International Business Machines Corporation

Columbia University

Mahmoud Naghshineh

Claus Michael Olsen

Parviz Kermani

Babak Rezvani

Chatschik Bisdikian

Anthony S Acampora

Arvind Krishna

Peter Dirk Hortensius

Danny N McKay

Hamid Ahmadi

Murray C Baker

Roger Y Cheung

Pravin Bhagwat

Ibrahim Korpeoglu

Frederic J Bauchot

Daby Mousse Sow

Partha P Bhattacharya

Roch A Guerin

Fritz R Gfeller

Stefan Berger

Gerald Arnold Marin

Nathan J Lee

Levent Gun

Fabien P Lanne

William Francis Jerome

Ilan Kessler

Frank P Novak

Jeane S Chen

Peter E Reissner

Michelle M Wetterwald

Patrick K Kam

Frank J Janniello

Catherine Soler

Veronique Perret

Partha Pratim Bhattacharya

Eduardo M Kolbe

Roberto M Kobo

Catherine Solar

Timucin Ozugur

Roselyne Bonnet

Puneet Pandoh

Khosrow Sohraby

Jeffrey, H Derby

Frederic Jacques Bauchot

Michelle Marie Wetterwald

Provides methods and apparatus for accessing and controlling services, such as home automation services, visually employing established wireless, cellular telecommunication technologies for voice communications. In example embodiments, users of personal portable devices connect to services over dial-up, wireless, cellular, circuit-switched voice telephone networks, receive and display listings of available services and use these listings to access and manipulate the services.

Pervasive, personal data interactivity over voice-grade circuit-switched cellular networks

The present invention provides methods and apparatus to protect user privacy while accessing information in public places, using both public and personal devices. This is achieved by employing a mechanism that prevents private information from being displayed on public devices. Instead, this type of information is made available only to a user's personal device(s) that the user carries and/or trusts. An example embodiment of the invention shows relevant parts of the information content, referred to also as information documents or simply documents, to multiple devices based on privacy level and user preferences. Embodiments of the present invention also provide personalized services based on privacy levels defined by users. These users can for example be customers of a retail store. The service provided is sometimes also based on user history of accessing information documents. It permits personalized information to be sent to a customer's personal device.

Information content distribution based on privacy and/or personal information

The present invention provides shared communication medium capability to the plethora of computer devices, like the PCCAs, that normally are able to communicate with other devices via dedicated point-to-point links, e.g., via the practically universal RS-232 ports. It allows the sharing of the communication medium in a dynamic fashion depending on the instantaneous traffic demands by the various communicating devices. It further allows the emulation of point-to-point links over the shared communications medium in such a way that applications running on a PCCA use the shared medium transparently. Thus, this invention enables applications designed to operate over a point-to-point connection to operate over the shared medium without any modifications of the applications or the point-to-point devices. It enables the shared medium communications and dynamic communication resource allocation by using a device's I/O ports designed for point-to-point communications with dedicated communication resource allocation.

Providing shared-medium multiple access capability in point-to-point communications

The present invention provides a method, apparatus and computer product for a mobile device to roam securely and seamlessly from one access point to another access point without disrupting an active PPP connection. The method includes establishing, maintaining, and terminating a PPP connection between a mobile device and a PPP server via an access point, wherein the mobile device is equipped with a serial asynchronous communication interface. The PPP server is attached to a packet switched data network, and the access point is acting as a bridge between the serial communication interface and the packet switched communication interface. Also provided is a method to emulate a direct RS-232 cable connection between a mobile device and another computer located several hops away from the mobile device. It provides a method of keeping the RS-232 cable emulation between the mobile device an another computer system intact despite changes in mobile device's location in the network. It also provides a method of exchanging cookies between peers at the PPP connection establishment time and using them for fast reauthentication. This is a secure method of switching from one PPP proxy to another PPP proxy without disrupting the end to end PPP connection.

Method for seamless networking support for mobile devices using serial communications

Rate management in adaptive data rate wireless communication systems in which communicating stations move with respect to one another implements algorithms for calculation of the repetition rate. A rate management module is used for selecting a proper value of repetition rate to be communicated back to sending station and for a selecting proper value of repetition rate to encode the data at the sending station. The repetition rate calculation procedure enables each station to dynamically calculate the optimum rate with which each station should be receiving information from another station. The repetition rate calculation procedures take into consideration past and present measurements of the link quality, age of the link quality measurements, speed of change in the link quality, packet types, packet lengths, received signal strength, and pattern and correlation in the link quality measurements. The rate management module utilizes one or more tables which are accessible from either hardware or software.

