Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEM AND METIiOD FOR A
WIRELINE-WIRELESS
NETWORK INTERFACE
Technical Field
This invention relates to a system and method
for providing an interface between a wireline and
wireless network.
Background Art
Today, wireless and wireline services operate
completely independent of each other, each supported,
respectively, by a wireless and wireline network. Each
network provides the subscriber with a separate
telephone number and separate services, as well as
separate subscriber interfaces. Such service
bifurcation has resulted in duplicate transport,
switching, operations and billing for each network.
Current communication between the wireless and wireline
networks is limited to internetwork call delivery.
Internetwork call delivery occurs when a wireless (or
"mobile") subscriber calls a wireline directory number
(DN) or when a wireline subscriber calls a wireless
mobile identification number (MIN).
Personal Communication System (PCS)
development creates an opportunity for traditional
carriers to enhance wireline services by augmenting them
with wireless capabilities. These capabilities provide
services which enable subscribers to simultaneously
enjoy the benefits of wireless and wireline technology
integrated within a common service context. These
services, however, are not presently capable of
providing a single-number service which allows a
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subscriber to receive and make calls on either a
wireless or wireline telephone using a common telephone
number.
However, since wireline and wireless networks
have evolved from different architectural foundations
using different databases and protocols for call
processing, no internetwork interfaces exist between
wireless and wireline networks to support development of
hybrid wireless/wireline services. This in turn makes
the creation of an integrated network, with services
such as the single-number service, complicated due to
the lack of internetworking interfaces between the
wireless and wireline domains. Wireline networks use
Line Information Databases (LIDB) and Advanced
Intelligent Network (AIN) protocols for call processing,
whereas wireless networks use Home Location
Register/Visitor Location Register (HLR/VLR) databases
and IS-41 architecture protocols.
Another impediment is that both types of
networks manage calls independently without provisions
for handing-off calls from one domain to the other
depending upon subscriber location. For example, the
wireline architecture assumes that a subscriber is
always reachable via a directory number (DN) and the
wireless architecture assumes that a subscriber is
always reachable via a mobile identification number
(MIIv') .
Furthermore, development of single-number
wireless/wireline call service requires timely network
status information exchange between the wireless and
wireline networks, in order to perform efficient single-
number wireless/wireline call routing. Wireless
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communications are of great value to subscribers who
roam large geographic areas. However, some of these
wireless subscribers may desire to be accessed via a
wireline telephone number. Currently, no such
wireless/wireline internetworking interface exists which
is capable of supporting efficient network status
information exchange and routing between the wireless
and wireline networks.
Internetworking functions must also support
the processes of updating location status information
concerning subscriber movement between wireline and
wireless networks and then routing single-number calls
to the appropriate network based upon current subscriber
location. Robust single-number service requires
interaction between the wireless and wireline networks
so that when the mobile handset associated with the MIN
is activated, the wireless network informs the wireline
network. Thus, to satisfy a subscriber who is roaming
in the cellular network and would like calls incoming to
his directory number delivered directly to him, requires
coordination between the two networks. No current
mechanism exists to allow internetworking.
US Patent No 5,353,331 issued to Emery et al
discloses a personal communications service using
wireline/wireless integration. However, in this system,
a traditional wireless feature -- the Home Location
Register -- is located in a traditional wireline
feature, the Integrated Service Control Point (ISCP).
This approach means that the two networks are combined
and controlled from the wireline ISCP. In effect, the
ISCP acts like a mobile service controller for the
subscriber when the subscriber is roaming. Thus, under
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this disclosure, the two networks are actually a single
entity.
Consequently, a need has developed to provide
a method and system for providing an improved method of
interface to act between the separate wireless and
wireline networks which permits the coordination and
cooperation needed for a single-number service. This
interface method incorporates enhanced IS-41
architecture and protocol extensions to provide support
for a new architectural entity, a Wireline Location
Register (WLR), which is a database located in the
Service Control Point (SCP) of the wireline network.
The WLR is able to communicate with the HLR for exchange
of wireless/wireline network status information.
Development of these extensions will allow users to
simultaneously enjoy the benefits of wireless and
wireline technologies integrated within a single-number
service concept.
Summary Of The Invention
It is an object of the present invention to
provide a method and system to provide an interface
between the wireline and wireless communication
networks.
It is another object of the present invention
to provide a method and system to provide a single-
number service between the wireline and wireless
communication networks.
It is a further object of the present
invention to provide a method and system as described
above which gives a subscriber the perception of a
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single hybrid wireless/wireline service, even though the
service may actually be delivered by two separate
networks but integrated to support the appearance of the
single-number service concept.
It is still a further object of the present
invention for a single-number service through which a
subscriber can be reached by a calling party dialing a
single-telephone number assigned to the subscriber,
regardless of the subscriber's location in the wireline
l0 or wireless networks.
