International Business Machines Corporation

Arvind Krishna

Hamid Ahmadi

Frederic J Bauchot

Dinesh C Verma

David Frederick Bantz

Kadathur S Natarajan

Michelle M Wetterwald

Colin George Harrison

Mahmoud Naghshineh

Rajendran Rajan

Sanjay Damodar Kamat

Jose Louis Martinez

Edward James Ellesson

Roch A Guerin

Dilip Dinkar Kandlur

Ilan Kessler

Harley K Heinrich

Claus Michael Olsen

Fabien P Lanne

Jeane S Chen

Roger Y Cheung

Murray C Baker

Peter E Reissner

Catherine Soler

Shun Shing Chan

Amotz Bar-Noy

Partha Pratim Bhattacharya

Vinod Gerard John Peris

Richard O La Maire

Catherine Solar

Roselyne Bonnet

Frederic Jacques Bauchot

Michelle Marie Wetterwald

In a wireless communication system ( ), base stations ( ) are connected to a backbone network ( ) such as a wired LAN and act as access points and relays for remote stations ( ). A remote station registers and performs bidirectional communication with one of the base stations designated as its home base station. Base stations have overlapping coverage areas where a remote station is within reception range of several base stations. Such communication system may for instance be a multicell radio LAN using frequency hopping signaling. The method allows to reuse a limited number of network resources such as frequency hopping patterns and assign the same resource to several active base stations. Upon request from a base station, a network controller ( ) connected to the backbone network computes a distance index between the requesting base station and the other active base stations and assigns to the requesting base station the same network resource as the one assigned to another base station with the highest distance index. Information about cells overlaps is centralized in a control database ( ) and used by the network controller to compute distance indexes.

Allocation method and apparatus for reusing network resources in a wireless communication system

A method of controlling packet traffic in an IP network of originating, receiving and intermediate nodes to meet performance objectives established by service level agreements. Traffic statistics and performance data such as delay and loss rates relating to traffic flows are collected at intermediate nodes. A control server processes the collected data to determines data flow rates for different priorities of traffic. A static directory node is used to look up inter-node connections and determine initial traffic classes corresponding to those connections. The rates are combined with the initial traffic classes to define codes for encoding the headers of packets to determine their network priority.

Architecture for supporting service level agreements in an IP network

A method, apparatus and system is provided by which two or more cooperating end-users of the Internet and/or other network can dynamically select and use a single Internet or other network service provider (ISP) from among a multitude of ISPs based on the application requirements. The service provider may be selected in a dynamic fashion. This overcomes the problem wherein traditionally most end-users, whether they are individuals or organizations, are connected to the Internet or other network through a single Internet and/or other network service provider. However, users generally may have more than a single connection to the Internet and/or other network. In such cases the routing of traffic over these multiple connections is handled by IP routers based on the routing information that they exchange with their peers. This information is relatively static in nature and is typically based on the state of links that interconnect the different routers. The invention provides a mechanism for the end-user to take advantage of different rates or services that might be provided by competing Internet and/or other network service providers. Furthermore, there are cases where the choice of which provider to use depends on the application. Thus this invention enables cooperating users (or sites of an organization) to dynamically select different providers on an application by application basis.

Dynamic selection of network providers

A repeater that has a receiver for receiving a signal. A validation module determines whether a signature is present in the received signal. An invalidation module determines whether undesired signal components are present in the received signal. The received signal is transmitted if the signature is present and if the undesired signal components are not present.

Wireless communication system

The present invention is an apparatus for controlling client node access to data items maintained in a storage device. The data items include volatile data items. The apparatus comprises a communication device for communicating with multiple client nodes; and a processor, coupled to the storage device for polling the client nodes to exchange (e.g., retrieve and/or transmit) data related to the volatile data items, via the communication device. The processing system further controls client node access to the data items of the storage device. In this way, the apparatus and method of the present invention remedies the problems associated with directory server overload.

Active polling by network LDAP directory

The present invention is a directory server for monitoring network access requests, which includes a storage device for storing data items and an identifier associated with a monitoring node for at least a selected data item of the data items; a communication device for transmitting signals to the monitoring node; and a processing device, coupled to the storage device and the communication device. The processing device receives a network access request for the selected data item and, responsive to receipt of the request, automatically transmits a signal notifying the monitoring node of the request via the communication device, thereby enabling the monitoring node, e.g., a third party, to enforce traffic class priorities and access characteristics of the network.

