Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
  • H04L65/10—Architectures or entities
  • H04L65/1016—IP multimedia subsystem [IMS]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
  • H04W4/02—Services making use of location information
  • H04W4/029—Location-based management or tracking services
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
  • H04L65/10—Architectures or entities
  • H04L65/1063—Application servers providing network services
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L67/00—Network arrangements or protocols for supporting network services or applications
  • H04L67/50—Network services
  • H04L67/54—Presence management, e.g. monitoring or registration for receipt of user log-on information, or the connection status of the users
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L67/00—Network arrangements or protocols for supporting network services or applications
  • H04L67/50—Network services
  • H04L67/52—Network services specially adapted for the location of the user terminal
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
  • H04W4/02—Services making use of location information

Definitions

• This invention relates to a switching center of a cellular network providing presence information and to a method for providing presence information of a user in a cellular network to a presence service entity.
• 3GPP TS 23.292 specifies the architectural requirements for delivery of consistent IMS (IP Multimedia Subsystem) services to the user regardless of the attached access type (e.g. circuit switched (CS) domain access, or IP-CAN).
• IMS IP Multimedia Subsystem
• the solution is applicable for user entities (UE's) with or without ICS functionality, and is applicable for the following deployment scenarios:
• ICS enables IMS services when using circuit switched access for media transport.
• a user entity 100 accesses a Mobile Switching Center (MSC) Server no via a 2G/3G access 120.
• An IM Mediagateway (IM-MGW) 130 is connected to the MSC Server 110.
• An ICS application server 140 is used providing functions specific to IMS centralized services.
• a CSCF (Call Session Control Function) unit 160 is a component of the IP Multimedia Subsystem controling the connection of the user entity 100 and establishes multimedia sessions for the user entity 100.
• 3GPPTS 23.141 specifies the presence service which provides the ability for the home network to manage presence information of a user's device, service or service media even whilst roaming.
• a user's presence information may be obtained through input from the user, information supplied by the network or information supplied by elements external to the home network. Consumers of presence information, i.e. watchers, may be internal or external to the home network.
• a presence service entity 200 comprises a presence server 210 contained in a home network of a mobile user entity subscribing to a cellular network which can receive presence information from different resources.
• Information about the presence of a mobile user entity may be received from a presence network agent 290 receiving information from various network nodes, such as the Mobile Switching Center server (MSC server).
• MSC server Mobile Switching Center server
• the Pc Interface is using a CAMEL (Costumized Application for Mobile Network Enhanced Logic) mechanism for information retrieval.
• a Pen Interface can be used to forward the information to the presence server 210.
• a presence information may be provided by the user through a presence user agent 280, the presence user agent being the element that collects and sends user related presence information to the presence server 210.
• the capability of the Ut Interface may be reused.
• the Peu Interface may be used to forward the information to the presence server 210.
• presence information is provided to the presence server from outside the network through the presence external agent 270 using the Pex Interface.
• a Presentity presence proxy 220 presentity being a combination of the expressions "presence” and "entity”, is a functional entity providing the presentity-related functionality such as determining the presence server associated with a presentity.
• a watcher presence proxy 240 describes the entity that provides watcher related functions such as authentication of watchers, a presence list server 260 being the functional entity storing grouped lists of watched presentities and enabling a watcher application to subscribe to the presence of multiple presentities using a single transaction. Furthermore watcher applications 250 are provided.
• Presentity usually refers to a person and describes availability and willingness of this person to communicate via a set of communication services.
• Pep and Pen refer to the RFC 3863 for support of transport of presence information under the PIDF (Presence Information Data Format).
• Pep provides mechanisms for the presence user agent to obtain information on watcher subscriptions to the presentity's presence information.
• P-CSCF proxy CSCF
• S-CSCF server CSCF
• the reference point presence network agent-MSC server /VLR Pc allows the MSC server/VLR to report the mobility management related events to the network agent, such as attach, detach, location area update, and may allow the MSC server/VLR to report call-related events such as call set-up with the bearer information and call release.
• This reference point may allow the MSC server/VLR to report mobility states such as detached, idle and connected and call states such as busy with bearer information and idle.
• the network provided information is not affected by the support of ICS. So the CAMEL implementation in the ICS-enhanced MSC server can still be used for providing presence information.
• the Pep and Peu Interface are usually direct packet interfaces from the user agent in the terminal to the presence infrastructure. Assuming that even non-ICS terminals support direct packet communication, this interface is in theory fully available for ICS subscribers using non-ICS-enabled terminals.
• the reliability of the packet switched interface furthermore depends on the radio capabilities of the terminal. For GSM radio access this requires either class A terminals or DTM support in the RAN and the enter terminal. There are no class A terminals available and only very few DTM terminals.