It is yet still a further object of the
present invention to provide a single-number call
routing service adapted for use with an internetwork
interface having mapping and address routing
capabilities for routing a wireline DN call to a
wireless number (MIN), whenever the single-number
subscriber is registered within the wireless domain.
It is yet another object of the present
invention to provide a method and system as disclosed
above which are further adapted for use in cooperation
with existing wireline switches in an Advanced
Intelligent Network (AIN) so as to minimize the need for
additional network components.
In carrying out these and other objects and
goals of the present invention, a system is disclosed
for providing an interface between the wireless and
wireline communication networks. This interface
provides for supporting single-number services and
forwarding a call incoming to a subscriber's designated
single telephone number to a routing destination number
based on the subscriber's current location. A system is
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provided for an interface between wireless and wireline
networks for supporting single-number services and the
exchange of network status information in order to route
a call incoming to a subscriber's single telephone
number to either a subscriber' s mobile unit through a
Mobile Services Controller (MSC) or to a subscriber's
customer premises equipment (CPE) through a Service
Switching Point (SSP)- depending on the location of the
subscriber.
The system includes a Wireline Location
Register (WLR) located in the wireline communication
network and in electrical communication with the SSP for
storing subscriber routing information and subscriber
registration status data. Further provided is a Home
Location Register (HLR) located in the wireless
communication network and in electrical communication
with the WLR and the MSC for storing and communicating
to the WLR subscriber routing information and subscriber
registration status data. Also included is a service
control point (SCP) located in the wireline
communication network and provided in electrical
communication with the WLR and the SSP. The SCP is
operable to retrieve the subscriber routing information
and provide the subscriber routing information to the
SSP. In another embodiment, included is a Visitor
Location Register (VLR) located in the wireless
communication network and provided in electrical
communication with the HLR and the MSC. The VLR enables
the WLR to issue a query to the HLR requesting routing
destination for subscribers who are wireless registered,
which allows the delivery of the call to the appropriate
wireless or wireline telephone number destination.
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In further carrying out the above objects,
features and advantages of the present invention, there
is provided a method for providing an interface between
the wireless and wireline networks in order to support
a single-number service to forward a call incoming to a
subscriber's designated single telephone number to a
routing destination number based on the subscriber's
current location. A subscriber mobile registration
status is stored in a wireline location register (WLR)
located in the wireline communication network. The WLR
is in electrical communication with a wireline switch
and a Home Location Register (HLR). A wireline switch
is monitored to detect predetermined AIN triggers. A
registration query is generated at the wireline switch
for receipt by the WLR upon detection of the
predetermined AIN triggers, so as to request subscriber
mobile registration status data. The subscriber mobile
registration status is retrieved upon receiving the call
incoming to the subscriber's designated single telephone
number.
In keeping with the invention, wireline DN
calls are routed to wireline destinations in response to
the subscriber's WLR mobile registration status data
indicating that he/she is wireline registered. A first
mobile query at the WLR to the Home Location Register
(HLR) of the wireless network in response to the
subscriber mobile registration status indicating that
the subscriber is wireless registered, so as to request
a current subscriber mobile location. A second mobile
query is generated at the HLR to the Mobile Switching
Center (MSC) where the subscriber is registered, so as
to request a wireless routing destination number. A
wireless routing destination number is communicated from
the MSC to the WLR through the HLR. The call is routed
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from the wireline switch to the MSC to the wireless
routing destination number.
The single-number internetworking function can
be subdivided into the following areas: Location
Determination; DN/MIN Mapping; Call Routing; and
Services Synchronization. Implementation of single-
number service requires development of wireless/wireline
internetworking functions, such as address mapping
logic, which map DN' s to MINS' s whenever subscribers are
within the wireless domain. Furthermore,
wireless/wireline internetworking logic must support
timely location status information exchange concerning
subscriber movement between network domains.
The above objects and other objects, features
and advantages of the present invention are readily
apparent from the following detailed description of the
best modes for carrying out the invention when taken in
connection with the accompanying drawings wherein like
reference numerals correspond to like components.
2 o Brief Description Of The Drawings
Figure 1 is a schematic diagram of a system
according to the present invention for providing an
integrated wireline/wireless network to subscriber's of
a single-number service;
Figure 2 is a block diagram of the method
steps of the present invention.
