KR20110014897A - 2g mobile communication system supporting service centralized and continuity and method thereof - Google Patents

2g mobile communication system supporting service centralized and continuity and method thereof Download PDF

Info

Publication number
KR20110014897A
KR20110014897A KR1020090072493A KR20090072493A KR20110014897A KR 20110014897 A KR20110014897 A KR 20110014897A KR 1020090072493 A KR1020090072493 A KR 1020090072493A KR 20090072493 A KR20090072493 A KR 20090072493A KR 20110014897 A KR20110014897 A KR 20110014897A
Authority
KR
South Korea
Prior art keywords
scc
call
terminal
location registration
domain
Prior art date
Application number
KR1020090072493A
Other languages
Korean (ko)
Inventor
황진호
Original Assignee
주식회사 케이티
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 주식회사 케이티 filed Critical 주식회사 케이티
Priority to KR1020090072493A priority Critical patent/KR20110014897A/en
Publication of KR20110014897A publication Critical patent/KR20110014897A/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W4/00—Services specially adapted for wireless communication networks; Facilities therefor
    • H04W4/16—Communication-related supplementary services, e.g. call-transfer or call-hold
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W40/00—Communication routing or communication path finding
    • H04W40/02—Communication route or path selection, e.g. power-based or shortest path routing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/10—Connection setup
    • H04W76/12—Setup of transport tunnels
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W8/00—Network data management
    • H04W8/02—Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
    • H04W8/04—Registration at HLR or HSS [Home Subscriber Server]

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Databases & Information Systems (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

A mobile communication system supporting the SCC and a method thereof are provided. A mobile communication system supporting SCC includes a subscriber location register providing service call continuity (SCC) routing information for a called terminal, a 2G switching center that routes a call using SCC routing information when a call is requested to the called terminal. Call session control function for attempting to establish a session with a destination terminal, and an SCC application server for determining a destination domain to service a routed call.

SCC, 2G, Exchange

Description

Mobile communication system supporting SCC and method thereof 2G Mobile Communication System supporting Service Centralized and Continuity and Method

The present invention relates to a mobile communication system, and more particularly, to a Service Centralized and Continuity (SCC) in a 2G mobile communication system.

In the 3G mobile communication system, the SCC is a mobile terminal used for a general CS (Circuit Switched) domain connected through a Universal Terrestrial Radio Access Network (UTRAN), a GSM DEGE Radio Access Network (GERAN), or an IP Multimedia Subsystem (IMS). It provides domain selection to connect a call through either the CS domain or the IMS domain, and transfers the domain to pass the connected call to another system according to the condition. This can increase the coverage of the wireless service and, in particular, can route some calls to the wireless network, i.e., the IM core network subsystem, thereby reducing the load on the mobile communication network.

Unlike 3G mobile communication systems, 2G mobile communication systems do not support call processing between an exchange and a VSS AS (Application Server). In the 3G mobile communication system, a procedure for processing a suitable outgoing call originated by the SCC terminal through either the CS domain or the IMS, a call termination procedure, and a call switching procedure between communication systems are defined. However, in order to apply this to 2G mobile communication systems, a call processing procedure for connecting an outgoing call from an exchange to an SCC AS is required.

An object of the present invention is to propose a call processing procedure for implementing the SCC function in a 2G mobile communication system. That is, by enabling the use of the ICC SCC in the 2G mobile communication system, it is possible to provide a FMC (Fixed Mobile Convergence) based Seamless service.

According to an aspect of the present invention, a subscriber location register for providing Service Centralized and Continuity (SCC) routing information for a called terminal; A 2G switching station that routes the call using the SCC routing information when a call is requested to the called terminal; A call session control function for attempting to establish a session with the called terminal by a routed call; And an SCC application server for determining a destination domain to service the routed call.

According to another aspect of the invention, if the location registration request from the user terminal, transmitting a location registration request for the user terminal to the subscriber location register; Receiving a location registration response including Voice Centralized and Continuity (SCC) routing information in response to the location registration request; And requesting a location registration to an SCC application server through an IMS domain using the SCC routing information, and a method for implementing an SCC function in a 2G mobile communication system and a recording medium storing a program implementing the method are provided. .

According to the present invention, the SCC function can be implemented in a 2G mobile communication system. Through this, the 2G mobile communication system can provide a FMC (Fixed Mobile Convergence) based seamless service by using the SCC of IMS.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, when it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate a thorough understanding of the present invention, the same reference numerals are used for the same means regardless of the number of the drawings.

