International Business Machines Corporation

Peter Dirk Hortensius

Mahmoud Naghshineh

Claus Michael Olsen

Parviz Kermani

Babak Rezvani

Colin George Harrison

Danny N McKay

John Peter Karidis

Kadathur S Natarajan

Leon Lumelsky

Fritz R Gfeller

Krishna Sundaram Nathan

Anand Narasimhan

Gregory J Clary

Richard Francis Freitas

Robert Joseph Evans

Patrick K Kam

Thomas Allan Corbi

Siddhartha R Chaudhuri

Haaken B Winbom

Real time digitization of handwritten text and integration of digital recordation of handwritten text with traditional paper-based record making systems is achieved with a recording unit which may record a sequential data stream of strokes and associated events. The data stream may be stored in the apparatus and processed in accordance with various applications. Recordation of handwritten strokes may be accompanied by automatic detection and recordation of predefined events, and by user invoked generation of events. Recorded handwritten text may be processed to produce character strings or image data for text recorded in conjunction with predefined events.

Methods, systems and products pertaining to a digitizer for use in paper based record systems

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 gateway enables point to multipoint connectivity from voice, data, or SVD clients over voice and data networks. The gateway connects one or more known voice networks (e.g. telephone networks) and one or more data networks (e.g. LANs, WANs, and internet) so that clients on either network may access any of the networks via various devices like analog telephones, data modems, SVD modems, or direct data network connections (e.g., ethernet, token ring). The gateway has connections to both the data network(s) as well as the voice network(s). The gateway is capable of splitting a signal with both voice and data streams and routing either and/or both of these streams over the voice network alone, the data network, or both. A process, executing on the gateway enables the gateway to establish connections on gateway paths and to control and direct a flow of voice and data information between the destinations on these networks.

Multipoint simultaneous voice and data services using a media splitter gateway architecture

Apparatus and method for interfacing a wired communications network (12) to a wireless communications network (13). Both networks operate with a CSMA protocol. An interface unit (16) includes circuitry (28) for bidirectionally interfacing to the wired medium for transmitting messages thereto and for receiving messages therefrom. The interface unit also includes circuitry (29, 22, 24, 26) for bidirectionally interfacing to the wireless medium for transmitting messages thereto and for receiving messages therefrom. The interface unit further includes logic (28) for bidirectionally routing messages received from the wired medium to the wireless medium and for routing messages received from the wireless medium to the wired medium. A further feature of the interface unit is a collision detector (30), responsive to the reception of a rebroadcast wireless transmission, for comparing the transmitted message to the received rebroadcast message to determine if a collision has occurred.

Transceiver for extending a CSMA/CD network for wireless communication

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

Methods and apparatus for operating an optical communications system having at least two communicating entities (10,12). In accordance with a method of the invention a first step transmits communication link control information from a first entity to a second entity over a first optical channel having a first data bit rate. Responsive to the transmitted communication link control information, a second step of the method transmits data information from the second entity to the first entity over a second optical channel having a second data bit rate that is greater than the first data bit rate. The first optical channel is preferably a relatively low-bandwidth diffuse transmission infrared radiation channel. The second optical channel is preferably a relatively high-bandwidth infrared channel. One of the entities is a network adapter coupled to a wired network. The network adapter is preferably ceiling mounted. The other entity may be a mobile data processor. A plurality of mobile data processors may be served by one network adapter.

Control method and apparatus for wireless data link

A method for communicating information bidirectionally between a wired network (1) and a wireless network. The wireless network is of the type that includes header stations (12) each having a communication cell (2) associated therewith and one or more mobile communication units (10) disposed within the communication cell. The method includes a first step of, during a first portion of a wireless communication cycle, transmitting information over an uplink wireless communication channel from one or more of the mobile communication units to the header station. A second step of the method, accomplished during a second portion of the wireless communication cycle, transmits information over a downlink wireless communication channel from the header station to one or more of the mobile communication units. The information transmitted downlink includes frames of data received by the header station from the wired network. The first portion may be accomplished in part or in total by a CSMA protocol where the mobile units contend for access to the uplink communication channel. In one embodiment the header station initiates the first portion by transmitting to the header stations information for scheduling the sequence of the uplink transmissions.

Methods for polling mobile users in a multiple cell wireless network

Method and apparatus for coordinating a usage of a wireless transmission medium among a plurality of transmission units (12). The transmission medium is of a type that is utilized in accordance with a protocol having a transmission period that is comprised of a plurality of consecutively occurring transmission sub-periods. A method includes the following steps. A data structure (28a) is periodically circulated among the transmission units, the data structure being expressive of an identification of each of the transmission units and also expressive of an identification of an assigned transmission sub-period or sub-periods, if any, during which each of the transmission units is permitted to transmit on the wireless medium. The step of circulating includes the following steps: (a) receiving the data structure from a first transmission unit with a second transmission unit; (b) respsonsive to the receipt of the data structure at the second transmission unit processing the data structure in accordance with an amount, if any, of impending transmission activity to modify the assignments of sub-periods therein; and (c) transmitting the modified data structure to another one of the transmission units. A method of synchronizing the plurality of transmission units to a slotted transmission protocol is also disclosed.

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Goldens Bridge, NY, United States of America

Peter Dirk Hortensius