Abstract: The invention relates to a method for discovering a home agent serving a mobile node upon the mobile node changing its mobility management scheme in a packet-switched network and the implementation of such method in a mobile node or home agent. In order to propose a home agent discover scheme that maintains session continuity in a seamless manner upon a mobile node changing its mobility management scheme, a mobile node comprises information on its location prior to changing the mobility management scheme to one of the first signaling messages transmitted upon changing the mobility management scheme (home agent discovery message). The receiving node uses this information to identify the home agent serving the mobile node or to provide a hint to the home agent where the mobile node is registered in a response message to the mobile node. This approach may also be used for path optimization when a mobile node moves from a trusted to an un-trusted access network.

Abstract: The invention relates to a method for a handover of a mobile node from a non-3GPP to a 3GPP network, and of a mobile node, which is located in a non-3GPP/3GPP network. The handover is improved by discovering an appropriate MME and registering the mobile node at the discovered MME, in advance. This includes to first determine the location of the mobile node in the non-3GPP network, so as to be able to detect an MME in the vicinity of the mobile node's location. The 3GPP contexts are then transmitted to the new MME before the handover is performed. Moreover, the invention teaches to change the Serving-Gateway in the 3GPP network before performing a handover, thereby accelerating the handover. When a handover gets likely, the mobile node's location is determined and a new Serving-Gateway is selected. The data path is changed to go via the new Serving-Gateway.

Abstract: The invention relates to a method for routing packets in a system of packet-switched networks using different internet protocol versions. The system comprises a plurality of home agents, at least one mobile node and at least one correspondent node. A first mobile node is configured with at least one topologically correct internet protocol address of a first internet protocol version and is located in a network supporting at least routing of packets having a header of the first internet protocol version. The method comprises the following steps. Communication is requested with a first correspondent node being configured with at least an internet protocol address of a second internet protocol version and being located in a network supporting at least the routing of packets having a header of the second internet protocol version, by an application on the first mobile node.

Abstract: The invention relates to a method for configuring an IP address of a mobile node attaching to a first access network during an inter-access technology handover from another, second access network. Moreover, the invention relates to a mobile access gateway and a mobile node that participate in this method. First and second access network belong to a network domain offering a network-based mobility function. In order to detect whether a mobile node implements a network-based mobility function a virtual interface discovery is performed by checking whether the mobile node also configures the address according to the home network prefix offered to the mobile node before the handover on its interface to the first access network. In parallel, an address configuration is performed. Based on the detection of whether a virtual interface is implemented at the mobile node, the mobile access gateway may decide whether to use network-based mobility or client-based mobility and change the address configuration.

Abstract: The invention provides a method for trust relationship detection between a core and access network for a user equipment. The gist is that a security tunnel establishment procedure is used so one entity, be it part of the core network or be it the user equipment itself, is provided with information to determine whether the access network is trusted or untrusted. The information may comprise a first IP address/prefix, which is initially assigned to the user equipment, upon attaching to the access network. The necessary information may further comprise a second IP address/prefix, which is an address/prefix that is allocated at a trusted entity of the core network. Depending which entity determines the trust relationship of the access network, it might be necessary to transmit either the first IP address/prefix or the second IP address/prefix or the first and the second IP address/prefix using the security tunnel establishment procedure.

Abstract: The present invention relates to a method for a context transfer in a communication network including a plurality of heterogeneous access networks, wherein a mobile terminal is attached to one of the access networks. Further, the present invention relates to a context transfer manager performing the method. Moreover, the present invention relates to a mobile terminal specially adapted to perform the provided method for a context transfer. To facilitate a context transfer between heterogeneous access networks, the present invention introduces a context transfer manager generating at least one context based on capabilities and parameters associated to the mobile terminal and capabilities and parameters of the neighboring access networks taking into account the respective access technology. Further the context transfer manager is common to the heterogeneous access networks in the communication network and performs the context transfers related to a particular mobile terminal.