1 is a block diagram showing a mobile communication system supporting the SCC according to an embodiment of the present invention. Referring to FIG. 1, a mobile communication system supporting SCC includes an exchange station 120, a subscriber location register (HLR) 30, a media gateway control function 140, and a call session control function. 150 and a Service Centralized and Continuity (SCC) application server 160.

The user equipment 110 is a user device for using a mobile communication service. The user terminal 110 is a calling terminal, which is a 2G terminal capable of using a service in a CS (Circuit Switched) domain according to a 2G mobile communication system. The called terminal to which the user terminal 110 attempts to call is a 3G terminal that can use a service in a PS (Packet Switched) domain (or IMS domain) according to the 3G mobile communication system.

According to 3GPP TS 23.292, which defines the SCC of the 3G mobile communication system, the terminating terminal has no special requirements for registering as an SCC UE in the IMS to use the SCC, and in both the CS (Circuit Switched) domain and the IMS domain It is sufficient to be able to carry out the outgoing call procedure and the call termination procedure.

Switching station 120 obtains a subscriber profile for the user terminal 110 from subscriber location register 130 according to the location registration request of user terminal 110, and if the SCC service subscription terminal location registration to the CS domain and IMS A location registration procedure to the SCC application server 160 through the domain is performed. The location registration procedure of the switching center 120 will be described in more detail with reference to the accompanying drawings below.

The 2G switching center interworks with the subscriber location register 130 but does not support the CAMEL protocol interworking with the SCC application server 160. Accordingly, routing to the SCC application server 160 is enabled through parameters provided from the subscriber location register 130. Switching station 120 performs the general call processing procedure according to the 2G standard. Since the 2G switching center 120 does not support SCC, the originating call is routed to the SCC application server 160 only when information necessary for routing to the SCC application server 160 (hereinafter referred to as SCC routing information) is obtained. When the exchange 120 receives the outgoing call, it checks the subscriber location register of the GT (Global Title) through the translation of the incoming prefix number. The exchange station 120 inquires the location information of the called terminal in the confirmed subscriber location register 130 and routes it to the other switching station where the called terminal is located according to the result.

The subscriber location register 130 manages information about services subscribed to by the user terminal 110 and location information of mobile terminals. Subscriber location register 130 provides routing information to switching center 120. The subscriber location register 130 manages information about services subscribed to by the user terminal 110 and location information of mobile terminals. If the user terminal 110 is subscribed to the SCC service, the subscriber location register 130 provides the SCC routing information to the switching center 120. Unlike the 3G mobile communication system, since the 2G mobile communication system does not support the SCC, the subscriber location register 130 checks whether the switching center requesting the location information request for the called terminal belongs to the 2G mobile communication system to selectively select the SCC routing information. You can also provide. The SCC routing information is included in the location information response in the form of a MAP message and delivered.

Media gateway control function 140 provides protocol conversion between ISUP and IMS call control protocol. The media gateway control function 140 makes an ISUP connection with the switching center 120 belonging to the CS domain, and selects the call session control function 150 to route the incoming call to the IMS domain. According to the SCC standard defined in the 3G mobile communication system, the media gateway control function 140 must support signaling interworking and media control between the CS domain and the IMS domain.

The call session control function 150 performs voice call processing in the IMS domain. The call session control function 150 is composed of an Interrogate-CSCF (I-CSCF), a Proxy-CSCF (P-CSCF), and a Serving-CSCF (S-CSCF). I-CSCF provides routing information so that call request messages are delivered to the appropriate server within the IMS domain. P-CSCF is a point where a user terminal meets when accessing an IMS domain through an access network. The P-CSCF forwards a SIP Registration Request from the user terminal to the I-CSCF. The S-CSCF establishes a call session and plays a role of receiving and processing a Session Initiation Protocol (SIP) message transmitted from a user terminal.

SCC application server 160 provides a domain selection and domain transfer function. The SCC application server 160 is responsible for anchoring for outgoing calls delivered from the CS domain, anchoring for outgoing calls delivered from the IMS domain, and domain switching. By anchoring, information about an outgoing call (Call ID) and user identification information (Public User Identity) is stored. To this end, all calls from the user terminal subscribed to the SCC service is transmitted to the SCC application server 160. However, since the exchange did not support the SCC service for the outgoing call requested from the 2G mobile communication network that does not support the SCC, the user terminal could not use the SCC service. The SCC application server 160 supports Message Exchange Patterns (MEP) for information exchange.

2 is a diagram illustrating a location registration procedure in a mobile communication system supporting an SCC according to an embodiment of the present invention. Here, the terminal requesting location registration is a 2G terminal as a calling terminal. In FIG. 2, a location registration procedure of an originating terminal to an SCC application server 160 supporting SCC through a CS domain will be described.

