Method and system for extending the directory number of a terminal

A method and system are disclosed for extending the directory number of a terminal. The invention allows service providers to provide a service which uses an existing subscriber directory number and effectively extends it to include one or more other directory numbers. To the subscriber, the terminals associated with the other directory numbers effectively look like virtual extensions. The method and system provide this flexibility without requiring any additional personal numbers being assigned to the subscriber. The subscriber can choose to have all incoming calls to a directory number (DN) of one of their existing terminals alert or ring one or more other terminals having a different DN. The terminals may for example be on the same network (e.g. all on the wireline network) or they may be on different networks (e.g. one on the wireline network and one on the wireless network). The method and system are substantially transparent to subscribers and calling parties as no additional numbers or new DNs of any sort are required.

FIELD OF THE INVENTION 
This invention generally relates to telephony services and more 
particularly to a method and system for extending a directory number of 
one terminal to include one or more terminals each of which has a 
different directory number. 
BACKGROUND OF THE INVENTION 
As competition intensifies between service providers of telephony services, 
providers are looking for services which provide great value and 
flexibility for their subscribers. Services which increase the likelihood 
of a calling party reaching the person to whom they wish to contact can 
provide subscribers with increased flexibility and can increase service 
provider revenues. 
Some service providers today offer flexibility by providing their 
subscribers with a 1-500 service. The service allows a subscriber to 
inform a respective service provider which terminals, each of which has a 
unique directory number (DN), the subscriber wishes to be alerted 
simultaneously in response to an incoming call to the subscriber's 1-500 
number. A directory number is a number which has a direct association with 
a line appearance on a physical switch and to which a physical terminal is 
associated. Switch translations are capable of directly translating a DN 
into a line port or line appearance on a switch within a Wireline or 
wireless network. 
In the event of an incoming call to the special 1-500 number, the service 
provider's network will correspondingly alert those terminals 
corresponding to DNs provided by the subscriber and contained in a 
customer lookup table or profile. The alerted terminal which first 
responds by going off hook for example is connected to the calling party 
associated with the incoming call. Incoming calls however, to any of the 
individual DNs contained in the lookup table or profile rather than the 
special 1-500 number will however only be routed by the network to the 
individual terminal corresponding to that DN. Callers who wish to contact 
a subscriber to the 1-500 service may not be able to if they are unaware 
of the 1-500 number and the subscriber happens not to be in the physical 
location corresponding to the individual terminal being called. The 1-500 
service is hardly transparent to the subscriber as it requires a separate 
and additional number. 
Other service providers provide their subscribers with substantially the 
same service by providing a new separate personal telephone number and 
associate a customer profile to that personal number. The customer profile 
is used by the service provider's network to assist in the routing of an 
incoming call to the subscriber's personal number. A caller who is aware 
of the `personal number` can attempt to reach the subscriber by dialing 
their personal telephone number and in much the same way as for the 1-500 
service an incoming call to the personal number will be routed according 
to the subscribers profile to one or more of the subscribers terminals, 
each of which would have their own DN. The shortfalls of this method are 
substantially the same as for the 1-500 service. Numbers such as the 
`1-500` and the `personal number` described herein are not considered to 
be directory numbers as defined in this specification. 
As the new generation of Personal Communications System (PCS) networks are 
deployed over the next few years, a key requirement for the operators of 
these networks will be offering services that provide the greatest 
possible flexibility. A major opportunity in this area for example for 
current wireline and wireless service providers is to provide ways to 
integrate their respective networks while keeping the integration 
substantially transparent to subscribers of either network. Of particular 
interest to service providers in general is to be able to provide a 
service to their subscribers that would allow them to extend a directory 
number of one terminal to include other terminals having different 
directory numbers. To the subscriber the service effectively allows them 
to create one or more virtual extensions to an existing directory 
number(DN), where each of the virtual extensions or extended DNs have 
their own unique network DN. Some of the challenges facing the service 
providers are how to best implement the service from a cost perspective; 
how to provide the service such that it is transparent to the subscriber; 
and how to implement the service such that it is also capable of allowing 
subscribers to extend a DN associated with one network (wireline or 
wireless) to include a DN on the other network. 
SUMMARY OF THE INVENTION 
The invention seeks to provide an improved method and system for extending 
a directory number of one terminal to include another terminal having a 
different directory number. 
According to one aspect of the invention there is provided a method of 
extending a subscriber directory number to one or more terminals each of 
which have different network directory numbers, comprising the steps of: 
a) in response to an incoming call from a calling party to the subscriber 
directory number associated with a switch, flagging at said switch that 
the incoming call to the subscriber directory number requires special 
treatment and temporarily suspending regular call processing; b) 
determining that the subscriber DN is one which is to be extended to 
include one or more terminals, each having different network directory 
numbers; c) determining the DN of all terminals the subscriber DN is to be 
extended to; and d) initiating call setups to the subscriber directory 
number and to each DN determined in step `C` and alerting the terminal 
associated with the subscriber DN along with the terminals associated with 
the DN's determined in step `C`. 