• the 3GPP TS 23.141 reuses the CAMEL capability to provide network-based presence information. This means that presence information can only contain information available in CAMEL which also depends on the support level of CAMEL. Since the CAMEL- standardisation has come to an end it is very unlikely to get new information into CAMEL to improve the presence information in level of detail.
• a switching center of a cellular network comprising a presence information detecting unit detecting a presence information of a user.
• the switching center furthermore comprises an interface to the presence service entity providing the presence information of the user to said presence service entity.
• an ICS-enhanced switching center is used providing presence information.
• the switching center can provide the presence information the user entity is not able to provide in case of a non-ICS-enabled user entity.
• the presence information detecting unit detects user-related information, the interface comprising a first interface providing the user related presence information to the presence service entity.
• the ICS-enhanced server is used to complement the user agent provided presence information during an ongoing call for ICS subscribers roaming in GSM radio accesses.
• the switching center comprises a call status determination unit adapted to determine a call status of that user wherein the presence information detecting unit detects the presence information of said user when the call status determination unit has determined an established call for that user.
• the switching center takes over the role of the presence user agent providing the presence information to the presence server.
• the switching center may be a mobile switching center controlling the calls for mobile user entities. However the switching center may be any call control node controlling calls of a mobile user entity.
• a transmission status determination unit may be provided determining whether, for that user packet switched and circuit switched data transmission is possible in parallel.
• the presence information detecting unit detects the presence information and the first interface provides the presence information to the presence service entity. More specifically when the transmission status determination unit determines that no parallel transmission of packet switched and circuit switched data is possible the presence information detecting unit takes over the role of the presence user agent, and the first interface provides the presence information to a presence proxy of the presence service entity.
• the call status determination unit and the transmission status determination unit help to determine when the switching center should take over the role of the presence user agent. When an established call is detected and when no parallel transmission of circuit and packet switched data is possible the switching center provides the presence information to the presence user entity.
• the presence service detecting unit detects network related information of the user, the interface comprising a second interface providing said network related presence information of the user to the presence server of the presence service entity.
• the ICS-enhanced switching center complements the network agent provided presence information for all ICS subscribers beyond what is available today by CAMEL. Instead of using CAMEL, the CAMEL provided presence information can also be directly provided by the ICS- enhanced switching center to the presence server. This simplifies the handling and minimizes network resource usage.
• the Pen Interface is extended such that it can directly be served by the switching center.
• the presence information detecting unit may take over the role of the presence network agent, the second interface directly providing the network related presence information to the presence server.
• a method for providing presence information of the user to the presence service entity in which the switching center detects the presence information of the user and provides the detected presence information to the presence service entity.
• user related presence information may be detected by the switching center and may be transmitted to the presence service entity via a first interface. Additionally a call status of the user can be determined and when an established call for said user has been determined the presence information is detected and provided to the presence service entity by the switching center. Furthermore it is possible that the call status of that user is determined and when an established call of said user has been determined the presence information is detected and provided to the presence service entity by the switching center.
• the presence information is detected and provided to the presence service entity by the switching center, meaning that the switching center takes over the role of the presence user agent providing the user related information to the presence proxy of the presence service entity.
• the switching center may determine a busy or idle condition of the user and may provide this information about the busy or idle condition to the presence service entity.
• the network related presence information can be transmitted to the presence service entity via the second interface.
• the switching center may determine a location information of the user and may transmit the location information to the presence service entity,
• Fig. i shows the known ICS architecture
• Fig. 2 shows the known presence information related architecture
• Fig. 3 shows the architecture of a switching center enhanced with an ICS feature according to the invention
• Fig. 4 shows a schematically view of the enhanced switching center of Fig. 3,
• Fig. 5 shows a flow chart containing the steps how the switching center works for determining whether it should provide presence information or not
• Fig. 6 shows a flow chart in case of an originating call request the switching center taking over the role of the presence user agent
• Fig. 7 shows a flow chart comprising the steps in case of a terminating call request
• Fig. 8 shows a flow chart comprising the steps when the switching center publishes the idle condition of the subscriber
• Fig. 9 shows a flow chart comprising the steps when one subscriber decides to take over the costs of the entire session
• Fig. io shows a schematic view of an ICS-enhanced mobile switching center server extending the Pen Interface
• Fig. ii shows a flow chart comprising the steps of an presence attribute indicating that the user is at home or not
• Fig. 12 shows a flow chart comprising the steps where the watchers are informed of the presence of the user at home.
• FIG. 3 a schematic view of the architecture is shown with which a presence information can be updated even when the mobile user entity, here the legacy user entity 340, cannot transmit circuit switched and packet switched data in parallel.
• An enhanced mobile switching center server 320 provides presence information and is called eMSC-S. In the embodiment shown it supports a radio interface to the user entity 340 which is assumed not to be updated with ICS functions.
