Title: Wireless mobile call location and delivery for non-geographic numbers using a wireline SSP+SCP/wireless HLR interface
Abstract: A system and method is provided for establishing a call to a wireless directory number (982) which is either a non-geographic directory number or a non-dialable directory number. A call is initiated from a wireless telephone (155) to a geographic-based local access directory number (994, 996). An originating switching node (810) recognizes the local access directory number (994, 996) as an AIN trigger, and thereafter identifies a signaling node (820) that is associated with the dialed local access DN (994, 996). The signaling node (820) sends a location request that includes the local access DN (994, 996) to an HLR (130). The HLR (130) obtains the wireless DN (982) from an internal database (990) in which the wireless DN (982) is associated with the local access DN (994, 996). The HLR (130) utilizes the wireless DN (982) to receive a temporary local directory number (TLDN) from visitor location register (140). The HLR (130) associates the TLDN with the local access DN (994, 996) and subsequently forwards the TLDN to the signaling node (820), which in turn relays the TLDN to the originating switching node (810). The call connection is thereafter established directly from the originating switching node in the end office to a visited cellular switch using the TLDN.
Patent Number: 6,909,900 Issued on 06/21/2005 to Howe
| Inventors:
|
Howe; Walter Wesley (Alpharetta, GA)
|
| Assignee:
|
GTE Wireless Service Corporation (New York, NY)
|
| Appl. No.:
|
577329 |
| Filed:
|
May 24, 2000 |
| Current U.S. Class: |
455/445; 455/432.1; 455/432.2; 455/432.3 |
| Intern'l Class: |
H04Q 007/20 |
| Field of Search: |
455/445,432.1,432.2,432.3,433,403
379/220,207,220.1
|
References Cited [Referenced By]
U.S. Patent Documents
Primary Examiner: Corsaro; Nick
Assistant Examiner: Gantt; Alan T.
Attorney, Agent or Firm: Suchtya, Esq.; Leonard C., Wall, Esq.; Joel, Meschkow & Gresham, P.L.C.
Parent Case Text
RELATED APPLICATIONS
This is a continuation-in-part of U.S. patent application Ser. No. 09/487,844,
filed 19 Jan. 2000 now U.S. Pat. No. 6,757,538, which is a continuation-in-part
of U.S. patent application Ser. No. 09/340,508, filed 1 Jul. 1999 now U.S. Pat.
No. 6,487,412, each assigned to the common assignee of the present invention.
Claims
1. A method for establishing a call to a wireless directory number (DN) associated
with a wireless mobile station, said wireless DN being one of a non-geographic
DN and a non-dialable DN, said method comprising:
receiving a local access DN at an originating switch node, wherein the received
local access DN is compared with information within a trigger table to invoke a
trigger;
identifying a signaling node associated with said local access DN, wherein invoking
the trigger initiates the identifying;
obtaining, from a database residing at a home location register, said wireless
non-geographic or non-dialable DN associated with said local access DN;
utilizing said wireless DN to determine a route that includes said originating
switching node and a visited switching node serving said wireless DN; and
establishing a connection to said wireless mobile station via said determined
route.
2. A method as claimed in claim 1 wherein said local access DN is a geographic
DN maintained at said originating switching node.
3. A method as claimed in claim 2 further comprising associating said geographic
DN with said wireless DN in said database residing at said home location register
prior to said receiving operation.
4. A method for establishing a call to a wireless directory number (DN) associated
with a wireless mobile station, said wireless DN being one of a non-geographic
DN and a non-dialable DN, said method comprising:
establishing a second local access DN maintained at a second originating switching
node;
associating each of a first local access DN and said second local access DN with
said wireless DN in a database at a home location register;
receiving said first local access DN at a first originating switching node, said
first local access DN being maintained at said first originating switching node;
identifying a signaling node associated with said first local access DN;
obtaining, from said database residing at said home location register, said wireless
DN associated with said first local access DN;
utilizing said wireless DN to determine a route that includes said first originating
switching node and a visited switching node serving said wireless DN; and
establishing a connection to said wireless mobile station via said determined
route.
5. A method as claimed in claim 1 wherein said originating switching node includes
an Advanced Intelligent Network (AIN)-capable Service Switching Point (SSP) and
the signaling node comprises an AIN-capable Service Control Point (SCP).
6. A method as claimed in claim 1 wherein said identifying operation comprises
invoking a trigger at said originating switching node indexed as a function of
said local access DN.
7. A method as claimed in claim 1 further comprising:
transmitting, in response to said identifying operation, a route request from
said originating switching node to said signaling node that includes said local
access DN; and
sending a location request to said home location register that includes said
local access DN.
8. A method as claimed in claim 1 wherein said obtaining operation comprises:
receiving, at said home location register, a location request from said signaling
node that includes said local access DN; and
accessing said database to obtain said wireless DN associated with said local
access DN.
9. A method as claimed in claim 1 further comprising sending, in response to
said obtaining operation, a routing request that includes said wireless DN to a
visitor location register with which said wireless mobile station was last registered.