According to a further aspect of the invention there is provided a method 
of extending a subscriber directory number to one or more terminals each 
of which have different network directory numbers, comprising the steps 
of: a) in response to an incoming call from a calling party to the 
subscriber directory number associated with a switch, flagging at said 
switch that the incoming call to the subscriber directory number requires 
special treatment; b) determining that the subscriber DN is one which is 
to be extended to include one or more terminals, each having different 
network directory numbers; c) determining the DN of all terminals the 
subscriber DN is to be extended to; and d) initiating call set ups to the 
subscriber directory number and to each DN determined in step `C`. 
According to yet a futher aspect of the invention there is provided a 
system for extending a subscriber directory number to one or more 
terminals each of which have different network directory numbers 
comprising ; means for flagging at a switch that an incoming call to the 
subscriber directory number requires special treatment and temporarily 
suspending regular call processing of the incoming call; means for 
determining that the subscriber DN is one which is to be extended to 
include one or more terminals, each having different network directory 
numbers; means for determining the DN of all terminals the subscriber DN 
is to be extended to; and means for initiating substantially 
simultaneously call set ups to the subscriber directory number and to each 
DN determined in `C`. 
The invention allows service providers to provide a service which uses an 
existing subscriber directory number and effectively extends it to include 
one or more other directory numbers. To the subscriber, the terminals 
associated with the other directory numbers effectively look like virtual 
extensions. The method and system provide this flexibility without 
requiring any additional personal numbers being assigned to the 
subscriber. To a subscriber of such a service the benefits are significant 
in that the subscriber can choose to have all incoming calls to a DN of 
one of their existing terminals alert or ring one or more other terminals 
having a different DN. The terminals may for example be on the same 
network (e.g. all on the wireline network) or they may be on different 
networks (e.g. one on the wireline network and one on the wireless 
network). The method and service are substantially transparent to 
subscribers and calling parties as no additional numbers or new DN's of 
any sort are required. 
The active subscriber who never wants to miss a call from a business 
customer or their stock broker for example, can regardless of where they 
are stay in touch and be reached all without the calling party being 
required to dial a special additional number. If for example a business 
terminal DN is the number to which the service is provisioned against then 
any incoming calls to that DN can also alert a residence terminal. In a 
preferred embodiment, both the business as well as the residence terminal 
may be alerted substantially simultaneously and which ever terminal 
responds to the alerting condition first by going off hook, gets connected 
to the incoming call. 
The method and system allow a wireline carrier or service provider to 
transparently provide an integrated service with wireless or cellular 
mobility. For wireless or cellular service providers, it allows for the 
opportunity to integrate their wireless service offering with a 
subscriber's existing wired residence or business service.

DETAILED DESCRIPTION 
The Intelligent Network (IN) architecture has been evolved through the 
efforts of various groups, in particular Bellcore, European 
Telecommunications Standards Institute (ETSI), International 
Telecommunications Union (ITU-T), and American National standards 
Institute (ANSI). These groups have issued respective documentation 
defining the general Intelligent Network architecture along with the 
various entities found within the Network. Advanced Intelligent Network 
(AIN) is another industry term for the Intelligent Network (IN). 
Generally known telecommunication intelligent network entities in existence 
today along with other terms used in the detailed description are briefly 
described in general terms below: 
SSP--(Service Switching Point) That node in an Intelligent Network normally 
associated with an end office and equipped with Advanced Intelligent 
Network (AIN) software. A SSP is generally a central office enhanced with 
CCS7 messaging links and AIN software which permit it to communicate with 
application data bases such as Service Control Points (SCP's). Pre-defined 
Call Processing Triggers in the SSP AIN software result in the SSP 
initiating queries to network SCP's for information regarding completing 
call processing of a particular call. 
STP--(Signal Transfer Point) A packet switch in the Common Channel 
Signaling No. 7 (CCS7) Network that enables cost effective routing of CCS7 
signals between other network elements (CCS7 nodes). 
SCP--(Service Control Point) A centralized network element in the 
Intelligent Network that individual switches call upon to obtain 
information and commands necessary for completing an AIN call. The SCP is 
the intelligence center in an CCS7 AIN network which processes queries for 
information and returns a response to the originator of the query. 
SN--(Service Node) A Service Node is a network node that provides service 
circuits and generally supports Call Processing type services as well as 
Operation, Administration & Maintenance type (OA&M) services. For example 
a SN can provide phone type services such as Advanced Messaging Services, 
Automatic Call Distribution and Customized Announcements. Service Nodes 
may also provide OA&M support for SN based services such as customized 
billing reports, service usage reports and Subscriber changeable service 
parameters. 
