A paging system is provided for transferring data and voice messages to a unique address of a paging receiver. The system includes a paging controller, an encoder, a transmitter, and a paging receiver. The paging controller receives voice and data information from an entry device. The encoder, coupled to the paging controller, encodes the voice and data information into a composite paging signal designated for the unique address of the paging receiver. The composite paging signal is transmitted ...

A digital tone detector utilizes pseudo sinusoidal quadrature reference signals in combination with a unique summation rule for summing the resultant quadrature accumulations to obtain a substantial improvement in the sidelobe responses of the filter. The digital tone detector also utilizes a "stepped" observation window to further provide a substantial improvement in the third harmonic response of the filter. The digital tone detector can be implemented using a hardware implementation, a combin...

An apparatus for controlling the illumination of a display used to prevent messages in a pager is described. A microcomputer is used for controlling the operation of the display in response to a read switch being actuated. A light switch, coupled to an illumination circuit provides display illumination upon the light switch being manually activated. The microcomputer also couples to the light switch to allow monitoring of the switch actuation. Upon actuation of the light switch, when a message i...

Apparatus and method is disclosed for storing and subsequently transmitting later messages for system pagers with acknowledge back capability that nevertheless fail to acknowledge back in the first instance. Addresses are retransmitted for pagers initially failing to acknowledge back on a continuous periodic basis until such acknowledge back is received, at which time the message intended therefor is sent, or a predetermined time period expires.

Delamination-resistant abrasive belts and discs suitable for offhand and automated article finishing comprise a lofty, non-woven, three-dimensional abrasive web adhesively bonded to a stretch-resistant woven fabric with a polyurethane binder comprising the reaction product of poly-1,4 oxybutylene) glycol diisocyanate having a molecular weight of about 500-4000 and a reactive compound capable of reacting with the isocyanate radicals. The reactive compound is selected from a group consisting of wa...

A method is provided for background scanning in a selective call communication system (102) having a plurality of channels (110, 112, 114), wherein a selective call device (104) has designated thereto one of an odd and even frame compulsory decoding schedule. The selective call device (104) decodes system configuration information (SCI) on odd SCI frames during the odd compulsory decoding schedule, scans for even SCI frames of target channels while maintaining the odd compulsory decoding schedul...

Bonded abrasive compositions, articles incorporating same, and methods of making the compositions and articles are presented, the compositions comprising abrasive particles dispersed throughout and adhered within an elastomeric polyurea matrix. The polyurea matrix is formed from the polymerization reaction product of a polyfunctional amine and an isocyanate. The compositions exhibit excellent smear- and wear-resistance, and may be attached to a variety of backings. One preferred backing is integ...

A radio frequency (RF) communication system transmits information including multiple data formats. The RF communication system receives the information (102) and parses the information into a plurality of nibbles (126), each of the nibbles comprising a predetermined number of bits. The plurality of nibbles are then provided to a terminal (10) as a message (154), the message is encoded by the terminal (10), and the encoded message is transmitted to a transmitter (15) for transmission therefrom.

An on-site selective call receiver interacts with a wide area selective call system to increase the probability of timely message reception by a selective call receiver capable of operating in either the wide area or the on-site selective call system. A frequency shifting signal is transmitted from the wide area system in response to addition of the selective call receiver to the on-site registry or automatic detection of entry of the selective call receiver into the on-site selective call syste...

An RF receiver having a coupling capacitor connected between the back end of the receiver and the input to a data limiter circuit, a battery saver strobe feature which periodically turns the receiver ON and OFF and a precharge circuit for precharging the coupling capacitor. The receiver further includes a reference voltage stabilization circuit which prevents a received signal from reaching the output of the back end of the receiver during the precharging of the coupling capacitor in order to mi...