10. A method for establishing a call to a wireless directory number (DN) associated
with a wireless mobile station, said wireless DN being one of a non-geographic
DN and a non-dialable DN, said method comprising:
receiving a local access DN at an originating switching node;
identifying a signaling node associated with said local access DN;
obtaining, from a database residing at a home location register, said wireless
DN associated with said first local access DN;
utilizing said wireless DN to determine a route that includes said originating
switching node and a visited switching node serving said wireless DN, said utilizing
operation including:
sending, in response to said obtaining operation, a routing request that includes
said wireless DN to a visitor location register with which said wireless mobile
station was last registered;
receiving, at said home location register, a temporary local directory number
(TLDN) associated with said wireless DN in response to said routing request; and
employing said local access DN to forward said received TLDN to said originating
switching node;
establishing a connection to said wireless mobile station via said determined
route.
11. A method as claimed in claim 10 wherein said employing operation comprises:
obtaining, from said database, said local access DN associated with said wireless
DN;
associating said local access DN with said TLDN;
forwarding said TLDN associated with said local access DN to said signaling node;
and
relaying said TLDN associated with said local access DN from said signaling node
to said originating switching node.
12. A telecommunications network comprising:
an originating switching node configured to determine when a local access directory
number (DN) associated with a wireless mobile station has been received and to
generate a routing request that includes said local access DN;
a signaling node in communication with said originating switching node, said
signaling node being configured to send a location request that includes said local
access DN in response to receipt of said routing request;
a home location register in communication with said signaling node, said home
location register including a database having a wireless DN associated with said
local access DN, said wireless DN being one of a non-geographic DN and a non-dialable
DN, said home location register being configured to access said database to obtain
said wireless DN and utilize said wireless DN to obtain a temporary local directory
number (TLDN) allocated to said wireless mobile station; and
a visited switching node serving said wireless DN, wherein said originating switching
node is operative to establish a connection to said wireless mobile station using
said TLDN via a route that includes said originating switching node and said visited
switching node.
13. A network as claimed in claim 12 wherein said local access DN is a geographic
DN maintained at said originating switching node.
14. A network as claimed in claim 12 wherein said originating switching node
includes an Advanced Intelligent Network (AIN)-capable Service Switching Point.
15. A network as claimed in claim 12 wherein said originating switching node
includes a trigger for identifying a call destined to said wireless DN.
16. A network as claimed in claim 15 wherein said trigger includes an index and
an identifier identifying said signaling node.
17. A network as claimed in claim 12 wherein said signaling node includes an
Advanced Intelligent Network (AIN)-capable Service Control Point.
18. A network as claimed in claim 12 wherein said home location register is further
configured to receive said TLDN from a visitor location register (VLR) with which
said wireless mobile station was last registered, said TLDN being associated with
said wireless DN, and said home location register is further configured to forward
said TLDN to said signaling node utilizing said local access DN.
19. In a telecommunications network having an originating switching node, a signaling
node, a visitor location register, and a visited switching node, a home location
register system for determining a route for a call to a wireless directory number
(DN) associated with a wireless mobile station, said wireless DN being one of a
non-geographic DN and a non-dialable DN, and said route including said originating
switching node and said visited switching node serving said wireless DN, said system comprising:
a processor;
a database, in communication with said processor, in which said wireless DN is
associated with each of a first and a second local access DN, said first local
access DN being maintained at a first originating switching node and said second
local access DN being maintained at a second originating switching node;
a computer-readable storage medium; and
executable code recorded on said computer-readable storage medium for instructing
said processor to perform operations comprising:
receiving a location request from said signaling node that includes one of said
first and second local access DNs;
accessing said database to obtain said wireless DN associated with said one of
said first and second local access DNs;
sending a routing request that includes said wireless DN to said visitor location
register with which said wireless mobile station was last registered;
receiving a temporary local directory number (TLDN) associated with said wireless
DN in response to said routing request; and
employing said local access DN to forward said received TLDN to said signaling
node.
20. A home location register system as claimed in claim 19 wherein said executable
code instructs said processor to perform further operations comprising:
obtaining from said database, in response to said receiving operation, said one
of said first and second local access DNs associated with said wireless DN;
associating said one of said first and second local access DNs with said TLDN;
and
forwarding said TLDN associated with said one of said first and second local
access DNs to said signaling node, said TLDN being used to establish a connection
to said wireless mobile station via said route.
21. A method for establishing a call to a wireless directory number (DN) associated
with a wireless mobile station, said wireless DN being one of a non-geographic
DN and a non-dialable DN, said method comprising:
receiving a local access DN at an originating switching node, wherein the received
local access DN is compared with information within a trigger table to invoke a
trigger;
identifying a signaling node associated with said local access DN, wherein invoking
the trigger initiates the identifying;
obtaining, from a database residing at a home location register, said wireless
non-geographic or non-dialable DN associated with said local access DN;
utilizing said wireless DN to identify a visited switching node serving said
wireless DN;
determining a route that includes said originating switching node and said visited
switching node; and
establishing a connection to said wireless mobile station via said determined
route.
22. A method as claimed in claim 21 wherein said local access DN is a geographic
DN maintained at said originating switching node.
23. A method as claimed in claim 22 further comprising associating said geographic
DN with said wireless DN in said database residing at said home location register
prior to said receiving operation.
24. A method as claimed in claim 21 wherein said local access DN is a first local
access DN, said originating switching node is a first originating switching node,
and said method further comprises:
establishing a second local access DN maintained at a second originating switching
node; and
associating each of said first local access DN and said second local access DN
with said wireless DN in said database at said location register prior to said
receiving operation.