IN--(Intelligent Network) A generic term for the Advanced Intelligent 
Network. 
IP--(Intelligent Peripheral) An Advanced Intelligent Networking Network 
Element that generally only controls a special set of features or provides 
a specialized set of functions to support features. Intelligent 
Peripherals are similar to SCP's in that they provide the intelligence to 
drive AIN features but are more specialized. 
MTSO--(Mobile Telephone Switching Office) The location of a switch which 
controls the operation of a cellular or wireless system. The MTSO, also 
known as a Mobile Switching Center (MSC) is a cellular switch and is the 
network entity that provides the actual call capability to a mobile or 
cellular terminal. 
HLR--(Home Location Register) The entity in a cellular network in which a 
mobile subscriber's main database entry resides. Information in the HLR 
generally includes the subscribers profile and where the subscriber's 
mobile terminal is currently located. 
VLR--(Visiting Location Register) The entity in a cellular network 
generally co-located with a MTSO and is used by the cellular network to 
update a subscriber's HLR with the whereabouts of the subscriber's mobile 
terminal and is also involved in call delivery to the mobile terminal. 
In existence today are wireless networks and wireline networks, each of 
which are very often owned and operated by different service providers 
(SP's). 
Wireline terminals today have individual directory numbers and are directly 
linked to switching offices within the wireline network. Wireless or 
cellular terminals, even though allowed to roam still have individual 
directory numbers which are directly linked to the terminal's Home Mobile 
Switching Center (Home MSC), i.e. the MSC in the cellular or Wireless 
Network to which the public switched telephone network (PSTN) routes the 
cellular terminals calls. Incoming calls on the wireline network and 
destined for a wireless terminal are switched or routed to the wireless 
network. In a similar manner incoming calls on the wireless network and 
destined for a wireline terminal are routed to the wireline network for 
delivery to the wireline terminal. 
In a preferred embodiment, various end office, AIN software equipped 
switches referred to as Service Switching Points 12, (SSP) of a typical 
Wireline network 10 are shown in FIG. 1 interconnected over interoffice 
trucks 14. It is to be understood that all wireline terminal directory 
numbers in this description terminate on an SSP 12 within the wireline 
network 10. A wireless network 20 having multiple Mobile Switching Centers 
(MSC) 22, each having an integral Visiting Location Register database 
(VLR) are interconnected in conventional manner over interoffice trucks 
(not shown). A centralized Home Location Register (HLR) database 26 is 
connected over data links 28 to each of the MSC's and is thus capable of 
being accessed by each MSC 22 in the wireless network 20. All wireless 
terminal directory numbers in this description terminate on a MSC 22 
within the wireless network 20. The wireless network 20 is connected to 
the wireline network 10 over for example a Feature Group D trunk which 
interconnects one MSC 22 of the wireless network 20 with one SSP 12 of the 
wireline Network 10. 
AIN Network elements in the preferred embodiment which assist in providing 
the functionality to extend a DN and to integrate the two Networks 10, 20 
are provided by a Service Control Point (SCP) 24 and a Service Node or 
adjunct processor 42. The SCP 24 in this embodiment is centralized and 
accessed by individual SSPs 12 over BellCore defined AIN 0.1 signaling 
links. The Service Node 42 in FIG. 1 is shown centralized but may be 
distributed (i.e. one SN per switch). The SN 42 is connected to each SSP 
12 over a separate Feature Group D trunk 34 (for clarity only one 
connection is actually shown). 
FIG. 2 illustrates a general call flow associated with the system of FIG. 1 
for a basic incoming call to a DN of a terminal on a wireline network and 
the simultaneous alerting (ringing) of the wireline terminal and one 
cellular terminal. Also in this call flow the wireline terminal goes off 
hook or answers before the wireless terminal and is thus connected to the 
calling party originating the incoming call. More detailed call flows 
showing specific messaging and respective parameters will follow. 
Network elements shown along the top of all call flows will carry the same 
numeric designation to identical network elements shown in FIG. 1. Within 
current day signaling networks Signal Transfer Points (STP) 40 (FIG. 2) 
may be found between SSPs and SCPs and this interface is shown as a dotted 
line in the call flow of FIG. 2 and subsequent call flows. In this 
particular call flow the subscriber of the wireline terminal (residence or 
business) subscribes to an Extended Directory Number service in accordance 
with an embodiment of the present invention and hence the wireline DN will 
become the DN to which this service is associated with or anchored to and 
will be referred to as the Extended Directory Number (Ext-DN). The 
Extended Directory service will therefore key off of any incoming call to 
the Ext-DN. It is expected that the subscriber associated with the Ext-DN 
will be billed accordingly for the service by their respective Service 
Provider (SP). 
