KR20070005714A - Providing mobility in a wireless network employing multi-protocol label switching - Google Patents

Abstract

A method is provided ensuring mobility to a mobile host in a wireless network with multi-protocol label switching deployed in the packet switched core network. When the mobile host is handed over between different domains of the radio access network connected to different egress nodes of the core network, a new data tunnel from the ingress node to the new egress node is built up. The mobile host does not change its Internet protocol address during handover. ® KIPO & WIPO 2007

Description

TECHNICAL PROVIDING MOBILITY IN A WIRELESS NETWORK EMPLOYING MULTI-PROTOCOL LABEL SWITCHING

TECHNICAL FIELD The present invention relates to packet data transmission in wireless networks, such as cellular mobile networks and wireless local area networks, and more particularly, to protocols for providing routing of packet data through core networks of wireless networks.

In a wireless network, a mobile data terminal (hereinafter referred to as a "mobile host", MH), such as a mobile phone or a laptop computer, is a packet, for example, with a server computer on the Internet or with another mobile data terminal on another wireless network. It has a switching data connection. Packet data in this relationship may include encoded audio and video signals, video conferencing signals or video streaming, such as hypertext markup language (HTML) documents or voice packet networks (VoIP). In particular, in real-time audio and video data, and also in other forms of data, uncontrolled delays or losses of data packets during transmission may affect the actual use and become useless. In order to solve this problem, a mechanism for securing a specific quality of service (QoS) of packet data transmission is introduced in the related protocol.

A radio network is composed of a so-called core network and a plurality of radio access network (RAN) domains for wirelessly connecting the core network and a mobile host. The core network is externally connected to other networks, such as the world wide internet via a gateway (GW).

A scenario of deploying multiprotocol label switching (MPLS) as a transfer technology between the gateway GW and the radio access network domain is considered. To ensure the required QoS conditions, set up an MPLS-based tunnel between the GW and the RAN domain to deploy the traffic engineering (TE) option of MPLS signaling. A tunnel is a virtual connection between two nodes of a network, where payload data is encapsulated in a lower layer protocol header and transmitted over the network to provide a plain point-to-point connection. Data packets destined for roaming MH are tunneled through the core network in an MPLS-based tunnel or the like.

In this situation of the present invention, there may be a difference between the handover procedure managed in the RAN and the handover procedure managed in the core network which likewise enables rerouting of data traffic (or data tunnel). Since the MH changes the node of attachment (NoA) (i.e., the exit LSR of the data tunnel) during the move, it redirects the packet data in the core network so that the packet data reaches the MH without undue delay or packet loss. How to do it.

For example, mobility management methods of data communication in second generation (global mobile communication system, GSM) and third generation (universal mobile communication system, UMTS) cellular networks have intellectual property. The Internet Engineering Task Force (IETF) has standardized mobility management within an Internet Protocol (IP) based network known as Mobile Internet Protocol (MIP). IP routing uses the packet's IP address as information about the destination point, that is, the IP address clearly determines the point of attachment. MIP extends conventional IP routing, with the possibility of associating a mobile host with two IP addresses reflecting the MH's current point of attachment, namely a static "home" address and a dynamic "care off address (CoA)". do. More detailed information about the function of MIP is disclosed in RFC 3344, C. Perkins et al., August 2002, "IP Mobility Support for IPv4".

The MPLS concept uses two distinct functional aspects, the control side and the forwarding side. In terms of control, standard routing protocols are used to switch information between routers to build and store forwarding tables. Such standard protocols include, for example, the "shortest path first" (OSPF) protocol and the boundary path protocol (BGP). In terms of forwarding, when a data packet arrives, the forwarding component searches the forwarding table to determine routing for each packet. A fixed length short label identifying a forwarding equivalence class (FEC) is attached to each packet. The forwarding aspect of MPLS is based on the label swapping algorithm. A label switch (known as a label switch router (LSR)) as a node of the network performs a routing table lookup to map packets to the FEC, and then label the packets before sending them to the next LSR in the label switching path (LSP). Allocate A detailed description of the MPLS concept is disclosed in RFC 3031, "Multiprotocol Label Switching Architecture", in January 2001 by E. Rosen, Floyd, A. Viswanathan and R. Callon.

The MPLS described above still has a hop-by-hop forwarding paradigm inherited from standard IP routing. Traffic engineering (TE) functionality for MPLS may be deployed to meet QoS requirements while increasing the efficiency and reliability of network operation in the MPLS domain. Conditions for TE-MPLS are disclosed in D. Awduche, J. Malcolm, J. Agogbua, M. O'Dell, J. McManus, September 1999, RFC 2702, "Requirements for Traffic Engineering Over MPLS". . These features are used to optimize the utilization of network resources and to improve traffic-oriented performance characteristics. Since the flow following the LSP is fully identified by the label attached to the inlet node of the path, the LSP established by the TE function is called a TE-LSP or LSP tunnel.

