A system and method for initiating responses to location-based events includes a rules system for applying one or more rules to state/attribute information corresponding to one or more mobile units, to determine if a location-based event has occurred. If it is determined that a location-based event has occurred, a response is provided to one or more location-based services applications. The response can be used by the location-based services applications to provide location-based services, such as email, instant messaging, paging and the like. A state/attribute database can be used with the system and method to store and update the state/attribute information corresponding to the one or more mobile units.

System and method for initiating responses to location-based events

A shared spanning tree protocol (SSTP) creates a plurality of spanning trees (i.e., loop-free paths) which are shared among one or more virtual local area network (VLAN) designations for data transmission within a computer network. Each shared spanning tree includes and is defined by a primary VLAN and may be associated with one or more secondary VLANs. In order to associate VLAN designation(s) with a single shared spanning tree, network devices exchange novel shared spanning tree protocol data units (SST-PDUs). Each SST-PDU corresponds to a given primary VLAN and preferably includes one or more fields which list the secondary VLAN designations associated with the given primary VLAN. The association of VLAN designations to shared spanning trees, moreover, preferably depends on which path traffic is to follow as well as the anticipated load characteristics of the various VLANs. The association of VLAN designations to shared spanning trees thus provides a degree of load balancing within the network. Data messages tagged with a particular VLAN designation are then distributed by the devices only along the shared spanning tree to which that VLAN has been associated by SSTP.

Shared spanning tree protocol

Automatically configuring network device, network system architecture, and method for configuring one or a plurality of devices on a network. Device and network system architectures and methods for automatically self-initiating and configuring one, a plurality, or hundreds of wired or wireless network devices. Autoconfiguring wireless Local Area Network switch and access point devices connected to the switch. Method for accessing remote server by a device to acquire device configuration information. Method for deploying a network including at least one network device at a facility without the participation of a person having knowledge of networks or network devices at the facility. Computer program and computer program product.

Automated network device configuration and network deployment

The invention relates to a method for performing an intersystem handover of a mobile terminal (5) accessing a communication network via a radio access network (1) of a first type. The communication network comprises at least this radio access network (1) of this first type and a radio access network (2) of a second type. In order to enable an access to the communication network with a radio access technology required or desired by the mobile terminal (5), the intersystem handover is initiated by a transmission of the mobile terminal (5) to the communication network, which transmission comprises information indicating that an intersystem handover from the radio access network (1) of the first type to the radio access network (2) of said second type should be performed. The invention equally relates to a corresponding mobile terminal, to a corresponding communication network, to a corresponding communication system, to a network element of a communication network and to a web switch of a communication system.

Intersystem handover of a mobile terminal

A Multicast Listener Discovery (MLD) protocol query and/or report snooping process is modified to appropriately map secondary PVLAN identifiers to corresponding primary PVLAN identifiers, thereby accommodating other system elements that are otherwise unaware of primary/secondary PVLAN distinctions. Special cases are also accommodated where reverse path forwarding (RPF) checks in support of multicast operation might otherwise fail due to primary/secondary PVLAN distinctions. Additional steps are taken to ensure that PVLAN information properly accounts for changes in configuration and/or location of various network hosts.

Systems and methods for multicast switching in a private VLAN

A method and system are provided for implementing virtual local area networks (VLANs) over ATM using LAN over ATM emulation technology. Server nodes which provide address registration/resolution and which enable multicast and broadcast routing on each VLAN are interconnected into multiple trees. The root server nodes of each tree are interconnected according to a hypercube topology. Data structures for maintaining the locations and routing information of mobile terminals is provided. Methods for constructing and updating the data structures when a mobile terminal moves from location to another also provided. Methods are also provided for routing packets using the data structures to and from mobile terminals.

