiple translation mechanisms to complete and/or
facilitate the
required call routing.
By including an IP leg in the call in the above-described example, the call
center
provider qualifies for the enhanced services exception to the access charges
that would
otherwise apply to the long distance call between the LCC and the remote call
center. In
other words, the entire call from the user has now been'made truly "toll
free". Consider
that the call from the user first terminates at the LCC, within the user's
LRCA. Thus, this
portion of the call is subject only to local rates and not long distance
charges. Then,
because of the enhanced services being provided at the LCC (e.g., the protocol
conversion
operations discussed above or other enhanced services such as voice response,
computer
processing, database lookups, and/or information accessess, the call from the
LCC to the
remote call center is exempt from access charges under the current FCC
regulations. Thus,
both legs of the call are free from access charges, and the call center
service provider may
pass these savings along to its customers.
Thus a scheme for local routing of toll free calls has been described.
Although
discussed with reference to specific exemplary embodiments thereof, it should
be evident
that various modifications and changes may be made to these embodiments
without
departing from the broader spirit and scope of the invention as set forth in
the appended
claims. Accordingly, the specification and drawings are to be regarded in an
illustrative
rather than a restrictive sense.