25. A method as claimed in claim 21 wherein said identifying operation comprises
invoking a trigger at said originating switching node indexed as a function of
said local access DN.
26. A method as claimed in claim 21 further comprising:
transmitting, in response to said identifying operation, a route request from
said originating switching node to said signaling node that includes said local
access DN; and
sending, from said signaling node, a location request to said home location register
that includes said local access DN.
27. A method as claimed in claim 26 wherein said obtaining operation comprises:
receiving, at said home location register, said location request from said signaling
node; and
accessing said database to obtain said wireless DN associated with said local
access DN.
28. A method as claimed in claim 21 further comprising sending, in response to
said obtaining operation, a routing request that includes said wireless DN to a
visitor location register with which said wireless mobile station was last registered.
29. A method as claimed in claim 28 further comprising:
receiving, at said home location register, a temporary local directory number
(TLDN) associated with said wireless DN in response to said routing request; and
employing said local access DN to forward said received TLDN to said originating
switching node.
30. A method as claimed in claim 28 wherein said employing operation comprises:
obtaining, from said database, said local access DN associated with said wireless
DN;
associating said local access DN with said TLDN;
forwarding said TLDN associated with said local access DN to said signaling node;
and
relaying said TLDN associated with said local access DN from said signaling node
to said originating switching node.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to telecommunication networks and, more particularly,
to a method and system for routing calls directed to non-geographic wireless directory
numbers in a telecommunications network.
2. Background of the Art
In known telecommunications networks, a wireline telephone number or directory
number (DN) is associated with a fixed geographic location and is served by a single
wireline switch. In a wireless network, however, a wireless DN is associated with
multiple geographic locations and is served by any one of a number of wireless
switches depending on the specific geographic location of the associated mobile
wireless device (hereinafter mobile wireless station or wireless station) at the
time a call is made. This portability of a wireless DN is one of the basic attributes
of wireless telephony, and is often referred to as "roaming".
In the present implementation of wireless networks, each mobile directory number
is associated by both the wireless and wireline networks with a specific geographic
home switch location. The home switch location includes a physical connectivity
matrix and a stored program control section that houses the logic and algorithms
necessary to control the connectivity. Associated with wireless switches is a collection
of Radio Frequency (RF) channels, aggregated in multiple physical locations called
cell sites across a specific area corresponding to a serving market, and variously
known in the United States under the designations MSA, RSA, MTA, and BTA, depending
on the FCC license.
A pair of entities known as a home location register (HLR) and visitor location
register (VLR) in a telecommunications network provide seamless roaming or call
delivery when a call is placed to or from a wireless DN. A home location register
is associated with a home wireless switch where a wireless DN resides (i.e., the
wireless switch to which all incoming wireline-originated calls to the wireless
DN are directed). A mobile wireless station is located within its home area when
the wireless station can directly communicate with its associated home wireless
switch (i.e., located in the area covered by the home wireless switch).
A visitor location register is associated with a wireless switch currently serving
as a wireless station that is outside of its home area. A wireless station is outside
of its home area (or roams) when the wireless station cannot directly communicate
with the home wireless switch, and instead communicates with another wireless switch,
which is referred to as a visited wireless switch.
Typically, when the VLR and HLR are physically in the same location, the
mobile wireless station is "Home" and is not roaming. When the VLR and the HLR
are not in the same location and specialized protocols are not implemented to make
the wireless station act as if it were "Home", then the wireless station is "roaming".
Phone calls from a land-based terminal or station to a mobile wireless station
can be completed while roaming only by a carefully orchestrated set of interactions
between the HLR and VLR, all of which are described and defined by ANSI-41. ANSI-41
defines the HLR as a logically and possibly physically separate device from the
actual switching matrix underlying the RF portion of the wireless network for the
home location for the mobile wireless station. Similarly, the VLR is defined as
a logically and possibly physically separate device from the actual switching matrix
underlying the RF portion of the wireless network from which a mobile wireless
station is currently being served. This physical separation, together with the
Signaling System Seven (SS7) and the associate messages and protocols, are existing
underlying components utilized by the invention.
One problem with known telecommunication networks is that two connections must
be established when a call is placed to a wireless DN whose associated wireless
station is outside of its home area. In such instances, the telecommunications
network first establishes a connection to the home wireless switch associated with
the wireless DN. That is, in the existing art, the wireless station call is first
routed from the serving wireless switch to the home wireless switch (the HLR location),
possibly by way of additional local or Inter-Exchange Carrier (IXC) switches. The
home wireless switch then establishes a second connection to a visited wireless
switch that currently serves the wireless DN. In particular, the HLR interacts
with the VLR to obtain a Temporary Local Directory Number (TLDN) from the allocations
made for the physical location of the visited wireless switch serving the wireless
station. The wireless switch containing the HLR routes the call via the public
switched telephone network (PSTN) to the wireless switch containing the VLR, which
then establishes the necessary wireless RF connection to the mobile wireless station.
Thus, two separate PSTN connections must be made to complete a single land-to-mobile
call while roaming.