Figure 3 is a call flow diagram illustrating
wireless subscriber registration in a manner according
to the present invention;
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Figure 4 is a call flow diagram illustrating
wireless subscriber deactivation in a manner according
to the present invention;
Figure 5 is a call flow diagram illustrating
a call complete to a wireless subscriber in a manner
according to the present invention;
Figure 6 is a call flow diagram illustrating
a call to a busy wireless subscriber in a manner
according to the present invention;
Figure 7 is a call flow diagram illustrating
wireless subscriber call delivery inactive in a manner
according to the present invention;
Figure 8 is a call flow diagram illustrating
call waiting to a wireless subscriber in a manner
according to the present invention;
Figure 9 is a call flow diagram illustrating
wireless subscriber calling home in a manner according
to the present invention; and
Figure 10 is a call flow diagram illustrating
an unanswered call to a registered wireless subscriber
in a manner according to the present invention.
Best Modes For CarrJ~ing Out The Invention
With reference to Figure 1 of the drawings,
there is provided a schematic illustration of an
integrated wireline/wireless network system according to
the present invention which is designated generally by
reference number 10.
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With further reference to Figure 1, a
representative diagram of Advanced Intelligent Network
(AIN) architecture is provided for use in a wireline
Public Switched Telephone Network (PSTN), and as part of
integrated network system 10. The AIN architecture
referred to is generally designated by reference numeral
12. Architecture 12 is known to those skilled in the
art to permit subscriber services to be extended
throughout the wireline network. Specifically,
architecture 12 is utilized for updating the subscriber
service profile which contains subscriber specific data
regarding how calls should be handled.
Further, as those skilled in the art will
recognize, architecture 12 is implemented with a Common
Channel Signaling (CCS) protocol 18, such as Common
Channel Signaling System No. 7 (hereinafter referred to
as "SS7 protocol"). The SS7 protocol is an out-of-band
signaling path comprised of various packet switching
elements 20 and transmission signaling links 18, some of
which are shown in architecture 12. As more fully set
forth in Figure 1, the Customer Premises Equipment (CPE)
device of the caller and subscriber is represented and
designated as telephone 14. However, it is clear that
the CPE's may include a modem, a facsimile machine, a
voice messaging peripheral, or any other
telecommunication equipment that may receive or transmit
voice or data. As those skilled in the art will
recognize, in operation, each telephone l4 is provided
in electrical communication with a Service Switching
Point (SSP) 16.
SSP 16 is generally a node (usually the
subscriber's local switch/central office switch) that is
provided in electrical communication with CPE 14 through
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the PSTN. SSP 16 is an AIN capable switch. SSP 16
recognizes the predetermined AIN "triggers" used when a
subscriber or user invokes a subscriber service. More
particularly, in the present invention, SSP 16
recognizes the triggers associated with a calling party
dialing a subscriber'.s telephone number designated as a
single-number service DN. SSP 16 further communicates
with SCP 22 (discussed herein) to operate the service.
The electrical communication between CPE 14 and SSP 16
is made via signaling links 18. As shown generally in
Figure 1, SSP 16 is further provided in electrical
communication with SCP 22 via Signal Transfer Points
(STP's) 20 and signalling links 18. STP's are packet
switches used to route signaling messages within
wireline network 12 as well as route call routing
instructions to SSP 16. In still other embodiments,
features such as an Intelligent Peripheral (not shown)
which are well known in the art may also be
incorporated. A Service Control Point (SCP) 22 is
incorporated as shown in Figure 1 and as further
discussed below.
SCP 22 is a node which contains the service
logic and associated data support needed to execute
required customer and subscriber services, such as the
single-number service of the present invention. The
service logic contained in SCP 22 includes a service
profile for each subscriber or subscription service.
SCP 22 may also be classified as an Integrated Service
Control Point (ISCP) which is an integrated system well
known in the art. Service logic stored in SCP 22 is
accessible to each predetermined SSP 16 in the telephone
system or network. SCP 22 is further provided in
electrical communication with the Wireline Location
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Register (WLR} 24 database more fully disclosed herein.
Preferably, WLR 24 is located in SCP 22.
Again referring to Figure 1, the wireless
network portion of system 10 is designated generally as
reference number 30. Wireless network 30 consists of
four basic components: a cell site containing a
controller and radio transceiver; system
interconnections; and mobile or portable units. Mobile
Switching Center (MSC} 32 (or Mobile Telephone Switching
Center (MTSC)) is known to those skilled in the art as
a digital telephone exchange which controls the
switching between the PSTN and mobile cell sites for all
wireline-to-mobile, mobile-to-wireline, and mobile-to-
mobile calls. In operation, when MSC 32 receives a call
from the PSTN which is directed to a MIN, MSC 32
deciphers the telephone number dialed by the wireline
user and alerts the controllers at all cell sites to
page a corresponding mobile unit 40. Similarly, when
mobile unit 40 places a call, the MSC accepts the
dialing data from the cell site controller and dials the
desired number for transmission to the PSTN. MSC 32
also processes mobile registration status data received
from the cell site controller, switches calls to other
cells, processes diagnostic information, and compiles
mobile billing statistics.
