Abstract: A method for communicating regional broadcast datagrams over a network in which the regional broadcast datagrams are routed using destination identifications wherein a sender terminal sends regional broadcast datagrams to a sub-network grouping server that selects a plurality of sub-network servers according to criteria defined by the sender terminal and chosen as a function of information derived from the sender terminal without the individual destination identifications of the destination terminals being specified by the sender terminal, and wherein the sub-network grouping server provides regional broadcast datagrams to the selected sub-network servers, which subsequently provide the regional broadcast datagrams to a plurality of destination terminals.

Abstract: The invention provides a method and apparatus for building a linked binding cache. The method includes storing mobile router entries in a binding cache. The mobile router entries include a first mobile router entry having a prefix and an indication of the prefix's length along with an associated intermediate address. The method also includes linking a second mobile router entry to the first mobile router entry for delivering at least one data packet via the first mobile router. The method further includes adding a pointer in the binding cache from the entry of the second mobile router to the first mobile router entry when the intermediate address of the second mobile router matches the first mobile router's prefix in order to create a linked binding cache.

Abstract: A method for providing secure communications among a plurality of ad hoc devices includes authenticating one or more first devices within a first network; authenticating one or more second devices within a second network; transmitting a group key to the authenticated first devices and to the authenticated second devices; establishing an ad hoc network by at least one of the authenticated first devices and at least one of the authenticated second devices using the group key; and communicating within the ad hoc network among the at least one of the authenticated first devices and the at least one of the authenticated second devices.

Abstract: A method of supporting mobility in an Internet Protocol (IP)-based data network. The method comprises the steps of generating a first stateful IP autoconfiguration message at a mobile node, whereby the message includes an address capable of use for routing maintenance. The mobile node transmits the generated message to a first access node, which incorporates its address and forwards the message to a dynamic host configuration protocol (DHCP) Server. The DHCP Server and access node analyze the message to determine a route to deliver data to and/or from the mobile node. One or more route update message are triggered from said access node and said DHCP server to a number of network elements between said access node and said DHCP server in the IP based data network to support mobility in an IP domain with minimum bandwidth use and minimum tunneling required.

Abstract: A communication network (100) comprises a roaming network node (109) which may move within the network. The network node (109) comprises a network interface (201) for receiving data from a first node (107) of the network (100). The received data may be multicast data or unicast data. The network node (109) further comprises a multicast processor (205) which determines a multicast characteristic of the first node (107) and an address update processor (207) for selecting between a dynamic address update mode and a non-dynamic address update mode in response to the multicast characteristic. In particular, the network node (109) may operate an address update process, such as a route optimisation or a correspondent registration process, conditionally on whether the foreign network (105) is a multicast node or not. This may improve performance and reduce the signalling overhead associated with route optimisation in a communication network.

Abstract: The invention provides a method and apparatus for building a linked binding cache. The method includes storing mobile router entries in a binding cache. The mobile router entries include a first mobile router entry having a prefix and an indication of the prefix's length along with an associated intermediate address. The method also includes linking a second mobile router entry to the first mobile router entry for delivering at least one data packet via the first mobile router. The method further includes adding a pointer in the binding cache from the entry of the second mobile router to the first mobile router entry when the intermediate address of the second mobile router matches the first mobile router's prefix in order to create a linked binding cache.

Abstract: A method of transmitting a data packet on a communication path from a first communication node (CN1, CN2) to a second communication node (LFN1, LFN2) in a mobile network (115). The method includes receiving a route message (1010, 1020) from the second communication node, wherein the route message includes a list of intermediary addresses ({MR1-COA}, {MR1-COA, MR2-COA}) between the first communication node and the second communication node. A preferred communication path is generated in response to the list of intermediary addresses; and at least one data packet is transmitted from the first communication node to the second communication node via this preferred communication path. In this matter, an optimized data path is determined in order to send at least one data packet to an intended recipient (LFN1, LFN2), for example in a nested mobile network scenario.