MPLS is a general transmission technology rather than an intellectual property transmission technology, but mobility is not available in the specification. Some recent publications consider the deployment of MPLS in mobile networks. In March 2002, during the Wireless Communications and Networking Conference (WCNC), "A Network Architecture for MPLS-Based Micro-Mobility" by F. Chiussi, D. Khotimsky and S. Krishnan, and June 2002, International During the Conference on Telecommunications, T. Yang, Y. Dong, Y. Zhang, and D. Makrakis's "Practical Approaches for Supporting Micro Mobility with MPLS" literature considers micro-mobility within the network of mobile operators, but 2001 In June, International Conference on Communications (ICC) is underway, Z. Ren, C.-K. Tham, C.-C. Foo, C.-C. The method described in "Integration of Mobile IP and Multi-Protocol Label Switching" by Ko is a macro mobility method. In order to deploy mobility in MPLS, MPLS label switching path (LSP) tunnel switching is required. The mechanism presented in the cited reference is based on the assumption that both mobile IP and MPLS are collocated together so that the MH can obtain a new IP CoA address after handover.

In future wireless networks, interactive services (voice and video conferencing) must be supported. To simplify the maintenance of traffic flow in the downstream and upstream data paths, a two-way MPLS tunnel may be used to connect the gateway and the NoA. The setup of interactive LSPs (in the context of "traditional" MPLS) is based on Internet Draft, Work in Progress, R. Dube, M. Costa's "Bi-directional LSPs for classical MPLS", and (in the context of universal MPLS) 2003 In January, RFC 3473, L. Berger et al., Described in detail in "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions", rather than the process for LSP setup. Rather it differs only in message format. Using the mechanism described above, the interactive LSP setup is indicated by the presence of an "upstream label" in the route message. For the signaling process, there is no difference from the setup of the unidirectional tunnel. See the above cited document for more detailed description.

In the following, the term "initiator" is used to represent an LSR that initiates an LSP setup, and the term "terminator" is used to represent an LSR at the other end of the LSP. This means that in the case of a unidirectional tunnel, the inlet LSR corresponds to the originating device and the outlet LSR corresponds to the terminating device. Since the process of washing the unidirectional and bidirectional MPLS tunnels is not different, in the description of the present invention, a unidirectional tunnel is considered, and the term inlet and outlet LSR can be used for ease of explanation. However, this is not considered to be limiting, and the above procedure can also be applied to a two-way tunnel.

The method of setting up a bidirectional MPLS tunnel provides a means for both symmetric and asymmetric tunnels. Symmetric two-way tunnels with voice services or video conferencing may be desirable. In contrast, when a two-way tunnel is used to support video streaming, an asymmetric tunnel where the bandwidth for the upstream path is lower than the bandwidth for the downstream path can be optimized for traffic conditions. The method according to the invention does not affect the process of setting up a symmetric / asymmetric tunnel.

The MPLS architecture does not assume a single label distribution protocol, and therefore, in terms of control, different signaling protocols such as label distribution protocol (LDP) and resource reservation protocol (RSVP) may be used. Initially, RSVP was designed to meet the concept of integrated services (IntServ), which implements QoS in standard IP-based networks. Using extensions in RSVP with some additional objects, RSVP can be used as a signaling protocol using TE in MPLS. Extended RSVP is known as RSVP-TE, which is described in December 2001 by RFC 3209, D. Awduche, L. Berger, D. Gan, T. Li, V. Srinivasan, G. Swallow. Extensions to RSVP for LSP Tunnels ". In particular, the extended RSVP protocol supports the demonstration of explicit routing LSPs, with or without resource reservations. It also supports natural rerouting, pre-emption, and loop detection of LSP tunnels.

In the following description of the present invention, RSVP-TE is considered as an exemplary signaling protocol. However, it should be appreciated that the present invention can also be applied to other specific protocols for providing data tunnels in packet switching networks. Two mechanisms are currently available for RSVP-TE, which allows to implement changes to existing LSP tunnels. These mechanisms include the MPLS-based recovery mechanism and the LSP change mechanism proposed in RFC3209.

The MPLS-based recovery mechanism verifies the rerouting of the LSP when a link or node failure occurs. A framework for this mechanism is disclosed in RFC 3469, and the proposed solution consists of two different techniques for local recovery: one-to-one backup (forming a detour LSP at each potential point of local recovery) and User function backups (forming bypass tunnels to detect potential failure points) can be found in the proposed "Fast Reroute Extensions to RSVP-TE for LSP Tunnels".

Common to both of the above mechanisms is that the SESSION entity of RSVP-TE's "path" message (see RFC 3209) remains the same, which means that the entry and exit nodes of the LSP tunnel as well as the LSP ID are not changed. it means. Thus, with the mobile MH and the location of the exit LSR changes, none of the mechanisms described above can be used for the signaling of the present invention.

Accordingly, what is needed is a method that provides for mobility for mobile hosts in a wireless network with multi-protocol label switching deployed in the core network while enabling continuous routing of packet data.

In CA2292252 of "SYSTEM AND METHOD FOR MOBILE SPECIFIC LABEL EDGE ROUTER OPERATION WITHIN A CORE AND EDGE NETWORK", the packet switching communication network uses a mobile specific label edge router (MLER) configured with mobility management. The MLER supports handover of calls from the label switching path to the first MLER associated with the current serving wireless base station to another label switching path for the second MLER associated with the target base station. In the method described above, a path is available between the label edge router (LER) and the BS. In handover, the label edge router changes the MPLS header of the data packet destined for the old base station with the MPLS label targeting the new base station. CA2292252 proposes partitioning of LSPs within the MPLS domain, where the intermediate LER changes the header of the packet. This requires the expansion of the function of the intermediate LER. Therefore, there is a need for a simplified method with minimal additional requirements for intermediate nodes in the core network.

