|Title of Invention||
AN APPARATUS ENABLING TIGHT INTER-WORKING BETWEEN A WIRELESS LOCAL AREA NETWORK (WLAN) AND A UNIVERSAL MOBILE TELECOMMUNICATIONS SYSTEM (UMTS) AND METHOD THEREOF
|Abstract||In a system having a PLMN (12) and a WLAN IP GW (30), an Iur interface providing handover between a PLMN and the WIP-GW. Mobile internet protocol (Mobile IP) provides session management and data tunneling between the PLMN (home agent) and the WLAN. The WIP-GW functions as the foreign agent toward the PLMN. Services are provided by the PLMN MIP over DIAMETER for registration, authentication and subscriber management, working into the HLR/HSS (14) and the CGF (18) in the PLMN. The use of a single architecture to support the loose inter-working scenarios is such that the architecture minus the Iur interface and MIP becomes a loose inter-working architecture. The UMTS PLMN billing platform is made via the DIAMETER/UMTS inter-working. Authentication is provided by the UMTS PLMN HSS/HLR. The architecture concept can be broadened to cover the inter-working of other access technologies with UMTS.|
|Full Text||FIELD OF INVENTION
The present invention relates to an apparatus and method enabling tight interworking between wireless local area network (WLAN) and universal mobile telecommunication systems(UMTS ).
Different types of wireless communication systems have been developed to provide different types of services. Some examples of the wireless communication systems include wireless local area network (WLAN), and cellular networks such as universal mobile telecommunication systems (UMTS). Each of these systems have been developed and tailored to specific applications.
The adoption of wireless communication networks in enterprise, residential and public domains in some locations is pervasive, and multi-mode user devices have been introduced which are able to communicate with more than one type of network. However, continuous connectivity cannot currently be supported as the users of such devices move from one network to another. Thus, there exists a need for system architecture capable of providing tight inter-working between WLAN and UMTS systems, capable of supporting seamless handover between the two types of networks.
The WLAN and UMTS technologies are effectively combined to inter-work and support a tight inter-working scenario. The UMTS Iur interface is employed for lossless handover, mobile Internal Protocol (IP) is utilized for session management and continuity and DIAMETER protocol signaling is employed for authentication and billing.
BRIEF DESCRIPTION OF THE DRAWING
The Figures 1 and 2 are system architecture diagrams of WLAN and UMTS networks, which embody the principles of the present invention.
DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS
Figure 1 shows a system architecture 10 comprising a public land mobile network (PLMN) network 12 which includes a home location register/home subscriber server (HLR/HSS) 14, an authentication authorization and accounting home facility (AAAH) 16, a charging gateway
function (CGF) 18, a home agent 20 and a general packet radio service support node (GGSN)
A wireless local area network internet protocol gateway (WLAN IP GW), i.e. WIP-GW 30, incorporating a firewall, establishes signaling and data interface with two APs, for example the APs 32 and 34. The user equipment (UE) 36 is preferably a dual mode WLAN/UMTS
Data How in the system shown is as follows:
There is a mobile internet protocol (MIP) interface between WIP- GW 30 and the home agent 20 of PLMN 12. WIP-GW 30 combines the functions of the mobile internet protocol (MIP) foreign agent with some radio network controller (RNC) functions. WIP-GW 30 appears to PLMN 12 as a foreign agent, and to the APs as a WLAN Radio Network Controller (RNC). Incoming data is tunneled between PLMN (the home agent) 12 and the WLAN (WIP-GW) 30 as represented by incoming data line 38. Outgoing data flows directly from WIP- GW 30 to the internet 40 as represented by outgoing internet protocol (IP) data line 42.
The PLMN 12 provides the services of authentication and subscriber management using the HSS.-HLR 14 of PLMN 12. DIAMETER is an IP domain protocol that handles authorization, authentication and accounting functions in an IP network. The use of DIAMETER in this architecture allows IP-based authentication, authorization and accounting (AAA) procedures to run between the WIP-GW and the PLMN. Since the PLMN is essentially a UMTS network. the node providing the authentication and authorization procedures in the PLMN is the HSS'HLR, and the PLMN node providing accounting is the Charging Gateway Function (.CGF). The HLR/HSS and CGF support UMTS procedures and signaling to facilitate these luncuoiis. The AAAH provides the signaling inter-working between IP-based AAA procedures and their corresponding UMTS procedures, allowing the AAA functions to and
from the HSS/HLR and CGF to be made available to the WLAN access system. Similarly, MIP provides procedures for mobility management in an IP network. In a UMTS network, mobility management procedures for packet-switched data services are handled by the GGSN. The Home Agent in this architecture provides the inter-working between the MIP procedures (running between the WIP-GW and Home Agent) and the UMTS Mobile Application Part (MAP) interface towards the GGSN.
MIP-DIAMETER signaling flows from WIP/GW 30 through AAA FOREIGN (AAAF) function 44 and AAA home (AAAH) function 16 to home agent 20. MIP registration messages are encapsulated within the DIAMETER signaling through radio link 48.
AAAH 16 inter-works DIAMETER with mobile application part (MAP) (Gr interface) towards HLR/HSS 14, enabling usage of HSS/HLR for authentication.