Third-party notification by network directory server

In a wireless communication system (106), base stations (118, 120) are connected to a backbone network (116) such as a wired LAN and act as access points and relays for remote stations (128, 132, 136). A remote station registers and performs bidirectional communication with one of the base stations designated as its home base station. Base stations have overlapping coverage areas where a remote station is within reception range of several base stations. Such communication system may for instance be a multicell radio LAN using frequency hopping signaling. The method allows reuse of a limited number of network resources such as frequency hopping patterns and assign the same resource to several active base stations. Upon request from a base station, a network controller (110) connected to the backbone network computes a distance index between the requesting base station and the other active base stations and assigns to the requesting base station the same network resource as the one assigned to another base station with the highest distance index. Information about cells overlaps is centralized in a control database (109) and used by the network controller to compute distance indexes.

Allocation method and apparatus for reusing network resources in a

In a wireless communication system (106), base stations (118, 120) are connected to a backbone network (116) such as a wired LAN and act as access points and relays for remote stations (128, 132, 136). A remote station registers and performs bidirectional communication with one of the base stations designated as its home base station. Base stations have overlapping coverage areas where a remote station is within reception range of several base stations. Such communication system may for instance be a multicell radioLAN using frequency hopping signaling. The method allows reuse of a limited number of network resources such as frequency hopping patterns and assign the same resource to several active base stations. Upon request from a base station, a network controller (110) connected to the backbone network computes a distance index between the requesting base station and the other active base stations and assigns to the requesting base station the same network resource as the one assigned to another base station with the highest distance index. Information about cells overlaps is centralized in a control database (109) and used by the network controller to compute distance indexes.

A method of dynamically allocating bandwidth of channels to cells in a communications cellular network according to user demand. Groups of cells are formed so as to minimize interference within each group, and a particular channel is assigned to each of the groups. The bandwidth of each channel then is dynamically allocated by time division to each of the cells in the assigned group according to user demand in each of the cells thereof.

Multiaccess scheme for mobile integrated local area networks

The present invention uses a novel adaptation of a tree splitting algorithm applied to Radio Frequency (RF) tagging technology to identify many tags in the RF field of a base station. The invention uses the tree splitting algorithm to identify a single tag in a field of a plurality of radio frequency tags. Once the single tag is identified, the identified tag is placed in a Data.sub.-- Exchange state where the base station can access data from the tag memory by using information that identifies the tag.

Multiple item radio frequency tag identification protocol

A communications network having a number of routers, a number of base stations and a number of mobile units maintains communications with the mobile units by assigning a unique address known to the routing entities of the network to each mobile unit. By including the mobile units unique address in topology updates of the network, the location of the mobile unit at any time is made known to all routers of the network. That is, once a mobile unit moves into a domain of a new access point and establishes a new link with the new access point, it uses the topology update mechanism of the network to make its new location known to all routers. Once a router of the network receives topology update information specific to the mobile unit's new location, it updates its routing table such that packets destined to the mobile unit are routed in a path which terminates at the mobile unit and contains its new access point.

Communication system including method and apparatus for maintaining

This invention provides a tag identification system and method for identifying tags in the range of a reader station where the tags are divided into smaller groups, where the tags are identified one group at a time so as to save power by powering off the tags that are not in the group currently being identified. Each tag puts itself in a group by performing calculations from parameters stored in itself and from parameters received from the reader station. In another variation of this invention, only tags which configure themselves to be activated at a final frequency are identified. The set of tags which configure themselves to be activated at the final frequency changes with each identification round until all tags in the range of the reader have been identified.

Power-efficient technique for multiple tag discrimination

A method of routing packets through a fixed source routing communications network from and to mobile units. With this invention an initial access point is determined when a communications session is established to or from a mobile unit through the network. Location information is updated each time the mobile unit moves out of the range of one access point and into the range of another access point of the network. When packets for the session are to be transmitted to the mobile unit from the wired network, the packets are forwarded from the initial access point to a current access point, which by definition is in the range of the mobile unit. When packets for the session are to be transmitted from the mobile unit and to the wired network, the access point intercepts these packets and routes them to their destination and/or initiates route discovery to those destinations. When packets are to be transmitted between mobiles at different access points. The packets are sent between the current access points and not through the home access points.

Mobility enabling access point architecture for wireless attachment to

A Medium Access (MAC) Protocol is utilized for wireless radio access for a plurality of remote stations to a base station on a LAN. There is a time division fixed frame structure in which time is slotted, and time slots are grouped into fixed frames consisting of data and control subframes or periods. The fixed frame structure consists of three periods (A, B, and C) along with their respective headers. The first period, the A period, is used exclusively for data transfer from the base station to the remote stations. The following period, the B period, is used for contention-free data transfer from the remote stations to the base station. The allocation of the data slots in the A and B periods is performed by the base station. The last period of the frame, designated as the C period, is used for the transmission of reservation requests and data from the remote stations to the base station in a random-access contention mode using a slotted Aloha protocol. The duration of the three periods may be varied using a movable boundary technique.

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Briarcliff Manor, NY, United States of America

Arvind Krishna