Typical wireless networks 30 include multiple
adjoining cells each of which contains at least one cell
site controller which operates under the direction of
the MSC 32. The cell site controller manages each of
the radio channels at the site, supervises calls, turns
the radio transmitter and receivers on and off, injects
data onto the control and user channels, and performs
diagnostic tests on the cell site equipment. Cells may
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contain multiple radio transmitters and radio receivers.
As those skilled in the art will further recognize, in
operation multiple receivers are generally tuned to the
same frequency. However, the receiver which locates the
stronger radio signal is continuously selected.
Furthermore, cells typically have at least one radio
channel that transmits control data to and receives
control data from the mobile units. This control data
advises the mobile unit that a call is coming from the
MSC or conversely, advises the controller that a mobile
telephone user desires to place a call. To complete the
connection, the controller uses the control channel to
advise the mobile unit which user channel had been
assigned to the call.
MSC 32 is the functional equivalent to the SSP
16 of the wireline network. MSC 32 also retrieves all
necessary data to respond to subscriber call requests
from three databases -- the Home Location Register (HLR)
34, the Visitor Location Register (VLR) 36, and the
authentication center (AC) 38 -- each discussed more
fully herein. In turn, MSC 32 provides databases 34, 36
and 38 with updated information on subscriber mobile
registration status and location.
To register a subscriber in the wireless
network 30, MSC 32 ascertains whether a subscriber is
present in the wireless network 30 when the subscriber
places a call via mobile unit 40, receives a call via
mobile unit 40, or by automatic registration.
Specifically, each time mobile unit 40 is powered on or
a call is originated from mobile unit 40, certain
information is transmitted to MSC 32, including the
unit's MIN, Electronic Serial Number (ESN) and System
Identification (SID).
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The Home Location Register (HLR) 34 is a
master database for storing data related to each mobile
subscriber, such as the subscriber profile and mobility
information together with their relevant permanent
(static) data, such as access capabilities and
subscriber services. In addition, HLR 34 is in
electrical communication with and provides MSC 32 with
information about the MSC 32 service area where the
mobile unit 40 is actually located (temporary or dynamic
data) to allow incoming calls to be routed immediately
to the called subscriber's mobile unit 40.
The Visitor Location Register (VLR) 36 is a
functional element which corresponds to one or several
MSC's 32. VLR 36 is in electrical communication with
MSC 32 and HLR 34. VLR 36 contains detailed data on
location and service data regarding each subscriber
entering its coverage area for routing which is used for
incoming and outgoing calls. This allows MSC 32 to set
up incoming and outgoing calls and is designed so
information can be moved to MSC 32 to expedite call
implementation. VLR 36 is a dynamic subscriber
database, exchanging considerable amounts of data with
its related HLR 34. Data stored in VLR 36 follows
subscribers when they enter another VLR area.
Querying of HLR 34 is somewhat different. The
gateway MSC has to query HLR 34 after receiving the call
setup message from the PSTN wireline network. During
the querying, the call is suspended as its destination
is unknown. The authentication center (AC) 38 is
needed to store key information and security database
information. AC 38 is in electrical communication with
HLR 34.
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As is well-known in the art, the IS-41
architecture standard defines signalling, mobility
control and handoff rules throughout the wireless domain
30.
INTEGRATED SYSTEM AND ARCHITECTURE
To achieve the desired wireless/wireline
network interface and single-number service
functionality contemplated according to the present
invention, there is provided integrated
wireless/wireline network 10 as shown in Figure 1. As
recognized by those skilled in the art, in order to
support the operation of the wireless/wireline interface
of the wireline WLR network element 24 and its
communication with the wireless HLR 34, protocol
extensions are provided which are based on IS-41 Rev. C
architecture. It is through these protocol extensions
(collectively designated as "IS-41+") that messaging and
signalling functions are handled by WLR 24, and
communicated to and from WLR 24. The IS-41+ integration
architecture supports the application layer
communications between the wireless 30 and wireline 12
networks to implement the single-number service
according to the present invention.
Thus, in accordance with the present
invention, WLR 24 and HLR 34 are interconnected via
signaling trunks and circuits and use messaging
techniques to handle the single-number service mobility
functions. This signalling connection 50 between WLR 24
and HLR 34 minimizes (if not eliminates) upgrades to
existing switches and leverages existing AIN SSP and SCP
functionalities to integrate the disparate wireless and
wireline networks in a unified manner to support 10-
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digit DN single-number wireless/wireline call routing
based upon current subscriber location.