In operation, the wireline subscriber wishing to subscribe to the Extended 
DN service would notify their respective service provider. The service 
provider then is provided with the directory number(s) of those additional 
terminals which the subscriber wishes to be alerted simultaneously with 
the subscriber's existing wireline terminal, now identified as being the 
Ext-DN. These additional terminals may be for example, pagers, wireless or 
other wireline terminals or combinations thereof. In the call flow of FIG. 
2, once the subscriber subscribes to the service the DN of their existing 
wireline terminal becomes the Ext-DN and the terms CallEd DN of an 
incoming call and Ext-DN become essentially interchangeable as both terms 
refer to the same physical terminal. The service provider of the Ext-DN 
then provisions or datafills the respective SSP 12 to identify the 
subscriber wireline DN as subscribing to the Extended DN Service. Any 
incoming calls to the Ext-DN would be flagged as requiring special 
treatment. This is achieved in the preferred embodiment within a current 
AIN 0.1 equipped SSP 12 by provisioning a `Termination Attempt` (TAT) 
trigger detection point (TDP) against the Ext-DN, as will be described. 
Referring now to the call flow of FIG. 2, point `A` in the call flow 
indicates a calling party initiating a call to the wireline DN which in 
actual fact has been provisioned by the SP of SSP 12 to be the Ext-DN. The 
incoming call has been routed to the respective SSP 12 at point `B` in the 
call flow. As a result of the TAT trigger detection point being 
provisioned against the Ext-DN the SSP 12 temporarily suspends call 
processing of the incoming call at the point in the call processing where 
the a `termination attempt` to the Ext-DN is normally made (i.e. before 
alerting or call connection is made to the Ext-DN). With respect to this 
particular incoming call this is the first `termination attempt` to the 
Ext-DN. The SSP 12 sends (`B`) a switch event message, in this particular 
case a `termination attempt` message to the SCP 24 to request how to 
continue with the call processing of this incoming call (C1). The SCP 24 
after looking up the user profile associated with the Ext-DN (the CallEd 
DN) determines that the DN is one which is associated with the Extended DN 
service and returns (C2) an AIN `forward Call` message to the SSP 12 with 
routing instructions to forward the call to Service Node 42. At point `D` 
in the call flow the SSP 12 complies by initiating a Call SetUp which 
routes the incoming call to the SN 42. At point `E1` the SN 42 examines a 
user profile associated with the Ext-DN which happens to also be the 
CallEd DN, to determine which additional DNs have been identified by the 
subscriber of the service as being virtual extensions to the Ext-DN. At 
point E2 the SN 42 initiates a Call SetUp via SSP 12 to the wireline 
Ext-DN and virtually at the same time, at point `J`, also initiates Call 
SetUp to a wireless DN. As a result of the Call SetUp to the wireline 
Ext-DN the SSP 12 again detects a termination attempt to the Ext-DN and 
for the second time in the call processing of the incoming call, sends (at 
`F`) a `termination attempt` switch event message, to the SCP 24 to 
request how to continue with the call processing of the incoming call. The 
SCP 24 upon detecting (at G1) that this is the second TAT, i.e. the second 
call attempt to the Ext-DN during the call processing of the incoming 
call, at G2 responds by returning to the SSP 12 an `Authorized 
Termination` message to instruct the SSP 12 to deliver (at `H`) the 
incoming call to the wireline Ext-DN. The wireline terminal associated 
with the Ext-DN is alerted in a conventional manner to the incoming call 
at `I`. Various methods of how the SCP 24 determines the second TAT will 
be discussed in detail later in the specification. 
At virtually the same time as the SN 42 initiates Call SetUp to the 
wireline Ext-DN, the SN 42 at point `J`, also initiates Call SetUp to the 
wireless DN found in the user profile. The SSP 12 at `K` proceeds with 
Call SetUp to the wireless DN over the network via `Feature Group D` trunk 
30 and the Mobile Switching Center (MSC) 22 of FIG. 1. At point `L` the 
MSC initiates delivery of the call to the wireless terminal and at point 
`L` the wireless terminal is alerted to the incoming call. 
At this point in the call processing, two terminals each of which has a 
different DN are simultaneously being alerted in response to the incoming 
call, the wireline DN (Ext-DN) as well as a wireless DN. There are 
effectively three call legs in progress as is best illustrated in FIG. 3; 
Call leg A between the SSP 12 and the SN 42 resulting from the Call SetUp 
to the SN, Call leg `B` between the SN 42 and the SSP 12 resulting from 
the Call SetUp to the wireline DN (the Ext-DN in this case) and Call leg 
`C` between the SN 42 and the MSC 22 resulting from the Call SetUp to the 
wireless DN associated with wireless terminal 23. Next in the call flow of 
FIG. 2 the wireline terminal (Ext-DN) goes off hook at `N`, before the 
wireless terminal and the call is answered on call Leg B as shown in FIG. 
