Architecture of mobile communication systems network and method for transmitting packet data using the same

Architecture of a mobile communication system network and method for transmitting a packet data using the same, which can minimize required signal links and interlocking lines, the architecture including a plurality of radio network controllers each connected to a plurality of base stations in a cell or a sector to which the network controller pertains for separating a packet data service path from a circuit data service path when a particular mobile station is matched to this core network, at least one mobile switching center connected to the plurality of radio network controllers in a region of the mobile switching center by an ATM switching system for routing an originating call from the mobile station or a terminating call to the mobile station, a VLR/HLR(Visitor location register/home location register) connected to the mobile switching center for managing mobility of the mobile stations, and at least one PDGN(Packet data gateway node) for routing a packet data provided from either the mobile switching center or an external network according to a terminating call side identification number.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mobile communication system, and more particularly, to an architecture of a mobile communication system network which can make connection to the Internet/a packet network from a mobile station, transmit a signal received from the Internet/the packet network to a moving mobile station, or support data communication between mobile stations; and a method for transmitting a packet data using the same.

2. Background of the Related Art

First generation terrestrial radio data communication uses an exclusive radio data communication network or a cellular communication system provided with a modem. On the other hand, second generation terrestrial radio data communication uses combined speech/data radio data communication employing digital cellular/PCS network. In the next generation communication, it is foreseen that there will be ceaseless development of high speed radio data services in a multimedia information based communication environment. That is, in place of exclusive speech or data communication service, multimedia service of, such as speech, data, text and image based on radio mobile communication service will be on the lead. Under this situation, the next generation mobile telephone system(IMT-2000) based on the cellular/PCS radio communication system network defines a communication system network such that a radio terminal can even provide a wideband multimedia service, studies for standardizing which is underway. For the success of global roaming service, high speed radio data service, and radio multimedia service, which are basic system requirements for the next generation mobile communication network, interlock both with the Internet, which makes global service, and a packet data communication system network is an essential requirement as set forth in the standard document(Q. 1701) of the ITU(International Telecommunications Union), presently. A draft for formulating a communication system network to implement such interlock with the Internet/packet network is suggested in the standard document Q. 1701 of the ITU.

FIG. 1illustrates a block diagram of a related art mobile communication system network suggested in the ITU standard documents Q. 1701 and Q. 1711.

Referring toFIG. 1, one user data terminal UDT1or UD12and one mobile terminal MT1or MT2connected together form a mobile station MS1or MS2for providing a radio Internet and a packet data services. Each base station BS1-BS3connects the mobile station MS1or MS2to a radio channel. Each of radio network controllers RNC1and RNC2is connected to a plurality of base stations BS1and BS2within a cell or a sector to which it pertains for separating packet data and circuit data service paths in matching with a core network using a channel assignment function varied with an service option of the mobile stations MS1or MS2. A packet data serving node PDSN1or PDSN2is a physical element having a PSCF(Packet service control function) defined in the ITU standard document Q1711. And, a PDGN (Packet data gateway node) is a physical element having a PSGCF(Packet service gateway control function). The PDSN and the PDGN are radio packet data service elements, for transmitting a packet data, which is to be transmitted from the UDT (UDT1or UDT2) to the Internet/packet network300, from the RNC (RNC1or RNC2) to the Internet/packet network300by packet switching. Since the PDSNs (PDSN1and PDSN2) and the PDGN should always know positional movements of the mobile terminals MT1and MT2for switching a packet data, the PDSNs (PDSN1and PDSN2) and the PDGN should have a signal line always connected to VLR/HLR(Visitor location register/home location register) and maintained. Therefore, in order to support a roaming service for a mobile station roamed into other communication company and a hand off service, the PDGN in a home network and the PDSN in a visit network should be connected with an NNI(Network to network interface).

However, the related art mobile communication system network has the following problems.

First, in the mobile communication system network as shown inFIG. 1, a continuous maintenance of a signal link between the PDSN and the PDGN is prerequisit for connection to the Internet/packet network from a particular mobile station. That is, when a mobile station executes hand-off frequently, either the PDSN in the home network and the PDSN in the visit network should be connected, or the PDGN in the home network and the PDSN in a visit network should be connected. Eventually, the packet data transmission under such communication environment causes complicated tangling of communication system networks.

