WO2015030643A1

WO2015030643A1 - Method and apparatus for determining the status of a communications terminal

Info

Publication number: WO2015030643A1
Application number: PCT/SE2013/051019
Authority: WO
Inventors: Åke BUSIN; Andreas Hansson
Original assignee: Telefonaktiebolaget L M Ericsson (Publ)
Priority date: 2013-08-30
Filing date: 2013-08-30
Publication date: 2015-03-05

Abstract

The present solution relates to a method and status determination node for determining the status of a communications terminal in particular a location related status of a communications terminal in a mobile communications network, The status determination node comprises a processor and a memory and the memory contains instructions executable by the processor. The status determination node is thereby operative to receive an event notification from a serving node for an event involving the communications terminal and to store in a location database a time stamp of the event notification for the communications terminal. The status determination node is- further operative to determine that a time period counted from the time stamp exceeds a threshold and to send a query to a subscriber database for the status of the communications terminal, and to receive the status from the subscriber database.

Description

METHOD AND APPARATUS FOR DETERMINING THE STATUS OF A COMMUNICATIONS TERMINAL

TECHNICAL FIELD

The present solution relates to a method and apparatus for determining the status of a communications terminal, in particular a location related status of a. communications terminal in a mobile communications network.

BACKGROUND

'fhere exists various occasi ns when there is a need to alert and/or notify individuals. In some situations it is also preferred to be able to notify only individual being present in a specified geographical area. The alert can be a warning for a bush fire, traffic guidance, advertisement etc. but can also be useful for eo- fencing and territorial monitoring.

Mobi le communication systems and the mobile terminals is one example of a system that can be used for such notifications.

The applicants WQ2PQS/Q79Q92 disclose a method and apparatus for mobile subscriber alert notification. A location server recei ves a request for identity of subscribers within an alert area from an alert application and further receives subscriber location data from at least one network node. The location server sends a request to at least one network node to modify the configuration of subscriber location data updating in the network node(s). Subscriber location data is checked and the alert application informed about subscribers located within the alert area.

The applicants patent application WO 98/08350 describes a method and system for selectivel broadcasting a. message to mobile stations traveling within a particular geographic area within a serving mobile switching center (MSC) coverage area. The message is transmitted using for example short message service (SMS) messages to each of the mobile stations determined to be located within the specified geographic area. The determination of to which mobile stations to send the message is done by querying a visiting location register (VLR). WO 00/54524 describes a service by which suppliers of general information can supply general information to the mobile radio network users in a certain geographical area, without the users having to set their mobile stations in the mode for receiving such information.

The service comprises registering a general information message in a general information message register in the mobile radio network including registering an identification of served area. When receiving a location update message from the mobile station the identification of served area is compared with the information of the location of said mobile station included in the location update message, if is determined whether the general information message should be sent t o the mobile station based on the result of the comparison and the general information message is sent to the mobile station if it is determined that the genera! information message should be sent.

^•A problem with the above mentioned known solutions is that only subscribers or terminals presently active within the mobile network can be found. However, at some occasions It is very valuable to detect which of Mobile Network Operator (MNO) subscribers that are roaming ami specifically in which country they are roaming. Such information can then be used to e.g. send SMS to subscribers in a certain country or to collect a list of citizens potentially affected of natural disasters, war outbreak and similar,

In addition to knowing about out-roaming subscribers there is also a need to know if subscribers (own or in-roaming) appears or becomes absent in Public Land Mobile Network (PLMN), This can be used for lawful intercept (e.g. knowing when a person turns off device to avoid being tracked) and personal safety (e.g. knowing thai a person is out of co verage).

In some PLMNs, such as Global System for Mobile Communications (GSM) systems a Home Location Register (HL ) may be queried to list roaming subscribers by making a printout, potentially with some filtering from HLR (e.g. using a "Print Subscriber Roaming Data" command). However, -as the HLR contains a large amount of data such a printout takes significant time. This may result in that warnings (e.g. for a tsunami) don^'t get sent in time.