WO0045560A2 of "PUBLIC MOBILE DATA COMMUNICATIONS NETWORK" is an example of a public mobile access network using a home / external agent model, where a home agent and an external agent transmit data packets through a public mobile access network via a data tunnel. Mobile IP packets are sent using MPLS LSPs. The home agent is located at a point near the Internet backbone, with each base station executing an external agent function. The data tunnel is established between the home agent and one of the external agents. WO0045560A2 assumes mobile IP operating over an MPLS LSP. This requires expanding functionality from the mobile host. Thus, there is a need for a method that significantly reduces the mobility management of mobile hosts.

In the method disclosed in WO2003030467A2 of "MPLS DATA TRANSMISSION IN PACKET-ORIENTED MOBILE RADIO NETWORKS", a unique MPLS label is assigned to each terminal. This MPLS label enables explicit addressing of the data packet to the terminal. Routers tunnel information packets using MPLS or other tunneling protocols. Provided is a method for a terminal that notifies an MPLS router about a unique MPLS label. The MPLS router then tunnels the data packet to the terminal using label stacking. WO2003030467A2 discloses that each terminal has a unique MPLS label that enables tunneling from the entry point to the mobile host. This requires the adoption of signaling in radio access networks. There is a need for a way to not include a mobile host in MPSL functionality.

The introduction of MPLS into mobile networks includes the advantages of packet switching networks that can provide QoS (particularly related to real-time services) and TE. Since the MH roams between BSs (and consequently between ARs), the inlet LSR at the end of the MPLS will change during the handover. In such a scenario, an appropriate method of providing mobility to the MH is required. Currently known methods of using mobility in MPLS are based on mobile IP and require the MH to receive a new IP address when registering for a new AR.

In particular, if the entry node changes during handover, there is a need for an improved simple method of providing mobility for mobile hosts in a wireless network.

Summary of the Invention

Accordingly, it is an object of the present invention to provide mobility in an improved simple way for mobile hosts in a wireless network with multiprotocol label switching deployed in the core network. Another object of the present invention is to provide a function capable of maintaining a predefined quality of service of a packet switching connection while the mobile host is moving within the service area of a wireless network.

This object is achieved by the methods and systems of the independent claims. Possible embodiments of the invention are defined in the dependent claims.

In one embodiment of the present invention, the method comprises: (a) setting up a first multi-protocol label switching tunnel from an ingress node to a first egress node serving a first radio access network domain; Moving from the service area of the first radio access network domain to the service area of the second radio access network domain, (b) a second multi-protocol label switching tunnel from the inlet node to the second outlet serving the second radio access network domain. Setting up, wherein the mobile host with the IP address in step (b) is the same as the IP address assigned to the mobile host in step (a).

The method of setting up a new tunnel at the second (new) exit node instead of rerouting the existing tunnel provides the advantage of compatibility with existing resource reservation protocols because the tunnel endpoint address is part of the tunnel identifier. do. Mobility coordination is simplified because it can be managed at the inlet node without requiring additional functionality at the intermediate node, thereby reducing the requirement for the functionality of the MH.

In another embodiment, the second MPLS tunnel may have a quality of service parameter, such as a quality of service parameter of the first MPLS tunnel. Thus, when the MH moves inside the service area of the wireless network, the quality of service may not change.

In another embodiment, the only difference between the identifiers of the first and second MPLS tunnels is the tunnel endpoint address. This provides the advantage of simple signaling and reduces the traffic required for signaling in the core network.

In another embodiment, the second MPLS tunnel is established before the first MPLS tunnel is teared down. This embodiment provides the advantage of improved reliability that avoids the risk of loss of data packets.

In yet another embodiment, the setup of the second MPLS tunnel may be initiated from the first exit node.

This embodiment provides a simple signaling advantage since the first (old) exit node has all the information needed to request the second (new) exit node to set up a new tunnel.

In yet another embodiment, the method further comprises the steps of: (c) notifying the first exit node of the handover, (d) by the first exit node, (d1) sending a connection confirmation signal to the second exit node, (d2) sending a message with information about the second exit node to the entry node, and (e) upon receipt of the message specified in (d2) by the entry node, a second to the second exit node; Initiating the setup of the multi-protocol label switching tunnel, and (f) receiving, by the second exit node, the connection confirmation signal defined in (d1) from the inlet node with respect to the setup of the second multi-protocol label switching tunnel. After signaling, completing a handover procedure in the network, (g) switching traffic from the first tunnel to the second tunnel by the ingress node upon receiving a tunnel setup confirmation signal, (h ) Release of the first tunnel by the entry node It may contain.

This embodiment provides the advantages of fast and reliable signaling while requiring only one component within the protocol that must be newly introduced and not part of the current standard.

In yet another embodiment, step (c) comprises (c1) notifying, by the mobile host, the second exit node of the mobile host's IP address and the IP address of the first exit node; and (c2) the second exit node; Requesting, by the node, authentication from the first exit node.