The IS-41+ architecture can use a variety of
transport options and configurations. As shown in
Figure 1 and referenced above, the system 10 according
to the present invention is adapted to be used with
existing wireline switches such as SSP 16 as described
above. As will be appreciated by those skilled in the
art, IS-41+ disclosed herein in accordance with the
present invention has the traditional functionality of
IS-41 plus the added functionality of allowing WLR 24 to
directly communicate with HLR. More particularly, the
term "IS-41+" disclosed herein is used to signify the
added functionality of supporting WLR 24 and its
messaging features with HLR 34. The IS-41+ architecture
is well-poised for a smooth transition to the evolving
Personal Communications System and other integrated
systems.
WLR 24 is a database preferably resident
within Service Control Point (SCP) 22 of wireline
network 12. WLR 24 represents a combination of IS-41
HLR/VLR functionality implemented within a single
wireline network element. First, the HLR-functionality
of WLR 24 supports message exchange procedures enabling
wireline network 12 to determine when single-number
service subscribers become registered or become
deactivated within wireless network 30. Second, the
VLR-functionality enables WLR 24 to issue location
request messages to HLR 34 to determine routing location
information for single-number subscribers registered in
wireless domain 30.
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WLR 24 eliminates unconditional querying of
HLR 34 by wireline network 12 to determine registration
status and routing information. IS-41+ also supports
service synchronization between HLR 34 and WLR 24
providing the appearance of a singular seamless service
between wireless 30 and wireline 12 networks.
Single-number service subscribers thereby receive
service in both the wireless 30 and the wireline 12
domain. Further, subscribers are permitted to keep
their existing wireline DN's, which are automatically
mapped to an associated, and preferably, unlisted
wireless Mobile Identification Number (MIN) when the
subscriber is wireless registered. Calls incoming to
the subscriber's single-number DN will not ring at the
subscriber's designated wireline base (i.e. home, work,
etc.) while the associated mobile unit 40 is registered
within the wireless domain 30.
Single-number functions supported by the
wireless/wireline service logic program must support the
following wireless/wireline internetworking functions:
Location determination; DN/MIN Call Mapping; Call
Routing; and Services Synchronization. The protocol
enhancements provide a technical approach to implement
wireless/wireline integration providing support for
single-number service compatible with principles of IS-
4l and AIN.
Generally, SSP 16 is connected to MSC 32 by
trunk circuits 52, while wireless components such as MSC
32, HLR 34, VLR 36 and AC 38 are connected with each
other by IS-41 Mobile Application Part (MAP) protocols
42 operating over SS7 or X.25 networks. IS-41 data
trunks are packet switched networks, having either X.25
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or SS7 type transport options. MSC 32 may also connect
to STP's 20 by SS7 links.
OPERATION
With reference now to Figure 2 of the
drawings, the method of operation according to the
present invention and, in particular, the interfacing
functionality.will be described in greater detail.
As shown in Figure 2 , a method according to
the present invention includes the steps of storing a
subscriber's mobile registration status in a wireline
location register (WLR) 24 which is located in SCP 22 of
the wireline communication network, as shown in block
60. WLR 24 is in electrical communication with a
wireline switch (such as SSP 16) and a Home Location
Register (HLR) 34. SSP 16 monitors to detect
predetermined AIN triggers as shown in block 62.
Further, as shown in block 64, a registration query is
generated at SSP 16 for receipt by the WLR 24 upon
detection of the predetermined AIN triggers, so as to
request subscriber mobile registration status. The
subscriber mobile registration status is retrieved upon
SSP 16 receiving the call incoming to the subscriber's
designated single telephone number.
In keeping with the invention, block 66 shows
that the call from SSP 16 is routed to a wireline
destination number stored in WLR 24 in response to the
subscriber mobile registration status data indicating
that the subscriber is wireline registered. Referring
to block 68, a first mobile query at WLR 24 to the Home
Location Register (HLR) 34 of wireless network 30 in
response to the subscriber mobile registration status
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indicating that the subscriber is wireless registered,
so as to request a current subscriber mobile location.
As shown in block 70, a second mobile query is generated
at the HLR 34 to the Mobile Switching Center (MSC) 32
where the subscriber is registered, so as to request a
wireless routing destination number. A wireless routing
destination number is communicated from MSC 32 to WLR 24
through HLR 34 as shown in block 72. The call is routed
from SSP 16 to MSC 32 to the wireless routing
destination number as shown in block 74.
Further provided herein are descriptions of
call flows operable to perform various functions
contemplated for the system and methods disclosed above
in accordance with the present invention. In
particular, the location determination, mapping, call
routing and synchronization functionalities necessary to
support the network interface will be described in
further detail. As reference is made to Figures 3-10,
it is noted that queries and affirmative messages are
generally designated by all uppercase letters, while
query and message responses are generally shown in
smaller case letters.
