US20080064409A1 - Wireless direct routing system - Google Patents

Abstract

A method for routing a communication to a wireless device through a wireline network includes storing a registration of a wireless device with a first mobile switching center, in response to the wireless device registering with the first mobile switching center. A request for the registration of the wireless device with the first mobile switching center is received. The registration of the wireless device with the first mobile switching center is provided. The communication is routed to the wireless device from a node in the wireline network when the node in the wireline network is provided with routing instructions from a controller for the wireline network in response to the controller identifying the registration of the wireless device with the first mobile switching center.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• This application is a continuation Application of pending U.S. patent application Ser. No. 10/638,318, filed on Aug. 12, 2003, the disclosure of which is expressly incorporated herein by reference in its entirety.
1. FIELD OF THE INVENTION
• The present invention relates to the field of telecommunications. More particularly, the present invention relates to routing of calls to a wireless network through an advanced intelligent network (AIN) network.
2. ACRONYMS
• The written description contains acronyms that refer to various telecommunications services, components and techniques, as well as features relating to the present invention. Although some of these acronyms are known, use of these acronyms is not strictly standardized in the art. For purposes of the written description, the acronyms are defined as follows:
• Advanced Intelligent Network (AIN)
• Advanced Mobile Phone Service (AMPS)
• Carrier Advanced Intelligent Network (CAIN)
• Code Division Multiple Access (CDMA)
• Direct Sequence Code Division Multiple Access (DS-CDMA)
• Dual Tone Multi-Frequency (DTMF)
• Electronic Key Telephone System (EKTS)
• Global System for Mobile Communications (GSM)
• Home Location Register (HLR)
• Local Access and Transport Area (LATA)
• Metropolitan Trading Area (MTA)
• Mobile Identification Number (MIN)
• Mobile Switching Center (MSC)
• Mobile Telephone Switching Center (MTSC)
• Personal Digital Assistant (PDA)
• Personal Identification Number (PIN)
• Plain Old Telephone Service (POTS)
• Public Switched Telephone Network (PSTN)
• Service Control Point (SCP)
• Service Switching Point (SSP)
• Signaling System 7 (SS7)
• Signaling Transfer Point (STP)
• Temporary Location Destination Number (TLDN)
• Time Division Multiple Access (TDMA)
• Trunk Group Trigger (TGT)
3. BACKGROUND INFORMATION
• Wireless devices, such as cellular telephones and personal digital assistants (PDA), have enabled mobile users to roam over large geographic areas while maintaining immediate access to telephony services. Wireless communication systems typically provide service to a geographic market area by dividing the area into many smaller areas called cells. Each cell is serviced by a base station, which receives and transmits on predetermined telecommunication radio frequencies, as directed by its associated controller. The cell sites connect to a mobile switching center (MSC), through land lines or other communication links. Each MSC is likewise connected to the public switched telephone network (PSTN), to enable communications between wireline and wireless parties.
• The conventional method of connecting wireless and wireline networks is generally outlined below in reference toFIG. 1. An exemplary call is initiated at thecalling party telephone20 and routed from an originating end office switch, such as a service switching point (SSP)21, to atandem switch24. A host MSC31 receives the call from atandem switch24, deciphers the directory number and queries the home location register (HLR)30, through a signaling transfer point (STP)25, for example, to retrieve data indicating the current status of amobile station35. The data includes the identity of the MSC and/or trunk group at which the mobile station is currently registered based on the location of themobile station35. TheHLR30 is a database relating to mobile stations in the wireless network (e.g., based on the common NPA/NXX and/or carrier), including the mobile stations assigned to the MSC31. When the MSC servicing themobile station35 is not the host MSC31, such as servicing MSC32, the MSC31 routes the call to the servicing MSC32 through a back haul facility. The servicing MSC32 then completes the call to themobile station35 utilizing the appropriate wireless communications network elements, such as the base station servicing the cell in which themobile station35 is located, indicated by abase station33.
• The use of back haul facilities is inefficient and expensive. It increases routing and trunk group administration complexity, as well as traffic load on the MSCs. For example, in addition to handling calls to mobile stations currently located in its geographic area, the host MSC31 must continue to handle all calls to each mobile station that it hosts (e.g., based on the corresponding NPA/NXX), regardless of where the mobile station is located. The present invention overcomes the problems associated with the prior art, as described below.
4. BRIEF DESCRIPTION OF THE DRAWINGS
• The present invention is further described in the detailed description that follows, by reference to the noted drawings by way of non-limiting examples of embodiments of the present invention, in which like reference numerals represent similar parts throughout several views of the drawings, and in which:
• FIG. 1 is a prior art architecture block diagram showing an exemplary conventional telecommunications network, including wireline and wireless networks;
• FIG. 2 is a block diagram showing exemplary architecture of a telecommunications network, including wireline and wireless networks, according to an aspect of the present invention;
• FIG. 3 is an exemplary call flow diagram showing routing of a telephone call to a mobile station registered at a host MSC, according to an aspect of the present invention;
• FIG. 4 is an exemplary call flow diagram showing routing of a telephone call to a mobile station registered at an MSC other than the host MSC, according to an aspect of the present invention;
• FIG. 5 is a logic flowchart of exemplary SCP service logic for routing a telephone call to a mobile station, based on registration status of the mobile station, according to an aspect of the present invention; and
• FIG. 6 is a block diagram showing an exemplary telecommunications network, including wire line and wireless networks in different an Intra-LATA configuration.
5. DETAILED DESCRIPTION OF EMBODIMENTS
