(56) References cited:

(1)

Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the

1 4

35 185

B1

&

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EP 1 435 185 B1

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EUROPEAN PATENT SPECIFICATION

(45) Date of publication and mention

of the grant of the patent:

02.12.2009 Bulletin 2009/49

(21) Application number: 02773111.6 (22) Date of filing: 27.09.2002

(51) Int Cl.:

H04W 88/16(2009.01)

(86) International application number:

PCT/SE2002/001775

(87) International publication number:

WO 2003/030570 (10.04.2003 Gazette 2003/15)

(54) Media gateway for interconnecting mobile access networks, and related method

Media-Gateway zum Verbinden von Funkzugangsnetzen und zugehöriges Verfahren Passerelle média pour l’interconnexion des réseaux d’accés mobiles, et procédé associé (84) Designated Contracting States:

AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LI LU MC NL PT SE SK TR

(30) Priority: 01.10.2001 US 969364 (43) Date of publication of application:

07.07.2004 Bulletin 2004/28

(73) Proprietor: TELEFONAKTIEBOLAGET LM

ERICSSON (publ) 164 83 Stockholm (SE)

(72) Inventor: NISKA, Hakan

S-589 35 Linköping (SE)

(74) Representative: Sjöberg, Mats Hakan

Ericsson AB Torshamnsgatan 23 164 80 Stockholm (SE) (56) References cited: EP-A- 1 122 959 WO-A-01/13657 WO-A-01/58086

• EL-HOIYDI A: "Radio Independence in the Network Architecture of the Universal Mobile Telecommunication System" IEEE GLOBECOM 1998, SYDNEY, NSW, AUSTRALIA, vol. 4, 8 - 12 November 1998, pages 1957-1962, XP000894392 ISBN: 0-7803-4985-7

• FYRÖ M ET AL: "Media gateway for mobile networks" ERICSSON REVIEW, no. 4, 2000, pages 216-223, XP000969929 ISSN: 0014-0171 cited in the application

• "Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile

Telecommunications System (UMTS); Network architecture (3GPP TS 23.002 version 4.3.0 Release 4)" ETSI TS 123 002 V4.3.0, June 2001 (2001-06), XP002200605 cited in the application

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5 10 15 20 25 30 35 40 45 50 55 Description

BACKGROUND OF THE PRESENT INVENTION Field of the Invention

[0001] The present invention relates generally to

third-generation mobile networks, and specifically to media gateways within third-generation mobile networks.

Description of Related Art

[0002] Third-generation mobile networks are

de-scribed in the 3G TS 23.002 (3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Network architecture, Release 5) (here-inafter referred to as the Technical Specification). As de-scribed in the Technical Specification, third-generation mobile networks logically divide the infrastructure into a Core Network and an Access Network.

[0003] The basic Core Network is constituted of

circuit-switched nodes, such as Mobile Switching Centers (MSCs), packet-switched nodes, such as General Pack-et Radio Service support nodes (SGSNs) and control nodes, such as Home Location Registers (HLRs). The basic Access Network is constituted of radio control nodes and radio access nodes. As an example, the radio control nodes may be Base Station Controllers (BSCs) for GSM (Global System for Mobile Communications) ra-dio networks and Rara-dio Network Controller (RNCs) for UMTS (Universal Mobile Telecommunications System) radio networks. As a further example, the radio access nodes may be Base Transceiver Stations (BTSs) for GSM radio networks and Node Bs for UMTS radio net-works.

[0004] Third-generation mobile networks also partly

utilize a layered network architecture. Call control and connectivity, which have traditionally been bundled in tel-ecommunications networks, are now separate layers within the Core Network circuit-switched domain. This separation is achieved by dividing the MSCs into media gateways and network servers. The call control layer is resident in the MSC servers, while the connectivity layer is resident in the Media Gateways.

[0005] The Media Gateways serve to bridge the

differ-ent transmission technologies and to add service to end-user connections. The Media Gateways use open inter-faces to connect between the Core Network and an Ac-cess network. The media gateway control interface (H. 248) facilitates this separation of call control and connec-tivity layers. Media Gateways are located within the Core Network as an interface to both the Access Networks and to legacy networks, such as the Public Switched Tele-phone Network (PSTN).

[0006] Recent advances in third generation mobile

networks have made it possible to have each Media Gateway controlled by a single network server or multiple network servers. For example, as described in an article

by Fryo et al. entitled Media gateway for mobile networks, which was published in Ericsson Review No. 4 on Nov. 30, 2000, a single Media Gateway may be controlled by more than one network server within the Core Network by the use of Virtual Media Gateways within the Media Gateway. Each Virtual Media Gateway is controlled by one network server, with resources being shared by all of the Virtual Media Gateways.

