Abstract: The invention describes a method for discovering a server in a neighbour network of an IP node or IP network, said method comprising obtaining inter-network routing information describing a network reachability between networks, determining at least one routing path including the IP node or IP network in the inter-network routing information, selecting a first network on the determined at least one routing path, said first network being located at or close to the IP node or IP network, determining at least one first address, prefix or domain name associated with the selected first network, transmitting at least one server discovery request message for an address, prefix or domain name associated with the selected first network, and receiving at least one reply message containing an address or domain name of a server located in the selected first network, thus discovering a server in the neighborhood of the IP node or IP network.

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 invention relates to a method for reducing the header size of data packets by removing inner headers from the data packets, wherein at least an outer header remains for routing purposes. When removing the inner headers from a data packet, a newly configured address of the receiving and/or the transmitting entity is inserted in the remaining outer header of the data packet. Context information is provided in the receiving entities for reconstructing the removed inner headers, wherein the context information is referred to by the newly configured address that is in the source and/or destination address of the outer header. The reduced data packet is transmitted with only one header, thereby significantly reducing the size of each data packet. The original packet is completely reconstructed at the receiving entity thereby allowing to proceed with the usual processing of each data packet.

Abstract: The invention relates to a method for reducing the header size of data packets exchanged between a Mobile Node (MN) and a gateway that is located between the MN and a Corresponding Node (CN). Different sort of headers are utilized between the MN and the gateway, and between the gateway and the CN. The sort of header, obtained by an optimizing procedure, allows to reduce the header size of exchanged packets on said data path section. To achieve this, a modified route optimization (RO) process is performed between the MN and the gateway, wherein the gateway acts on behalf of the CN. After completing the first RO process, the MN initiates and performs a second RO process with the gateway acting as CN. After completing both route optimization processes, data packet transmission is performed between the CN and the gateway after switching from IPsec tunnel mode to IPsec transport mode.

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 present invention describes a method for signalling to a mobility anchor point a position of a mobile node in a network using a network-based mobility management scheme for managing the mobility of the mobile node, said method comprising receiving, by a network element, from the mobile node, during or after network authentication of the mobile node, a sequence number used by a process implementing a mobile node-based mobility management scheme for managing the mobility of the mobile node, and transmitting, by the network element, to the mobility anchor point a message on a position of the mobile node in the network, wherein said message comprises the received sequence number. A common sequence number variable for BU and PBU messages is used, so that the HA is able to determine a correct transmission order of PBU/BU messages based on the sequence number in the message.

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: A technology is disclosed for providing a handover processing method, and an access point and a mobile terminal used in the method, in which the handover processing method can prevent processing of a HO in a layer 2 and an HO in a layer 3 from occurring at same time simultaneously, and shorten waiting time caused by the HO. The technology includes a step of providing, by the access point, strength information held by the access point itself, the strength information that is information whether to promote a handover processing in the layer 3 or not to promote the handover processing in the layer 3, and a step of receiving, by the mobile node, the provided strength information, deciding whether to perform the handover in the layer 3 based on the received strength information, and performing the handover processing in the layer 3 based on the decision.

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 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.

Abstract: The invention relates to a method for obtaining a home node address in a packet switched network comprising nodes. The method comprises the steps of a first node sending to a first home node of a home network a request containing information about a home address of a mobile node to determine whether a binding with said home address indicating a registration of said mobile node at the first home node exists; the first home node receiving the request, said first home node comprising a stored binding table; determining whether the binding with said home address exists in any home node of the home network; and if the home address of the mobile node is in the binding table of any of the home nodes in the home network, the first node receiving a reply comprising the address of the home node with said binding.

Abstract: The invention relates to a method for node management in a packet-switched network, wherein a first node acts as a proxy for a second node, both nodes having network-layer addresses and link-layer addresses, the network-layer addresses at the network layer and the link-layer addresses at the link layer being used for communication in the packet-switched network. The method comprises the following steps performed by the first node: The first node receives from the second node a request to receive and forward packets addressed to the second node's network-layer address, whereby the same network-layer address is associated with the first node and the second node, and the first node and the second node have distinct link-layer addresses. The first node advertises to nodes attached to the packet-switched network the first node's link-layer address as a destination address for the second node's network-layer address, while the second node does not advertise.

Abstract: The invention relates to a method performed by a home agent serving a mobile node in a home network of the mobile node upon attachment of a mobile node to the home network as well as to the home agent. Further, the invention also relates to a method for enabling simultaneous use of a plurality of interfaces by a mobile node being attached to a home network through one of the plurality of interfaces and to at least one foreign network through at least another interface of the plurality of interfaces. Moreover, the invention provides a mobile node and a proxy acting on behalf of the mobile node. To enable a mobile node to use a home network and at least one further foreign network for communications the invention suggests the registration of the mobile node's home address or of a network node within its home network as a care-of address in the home network.

Abstract: A method and a server acting as a Home Agent are provided for packet switched data transmission between a first mobile node and a correspondent mobile node in a mobile communication system comprising a plurality of mobile networks. Each of the first mobile node and the correspondent mobile node are allocated to respective home networks, and a network server is provided as a home agent to each mobile node, respectively. Then, data packets are routed from the first mobile node to the correspondent mobile node, over a first data tunnel from the first mobile node to any first one of the home agents and over a second data tunnel from said first one of the home agents to the correspondent mobile node without passing the respective other home agent.