In another embodiment, the message in step (d2) is a dedicated message in the resource reservation protocol. This embodiment provides the advantage of compatibility with existing protocols.

In another embodiment, the message in step (d2) includes a dedicated entity in the resource reservation protocol. This embodiment provides the advantage of compatibility with existing protocols, since the same components common to both tunnels are not repeated in step d2, while at the same time minimizing signaling traffic.

In another embodiment, the first exit node notifies the handover as well as the identifier of the second exit node by the mobile host in step (c). In addition, this embodiment may be implemented in the absence of a direct connection between the first and second exit nodes through the core network, for example in the absence of a direct connection with a loosely coupled radio access network domain.

In another embodiment, the entry node checks for other available tunnels to the mobile host via the first exit node in step (c) and initiates setup of the tunnel to the second exit node for each such tunnel. do. This embodiment can significantly reduce the signaling between the first exit node and the ingress node since the first exit node has to send the message in step (d2) only once for all existing tunnels to the same MH. That provides the benefits.

In another embodiment, the setup of the second multiprotocol label switching tunnel is initiated from the second exit node.

In another embodiment, the method includes (i) informing the first exit node of the IP address of the second exit node by the mobile host, and (k) from the first exit node to the second exit node. Transmitting the context information, (l) setting up a second multi-protocol label switching tunnel by sending a request from the second exit node to the entry node, and (m) by the entry node, defined in step (c) After receiving the received request, initiating the setup of the second multi-protocol label switching to the second exit node, and (n) by the second exit node, regarding the setup of the second multi-protocol label switching tunnel to the entry node. After receiving the signaling from the network, completing the handover process in the network, and (o) switching traffic from the old tunnel to the second tunnel when the tunnel setup confirmation signal is received by the entry node. And (p) releasing the old tunnel by the inlet node.

This embodiment provides the advantage of fast and reliable signaling while requiring only one component in the protocol that must be introduced new and not part of the current standard.

In another embodiment, the request in step (l) may be a dedicated entity in the resource reservation protocol. This embodiment minimizes signaling traffic while providing the advantage of compatibility with existing protocols since the same components common in both tunnels are not repeated in step (l).

In another embodiment, the entry node checks for another available tunnel to the mobile host via the first exit node in step (m), initiating setup of a second tunnel for each such tunnel. Since the first exit node has to send the message in step (l) only once for all existing tunnels to the same MH, it is possible to reduce the signaling between the first exit node and the entrance node as much as possible. To provide.

In yet another embodiment, the wireless network is a cellular network. This embodiment provides the advantage of compatibility with existing cellular networks.

In yet another embodiment, the wireless network is a wireless local area network. This embodiment provides compatibility with existing local area networks.

In an embodiment, the telecommunications system comprises a multiprotocol label switching network having a plurality of label switching routers, wherein one of the nodes is configured as an entry node to form a node connected to an external packet switching network, and an internet protocol address; A mobile host configured to receive packet data, and each radio access network domain comprises a plurality of radio access network domains configured to wirelessly connect one of the nodes and the mobile host, the network from the inlet node, the mobile; And to set up a first multi-protocol label switching tunnel to a first egress node that connects a first radio access network domain belonging to a first service area in which the host is located, wherein a mobile host determines its location in the first radio access network.Changing from the first service area of the main to the second service area of the second radio access network domain, establishes a second multi-protocol label switching tunnel from the ingress node to a second exit node connecting the second radio access network domain. Setup, the mobile host does not change the internet protocol address.

The telecommunication system according to this embodiment provides an advantage that can be obtained by updating the existing system due to compatibility with the existing resource reservation protocol. There is no requirement for additional functionality at the intermediate node, and the requirement for functionality of the MH is reduced.

In another embodiment, a first exit of a multiprotocol label switching network configured to receive packet data from an ingress node of the network via a multiprotocol label switching tunnel and transmit the packet data to a mobile host through a first radio access network domain. The apparatus forming the node, after receiving information about the handover of the mobile host from the first radio access network domain to a second radio access network domain, connects the second egress node to the second radio access network domain. Sending an acknowledgment message to the ingress node and a message with information about the second outlet node.

The apparatus according to this embodiment may preferably act as an exit node of the telecommunication system according to the above-described embodiment.

In yet another embodiment, an inlet node from an external packet switching network to a multi-protocol label switching network is formed, and packet data is received from the external network to convert the packet data into a multi-protocol label switching tunnel. An apparatus configured to transmit to a mobile host via a first exit node and a first radio access network domain may send a message with information about a second exit node to which the location of the mobile host is handed over and attaches to a second radio access network domain. After receiving from the first exit node, initiating setup of a second multi-protocol label switching tunnel to the second exit node, and after receiving a tunnel setup confirmation signal from the second exit node; From the first tunnel to the second tunnel And switching the pick and releasing the first tunnel.

The device according to this embodiment may preferably act as an entrance node (gateway) to a telecommunication system according to another embodiment of the present invention.