• The present invention relates to efficiently routing calls from a wireline network, such as the PSTN, to a mobile station in a wireless network, using AIN capabilities in the PSTN to identify the trunk group associated with a mobile switching center (MSC), or a mobile telephone switching center (MTSC), at which the mobile station is presently registered, to avoid utilizing back haul facilities. The routing includes use of a newly developed AIN trigger, known as a terminating attempt trunk group trigger (TGT), launched by the tandem switch of the trunk group associated with the mobile station's host MSC. Furthermore, the invention relates to routing calls to mobile units roaming outside the local access and transport area (LATA) and/or metropolitan trading area (MTA) of the mobile station's host MSC directly to an interexchange (IXC) switch, in order to access the other LATA and/or MTA, using AIN capabilities in the PSTN.
• In view of the above, the present invention, through one or more of its various aspects and/or embodiments, is presented to accomplish one or more objectives and advantages, such as those noted below.
• An aspect of the present invention provides a method to reduce the number of MSC ports required to process calls and to reduce back haul facilities between the MSCs.
• Another aspect of the present invention provides a method for routing a call to a wireless number, associated with an MSC, through a wireline network. The method includes determining routing data for the call, based on data retrieved from the host MSC, in response to a query initiated by a switch in association with a trunk group of the host MSC. The query may include a trunk group trigger (TGT), launched by the switch, which corresponds to a query including at least the wireless number and identification of the trunk group. The call is routed from the switch to an alternate location when required, without routing through the host MSC. The alternate location may be associated with an alternate number, including a trunk group number of an alternate MSC or an IXC carrier. Also, the routing data may be determined based on a geographic location of a wireless device, corresponding to the wireless number.
• Another aspect of the present invention provides a method for routing a call through a wireline network to a mobile station in a wireless network, which includes at least a host MSC corresponding to a directory number of the mobile device. The method includes suspending the call at a switch associated with a trunk group of the host MSC; receiving a query from the switch, including the directory number; retrieving registration data of the directory number from a database associated with the host MSC, based on at least the directory number; and identifying a servicing MSC based on the registration data. The registration data may include a trunk group number or a routing index of the servicing MSC. The registration data may include location data, indicating a location of the mobile station, such that the method further includes translating the location data into one of a trunk group number and a routing index of the servicing MSC.
• When the servicing MSC is not the host MSC, the call is routed from the switch to the servicing MSC without passing through the host MSC. When the servicing MSC is in a second LATA, different from a first LATA associated with the host MSC, the call is routed from the switch to an interexchange carrier, capable of accessing the second LATA, without passing through the host MSC. When the servicing MSC is in a second MTA, different from a first MTA associated with the host MSC, the call is routed from the switch to an interexchange carrier, capable of accessing the second MTA, without passing through the host MSC. Also, retrieving registration data may include sending an IS-41 protocol query via a signaling network to the database associated with the host MSC, and receiving the registration data via the signaling network in response to the query.
• Another aspect of the present invention provides a method for routing a call to a wireless device through a wireline network, the wireless device having a wireless number associated with a host MSC located in a first LATA, the wireless device being serviced by an alternate MSC located in a second LATA. The method includes determining routing data for the call, based on data retrieved from a location register of the host MSC, in response to a query initiated by a switch, associated with a trunk group of the host MSC, in response to the call. The routing data includes at least identification of an alternate trunk group of the alternate MSC and an interexchange switch of the second LATA. Also, the query may be based on TGT launched by the switch, the query including at least the wireless number and identification of the trunk group. The call is routed from the trunk group switch to an interexchange switch of the first LATA, without routing through the host MSC, in response to the routing data indicating the interexchange switch of the second LATA. The alternate trunk group may be determined based on a geographic location of the wireless device. Further, the routing data may be passed to the first LATA interexchange switch and the second LATA interexchange switch, and the call may be routed from the first LATA interexchange switch to the second LATA interexchange switch, identified by the routing data. The call is then routed from the second LATA interexchange switch to the alternate trunk group, identified by the routing data.
• Another aspect of the present invention provides a system for routing a call through a wireline network to a wireless device in a wireless network, the wireless device having an associated wireless directory number. The system includes a host MSC in the wireless network and a service control point (SCP) in the wireline network. The host MSC is associated with the wireless directory number and includes a location register, which includes registration data identifying a servicing MSC currently associated with the wireless directory number. The servicing MSC is determined by at least a location of the wireless device. The SCP receives a query from a tandem switch associated with a trunk group of the host MSC in response to the call to the wireless device, retrieves the registration data from the location register, and instructs the tandem switch to route the call to the servicing MSC based on the registration data. When the servicing MSC is not the host MSC, the SCP instructs the tandem switch to route the call to the servicing MSC without passing through the host MSC. The query received from the tandem switch may include a trunk group trigger, including at least the wireless directory number.
