Abstract: A method and system for managing and allocating multiple communication resources to ensure relatively equal usage. The selection of the resource can be performed by retrieving a pointer value, and testing the resource associated with the pointer value monitoring the call duration over this resource and appropriately updating it's status (if the call duration is below the threshold, a bad call count for the channel is incremented. And when the bad call count exceeds the threshold the channel is marked as faulty). The pointer value as necessary to find a usable resource, and a usable resource is selected. The pointer value can be modified either before the testing of the initially-selected resource, or after the final selection of the usable resource.

Abstract: A system and method for reliable transmission of information using asynchronous transfer mode (ATM) through a noisy transmission path such as a wireless or satellite transmission link. To efficiently adapt ATM to such wireless links requires the ability to discern ATM cell addresses in a high noise environment. The system and method provides multiple redundant addressing to reduce or eliminate misrouting of ATM cells transferred through such a noisy transmission link. The multiple redundancy addressing realizes multiple virtual circuits to the same destination. The multiple redundant addresses for the circuits are within the error space of a principal address used for actual transmission. Thus, the most probable error patterns occurring in the ATM address field will change the principal address to a redundant address to the same destination, thus avoiding misrouting of the ATM cell.

Abstract: A buffer management system and method for use in an ATM switch that allows for data processing of variable bit rate (VBR) and constant bit rate (CBR) traffic using a common buffer memory. The buffer memory is broken down into data sub-queues, each of which is assigned an output and purge priority. ATM cells are allocated to a particular data sub-queue by matching the desired quality-of-service of the cells with the output and purge characteristics of each sub-queue. The system and method dynamically sizes the data sub-queues so as to be equal to the number of ATM cells in the data sub-queue. In addition, age and size ratio thresholds may be assigned to each data sub-queue to better distribute available bandwidth among the sub-queues, and to ensure that cells are not excessively delayed.

Abstract: A data protocol compatible with ATM data transmission systems that provides a frame format that allows for ATM cell transmission in a low speed, high noise link such as a radio link and further provides for reliable radio data communication in the ATM format through the provision of timing and control information. A TDMA implementation of the present protocol is suitable for reliable data communication between a single headend station and a plurality of mobile substations. The protocol format is such that simple and easy interconnection with standard ATM data communications systems can be made to allow for wide distribution of relevant data. The protocol is suitable for implementation in either software or low cost hardware.

Abstract: The track pad cursor positioning device and method simulate the movement of a track-ball cursor controller by generating directional light curtains which facilitate optical sensing of the velocity and direction of movement of a pointer across a tracking area to generate a cursor control signal as a function thereof to control cursor movement. If a pointer is sensed but there is no pointer movement relative to the tracking surface, no control signal to move a cursor is generated, but if the presence of a pointer is not sensed after a cursor control signal has been generated, then a cursor control signal is provided which results in continued movement but deceleration of the cursor. The track pad cursor positioning device provides a miniature package which may be incorporated as part of a personal computer keyboard.

Abstract: A device and method for detecting the potential level of the electromagnetic field present between a reference point and a test point of a living organism is disclosed. A reference electrode provides a first signal indicative of the potential level of the electromagnetic field at the reference point. A test electrode provides a second signal indicative of the potential level of the electromagnetic field at the test point. More than one test electrode and corresponding second signals can be employed. An analog-to-digital converter responsive to the first and second signals generates a digital signal as a function of the potential difference between the first and second signals. A processor provides an output signal indicative of a parameter or parameters of the living organism as a function of the digital signal. In addition, a low pass filter can be provided ahead of the analog-to-digital converter for filtering out undesired charges and alternating current signals from the first and second signals.