AAAH 16 interfaces with the PLMN's charging gateway function (CGF) 18 using GPRS iunncling protocol (GTP) (through the Ga interface) to enable the usage of the PLMN billing
Referring now to figure 2, session continuity between the WLAN and the UMTS PLMN 12 is obtained using MIP (between WIP-GW 30 and Home Agent 20) and GTP (between Home Agent 20 and GGSN 22). The Home Agent 20 provides the inter- working between the two interfaces. Session continuity allows the user's session and IP address to be maintained as the user moves between Access Points, (APs) such as 32 and 34 and between UMTS and WLAN networks. Effectively, the GGSN 22 functions as the anchor point for the data session, as the user moves between these networks. For example, in the architecture 10', if the user moves from the WLAN access network to a UMTS access network (UMTS Access NW), 50, as shown in Figure 2, the user's session remains anchored on the GGSN 22, and is hence maintained during the movement. When in the UMTS access NW 50, the UE 36 communicates with the anchor GGSN 22 via the UMTS Radio Access Network (RAN) and the Serving GPRS Support Node (SGSN) element 52 in the PLMN. Handover between WLAN and UMTS PLMN employs the Iur interface represented at 46. The WIP-GW supports the UMTS lur 46 interface to a Radio Network Controller (RNC) within the UMTS RAN.
1. An apparatus enabling tight inter-working and handover between a wireless
local area network (WLAN) and a universal mobile telecommunications system (UMTS)
(50), the apparatus comprising:
a core network (12) with a means for performing session management and continuity, a means for authentication and a means for billing 14,16,18,20,22,
said UMTS and WLAN each having a communication device for communicating directly with the other via an Iur interface (46) to provide a handover of a user equipment (UE) (36) from one of said UMTS and WLAN to another one of said UMTS and WLAN;
said UMTS and WLAN each implementing the same core network resources for session management and continuity, and authentication and billing; and
said WLAN comprising an internet protocol gateway (IP GW) (30) which comprises a firewall, implementing at least one mobile internet protocol (MIP) foreign agent function and at least one radio network controller (RNC) function.
2. The apparatus as claimed in claim 1, comprising the WLAN and the core network implementing MIP over DIAMETER signaling to provide the WLAN with authentication, authorization and accounting (AAA) services for the UE (36), and session management between the WLAN and the UMTS as the UE (36) moves between said WLAN and said UMTS.
3. The apparatus as claimed in claim 1, wherein said core network (12) is a public land mobile network (PLMN).
4. The apparatus as claimed in claim 3, wherein said WLAN comprises a receiver for receiving incoming data from the PLMN using MIP, and a transmitter for transmitting outgoing data via the internet (40).
5. The apparatus as claimed in claim 4, wherein said PLMN comprises a gateway GPRS support node (GGSN) (22), and a home agent (HA) (20) for tunneling data to an internet protocol gateway (IPGW) (30) provided in said WLAN.
6. The apparatus as claimed in claim 5, wherein said HA (20) communicates with the internet (40) employing IP.
7. The apparatus as claimed in claim 4, wherein said PLMN comprises:
a charging gateway function (CGF) (18) for providing accounting services to the WLAN and the UMTS; and
a home location register/home subscriber server (HLR/HSS) (14) for providing authentication and authorization services to the WLAN and the UMTS.
8. The apparatus as claimed in claim 7, wherein said PLMN comprises authentication, authorization, accounting home (AAAH) (16) which communicates with the CGF (18), the HLR/HSS (14), and an AAA foreign (AAAF) (44) provided in said WLAN, whereby AAA services are provided to the WLAN.
9. The apparatus as claimed in claim 8, wherein the AAAF (44) provides communication of said AAAH (16) with said WLAN IP GW (30).
10. The apparatus as claimed in claim 8, wherein the AAAH (16) cooperates with the HA (20) to provide AAAH services.
11. A method of tight interworking and handover between a wireless local area network (WLAN) and a universal mobile telecommunications system (UMTS) (50) the method comprising:
handover between said UMTS and said WLAN employing an Iur interface (46);
session management, continuity, authentication and billing (14),(16), (18),(20),(22)
between said UMTS and said WLAN employing core network resources, wherein said core
network is a public land mobile network (PLMN), wherein said session management and
continuity achieved by MIP over DIAMETER signaling between the WLAN IP GW (30)
and the core network (12) is provided between the WLAN and the UMTS as a UE (36)
moves therebetween and wherein said authentication is performed by a home location register
HLR/HSS (14) and billing is performed by a charging gateway function means (18) residing
in said PLMN.
|Indian Patent Application Number||4117/DELNP/2004|
|PG Journal Number||06/2011|
|Date of Filing||24-Dec-2004|
|Name of Patentee||INTERDIGITAL TECHNOLOGY CORPORATION, a body corporate incorporated under the laws of the country of US, of 3411 Silverside Road, Concord Plaza, Suite 105, Hagley Building, Wilmington, DE 19810, United States of America|
|Applicant Address||3411 SILVERSIDE ROAD, CONCORD PLAZA, SUITE 105, HAGLEY BUILDING, WILMINGTON, DE 19810, U.S.A.|
|PCT International Classification Number||H04Q 7/24|
|PCT International Application Number||PCT/US2003/020553|
|PCT International Filing date||2003-07-01|