It is consequently a problem to efficiently determine the status of a terminal such as whether it is roaming in anothe network or detached, in order to for example enable the prompt sending of warning messages. SUMMARY

It is an object of the invention to provide a meihod and apparatus for determining a status of a comrn unieat i oris term ina 1. A first aspect of the invention relates to a method performed by a status determiner for determining a status of a communications terminal. The status determiner receives an event notification from a serving node for an event involving the communications terminal. A time stamp of the event notification for the communications terminal is stored in a location database. It is determined that a time period counted from the time stamp exceeds a threshold and a query is sent to a subscriber database for the status of the communications terminal and the status of the communications terminal is received irom the subscriber database.

A second aspect of the invention relates to a status determination node for determining a status of a communications terminal. The status determination node comprises a processor and a memory and the memory contains instructions executable by the processor. The status determination node is thereby operati e to receive an event notification from a serving node for an event involving the communications terminal and to store in a location database a time stamp of the event notification for the communications terminal. The status determination node is further operative to determine that a time period counted from the time stamp exceeds a threshold and to send a query to a subscriber, database for the status of the communications terminal, and to receive the status from the subscriber database.

A third aspec t of the invention relates to a computer program comprising computer readable code means, which when run in a computer being configured as a status

determination node for determinin a status of a communications terminal, the computer readable code means causes the computer to receive an event notification from a serving node for an event involving the -communications terminal and to store in a location database time stamp of the event notification for the communications terminaL The computer readable code means further causes the computer to determine that a time period counted from the time stamp exceeds a threshold and to send a query to a subscriber database for the status of the communications terminal, and to receive the status from the subscriber database. A fourth aspect of the invention relates to a computer program product comprising a. computer readable medium and a computer program stored on the computer readable medium. The computer program comprises computer readable code means, which when run in a computer being configured as a status determination node, the computer readable code means causes the computer to receive an event .notification from a serving node for an event involving the communications terminal and to store in a location database a time stamp of the event notification for the communications terminal. The computer readable code means further causes the computer to determine that a time period counted from the time stamp exceeds a threshold and to send a query to a subscriber database for the status of the communications terminal and to receive the status from the subscriber database,

A fifth aspect of the invention relates to a location server including a status

determination node for determining a status of a communications terminal. The status determination node comprises a processor and a memory and the memory contains instructions executable by the processor. The status ^'.determination, node is. thereby operative to receive an event notification from a serving node for an event involving the

communications terminal and to store in a location database a time stamp of the event notification for the communications terminal . The status determination node is further operative to determine -that a time period counted from the time stamp exceeds a threshold and t o seed a query to a subscriber database for the status of the communications terminal, and to receive the status from the subscriber database.

A. sixth aspect of the invention relates to a status determination node for determining a status of a communications terminal. The status determination node comprises an interface module for receiving _.an event, notification from a serving node for an event involving the communications terminal and a storage module for storing in a location database a time stamp of the event notification for the communications terminal. The status determination nod also comprises a determination unit for determining that a time period counted from the time stamp exceeds a threshold. Further comprised is a query module for sending query to a subscriber database for the .status of the communications terminal and a receiver unit for receiving the status of the communications terminal from the subscriber database. it is thus an advantage that the present invention enables faster status determination of subscribers, for example determining roaming status of subscribers registered as roaming in a subscriber database such as an HLR/! ISS. Embodiments of the invention will now be described in more detail with reference to the enclosed drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a block, diagram showing an architecture overview of a spatial trigger system according to the prior art.

Figure 2A is a block diagram showing an architecture overview^" of a system including a Status Determiner for determining a status of a communications terminal according to an example embodiment.

Figure 2B is a block diagram showing the content of an example location database 130.

Figure 3 is a flow chart showing the steps performed by a Status Determiner. for determining a status of a communications terminal according to an example embodiment. Figure 4 is a message sequence diagram showing an exemplar signaling diagram for method for determining a status of a communication terminal.

Figure 5 is a block diagram showing an exemplary embodiment of a Status Determiner in the form of computing system environment.

Figure 6 is a block diagram showing an exemplar)' embodiment of a computer program and a computer program product.

DETAILED DESCRIPTION

The following detailed description of the exemplary embodiments refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements.