When the location registration is requested from the calling terminal (S210), the switching center 120 transmits a location registration notification message (REGNOT) to the subscriber location register 130 for location registration of the calling terminal according to the location registration request of the calling terminal ( S215). The subscriber location register 130 stores the location for the calling terminal according to the location registration notification message of the switching center 120. The subscriber location register 130 checks whether the subscriber of the calling terminal subscribes to the SCC service and subscribes to the SCC service, and registers a location registration notification response message (REGNOT Return Result) including the SCC subscription information and the SCC routing information. It transmits to the switching center 120 (S220).

Here, the parameter of the location registration notification response message is a MAP message using the TCAP parameter defined in ANSI T1.114. The location registration notification response message includes a Calling Feature Indicator2 parameter and a RoutingDigits parameter. The Calling Feature Indicator2 parameter indicates subscription information of a specific service or call, and the RoutingDigits parameter indicates special routing information. In this embodiment, the Calling Feature Indicator2 parameter indicates SCC subscription information, and the RoutingDigits parameter indicates information about a routing destination to the SCC application server 160.

The switching center 120 checks whether the SCC subscription information is included in the location registration notification response message (S225). If the location registration notification response message includes the SCC subscription information and SCC routing information, the switching center 120 obtains and stores the SCC subscription information and SCC routing information in the location registration notification response message. Of course, the switching center 120 stores the SCC subscription information and the SCC routing information obtained in a VLR (not shown) interworking with the switching center 120. If the location registration notification response message does not include the SCC subscription information, the switching center 120 performs a general location registration procedure.

However, if the SCC information is included in the location registration notification response message, the switching center 120 performs the location registration procedure to the SCC application server 160 through the IMS domain using the obtained SCC routing information.

If the calling terminal is subscribed to the SCC service (i.e., the SCC information is included in the Calling Feature Indicator2 parameter), the switching center 120 sends an IAM message (initial address message) to the media gateway control function 140 using the SCC information. Transmit (S230). The IAM message is initiated to occupy the relay line between the switching center 120 and the media gateway control function 140. The IAM message delivers information necessary for signal processing and routing with the media gateway control function 140 using the ISUP parameter. The ISUP parameter includes a UUI parameter including subscriber information. The switching center 120 includes the SCC information in the UUI parameter and transmits it to the media gateway control function 140.

If the SAM information is included in the IAM message, the media gateway control function 140 is a session initiation protocol (SIP) destined for the SCC application server 160 as a call session control function 150 in charge of call processing in the IMS domain. ) REGISTER message is transmitted (S240). The SIP REGISTER message includes identification information of the subscriber station and SCC routing information. The call session control function 150 receiving the SIP REGISTER message relays it to the SCC application server 160.

3 is a diagram illustrating a call processing procedure of a mobile communication system supporting an SCC according to an embodiment of the present invention, and relates to a call processing procedure at an originating switching center. Here, the calling terminal 110 requesting a call is a 2G terminal, the called terminal requesting a call is a 3G terminal, and the called terminal has a location registered in at least one of a CS domain or an IMS domain. In addition, the originating terminal 110 is a state registered in the SCC application server 160 of the IMS domain through the CS domain.

When an outgoing call to the called terminal is requested from the calling terminal 110 (S310), the calling party switching station 120 determines whether the subscriber of the calling terminal 110 is subscribed to the SCC service (S315). As described with reference to FIG. 2, when the subscriber of the calling terminal 110 is subscribed to the SCC service, the 2G switching center 120 receives the SCC information and the SCC routing information according to the location registration request of the calling terminal 110. The location registration is performed from the location register 130 and the SCC application server 160 via the IMS domain. The SCC information and the SCC routing information obtained in this process are stored in the originating switching center 120. Accordingly, the calling exchange switching station 120 may check whether the subscriber of the calling terminal 110 is subscribed to the SCC service using the SCC information.

If the subscriber is a subscriber subscribed to the SCC service, the source switching center 120 checks the SCC routing information (SCRN: SCC Routing Number) (S320), and the IAM to the media gateway control function 140 using the SCC routing information. The message is transmitted (S325).

Upon receiving the IAM message, the media gateway control function 140 transmits a SIP INVITE message destined for the SCC application server 160 to the call session control function 150 in charge of call processing in the IMS domain (S330). . The SIP INVITE message includes identification information of the subscriber station and identification information of the called terminal included in the IAM. The call session control function 150 receiving the SIP INVITE message relays it to the SCC application server 160 (S335).