As an illustration, FIG. 1 shows a block diagram of a conventional telecommunications
network
100. Telecommunications network
100 comprises a wireless
switch
110, a home wireless switch
120, a home location register
130, a signal transfer point (STP)
135, a visitor location register
140, a visited wireless switch
150, a wireline telephone
155,
a cell site including antenna
170, and a wireless station
175.
Typically, a wireline subscriber using telephone
155 initiates
a call request
180a by dialing the wireless DN associated with wireless
station
175. When wireline switch
110 receives call request
180a,
wireline switch
110 establishes a first connection
180b via
a Public Switched Telephone Network PSTN)
160 to home wireless switch
120,
which is the home switch associated with the dialed DN.
Home wireless switch
120 sends an ANSI-41 RouteRequest message
180c
to its associated home location register
130, requesting the current
location of the wireless station
175. The text of "Interim Standard (IS)
41", Revision D, has been adopted to become the ANSI-41 standard. The IS-41, Rev.
D, standard is described in "Radio Telecommunications Intersystem Operations,"
ANSI/TIA/EIA/41-D-1997, which is incorporated herein by reference. The ANSI-41
Standard describes the communication protocol between home wireless switch
120,
home location register
130, visitor location register
140, and visited
wireless switch
150 in telecommunications network
100. It should
be understood that although the ANSI-41 standard is referred to herein, the features
and capabilities of IS-41 Revision A have been found sufficient to enable the present invention.
If wireless station
175 is outside of its home area, as shown in FIG.
1,
home location register
130 then identifies the visitor location register
with which wireless station
175 was last registered, for example, visitor
location register
140, and sends an ANSI-41 RouteRequest message
180d
via STP
135 to visitor location register
140.
Visitor location register
140 forwards RouteRequest message
180d
to its associated visited wireless switch
150, requesting a route to
wireless station
175. Visited wireless switch
150 computes a temporary
local directory number (TLDN), which can be used in establishing incoming calls
to wireless station
175. Visited wireless switch
150 then returns
the TLDN to visitor location register
140 in an ANSI-41 message
180e.
Visitor location register
140 then sends, via STP
135, to home
location register
130, an ANSI-41 RouteRequest response message
180f
that includes the TLDN.
Home location register
130 forwards RouteRequest response message
180f
to home wireless switch
120. Using the TLDN in RouteRequest response
message
180f, home wireless switch
130 then establishes a
second connection
180g to visited wireless switch
150, which
sends a ring signal to wireless station
175. Thus, to establish a call between
telephone
155 and wireless station
175 when wireless station
175
is outside of its home area, telecommunications network
100 must establish
two separate connections
180b and
180g.
Another problem with conventional methods of routing land-to-mobile calls
is that they are dependent on a known geographic "home" for the wireless DN in
the home wireless switch. That is, certain directory numbers cannot be used as
wireless DN's using the conventional approach shown in FIG.
1. These directory
numbers include non-geographic numbers (e.g., NANP directory numbers to which no
geographic territory has been assigned) and/or non-dialable numbers (e.g., directory
numbers not provided for under the NANP). This unavailability is because such numbers
are not routable under conventional approaches, inasmuch as they have no geographic
endpoint (i.e., there is no "home" wireless switch for a non-geographic directory
numbers). This unavailability reduces the capacity of the telecommunications network,
as well as its efficiency.
In addition, another problem arises with conventional methods of routing land-to-mobile
calls. With conventional methods, a wireless mobile station is assigned to a single
home area. Accordingly, land-to-mobile calls that are originated outside of the
home area are long distance calls. These long distance calls are subject to higher
billing rates, which may discourage potential callers from dialing the wireless
mobile station. In a scenario in which these potential callers are business associates
or clients who are located in regions outside of the subscriber's home area, the
higher billing rates may undesirably inhibit growth of the subscriber's client
base or may result in a loss of some business associates or clients because the
business associates or clients do not wish to place long distance calls.
Accordingly, there is a need for a method and system for establishing
land-to-mobile calls that minimizes or eliminates one or more problems as set forth above.
SUMMARY OF THE INVENTION
An advantage of the present invention is that a method and a system are provided
that reduce the number of connections that must be established in a telecommunications
network when making a call from a land telecommunications terminal to a wireless
mobile station.
Another advantage of the present invention is that the method and system
increase network capacity and efficiency by enabling use of non-geographic and
non-dialable directory numbers for wireless stations that would otherwise go unused.
It is yet another advantage of the present invention that the method and system
allow a wireless mobile station to have multiple local directory numbers each associated
with a different geographic location.
The above and other advantages of the present invention are carried out in one
form by a method for establishing a call to a wireless directory number (DN) associated
with a wireless mobile station, the wireless DN being one of a non-geographic DN
and a non-dialable DN. The method calls for receiving a local access DN at an originating
switching node and identifying a signaling node associated with the local access
DN. The method further calls for obtaining, from a database residing at a home
location register, the wireless DN associated with the local access DN, utilizing
the wireless DN to determine a route that includes the originating switching node
and a visited switching node serving the wireless DN, and establishing a connection
to the wireless mobile station via the determined route.