Abstract: Known protocols for supporting mobility in relation to Internet Protocol (IP) networks are not able to efficiently support distribution of Binding Update messages to Correspondent Nodes (104) in a set of fixed IP networks (102). Consequently, the present invention makes use of a multi-cast service provided by the IPv6 protocol in order to deliver Binding Update messages to the Correspondent Nodes (104). The use of the multi-cast service to deliver Binding Update messages avoids a proliferation of such messages which would occur under know protocols requiring a mobile node (106,107) to send the Binding Update message to each Correspondent Node (104). Consequently, use of bandwith in the set of fixed IP networks (102) is more efficient.

Abstract: A method and system, for transmitting data to a mobile node (4) over a unidirectional link (12) in a packet data network, for example an IP network, comprises: sending a message from a protocol address, e.g. IP address, of a bidirectional interface at the mobile node (4) to the home agent (6), the message comprising a protocol address of a unidirectional interface at the mobile node (4), wherein the protocol address of the bidirectional interface is different to the protocol address of the unidirectional interface; the home agent (6) transmitting data to the mobile node (4) using the protocol address of the unidirectional interface as the care-of-address; and delivering the transmitted data via the unidirectional link (12) to the unidirectional interface of the mobile node (4). The protocol address of the unidirectional interface may be contained in the message in the form of an extension appended to a registration.

Abstract: A method for providing secure communications among a plurality of ad hoc devices includes authenticating one or more first devices within a first network; authenticating one or more second devices within a second network; transmitting a group key to the authenticated first devices and to the authenticated second devices; establishing an ad hoc network by at least one of the authenticated first devices and at least one of the authenticated second devices using the group key; and communicating within the ad hoc network among the at least one of the authenticated first devices and the at least one of the authenticated second devices.

Abstract: “A method of supporting mobility in an Internet Protocol (IP)-based data network. The method comprises the steps of generating a first stateful IP autoconfiguration message at a mobile node, whereby the message includes an address capable of use for routing maintenance. The mobile node transmits the generated message to a first access node, which incorporates its address and forwards the message to a dynamic host configuration protocol (DHCP) Server. The DHCP Server and access node analyse the message to determine a route to deliver data to and/or from the mobile node. One or more route update message are triggered from said access node and said DHCP server to a number of network elements between said access node and said DHCP server in the IP based data network to support mobility in an IP domain with minimum bandwidth use and minimum tunnelling required.

Abstract: A method of transmitting a data packet on a communication path from a first communication node (CN1, CN2) to a second communication node (LFN1, LFN2) in a mobile network (115). The method includes receiving a route message (1010, 1020) from the second communication node, wherein the route message includes a list of intermediary addresses ({MR1-COA}, {MR1-COA, MR2-COA}) between the first communication node and the second communication node. A preferred communication path is generated in response to the list of intermediary addresses; and at least one data packet is transmitted from the first communication node to the second communication node via this preferred communication path. In this matter, an optimised data path is determined in order to send at least one data packet to an intended receipient (LFN1, LFN2), for example in a nested mobile network scenario.

Abstract: A method of, and apparatus for, communication of datagrams over a network comprising sub-networks (1 to 5) served by respective sub-network servers (7 to 11) from a sender terminal (15), especially a mobile terminal communicating over a wireless link, and a plurality of destination terminals (12 to 19) served by a plurality of said sub-networks (1 to 5), in which the datagrams are routed using destination identifications contained in the datagrams. A sub-network grouping server (20) selects a plurality of the sub-network servers (1,4) and provides communication of datagrams between the sender terminal (15) and destination terminals (12, 13, 16) within the corresponding selected sub-networks (1,4) the selection being made according to criteria, such as geographic position, chosen as a function of information derived from the sender terminal (15) without the individual destination identifications of the destination terminals (12 to 19) being specified by the sender terminal (15).

Abstract: Known protocols for supporting mobility in relation to Internet Protocol (IP) networks are not able to efficiently support distribution of Binding Update messages to Correspondent Nodes (104) in a set of fixed IP networks (102). Consequently, the present invention makes usse of a multi-cast service provided by the IPv6 protocol in order to deliver Binding Update messages to the Correspondent Nodes (104). The use of the multi-cast service to deliver Binding Update messages avoids a proliferation of such messages which would occur under know protocols requiring a mobile node (106,107) to send the Binding Update message to each Correspondent Node (104). Consequently, use of bandwith in the set of fixed IP networks (102) is more efficient.