2 at points `O-P`. The SN 42 at `P` connects Call Leg A to Call Leg B to 
complete the call `Q` and drops Call Leg C as is best illustrated in FIG. 
4. The SN 42 is still involved in the call and when either party in the 
call goes on hook the SSP 12 and the SN 42 proceed to take down call legs 
A and B. Service nodes 42 which have release trunking capabilities may 
send a release trunk message to the SSP 12 requesting it to connect the 
calling party to the Ext-DN terminal at the SSP (see FIG. 5) thus allowing 
the SN 42 to drop out of the call once the call is completed. 
FIG. 6 illustrates how the call flow of FIG. 2 would change if the wireless 
terminal answered the call before the wireline terminal. The call flow of 
FIG. 6 is substantially the same as that of FIG. 2 with differences 
occurring at N1, O1, P1 and Q1. The incoming call is established at Q1 and 
is connected to a wireless terminal. 
FIG. 7 is representative of a call flow where the Extended DN Service 
method anchors the Ext-DN to an existing wireless DN. Although wireless 
networks as of yet do not have true AIN many still follow the AIN call 
model and hence in substantially the way can make use of this invention 
today. For example in many wireless networks a Point in Call (PIC) trigger 
substantially equivalent of the AIN Termination Attempt Trigger (TAT) 
exists and is called `Location Request`. It is expected that in the near 
future the majority of the wireless networks will adopt AIN functionality 
directly for business reasons. For ease of understanding, the AIN trigger 
terminology, e.g. Termination Attempt Trigger has been used in the call 
flow of FIG. 7. The call flow follows from the description of the call 
flow of FIG. 2 except for the incoming call now arrives at the MSC 22 and 
it is the MSC 22 that interacts with the SCP 24 an SN 42 in the same way 
as the SSP 12 did in the embodiment of FIG. 2. As the call flow is 
substantially identical to that of FIG. 2, the reader is asked to refer to 
the detailed description for FIG. 2. 
Advantageous use of the Termination Attempt Trigger (TAT) is made in the 
embodiments of the invention illustrated in call flows of FIGS. 2 & 6 and 
similarly for FIG. 7. The TAT is sent twice by the SSP 12 to the SCP 24; 
the first time when the incoming call initially arrives at the SSP 12 
(point B of FIGS. 2 & 6) and the second time when the Service Node 42 sets 
up a call to the wireline DN at point F of FIGS. 2 & 6. The SCP 24 must 
distinguish therefore between the arrival of the first and second TAT 
since different processing by the SCP 24, is required for each. It is also 
expected that Service Providers will bill the DN to which this service is 
anchored to, i.e. the Ext-DN; in the example embodiment of FIGS. 2 & 6 the 
Ext-DN is the wireline DN and in FIG. 7 the Ext-DN is the wireless DN. 
Delivery of the correct billing information, therefore, for call legs to 
and from the SN 42 is desirable. Service Providers are as well expected to 
want to present the originating party DN to the CallEd wireline or 
wireless telephone. 
FIGS. 8 through 12 are substantially identical to FIG. 2 and respectively 
illustrate in further detail, five advantageous methods of handling the 
SSP 12 to SCP 24 AIN messaging and FGD trunk signaling used for the proper 
delivery of the basic incoming call. In FIGS. 8-12, identical network 
elements to FIG. 2, will carry the same feature number. Service Providers 
will choose among these methods based on a variety of considerations and 
tradeoffs. For example, the method illustrated in FIGS. 8, 9 & 10 require 
the use of a single AIN trigger but do not facilitate presentation of the 
calling (originating) DN to the wireless telephone. The methods 
illustrated in FIGS. 11 & 12 however provide the additional value of being 
able to present the originating party DN to the wireless telephone but 
require an additional AIN trigger. 
In FIG. 8, a control block including a timer is invoked and used by the SCP 
24 to store an incoming call history for a pre-determined amount of time. 
The SCP 24 includes logic to differentiate between the first and second 
TAT's (1A & 1G) and then uses the call history to facilitate the passing 
on of the stored originating DN to, in this case, the wireless telephone. 