Second, the requirement for registration of positional information of a mobile station roamed from a home network to a visit network on the VLR/HLR causes signal traffic between the PDSN and the VLR/HLR or the PDGN and the VLR/HLR every time a position registration or position verification is executed.

Third, as shown inFIG. 1, connection both of the PDSN and the PDGN to the VLR/HLR is required for implementing a mobile station position registration, which can not but greatly increase signal links for position registration or position verification of mobile stations if a plurality of PDSNs and/or PDGNs are operative in the communication system network shown inFIG. 1, that requires additional matching devices provided separately to the VLR/HLR for reduction of the increased communication links in the related art.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an architecture of a mobile communication system network and a method for transmitting a packet data using the same that substantially obviates one or more of the problems due to Limitations and disadvantages of the related art.

An object of the present invention is to provide an architecture of a mobile communication system network and a method for transmitting a packet data using the same, which can minimize required signal links and interlocking lines.

Other object of the present invention is to provide an architecture of a mobile communication system network and a method for transmitting a packet data using the same, which facilitates connection to the Internet/packet network from a mobile station, transmission of a signal received from the Internet/packet network to a moving mobile station, or supporting data communication between mobile stations.

Another object of the present invention is to provide an architecture of a mobile communication system network and a method for transmitting a packet data using the same, in which a particular mobile station can designate a particular PDGN directly for conducting a packet data service.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the architecture of a mobile communication system network includes a plurality of radio network controllers each connected to a plurality of base stations in a cell or a sector to which the network controller pertains for separating a packet data service path from a circuit data service path when a particular mobile station is matched to this core network, at least one mobile switching center connected to the plurality of radio network controllers in a region of the mobile switching center by an ATM switching system for routing an originating call from the mobile station or a terminating call to the mobile station, a VLR/HLR(Visitor location register/home location register) connected to the mobile switching center for managing mobility of the mobile stations, and at least one PDGN(Packet data gateway node) for routing a packet data provided from either the mobile switching center or an external network according to a terminating call side identification number.

In other aspect of the present invention, there is provided a method for transmitting a packet data in a mobile communication system network at least one radio network controller and position register and at least one PDGN, which are connected respectively in an ATM switching system centered on one mobile switching center, including the steps of (1) establishing a PPP link using a protocol stack having multiple layer between the particular radio network controller and the packet data node in response to a call connection request signal from the Internet or a packet network connected to the PDGN provided from an originating call side mobile station, (2) transmitting the packet data provided from the originating call side mobile station to the mobile switching center using the established link, and (3) the mobile switching center routing the packet data according to an identification number of a terminating call side PDGN included in the packet data.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The present invention can provide a radio data service suggested in the IMT-2000 network200based on a packet network interlock connection service, such as an Internet connection or X.25, the same as the variety of application services available in a wire network.FIG. 2illustrates a block diagram of a mobile communication system network in accordance with a preferred embodiment of the present invention.