Location Determination
The location determination functionality
according to the present invention represents the
interworking functions between wireline 12 and wireless
networks responsible for exchange of mobile
subscriber registration and location information. For
example, if mobile unit 40 registers for cellular
30 operation as previously stated, wireline network 12 must
be capable of determining, through location status
information exchange, that the subscriber is presently
reachable through wireless network 30. In such cases,
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all single-number wireline DN call terminations must be
mapped to an appropriate wireless MIN/mobile unit.
Likewise when mobile unit 40 is deactivated or
deregistered, wireline network 12 must be capable of
determining, through location status information
exchange, that all single-number calls should be
directed or re-mapped to the DN (DN termination).
Note that the IS-41 protocols and
messages (e. g. IS-41 Rev. C, REGNOT and MSINACT, etc.)
can be used as a basis to implement location status
information exchange between HLR 34 and WLR 24. To
implement the single-number service, location status
information must be maintained by and synchronized
between both the wireless 30 and wireline 12 networks.
Without IS-41 protocol extension development, wireline
network 12 does not have an efficient way to determine
whether or not a single-number mobile unit is registered
within wireless domain 30.
Figure 3 illustrates the call flows involved
in registering mobile unit 40 in wireless network 30.
As illustrated in Figure 3, a subscriber turns on his or
her mobile unit 40 (not defined by IS-41) within
proximity of MSC 32 (shown as 80). MSC 32 sends a
Registration Notification ("REGNOT") message to its
corresponding VLR 36 (shown as 82), which in turns
forwards it to HLR 34 (shown as 84), indicating that the
subscriber has become wireless registered in wireless
network 30.
In further keeping with the invention, upon
receiving the "REGNOT" message, HLR 34 forwards a
Registration Notification Response ("regnot response")
(shown as 86) back to VLR 36 which in turn forwards it
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to MSC 32 (shown as 88). Upon successfully registering,
HLR 34 relays the REGNOT message to the WLR 24
indicating that the subscriber has transitioned from
wireline network 12 to the subscriber's mobile unit
40/MIN of wireless network 30 (shown as 90). Upon
receiving the message, WLR 24 sets the single-number
subscriber as wireless registered, and returns a "regnot
response" message to the HLR (shown as 92). REGNOT
stimulates WLR 24 to route all subsequent DN terminated
calls to the wireless domain 30, as long as the
subscriber remains wireless registered.
Figure 4 illustrates the call flows involved
in deactivating a wireless subscriber from wireless
network 30. Referring now to Figure 4, when the
wireless registered subscriber deactivates mobile unit
40, the deactivation is detected by MSC 32 (shown as
94 ) . MSC 32 then transmits a Mobile Service Tnactive
("MSINACT") message to VLR 36 indicating the
deactivation (shown as 96) which in turn forwards this
message to HLR 34 (shown as 98). Upon receiving the
message, HLR 34 returns a Mobile Service Inactive
Response ("msinact response") to VLR 36 (shown as 100)
which in turn returns it to MSC 32 (shown as 102).
Meanwhile, HLR 34 sends MSINACT to WLR 24 across IS-41+
interface 50 (shown as 104), indicating that the
subscriber is no longer active in wireless network 30
and that wireline network 12 must now deliver all
single-number subscriber calls to subscriber's CPE 14 in
wireline domain 12. Lastly, a "msinact response" is
returned to HLR 34 from WLR 24 (shown as 105).
CALL MAPPING AND ROUTING
Mapping provides the single-number service
subscriber with the capability to map a wireline DN call
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to a wireless mobile unit 40/MIN for purposes of call
delivery to the subscriber who is currently located
within wireless network 30. Again, note that the MIN
may be treated as an unpublished number in the single-
s number service because a calling party will only dial
the DN associated with the subscriber and not the MIN.
Furthermore note that the reverse mapping (MIN to DN) is
required in order to relate wireless usage to a common
wireline DN telephone bill.
Wireless/Wireline call routing represents an
internetworking function responsible for delivering
single-number DN calls to the appropriate wireless 30 or
wireline 12 network based upon current subscriber
location information. The wireless/wireline call
routing decision is made based upon location status
information maintained within WLR 24, previously
described. Note that since MIN's are expected to be an
unpublished number, the wireless network 30 is not
expected to perform call termination based upon MIN's.
In fact, the wireless network can be prohibited from
performing MIN call terminations to ensure that wireline
network 12 maintains call termination control. The
wireless/ wireline call routing function is performed by
AIN/SCP service logic using registration status
information stored within WLR 24.
If a subscriber is wireless registered as
previously discussed, the subscriber is located (or
subscriber's mobile unit 40 is active) in wireless
network 30 and all DN call terminations must be mapped
to a corresponding MIN and delivered through the
wireless network 30. If a subscriber is within
wireline network 12, all DN call terminations must be
delivered through wireline network 12. According to the
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present invention, mapping responsibility is distributed
between both wireline 12 and wireless 30 networks. Note
that this network distribution approach is probably the
most efficient architecture to implement wireless/
wireline DN/MIN address mapping. This results from the
fact that translations can be made by direct look-up
without searching.