Abstract: The present invention relates to a method for a context transfer in a communication network comprising a plurality of heterogeneous access networks, (220, 221, 222) wherein a mobile terminal is attached to one of the access networks. Further, the present invention relates to a context transfer manager performing the method (220, 600). Moreover, the present invention relates to a mobile terminal specially adapted to perform the provided method for a context transfer. To facilitate a context transfer between heterogeneous access networks, the present invention introduces a context transfer manager generating at least one context based on capabilities and parameters associated to the mobile terminal and capabilities and parameters of the neighboring access networks taking into account the respective access technology (FIG. 5). Further the context transfer manager is common to the heterogeneous access networks in the communication network and performs the context transfers related to a particular mobile terminal.

Abstract: The present invention relates to a method and computer-readable medium for loop detection in data packet communication utilizing a tunnel in a network comprising a plurality of nodes. The method comprises the steps of, when a first node transmits a data packet, encoding an identification of the first node in at least two header fields of the data packet to be transmitted, and when the first node receives a data packet, analysing the at least two header fields of the data packet, deciding if a loop exists by determining if the data packet was sent by the first node itself, based on the analysis of the at least two header fields of the data packet.

Abstract: The invention relates to a method for tracking locations of mobile terminals in a communication network. Further, the invention relates to a communication network and apparatuses therein capable of performing individual steps of the method according to different embodiments of the invention. To decrease the signaling load imposed by mobility related signaling the invention suggests to group mobile terminals in so called mobility groups and to reduce the signaling overhead by performing a location update on a per-mobility group basis. In one exemplary embodiment of the invention this is realized by only one of the mobile terminals in a mobility group sending a group location update on behalf of the group to trigger the location update for the mobility group. Alternatively, in another embodiment of the invention, a network operator trusted or controlled entity sends a group location update on behalf of the group to trigger the location update for the mobility group.

Abstract: The invention relates to a method for reducing the header size of data packets exchanged between a Mobile Node and its Home Agent. Different sort of headers are utilized between a Correspondent Node and the MN's HA, and between the MN and its HA. The sort of header used between the MN and its HA allows to reduce the header size of exchanged packets on said data path section, as only one header is necessary, compared to the necessity of two headers of the previous sort, used between the CN and the HA. To achieve this, a modified route optimization procedure is performed between the MN and its HA, wherein the HA participates in the RO on behalf of the CN. Thus, the RO remains transparent for the CN, while the MN thinks normal RO is happening. The invention also relates to several network entities that participate in the method.

Abstract: The invention relates to a method for managing the mobility of a mobile node that moves to a different network, but keeps the same IP address. It is proposed to perform route optimization by a Proxy MIP agent on behalf of the MN, thereby shortening the data-path while allowing network-based mobility. At session setup with a correspondent node, the PCC system in the home network derides whether route optimization is to be performed for the communication session. The PMIPa requests relevant information for the route optimization, including the decision for route optimization and the addresses of MN and CN, from the PCC system in the home network, when the MN attaches to the new network area. Accordingly, route optimization is performed by using the Return Routability Procedure according to MIPv6, thereby applying the MN's IP address as Home Address, and the PMIPa's address as Care-of Address of the MN.

Abstract: The invention relates to a method for mitigating the effects of a DoS attack against a home agent supporting mobility for a plurality of mobile nodes. Furthermore the invention also relates to a home agent, a mobile node and a communication system implementing the method for mitigating the effects of a DoS attack against a home agent supporting mobility for a plurality of mobile nodes. To consider the problem of DoS attacks in the design of a mechanism for improving communication systems enabling mobility of mobile nodes, the invention proposes to configure a plurality of addresses at which the home agent is reachable in a communications network and to assign to each of the mobile nodes at least one of the plurality of home agent addresses. If a denial of service attack is detected by the home agent, the home agent de-configures the home agent address to which data packets of the denial of service attack are destined.