Figure 1 is a block diagram showing an architecture overview of a spatial trigger system according to the prior art. The services that spatial triggers enable are services that are dependent on how a subscriber moves. A couple of examples are:

* Inform a service when a subscriber enters an .area inform a service when a subscriber leaves an area · inform a service when two subscribers are getting close to each other.

Location based/trigger applications 110 request a Location Determiner 120 of a Location. Server (Location Server terminology according to QMA and Gateway Mobile Location

Centre GMLC is. the term used by 3GFP) to get informed when a specific subscriber enters/leaves a geographical area or getting close to another specific subscriber. The DMA standardize Mobile Location Protocol MLP may be used as a plication' interface 130 between the trigger applications 1 10 and the Location Server 125.

The Location Determiner is responsible for . updating a Location Database DB 135, which can be stand alone or co-located with the LS. with subscriber locations received front other nodes in the mobile network. The Location Server is also responsible for checking the different criterion and inforra the trigger application when a criteria is fulfilled. The quality of the locations in the DB 135 is dependent of the update frequency of the subscriber locations.

A Core Network CN 1 0 including serving nodes Mobile Switching Center MSG, Serving GPRS Support Node SGSN and/or Mobility Management Entities M B sends passive data to the Location Server when a Mobile Statio MS 160_f sometimes referred to as a User

Equipment UE is in contact with a Home Public Land Mobile Network 100 via cells 160 managed by the Radio Access Network RAN 170. Passive data is referred to as data which is unsolicited, i.e. not explicitly requested, by the receiver, or event data indicating a data content and reason for its transmission. Examples of this are network events such as when subscriber sending SMS, making a call, location area update and periodic location update. The passive data include MS identity and location related information such as cell identity.

Figure 2A is a block diagram showing an architecture overview of a status

determination system 200 according to an example embodiment. A location based application such as an alert application 205 requests the Location Server 125 for status of subscribers by using MLP.

The status may relate to a location status for subscribers that are roaming, or for the location status of specific subscribers. Notification/alert may then be sent to the subscribers by the application, Since the alert application and location server/location database may use different representation of the geographical area it is not required that the area requested from the alert application and the area identified by the location server/location database is strictly identical. The application notifies the subscriber according to the customers need via SMS 212, MMS 214, voice 216 or by other methods.

A Statu Determiner 210 of the Location Server 125 is responsible for an initial searching in the Location Database LDB 130 for all requested subscribers. It is also responsible for updating the LDB with subscriber locations received from other nodes in the mobile network.

The CN 140 sends passive dat to the Location Server when the MS i in contact with the mobile net. Examples of this are network events such as subscriber sending SMS, making call location area update and periodic location update. The passive data include MS id and location related information.

The system comprises a HPL N 100 and a Visited Public Land Mobile Network V.PLMN 215, Ifa Spatial Trigger (ST) function 220 is activated in serving nodes (MSC/SGSN/MME) of the core network 140 of the HPLMN the Location Server 125 will get event notification any time a MS performs certai activities such as attach, detach, location update, voice call setup and sendee requests in the HPLMN.

An advantage with the present solution is that when the invention is executed in a system where spatial triggering enabled positioning is already activated the additional load to positioning system for performing the herein described status detennination is very low.

The Status Determiner 21.0 in the Location Server 125 can get teal time event notifications from an MSC/SG SN/MME in the Core Network 140 of the Home PLMN (HPLMN) when any communications terminal MS 230 within the HPLMN performs certain actions as location update procedure, initiate calls, sends SMS and initiate/release data, connections. Event data related to the latest of these events are stored in the LDB 135 and the Status Determiner will thus be aware of a!l subscribers that at least once have been attached to the PLMN since the Location Server was acti vated. Such event data includes type of event, e.g. attach, detach, location update, voice call setup and service requests.

The event data stored by the Status Determiner ma also include a timestamp which may be received with the event notification or may be determined by the Location Centre at the time of receipt The time stamp may represent the time the event occurred at the network element or terminal, or the time at which it was received by the Status Determiner. The Status

Determiner will thus have a time stamp for the last activity of each MS i the HPLMK.

