Nortel Networks Corporation

Avaya Inc.

Darwin A Engwer

Jonathan M Zweig

Haixiang He

Paul McDaid

According to one embodiment, a method involves receiving an incoming media access control (MAC) frame that includes a header, a frame body and an error detection field. Thereafter, an information element within the frame body is analyzed to determine whether to alter a mobility tunnel between a plurality of networking devices.

Method and apparatus to facilitate the closure of mobility tunnels

According to one embodiment, a method involves determining whether a wireless connection between a first access point and a wireless station has failed. If so, a partial scanning process is conducted only on a subset of communication channels over which data is transmitted by access points neighboring the first access point. The subset of communication channels, inclusive of zero, is determined by analysis of a scanning history database.

Method and apparatus to intelligently perform scanning and assist scanning by profiling scanning history

Fast transitions between access points (APs) in a wireless network may be accomplished when a mobile unit (MU) moves between the APs, by causing a first tunnel to be established between the APs, and causing a second tunnel to be established between the new AP and the MU. A data path having established security and quality of service parameters between the MU and the old AP may be extended through the tunnels, so that communication with the MU is not disrupted while transitioning between APs. Transition processing thus may be decoupled from movement of the MU, so that the MU may continue to receive access to data over the data path. Optionally, once the data path has been so extended, the MU and new AP may engage in authentication and other messaging to formally affect a handover of the data path to the new AP. The APs and MU may be configured to communicate according to the 802.11 protocol.

Method and apparatus for extending a mobile unit data path between access points

A communication protocol that provides load balancing and/or test pattern information between devices is described. A first embodiment of the protocol provides such information via a data frame that is transmitted a definitive time after a special DTIM beacon is transmitted. This protocol provides full compliance with IEEE 802.11. The second embodiment of the protocol modifies the 802.11 beacon data structure with additional information elements.

Seamless roaming options in an IEEE 802.11 compliant network

In a wireless network system having a wired backbone network, one or more access points (APs), and one or more wireless units (WUs), a technique wherein an AP automatically determines a factor indicative of the error(s) occurring in the transmissions of one or more data packets to associated WUs, and automatically adjust the fragmentation threshold in accordance with the transmission error factor. The AP adjusts the fragmentation threshold in a manner that the data throughput is increased. Since the AP automatically and periodically gauges the wireless medium for RF interference that can cause data transmission errors, the fragmentation threshold can be dynamically adjusted to respond to changes in the wireless medium, such as when a microwave oven is turned on, and/or when a Blue Tooth device is traversing the wireless medium, etc. This is much more effective than having a system administrator periodically gauge the wireless medium for the purpose of selecting the appropriate fragmentation threshold.

System and method for dynamic control of data packet fragmentation threshold in a wireless network

A protocol for acknowledging receipt of a multicast or broadcast frame by a wireless unit is described. One embodiment, an Eavesdrop Unicast frame is created for use in a wireless network operated in accordance with IEEE 802.11. The Eavesdrop Unicast frame allows the targeted wireless unit to transmit acknowledgement (ACK) frame but is configured so that other wireless units can scan and obtain information therefrom. Another embodiment is similar in configuration to the Eavesdrop Unicast frame but is fully compliant with IEEE 802.11. Therein, a multicast or broadcast frame is transmitted but one wireless unit is configured to acknowledge receipt of the multicast or broadcast frame. The acknowledgement is accomplished through transmission of a data frame. Yet another embodiment is the transmission of broadcast or multicast frames into corresponding unicast frames.

Reliable broadcast protocol in a wireless local area network

In a wireless network system comprising a wired backbone network, an access point, and one or more associated wireless unit data coupled to the access point by way of a wireless transmission medium, a method of enabling fragmentation of data packet above a fragmentation threshold in one or more wireless units, comprising transmitting a message to the one or more wireless unit having a first control data that causes the one or more wireless units to implement fragmentation threshold in transmitting data packets to the access point. The message is preferably a multicast data packet intended for the one or more associated wireless units. The message may further include a specified fragmentation to be used, and also another control signal for enabling request to send (RTS) and clear to send (CTS) transmission by the one or more wireless units.

Automatic distribution of RTS and frag thresholds

In a wireless network system having a wired backbone network with two or more sub-networks, each having one or more access points for communicating with wireless units via a wireless transmission medium, a system, apparatus and method for a wireless unit to determine whether a candidate access point is on a different sub-network than its current access point. If the wireless unit determines that the candidate access point is on a different sub-network, then the wireless unit releases its current network protocol address which was valid for the current sub-network, and obtains a new network protocol address valid for the new sub-network. This is accomplished by the candidate access point transmitting a multicast packet that includes the network protocol address of the access point and the subnet mask of the sub-network which the access point is on. By receiving this multicast packet, the wireless unit can determine if the candidate access point is on a different sub-network than its current sub-network. Also disclosed is a technique for a wireless unit to determine whether to roam to a candidate access point based on the signal qualities to its current and candidate access points, and whether the candidate access point is on a different sub-network or a designated restricted sub-network.

System and method for a wireless unit acquiring a new internet protocol address when roaming between two subnets

In one embodiment, an authentication method features the generation of an initialization vector at a first electronic device and the determination at the first electronic device whether the initialization vector falls within a first group of initialization vectors. The first group includes a plurality of initialization vectors solely used in connection with an authentication sequence. Information is encrypted using in part the initialization vector for return to a second electronic device if the initialization vector falls within the first group.

Wireless LAN WEP initialization vector partitioning scheme

According to one aspect of the present invention, a method is provided in which an access point and a mobile unit associated with the access point may optionally transmit compressed data to each other if the receiving unit is capable of handling data compression. In one embodiment, the access point communicates to one or more mobile units to inform the one or more mobile units of the access point's compression capabilities. A mobile unit which is associated with the access point, upon being informed that the access point is capable of handling data compression, may optionally compress data prior to transmitting the data to the access point. The access point, upon receiving compressed data from the mobile unit which indicates to the access point that the mobile unit is capable of handling data compression, may optionally compress data prior to transmitting the data to the mobile unit. In one embodiment, the access point considers various factors to decide whether to compress data prior to transmitting the data to the mobile unit. In one embodiment, the mobile unit also considers various factors to decide whether to compress data prior to transmitting the data to the access point.

Growing community of inventors

Pleasanton, CA, United States of America

Darwin A Engwer