Abstract: The performance and ease of management of wireless communications environments is improved by a mechanism that enables access points (APs) to perform automatic channel selection. A wireless network can therefore include multiple APs, each of which will automatically choose a channel such that channel usage is optimized. Furthermore, APs can perform automatic power adjustment so that multiple APs can operate on the same channel while minimizing interference with each other. Wireless stations are load balanced across APs so that user bandwidth is optimized. A movement detection scheme provides seamless roaming of stations between APs.

Abstract: The performance and ease of management of wireless communications environments is improved by a mechanism that enables access points (APs) to perform automatic channel selection. A wireless network can therefore include multiple APs, each of which will automatically choose a channel such that channel usage is optimized. Furthermore, APs can perform automatic power adjustment so that multiple APs can operate on the same channel while minimizing interference with each other. Wireless stations are load balanced across APs so that user bandwidth is optimized. A movement detection scheme provides seamless roaming of stations between APs.

Abstract: The performance and ease of management of wireless communications environments is improved by a mechanism that enables access points (APs) to perform automatic channel selection. A wireless network can therefore include multiple APs, each of which will automatically choose a channel such that channel usage is optimized. Furthermore, APs can perform automatic power adjustment so that multiple APs can operate on the same channel while minimizing interference with each other. Wireless stations are load balanced across APs so that user bandwidth is optimized. A movement detection scheme provides seamless roaming of stations between APs.

Abstract: The performance and ease of management of wireless communications environments is improved by a mechanism that enables access points (APs) to perform automatic channel selection. A wireless network can therefore include multiple APs, each of which will automatically choose a channel such that channel usage is optimized. Furthermore, APs can perform automatic power adjustment so that multiple APs can operate on the same channel while minimizing interference with each other. Wireless stations are load balanced across APs so that user bandwidth is optimized. A movement detection scheme provides seamless roaming of stations between APs.

Abstract: The performance and ease of management of wireless communications environments is improved by a mechanism that enables access points (APs) to perform automatic channel selection. A wireless network can therefore include multiple APs, each of which will automatically choose a channel such that channel usage is optimized. Furthermore, APs can perform automatic power adjustment so that multiple APs can operate on the same channel while minimizing interference with each other. Wireless stations are load balanced across APs so that user bandwidth is optimized. A movement detection scheme provides seamless roaming of stations between APs.

Abstract: The performance and ease of management of wireless communications environments is improved by a mechanism that enables access points (APs) to perform automatic channel selection. A wireless network can therefore include multiple APs, each of which will automatically choose a channel such that channel usage is optimized. Furthermore, APs can perform automatic power adjustment so that multiple APs can operate on the same channel while minimizing interference with each other. Wireless stations are load balanced across APs so that user bandwidth is optimized. A movement detection scheme provides seamless roaming of stations between APs.

Abstract: A catalytic converter substrate comprising: a plurality of cell groups, each cell group comprising a plurality of air-flow cells extending axially through the substrate, each cell group comprising a first set of walls defining a radially outer periphery thereof and a second set of walls suspended by the first set of walls partitioning the individual air-flow cells from each other, wherein the first set of walls has a first effective thermal mass and the second set of walls has a second effective thermal mass, wherein the first effective thermal mass is greater than the second effective thermal mass.

Abstract: A plurality of physical addresses are derived from address information stored in an address memory of a bridge or other multi-port communication device, wherein the stored address information does not directly specify all the addresses. In a first embodiment, the stored addressing information specifies a single address value from a first block of preferably consecutive address values. A processor uses the first address value to derive a second address value from a second, different block of preferably consecutive address values, and then assigns both as, e.g., port addresses. In a second embodiment of the invention, the address memory stores address information which specifies a range of preferably consecutive address values, for instance, the first and last address values of the range. A processor fetches these address values from the address memory, identifies all address values within the range, and assigns them as, e.g., port addresses.

Abstract: A technique for controlling access to a bridge connected to at least two networks, such that buffer memory requirements are minimized. For at least one target network of the two networks, two dynamic lists are maintained, to keep track of data packets received from the target network and not yet forwarded, and to keep track of data packets stored for forwarding to the target network, but not yet forwarded. The target network uses a half-duplex medium and a CSMA/CD (Carrier Sense Multiple Access with Collision Detection) protocol. The invention operates by adjusting network protocol parameters used in the target network, to either guarantee or deny priority to the target network in the event of a collision, based on the continually observed status of the two lists. One of the adjustments modifies a backoff value that determines the amount of time that the bridge device will wait, in the event of a collision, before attempting to retransmit a data packet.

Abstract: A method and related apparatus for establishing a point-to-point cross-link between two bridges in a bridged communication network. The bridged communication network is first configured in a loop-free arrangement by a spanning tree algorithm that selects which links of every bridge to activate in order to form the spanning tree active configuration. Then at least one cross-link not defined by the spanning tree configuration is established for routing of messages as an alternative to a spanning tree path. A protocol in each bridge ensures that no loops are formed and that only messages to preselected locations are passed over the cross-link. An optional optimization procedure measures message propagation times in both directions between the two bridges and over both the cross-link path and the spanning tree path, to determine whether to modify usage of the cross-link.

Abstract: A distributed digital data processing system includes a plurality of nodes which communicate over a network. A node maintains one or more objects, each of which may be a file, that is, an addressable unit in the system, such as a program, database, text file, or the like, or a directory which may contain one or more files or other directories. One node maintains a naming service which associates each object in the system with one or more protocol towers. Each protocol tower identifies the object name and a series of entries each identifying a name for each of the protocol layers, along with the communications parameters and address information, to be used in communicating with the object. When a node requires access to an object maintained by another node, it first retrieves from the naming service the protocol towers for the object. The node also maintains a tower identifying the names of each of the protocols over which it can communicate.

Abstract: The present invention provides a method and apparatus for establishing point-to-point full duplex communication between two stations served by a local area network (LAN) or connected by a communication link. One station initially transmits a request message through the link. The request message indicates that a first station is available for full duplex communication and also serves as a test to determine whether any non-full duplex devices are present along the point-to-point link between the first station and a second station. A second station receives the request message and responds by transmitting a reply message which indicates its availability for full duplex communication. Subsequently, full duplex communication may commence. The two stations periodically exchange additional messages to continuously verify that full duplex communication is operating properly.

Abstract: A method and apparatus for detecting invalid network topologies in a local area network (LAN). The stations comprising the LAN include single attachment stations (SAS), dual attachment stations (DAS), wire concentrators (WC), and DAS/WC combination stations. Adjacent stations exchange connection type information identifying a type of physical connection of the station sending the connection information. A station receiving the connection information determines whether the connection is valid for its physical connection type using a connection matrix. Invalid connections can result in a network topology where stations are physically connected, but are not logically connected, because the stations do not all form a primary ring. Invalid connections may be rejected and bypassed in each station. Alternately, a station detecting an invalid connection may reconfigure itself using an internal data switch. The actions of each station, taken together, achieve a globally designated primary ring.

Abstract: A method and apparatus for controlling the topology of a local area network (LAN) configured as a ring of trees. The stations comprising the LAN are limited to single access stations (SAS), dual access stations (DAS), wire concentrators (WC), and DAS/WC combination stations. The topology control requires the exchange of connection type information only between immediately adjacent stations. The resulting simplicity in the information exchange requirments allows validation and rejection of invalid connections or reconfiguration of the network topology to be implemented as low as the Physical layer of the ISO model.