1 illustrates an exemplary structure of a wireless network;

2 illustrates handover of a mobile host between two exit nodes of a core network;

3 shows a protocol stack of the entity shown in FIG. 2;

4 illustrates the signaling flow between entities involved in the handover process when the setup of a new MPLS tunnel is initiated from a first (old) exit node;

5 is a diagram illustrating another example of the signaling flow shown in FIG. 4;

6 shows the signaling flow between entities involved in the handover process when the setup of a new MPLS tunnel is initiated by a second (new) exit node, FIG.

7 is a diagram illustrating a process of coordinating a multi-tunnel to a mobile host;

8 illustrates the form of an MPLS tunnel identifier;

9 is a diagram showing the form of a SESSION_ATTRIBUTE entity of RSVP-TE;

10 is a diagram illustrating a configuration of a PATH message of RSVP-TE;

11 illustrates the possibility of a new message of RSVP-TE requesting setup of a new MPLS tunnel from an ingress node;

12 illustrates the possibility of a new entity of RSVP-TE requesting the setup of a new MPLS tunnel from an ingress node.

The accompanying drawings form a part of and include a part of the specification in order to explain the theory of the present invention. The drawings are not to be understood as limiting the invention to only one example that illustrates and describes examples of how the invention may be formed and used. Additional features and advantages will become apparent from the following more detailed description, as described in the accompanying drawings.

Embodiments of the present invention will be described with reference to the drawings in which like elements and structures are designated by like reference numerals.

1 shows an example of a network configuration 100 for deploying TE MPLS in a wireless network including a core network 113 and a radio access network (RAN). In the RAN, several access technologies may be supported, such as wireless local area network (WLAN), third generation RAN and fourth generation RAN or DECT. Each different radio access technology is organized locally in a radio access domain managed by an access router (AR). The AR is connected to the core network 113 via a core edge router (CER). 3G and 4G access domains 104 and 105 are connected to CER 28.

The MPLS tunnel 4 or 5 is set up between the entry LSR 1 and the exit node LSR 2 or 3, eg, NoA (AR or base station, BS) in the mobile network (e.g., gateway, GW). . Packets destined for the MH 6 are encapsulated in the inlet LSR 1 (i.e., the MPLS label is added to the IP header), transmitted through the previous setup MPLS tunnel 4, and decapsulating the outlet LSR 2. The data is further transmitted in accordance with the original IP address 7. It is contemplated that the GW 1 also performs the function of an external agent (FA) described in MIP specification RFC 3344, and assigns a CoA address 7 to a valid external MH 6 within the overall mobile network 100. . The exit LSR 2 is executed at the NoA where the MH 6 requires authentication in handover. In the system architecture shown in FIG. 1, the NoA is an AR, but in other scenarios it may be a BS. MH 6 does not support MPLS. Further, assuming that packet transmission within the radio access domain 104 is performed at layer 2, since one radio access domain forms any kind of local area network (LAN), from FIG. You can see that it ends in AR. However, the MPLS tunnel may end at another node, eg BS, that performs the function according to the present invention.

The MH 6 is a mobile computing device such as a notebook or 3G user device (UE). The MH 6 is connected to the BS 113 over a wireless link, ending wireless communication and enabling wired packet switching oriented connection with other entities in the mobile network. The BS may be the last entity, which terminates the MPLS tunnel 4.

When the MH 6 moves in the direction of the arrow 115 so that the MH 6 enters the service area of the BS 114 and is out of the service area of the BS 113, the BS 113 and BS ( In addition to 114, handover between the first RAN domain 104 and the second RAN domain 105 is required. In order to continue sending data packets to the MH 6, the network builds a new LSP 5 at the second exit node 3. The location database of the MH is not placed in the network, but is concentrated in the inlet LSR where the database is formed and stored. Using a database, the ingress LSR can map each input data packet to an MPLS tunnel based on the IP address. Thus, as long as the MH roams within the same wireless network, it is not necessary to change the MH's IP address.

2, a detailed illustration of the wireless network 100 is shown. First, the mobile host 6 is wirelessly connected to the old exit LSR 2 and receives data packets from the gateway or inlet LSR 1 via the first tunnel or LSP 4. In the example of FIG. 2, the LSP passes through one intermediate LSR 8, which may be a core edge router. In another example, LSP 4 may pass through this plurality of intermediate LSRs. After the handover, the MH 6 is in wireless connection with the new exit LSR 3. The new LSP 5 is built from the inlet LSR 1 to the new outlet LSR 2, and data traffic is switched from the LSP 4 to the LSP 5. After that, the old LSP 4 can be released.

3 shows the protocol stacking on the data side of an MPLS network. 301 is the protocol stack of the gateway 1, 302 belongs to the intermediate LSR 8, 303 belongs to each exit LSR 2 or 3, and 304 belongs to the mobile host 6. Each pair of neighboring nodes in the network maintains bidirectional data connections 305 and 306 in terms of the MPLS protocol. The MPLS tunnel 307 is a virtual point-to-point connection from the entry node 1 to the exit node 2 or 3. This is done by hopping the encapsulated data packet over the MPLS data connections 305 and 306. The egress node 2 or 3 sends the received data packet to the MH 6 via connection 308 at layer 2 of the radio access network protocol, for example.