Referring toFIG. 2, the mobile communication system network in accordance with a preferred embodiment of the present invention includes a plurality of mobile stations MS11and MS12each having a user data terminal UDT11or UDT12for providing a data communication function and a mobile terminal MT11or MT12for providing a radio connection function with a serving base station, both are connected to each other, a plurality of base stations BS11-BS13each for making a radio channel connection to the mobile terminals MT11and MT12, a plurality of radio network controllers RNC11and RNC12each connected to a plurality of base stations BS11-BS13in a cell or sector to which the radio network controller pertains for separating a packet data service path from a circuit data service path in matching a core network using a channel assignment function in a service option of the mobile station MS11and MS12, a mobile switching center MSC of ATM switch type connected to a plurality of radio network controllers RNC11-RNC13in a cell or a sector to which the mobile switching center MSC pertains for routing an originating call from the mobile station MS11or MS12or terminating call to the mobile station MS11or MS12, a VLR/HLR(Visitor location register/home location register) connected to the mobile switching center MSC for managing mobility of the mobile stations MS11and MS12, and a packet data gateway node for routing a packet data provided from either the mobile switching center or an external network according to an identifier included in the packet data. The mobile switching center MSC includes a communication network100having a PSTN(Public switched telephone network), a PCS(Personal communication system), PLMN(Public Land Mobile Network) and a B-ISDN (Broadband integrated services digital network), and an IMT-2000 network200connected thereto, and the PDGN includes the Internet/packet network300connected thereto. The PDGN and the Internet/packet network300may be connected with the Ethernet, a frame relay, or X.25 as the case demands. The PDGN and the mobile switching center MSC may be connected with a UNI(User Network Interface) in the B-ISDN. In the aforementioned communication system network, a packet data is transmitted from one user data terminal UDT11or UDT12to the PDGN on a data path set up in PPP(Point to Point) link. In this instance, the mobile switching center transmits the packet data received from the radio network controller RNC11or RNC12to the PDGN through the set up PPP link. The PPP is a link type used in the RFC 1661 serial link communication. Different from communication between terminals within an LAN or a packet switching network, since a packet data communication within the IMT-2000 network200, such as a communication between particular mobile station MS11and PDGN or between particular mobile stations MS11and MS12is a serial communication using a single path system of PPP, the packet data communication within the IMT-2000 network200is deemed optimal as a link layer protocol which connects both ends. And, in the present invention, preferably a dial up system is adapted to use an IPCP(PPP Internet Protocol Control Protocol) which conducts an IP assignment, and a link layer between the mobile station MS11and the PDGN is set up by connecting to LCP(PPP Link Control Protocol).

All the mobile terminals MT11and MT12in the mobile communication system network shown inFIG. 1should be provided with a terminal identifier for use in call connection to a circuit switching system expected to be used in basic speech communication services and multimedia communication services and a user data terminal identifier for an interlock call connection to an existing Internet packet network. That is, all the mobile terminals MT11and MT12should be assigned of an MIN(Mobile identification number) applicable to a general circuit switching network as a basic terminal identifier and should be selectively assigned of an Internet IP address or a packet address of a packet network as an SMIN(Supplementary mobile identification number) for a data. All terminating calls from all mobile stations MS11and MS12arrived to the PDGN from the Internet/packet network300are transferred to the mobile switching center MSC. Then, the mobile switching center MSC confirms a location of the mobile station through the VLR/HLR and sets up a transmission path of the packet data. Therefore, in the communication system network of the present invention, no more direct connection of the PDGN to the VLR/HLR required in the related art communication system network is required. Though the IMT-2000 network200inFIG. 2may be deemed to be a radio network built up to a broadband communication network by itself, it acts as a wireless access network in view of interlock with the Internet/packet network300. In this instance, a data path between the user data terminal and the PDGN is set up only in end-to-end as a serial communication circuit. Accordingly, as shown inFIG. 2, the PDSNs are removed, and the mobile switching center MSC is connected to the VLR/HLR, permitting to provide a simple communication system network with reduced signal traffic.

Moreover, the mobile communication system network of the present invention may be managed such that either the PDGN shown inFIG. 2is connected to a plurality of mobile switching center MSC not shown inFIG. 2or a plurality of PDGN not shown inFIG. 2is connected to one mobile switching center MSC. Thus, the mobile communication system network of the present invention can be varied to suit to a communication situation. Since one wired communication system subscriber for the Internet/packet network300can only call a particular mobile station MS11at the SMIN for data assigned from the mobile communication system network, the PDGN is taken as a subnetwork representing a data network the user data terminal UDT11with the SMIN belongs thereto or as a packet network node, and, in view of the user data terminal UDT11, a home network for data of the user data terminal is the mobile switching center MSC having the PDGN connected thereto, of which SMIN address represents a data network. In the mobile communication system network of the present invention, as the VLR/HLR having the MIN registered thereon also manage the SMIN, the data communication network and the speech and multimedia service home network are always identical.

A method for transmitting a packet data using a mobile communication system network for providing various radio data service based on the aforementioned mobile communication system network will be explained.

Internet/Packet Network Connection Service

A particular mobile station may call at and make connection to an Internet or a packet data communication system network remotely, to make connection to an Internet server or a data base in a host computer connected to the packet network. Such a connection service can be made available by providing a radio data transmission function and a gateway function corresponding to a dial-up PPP service function and a PAD(Packet assembly de-assembly) service function of a wired network to a mobile communication system of the present invention. As such a connection service is a call to a host or server in the packet network from the mobile station, a temporary IP address may be assigned for making communication. In this instance, an IP address for SMIN of the user data terminal is not required.