[0007] However, by implementing the Media

Gate-ways within the Core Network, call control and connec-tivity are not separated in the Access Network. Therefore, Media Gateways cannot be shared between the Access Network and the Core Network. In addition, for calls be-tween Access Networks served by the same MSC server, physical transmission of payloads (e.g., speech or data) between the Access Networks and the Core Network is still required.

SUMMARY OF THE INVENTION

[0008] The present invention is directed to a Media

Gateway and a method for using H.248 Media Gateways within the whole network (both Core Network and Access Network). The H.248 Access Network Media Gateways enable the separation of the call control and connectivity layers within the Access Network. Each H.248 Media Gateway is capable of serving one or more radio control servers of the Access Network and one or is capable of serving one or more radio control servers of the Access Network and one or more network servers of the Core Network. In addition, pools of devices (e.g., transcoders) can be shared between the radio control servers and network servers.

[0009] Furthermore, the Media Gateways can provide

H.248 Virtual Gateways capable of serving the radio con-trol servers within two or more Access Networks and the network servers within the Core Network. In implemen-tation, one or more H.248 Media Gateways can be placed at strategic locations at the border between two or more Access Networks. Therefore, physical transmission of payloads (e.g., speech or data) between the two different Access Networks is normally not required, logically de-fined only as interface terminations between the Virtual Gateways of the radio control servers and the network servers.

[0010] Furthermore, the Media Gateways within the

Access Network can provide H.248 Virtual Gateways ca-pable of serving the radio control servers within one or more Access Networks and the network servers within the Core Network. In implementation, one or more H.248 Media Gateways can be placed at strategic locations at the border between one or more Access Networks and an external network, such as the PSTN. Calls to PSTN subscribers can then normally be made as local PSTN calls.

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BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The disclosed invention will be described with

reference to the accompanying drawings, which show important sample embodiments of the invention and which are incorporated in the specification hereof by ref-erence, wherein:

FIGURE 1 is a block diagram illustrating a prior art third generation mobile network;

FIGURE 2 is a block diagram illustrating the Access Network architecture in accordance with embodi-ments of the present invention;

FIGURE 3 is a block diagram of an exemplary Media Gateway including one or more Virtual Media Gate-ways for interfacing with Access Network servers and Core Network servers, in accordance with em-bodiments of the present invention;

FIGURE 4 is a block diagram of the components of the Media Gateway and Virtual Media Gateways shown in FIGURE 3; and

FIGURE 5 is an example of a call connection be-tween two Access Networks using the Virtual Media Gateways shown in FIGURES 3 and 4.

DETAILED DESCRIPTION OF THE EXEMPLARY EM-BODIMENTS

[0012] The numerous innovative teachings of the

present application will be described with particular ref-erence to the exemplary embodiments. However, it should be understood that this class of embodiments pro-vides only a few examples of the many advantageous uses of the innovative teachings herein. In general, state-ments made in the specification of the present application do not necessarily delimit any of the various claimed in-ventions. Moreover, some statements may apply to some inventive features but not to others.

[0013] FIGURE 1 shows a conventional

third-genera-tion mobile network 100, in which the call control and connectivity of the Core Network 120 have been sepa-rated into different layers. Within the third-generation mo-bile network 100, the switching fabric is removed from the MSC and placed in a Media Gateway (MGW) 30a. Thus, the MSC is divided internally, creating a MSC serv-er 14 and a MGW 30a. Likewise, the Gateway MSC (GM-SC) is divided internally, creating a GMSC server 15 and a MGW 30b. In addition, for packet data services, the serving General Packet Radio Service (GPRS) support node (SGSN) and the Gateway GPRS Support Node (GGSN) are both divided internally, creating a SGSN server 16, a GGSN server 17 and respective MGWs 30c and 30d for the SGSN server 16 and GGSN server 17.

[0014] The MGWs 30a-30d provide for interworking

between an Access Network, such as the Universal Ter-restrial Radio Access Network (UTRAN) 150a or GSM network 150b, and the Core Network 120. For example, MGWs 30a and 30b provide an interface for handling

circuit-switched traffic between the Access Network 150a or 150b and an external network, such as the PSTN 160a. Likewise, MGWs 30c and 30d provide an interface for handling packet-switched traffic between the Access Network 150a or 150b and an external network, such as the Internet 160b.