4 illustrates an example method of setting up a new MPLS tunnel from an inlet node to a new outlet node that the mobile host has handed over and initiated by the old outlet node to which the mobile host has been connected so far. 4 shows that the old exit node correctly matches (1) the authentication and connection session parameters of the MH, (2) the entry node of the MPLS tunnel, (3) the tunnel traffic parameters, and (4) the IP address of the new exit node. It has the advantage of knowing. The steps for setting up a new MPLS tunnel are described in detail below.

When the MH detects a new NoA (which becomes a new exit LSR) in step 401, in step 402 the MH requires authentication and notifies about its IP address and the IP address of its current (old) NoA (old exit LSR). do.

If the MH is authenticated using network resources, the new exit LSR is not known and, at step 403, requests authentication from the old exit LSR still serving the MH. Extensible Authentication Protocol (EAP) represents one possibility for communication to proceed between the MH and the new exit LSR and between the new exit LSR and the old exit LSR.

Upon receiving a request from the new exit LSR, the old exit LSR checks the database at step 404. If the MH is currently being serviced by the old exit LSR (ie, an authenticated and operating tunnel is opened from the gateway), the LSR initiates two operations to enable handover. (i) send a connection confirmation signal to the new exit LSR, and (ii) update the new exit LSR to send a message 406 to the entrance LSR. The latter message includes, for example, the IP address of the MH and the new exit LSR. Since the ingress LSR needs to update the database, it needs information about the associated MH, where the incoming IP packet is classified in the MPLS tunnel according to the IP address of the MH.

Upon receiving an update message from the exit LSR, the entrance LSR initiates the setup of a new TE tunnel to the new exit LSR with the same parameters as the old tunnel in step 407. During the setup process, the inlet LSR still transmits the MH's traffic for the old tunnel.

After receiving the connection confirmation signal and tunnel setup signaling, the new exit LSR completes the handover procedure in the RAN to achieve full handover of the MH.

Finally, upon receiving the tunnel setup confirmation signal 408 by the ingress LSR, in step 409 the traffic is changed from the old tunnel to the new tunnel to release the old tunnel in step 410.

Referring to FIG. 5, as another method of the signaling flow shown in 403 of FIG. 4, the old exit LSR may obtain an identifier (eg, an IP address) of the new exit LSR by the MH shown in step 501. This acquisition may be possible if direct communication between the new exit LSR and the old exit LSR is not possible (eg due to loose coupling between the RAN domains) due to the network configuration. In such a scenario, the MH may notify the old exit LSR about the new NoA (new exit LSR), and as a result, the old exit LSR initiates signaling to the inlet LSR.

The advantage of the method shown in Figs. 4 and 5 is that the old exit LSR can signal the identifier (e.g. IP address) of the new exit LSR directly to the entrance LSR, saving the delay of additional signaling that might otherwise be needed. This can speed up the process.

6 illustrates another embodiment of the present invention in which signaling is initiated by a new exit LSR. This option may be possible if the new exit LSR and the old exit LSR communicate with each other to switch traffic context parameters, such as, for example, existing tunnel traffic parameters. In third generation partnership projectors, the traffic context parameter is called the PDP context. In step 601, the new exit LSR periodically sends a broadcast message. In the case of version 6 of the Internet protocol, for example, a router announcement message is sent every three seconds. After receiving the message, the MH notifies the old exit node of the IP address of the new exit node in step 602. As a result, the old exit LSR communicates the traffic context to the new exit LSR in step 603. In this way, the new exit LSR informs about the identifier (IP address) of the inlet LSR, which is part of the MPLS tunnel parameter included in the context. Here, the new exit LSR may contact the inlet LSR at step 604 and requires the setup of a new MPLS tunnel to the new exit LSR. Signaling is completed by steps 605 through 608 in the same manner as described above before associating with FIG. 4.

In the above process, setup of one MPLS tunnel per user is considered. However, the method can also be applied when one user is connected to a gateway through multiple tunnels. This is the case when a tunnel is set up per application because different applications may have different QoS requirements. When a user of an MH connected to a gateway through multiple tunnels moves to a new NoA, one of the methods described above may be applied to each tunnel individually. However, this process may be optimized with the example process shown in FIG. 7 in other embodiments. When the entrance LSR receives a notification message from the old exit LSR and establishes one scene tunnel to the new exit LSR, the entrance LSR begins process 700. First, in step 701, a new list with an existing MPLS tunnel defined as a first entry in the request message is formed. The entrance LSR then checks the database for other available tunnels for the same user in step 702. Other tunnels found as a result of this search are added to the list. At step 703, the entry node sets up a new MPLS tunnel to the scene exit LSR for the first entry in the list, which is deleted at step 704. In step 705, it is checked whether the list is empty. If empty, the process ends at step 706. Otherwise, go to Step 703 to handle the next entry in the list.

The method described above can be applied to both unidirectional and bidirectional MPLS tunnels. The procedure described above may be the same in both cases, since the setup of the two-way tunnel is actually initiated by the inlet LSR (initiator), and the difference from the one-way tunnel is only in the form of an RSVP-TE message.