A Roaming Detection RD function of the Status Determiner will check if the time since last event notification exceeds a configured or dynamic timeout time for each known MS. In such ease the Status Determiner will make queries to a Subscriber Database 240, such as an H me Location Register HLR/Home Subscriber Server HSS, to determine if the MS is attached t a V LMN 215. The queries can be applicable standard or proprietary message for routing e.g. the Mobile Application Part (MAP) message Send Routing for LC$₉ Send Routing for SMS or Any Time interrogation messages defined by 3 GPP.

It is thus an advantage that the solution may use standardized signaling toward an HLR or HSS.

Consequently, if the time since last activity of an MS in HPLMN exceeds a timeout the subscriber will be considered a potential roamer. For these subscribers the Status Determiner will query the Subscriber Database to find a serving network, or to find if the MS is detached.

Additionally the query of Subscriber Database can be made periodically and if needed have a dynamic setting of the periodicity to reduce the load on Subscriber Database.

In addition to discovery of roaming terminals the present solution can be used to detect other statuses of an MS based on information in the event notification from the serving nodes and the response from the Subscriber Database. Example of such status is MS being unreachable or detached.

The MS status can then be delivered to Location Based Applications such as Alert

Application 210, either on request or as a. stream continuously reporting changes in status of mobile stations. The Status Determiner is here descri bed as a functional unit of the Location Server 125 but can also be provided as a stand-alone unit

Figure 2B shows the content of an example location database 30. Figure 3 is a flow chart showing the steps performed by a Status Determiner for determining a status of a comniunications terminal according to an example embodiment .

The method starts in step 305 with the Status Determiner receiving an event notification from a serving node (14 . 150) such as a MSC, SGSN or MME for an event involving the terminal. Examples of such event notifications may be any one of a location update indication, location update procedure, call initiation, SMS transmission, data connection initiation or data connection release.

The Status Determiner stores a time stamp of the event notification for the terminal in a database such as the locatio database 130 in step 310. The storing may involve only storing in: the location databai>e the latest of plural received event notifications tor the terminal. For the terminal shown in figure 2B having MS!SDN +46703123123 as identity a Location

Update Event was .received on 20130826 at 14:27

In step 315 it is detennined that a time period counted from the time stamp exceeds a threshold. The threshold may be a configured timeout time or a dynamically determined timeout time. In the exam le of figure 2B, for the terminal with MSISDN +46703123123 as identity a Location Update Event was received on 201 0826 at 14:27. In this example the present time is exemplifietl to be 201 0826 at 20:00 and the threshold time to be 6 hours. Thus, the location update received at 14:27 is less than 6 hours old and thereby still within the threshold time. The terminal is thus regarded as active in the HPLMN. The same applies for the terminal having MSISDN +46703456456 where an Attach event was received a 15:35. On the contrary, the terminal with MSISDN +46703890890 was involved in its latest event, a Location Update, on 20130824 at 10:45. In this example this is deemed to be older than the threshold value of 6 hours and the status is therefore considered unknown. Advantageously, the threshold is set to such a time period that roaming users thai recently was attached to a PLM^'N in a country but later would be purged, i.e. subscriber is marked as absent in subscriber database for example due to the mobile terminal being switched off for an extended duration, would yet be detected and possible to query for the Status Determiner. A query is sent to a subscriber database in step 320 requesting the status of the terminal with SIS^'DN +46703890890.The query may be any one of a Send Routing for LCS, Send Routing for SMS or Any Time Interrogation messages, The query may be sent to the subscriber database periodically, for example using a dynamically determined setting of the periodicity. Using such dynamically determined periodic setting effects in reduced load on the subscriber database. For example, the periodicit may be based on HL HSS load or traffic load in other involved nodes,

A response including the status, which may relate to an explicit or implicit location .status of the terminal, is received from the subscriber database in step 325. The received status of the terminal ma indicate that the terminal is roaming within a visited public land mobile network. In such case the response may include a mobile network code (MNQ used in combination with a mobile country code (MCC) (also known as a "MCC MNC tuple") to uniquely identify a mobile phone operator/earner wiierein the terminal is currently roaming. The received status of the terminal may also indicate that the terminal is unconnectable e.g. that a subscriber of the present HPLMN (for example MSISDN +467034324323) or an. i«- roaming (for example MSIS^'DN +1 11098654) subscriber has become absent, being unreachable or Detached, In the present example, the response for MSISDN +467038908-90 includes the information ROAM 310:030 indicating that the subscriber is roaming within the United States of America (M.C0310) and is attached to a network of AT&T Mobile