In FIG. 8, the Ext-DN is anchored to the wireline DN and hence the AIN TAT 
is provisioned for the wireline DN at SSP 12. In response to an incoming 
call to the wireline DN,(the Ext-DN) the SSP 12 sends a TAT message 1A to 
the SCP 24. When a TAT message (1A or 1G) is received at the SCP 24, the 
SCP 24 first determines from the user profile associated with this CallEd 
DN, if the DN is associated with the Extended DN Service (and hence to be 
extended) and if so proceeds to check the TAT message to determine if the 
value found in the Calling field equals the value found in the CallEd 
field. This situation would normally not be expected as it indicates a 
party effectively attempting to call themselves. If the two fields are 
different, the SCP 24 creates a new control block 1B to store the 
originating or Calling DN and the CallEd DN (wireline DN in this example). 
The SCP 24 returns an AIN `Forward Call` message to SCP 12, instructing 
the SSP 12 to forward the call to the SN 42. The SSP 12 complies by 
initiating call set up 1D to SN 42 and creates call leg `A`. In order to 
correctly charge the Ext-DN subscriber, billing data is preserved on call 
leg `A` between SSP 12 and SN 42 by setting the `Charge Number Parameter` 
within the `Forward Call` message to contain the CallEd (Wireline/Ext-DN) 
DN. The SN 42 looks up all device DNs (two in this example) in a user 
profile associated with the CallEd DN (Wireline/Ext-DN) and initiates call 
setup to each one. SN 42 sets up call leg B (1F) to the Wireline DN and 
call leg C (1K) to the Wireless DN. In both instances the Wireline DN 
(Ext-DN) is used as the ANI field on the FGD or equivalent trunk. Call set 
up to the Wireline DN 1F, again initiates a TAT with a corresponding TAT 
message 1G being sent to the SCP 24. The SSP 12 creates the TAT message, 
tansparently passing on the WireLine DN in the CallEd DN field and also 
passes on the WireLine DN it received in the ANI field (1F), in the 
Calling DN field. When this TAT message (1G) is received at the SCP 24, 
the SCP 24 again determines from the user profile associated with this 
CallEd DN that the DN is associated with the Extended DN Service and this 
time also determines that within the TAT message the Calling DN field 
equals the value found in the CallEd DN field. This special situation 
indicates a second call attempt to the Ext-DN and causes SCP 24 to look 
for the associated control block. The SCP having determined that this is 
the second TAT or call attempt, instructs SSP 12 to proceed to deliver the 
call to the Wireline telephone by returning an `Authorize Termination` AIN 
message 1I. The presentation of the true originating party's DN to the 
Wireline telephone is made possible by the SCP 24 modifying certain 
parameters within the returned Authorize Termination` AIN message 1I. The 
SCP 12 normally would place the calling DN it receives in the TAT message 
1G into the calling DN parameter field in the Authorize Termination` 
message 1I. However, in this embodiment the SCP 12 inserts into the 
calling DN parameter field in the Authorize Termination` message 1I, the 
originating DN it received and recorded in the first TAT message 1A. The 
true originating party DN will be presented to the Wireline telephone if 
the wireline subscriber subscribes to the Caller Identification (CLID) 
service. The SCP 24 then releases or deletes the control block. (It to be 
noted however that the correct presentation of the originating DN to the 
wireless telephone is not possible with this particular embodiment.) 
FIG. 9 illustrates substantially the same call flow as for FIG. 8 with a 
variation on the mechanism used to detect the second TAT. The second TAT 
2G is distinguished from the first TAT 2A by the presence of a CallEd 
Party Station Type (CPST) field in the second TAT message 2A having a 
predetermined value assigned only to the Ext-DN service. A CPST value of 
40 has been used in the Call flow of FIG. 9 as it currently has 
unrestricted use and can be locally determined by a Service Provider. When 
the SN 42 originates the call leg to the wireline DN 2F it places an ANI 
Information Index (ANI.sub.-- II) parameter in the FGD trunk signaling 
data and sets its value to 40. When the call setup information is received 
2F, the SSP 12 places the value of the ANI.sub.-- II parameter in the CPST 
field of the TAT message 2G it sends to the SCP 24. On the call legs from 
the SSP 12 to the SN 42 (call leg A) and from the SN 42 to the Wireline DN 
(call leg B), the originating party DN is sent over the FGD trunk in the 
ANI signaling field thus enabling the SSP 12 to present the correct DN to 
the Wireline telephone if the Wireline customer subscribes to the Calling 
Identification (CLID) service. In order to correctly charge the Ext-DN 
(Wireline) subscriber for call legs A & B. the SCP 24 intervenes. When the 
SCP 24 returns the Forward Call message 2C, directing the SSP 12 to 
forward the call to the SN 42, the Wireline DN is provided as the Charge 
Number parameter for call leg A. Similarly, when the second TAT 2G message 
is handled 2H by the SCP 24, the Wireline DN is placed in the Charge 
Number field of the returned Authorize Termination message 2I. Correct 
billing information is preserved in call leg C from the SN 42 to the 
Wireless DN by having the SN 42 place the CallEd Wireline DN it received 
on call leg A, into the ANI field for call leg C (2k,2L). 