• The system for routing the call may further include first and second interexchange switches. The first interexchange switch, located in a first LATA, includes the host MSC. The second interexchange switch, located in a second LATA, includes the servicing MSC. The registration data further identifies the second interexchange switch. The SCP accordingly instructs the tandem switch to route the call to the servicing MSC by first routing the call through the first interexchange switch, without passing through the host MSC.
• Another aspect of the present invention provides a system for routing a call, through a PSTN, to a wireless device having an associated directory number. The system includes multiple MSCs, each of which corresponds to a geographic coverage area. The wireless device is assigned to a host MSC of the MSCs based on at least a portion of the directory number. The system further includes at least one location register, which includes registration data identifying one MSCs which corresponds to the geographic coverage area in which the wireless device is currently located. The host MSC retrieves the registration data from the at least one location register and sends the registration data to an SCP in the PSTN, in response to a query from the SCP. The query from the SCP is triggered by the call to the wireless device. The SCP instructs a tandem switch, associated with the host MSC, to route the call to the MSC identified by the registration data, without routing the call through the host MSC, when the MSC is not the host MSC.
• Yet another aspect of the present invention provides computer data signaling, embodied on a propagation medium, that processes a call in a wireless network and a wireline network. The wireless network includes a first MSC associated with a mobile station, and the wireline network includes an SCP and a tandem switch corresponding to a first trunk group of the first MSC. The computer data signaling includes a first query signal, between the tandem switch and the SCP, including at least a trunk group number associated with the first trunk group and a directory number of the mobile station, and a second query signal, between the SCP and the first MSC, including a request for location data of the mobile station. The first MSC retrieves the location data from a database, based on the directory number, and forwards the location data to the SCP. The first query signal may be triggered by a TGT, associated with the first trunk group, when the first tandem switch detects an attempted termination of the call to the directory number through the first MSC. The second query signal may include IS-41 signaling.
• The computer data signaling further includes a routing signal, between the SCP and the tandem switch, including at least one of an identification of a second MSC or a second trunk group of the second MSC, when the location data indicates that the mobile station is positioned in an area serviced by the second MSC. The location data may include a trunk group number associated with the second trunk group. Also, the location data may include a set of coordinates corresponding to the position of the mobile station. The first tandem switch routes the call to the second MSC, without routing the call through the first MSC, in response to the routing signal.
• The various aspects and embodiments of the present invention are described in detail below.
• FIG. 2 illustrates an exemplary telecommunications network of the present invention. The telecommunications network includes a wireline network or PSTN, including anoutside party telephone20, anSSP21 and atandem switch24. Theoutside party telephone20 may be any type of PSTN compatible telephone, including a plain old telephone service (POTS) telephone, or a telephone in a Centrex system, a PBX system or an electronic key telephone system (EKTS). The callingparty telephone20 may also be dual tone multiple frequency (DTMF) capable, although it is not necessary.
• TheSSP21 is an end office switch servicing the callingparty telephone20. TheSSP21 may include, for example, 1AESS or 5ESS switches manufactured by Lucent Technologies, Inc. (Lucent); DMS-100 or DMS-250 switches manufactured by Nortel Networks Corporation (Nortel); AXE-10 switches manufactured by Telefonaktiebolaget L M Ericsson, or EWSD switches available from Siemens Information and Communication Networks, Inc. Thetandem switch24 is a conventional tandem switch servicing a trunk group associated with thehost MSC31. Thetandem switch24 is capable of recognizing AIN triggers, including triggers associated with calling and called party numbers and trunk groups. Thetandem switch24 may include, for example, 4ESS or 5ESS switches manufactured by Lucent, or DMS-200 switches manufactured by Nortel. The switches may utilize any enabling software compatible with AIN signaling, such as an AIN Release protocol or Carrier AIN (CAIN). However, embodiments of the present invention may include switches and routers used to carry ATM or IP traffic.
• The wireline network portion of the exemplary telecommunications network ofFIG. 2 also includes anSTP22, anSTP25 and a service control point (SCP)23, capable of communicating with one another, and with theSSP21 and thetandem switch24, using out-of-band signaling, such as signaling system 7 (SS7). Although the invention is described in terms of SS7 signaling, it is understood that any comparable signaling transport may be incorporated in the invention, such as X.25 or IP. The out-of-band signaling connections are indicated by dashed lines inFIG. 2. By way of example, theSCP23 is implemented with the Telcordia Integrated Service Control Point (ISCP) Current Generation Platform; the ISCP Next Generation Platform; the Lucent Advantage Service Control Point (LSCP) and Service Package Application (SPA); or the Telcordia Integrated Service Control Point (ISCP), loaded with ISCP software, available from Telcordia, Murray Hill, N.J.
• TheSCP23 includes databases (not pictured) containing information relating to routing calls to the various MSCs in the wireless network, such as thehost MSC31 and the servicingMSC32, discussed below. The databases may be internal or external to theSCP23 and may include a table format. TheSCP23 interfaces with external databases through any compatible protocol, such as SR-3389 or SR-3511. The call flow logic of the present invention may be upgraded to accommodate future AIN releases and protocols and future trigger types, as well as the TGT of the present invention.