The above and other advantages of the present invention are carried out in another
form by a telecommunications network which includes an originating switching node
configured to determine when a local access directory number (DN) associated with
a wireless mobile station has been received and to generate a routing request that
includes the local access DN. A signaling node is in communication with the originating
switching node. The signaling node is configured to send a location request that
includes the local access DN in response to receipt of the routing request. A home
location register, in communication with the signaling node, includes a database
having a wireless DN associated with the local access DN, the wireless DN being
one of a non-geographic DN and a non-dialable DN. The home location register is
configured to access the database to obtain the wireless DN and utilize the wireless
DN to obtain a temporary local directory number (TLDN) allocated to the wireless
mobile station. The network further includes a visited switching node serving the
wireless DN. The originating switching node is operative to establish a connection
to the wireless mobile station using the TLDN via a route that includes the originating
switching node and the visited switching node.
This summary and the following description of the invention should not restrict
the scope of the claimed invention. Both provide examples and explanations to enable
others to practice the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which form part of the description of the invention,
show several embodiments of the invention, and together with the description, explain
the principles of the invention.
In the Figures:
FIG. 1 is a block diagram of a conventional telecommunications network;
FIG. 2 is a block diagram of a telecommunications network in accordance with
methods and systems consistent with the present invention;
FIG. 3 is a block diagram of wireline switch in a telecommunications network
in accordance with methods and systems consistent with the present invention;
FIG. 4 is a block diagram of a trigger table in a wireline switch in accordance
with methods and systems consistent with the present invention;
FIG. 5 is a block diagram of a signaling node in a telecommunications network
in accordance with methods and systems consistent with the present invention;
FIG. 6 is a flow chart of the steps performed by a call processing module in
a wireline switch in accordance with methods and systems consistent with the present invention;
FIG. 7 is a flow chart of the steps performed by a call routing module in a
signaling node in accordance with methods and systems consistent with the present invention;
FIG. 8 is a block diagram of a telecommunications network in accordance with
a further two-stage dialing embodiment consistent with the present invention; and
FIG. 9 is a block diagram of a home location register in accordance with an
alternative single-stage dialing embodiment consistent with the present invention.
DETAILED DESCRIPTION
The following description of embodiments of this invention refers to the accompanying
drawings. Where appropriate, the same reference numbers in different drawings refer
to the same or similar elements.
Methods and systems consistent with the present invention establish a single
connection in a telecommunications network when connecting calls to wireless directory
numbers (DNs) regardless of whether the associated wireless stations are within
or outside of their respective home areas. In one embodiment, when a call is directed
to a wireless DN, a wireline switch in the network identifies a signaling node
associated with the wireless DN and sends the identified signaling node a request
for a route to the wireless DN. If the wireless station associated with wireless
DN is outside of its home area and is served by a visited node in the network,
the signaling node determines a route that excludes the home node associated with
the wireless DN and returns a temporary local directory number (TLDN) to the wireline
switch. Using the TLDN, the wireline switch establishes a connection to the visited
node, which sends a ring signal to the associated wireless station.
FIG. 2 is a block diagram of a telecommunications network
200 in accordance
with methods and systems consistent with the present invention. As shown, telecommunications
network
200 comprises a wireline switch
210, a signaling node
220,
signal transfer points (STPs)
135,
225 and
235, home wireless
switch
120, home location register
130, visitor location register
140, visited wireless switch
150, a wireline station or telephone
155, cell site including antenna
170, and wireless station
175.
Wireline switch
210 connects to telephone
155 having an associated
directory number, PSTN network
160, and STP
225. Wireline switch
210 may include, for example, a 5ESS™, DMS-100™ (or DMS-200™),
GTD-5™, or an EWSD™ switching system manufactured by Lucent Technologies,
Inc., Nortel Networks Corporation, AGCS, and Siemens, respectively. As explained
below in detail, wireline switch
210 is configured to communicate with signaling
node
220 when establishing incoming calls to wireless DNs, for example the
wireless DN associated with wireless station
175.
Signaling node
220 interfaces home location register
130
via STP
235, which routes signaling messages in telecommunications network
200. Alternatively, signaling node
220 may interface with home location
register
130 via a signaling network such as, a Signaling System 7 (SS7)
network or an Internet Protocol (IP) network. Signaling node
220 may include
a Service Control Point (SCP) such as, AI-NET™, Integrated Service Control
Point (ISCP™) or Service Builder™ equipment/software manufactured
or provided by Lucent Technologies, Inc., Telcordia Technologies, Inc., and Nortel
Networks Corporation, respectively.
Home location register
130 interfaces via STP
235 with signaling
node
220 and via STP
135 with visitor location register
140.
Home location register
130 stores information about wireless subscribers
in telecommunications network
200 such as, the current location of a wireless
station associated with a subscriber, billing information, and services that the
wireless subscriber is authorized to use. Visitor location register
140
stores information about the current location of a wireless station when a wireless
station is activated outside of its home area. For example, in telecommunications
network
200, wireless station
175 is within its home area when wireless
station
175 directly communicates with home switch
120. However,
wireless station
175 is outside of its home area when wireless station
175
cannot directly communicate with home wireless switch
120 and instead communicates
with visited wireless switch
150. STPs
135,
225, and
235
route signaling messages such as, Advanced Intelligent Network (AIN), IS-41, ANSI-41,
and SS7 messages in telecommunications network
200. Each STP
135,
225, and
235 may be an adjunct to a wireline or a wireless switch
in telecommunications network
200.