Figure 5 illustrates the call flow when a call
incoming to a single-number service subscriber's DN is
complete to a subscriber's mobile unit 40 registered in
the wireless network. Referring to Figure 5, a calling
party (CgP) calling from telephone 48 dials a 10-digit
DN (NPA-NXX-XXXX) belonging to the single-number service
subscriber, which is received by local switch SSP 16 for
handling (shown as 108). In an effort to minimize, if
not eliminate, modification to the base of embedded
switches, SSP 16 interrupts the digits and is adapted to
monitor for detection of predetermined AIN triggers,
like the Termination Attempt Trigger ("TAT"); whereupon
SSP 16 issues a Termination Attempt Query to SCP 22,
which is in electrical communication with V~1LR 24 (shown
as 110). WLR 24 receives this query, determines that
the subscriber is wireless registered (as discussed in
association with Figure 3, above), and issues a Location
Request Query ("LOCREQ") to HLR 34 to determine the
location (a wireless routing number or address) for the
subscriber (shown as 112).
In keeping with the present invention, upon
receipt of LOCREQ, HLR 34 issues a Routing Request Query
("ROUTREQ") to MSC 32 where the subscriber is registered
(shown as 114). MSC 32 receives ROUTREQ from HLR 34 and
returns a Routing Request Response ("routreq response")
message containing a Temporary Location Destination
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Number (TLDN) fox routing the call to the wireless
registered subscriber (shown as 116). HLR 34 receives
"routreq response" and returns a Location Request
Response ("locreq response") to WLR 24 containing the
TLDN (shown as 118). SCP 22 returns an AIN Forward Call
response to SSP 16 containing TLDN as the routing number
(shown as 120). SSP 16 routes the incoming call to the
TLDN at MSC 32 (shown as 122). MSC 32 initiates paging
and alerts the wireless registered single-number
subscriber (or called party CdP) at mobile unit 40 of
the routed call (shown as 124). The subscriber answers
the incoming call at mobile unit 40 and the call
connection is established with the calling party from
telephone 48 (shown as 126). It is contemplated for the
call flows which terminate at mobile unit 40, described
herein, that a plurality of wireless mobile units 40 may
be provided, each having a unique MIN . In that case ,
each destination is alerted and the call is terminated
to the mobile unit which first answers the call.
Figure 8 illustrates a message flow similar to
that described above in association with Figure 5, with
the modification that the single-number service
subscriber is also a call-waiting service subscriber.
Call-waiting is a subscriber service well-known in the
art. The message flow steps of Figure 5 which are
common for Figure 8 are similarly numbered. Initially,
Figure 8 shows an active call connection 128 between
calling party from telephone 47 to mobile unit 40. A
second calling party 48 proceeds to make a call to the
single-number service subscriber as outlined in
association with Figure 5, except that instead of MSC 32
paging to alert mobile unit 40, MSC initiates call-
waiting alert of mobile unit 40 (shown as 130). The
subscriber then answers the call and a second call
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connection is established with second calling party 48
(shown as 132).
SERVICES SYNCHRONIZATION
Seamless services synchronization requires
that service parameter changes made in wireless network
30 must be reflected within wireline network 12, and
vice versa. The IS-41 protocol and messages for feature
related treatment (FEATREQ) can be used as a basis to
implement wireless/wireline service synchronization
between the wireless network (HLR) and the wireline
network (WLR) .
Referring now to Figures 6 and 7, provided are
call flow diagrams for a call complete to a single-
number subscriber who is registered in the wireless
network (as described in association with Figure 5), but
who is either (1) busy on an active call (Figure 6); or
(2) has inactive call delivery capability (Figure 7).
Similar functions between Figures 6 and 7 have like
reference numerals.
As shown in Figures 6 and 7, calling party 48
dials the 10-digit number (NPA-NXX-XXXX) for the single-
number subscriber, which is received by local switch SSP
16 for handling (shown as 134). SSP 16 interrupts the
digits which is monitored for the detection of
predetermined AIN triggers, like the Termination Attempt
Trigger ("TAT"); whereupon SSP 16 issues a Termination
Attempt Query to SCP 22, which is in electrical
communication with WLR 24 (shown as 136). WLR 24
receives this query, determines that the subscriber is
wireless registered (as discussed in association with
Figure 3, above), and issues a Location Request Query
("LOCREQ") to HLR 34 to determine the location (a
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wireless routing number or address) for the subscriber
(shown as 138). Upon receipt of LOCREQ, HLR 34 issues
a Routing Request Query ("ROUTREQ") to MSC 32 where the
subscriber is registered (shown as 140).