• The telecommunications network also includes a wireless network, including thehost MSC31, the servicingMSC32 and anHLR30, associated with at least thehost MSC31. Thehost MSC31 and the servicingMSC32 are essentially exchanges that control the switching between the PSTN and the wireless network to enable communications between wireline telephones (e.g., the calling party telephone20) and mobile stations (e.g., the mobile station35). TheMSCs31 and32 may be, for example, Alcatel 1000 MSC switches manufactured by Compagnie Financiere Alcatel (Alcatel); 5ESS-2000 switches manufactured by Lucent; or DMS-MTX switches manufactured by Nortel. TheHLR30 may be, for example, an Alcatel 1422 HLR/Authentication Center manufactured by Alcatel.
• Connected to theservicing MSC32 is thebase station33, shown communicating via wireless transmissions with themobile station35. In other words, in the exemplary depiction ofFIG. 2, themobile station35 is currently located in a cell associated with thebase station33. Although a single base station is depicted, it is understood that the servicingMSC32, as well as thehost MSC31, is connected to and services multiple base stations or cell sites in the wireless network, and associated controllers. The number of base stations respectively serviced by theMSCs31 and32 is a function of the design of the wireless network. It is further understood that thebase station33 communicates with themobile station35 via any known wireless modulation and transmission techniques, including, for example, advanced mobile phone service (AMPS), code division multiple access (CDMA), direct sequence CDMA (DS-CDMA), cdma2000, IS-95, Global System for Mobile Communications (GSM), time division multiple access (TDMA), or the like.
• As described above, themobile station35 is assigned to thehost MSC31 based on the NPA/NXX of the directory number and/or the wireless carrier of themobile station35. Thehost MSC31 may host a number of mobile stations, depending on various factors, including the number of customers, the identity of the carrier, the capacity of thehost MSC31, and the like. Because thehost MSC31 is associated with themobile station35, it maintains a record of service parameters relating to themobile station35 in theHLR30. The service parameters may include, for example, the type of unit (e.g., cellular telephone, personal digital assistant (PDA), etc.), the make and model of the unit, the carrier, the mobile identification number (MIN), and registration data. When theHLR30 is dedicated to a single carrier, there is no need to include the carrier data in association with themobile station35.
• The registration data stored at theHLR30 indicates the status of themobile station35, including whether themobile station35 is activated and, if so, where themobile station35 is located. The status of themobile station35 is provided automatically whenever it is turned ON through known signaling capabilities of the various types of wireless networks. The activation signaling enables the wireless network to essentially track themobile station35 as it moves throughout the network. When the mobile station is active and located in a cell corresponding to an MSC other than thehost MSC31, such as the servicingMSC32, theHLR30 records the identity of the servicingMSC32.
• TheSCP23 uses the registration data in theHLR30 to route calls efficiently to themobile station35.FIG. 3 is an exemplary call flow diagram showing AIN routing of a call to themobile station35 when themobile station35 is registered at thehost MSC31. In particular, themobile station35 is turned ON in range of a base station (e.g., in a base station cell) connected to thehost MSC31 and accordingly sends activation signals to thehost MSC31 automatically atstep310. Atstep312, thehost MSC31 notifies theHLR30 that themobile station35 is registered at thehost MSC31. TheHLR30 stores the registration data accordingly.
• A calling party subsequently initiates a call at the callingparty telephone20 by dialing the directory number of themobile station35. The call is initially routed to the originatingSSP21 atstep314, which routes the call to thetandem switch24, typically through normal translations, atstep316. TheSSP21 may route the call directly to thetandem switch24, or through any number of intervening end office and/or tandem switches, depending on the layout of the network. Also, theSSP21 may route the call to thetandem switch24 after initially querying theSCP23 for instructions. For example, the calling party directory number, as well as the directory number of themobile station35, may trigger associated AIN services otherwise associated with the call. For instance, the calling party may subscribe to a Home Monitor service, such as the service described in U.S. patent application Ser. No. 09/983,303, filed Oct. 24, 2001, entitled “System and Method for Restricting and Monitoring Telephone Calls” in the names of Nancy A. Book et al., in which outgoing calls are blocked unless the caller successfully enters a bypass personal identification number (PIN). For purposes of subject exemplary call flow, when an AIN service is initially invoked, it is assumed that theSCP23 instructs theSSP21 to complete the call as dialed, resulting in forwarding the call to thetandem switch24 atstep316, as discussed above.
• Thetandem switch24 receives the call and, based on the called party number (i.e., the directory number of the mobile station35), it launches a query in response to a TGT, via the SS7 network and the appropriate STP22 (not pictured inFIG. 3), to theSCP23 atstep318. The TGT query includes various known AIN parameters, used by theSCP23 to process the query and provide appropriate routing instructions.
• In an embodiment of the invention, the TGT query includes the called party number, the calling party number, the trunk group number and route index of the trunk group associated with thehost MSC31, an overflow route index and a billing number. The trunk group number is typically a five-digit number unique to the trunk group of thehost MSC31. The trunk group number is typically arbitrarily assigned by the switch associated with the trunk group, such as thetandem switch24 associated with the trunk group of theMSC31. The trunk group number also populates a table in theSCP23, along with other trunk group numbers in the PSTN, indicating the correlation between the trunk group number and theMSC31. The route index, which is a function of the NPA/NXX, indicates how to point or route traffic to the associated trunk group. The overflow route index indicates an alternative route when trunk groups of the primary route are busy or otherwise unavailable. The billing number provides the identity of the entity to be billed for the call (e.g., the called party, the calling party or a third party provider). The billing number may simply be the calling party number or the called party number, depending on the nature of the call and the billing criteria of the carrier.