[0015] The MGWs 30a-30d each have an H.248

con-trol interface Mc that provides the signaling connection for user traffic control between the servers 14-17 and their respective MGWs 30a-30d. Signaling connections between the servers 14-17 and signaling connections between the servers 14-17 and the Access Networks 150a and 150b are not shown in FIGURE 1, but the MGW=s 30a-30d may route this signaling from the phys-ical interfaces directly to the servers 14-17. The MGWs 30a-30d also includes a number of devices for various services, such as conference calling, announcements and transcoders (e.g., voice coders). In addition, MGWs 30a and 30b are interconnected with other MGWs for circuit-switched payload transmission between MSC/ GMSC servers via the Nb interface.

[0016] As an example, in FIGURE 1, a circuit-switched

call between the UTRAN Access Network 150a and the PSTN 160a is interconnected by MGWs 30a and 30b. Speech originated by a mobile terminal (not shown) in wireless communication with a Node B 25a of the UTRAN Access Network 150a is transmitted to the Radio Network Controller (RNC) 20a of a Radio Network System (RNS) via the lubis interface.

[0017] Thereafter, circuit-switched payloads are

trans-mitted from the RNC 20a over the Iu-CS interface to the MGW 30a. The MGW 30a processes the payloads and provides the interface to the PSTN 160a via MGW 30b. The MSC server 14 and the GMSC server 15 provide the user traffic control for the circuit-switched call by control-ling their respective MGWs 30a and 30b via H.248 control paths Mc. The MGWs 30a and 30b interconnect for rout-ing of the payloads via interface Nb. It should be noted that the Iur interface connects two RNC=s (only one of which is illustrated in FIGURE 1).

[0018] As another example, within FIGURE 1, a

pack-et-switched call between the GSM Access Network 150b and the Internet 160b is interconnected by MGWs 30c and 30d. Packet data originated by a mobile terminal (not shown) in wireless communication with a Base Trans-ceiver Station (BTS) 25b of the GSM Access Network 150b is transmitted to the Base Station Controller (BSC) 20b of a Base Station System (BSS) via the Abis inter-face.

[0019] Thereafter, packet-switched payloads are

transmitted from the BSC 20b over the Gb interface to the MGW 30c. The MGW 30c processes the payloads and provides the interface to the Internet 160b via the Gp interface. The SGSN server 16 and the GGSN server 17 provide the user traffic control for the packet-switched call by controlling their respective MGWs 30c and 30d via H.248 control paths Mc, as described above. The MGWs 30c and 30d interconnect for routing of payloads

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via the Gn interface.

[0020] As can be seen in FIGURE 1, with conventional

third-generation mobile networks, the call control and connectivity layers are not separated within the Access Network 150a and 150b. Therefore, Media Gateways 30a-d cannot be shared between the Access Network 150a and 150b and the Core Network 120. In a new Ac-cess Network architecture, as shown in FIGURE 2 and in accordance with exemplary embodiments of the present invention, a new type of MGW (illustrated as 200a and 200b) can be implemented in each Access Network 150a and 150b, respectively, to serve as the interface directly between the Access Network 150a and 150b and the Core Network (not shown in FIGURE 2).

[0021] Therefore, to separate call control and

connec-tivity, in accordance with embodiments of the present invention, the RNC and BSC are divided internally, cre-ating an RNC server 20a and an MGW 200a and a BSC server 20b and an MGW 200b. The MGWs 200a and 200b provide the Iubis and Abis interfaces to the base stations (Node B 25a and BTS 25b, respectively) of the two Access Networks 150a and 150b. In addition, MGWs 200a and 200b provides the A or Iu-Cs interfaces, re-spectively, to the Core Network (not shown) for circuit-switched traffic, and the Gb or Iu-Ps interfaces, respec-tively, to the Core Network for packet-switched traffic. The radio servers (e.g., RNC server 20a and BSC server 20b) provide the user traffic control for packet-switched and circuit-switched calls by controlling their MGWs 200a and 200b via respective H.248 control paths Mc. Signal-ing connections between radio servers and the base sta-tions, and signaling connections between the radio serv-ers and the Core Network are not shown in FIGURE 2, but the MGWs 200a and 200b may route this signaling from the physical interfaces directly to the servers.

[0022] In addition, in conventional third-generation

mobile networks, as shown in FIGURE 1, calls must al-ways be routed through the Core Network 120 even when the call is between two Access Networks 150a and 150b served by the same MSC server 14. In order to more efficiently manage the load within the Core Network 120, referring now to FIGURE 3, this new type of MGW 200 can also provide the interface between two or more Ac-cess Networks 150a or 150b and between an AcAc-cess Network 150a or 150b and an external network, such as the PSTN or Internet. Therefore, the MGW 200 can be controlled by more than one server via the use of Virtual Media Gateways 210. As shown in FIGURE 3, the RNC server 20a, BSC server 20b, MSC server 14, GMSC serv-er 15 and SGSN sserv-ervserv-er 16 can all intserv-erconnect with the MGW 200 for control of payload traffic (circuit-switched and packet-switched).

