Abstract: In an illustrative embodiment of the present invention, a first channel is allocated for transmitting sporadically generated messages from multiple field units to a base station. The first channel is preferably divided into time slots in which a field unit transmits an access request message to the base station for establishing a communication link. In response to an access request message, feedback information is provided from the base station to multiple field units indicating whether a collision was detected on the first channel for a message transmitted in a previous time slot. In an instance when a collision is detected, the field unit will re-transmit an access request message at a previous power level setting based on a random back off time.

Abstract: The performance of a RAKE receiver for indoor multipath WLAN applications on direct sequence spread spectrum signals having relatively short codeword lengths is enhanced by embedding a decision feedback equalizer structure in the signal processing path through the receiver's channel matched filter and codeword correlator. The decision feedback equalizer serves to cancel both inter-codeword interference (ISI) or ‘bleed-over’ between codewords, and intra-codeword chip interference (ICI) or smearing of the energy within the chips of a respective codeword.

Abstract: An RF communication system is for operating in the presence of a repetitive RF interference source powered from an Alternating Current (AC) power line. The system uses redundant transmission synchronized to the power line to ensure accurate reception by at least one second device. The RF communication system includes a first device powered from an AC power line which also powers the repetitive RF interference source. The first device, in turn, preferably includes an RF transmitter for transmitting in a frequency band of the repetitive RF interference source, a power line sensor, and a data transmit controller. The data transmit controller generates a plurality of data packets with each data packet including an error detecting portion. The data transmit controller also operates the RF transmitter to produce repetitive first and second transmissions of a same data packet responsive to the power line sensor.

Abstract: The combination of a thermoplastic polymer and a thermosetting polymer, provides a pigment system for producing coated printing papers. The thermoplastic polymer and thermosetting polymer, suspended in well-known coating binders and carriers, is applied to the web substrate on a standard paper machine. The amount of thermoset, preferably at least about 25% by weight of the pigment solids, improves ink receptivity and allows adjustable control of finished paper gloss. The amount of thermoset added to the pigment system is limited, however, preferably below about 75% by weight of the pigment solids, so that the finished printing paper obtains a Gardner 75.degree. gloss of at least about 40, at calendering pressures of less than 500 PLI.

Abstract: The speed of an engine driven pump is sensed and compared with the desired maximum operating speed to detect overspeed. The discharge of the pump is controlled by a variable flow rate controller. When an overspeed condition exists, a command signal is sent to the discharge controller to reduce flow by a discrete decrement. The control signal is blocked after activating the controller for a preselected time interval. During the blocking interval the engine speed is maintained substantially at the operating speed by cyclical reduction of the power input thereto.

Abstract: A method and apparatus for delivering constant water flow rates to the fire hose of a pumper truck at each of a plurality of selectable flow rate settings including the steps of transmitting a digital signal corresponding to a particular fire hose and pumper truck, receiving and decoding the digital signal, activating a multi-position valve in response to the decoded signal to set a particular valve position, and maintaining a constant flow rate to the fire hose by automatically varying the valve position in response to changes in the output pressure of the pump and pressure drop in the fire hose.