• the eMSC server 320 uses the session and bearer control interface towards an IMS 310 (IP Mulitmedia Subsystem).
• IMS 310 IP Mulitmedia Subsystem
• the user entity 340 is connected via a media gateway 330 to the IMS 310.
• the user entity further has a packet switched radio access via the packet switched Pep interface to a presence service entity 200.
• the presence service entity 200 and an ICS (IMS centralized service) application server 350 interface the IMS core via an ISC interface.
• an ICS Pep Interface between the eMSC server 320 and the presence service entity 200 is provided supplying information to the presence service entity when a call is established for the user entity 340.
• the eMSC server 320 is shown in Fig. 4 in more detail.
• the eMSC server 320 comprises a call controller 321 controlling the call of the user entity 340.
• a call status determination unit 322 is provided which is adapted to determine a call status of the user.
• a presence information detecting unit 323 detects a present information of the user of the user entity 340 and a transmission status determination unit 324 determines whether, for that user, packet switched and circuit switched data transmission is possible in parallel.
• Two interfaces 325 and 326 represent the interface towards the present service entity 200. As will be explained in more detail further below, the first interface may be used to provide user related presence information to the presence service entity whereas second interface 326 is used to provide network related presence information to the presence service entity.
• the two interfaces 325 and 326 are designed as two seperate units. However, it should be understood that these two units may also be incorporated to one physical unit together with one of the other units provided in the switching center, the different functions being obtained by an appropriate processing unit and by providing instructions to the processing unit by software.
• Figs. 5 to 9 embodiments are described in which the MSC server 320 takes over the role of the presence user agent providing presence information of the user.
• Fig. 5 the provision of user related presence information by the MSC server is shown in more detail.
• the method shown starts in step 50 and in step 51 it is detected that a terminating call or originating call has to be established for the user entity 340.
• the eMSC server 320 checks the capabilities of the terminal and the radio technology used to communicate with the terminal by checking whether a packet switched connection is possible in parallel to the circuit switched connection (step 52).
• this may also be derived from operator preferences (by static O and M setting).
• step 53 If a packet switched connection is possible in parallel no further action is taken and the method ends in step 53. If, however, no parallel packet switched connection is possible the eMSC server 320 takes over the role of the presence user agent for the duration of the call (step 54). When the established call is terminated in step 55 the eMSC server 320 terminates the presence information supply via the Pep Interface 56, the method ending in step 57.
• the eMSC server 320 terminates the presence information supply via the Pep Interface 56, the method ending in step 57.
• the originating session is established towards a B-Party meaning that in a first step a setup message is sent from the user entity to the eMSC server.
• the eMSC server transmits an SIP invite messge to the CSCF where an IMS service control is initiated as shown in step 3 of Fig. 6.
• a SIP invite message is then transmitted to the B-Party which sends the OK message back to the user entity.
• the user entity is sending an connection acknowledgement message to the eMSC server in step 8. After that the eMSC server determines that it has to take over the role of the presence user agent (step 9).
• the eMSC server transmits the information that the user entity is busy to the CSCF in step 10 from where the information is transmitted to the presence server in step 11.
• the presence information is updated (step 12) and the watchers are informed in step 13, an OK message being sent back from the presence server via the CSCF to the eMSC server in steps 14 and 15 of Fig. 6.
• the eMSC server detects this information and starts to provide presence information to the presence server.
• Fig. 6 the call request was initiated by the user entity whereas in the embodiment shown in Fig. 7 the B-Party initiates the call request resulting in a terminating call request in view of the user entity 340.
• steps 1 to 12 of Fig. 7 a terminating session is established from the B-Party to the non ICS-enhanced user entity. Steps 1 to 12 are known to those of ordinary skill in the art and are therefore not discussed in detail.
• the OK message has been sent from the eMSC server 320 to the Party B in steps 10 to 12 the eMSC determines that it has to take over the presence user agent role (step 13).
• the eMSC server then informs the S-CSCF that the user entity is busy (step 14), the latter transmitting the updated information to the presence server in step 15.
• the presence server can update its presence information and can inform the watchers in step 17 before OK messages are sent to the S-CSCF and from the latter to the eMSC server in step 19.
• Fig. 8 shows the situation at the end of an ongoing session. In case a user entity terminates a call the disconnection message is sent from the user entity to the B-Party in steps i to 3.
• the CSCF takes over the IMS service control.
• the OK message is sent back to the user entity wherein the eMSC server releases the user entity in step 7, the user entity informing the eMSC of the release complete in step 8.
• the eMSC can suspend to handle the PUA role since the packet switched connection is about to be restored.
• the eMSC then publishes the idle condition of the subscriber (steps 10,11) the presence server updating the presence information about the idle condition and informing the watchers in step 13 of the idle condition.