• Although the TGT and associated query has been described in terms of particular parameters, it is understood that the communication between thetandem switch24 and theSCP23 may be initiated by any mid-call AIN trigger that provides information sufficient for theSCP23 to identify the host MSC31 (or the trunk group corresponding to the MSC31) as the MSC associated with the directory number of themobile station35, without limiting the scope or the spirit of the present invention.
• TheSCP23 captures the query and identifies the call as a wireless call, based on the called party number and/or the trunk group number. TheSCP23 accordingly launches a query to thehost MSC31 atstep320, based on a previously stored association between the trunk group number (and/or the route index) and thehost MSC31, as discussed above. In an embodiment of the invention, the query launched by theSCP23 is an IS-41 protocol-signaling query, sent through the SS7 network indicated by the dashed lines connecting theSCP23, theSTP22, theSTP25, thehost MSC31 and the servicingMSC32 inFIG. 2.
• When thehost MSC31 receives the query via the STP25 (not pictured inFIG. 3), it contacts theHLR30 atstep322 to retrieve the registration data of themobile station35, based on the called party number. Alternatively, the registration data may be identified and retrieved based on the MIN or other identification number associated with themobile station35. Typically, theHLR30 is associated with a number of MSCs in the wireless network, including the host MSC31, based on the wireless carrier, although there may be crossover among wireless carriers. TheHLR30 looks up the registration data and sends it to thehost MSC31 atstep324. The communication between thehost MSC31 and theHLR30 may include IS-41 protocol signaling through the SS7 network, as indicated by the dashed lines inFIG. 2. Thehost MSC31 then answers the query of theSCP23 by providing the registration data atstep326.
• As stated above, the registration data returned to theSCP23 generally indicates the location of themobile station35. In an embodiment of the invention, the registration data includes either (i) the original called party number (i. e., the directory number of the mobile station35) or (ii) an alternate number identifying a trunk group (e.g., the trunk group number) of an alternate MSC at which themobile station35 is currently registered, such as the servicingMSC32. In an alternative embodiment, any number that distinctly identifies themobile station35, or any number that identifies thehost MSC31 as the MSC servicing the area in which themobile station35 is located (e.g., the trunk group number of the host MSC31), may be substituted for the original called party number without departing from the scope and spirit of the invention. Likewise, in an alternative embodiment, the alternate number may identify the alternate MSC by a number other than the alternate trunk group number, requiring theSCP23 to look up the alternate trunk group number associated with the alternate MSC in an SCP table.
• In the example depicted inFIG. 3, the registration data includes the original called party number. TheSCP23 therefore instructs thetandem switch24 atstep328 to complete the call as dialed. In other words, theSCP23 instructs the tandem switch to route the call to thehost MSC31. Thehost MSC31 receives the call from thetandem switch24 and sends the call toMSC31 and onto thebase station33 that is currently servicing themobile station35. The selected base station pages or otherwise signals themobile station35 and transmits the call, using known wireless modulation and transmission techniques, to themobile station35 to complete the call. As indicated bystep330, which illustrates the talk path, when the user answers the call at themobile station35, the final route of the call includes theSSP21, thetandem switch24 and thehost MSC31.
• In contrast toFIG. 3,FIG. 4 is an exemplary call flow diagram showing AIN routing of a call when themobile station35 is registered at an MSC other than thehost MSC31, such as the servicingMSC32. Themobile station35 is turned ON in range of a base station connected to theservicing MSC32, such as thebase station33, depicted inFIG. 2. Activation signals are sent automatically from themobile station35 to theservicing MSC32 atstep410, by way of thebase station33, as discussed above. Atstep412, the servicingMSC32 notifies theHLR30 that themobile station35 is registered at the servicingMSC32. TheHLR30 stores the registration data accordingly.
• Steps414 through422 ofFIG. 4 are essentially the same assteps314 through322 ofFIG. 3, discussed above. Generally, a calling party initiates a call at the callingparty telephone20 by dialing the directory number of themobile station35. The call is routed to the originatingSSP21 atstep414, which ultimately routes the call to thetandem switch24 atstep416, either through normal translations or based on instructions from theSCP23. Thetandem switch24 receives the call and launches a TGT to theSCP23 atstep418, including at least the calling party number, the called party number, the trunk group number and/or the route index.
• TheSCP23 captures the query and identifies the MSC hosting the directory number of themobile station35 as thehost MSC31. TheSCP23 accordingly launches an IS-41 query to thehost MSC31 atstep420, based on the previously stored association between thehost MSC31 and at least one of the directory number, the trunk group number, and the route index. When thehost MSC31 receives the query, it contacts theHLR30 atstep422 to retrieve the registration data of themobile station35.
• Atstep424, theHLR30 looks up the registration data and sends it to thehost MSC31 atstep424, for example, using IS-41 protocol signaling through the SS7 network. In the example depicted inFIG. 4, the registration data identifies the servicingMSC32, at which themobile station35 is currently registered. Thehost MSC31 answers the query of theSCP23 by providing the registration data atstep426.
• As discussed above, the registration data includes an alternate number identifying the servicingMSC32 and/or the alternate trunk group associated with the servicingMSC32. Upon receipt of the alternate number, theSCP23 instructs thetandem switch24 atstep428 to route the alternate trunk group. When the alternate number identifies only the servicingMSC32, theSCP23 identifies the alternate trunk group associated with the servicingMSC32 through previously stored relationships prior to sending instructions to thetandem switch24. When alternate trunk and/or theservicing MSC32 is located in another LATA or MTA, theSCP23 instructs thetandem switch24 to route the call to an interexchange switch of the other LATA or MTA, such as theIXC41 ofFIG. 6. The process of routing inter-LATA and inter-MTA calls in accordance with the present invention is discussed in detail with respect toFIGS. 5 and 6, below.