Rate selection in adaptive data rate systems

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

Fairness algorithms and access methods enable non-zero channel access for wireless communication systems operating in a random access channel environment. Fair access to a random access channel for each station in a wireless network is assured by each station calculating a priority or probability for accessing the channel based on logical connections among certain stations, based on other stations perception of the channel and based on each calculating station's own perception of the channel properties.

Balanced media access methods for wireless networks

The throughput of a Request-to-Send and Clear-to-Send (RTS/CTS) based distributed media access control protocol is improved by reserving the medium in a hierarchical fashion. The shared medium is reserved for two stations called the participants. During the reserved period, a master (or primary) attribute and a slave (or secondary) attribute are given to the participants and the medium is shared between them using any suitable coordination algorithm. During the reserved time, the secondary can signal the primary station that it has data to send to the primary station and request that the primary and secondary roles or attributes be exchanged. In the case that a role exchange takes place, control of the medium is transferred from one station to another and data transfer in an opposite direction can take place without requiring another reservation. Observing stations which are not participating in the reservation can be invited to join the reservation as additional secondary stations if this does not cause any interference to any other existing reservations. The efficiency of the medium reservation may be improved also by piggy-backing any reservation specific signals onto data packets and by defining new response frames such as Hold-to-Send (HTS) and Free-to-Send (FTS) for flow control when there is a congested receiving station.

Extensions to distributed MAC protocols with collision avoidance using

In a wireless multi-rate communications system, a method for extending the range of communications in the system by dividing the physical layer frame into two portions: a robust header portion and a body, where the repetition rate of the data symbols in the header portion is greater than or equal to the repetition rate of the data symbols in the body of the frame. In this way the header can be received and decoded by all stations in the system with a high probability, while the body of the frame need only be received and decoded by the destination station to which the body of the frame is intended to be received and decoded.

Media access control protocols in a wireless communication network

A method of delievering data in a wireless communications network using a combination of collision sensing and collision avoiidance protocols. More precisely, if there are no hidden nodes detected in the network, a collision sensing protocol is used; however, if there are hidden nodes, then a collision avoidance protocol is used. This invention also deals with methods of determining the presence or absence of hidden nodes.

Schemes to determine presence of hidden terminals in wireless networks

Distributed call setup and rerouting are realized in a mobile-communications network. A connection tree is set up within the network, e.g., upon a mobile user accessing a base station. The connection tree comprises communication routes from a fixed point in the network, the root of the tree, to each base station within a vicinity of the base station accessed by the mobile user. When the mobile user moves from one cell to another within the connection tree, the call is rerouted to another route within the connection tree.

Method and apparatus for supporting mobile communications in

In communication systems which include high speed wired local area networks (LANs) and low speed wireless LANs, the bandwidth of the wireless LANs can be severely impacted. It has been found that many broadcast or multicast messages which are forwarded to the wireless LANs are not required as the mobile terminals which would receive the messages are not required to act on them. The present invention provides a means and method to filter out unneeded messages so that they do not impact the bandwidth of the wireless network. Each access point for each wireless LAN maintains a table of parameters for each associated mobile terminal in the connected wireless LAN. The parameters in that table are compared to the parameters in message frames received by the access point and only those messages having parameters found in the table are put on the wireless LAN. The level of filtering can be controlled by specifying which parameters are to be used for filtering messages. The tables at each access point are maintained current by moving table entries from access point to access point as mobile terminals move from wireless LAN to wireless LAN and by removing inactive table entries from the table when a predetermined interval of inactivity is encountered and a terminal is determined to be no longer in active contact with the access point.

Broadcast/multicast filtering by the bridge-based access point

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

Method and apparatus for supporting mobile communications in mobile

In a mobile communications network, cell-clusters are defined to include a multiplicity of cells. Wireless connections within the network are classified based on the actions taken for the connections when a radio congestion state is encountered. A cell-cluster controller controls admission of new calls to the cell-cluster, and admits or rejects the calls based on (1) number of existing calls of each class in the cell-cluster, (2) traffic characteristics including call holding time and a hand-off rate of each class, (3) quality-of-service (QOS) requirements of each class, and (4) policy for scheduling or sharing different call classes at each base station of the cell-cluster.

System and method for connection control in mobile communications

Growing community of inventors

Fishkill, NY, United States of America

Mahmoud Naghshineh