Call flow processing in telecommunications network
200 will be explained
in detail below with reference to FIGS. 6 and 7.
FIG. 3 is a block diagram of wireline switch
210 in accordance with methods
and systems consistent with the present invention. As shown, wireline switch
210
comprises a processor
300, which connects via a bus
310 to a memory
320, a secondary storage
330, a peripheral interface module
340,
a signaling interface module
350, an input terminal
360, and an output
terminal
370.
Memory
320 includes a call processing
380, an operating system
382, and a trigger table
384, all of which are executed by processor
300. Call processing
380 includes software and data for establishing,
maintaining, and terminating calls between subscribers. Operating system
382
includes software and data for non-switching functions, which include, for example,
task scheduling and processor interrupt handling. As explained below in detail,
trigger table
384 includes entries that are used to intercept calls destined
to wireless DNs and to identify the associated signaling nodes for routing calls
to wireless DNs without establishing connections to the home wireless switches
associated with the wireless DNs.
Peripheral interface module
340 interfaces with trunks that connect
wireline switch
210 to PSTN network
160. The trunks carry calls,
which may include, voice, data, and video, established in telecommunications network
200.
Signaling interface module
350 transmits to and receives from STP
225 signaling information such as, AIN, IS-41, and ANSI-41 messages. For
example, signaling interface module
350 converts signaling information generated
by call processing
380 into AIN, IS-41 or ANSI-41 messages and transmits
the messages to STP
225. Likewise, signaling interface module
350
receives AIN, IS-41 or ANSI-41 messages from STP
225 and converts the messages
into an internal format for processing by call processing
380.
Secondary storage
330 includes a computer readable medium such as
a disk drive and a tape drive. From the tape drive, software and data may be loaded
onto the disk drive, which can then be copied into memory
320. Similarly,
software and data in memory
320 may be copied onto the disk drive, which
can then be loaded onto the tape drive.
Input terminal
360 may include an input device such as, a keyboard,
and output terminal
370 may include a display device.
FIG. 4 is a block diagram of trigger table
384 in accordance with methods
and systems consistent with the present invention. Trigger table
384 includes
N predetermined triggers shown as entries
4001-
400N,
where each entry includes an index field and an identifier field. For example,
entry
400N may include an index field
410N,
and an identifier field
420N. In an embodiment where triggers
4001-
400N are Public Office Dialing Plan (PODP)
triggers, an index field may include a 3, 6, or 10 digit string such as, an area
code, an area code and an office code, or a DN. PODP triggers are described in
AIN 0.1 standards TR-NWT-001284: Advanced Intelligent Network (AIN) 0.1 Switching
System Generic Requirements, Issue 1 (August 1992) and TR-NWT-001285: Advanced
Intelligent Network (AIN) 0.1 Service Control Point (SCP) Application Protocol
Interface Requirements, Issue 1 (August 1992), both of which are incorporated herein
by reference.
Alternatively, in an embodiment where triggers
4001-
400N
are Specific Digit String (SDS) triggers, an index may include any sequence of
digits. SDS triggers are described in AIN 0.2 standards GR-1298-CORE: AIN SSP,
AINGR: Switching Systems (A Module Of AINGR, FR-15), Issue 4 (September 97) and
GR-1299-CORE: AINGR: Switch-Service Control Point (SCP)/Adjunct Interface (A Module
Of AINGR, FR-15), Issue 4 (September 97), both of which are incorporated herein
by reference.
An identifier field includes a numeric string that identifies a signaling node
associated with any wireless DN whose area code, area code and office code, or
DN matches the associated index field in trigger table
384. For example,
trigger table
384 may be configured to include a trigger entry
400N
where index
410N includes the area code associated with the DN
assigned to wireless station
175 and identifier
420N includes
a translation type/global title address (TT/GTA) associated with signaling node
220. The TT/GTA may then be communicated to STP
225 for determining
a point code associated with signaling node
220. Alternatively, identifier
420N may include a point code associated with signaling node
220, which may be used by wireline switch
210 to directly identify
signaling node
220.
FIG. 5 is a block diagram of signaling node
220 in accordance with methods
and systems consistent with the present invention. Signaling node
220 comprises
a processor
500, which connects via a bus
510 to a memory
520,
a secondary storage
530, a signaling interface module
540, an input
terminal
550, and an output terminal
560.
Memory
520 includes a call routing
570 and an operating system
572. Call routing
570 includes software and data for communicating
with home location register
130 and other databases (not shown) such as,
a Call Management Services Database (CMSDB), a Line Information Database (LIDB),
and a Business Service Database (BSDB) in telecommunications network
200
when determining a route to a wireless DN such as, the wireless DN associated with
wireless station
175.
Signaling interface module
540 transmits to and receives from STPs
225 and
235 signaling information such as, AIN, IS-41, and ANSI-41
messages. For example, signaling interface module
540 converts signaling
information generated by call routing
570 into AIN, IS-41 or ANSI-41 messages
and transmits the messages to STPs
225 and
235. Likewise, signaling
interface module
540 receives AIN, IS-41 or ANSI-41 messages from STPs
225
and
235 and converts the messages into an internal format for processing
by call routing
570.
Secondary storage
530 includes a computer readable medium such as
a disk drive and a tape drive. From the tape drive, software and data may be loaded
onto the disk drive, which can then be copied into memory
520. Similarly,
software and data in memory
520 may be copied onto the disk drive, which
can then be loaded onto the tape drive.
