Abstract: Location update techniques are described. A dormant mobile node updates its location information by sending a first message over a wireless link to an access node. The access node generates a second update message in response to the first message. The second message includes a mobile node identifier and, in some embodiments is directed to the mobile node. The second message is received by a tracking agent, which updates location information corresponding to the mobile node. In the case where second message is an IP message and is routed to the mobile node using Mobile IP, a Mobile IP home agent routes the second message to the mobile node's last point of network attachment where the tracking agent is located and intercepts the message. The tracking agent may send a response message to the access node sending the second message.

Abstract: The invention described herein enables a form of downlink macro-diversity in packet-switched cellular networks. It allows packets to be selectively delivered from a network/internetwork to an end node, e.g., a wireless communication device or terminal, over a set of available link-layer connections to/from the end node, through one or more access nodes, e.g., base stations. Downlink macro-diversity is particularly important when the link-layer connections between the end node and the corresponding access node, e.g., the access links, are subject to independent or partially correlated time variations in signal strength and interference. In accordance with the invention, the end node dynamically selects the downlink to be used out of a set of available access links on a per packet basis subject to prevailing channel conditions, availability of air-link resources and other constraints.

Abstract: Techniques for supporting fault tolerance in communications systems, e.g., cellular communications networks with mobile wireless user devices, are described. In various embodiments end nodes, e.g., mobile devices, store information indicating which other nodes are critical to their operation, e.g., critical to messages and/or signals being properly routed to the individual end node. Different network nodes may be critical to different end nodes. Critical node information stored by an end node may be statically preprogrammed or dynamically generated, or may include a combination of both and static and dynamic information. In some embodiments at least a portion of the information used to determine which nodes are critical to a particular end node is generated dynamically from signaling information, e.g., session control signaling, transmitted and/or received during normal operation of the end node. Faults, failures and/or scheduled outages in various network nodes are detected and/or reported.

Abstract: Traditional circuit-switched cellular systems first authorise the mobile terminal and then secure the wireless access link between the cellular radio access network and the users mobile terminal. The IP protocol is then allowed to run as an application over that access link. Internet access systems traditionally use an unsecured access link and use IP messaging to authorise the Mobile Node (IP host) on the mobile terminal, and the resulting communications. Cellular systems therefore authorise and secure at layer 2 (with respect to IP) whilst Internet systems authorise and secure at layer 3 in general. An Internet compliant cellular system needs to potentially authorise and secure both the MACand IP layers and traditionally this is done with two phases using two independent AAA systems (Authentication, Authorisation and Accounting) with L3 following L2 which results in unnecessary complexity, cost and delay when gaining access to a communications network.

Abstract: A method and apparatus for providing uplink macro-diversity in packet-switched networks that allows packets and/or portions of packets, e.g., frames, to be selectively sent from an end node, e.g., wireless communication device or mobile terminal, over a set of multiple communication connections, e.g., physical-layer or link-layer connections, to one or more access nodes, e.g., base stations. Uplink macro-diversity is achieved in part through intelligent selective forwarding over multiple communication connections, where the forwarding decision is controlled by the end node based on a variety of factors, e.g., physical-layer channel conditions and/or higher layer policy. The forwarding decision is executed on a rapid timescale, e.g., on a per packet basis, to adapt to the dynamically varying conditions of the set of communication connections.

Abstract: Methods and apparatus for improving tunneling techniques and reducing packet loss in mobile communications systems are described. The methods and apparatus are well suited for use with Mobile IP and can facilitate handoff operations. A mobile node establishes multiple tunnels, representing downlinks, from the mobile node perspective. The different downlink tunnels are through different access nodes but terminate at the same home agent. The mobile node maintains, at most, a single uplink tunnel at any given time with the home agent. Tunnels representing uplinks and downlinks are managed independently. Thus, each of the uplink and downlink tunnels can have different lifetimes and can be created/removed independently allowing for flexibility in handoff operations.

Abstract: Group communications methods and apparatus are described. In particular, methods for granting a mobile device access to a communications resource, e.g., the right to transmit data, associated with a group are described. User requests for the communications resource are suppressed by the corresponding mobile device, for periods during which the communications resource has been granted to another mobile device. A mobile device may store a suppressed user request so that a resource request signal may be transmitted after the communications resource has been released by the mobile device that was previously granted the resource. In this manner requests that cannot be granted are not transmitted, increasing communications efficiency as compared to systems where requests are not suppressed at the mobile devices. A priority scheme is used in some embodiments to determine whether or not a request should be suppressed while another device has been granted the communications resource.

Abstract: A mobile communications system that uses IP packets to transmit data between end nodes, such as mobile devices, is described. In order to facilitate session establishment, maintenance, security, and handoff operations, access nodes through which end nodes communicate with one another include a session signaling server module and a mobility agent module. The session signaling server module may be implemented as a SIP server while the mobility agent module may be implemented using Mobil IP signaling. The mobility agent and SIP server within an access node are identified using a single shared identifier, IP address. The same security method and common secret may be used to provide security with regard to both mobile IP messages and SIP messages. Sessions admission decisions and resource allocation for admitted sessions can also take place internally to the access node of this invention without need for signaling to external elements.

Abstract: A beaded plate and method of making same for a heat exchanger includes a plate having a generally planar surface and a plurality of beads extending generally perpendicular to the surface of the plate. The beads are formed in a repeating pattern of non-aligned beads within a plurality of rows of the beads.