Referring to FIG. 8, an example data structure 800 is shown that clearly identifies an MPLS tunnel. It includes two entities from the RSVP-TE protocol: SESSION entity 801 and SENDER_TEMPLATE or FILTER_SPEC entity 802. SESSION entity 801 includes the IP address 803, tunnel identifier 805, and extended tunnel identifier 806 of the tunnel endpoint, that is, the exit node of the network. Field 804 has no meaning in the present invention and is filled with zeros. The SENDER_TEMPLATE or FILTER_SPEC entity contains the IP address and tunnel identifier 809 of the tunnel sender, i.e., the entry node of the network. In addition, field 808 is filled with zeros. The structure of FIG. 8 is an example of a data structure that identifies a tunnel. Other structures may be envisioned that serve the same purpose.

9 illustrates a data structure of the SESSION_ATTRIBUTE entity 900 in RSVP-TE as an example of a data structure for conveying QoS information. Fields 901 through 903 are optional and will not be described in detail. Field 904 defines the priority of the tunnel relative to other traffic with respect to extracting the resource, and may expect a value between 0 and 7. Field 905 defines the priority of the tunnel for storing the resource. Flag 906 is a control switch regarding the routing of the tunnel and is not considered in detail in this paragraph. Field 908 contains the session name padded with zeros, and field 907 contains the length of this name. In other protocols, structures other than those shown in FIG. 9 may serve the same purpose of defining the quality of service of the tunnel.

FIG. 10 shows the structure of the RSVP-TE PATH message 1000 sent by the ingress node to establish a new tunnel, as in steps 407 and 605 of FIGS. 4 and 6, respectively. This includes the SESSION entity 801 described in conjunction with FIG. 8, the SESSION_ATTRIBUTE entity 900 from FIG. 9, and the SENDER_TEMPLATE entity from FIG. 8. The EXPLICIT_ROUTE object contains child objects that define network nodes that must be traversed by the route in the tunnel. The other fields of the PATH message 1000 are not described in more detail.

According to one embodiment of the invention, the only difference in identifier between the old tunnel and the new tunnel is the tunnel endpoint address 803. This means that the same SENDER_TEMPLATE and FILTER_SPEC entity 802 along with the modified SESSION 801 and EXPLICIT_ROUTE 1005 entities are sent in route message 1000 along with the route of the new MPLS tunnel. Since the mobile operator is fully aware of the topology of the network, the path of the scene tunnel can preferably be determined at high speed.

In the implementation of the proposed method, a new entity or message is required in the protocol for a request to set up a new MPLS tunnel for an existing tunnel, for example used in step 406 or 604.

11 shows an example of a possible structure of such a message 1100. Because the identifier of the newly requested tunnel is different from the identifier of the existing old tunnel, only the endpoint address differs from the old 1 SESSION entity with the IP address of the old exit node next to the header 1101, and the new exit node. It can only contain scene SESSION objects with IP addresses. Thus, the message 1100 may preferably be kept short.

A case where a new entity 1200 (usually contained within a route message) in the protocol is used for a setup request for a new tunnel is illustrated in FIG. 12. In this proposal, entity 1200 can be obtained by extension of SESSION entity 801, appended with the IP address 1201 of the new exit node.

As a possible advantage, since the connection with the corresponding part is maintained during the handover, the process shown in Figs. 4 to 6 enables seamless mobility to the MH. These handovers may be between base stations in the range of both the same or different access technologies. The above handover procedure in the core network enables tunnel mobility and can satisfy this mobility at high speed without packet loss. This mobility is achieved by the theory of "make-before-brake" because the new MPLS tunnel is set up before the traffic is switched on the new tunnel and finally the old tunnel is released.

In order to avoid negotiation of session QoS parameters between the MH and the network managing the entity for the traffic context, the proposed method uses the same tunnel parameters as in the old tunnel. Another advantage of the proposed method is that, apart from the inlet LSR and the outlet LSR, the implementation of the signaling protocol does not require a change of arrangement. In other words, no change in intermediate LSR is required. In addition, by the proposed method, the available RSVP-TE signaling can be widely used, and the necessary change can be minimized.

Another advantage of the method described above is that there is no need to implement micro mobility mobile IP at the network entity except for the gateway and the MH. Since most of the routers currently on the market are capable of MPLS, the above-described embodiment can be implemented as a handover process only from the network side. The effort of signaling and processing is reduced compared to micro mobility MIP extension. In addition, MH is mitigated from mobility management tasks delivered by network equipment. This reduces processing power, resulting in lower power consumption, which allows for smaller battery and MH.

While the present invention has been described in connection with embodiments configured in accordance with the present specification, those skilled in the art will recognize that various changes, modifications, and improvements of the present invention are also within the scope of the appended claims without departing from the spirit and scope of the invention. It can be seen that in terms of. In addition, parts considered to be familiar to those skilled in the art are not described in order not to unnecessarily obscure the present invention described herein. Accordingly, the invention is not limited by the specific embodiments, but only by the appended claims.