[0023] In order for each server (radio and network) to

control payloads routed between an Access Network and an external network, the MGW 200 maintains a separate Virtual MGW 210 for each server. For example, to per-form the protocol conversion between the two Access Networks 150a and 150b, the RNC server 20a and BSC

server 20b each control separate Virtual MGWs 210a and 210b, respectively, within the MGW 200. In addition, the MSC server 14, GMSC server 15 and SGSN server 16 each maintain control of a Virtual MGW 210c, 210d and 210e, respectively, within the MGW 200 for intercon-necting with the legacy networks (e.g., PSTN/PLMN and Internet).

[0024] Separate H.248 interfaces Mc between the

MGW 200 and the servers provide the user traffic control, while separate physical connections (e.g., Gn interface, Gp interface, PSTN interface, Nb interface, Abis inter-face, Iubis interface and Iur interface) to each of the Ac-cess Networks 150 and the legacy networks 160 provide the payload connectivity. Therefore, physical transmis-sion of payloads between the RNC 20a, BSC 20b and the Core Network is no longer required, logically being defined only as interface terminations between the Virtual MGWs (i.e., between Virtual MGW 210a and Virtual MGW 210c, between Virtual MGW 210a and Virtual MGW 210e, between Virtual MGW 210b and Virtual MGW 210c, and between Virtual MGW 210b and 210e). In addition, resources (e.g., transcoders) in the MGW 200 can be shared between the Virtual MGWs 210. Fur-thermore, one or more of such MGWs 200 may be placed at strategic locations at the borders between two or more Access Networks 150a and 150b to provide the connec-tivity between multiple Access Networks 150a and 150b and multiple radio servers 20a and 20b within each of the Access Networks 150a and 150b.

[0025] It should be understood that any type of Access

Network 150 and any number of Access Networks 150 can be served by the MGW 200 shown in FIGURE 3. As an example, in the MGW 200 of FIGURE 3, the GSM Access Network 150b and the UTRAN Access Network 150a are interconnected via the MGW 200. The MGW 200 provides the connectivity between the GSM Access Network 150b and the UTRAN Access Network 150a by converting between protocols used in each of the Access Networks 150a and 150b.

[0026] For example, the GSM Access Network 150b

currently uses compressed speech transmitted over cir-cuits. In the future, the GSM Access Network 150b may transmit speech as IP packets. However, the UTRAN Access Network 150a uses compressed speech trans-mitted over an ATM network. The MGW 200 allows speech to be easily routed between the two Access Net-works 150a and 150b by converting circuit-switched com-pressed speech into ATM-switched comcom-pressed speech and vice-versa.

[0027] A detailed view of the functional architecture of

the MGW 200 and Virtual MGWs 210 is shown in FIGURE 4. All Virtual MGWs 210 are capable of sharing resource components 55 (e.g., transcoders) available from a re-source component database 50. However, rere-source components 55 can also be preconfigured, by identity and type, for any Virtual MGW 210 and stored within the resource component database 50.

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is processed by an H.248 message handler 42 for the appropriate Virtual MGW 210. A connection handler 45 within the Virtual MGW 210 establishes a connection be-tween the Virtual MGW 210 and another Virtual MGW (not shown) and allocates available resource compo-nents 55 according to the resource component database 50.

[0029] Resource components 55 (e.g., transcoders)

are composed of payload framing components 55a and payload stream components 55b. Payload framing com-ponents 55a terminate different protocol layers (e.g., IP, user datagram protocol (UDP) and real-time transport protocol (RTP))and convert the protocols between the different Access Networks or between an Access Net-work and the Core NetNet-work. Payload stream components 55b process the actual speech or data.

[0030] FIGURE 5 illustrates a call between one Access

Network 150b (i.e., GSM) and another Access Network 150a (i.e., UTRAN) using the Virtual MGWs 210 shown in FIGURES 3 and 4. During the establishment phase of a mobile originated call within the GSM Access Network 150b, the calling mobile terminal 10a sends a call set up request and the B-number of a called mobile terminal 10b to the MSC server 14. The call control signaling be-tween the BTS 25b, BSC server 20b and MSC server 14 are well-known in the art, and will not be described in detail herein.