Receiving the SIP INVITE message, the SCC application server 160 determines the destination domain to service the outgoing call (S340). The destination terminal may register the location in either the CS domain or the IMS domain, or may simultaneously register the location in both domains. Therefore, the SCC application server 160 checks the domain registered by the destination terminal to the current location to ensure that the service is provided through the domain. After the domain determination is completed, the SCC application server 160 performs a procedure for connection of the outgoing call to the called terminal. SCC application server 160 transmits the SIP INVITE message to the call session control function 150 and requests to establish a service call with the called terminal (S345), whereby the call session control function 160 is a service call to the called terminal The SIP INVITE message requesting the setting is transmitted (S350).

4 is a diagram illustrating a call processing procedure of a mobile communication system supporting an SCC according to an embodiment of the present invention, and relates to a call processing process at a destination switching center. Here, the called terminal requesting a call is a 3G terminal, and the called terminal has a location registered in at least one of a CS domain and an IMS domain.

When the incoming call is requested from the other network or the originating exchange to the called terminal (S410), the called side exchange 120 determines whether the called terminal is an SCC service subscriber. As described with reference to FIG. 2, the called terminal and the calling terminal each perform location registration while being located in the CS domain. In this case, when each of the called terminal and the calling terminal is subscribed to the SCC service, after performing location registration in the CS domain, location registration to the SCC application server 160 is also performed through the CS domain. In this process, each switching center 120 obtains SCC information and SCC routing information from the subscriber location register 130 and stores the SCC information and SCC routing information in the VLR linked to each switching center 120.

Therefore, when the called party to the destination terminal 120 is called, the called terminal stored in the switching center 120 is subscribed to the SCC service by using the SCC information and the SCC routing information stored when the destination terminal is registered. Check whether there is (S415). If the terminal is subscribed to the SCC service, the destination switching center 120 extracts the SCC routing information corresponding to the destination terminal (S420), and transmits the IAM to the media gateway control function 140 using the extracted SCC routing information. (S425). By the IAM, the occupation of the relay line between the destination switching center 120 and the media gateway control function 140 is started, and information necessary for signal processing and routing is transmitted. Here, the information necessary for path setting includes identification information of the subscriber station, identification information of the originating terminal, and SCC routing information.

Upon receiving the IAM, the media gateway control function 140 transmits a SIP INVITE message destined for the SCC application server 160 to the call session control function 150 in charge of call processing in the IMS domain (S430). The SIP INVITE message includes identification information of the subscriber station and identification information of the calling terminal included in the IAM. The call session control function 150 receiving the SIP INVITE message relays it to the SCC application server 160 (S435).

Upon receiving the SIP INVITE message, the SCC application server 160 determines the domain in which the subscriber station 10 is serving (S440). The domain is either a CS domain or an IMS domain. After the domain determination is completed, the SCC application server 160 performs a procedure for the incoming call connection to the subscriber station (10). If the SCC application server 160 sends a SIP INVITE message to the call session control function 150 to notify which domain the subscriber station 10 is in service, and requests to establish a voice call with the subscriber station (S445), As a result, the call session control function 60 transmits a SIP INVITE message requesting voice call setup to the subscriber station (S450).

On the other hand, the call processing method of the mobile communication system supporting the SCC according to an embodiment of the present invention may be implemented in the form of program instructions that can be executed through various electronic means for processing information may be recorded in the storage medium. The storage medium may include program instructions, data files, data structures, etc. alone or in combination.

The program instructions recorded in the storage medium may be those specially designed and constructed for the present invention, or may be known and available to those skilled in the software art. Examples of storage media include magnetic media such as hard disks, floppy disks and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic-optical media such as floppy disks. hardware devices specifically configured to store and execute program instructions such as magneto-optical media and ROM, RAM, flash memory, and the like. In addition, the above-described medium may be a transmission medium such as an optical or metal wire, a waveguide, or the like including a carrier wave for transmitting a signal specifying a program command, a data structure, and the like. Examples of program instructions include not only machine code generated by a compiler, but also devices that process information electronically using an interpreter, for example, high-level language code that can be executed by a computer.

The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

1 is a block diagram showing a mobile communication system supporting the SCC according to an embodiment of the present invention.

2 is a diagram illustrating a location registration procedure in a mobile communication system supporting an SCC according to an embodiment of the present invention.

3 is a diagram illustrating a call processing procedure of a mobile communication system supporting an SCC according to an embodiment of the present invention.

4 is a diagram illustrating a call processing procedure of a mobile communication system supporting an SCC according to an embodiment of the present invention.