FIG. 10 is a more detailed version of the call flow of FIG. 2 and showing a 
third method of detecting the second TAT. Service providers prior to using 
the mechanism described in this embodiment need to provide a dedicated 
trunk between the SN 42 and the SSP 12 and as well to configure the SCP 24 
to recognize the dedicated trunk ID for this configuration. In a similar 
manner as for the mechanism shown in FIG. 9 call flow steps 3A to 3E of 
FIG. 10 follow the call flow steps 2A to 2E of FIG. 9. The SN 42 initiates 
call setup 3F to the Wireline DN on SSP 12 over the dedicated trunk 
between the SSP 12 and itself (SN 42). TAT messages in general to an SCP 
24 may provide trunk ID information for a particular incoming call. Unlike 
the first TAT message 3A where the trunk ID field is not present at all or 
is set to an ID representative of a `normal inter-office trunk`, the 
second TAT message 3G sent by the SSP 12 includes the trunk ID associated 
with the incoming call to the wireline DN. The trunk ID for calls setup by 
the SN 42 will always be the same and hence the SCP 24 upon receiving the 
second TAT can identify it as such by the fact that the trunk ID in the 
TAT message matches one of the dedicated or reserved trunks between the SN 
42 and the SSP 12. Delivery of the correct calling party DN (caller ID 
(CLID) service) to the Wireline terminal is achieved by having the SSP 12 
send the originating party DN in the ANI field 3D on the FGD trunk (call 
leg A) between the SSP 12 and the SN 42 and then to have the SN 42 include 
the originating party DN in the ANI field 3F on call leg B between the SN 
42 and the SSP 12. In order to correctly bill the subscriber having the 
Ext-DN (the wireline subscriber in this example) for call legs A & B (3D & 
3F respectively) the SCP 24 includes the Wireline DN (the Ext-DN) in the 
charge number field of the Forward Call message 3C sent to the SSP 12. 
When the second TAT message is processed (3G & 3H) the Wireline DN is then 
included in the charge number field of the Authorize Termination message 
on the call leg 3I between the SCP 24 and the SSP 12. Correct billing 
information is preserved on the call legs 3K & 3L from the SN 42 to the 
WireLess DN by including the Wireline DN (Ext-DN) in the ANI field of each 
call leg 3K & 3L. 
FIG. 11 is a more detailed version of the call flow of FIG. 2 and showing a 
fourth method of detecting the second TAT trigger. The call flow depicted 
in FIG. 11 is substantially identical to the call flow of FIG. 9 apart 
from the treatment of the call legs (4K, 4L, 4N, 4O) from the SN 42 to the 
WireLess DN. In the call flow of FIG. 11 a Public Office Dialing Plan 
(PODP) trigger is used to facilitate delivery of the originating party 
CLID information to the WireLess Terminal, while still preserving the 
correct billing DN (i.e. the Ext-DN in this example). A PODP trigger is 
provisioned for the trunk group(s) used for call legs (4K, 4L, 4N, 4O) 
from the SN 42 to the SSP 12 for the call to the WireLess Terminal. When a 
call leg 4K from the SN 42 to the WireLess terminal is set up on the PODP 
provisioned trunk to the SSP 12, the originating party DN is used as the 
calling party DN to preserve the CLID information to the WireLess 
terminal. For the SCP to be able to distinguish calls to the WireLess 
terminal from other calls from the Service Node 42, a special PODP DN is 
used as the CallEd DN on the call leg 4K. The PODP DN is effectively a 
transformation of the WireLess DN, i.e. the WireLess DN ({actual 
NPA}-NXX-XXXX) is mapped to a PODP DN ({special PODP NPA}-NXX-XXXX). When 
the SCP 24 receives an Info.sub.-- Analyzed (PODP) message 4L containing a 
PODP DN it uses the NXX-XXXX of this number to retrieve 4M the charge 
number and the actual area code for the WireLess DN from a subscriber 
profile within the SCP 24. The SCP 24 then replaces the PDOP DN with the 
actual retrieved WireLess DN in an Analyze.sub.-- Route message (4N) sent 
to the SSP 12. To preserve the correct usage charges for these call legs 
the AMA Alternate Billing Number is set to the WireLine DN (Ext-DN) and 
included in the Analyze.sub.-- Route message (4N). 
FIG. 12 is a more detailed version of the call flow of FIG. 2 and showing a 
fifth method of detecting the second TAT trigger. The call flow depicted 
in FIG. 12 is substantially identical to the call flow of FIG. 9 as well, 
apart from the treatment of the call legs (5K, 5L, 5N, 5O) from the SN 42 
to the WireLess DN. In the call flow of FIG. 12 an Off-Hook Delay (OHD) 
trigger is used (instead of the PODP trigger used in the call flow of FIG. 