Internet Protocol Service by Mobile Station

A particular mobile station, not only can make a call to the Internet using an IP address for an SMIN, a user data terminal identifier and be provided with various application services, even if the mobile station is moving, but also, acting as a host, allows an Internet user to make call at a permanently assigned SMIN IP address of the user data terminal therein for being provided with various application services. This protocol service is made available as the IMT-2000 network200provides a function for supporting an IP mobility of the mobile station.

Packet Data Services Between Mobile Stations

The aforementioned two services are on data communications between a mobile station and a stationary data terminal. However, it is foreseen that radio data communications between mobile stations will be required inevitably provided that communication services based on an actual radio data communication and the IMT-2000 network become active. Therefore, a data communication protocol should be supported for supporting the radio data communications between mobile stations, effectively. In an embodiment of the present invention, a data communication call between mobile stations are made using the SMIN. In this instance, no circuit switching system is used, but a packet switching system is used, for improving an allowable number of a radio communication service subscriber in a base station. A radio data communication call or connection between mobile stations(MT/UDTs) can be made possible by calling at the SMIN or MIN using an APPL or AI layer of the mobile station(MT/UDTs) of the mobile station shown in FIG.3. In this instance, the PDGN is not involved, but the radio network controller and the mobile switching center MSC on an originating mobile station(MT/UDT) side and the radio network controller and the mobile switching center MSC on a terminating mobile station(MT/UDT) side are only involved.

PDGN Designation Service

A PDGN designation service is provided in a mobile communication system network having a plurality of PDGNs provided thereto, in which a particular user data terminal UDT may directly designate a particular PDGN for calling a desired subscriber. Irrespective of an entire mobile communication system network shown inFIG. 1or2, this service is available from all communication system networks provided with a plurality of PDGNs. That is, referring to FIG.2, if it is assumed that the plurality of PDGNs are provided, the radio network controllers RNC11and RNC12and the mobile switching center MSC can identify each of the PDGNs, and a proper address at which each of the user data terminals UDT can make a call is given to each of the PDGNs. Therefore, when a particular user data terminal UDT requests for a packet data service, a desired particular PDGN may be designated. That is, according to such PDGN designation method, if a PDGN designation identifier field provided in a packet service request originating message from the particular user data terminal has a identifier ID, a radio network controller and a mobile switching center set up a packet call path to be through one of the PDGN designated by the identifier ID. The mobile communication system network is preferably managed such that the user data terminal UDT provides a packet data service limited to a user who provides an exact password and subscriber's name after the PDGN is designated. Even if a call is handed off or roamed due to movement of the user data terminal UDT into corresponding mobile switching center or another mobile switching center under a state a packet data service is underway in the PDGN designation service procedure, the path between the user data terminal UDT and the PDGN is sustained continuously by an interlocked control of the base station BS, the radio network controller RNC and the mobile switching center MSC provided in the mobile communication system network. Eventually, even if the user data terminal UDT is handed off or roamed, the packet data service is provided continuously. Accordingly, when a plurality of PDGNs are managed by ISP connection equipment, many subscribers can be provided with a variety of packet data services.