Method for maintaining virtual local area networks with mobile terminals in an ATM network

An exclusive VCC is maintained between each two communicating work stations (MT pair). The handoff method differs if the MT moves to a coverage area having a base station connected to the same switch as the previous coverage area (intra-switch mobility) or to a coverage area having a base station connected to a different switch than the previous coverage area (inter-switch mobility). In intra-switch mobility, the switch changes the path directly to the new base station and eliminates the path through the original base station. In inter-switch mobility, the switch performs the path set-up. The path may be elongated from the switch connected to the original BS, to the new BS, rather than from the original BS to the new BS. This eliminates the path through the original base station. The exclusive VCC between the MT pair permits path elongation to be minimized.

Seamless handoff for a wireless lan/wired lan internetworking

One of the most powerful virtual LAN (VLAN) features is the capability to group users into broadcast domains, which are independent of their locations on the physical network. This paper deals with VLAN services using ATM LAN emulation technology which operates on a client/server model, and focuses on the issues of supporting transparent VLAN services for mobile terminals. A mobile VLAN architecture is proposed to efficiently maintain multiple VLAN broadcast domains over ATM networks even if the topology is changed dynamically due to mobility. This architecture exploits a hypercube over tree (HOT) hierarchical structure, i.e., trees are connected in a hypercube manner, to interconnect different VLANs servers. To filter excessive server-to-server traffic, an intelligent frame forwarding algorithm is proposed for the servers. The proposed mobile VLAN system brings us a step closer towards facilitating mobility and conforms to existing LAN emulation environment.

Mobility management of interconnected virtual LANs over ATM networks

As broadband multimedia applications to the desk top are becoming popular today, the high-speed bandwidth demand from a single user will occupy large shares of the LAN's channel capacity. Therefore, the evolution of LAN technologies has shifted from shared to dedicated media. More and more LANs are being installed and their interconnection will require parallel switching techniques such as a high-speed switching hub. The ATM small cell-size switching approach is intended to accommodate the mixed media such as voice, data and video. To fulfil the switching cost, bandwidth and latency criteria, a two-stage switching hub for LAN interconnection is designed and presented in this paper. The packet switching technique is used in the first stage switching to efficiently interconnect the local LANs. For the second stage design, the ATM cell switching is adopted to accommodate multimedia traffic and internetworking among LANs and WANs. The switching architecture including both the packet and cell switching units is thoroughly described. The message flow and routing mechanism are presented in the paper. This architecture has been proved to have the advantages of very low latency, flexible scalability and easy routing management with two-way learning. >

Interconnection of large-scale LANs via a two-stage switching hub for multimedia applications

Future broadband networks must support integrated services and offer flexible bandwidth usage. Most existing proposals for wide-area wavelength division multiplexed (WDM) networks employ circuit switching adopting the concept of lightpath, in which each circuit or lightpath occupies an entire wavelength. This, however, is not suited for end-to-end transport of information streams, typically with each stream having its unique traffic characteristics such as the bandwidth needed, different traffic bursty nature, and diverse service requirements. In this paper, we explore the extensions of the functions of what we refer as the optical link control (OLC) layer, native on top of optical layer, to offer finer granularity of wavelength usage and further enable the possibility of bandwidth on-demand (BoD) service directly over WDM networks. The objective is to facilitate the support of integrated services over WDM networks and to mitigate the changes needed in the upper layers as well. The proposed approach attempts to exploit the strengths of both optics and electronics, in which packets are either routed end-to-end over a lightpath transparently, or forwarded from wavelength to wavclength by electronic switching, whenever required. Furthermore, in order to establish an end-to-end BoD connection, the issue of how to select the best wavelength to route the given connection is also investigated. The effectiveness of the proposal is evaluated by simulation.

Yao-Tzung Wang

Papers

Method for maintaining virtual local area networks with mobile terminals in an ATM network

Seamless handoff for a wireless lan/wired lan internetworking

Mobility management of interconnected virtual LANs over ATM networks

Interconnection of large-scale LANs via a two-stage switching hub for multimedia applications

On the support of bandwidth on demand service over wide-area WDM optical networks