(MMO030). in step 330 the status response of ROA 31.0:030 for MSISDN +46703890890 is stored i the location database 130, in a step 335 the Status Determiner receives a request for the status of terminals from for example a location based application such as an alert application. The request may relate to for exam pie roaming terminals, detached terminal or any other status being determined and may relate to specified terminals or to all terminals/groups of terminals being tracked.

Following the request for status, the Status Determiner retrieves the status of the requested terminals from the Location Database in step 340. For example, a request for subscribers presently roaming in the United States of America would return MSISDN +46703890890, In a similar manner, the identity of the subscriber or terminal ma be utilizing the International mobile Subscriber identity (I S!) or International Mobile Equipment Identity (IME!)

In step 345 a status response is sent to the receiving node such as the alert application or any type of location based applieai ion. Responses can be sent once per request or they may be sent as a stream of continuous reporting messages. For example, once the receiving node has placed a subscription^' for a status of terminal^'s the Status Determiner may be arr nged for continuing sending status update as a stream of messages when for example an event involving a requested terminal is received by the status Determiner or at a dynamic or configured frequency.

Figure.4 is a message sequence diagram showing an exemplary signaling diagram fo a method for determining a status of a communiciitions terminal.

In step 410 a Statu Determiner of a Location Server 125 receives an event notification from a serving node 1.40 in the HPLMN (e.g. an MSC, SGSN orMME). for a mobile terminal MS A. Event notifications are sent e.g. when a connection is established to the MS in order to establish a voice call, sending/receiving packet data and similar purposes.

In step 420, if the MS is not stored in the location database in the Location Server it will be added. Then the MS will be given state "Not roaming" or "Active" as the event took place in serving node in HPLMN. A "Notification timer^' is then started or restarted if already running to count the time from the event to enable comparison against a threshold value, A time stamp of the event notification for the terminal is therefore stored.

The "Notification timer" is set such that a new event with high likelihood should have occurred if the MS is still available in the HPLMN. In step 430, once the "Notification timer^5' elapses, i.e. it is determined that a time period counted from the time stamp exceeds a threshold and the Status Determiner will try to find out if MS is still "not roaming".

In ste 440 a query to a subscriber database such as an I !LR/HSS will be made to find out the serving node for MS A. The subscriber database will provide current serving node or provide error code indicating that serving node is not known in step 450.

Depending on the response from subscriber dalabase the Status Determiner will update the status of the M i n the locati on database in step 460. If e.g. the subscriber database indicates a serving node outside HPL N then the status will be changed to "Roaming". Status may also indicate that the location of the MS is not known which may be consi dered as an implicit location status.

In step 470, at any time an Application 1 10, for example a Location Based Service, may query the Status Determiner for status of speci fic MS or for listing e.g. of all Ss that are roaming.

The Status Determiner will query the location database in step 480 and create list of e.g. ail MSs marked '"Roaming" and m ste 490. A report with the listing will be repotted to the Application 1 10.

Figure 5 below is a block diagram■showing an exemplary' embodiment of a Status Determiner according to the disclosed solution in the form of computing system environment 500.

Although as made clear above, the computing system environment 500 is only one example of a suitable computing environment for a status Determiner and is not intended to suggest any limitation as to the scope of use or functionality of the claimed subject matter. Further, the computing environment 500 is not intended to suggest any dependency or requirement relating to the claimed subject matter and any one or combination of components illustrated in the example operating environment 500.

An example of a device for implementing the previousl described innovation includes a general purpose computing device in the form of a computer 510. Components of computer 51 can include* but are not limited to, a processing unit 520, a system memory 530, and a system bus 521 that couples various system components including the system memory to the processing unit 520. The system bus 521 can be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures.