Claims (8)

A subscriber location register for providing Service Centralized and Continuity (SCC) routing information for a called terminal; A 2G switching station that routes the call using the SCC routing information when a call is requested to the called terminal; A call session control function for attempting to establish a session with the called terminal by a routed call; And A mobile communication system comprising an SCC application server for determining a destination domain to service a routed call. The method of claim 1, And a media gateway control function for relaying a call routed from the switching center to the call session control function. The method according to claim 1 or 2, The SCC routing information is included in a location registration response to a location registration request of the calling terminal or the called terminal of the switching center. The method of claim 3, And when the location registration response includes the SCC routing information, requesting location registration for the originating terminal or the destination terminal by using the SCC routing information as the destination. If a location registration is requested from a user terminal, transmitting a location registration request for the user terminal to a subscriber location register; Receiving a location registration response including Service Centralized and Continuity (SCC) routing information in response to the location registration request; And Requesting location registration to an SCC application server through an IMS domain using the SCC routing information. 6. The method of claim 5, If a call is requested to a called terminal, routing the call to a call session control function using SCC routing information included in the location registration response; Determining a called domain in use by the called terminal; And And establishing a session with the called terminal located in the called domain determined by the routed call. The method according to claim 5 or 6, The user terminal is a method for implementing the SCC function in a 2G mobile communication system that is a destination terminal or originating terminal. The method according to claim 6, The destination domain is a method of implementing a SCC function in a 2G mobile communication system of any one of the CS (Circuit Switched) domain or IP Multimedia Subsystem (IMS).
KR1020090072493A 2009-08-06 2009-08-06 2g mobile communication system supporting service centralized and continuity and method thereof KR20110014897A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020090072493A KR20110014897A (en) 2009-08-06 2009-08-06 2g mobile communication system supporting service centralized and continuity and method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020090072493A KR20110014897A (en) 2009-08-06 2009-08-06 2g mobile communication system supporting service centralized and continuity and method thereof

Publications (1)

Publication Number Publication Date
KR20110014897A true KR20110014897A (en) 2011-02-14

Family

ID=43773884

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020090072493A KR20110014897A (en) 2009-08-06 2009-08-06 2g mobile communication system supporting service centralized and continuity and method thereof

Country Status (1)

Country Link
KR (1) KR20110014897A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8782720B2 (en) 2011-06-30 2014-07-15 Electronics And Telecommunications Research Institute Method and system for synchronizing content between terminals

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8782720B2 (en) 2011-06-30 2014-07-15 Electronics And Telecommunications Research Institute Method and system for synchronizing content between terminals

Similar Documents

Publication Publication Date Title
US10932321B1 (en) Method of providing data, voice, and SMS services to LTE subscribers roaming in 2G/3G visited networks
CN101573996B (en) Method and apparatus for allowing session control of ims services via a cs access by ussd messages
EP1920572B1 (en) Multimedia subsystem service control for circuit-switched subsystem calls
EP2030471B1 (en) Call delivery to a dual mode wireless device
RU2389142C1 (en) Mobile communication method and system for transmitting information, relating to network capabilities
US7953072B2 (en) Method and system for ending-call anchoring of circuit switched domain
KR101565626B1 (en) A mobile switching center platform having interfaces with functionalities defined by an architecture that provides packet-switched multimedia subscriber services
EP2073479A1 (en) Method and system for call continuity
US20130308632A1 (en) Routing terminating calls
CN103703737A (en) Methods and apparatus for supporting the implementation of ims service continuity
CA2661907C (en) A system and method for implementing an original call anchoring in voice call continuity service
US20090129318A1 (en) Method, system and application server for routing cs domain calls to ps domain
US8289887B2 (en) Late call forwarding method in IP multimedia core network subsystem centralized service
US9131042B2 (en) Method for handling CS calls in voice call continuity, VCC application server and translation entity
CN102883376A (en) Method, server and system for establishing priority session for centralised controlled service user
CN106937264B (en) VoLTE user call addressing method, system and HSS
CN101217795B (en) A settlement method of the local transferring of the terminal in IP multimedia subsystem
GB2440987A (en) Synchronising network services between CS and IMS domains
KR20110014897A (en) 2g mobile communication system supporting service centralized and continuity and method thereof
EP2040508A1 (en) Method, apparatuses and program product for controlling IMS services when user is roaming in CS domain
CN101217797B (en) A realization method of call starting in IP multimedia subsystem centralized control operation
KR101617776B1 (en) Mobile Communication System and Method for processing supplementary service
KR102286082B1 (en) Vioce call service swiching system, gateway apparatus and service swiching apparatus and control method each of them
KR20100118902A (en) 2g mobile communication system supporting voice call continuity and method thereof
CN108616829B (en) Method for domain selection, service centralization and continuity application server and system

Legal Events

Date Code Title Description
WITN Withdrawal due to no request for examination