Abstract: A two-way data network includes a broadcast control sub-network and a cellular data sub-network. The broadcast control sub-network includes a few high-power radio transmitters broadcasting into a large service area. The cellular data sub-network covers the large service area by a number of base stations each servicing a relatively small area. The wireless terminals of the two-way data network monitors the messages in a broadcast control channel at pre-assigned periodic time slots and remain in "sleep" mode at other times. A packet radio transceiver in the wireless terminal sends data to, and receives data from, the cellularized base stations. The broadcast control sub-network is used to notify the subscriber the receipt of a message. In responding to the notification, the location of the subscriber's wireless terminal is make known, thereby eliminating conventional tasks such as location and mobility management tasks and allowing wireless terminals to be low power.

Abstract: A base station is configured including an internal bus to connect a terminal section, transceivers that perform control and management of information to be transmitted or received and carries out radio communication at a predetermined radio frequency and on a predetermined communication method, and a controller connecting section that executes communication with a base station controller. The transceivers each comprise a transmitter/receiver section that transmits and receives radio waves at a predetermined radio frequency and using a predetermined communication method, and a logical control unit that performs control of the transmitter/receiver section and interference detection.

Abstract: A customer information terminal for use in a retail grocery store includes a housing defining an interior region, electronic circuitry including a microprocessor supported within the housing interior region, and a display screen supported by the housing and electrically coupled to the electronic circuitry. The customer information terminal further includes a dataform reader module supported by the housing and electrically coupled to the electronic circuitry for reading a dataform having encoded data relating to at least one of the following; an item offered for sale in the retail grocery store, a coupon for an item offered for sale in the retail grocery store, a customer identification number of a customer of the retail grocery store, and a recipe utilizing one or more items offered for sale in the retail grocery store.

Abstract: A system which phase modulates a carrier to produce a carrier signal which transitions in phase between predetermined phase states as a function of the data, wherein a rate at which the carrier signal changes phase during a transition between the predetermined phase states varies substantially sinusoidally. The phase modulation provides a constant amplitude modulated waveform having low side lobes. Such modulation method preserves the high noise tolerance capabilities associated with FH systems and the high data throughput capabilities of DS systems.

Abstract: A network communication system in which access points providing wireless access to the system reroute misrouted information packets in the event the location of a mobile unit has changed. Regardless of whether a host computer or other network device is capable of updating in its position table the changing locations of the mobile units, information packets directed to the mobile units from the host computer or other network device are still properly delivered.

Abstract: A network access scheme enhances channel utilization under the ALOHA protocol by making use of the FM capture effect. The resulting network access scheme allows a transmitter to transmit a message simultaneously with other transmitters to a receiver without the need for retransmission when the message reaches the receiver with sufficient strength over the strengths of the other transmissions. In one embodiment, the network access scheme is applied to a wireless data network, which includes support to a two-way paging application. Another network access scheme combines the high channel utilization of the carrier sensing multi-access (CSMA) protocol with the FM capture effect to provide even higher expected channel utilization. The resulting network access scheme uses a channel access protocol ("CSMA/AT") which provides an adaptive threshold. An RF transmitter determines, using the adaptive threshold, whether or not to transmit its message.

Abstract: A method for selecting a symbol using an M-key keyboard in a personal information device (PID) divides the M keys into a first key group and a second key group. Each symbol to be recognized from the input key-strokes on the keyboard is assigned a unique two-keystroke sequence in which the first key and the second key of that two-keystroke sequence are selected from different key groups. When receiving keystrokes from the keyboard, two-keystroke sequences received from the keyboard are matched to the symbol assignments to derive which symbol is selected. This method is applicable not only for selecting letters from a European alphabet, such as the English or the Cyrillic alphabets, this method is applicable to selecting from a phonetic alphabet, such as the Pin-Yin system for Chinese characters and other phonetic systems in the Korean and Japanese languages as well.

Abstract: A shielding assembly for a PC board having ground trace segments on a surface of the board is disclosed. The shielding assembly includes a cover, shielding assembly, a sealing gasket and a fastener. The cover includes an integrally molded base portion and a fencing portion extending outwardly from a surface of the base portion. The fencing includes peripheral edges configured to overlie the ground trace segments. The sealing gasket is disposed between the fencing and the ground trace segments. The fastener mechanically couples the cover to the PC board surface.