Computer 510 can include a variety of transitory and non-transitory computer readable media. Compute readable media can be an available media that can be accessed by computer 510, By way of example, and not limitation, computer readable media can comprise computer storage media and communication media. Computer storage media includes volatile and nonvolatile as well as removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CDRO , digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic ^'tape, magnetic disk storage o other magnetic storage devices, or any other mediu which can be used to store the desired information and which can be accessed by computer 510. Communication media can embody computer readable instructions, data structures, program modules or other data in a modulated dat signal such as a carrier wave or other transport mechanism and can include any suitable information delivery media. The system memory 530 can include computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM) and/or random access memory (RAM). A basic input/output system (BIOS), containin the basic routines that help to transfer information between elements within computer 510, such as during start-up, can be stored in memory 530. Memory 530 can also contain data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit 520. By way of non-limiting example, memory 530 can also include an operating system, application programs, other program modules, and program data.

The system memory 530 may include an Execution Unit 580 as a software module loaded in the memory and processab!e by the processing unit, or other circuitry, adapting the computer for performing the steps of the Status Determiner according to the disclosed solution. For example, the execution unit may be adapting the computer 510 into a status determination node for determining a status of a terminal. The status determination node comprises a processor and a memory and the memory contains instructions executable by the processor. The status determination node is thereby operative to receive an event notification from a serving node for an event involving the terminal and to store in a location database a time stamp of the event notification for the terminal. The status determination node is further operative to determine that a time period counted from the time stamp exceeds a threshold and to send a query to a subsci iber database for the status of the terminal, and to receive the status from the subscriber database. Modules in embodiments may be implemented as a computer program running on the processor, in one such example, the status determination node comprises an interface module for receiving an event notification from a serving node for an event involving the

communications terminal and a storage module for storing in a location database a time stamp of the event notification for the communications terminal. The status determination node also comprises a determination, unit for determining that a time period counted from the time stamp exceeds a threshold. Further comprised is a query module for sending a query to a subscriber database for the status of the communications terminal and a receiver unit for receiving the status of the communication terminal from the subscriber database.

The computer 510 ca also include other removable/non-removable and volatile/nonvoiatile computer storage media. For example, computer 510 can include a hard disk drive thai reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive that reads from or wri es to a removable, nonvolatile magnetic disk, and/or an optical disk drive- that reads from or writes to a removable, nonvolatile optical disk, such^' .as. a CD-ROM or other optical media. Other removabie/non-removable, volatile/nonvolatile- computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM and the like. A hard disk drive can be connected to the system bus 521 through a non-removable memory interface such as an. interface, and a magnetic disk drive or optical disk drive can be connected to the system bus 521 by a removable memory interface, such as an interface. A user can enter commands and information into the computer 510 through input devices such as a keyboard or a pointing device such as a mouse, trackball, touch pad, and/or other pointing device. Other input devices can include a microphone, joystick, game pad. satellite dish, scanner, or similar devices. These and/or other input devices can be connected to the processing unit 520 through user input 540 and associated mterface(s) that are coupled to the system bus 521 , but can be connected by other interface and bus structures, such as a parallel port, game port or a universal serial bus (USB),

A graphics subsystem can also be connected to the system bus 521. in addition, a monitor or other type of display device can be connected to the system bus 521 through an interface, such as output interface 550, which can in turn communicate with video memory, in addition to a monitor, computers can also include other peripheral output devices, such as speakers and/or printing devices, which can also be connected, .through output interface 550.

The computer 510 can operate in a networked or distributed environment using logical connections to one or more other remote computers, such as remote server 570, which can in turn have medi capabilities different from device 510. The remote server 570 can be a personal computer, a. server, a router, a network PC, a peer device or other common network node, and/or any other remote media consumption or transmission device, and can include any or all of the elements described above relative to the computer 510. The logical

connections depicted in FIG. 5 include a network 571 , such as a local area network (LAN) or a wide area network (WAN), but can also include other networks/buses.

When used in a LAN networking environment, the computer 510 is connected to the LAN. 571 through a network interface or adapter. When used in a WAN networking environment, the -computer 510 can include a communications component, such as a modem, or other means for establishing communications over a WAN, such as the Internet. A communications component, such as a modem, which can be internal or external, can be connected to the system bus 521 through the user input interlace at input 540 and/or other appropriate mechanism.

