International Business Machines Corporation

Richard N Ames

Victor S Moore

Akram Bou-Ghannam

Andrew B McNeill

Joel C Leininger

Layton Balliet

Gerald U Merckel

Thomas K Pate

Joseph A Boscove

Richard V Ballou

George P Taylor

Peter Langer

William Craig Troop

Robert V Miller

Dick K Hardin

Stanley M Belyeu

Thomas W Kludt

Nicholas J Schwartz

Frederick T Slater

Stanford A Strickland

Methods and apparatus are set forth which enable a radio frequency data communications network (1) to perform decentralized uplink network control functions (decentralized away from the centralized general communications controller (GCC) level of the network hierarchy); (2) to minimize, or in some cases eliminate, the overhead expended in making power lever (signal strength) determinations and assessments at both the GCC and base station levels of the network hierarchy (for the purpose of managing uplink communications); and (3) to allow individual subscriber radios (terminals) to dynamically determine the most desirable base station to communicate with when exchanging information a host computer via a shared RF communication channel (the link between a terminal and the base station). Additionally, an illustrative radio frequency data communication network, built in accordance with the teachings of the invention as a modified version of an existing network, is described where the modified network incorporates the aforementioned methods and apparatus.

Method and apparatus for decentralizing uplink network control functions

A digital communication network has a plurality of remote terminals (RTs) which communicate with a plurality of base stations (BSs) by radio links operating at a single frequency. Each RT monitors the signal strengths of outbound messages and keeps an ordered table indicating which BSs produce the highest strength signals. At sign-on, an RT sends a message to the BS at the top of the list. The message includes the first predetermined number of entries at the top of the list. Each BS monitors the number of RTs it can hear and the number of users attached to each BS. The BS to which the sign-on message is sent then decides on the basis of signal strength, number of users attached, and BS coverage which BS should be attached to the particular RT and then notifies a communications controller. Such decision thus levels the workload. Each RT monitors errors and requests re-evaluation of attachment when the error rate for the BS to which it is attached exceeds a predetermined value.

Load balancing in a digital communications network using radio links

An advanced display system controller is described for use in automotive vehicles. The controller has electronic circuitry to allow it to be programmed to display monochrome or color graphics and text on an all-points-addressable display device such as a CRT or an Electro-Luminescent (EL) Flat panel. The display resolution and scan rates may be programmed differently depending on the display type and size. The vehicle operator controls the display system via a reconfigurable switch system (RSS), such as an Infrared Touch Panel or Mylar Touch Switch Matrix mounted over the face of the display. In addition, external discrete switches may also be attached to the controller. The controller includes a master microprocessor and a slave microprocessor with preferred partitioning of functions and communicates with other parts of the vehicle via two serial data communication links, a Random Access bus and a Poll/Response bus. The design of this controller allows the display characteristics and supported functions to be changed through reconfigurable hardware and software, allowing a broad range of applications in different model automobiles.

Display system for automotive vehicle

An interface comprising normal asynchronous I/O interface hardware in combination with certain additional synchronizing connections is provided between a microcoded central processing unit (CPU) and a microcoded secondary processor (such as a floating point processor) for enabling these processors to function conjointly under common timing control as though they were natively attached to each other insofar as the execution of their respective microcodes is concerned. The secondary processor shares the normal I/O interface with the I/O devices for data transfer purposes in such fashion that data can be transferred between any of the I/O devices and the CPU in cycle steal mode when the secondary processor is internally occupied with executing an operation delegated to it by the central processor, and when the secondary processor is ready to store data which it has produced, I/O data transfers in cycle steal mode can be made concurrently with data transfers between the secondary processor and the CPU on a demand multiplex basis. Coordinating signals are passed between the processors at certain steps during the execution of their respective microcodes to maintain these microcodes in proper timed relationship with each other.

Synchronous microcode generated interface for system of microcoded data

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Boca Raton, FL, United States of America

Richard N Ames