• Significantly, upon receipt of routing instructions from theSCP23, the tandem switch24 routes the call to the trunk group associated with the servicingMSC32 without first routing the call through thehost MSC31. Thehost MSC31 therefore is not burdened by receiving the call and subsequently routing it toMSC32 using a back haul facility. Therefore, ports on thehost MSC31, as well as ports onMSC32 are not needlessly occupied by routing the call between the two.
• Of course, routing from thetandem switch24 to the trunk group associated with the servicingMSC32 may be a direct connection or may include routing through any number of intervening switches, depending on the network layout, without departing from the scope and the spirit of the present invention. The servicingMSC32 ultimately receives the call from thetandem switch24, deciphers the directory number and alerts the base station33 (not pictured inFIG. 4), which is determined to be currently servicing themobile station35. Thebase station33 pages or otherwise signals themobile station35, for example, through a control channel associated with thebase station33. When the call is answered,base station33 transmits the call to themobile station35 using known wireless modulation and transmission techniques to complete the call. As indicated bystep430, which is the talk path, the final route of the call includes theSSP21, thetandem switch24 and the servicingMSC32.
• FIG. 5 is a flowchart of exemplary service logic of theSCP23 for routing a telephone call to themobile station35, based on a registration status of themobile station35. At step s510, theSCP23 receives a query over the SS7 signaling network from thetandem switch24 based on a TGT, described above. Based on the trunk group number and/or the route index, theSCP23 identifies thehost MSC31 as the MSC to which themobile station35 is assigned according to its NPA/NXX. At step s512, theSCP23 launches an IS-41 query to thehost MSC31 over the SS7 signaling network, indicated by the dashed line between theSTP22 and theSTP25 inFIG. 2, requesting current registration data of themobile station35. TheSCP23 receives an IS-41 response to the query from thehost MSC31 at step s514, after thehost MSC31 retrieves the registration data from theHLR30, as described above.
• TheSCP23 determines the call routing based on the registration data, as indicated by steps s516, s520 and s524. The order of each determination made by theSCP23, as well as the characterization of the inquiries, represents only one embodiment of the invention and is intended merely to simplify explanation of the invention, and is not intended to limit the scope or the spirit of the invention. At step s516, theSCP23 determines whether the registration data includes the originally dialed number (i.e., the directory number of the mobile station35). In alternative embodiments, theSCP23 determines whether the registration data includes another identification number of themobile station35, such as the MIN, or the trunk group number of thehost MSC31. When the originally dialed number is included, theSCP23 instructs thetandem switch24 at step s518 to complete the call as originally dialed. In other words, thetandem switch24 is instructed to route the call to thehost MSC31.
• When the registration data does not include the originally dialed number, theSCP23 determines whether the registration data includes an alternate number at step s520. When an alternate number is included, theSCP23 translates the alternate number into an alternate trunk group number (unless the alternate number already is a trunk group number, as discussed above) and provides the trunk group number to thetandem switch24, along with instructions to route the call to the alternate trunk group, at step s522. TheSCP23 or thetandem switch24 may determine another tandem switch servicing the alternate trunk group number by translating the alternate trunk group number according to known translation techniques. As explained above, the alternate trunk group number and/or the alternate tandem switch are associated with the MSC at which themobile station35 is currently registered (e.g., the servicing MSC32).
• When theSCP23 determines that registration data does not include an alternate number at step s520 enabling determination of an alternate trunk group number, it must determine the alternate trunk number based on the information provided by the registration data, in combination with available databases. For example, as indicated in step s524, the registration data may include location data relating to the current geographic position of themobile station35.
• At step s524, theSCP23 translates the location data retrieved from thehost MSC31 and theHLR30 into a trunk group number. In an embodiment of the invention, theSCP23 accesses a table indicating geographic service areas corresponding to servicing MSCs and/or trunk group numbers. The location data enables theSCP23 to position themobile station35 within one of the service areas and accordingly identify the appropriate MSC and/or trunk group. When theSCP23 only identifies the servicing MSC, it must additionally perform a look-up of the corresponding trunk group number to complete the translation. At step s522, theSCP23 instructs thetandem switch24 to route the call to an alternate MSC, such as the servicingMSC32, in accordance with the alternate trunk group number identified at step s524.
• Once the trunk group and/or servicing MSC has been identified, the tandem switch24 routes the call accordingly, either directly to the host MSC31 (i.e., thehost MSC31 is also currently servicing the mobile station35) or directly to the tandem switch associated with an alternate MSC, such as the servicing MSC32 (ie., without passing through the host MSC31). It is understood that the call may be routed from thetandem switch24, through any number of intervening switches (other than the host MSC31) to a switch associated with the alternate MSC, without departing from the scope and spirit of the invention.
• An exception occurs when the servicingMSC32 is located in a LATA or MTA different than that of thehost MSC31. For example, assume the location data translated in step s524 indicates a servicing MSC is located in a different LATA, such asLATA2 shown inFIG. 6. In addition to determining the trunk group of the servicingMSC32, theSCP23 also determines the identity of an interexchange switch serving theLATA2, such asIXC41. TheIXC switch41 is identified by theSCP23 in the same general manner in which theSCP23 identifies the alternate MSC, discussed above. Alternatively, assume that theSCP23 receives the identity of theIXC41, along with the alternate number associated with the trunk group of the servicingMSC32, from thehost MSC31/HLR30 at step s520.