A signal protocol and a data protocol in accordance with a preferred embodiment of the present invention will be explained with reference toFIGS. 3-5.FIG. 3illustrates a protocol stack architecture of a packet route control signal in accordance with a preferred embodiment of the present invention. Referring toFIG. 3, the AI(Application Interface) layer in the mobile station MT/UDT is provided for use in an Internet/packet network connection service for a user without a proper SMIN in making connection to an AI layer in the PDGN, and also supports a function for selecting an Internet connection or a packet network connection. An APPL layer in the mobile station MT/UDT is an Internet application service or a packet application layer. If a user data terminal UDT with an SMIN makes connection to an Internet IP or a packet host, the APPL layer in the mobile station MT/UDT, determining the connection as a call for an already registered service between transmission layers, connects the call to the PDGN. On the other hand, an APPL layer in the Internet/packet network300inFIG. 3is an element used in calling an SMIN data address assigned to the user data terminal UDT by a user in a wired network. A radio network controller RNC side base station is omitted from elements in a RNC/MSC shown inFIG. 3, because it is understood that a radio packet data control between a mobile terminal MT and a radio access network is made between the mobile terminal MT and the radio network controller RNC. In a signalling system of PKTS(Packet signalling) between a PDGN and a mobile switching center MSC, a UNI(User network interface) suggested in an ITU standard document Q.2931 is employed. However, in the present invention, a function is added, in which a channel transits from an active state to a dormant state for an effective use of sources of a wireless section and the mobile switching center MSC when there is no user data present for a preset period even if a call is not canceled, and a terminating call identifier identifying function using an SMIN number is added for processing terminating calls from originating call side mobile stations in an Internet/packet network. And, a packet control protocol ‘Radio Packet Signalling’ for radio sections of the mobile station MT/UDT and the radio network controller RNC conducts a PSCAF (Packer Service Control Agent Function) of the mobile station (MT/UDT) and a PSCF (Packet Service Control Function) of the radio network controller. And, the radio network controller RNC and the mobile switching center MSC renews a routing table in hand off and roaming for assuring a packet path between the PDGN and the mobile station MT/UDT. If a roamed mobile station MT/UDT intends a connection to the Internet/packet network, the connection is made via a PDGN in a visitor network when the connection is made in a dial up system. On the other hand, when an SMIN of a user data terminal UDT is used, the connection can be made via a PDGN in a home network after passing through the mobile switching center MSC in the visitor network and the mobile switching center MSC in the home network.

FIG. 4illustrates a protocol stack architecture for conducting a data communication based on an Internet/packet network in accordance with a preferred embodiment of the present invention. Once a serial communication path is established according to the signal protocol explained with reference toFIG. 3, an architecture of data communication protocol stack between the mobile station MT/UDT and the Internet server or the packet host is provided as shown in FIG.4. Elements of the mobile switching center MSC is not shown inFIG. 4since the elements only relay in an ATM layer. InFIG. 4, the relay layer inFIG. 4is L2/L3/MAC layer and ATM/AAL layer, and a link layer is connected with a PPP link, and rest of the overlying layers are network layers and a transport layers. The network layer may vary with user service. In an Internet connection using an SMIN and a radio X.25 packet network connection, the network layer in the PDGN is not used except relay function and operative as a peer part with the network in the mobile station MT/UDT.

FIG. 5illustrates a protocol stack for conducting packet data communication between mobile stations in accordance with a preferred embodiment of the present invention.

Referring toFIG. 5, the AAL(ATM Adaption Layer) which transmits a PPP frame may be one which requires no more re-transmission function or an error correction function as overlying layers conduct error correction. However, if a radio link protocol layers L2/L3corresponding to a radio section have a re-transmission function, the AAL preferably has a flow control function for effective buffer management when a frame error is occurred in a radio section. The packet data communication between mobile stations shown inFIG. 5is made possible as peer protocol layers corresponding to each other are put into operation centered on the mobile switching center. Underlying layers of the PPP layer conducts a function connecting end to end, and overlying layers of the PPP layer makes a flow control and an error correction, and supports application services.

As has been explained, the present invention can minimize interlock circuits required in packet data transmission/reception even after PDSNS are removed from a related art mobile communication system network. Even though the PDSNS are eliminated from the mobile communication system network, which requires frequent hand off of mobile stations, a number of signal links required for position registration and confirmation of the mobile station is significantly reduced compared to the related art because the VLR/HLR directly connected to the mobile stations makes position registration and confirmation of the mobile stations.

And, the basic radio data connection services, such as the Internet/packet network connection service, the Internet protocol service for mobile stations, the packet service between mobile stations, provided based on the mobile communication system network of the present invention can provide all data communication application services that are available from a present wired network.

And, a variety of packet data services can be provided if a plurality of PDGNs are provided to the mobile communication system network of the present invention because a mobile station can directly designate a particular PDGN for transmitting/receiving a packet data.

It will be apparent to those skilled in the art that various modifications and variations can be made in the architecture of a mobile communication system network and the method for transmitting a packet data using the same of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.