In a networked environment, program modules depicted relative to the computer 510, or portions thereof can be stored in a remote memory storage device. It should be noted that the network connections shown and described are exemplary and other means of establishing a communications link between the computers can be used. Figure 6 is a block diagram showin an exemplary embodiment of a computer, program 620 and a computer program product 610. The computer program product may comprise any type of computer readable media able to convey the computer program.

Additionally, it should be noted that as used in this application, terms such as ''component," "display,^'" 'Interface ^* and other similar terms are intended to refer to a. computing device, ei ther hardware, a combination of hardware and software, software, or software in execution as applied to a computing device. For example, a component may be, bu is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program and a computing device. As an example, both an application running on a computing device and the computing device can be components. One or more components can reside within a process and/or thread of execution and a component can be localized on one computing device and/or distributed between two or more computing devices, and/or communicatively connected modules. Further, it should be noted that as used In this

application, terms such as "system user," "user," and similar terms are intended to refer to the person operating the computing device, referenced, above.

When an element is referred to as being "connected", "coupled", "responsive", or variants thereof to another element, it can be directly connected, coupled, or responsive to the other .element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected", "directly coupled", "directly responsive", or variants thereof to another element, there are no intervening elements present. Like numbers refer to like elements throughout. Furthermore, "coupled", "connected", "responsive", or variants thereof as used herein may include wire!essly coupled, connected, or responsive. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Weil-known functions or constructions may not be- descri ed in detail for brevity and/or clarity. The term "and/or" includes any and all combinations of one or more of the associated listed items. As used herein, the terms "comprise", "comprising", "comprises", "include",

''including", "includes", "have", "has", "having", or variants thereof are open-ended, and include one or more stated features, integers, elements, steps, components or functions hut does not preclude the presence or addition of one or more other features, integers, elements, steps, components, functions or groups thereof Furthermore, as used herein, the common abbreviation "e.g.", which derives from the Latin phrase "exempli gratia," may be used to introduce or specify a general example or examples of a previously mentioned item, and is not intended to be limiting of such item. The common abbreviation "i.e.", which derives from the Latin phrase "id est," may be used to specify a particular item from a more general recitation.

It should also be noted that in some alternate implementations- the functions/acts noted in the blocks may occur out of the order noted in the flowcharts, for example, two blocks shown in succession may in fact be executed substantiall concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Moreover, the functionality of a given block of the .flowcharts and/or block diagrams may be separated into multiple blocks and/or the functionality of two or more blocks of the fl wcharts and/or block diagrams may be at least partially integrated.

Finally, other blocks may be added/inserted between the blacks that are illustrated. Moreover, although some of the diagrams Include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows.

Many different embodiments have been disclosed herein, in connection with the above description and the drawings, ft will be understood that it would be unduly repetitious and obfuscating to literally describe and ii usirate every combination and subcombination of these embodiments. Accordingly, the present specification, including the drawings, shall be construed to constitute a complete written description of various exemplary combinations and subcombinations of em bodiments and of the manner and process of making and using them, and shall support claims to any such combination or subcombination.

Many variations and modifications can be made to the embodiments without substantially departing from the principles of the present solution. All such variations and modifications are intended to be included herein within the scope of the present solution.

Claims

1. A method performed by a status determiner (210) for determining a stat us of a communicaiions terminal (230) comprising the status determiner performing the steps of: - receiving (305) an event notification from a sewing node (140, 150} for an event involving the communications terminal;

storing (310) in a location database (130) a time stamp of the event notification for the communications terminal:

determining (31.5) that a time period counted from the time stamp exceeds a threshold; - sending a query (320) to a subscriber database (2 0) for the status of the

communications terminal ;

receiving (325) the status of the communicaiions terminal .from the subscriber database.

2. A method according to claim 1 wherei the received status of the communications terminal indicates that the communications terminal is roaming within a visited public land mobile network.

3. A method according claims 1 wherein the received status of the communications terminal indicates that the communications terminal is uncorrectable..

4. A method according to any one of the preceding claims wherein the ste of storing a time stamp comprises storing i the location database t e latest of plural received event notifications for the communications terminal.