• Once theSCP23 has determined the trunk group and/or the interexchange switch information, it provides this information to thetandem switch24, along with instructions to route the call to theIXC41, at step s522. The tandem switch accordingly routes the call directly to theIXC40 in LATA1 (i.e., without passing through the host MSC31), which routes the call toIXC41 inLATA2. TheIXC41, in turn, routes the call to the trunk group associated with the servicingMSC32. In alternate embodiments of the invention, theIXC40 receives the trunk group information from thetandem switch24 or theSCP23. TheIXC40 then sends this information to theIXC41, enabling theIXC41 to identify the trunk group and/or theservicing MSC32 to which the call is to be routed. The same general routing process applies to calls that are inter-MTA, as opposed to inter-LATA.
• Regardless of whether the call is inter-LATA or intra-LATA, theSCP23 continues to monitor the call as it is routed to the appropriate MSC and, at step s526, determines whether the call is answered at themobile station35. When the call is answered, theSCP23 continues to monitor the call until completion, as indicated by step s532. For example, theSCP23 continues to monitor the call at thetandem switch24 and sends thehost MSC31 notification upon a change of status over the out-of-band signaling network. When the call ends, theSCP23 sends a termination notification message to thehost MSC31 via IS-41 signaling at step s534. The termination notification includes, for example, the elapsed time of the call.
• Thetandem switch24 then records the call data records and/or the billing records associated with the call by known recording techniques. For example, thetandem switch24 may record automatic message accounting (AMA) data or other well known call detail records for use by the appropriate carrier. With respect to inter-LATA calls, the AMA data may include a unique AMA sIpID for special processing by the appropriate interexchange carrier.
• In an embodiment of the invention, theSCP23 may determine that there is no answer at step s526. For example, there may be a predetermined number of rings or a busy signal or error indication. When there is no answer, theSCP23 determines whether the response from thehost MSC31 and theHLR30 at step s514 includes a temporary location destination number (TLDN) for voice mail associated with themobile station35. When a voice mail TLDN is not provided, the call simply terminates (e.g., continues to ring or indicate a busy status until terminated by the calling party by hanging up at the calling party telephone20), at which point theSCP23 sends a termination notification message to thehost MSC31 at step s534, indicating the information. When a voice mail TLDN is provided, theSCP23 instructs thetandem switch24 to interrupt the call and reroute to the voice mail TLDN at step s530. The voice mail TLDN likely indicates a directory number terminating within the wireline network, so routing the call to an alternate MSC would not be performed. However, as indicated by steps s532 and s534, theSCP23 continues to monitor the call and sends the termination notification to thehost MSC31 upon completion of the voice mail interaction.
• The present invention enhances the efficiency of routing calls to a wireless directory number through a wireline network by bypassing, at the trunk level, thehost MSC31 whenever themobile station35 is serviced by an alternate MSC. By bypassing thehost MSC31, the call is routed without having to back haul from thehost MSC31 to thetandem switch24 in order to ultimately reach the alternate MSC. Rather, thetandem switch24 is instructed by theSCP23 to route to a tandem switch associated with the alternate MSC, or to an IXC switch when the alternate MSC is in another LATA or MTA, without passing through thehost MSC31. The instruction from theSCP23 is enabled by the AIN TGT trigger, launched by thetandem switch24 to theSCP23 in response to an attempted call termination to thehost MSC31.
• Although the invention has been described with reference to several exemplary embodiments, it is understood that the words that have been used are words of description and illustration, rather than words of limitation. Changes may be made within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the invention in its aspects. Although the invention has been described with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed; rather, the invention extends to all functionally equivalent structures, methods, and uses such as are within the scope of the appended claims.
• In accordance with various embodiments of the present invention, the methods described herein are intended for operation as software programs running on a computer processor. Dedicated hardware implementations including, but not limited to, application specific integrated circuits, programmable logic arrays and other hardware devices can likewise be constructed to implement the methods described herein. Furthermore, alternative software implementations including, but not limited to, distributed processing or component/object distributed processing, parallel processing, or virtual machine processing can also be constructed to implement the methods described herein.
• It should also be noted that the software implementations of the present invention as described herein are optionally stored on a tangible storage medium, such as: a magnetic medium such as a disk or tape; a magneto-optical or optical medium such as a disk; or a solid state medium such as a memory card or other package that houses one or more read-only (non-volatile) memories, random access memories, or other rewritable (volatile) memories. A digital file attachment to email or other self-contained information archive or set of archives is considered a distribution medium equivalent to a tangible storage medium. Accordingly, the invention is considered to include a tangible storage medium or distribution medium, as listed herein and including art-recognized equivalents and successor media, in which the software implementations herein are stored.
• Although the present specification describes components and functions implemented in the embodiments with reference to particular standards and protocols, the invention is not limited to such standards and protocols. Each of the standards for wireless communications and public telephone networks (e.g., AIN, SS7, IS-41, AMPS, CDMA, DS-CDMA, cdma2000, IS-95, TDMA) represent examples of the state of the art. Such standards are periodically superseded by faster or more efficient equivalents having essentially the same functions. Accordingly, replacement standards and protocols having the same functions are considered equivalents.