11) to facilitate delivery of the originating party CLID information to 
the WireLess Terminal, while still preserving the correct billing DN (i.e. 
the Ext-DN in this example). A OHD trigger is provisioned for the trunk 
group(s) used for call legs (5K,5L,5N,50) from the SN 42 to the SSP 12 for 
the call to the WireLess Terminal. When a call leg 5K from the SN 42 to 
the WireLess terminal is set up on the OHD provisioned trunk to the SSP 
12, the originating party DN is used as the calling party DN to preserve 
the CLID information to the WireLess terminal. 
For the SCP to be able to distinguish calls to the WireLess terminal from 
other calls from the Service Node 42, a special OHD DN is used as the 
CallEd DN on the call leg 5K. The OHD DN is effectively a transformation 
of the WireLess DN, i.e. the WireLess DN ({actual NPA}-NXX-XXXX) is mapped 
to a OHD DN ({special OHD NPA}-NXX-XXXX). When the SCP 24 receives an 
Info.sub.-- Collected (OHD) message 5L containing a OHD DN it uses the 
NXX-XXXX of this number to retrieve 5M the charge number and the actual 
area code for the WireLess DN from a subscriber profile within the SCP 24. 
The SCP 24 then replaces the OHD DN with the actual retrieved WireLess DN 
in an Analyze.sub.-- Route message (5N) sent to the SSP 12. To preserve 
the correct usage charges for these call legs the AMA Alternate Billing 
Number parameter is set to the WireLine DN (Ext-DN) and included in the 
Analyze.sub.-- Route message (5N). 
Service providers (SP) of either a wireless or wired network may provide 
this service for their own respective customers or subscribers 
irrespective of the other network. For example a wired network SP may have 
a subscriber of their network identify a wired DN as the Ext-DN and 
provide one or more other wired DN's for the SP to alert simultaneously in 
response to incoming calls to Ext-DN. In such cases trunk connections to a 
wireless network are not a requirement. Similarly, a wireless network SP 
may have a subscriber of their network identify a wireless DN as the 
Ext-DN and provide one or more other wireless DN's for the wireless SP to 
alert simultaneously in response to incoming calls to the (wireless) 
Ext-DN irrespective of any inter-network trunk connections. 
It is also to be recognized that other embodiments are contemplated by the 
inventor. For example, a subscriber to such an Ext-DN service may desire 
the added flexibility of being able to select a sub group of terminals 
listed in a profile to be alerted in response to an incoming call, which 
may or may not include the Ext-DN being alerted. If for example a 
subscribers residence phone is the DN to which the service is anchored, 
i.e. the residence DN becomes the Ext-DN, and that subscriber knows that 
for the next few hours they will be traveling in their car, they may wish 
to have only their wireless DN alerted in response to an incoming call to 
their residence DN (the Ext-DN). This flexibility would allow important 
calls to a subscriber not to be missed simply because a family member may 
have answered in this example, the residence terminal before the 
subscriber in their car answered on their wireless terminal. 
Numerous ways in which to provide this flexibility are contemplated. For 
example a subscriber may either through an operator or an interactive 
dialing interface, modify at will their profile to add or delete directory 
numbers. With more recent technology such as the Internet, users can 
access personal profiles using World Wide Web forms or Java Applets. A 
subscriber profile may also be configured to contain a list of DN's and to 
associate a field with each DN which is modifyable by a subscriber at will 
to identify which DN's in the list are active (to be alerted) or not 
active (not to be alerted). Yet a further way in which to provide this 
flexibility would be to provide a subscriber with a plurality of profiles 
and the subscriber would then identify either through an operator or an 
interactive dialing interface, identify which one of the profiles is to be 
the active profile. A further extension of this would be to allow a 
subscriber to pre-select which one of a plurality of profiles is to be the 
active profile at different points in the day, thus minimizing the number 
of times a subscriber would need to interac with a profile management 
system. 
The implementation previously described in relation to the call flow 
illustrated in FIG. 8, would provide the flexibility and functionality in 
scenarios where the Ext-DN (the residence DN in the example above) is not 
to be alerted. The call flow of FIG. 8 would however vary slightly. In 
operation the Sn 42 would initiate call set up to the wireless DN but not 
to the wireline DN (Ext-DN) and hence call flow steps 1K and 1L would take 
place but steps 1F, 1G, 1H, 1L and 1J would not take place. Steps 1K and 
1L would result in the incoming call being delivered to the wireless DN 
but not to the Wireline DN, with the result that the timer associated with 
the control block 1B would time out. The control block 1B would then be 
dropped for that particular incoming call and the system would thus be 
ready for the next incoming call to the Ext-DN.