Input terminal
550 may include an input device such as, a keyboard,
and output terminal
560 may include a display device.
FIG. 6 is a flow chart of the steps performed by call processing
380
in wireline switch
210 when a wireline subscriber using telephone
155
originates a call to wireless station
175 in accordance with methods and
systems consistent with the present invention. When the wireline subscriber dials
the DN associated with wireless station
175, wireline switch
210
receives and processes a call request
180a in accordance with call
processing
380 (step
600). Call processing
380 then determines
whether trigger table
384 includes a trigger whose index matches a sequence
of digits in the dialed DN such as, the area code, a combination of the area code
and office code, or any other sequence of digits (step
610).
If call processing
380 determines that trigger table
384 does not
include any triggers with a matching index, call processing
380 continues
normal call processing (step
620). If trigger table
384 includes
a trigger with a matching index, call processing
380 suspends normal call
processing and invokes the trigger to identify a signaling node, for example signaling
node
220, associated with the dialed DN (step
630).
In one embodiment, the invoked trigger includes the TT/GTA associated with signaling
node
220. In this embodiment, call processing
380 then sends an AIN
info-analyze message
230a via STP
225 to signaling node
220,
requesting a route for establishing a call to the dialed DN (step
640).
Info_analyze message
230a includes as its parameters the DN associated
with the calling telephone
155 and the dialed DN associated with wireless
station
175.
For example, call processing
380 may send info_analyze message
230a
to STP
225 using a Signaling Connection Control Part (SCCP) message,
which includes the TT/GTA associated with signaling node
220. Using the
TT/GTA, STP
225 then determines from its internal tables the point code
associated with signaling node
220 and forwards info_analyze message
230a
to signaling node
220.
Alternatively, in another embodiment, the invoked trigger may include
the point code associated with signaling node
220. In this embodiment, call
processing
380 may send an AIN info_analyze message
230a directly
to signaling node
220.
In response to info_analyze message
230a, if wireless station
175
is within its home area (not shown), call processing
380 receives from signaling
node
220 and AIN continue response message. Call processing
380 then
resumes normal call processing, and using the dialed DN, establishes a connection
to home wireless switch
120, which sends a ring signal to wireless station
175.
However, if wireless station
175 is outside of its home area as shown
in FIG. 2, call processing
380 receives from signaling node
220 an
analyze_route message
230e, which includes a temporary local directory
number (TLDN) (step
650). Call processing
380 uses the TLDN to establish
a connection
230f to visited wireless switch
150, which sends
a ring signal to wireless station
175 (step
660).
Accordingly, a single connection
230f is established to
a single wireless switch in telecommunications network
200 when establishing
a call to wireless station
175 regardless of whether wireless station
175
is within or outside of its home area. In other words, when wireless station
175
is within its home area, a single connection is established to home wireless switch
120 as explained above. Likewise, when wireless station
175 is outside
of its home area as shown in FIG. 2, a single connection is established to visited
wireless switch
150.
FIG. 7 is a flow chart of the steps performed by call routing
570 in
signaling node
220 when signaling node
220 receives from wireline
switch
210 a request for routing a call to a dialed DN associated with wireless
station
175 in accordance with methods and systems consistent with the present
invention. When signaling node
220 receives info analyze message
230a
from wireline switch
210 (step
700), call routing
570
identifies a home location register, for example home location register
130,
associated with the dialed DN (step
710).
Call routing
570 sends an ANSI-41 LocationRequest message
230b
via STP
235 to the identified home location register
130, requesting
a route for establishing a call to the dialed DN (step
720). In response
to LocationRequest message
230b, if wireless station
175 is
within its home area, home location register
130 sends to signaling node
220 via STP
235 a LocationRequest response message that includes
the dialed DN. Based on the dialed DN value in the LocationRequest response message,
call routing
570 determines that wireless station
175 is within its
home area and sends via STP
225 an AIN continue response message to wireline
switch
210. Using the dialed DN, wireline switch
210 then establishes
a connection to home wireless switch
120, which sends a ring signal to wireless
station
175.
However, if wireless station
175 is outside of its home area as shown
in FIG. 2, home location register
130 identifies the visitor location register,
for example, visitor location register
140, with which wireless station
175 last registered, and sends an ANSI-41 RouteRequest message
180d
via STP
135 to the identified visitor location register
140.
Visitor location register
140 then forwards RouteRequest message
180d
to its associated visited wireless switch
150, requesting a route to
wireless station
175.
Visited wireless switch
150 computes a temporary local directory number
(TLDN), which can be used for establishing incoming calls to wireless station
175.
Visited wireless switch
150 then returns the TLDN to visitor location register
140 in an ANSI-41 message
180e. Visitor location register
140 then sends via STP
135 to home location register
130 an
ANSI-41 RouteRequest response message
180f that includes the TLDN.
When home location register
130 receives RouteRequest response message
180f,
it sends via STP
235 to signaling node
220 an ANSI-41 LocationRequest
response message
230c that includes the TLDN.