[0031] Upon receipt of the call setup request, the MSC

server 14 reserves a connection point A in the Virtual MGW 210c. The connection point A is associated with the Virtual MGW 210b for the BSC server 20b. The MSC server 14 also instructs the BSC server 20b to establish a connection for the calling mobile terminal 10a to point A in Virtual MGW 210c. In response, the BSC server 20b allocates a speech channel to the calling mobile terminal 10a and orders the Virtual MGW 210b to connect the allocated speech channel to point A in the Virtual MGW 210c.

[0032] To connect the call to the called mobile terminal

10b, the MSC server 14 analyzes the B-number of the called mobile terminal 10b and locates the called mobile terminal 10b (i.e., by interrogating a Home Location Reg-ister). Upon determining that the called mobile terminal 10b is registered in the Visitor Location Register (VLR) of the MSC server 14 and within the UMTS Access Net-work 150a, the MSC server 14 pages the called mobile terminal 10b in the UMTS Access Network 150a. When the called mobile terminal 10b responds to the page, the MSC server 14 selects a connection point B in the Virtual MGW 210c that is associated with the Virtual MGW 210a.

[0033] Thereafter, the MSC server 14 requests the

RNC server 20a to establish a connection for the called mobile terminal 10b to point B in Virtual MGW 210c. In response, the RNC server 20a allocates a speech chan-nel to the called mobile terminal 10b and orders the Vir-tual MGW 210a to connect the allocated speech channel to point B in the Virtual MGW 210c.

[0034] The connection handler within the Virtual MGW

210c of the MSC server 14 establishes a connection be-tween the Virtual MGW 210b of the BSC server 20b and the Virtual MGW 210a of the RNC server 20a. Once the connection is established, payloads can be transmitted between the BTS 25b and the MGW 200 over the Abis interface and between the MGW 200 and the Node B 25a over the Iubis interface to connect the call between the calling mobile terminal 10a and the called mobile ter-minal 10b. The call is controlled via the H.248 interfaces of the RNC server 20a, the BSC server 20b and MSC server 14. Advantageously, resources (e.g., transcod-ers) can be shared between the two Access Networks 150a and 150b.

[0035] As will be recognized by those skilled in the art,

the innovative concepts described in the present appli-cation can be modified and varied over a wide range of applications. Accordingly, the scope of patented subject matter should not be limited to any of the specific exem-plary teachings discussed, but is instead defined by the following claims.

Claims

1. A media gateway (200) for interconnecting two or

more mobile access networks (150a, 150b), com-prising:

a first virtual media gateway (210a) associated with a first one (150a) of said two or more mobile access networks, said first virtual media gate-way (210a) having an H.248 interface to a radio server (20a) within said first mobile access net-work (150a) for handling the user traffic control and a physical connection to at least one base station (25a) within said first access network (150a) for handling the call connectivity to and from said first access network (150a);

a second virtual media gateway (210b) associ-ated with a second one (150b) of said two or more mobile access networks, said second vir-tual media gateway (210b) having an H.248 in-terface to a radio server (20b) within said second mobile access network (150b) for handling the user traffic control and a physical connection to at least one base station (25b) within said sec-ond access network (150b) for handling the call connectivity to and from said second access net-work (150b); and

a third virtual media gateway (210c-e) having an H.248 interface to at least one core network server (14, 15, 16) within a core network (120) for handling the connectivity control between said two or more mobile access networks (150a, 150b) and said core network (120), said first (210a) and second (210b) virtual media gate-ways being interconnected via said third virtual media gateway (210c-e).

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2. The media gateway of Claim 1, wherein each of said

virtual media gateways has a connection handler therein capable of establishing a connection be-tween said first virtual media gateway and said sec-ond virtual media gateway via said third virtual media gateway in order to convert payloads between said virtual media gateways for a call.

3. The media gateway of Claim 2, further comprising:

a database housing resource components, said virtual media gateways being capable of sharing said resource components within said database.

4. The media gateway of Claim 3, wherein said

con-nection handlers are further capable of allocating available ones of said resource components from said database for said call.

re-source components comprise one or more transcod-ers.

re-source components comprise payload framing com-ponents and payload stream comcom-ponents.

7. The media gateway of Claim 3, wherein at least one

of said two or more access networks maintains sep-arate resource components within said database for use by said respective first or second virtual media gateway.

8. The media gateway of Claim 1, wherein one of said

two or more access networks is a Universal Terres-trial Radio Access Network.

9. The media gateway of Claim 1, wherein one of said

two or more access networks is a Global System for Mobile Communications Network.