If the single-number subscriber is wireless
registered but busy on an active call, the MSC 32
returns to HLR 34 a "routreq response". In Figure 6,
for a mobile unit 40 which is busy on an active call,
the "routreq response" contains an access denied
indicator (ACCDEN) due to a busy status for the wireless
registered subscriber (shown as 142); In Figure 7, for
a mobile unit 40 which has inactive call delivery, the
"routreq response" contains an access denied indicator
(ACCDEN) due to a call delivery inactive status for the
subscriber (shown as 143). HLR 34 will in turn send to
WLR 24 a "locreq response" containing the ACCDEN due to
either a busy status (Figure 6) or an inactive status
(Figure 7) (shown as 144 and 145, respectively). SCP 22
returns an AIN Authorize Termination response to SSP 16
containing the DN retrieved from WLR 24 as the
terminating number (shown as 146) . SSP 16 routes the
single-number call to the DN (shown as 148) where
wireline DN unit 14 answers the incoming call and call
connection is established with the calling party at
telephone 48 (shown as 150).
Referring to Figure 9, call flows are
established for a wireless registered single-number
subscriber calling his or her own single-number DN.
Special AIN/SCP service logic is required to enable a
wireless registered single-number subscriber, operating
mobile unit 40, to call the corresponding single-number
DN in order to prevent the DN call from being re-routed
back to the registered mobile unit 40 (MIN). As shown
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in Figure 9, mobile unit 40 dials the 10-digit single-
number DN (shown as 152). MSC 32 interrupts the dialed
digits and routes the call to the serving SSP 16 (shown
as 154). SSP 16 interrupts the digits, encounters a TAT
and issues a Termination Attempt Query to SCP 22 (shown
as 156 ) . WLR 24 receives this query, determines that
the subscriber is wireless registered, that the mobile
registered subscriber is actually calling his personal
single-number DN, and SCP 22 returns and AIN Authorize
Termination response to SSP 16 containing the DN as the
terminating number (shown as 158). SSP 16 then routes
the single-number call to the DN (shown as 160),
enabling a connection between the subscriber's mobile
unit (MIN) to call his single-number DN (shown as 162).
Lastly, Figure 10 illustrates a call flow
reflecting the pattern of a call unanswered by a
registered wireless subscriber with an active mobile
unit 40. The beginning of this message flow is similar
to that of Figure 5, and the message flow steps of
Figure 5 which are common for Figure 10 are similarly
numbered. As shown, a calling party 48 proceeds to make
a call to the single-number service subscriber as
outlined in association with Figure 5 in steps 108-120.
However, upon paging and alerting mobile unit 40 by MSC
32, there is no answer by the subscriber (shown as 164).
As a result of there being no answer by the subscriber
of mobile unit 40, MSC 32 seeks to redirect the call
back to the subscriber's'wireline DN 14. MSC 32 issues
a redirection request query (REDREQ) to WLR 24
requesting re-routing of the call, the redirection
request containing a redirection reason (REDREASON) (as
shown in 166).
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Because SSP 16 has previously given control of
the call to wireless network 30 and has no memory of the
call, WLR 24 is unable to retain re-routing information.
Thus a redirection request response (redreq response)
containing an error message is returned to MSC 32 (as
shown in 168). MSC 32 issues to WLR 24 a transfer to
number request query (TRANUMREQ) containing a
redirection reason (REDREASON) (as shown in 170), since
call forwarding has been activated to invoke forwarding
of unanswered calls. As previously mentioned, SSP 16
has given control of the call to wireless network 30.
In order to maintain the appearance of seamless network
integration, call forwarding is used to get the call
back to subscriber's wireline DN 14 in wireline network
12. WLR 24 receives the TR.ANUMREQ and returns a
"transfer to number request response" containing the
subscriber's wireline DN as the number to which the call
is to be re-directed to on the "call forward - do not
answer (CFDA)" condition (as shown in 172). MSC 32
receives the "transfer to number request response"
(tranumreq response) indicating that the call should be
transferred to wireline DN 14 on the CFDA condition.
MSC 32 directs SSP 16 to route the call to the
subscriber's wireline DN 14 (as shown in 174). Finally,
SSP 16 establishes a connection between the calling
party 48 and the subscriber's wireline DN 14, since
mobile unit 40 did not answer the call initially (as
shown in 176).
As those skilled in the art will recognize,
the above discussion is one possible solution for when
a call delivered to a subscriber's mobile unit 40 goes
unanswered, in accordance with the present invention.
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While the best mode for carrying out the
invention has been described in detail, those familiar
with the art to which this invention relates will
recognize various alternative designs and embodiments
for practicing the invention as defined by the following
claims.