Abstract: The current application concerns a method, mobile node, home agent and system for route optimisation between a mobile node and at least one correspondent node in a packet switched network, wherein a route via a first home agent is redirected via a second home agent. The mobile node sends an extended home test initiation message comprising following information: authentication data, an address of the correspondent node, a first home address and a second home address. The first home agent receives the extended home test initiation message and sends an extended home test message to the second home agent, the extended home test message comprising the information from the extended home test initiation message. The second home agent receives the extended home test message and a communication is routed between the mobile node and the at least one correspondent node via the second home agent.

Abstract: A method and apparatus for improved context transfer in heterogeneous networks is presented. Context information is collected from source entities in a first access network by a context transfer manager and transmitted to a context transfer manager of a second access network which forwards the context information to target entities therein, in one of the context transfer managers at least a part of the context information is translated from a format supported in the first access network to another format supported in the second access network. The method may be carried out proactively preceding a handover or reactively following a handover. In one embodiment, context transfer within one access domain is performed directly between access routers, whereas context transfer between different access domains is performed via the context managers. In another embodiment, beacons from access points are counted in order to determine candidates for a pending handover.

Abstract: The invention relates to a method for packet-switched data transmission between a multi-homed mobile node and a correspondent node in a mobile communication system comprising a plurality of mobile networks. The method comprises the steps of selecting by the mobile node one of its home addresses to be used for communication with the correspondent node. The mobile node registers at least one of a plurality of addresses assigned to a considered network interface as care-of-address at a mobile node's home agent responsible for the selected home address. The correspondent node's home agent and mobile node's home agent receive and store candidate proxy home agent addresses. A correspondent node's home agent sends a request to the correspondent node. The correspondent node registers at least one of a plurality of addresses assigned to a considered network interface as care-of-address at the correspondent node's home agent.

Abstract: The invention relates to a method for routing packets in a system of packet-switched networks comprising a plurality of home agents, at least one mobile node and at least one correspondent node, the mobile node having at least a first home address and communicating with the correspondent node over a first of the plurality of home agents.

Abstract: The invention relates to a method for route optimisation of packet switched data transmissions between a first mobile node and a second mobile node in a mobile communication system comprising a plurality of access networks. The method comprises the step of transmitting return routability protocol packets and data packets. The return routability protocol packets and data packets are analysed, and at least part of an address comprised in headers of the return routability protocol packets and data packets is removed.

Abstract: The invention relates to a method for managing the movement of a mobile node from a first router in a first network to a second router in a second network, wherein the mobile node communicates with a corresponding node. In order to enable seamless communication between the mobile node and the corresponding node, the second router is dynamically configured by the first router to transmit a router advertisement message to the mobile node, the router advertisement message comprising a subnet prefix of an IP address of the mobile node, said subnet prefix belonging to the first network. A layer 3 link change as observed by the mobile node can be postponed and a default router of the mobile node can be changed to the new access router immediately after the layer 2 handover, thus enabling very fast handovers without requiring modifications to the mobile node implementations.

Abstract: The invention relates to the initiation of a service to a mobile terminal capable of communicating via at least a first and second access network. Further, the invention relates to a reduction of power consumption of mobile terminals supporting connectivity to at least two access networks. The invention also relates to mobile communication systems and in particular to mobile communications through heterogeneous access networks. In order to prove improved method for initiating services to mobile terminals and/or to reduce power consumption of mobile terminals, the invention introduces of a sleep state that can be entered by the terminal for an access system if same is not used. Upon requesting a service from/to the mobile terminal, the mobile terminal starts service initiation through a second access system and transits back to active state for the first access system for service provision.

Abstract: The invention relates to a method and system for policy control in a data packet network comprising a user equipment, a gateway and a home policy control node. The method comprises the steps of establishing a session between the user equipment and an application function. Then a session identifier is generated by the user equipment, and the same session identifier is generated by the home policy control node. The user equipment requests bearer establishment from the data packet network and marks bearer establishment packets with said session identifier. The gateway derives a user equipment identifier from the bearer establishment packets and determines policy decisions based on the session identifier and the user equipment identifier. The user equipment marks data packets sent over the established bearer with the session identifier; and the gateway applies policy and charging information for the session to the marked data packets.