Claims (21)

A method for providing mobility of a mobile host to a wireless network using multiprotocol label switching as a transfer technology between a gateway and a plurality of radio access network domains, the method comprising: a) setting up a first multi-protocol label switching tunnel from the inlet node to the first outlet node serving the first radio access network domain; If the mobile host moves from the service area of the first radio access network domain to the service area of the second radio access network domain, b) setting up a second multi-protocol label switching tunnel from the inlet node to a second outlet node serving the second radio access network domain; Including but not limited to: The mobile host has an IP address in step b) that is the same as the IP address assigned to the mobile host in step a). How to provide mobility for a mobile host. The method of claim 1, And wherein the second multiprotocol label switching tunnel has the same quality of service parameter as the quality of service parameter of the first multiprotocol label switching tunnel. The method of claim 2, And the difference between the identifiers of the first and second multi-protocol label switching tunnels is merely a tunnel endpoint address. The method of claim 3, wherein And the second multi-protocol label switching tunnel is set up before the second multi-protocol label switching tunnel is torn down. The method of claim 4, wherein And said setup of said second multi-protocol label switching tunnel is initiated from said first exit node. The method of claim 5, c) notifying the first exit node about the handover; d) sending, by the first exit node, a message for the connection to the second exit node; d2) a message with information about the second exit node to the entry node; e) initiating, by the ingress node, the setup of a second multi-protocol label switching tunnel to the second outlet node upon receiving the message defined in d2); f) completing a handover procedure in the network after receiving, by the second exit node, an acknowledgment signal defined in d1) and signaling from the inlet node regarding the setup of the second multi-protocol label switching tunnel. To do that, g) switching traffic from the first tunnel to the second tunnel when a tunnel setup confirmation signal is received by the ingress node; h) releasing said first tunnel by an ingress node; How to provide mobility for a mobile host. The method of claim 6, Step c) is c1) notifying, by the mobile host, the second exit node about the IP address of the mobile host and the IP address of the first exit node; c2) requesting, by the second exit node, authentication from the first exit node; How to provide mobility for a mobile host. The method of claim 7, wherein And said message in step d2) is a dedicated message in a resource reservation protocol. The method of claim 7, wherein And wherein said message in step d2) comprises a dedicated entity in a resource reservation protocol. The method of claim 6, In step c), the first exit node is informed by the mobile host about the handover and about the identifier of the second exit node. The method of claim 6, The ingress node checks for another available tunnel to the mobile host via the first outlet node in step e) and initiates setup of the tunnel to the second outlet node for each such tunnel. How to provide mobility for the host. The method of claim 4, wherein And said setup of said second multi-protocol label switching tunnel is initiated from said second exit node. The method of claim 12, (i) notifying, by the mobile host, the old exit node of the IP address of the second exit node; (k) transmitting context information from the old exit node to the second exit node; (l) setting up the second multi-protocol label switching tunnel by sending a request from the second exit node to the inlet node; (m) initiating, by the entry node, the setup of the second multi-protocol label switching to the second exit node after receiving the request defined in step (c); (n) completing, by the second exit node, a handover procedure in the network after receiving signaling from the ingress node regarding the setup of the second multi-protocol label switching tunnel from the ingress node; (o) switching traffic from the old tunnel to the second tunnel when a tunnel setup confirmation signal is received by the ingress node; (p) releasing the old tunnel by the inlet node; How to provide mobility for a mobile host. The method of claim 13, And said request in step l) is a dedicated message in a resource reservation protocol. The method of claim 13, And said request in step l) is a dedicated entity in a resource reservation protocol. The method of claim 13, And the ingress node checks for another available tunnel to the mobile host via the old exit node in step m) to initiate setup of a second tunnel for each such tunnel. The method according to any one of claims 1 to 16, And wherein said wireless network is a cellular network. The method according to claim 1 to 16, And wherein said wireless network is a wireless local area network. A multiprotocol label switching network having a plurality of label switching routers, wherein one of the nodes is configured as an inlet node to form a node connected to an external packet switching network; A mobile host having an Internet protocol address and configured to receive packet data; A plurality of radio access network domains, each radio access network domain configured to wirelessly connect one of the nodes and the mobile host Including, The network is configured to set up a first multi-protocol label switching tunnel from the inlet node to a first egress node connecting a first radio access network domain belonging to a first service area in which the mobile host is located; If the mobile host changes its location from the first service area of the first radio access network domain to a second service area of a second radio access network domain, Set up a second multi-protocol label switching tunnel from the inlet node to a second outlet node connecting the second radio access network domain, The mobile host does not change the internet protocol address Telecommunication systems. A first outlet of the multi-protocol label switching network configured to receive packet data from an inlet node of a multi-protocol label switching network through a multi-protocol label switching tunnel and transmit the packet data to a mobile host through a first radio access network domain. In the apparatus for forming a node, Upon receipt of information about the handover of the mobile host from the first radio access network domain to a second radio access network domain, sending a confirmation message to a second exit node connecting the second radio access network domain; Wow, Further configured to execute the step of sending a message with information about the second exit node to the entrance node. First outlet node forming apparatus. An inlet node is formed from an external packet switching network to a multiprotocol label switching network, and receives packet data from the external network to convert the packet data into a multiprotocol label switching tunnel, a first exit node of the multiprotocol label switching network, and a first A device configured to transmit to a mobile host through a radio access network domain, the device comprising: A second multi-protocol label switching tunnel to the second exit node upon receipt of a message from the first exit node with information about a second exit node connecting the second radio access network domain to which the mobile host is handed over; Initiating the setup of; Upon receiving a tunnel setup confirmation signal from the second exit node, switching traffic from the first tunnel to the second tunnel; Further configured to execute the step of releasing the first tunnel. Inlet node forming device.

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