• an OK message is sent back to the eMSC server.
• a charging related service is discussed in more detail.
• the idea of this charging-service is to give the subscriber the possibility to take over the costs of a session.
• a session is going on and Party A decides to pay for the entire session or conference call.
• Party A can decide either to take over the costs for the entire sessions or from a certain point in time onwards until the end of the session. This can also be used for conference sessions so the presence information may be updated to indicate that the served subscriber is running a conference and that admittance to this conferences is free.
• step 1 the subscriber decides to take over the costs of the entire session or conference. This can be indicated to the eMSC server by using USSD mechanisms, and forwarded to the IMS domaine using SIP options or any equivalent method (step 2).
• step 3 the CSCF takes over the IMS service control and transfers the session costs to subscriber A. CSCF sends an acknowledgement back to subscriber A in steps 4 and 5.
• the eMSC server has presently the role of the presence user agent as an established call has been detected for said user. Accordingly it has to update the presence server accordingly.
• step 6 and 7 the new payment situation is transmitted from the eMSC server to the presence server, in step 8 the presence server updating the information who is paying for the ongoing session.
• step 9 the watchers are informed accordingly, and last but not least in steps io and ii an OK message is sent back to the eMSC server.
• the mechanism that the MSC server acts as presence user agent in the case the user entity is busy can also be used for other services.
• One additional example is to provide location information to network-based applications.
• the user entity So if the user entity is idle, it provides location information related presence information directly via the packet switched connection. This location information can be based on the cell in which the user entity is currently located since the information on the current cell is available in the user entity, and the user entity based presence user agent can use this information to keep the presence information and the presence server up to date.
• the MSC server provides the cell information as presence user agent because for ongoing calls the MSC server holds the mobility info on cell level.
• the MSC server is informed by BSSMAP handover performed message about cell change within BSC (Based Station Controller) or about external handover with handover required message. Accordingly the invention can be used to keep the presence information on a consistent accuracy level also during ongoing calls.
• Fig. io an embodiment is shown with which the eMSC can provide network related information to the presence service entity.
• the architecture of this embodiment is very similar to the one shown in Fig. 3 so that a detailed discussion of entities already discussed in connection with Fig. 3 is omitted.
• the eMSC server 320 is used to extend the Pen Interface such that it can directly be served by the eMSC.
• a Pen Interface exists between the eMSC server 320 and the service entity 200. This Pen Interface complements the Pep Interface which is directly served by the user entity.
• an example of presence attribute is shown in more detail. In the embodiment shown in presence attribute is called "I am home" and "I'm at work”.
• the user of this presence attribute has the possibility to mark a certain location with the attribute " I am at home” and another location with the attribute "I am at work”. This can be done by using, for example, a pre-defined USSD string which the subscriber sends of a particular location which shall be marked.
• the eMSC server 320 then stores the current location area, the LAI or SAI, (location area indicator or surface area indicator) when the USSD string is received. As shown in Fig. 11 in case the user is located at a particular location he wants to mark as home location the USSD string is sent to the eMSC server in step 1 the eMSC server determining the current location (step 2).
• the eMSC server then monitors the roaming of the subscriber and each time the subscriber enters one of the stored location areas the eMSC server updates the present information towards the server to indicate "I am home" (step 3). In step 4 an USSD string (acknowledgement) is sent back to the user entity.
• the MSC server checks each time whether the user entity has entered a marked area (steps 2 and 3). If this is the case, a location update acceptance message is sent to the user entity in step 4 and the information that the subscriber is at home is sent to the presence server in step 5, the latter updating the presence information and informing the watchers in step 6 and 7. In step 8 the OK message is sent back to the eMSC server.
• this service could also be realised by the user updating his own presence profile each time he comes home or enters work. But as this usually happens quite often it is very cumbersome to do so and is very likely forgotten. This would render the presence information unreliable.
• This service could also be realised using CAMEL mobility notifications. However, this consumes more network resources since CAMEL mobility triggers only support the reporting of every relocation update but not a location update into a specific area. Thus a seperate service mode would have to receive all notifications related to location update events and then filter out the ones into the home location area in order to achieve the same service behaviour. This would produce clearly much more load and is much more difficult to implement and run in a real network.
• Simpler service implementation is obtained since the presence information can be provided via the Pep Interface from the eMSC server instead of using complicated CAMEL network, and network resources. Furthermore it is possible to provide additional presence information which would not be available via CAMEL interfaces due to limitations on the interface.

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• 2009
  • 2009-01-29 WO PCT/EP2009/050975 patent/WO2009149963A1/en active Application Filing
  • 2009-01-29 EP EP09761526A patent/EP2301223A1/de not_active Withdrawn

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