10. A method for establishing a call connection between

a first mobile access network (150a) and a second mobile access network (150b) interconnected via a media gateway according to claim 1 comprising:

receiving a message at a network server (14, 15, 16) within a core network (120) to setup said call connection;

establishing a logical connection between a first virtual media gateway (210a) associated with said first mobile access network (150a) and a second virtual media gateway (210c-e) control-led by said network server (14, 15, 16); establishing a logical connection between said second virtual media gateway (210c-e) and a third virtual media gateway (210b) associated with said second mobile access network (150b);

allocating resource components from a data-base (50) within said media gateway (200) for said call connection; and

establishing a physical connection between a base station (25a) of said first mobile access network (150a) and said first virtual media gate-way (210a) and between said third virtual media gateway (210b) and a base station (25b) of said second mobile access network (150b) for trans-mission of payloads during said call connection.

11. The method of Claim 10, wherein said step of

estab-lishing a connection between said first and second virtual media gateways comprises:

reserving a connection point in said second tual media gateway associated with said first vir-tual media gateway.

estab-lishing a connection between said second and third virtual media gateways comprises:

reserving a connection point in said second vir-tual media gateway associated with said third virtual media gateway.

allo-cating said resource components further comprises: sharing said resource components between said virtual media gateways.

allo-cating said resource components further comprises: allocating separate ones of said resource com-ponents for said first and third virtual media gate-ways.

Patentansprüche

1. Media-Gateway (200), um zwei oder mehr

Mobilzu-gangsnetze (150a, 150b) zusammenzuschalten, umfassend:

ein erstes virtuelles Media-Gateway (210a), das mit einem ersten (150a) der zwei oder mehr Mo-bilzugangsnetze assoziiert ist, wobei das erste virtuelle Media-Gateway (210a) eine H.248-Schnittstelle zu einem Funkserver (20a) inner-halb des ersten Mobilzugangsnetzes (150a) hat, um die Benutzerverkehrssteuerung zu handha-ben, und eine physikalische Verbindung zu min-destens einer Basisstation (25a) innerhalb des ersten Zugangsnetzes (150a), um die Anrufkon-nektivität zum und vom ersten Zugangsnetz

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5 10 15 20 25 30 35 40 45 50 55 (150a) zu handhaben;

ein zweites virtuelles Media-Gateway (210a), das mit einem zweiten (150b) der zwei oder mehr Mobilzugangsnetze assoziiert ist, wobei das zweite virtuelle Media-Gateway (210b) eine H.248-Schnittstelle zu einem Funkserver (20b) innerhalb des zweiten Mobilzugangsnetzes (150b) hat, um die Benutzerverkehrssteuerung zu handhaben, und eine physikalische Verbdung zu mindestens einer Basisstation (25b) in-nerhalb des zweiten Zugangsnetzes (150b), um die Anrufkonnektivität zum und vom zweiten Zu-gangsnetz (150b) zu handhaben; und

ein drittes virtuelles Media-Gateway (210c-e) mit einer H.248-Schnittstelle zu mindestens ei-nem Kernnetzserver (14, 15, 16) innerhalb eines Kernnetzes (120), um die Konnektivitätssteue-rung zwischen den zwei oder mehr Mobilzu-gangsnetzen (150a, 150b) und dem Kernnetz (120) zu handhaben, wobei das erste (210a) und das zweite (210b) virtuelle Media-Gateway über das dritte virtuelle Media-Gateway (210c-e) zu-sammengeschaltet sind.

2. Media-Gateway nach Anspruch 1, worin jedes der

virtuellen Media-Gateways darin einen Verbin-dungshandler hat, der befähigt ist, eine Verbindung zwischen dem ersten virtuellen Media-Gateway und dem zweiten virtuellen Media-Gateway über das drit-te virtuelle Media-Gadrit-teway herzusdrit-tellen, um Nutz-daten zwischen den virtuellen Media-Gateways für einen Anruf zu konvertieren.

3. Media-Gateway nach Anspruch 2, außerdem

um-fassend:

eine Ressourcenkomponenten enthaltende Da-tenbank, wobei die virtuellen Media-Gateways befähigt sind, die Ressourcenkomponenten in der Datenbank gemeinsam zu nutzen.

4. Media-Gateway nach Anspruch 3, worin die

Verbin-dungshandler außerdem befähigt sind, verfügbar der Ressourcenkomponenten aus der Datenbank für den Anruf zuzuweisen.

Res-sourcenkomponenten einen oder mehrere Transco-der umfassen.

Res-sourcenkomponenten Nutzdaten-Rahmenbildungs-komponenten und NutzdatenstromNutzdaten-Rahmenbildungs-komponenten umfassen.