Claims (20)

1. A method for routing a communication to a wireless device through a wireline network, the method comprising:

storing a registration of a wireless device with a first mobile switching center, in response to the wireless device registering with the first mobile switching center;

receiving a request for the registration of the wireless device with the first mobile switching center; and

providing the registration of the wireless device with the first mobile switching center,

wherein the communication is routed to the wireless device from a node in the wireline network when the node in the wireline network is provided with routing instructions from a controller for the wireline network in response to the controller identifying the registration of the wireless device with the first mobile switching center.

2. The method according toclaim 1,

wherein the controller identifies the registration of the wireless device with the first mobile switching center based on information received from the first mobile switching center, and

wherein the first mobile switching center is registered at the controller as a default host mobile switching center for obtaining the registration of the wireless device.

3. The method according toclaim 2,

wherein the request for the registration of the wireless device is received from the first mobile switching center in response to the first mobile switching center receiving a data query from the controller.

4. The method according toclaim 1,

wherein the controller identifies the registration of the wireless device with the first mobile switching center based on information received from a second mobile switching center which is registered at the controller as a default host mobile switching center for obtaining the registration of the wireless device.

5. The method according toclaim 4,

wherein the request for the registration of the wireless device is received from the second mobile switching center in response to the second mobile switching center receiving a data query from the controller.

6. The method according toclaim 5,

wherein the data query is received by the second mobile switching center from the controller of the wireline network in response to the communication being received at the node in the wireline network and a routing query being received at the controller from the node.

7. The method according toclaim 6,

wherein the registration of the wireless device with the first mobile switching center is provided to the second mobile switching center in response to the request for the registration of the wireless device from the second mobile switching center.

8. The method according toclaim 4,

wherein the communication is routed to the wireless device without passing through the default host mobile switching center.

9. The method according toclaim 1,

wherein the registration of the wireless device with the first mobile switching center is stored in response to receiving the registration of the wireless device with the first mobile switching center from the first mobile switching center.

10. The method according toclaim 1,

wherein the node comprises a first tandem switch associated with a trunk group of the first mobile switching center;

wherein the communication is routed from a second tandem switch to the first tandem switch, and

wherein the controller determines routing data for the communication based on data retrieved from the first mobile switching center in response to a query initiated by the first tandem switch.

11. The method according toclaim 10, in which the communication is suspended at the first tandem switch while the controller forwards a data query to the first mobile switching center.

12. The method according toclaim 1, in which the routing instructions are determined based on a geographic location of the wireless device.

13. The method according toclaim 1, in which the registration with the first mobile switching center comprises location data, indicating a location of the wireless device.

14. The method according toclaim 13, in which the location data comprises an identification of a cell in which the wireless device is located.

15. The method according toclaim 14, in which the wireless device comprises a mobile device configured to operate in a plurality of cells.

16. The method according toclaim 14, in which the wireless device is determined to be registered with the first mobile switching center based on identification of the cell in which the wireless device is located.

17. A home location register for routing a communication to a wireless device through a wireline network, the home location register comprising:

a storage that stores a registration of a wireless device with a first mobile switching center, in response to the wireless device registering with the first mobile switching center;

a receiver that receives a request for the registration of the wireless device with the first mobile switching center; and

a provider that provides the registration of the wireless device with the first mobile switching center,

wherein the communication is routed to the wireless device from a node in the wireline network when the node in the wireline network is provided with routing instructions from a controller for the wireline network in response to the controller identifying the registration of the wireless device with the first mobile switching center.

18. The home location register according toclaim 17,

wherein the request for the registration of the wireless device is received from the first mobile switching center in response to the first mobile switching center receiving a data query from the controller.

19. The home location register according toclaim 17,

wherein the request for the registration of the wireless device is received from a second mobile switching center, which is registered at the controller as a default host mobile switching center for obtaining the registration of the wireless device, in response to the second mobile switching center receiving a data query from the controller.

20. A computer readable medium for storing a computer program for routing a communication to a wireless device through a wireline network, the computer readable medium comprising:

a storing code segment that stores a registration of a wireless device with a first mobile switching center, in response to the wireless device registering with the first mobile switching center;

a receiving code segment that receives a request for the registration of the wireless device with the first mobile switching center; and

a providing code segment that provides the registration of the wireless device with the first mobile switching center,

wherein the communication is routed to the wireless device from a node in the wireline network when the node in the wireline network is provided with routing instructions from a controller for the wireline network in response to the controller identifying the registration of the wireless device with the first mobile switching center.

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