5. A method according to any one of the preceding claims wherein the threshold is a configured timeout time or a dynamically determined timeout time.

6. A method according to any one of the preceding claims wherein the quer sent to the subscriber database is any one of a Send Routing for LCS, Send Routing for SMS or Any

Time Interrogation messages.

7, A method according to any one of the preceding claims wherein the query sent to the subscriber database is sent periodically.

8, A method according to claim 7 wherein the query sent to the subscriber database is sent, using a dynamically determined setting of the periodicity.

9. A method according to any one of the preceding claims comprising, after the step of recei ving the status of the communications terminal irom the subscriber database the further step of sending (345) a status response to a receiving node (205) as a stream of continuous reporting messages.

10. A method according to any one of the preceding claims wherein the event notification is any one of a locatio update indication, location update procedure, call initiation, SMS transmission, data connection, initiation or data connection release,

11. A status determination node (210) for determining a status of a communications terminal (230) comprising a processor (620) and a memory (630), said memory containing instructions executable by said processor whereby said status determination node is operative to: receive (305) an event notification fro a serving - node (140, 350) fo an event involving the communications terminal;

store (330) in. a location database (1.30) a time stamp of the event notification for the ^■communications terminal;

- .determine (315) that a time period counted from the time stamp exceeds a threshold; send a query (320) to a subscriber database (240) for the status of the communications terminal;

receive (325) the status of the communications terminal from the subscriber database.

12. A status determination node according to claim 11 wherein the received status of the communications terminal indicates that the communications terminal is roaming within a visited public land mobile network.

13. A status determination node according to claims 1 1 wherein the received status of the ^■communications terminal indicates that the communications terminal is uneonnectable,

14. A status determination node according to any one of clai ms 1 1 -13 wherein the status determination node is further operative to store in the location database the latest of plural received event notifications for the communications terminal.

15. A status determination node according to any one of claims 1 1 -14 wherein the threshold is a configured timeout time or a dynamically determined timeout time.

16. A status determination node according io any one of claims 1 1-15 wherein the query sent to the subscriber database is any one of a Send Routing for LCS, Send Routing for SMS or Any Time interrogation messages.

1 7. A status determination node according to any one of claims 1 1 -16 wherein the query sent to the subscriber database is sent periodically,

18. A status determination node according to. claim 17 wherein .the quer is.^' sent using a dynamically determined setting of the periodicity.

19. A status determination node according to any one of claims I I «18 the status determination node is farther operative to send (345) a status response to a receiving node (205) as a stream of continuous reporting messages.

20. A status determination node according to any one of claims 1 1-1 wherein the event notification is any one of a location update indication, location update procedure, call initiation, SMS transmission, data connection initiation or data connection release.

21 A Location Server (125) including a status determination node according to any one of claims 1-20.

22. A computer program (620) comprising computer readable code means, Which whea run in a computer (510) being configured as a status determination node (210) for determining a status of a communications terminal (230), the computer readable code means causes the computer to perform the following steps:

- receiving (305) an event notification from a serving node (140, 150) for an event involving the communications terminal;

storing (310) in a location database (130) a time stamp of the event notification for the communications terminal;

determining (315) that a time period counted from the time stamp exceeds a threshold; - sending a query (320) to a subscriber database (240) for the status of the

communications terminal;

receiving (325) the status of the communications terminal from, the subscriber database.

23. A computer program product (610), comprising a computer readable medium and a computer program (620) according to claim 22 stored on the computer readable medium.

24. A status determination node (210) for determining a status of a communications terminal (230) whereby said status determination node is comprising:

an interface module for receiving (305) an event notification from a serving node (140, 150) for an event involving the communications terminal;

- a storage module for storing (310) in a location database (130) a time stamp of the event notification for the communications terminal;

a determination unit for determining (315) that a time period counted from the time stamp exceeds a threshold]

a query module for sending a query (320) to a subscriber database (240) for the status of the communications terminal;

a receiver unit for receiving (325) the status of the communications terminal from the subscriber database.

25. A status determination node according to claim 24 further comprising a kansmitter module for sending (345) a status response to a receiving node (205) as a stream of continuous reporting messages.