When signaling node
220 receives LocationRequest response message
230c
from home location register
130 (step
730), call routing
570
sends analyze_route message
230e via STP
225 to wireline switch
210, providing wireline switch
210 with the TLDN for establishing
a call to wireless station
175 (step
740). Using the TLDN, wireline
switch
210 establishes a connection
230f to visited wireless
switch
150, which sends a ring signal to wireless station
175. Accordingly,
only a single connection
230f is established to a single wireless
switch (i.e., visited wireless switch
150) in telecommunications network
200 when establishing a call to wireless station
175 while wireless
station
175 is outside of its home area.
Two-Stage Dialing
FIG. 8 shows a further embodiment of a telecommunications network
800.
Network
800 provides a system for establishing a call to a wireless directory
number (DN) associated with a wireless mobile station
175 wherein the wireless
DN is either a non-geographic DN or a non-dialable DN.
A non-geographic directory number, in the embodiment shown in FIG. 8, may be a
unique ten-digit number in the same format as a ten-digit North American Numbering
Plan (NANP) number, but which has no geographic territory assigned thereto. These
non-geographic directory numbers will be allocated specifically for wireless mobile purposes.
A non-dialable directory number is a number that is not provided for as an NANP
directory number (e.g., a ten-digit directory number beginning with "011"). The
nomenclature "non-dialable" is used herein to describe those numbers that are not
used by the NANP to indicate numbering plan area (i.e., area code) or central office
code. However, the "non-dialable" directory number may be "dialable" in that it
may be allowed for use as a prefix for dialing to another country, as a prefix
for accessing directory assistance, and so forth.
Administration of non-geographic directory numbers or non-dialable
directory numbers in accordance with the invention may be accomplished on a centralized
basis, for example, as is currently done for toll free (e.g., "800," "888" and
"877") numbers. The meaning of the terms non-geographic directory numbers and non-dialable
directory numbers are the same as would be understood by one of ordinary skill
in the art.
It bears emphasizing that a key disadvantage of conventional networks is that
non-geographic directory numbers have no "home" wireless switching matrix associated
therewith. According to conventional teachings, an HLR with its accompanying home
wireless switch is where calls to wireless directory numbers are first routed.
Non-dialable numbers are not recognized by local switches. Accordingly, non-geographic
and non-dialable directory numbers have been unavailable for use in wireless applications.
The embodiment of FIG. 8, according to the invention, enables use of non-geographic
and/or non-dialable directory numbers for wireless mobile applications by establishing
a novel two-stage dialing process. The caller first dials a preselected geographic-based
access number. Next, dialtone is provided, and digits are collected from the caller
corresponding to the desired wireless DN. The caller may be a person, or, in another
embodiment, may be a modem, programmed to recognize the dialtone so provided and
transmit digits in response thereto. The invention improves network capacity and efficiency.
A description of the embodiment of FIG. 8 begins with telecommunications network
800 including a wireline station such as telephone
155, Public Switched
Telephone Network (PSTN)/Inter-Exchange Carrier (IXC)
160, an originating
switching node
810, a signaling node (SCP)
820, signal transfer point
(STP)
235, Home Location Register (HLR)
130, signal transfer point
(STP)
135, visitor location register (VLR)
140, visited switching
node
150, cell site including antenna
170, and wireless mobile station
175.
HLR
130, VLR
140, visited switching node
150, wireline subscriber
stations
155, PSTN/IXC
160, and cellular site including antenna
170
may each comprise conventional apparatus such as that described above in connection
with network
200.
STPs
135 and
235 may also comprise conventional apparatus known
in the art, as described above.
Originating switching node
810 is located in an end office associated
with the preselected access directory number. Originating switching node
810
may be a local serving switch if wireline subscriber station
155 is served
directly out of that office. Alternatively, and as also shown in FIG. 8, originating
switching node
810 may be accessed from wireline subscriber station
155
through PSTN/IXC
160, which may comprise one or more intermediate offices.
Originating switching node
810 is similar to wireline switch
210
inasmuch as it is configured to communicate, upon occurrence of a trigger event,
with signaling node
820 when establishing connections for incoming calls.
To this extent, the structure of switch
210 illustrated in FIGS. 3 and 4
(and the description associated therewith) applies equally to originating switching
node
810. Originating switching node
810, in a preferred embodiment,
comprises an Advanced Intelligent Network (AIN)-capable Service Switching Point
(SSP), compatible with and at least conforming to AIN release 0.1 (switching node
810 is hereinafter referred to as "SSP
810"). As with switch
210,
SSP
810 executes a formal call model, which includes various trigger conditions,
as described above with respect to network
200. In accordance with the present
invention, SSP
810 is configured with a trigger so as to detect when the
preselected geographic access directory number has been dialed, and to thereafter
suspend call processing while querying signaling node
820 for further instructions.
The present invention is described in terms of calls originating from a wireline
telephone connected to wireline originating switch. However the present invention
may be adapted for use at wireless originating switches capable of transmitting
and receiving signaling information such as AIN, IS-41, and ANSI-41 messages. As
such, calls may originate from a wireless station associated with a wireless originating
switch that executes a formal call model which includes the various trigger conditions
described herein.
Signaling node
820 is similar to signaling node
220. Therefore,
the structure of node
220 illustrated in FIG. 5 (and the description associated
therewith) applies equally to signaling node
820. Signaling node
820
interfaces to HLR
130 via network
800<