7. Media-Gateway nach Anspruch 3, worin mindestens

eines der zwei oder mehr Zugangsnetze zur Ver-wendung durch das jeweilige erste oder zweite

vir-tuelle Media-Gateway getrennte Ressourcenkom-ponenten in der Datenbank unterhält.

8. Media-Gateway nach Anspruch 1, worin eines der

zwei oder mehr Zugangsnetze ein UTRAN (Univer-sal Terrestrial Radio Access Network) ist.

9. Media-Gateway nach Anspruch 1, worin eines der

zwei oder mehr Zugangsnetze ein GSM(Global Sy-stem for Mobile Communications)-Netz ist.

10. Verfahren zum Herstellen einer Anrufverbindung

zwischen einem ersten Mobilzugangsnetz (150a) und einem zweiten Mobilzugangsnetz (150b), die über ein Media-Gateway nach Anspruch 1 zusam-mengeschaltet sind, umfassend:

Empfangen einer Nachricht auf einem Netzser-ver (14, 15, 16) in einem Kernnetz (120), um die Anrufverbindung aufzubauen;

Herstellen einer logischen Verbindung zwi-schen einem ersten virtuellen Media-Gateway (210a), das mit dem ersten Mobilzugangsnetz (150a) assoziiert ist, und einem zweiten virtuel-len Media-Gateway (210c-e), das vom Netzser-ver (14, 15, 16) gesteuert wird;

Herstellen einer logischen Verbindung zwi-schen dem zweiten virtuellen Gateway (210c-e) und einem dritten virtuellen Media-Gateway (210b), das mit dem zweiten Mobilzugangsnetz (150b) assoziiert ist;

Zuweisen von Ressourcenkomponenten aus ei-ner Datenbank (50) im Media-Gateway (200) für die Anrufverbindung; und

Herstellen einer physikalischen Verbindung zwischen einer Basisstation (25a) des ersten Mobilzugangsnetzes (150a) und dem ersten vir-tuellen Media-Gateway (210a) und zwischen dem dritten virtuellen Media-Gateway (210b) und einer Basisstation (25b) des zweiten Mobil-zugangsnetzes (150b) zur Übertragung von Nutzdaten während der Anrufverbindung.

11. Verfahren nach Anspruch 10, worin der Schritt des

Herstellens einer Verbindung zwischen dem ersten und dem zweiten virtuellen Media-Gateway umfasst: Reservieren eines Verbindungspunkts im zwei-ten virtuellen Media-Gateway, der mit dem er-sten virtuellen Media-Gateway assoziiert ist.

Herstellens einer Verbindung zwischen dem zweiten und dem dritten virtuellen Media-Gateway umfasst: Reservieren eines Verbindungspunkts im zwei-ten virtuellen Media-Gateway, der mit dem drit-ten virtuellen Media-Gateway assoziiert ist.

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Zuweisens der Ressourcenkomponenten außer-dem umfasst:

gemeinsames Nutzen der Ressourcenkompo-nenten zwischen den virtuellen Media-Gate-ways.

Zuweisens der Ressourcenkomponenten außer-dem umfasst:

Zuweisen von separaten der Ressourcenkom-ponenten für das erste und das dritte virtuelle Media-Gateway.

Revendications

1. Passerelle multimédia (200) destinée à

interconnec-ter deux réseaux d’accès mobile ou plus (150a, 150b), comportant :

une première passerelle multimédia virtuelle (210a) associée à un premier (150a) desdits deux réseaux d’accès mobile ou plus, ladite pre-mière passerelle multimédia virtuelle (210a) présentant une interface H.248 au niveau d’un serveur radio (20a) au sein dudit premier réseau d’accès mobile (150a) en vue de traiter la com-mande de trafic utilisateur, et une connexion physique à au moins une station de base (25a) au sein dudit premier réseau d’accès (150a) per-mettant de traiter la connectivité d’appel vers et depuis ledit premier réseau d’accès (150a) ; une deuxième passerelle multimédia virtuelle (210b) associée à un second (150b) desdits deux réseaux d’accès mobile ou plus, ladite deuxième passerelle multimédia virtuelle (210b) présentant une interface H.248 au niveau d’un serveur radio (20b) au sein dudit second réseau d’accès mobile (150b) en vue de traiter la com-mande de trafic utilisateur, et une connexion physique à au moins une station de base (25b) au sein dudit second réseau d’accès (150b) pour traiter la connectivité d’appel vers et depuis ledit second réseau d’accès (150b) ; et

une troisième passerelle multimédia virtuelle (210c-e) présentant une interface H.248 au ni-veau d’au moins un serveur de réseau fédéra-teur (14, 15, 16) au sein d’un réseau fédérafédéra-teur (120) en vue de traiter la commande de connec-tivité entre lesdits deux réseaux d’accès mobile ou plus (150a, 150b) et ledit réseau fédérateur (120), lesdites première (210a) et deuxième (210b) passerelles multimédia virtuelles étant interconnectées par le biais de ladite troisième passerelle multimédia virtuelle (210c-e).

2. Passerelle multimédia selon la revendication 1, dans

laquelle chacune desdites passerelles multimédia virtuelles présente un gestionnaire de connexion ap-te à établir une connexion entre ladiap-te première serelle multimédia virtuelle et ladite deuxième pas-serelle multimédia virtuelle par le biais de ladite troi-sième passerelle multimédia virtuelle en vue de con-vertir des données utiles entre lesdites passerelles multimédia virtuelles pour un appel.

3. Passerelle multimédia selon la revendication 2,

com-portant en outre :

une base de données hébergeant des compo-santes de ressources, lesdites passerelles mul-timédia virtuelles étant aptes à partager lesdites composantes de ressources au sein de ladite base de données.

laquelle lesdits gestionnaires de connexion sont en outre aptes à affecter des composantes disponibles parmi lesdites composantes de ressources à partir de ladite base de données pour ledit appel.

laquelle lesdites composantes de ressources com-portent un ou plusieurs transcodeurs.

laquelle lesdites composantes de ressources com-portent des composantes d’encadrement de don-nées utiles et des composantes de flux de dondon-nées utiles.

laquelle au moins l’un desdits deux réseaux d’accès ou plus maintient des composantes de ressources distinctes au sein de ladite base de données en vue d’une utilisation par ladite première ou ladite deuxiè-me passerelle multimédia virtuelle respective.

laquelle l’un desdits deux réseaux d’accès ou plus est un réseau d’accès radio terrestre universel.

laquelle l’un desdits deux réseaux d’accès ou plus est un réseau de système mondial de communica-tion avec les mobiles.

10. Procédé destiné à établir une connexion d’appel

en-tre un premier réseau d’accès mobile (150a) et un second réseau d’accès mobile (150b) interconnec-tés par le biais d’une passerelle multimédia selon la revendication 1, comportant les étapes ci-après con-sistant à :

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recevoir un message au niveau d’un serveur de réseau (14, 15, 16) au sein d’un réseau fédéra-teur (120) en vue d’établir ladite connexion d’appel ;

établir une connexion logique entre une premiè-re passepremiè-relle multimédia virtuelle (210a) asso-ciée audit premier réseau d’accès mobile (150a) et une deuxième passerelle multimédia virtuelle (210c-e) commandée par ledit serveur de ré-seau (14, 15, 16) ;

établir une connexion logique entre ladite deuxième passerelle multimédia virtuelle (210c-e) et une troisième passerelle multimédia vir-tuelle (210b) associée audit second réseau d’accès mobile (150b) ;

affecter des composantes de ressources à partir d’une base de données (50) au sein de ladite passerelle multimédia (200) pour ladite con-nexion d’appel ; et

établir une connexion physique entre une sta-tion de base (25a) dudit premier réseau d’accès mobile (150a) et ladite première passerelle mul-timédia virtuelle (210a), et entre ladite troisième passerelle multimédia virtuelle (210b) et une station de base (25b) dudit second réseau d’ac-cès mobile (150b), en vue d’une transmission de données utiles au cours de ladite connexion d’appel.

11. Procédé selon la revendication 10, dans lequel

l’éta-pe consistant à établir une connexion entre lesdites première et deuxième passerelles multimédia vir-tuelles comporte l’étape consistant à :

réserver un point de connexion dans ladite deuxième passerelle multimédia virtuelle asso-ciée à ladite première passerelle multimédia vir-tuelle.

l’éta-pe consistant à établir une connexion entre lesdites deuxième et troisième passerelles multimédia vir-tuelles comporte l’étape consistant à :

réserver un point de connexion dans ladite deuxième passerelle multimédia virtuelle asso-ciée à ladite troisième passerelle multimédia vir-tuelle.

l’éta-pe consistant à affecter lesdites composantes de ressources comporte en outre l’étape consistant à : partager lesdites composantes de ressources entre lesdites passerelles multimédia virtuelles.

l’éta-pe consistant à affecter lesdites composantes de

ressources comporte en outre l’étape consistant à : affecter des composantes de ressources indivi-duelles parmi lesdites composantes de ressour-ces pour lesdites première et troisième passe-relles multimédia virtuelles.

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REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader’s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Non-patent literature cited in the description • Fryo et al. Media gateway for mobile networks.

(56) References cited:

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