Norand Corporation

Gary N Spiess

Ronald L Mahany

Arvin D Danielson

Guy J West

Keith K Cargin, Jr

Ronald E Luse

Charles D Gollnick

Robert G Geers

Marvin L Sojka

Richard C Arensdorf

John G Pavek

James D Cnossen

Mary L Detweiler

Amos D Young

Robert Charles Meier

A data collection network supports roaming terminals which may enter and exit a sleep mode to conserve power. A plurality of base stations each periodically transmit pending message indications to those roaming data collection terminals in range. Instead of requiring the transceiver within each terminal to always be active, the receiver is activated in synchrony with the transmissions of pending message indications from at least one of the base stations. Otherwise, the terminal may deactivate the transceiver, i.e., place it in a sleep state. The terminal may also sleep through pluralities of transmissions of pending message indications, and, thereafter, awake in synchrony to receive subsequent pending message indications. To minimize noise, the terminal may operate using a lower frequency system clock when not collecting data. When collecting data, especially where processing time proves more critical, the system clock frequency is increased.

Network supporting roaming, sleeping terminals

An adaptive display refresh and data compression solution for use in an RF network environment is described, where a network controller and portable terminals maintain an adaptive history of commonly used past information in order that it may be repeated quickly and communication speeds can be increased. A network controller maintains a separate history for each of the terminals in the RF network, and transmits a coded reference for the activities that are contained in the history, which is stored in the memory of both the controller and the portable terminal. Terminals and the controller additionally may negotiate to determine the data compression features which will be supported in communication between the two devices. Data is compressed according to the present invention by utilizing a hybrid run length and sliding dictionary compression scheme. Data is pre-compressed by a run length compressor, and is further compressed by a specialized sliding dictionary technique designed to minimize memory storage and transmission time requirements, resulting in an efficient data compression method requiring little additional storage.

Adaptive display refresh and data compression in a radio frequency

Improved apparatus for a radio communication system having a multiplicity of mobile transceiver units selectively in communication with a plurality of base transceiver units which communicate with one or two host computers for storage and manipulation of data collected by bar code scanners or other collection means associated with the mobile transceiver units. A network controller provides selective interface means to be employed between the host computers and the base transceivers whereby low data rate base transceivers may be utilized with the network controller while spread spectrum or high data rate networked base transceivers may be also utilized. The network controller may allow selection of interface means for three of its ports from its front panel with use of three input keys. The network controller is entirely external to the host computer or computers, and can couple to a variety of commonly encountered host ports. Most preferable one- or two-network controller ports can each be software configured to match any needed host port, so that the host computer(s) need not be adapted to a radio network protocol accommodating the multiple base transceiver units.

System for coupling host computer meanswith base transceiver units on a

Network utilizing a controller and base transceivers to route voice

An adaptive display refresh and data compression solution for use in an RF network environment is described, where a network controller and portable terminals maintain an adaptive history of commonly used past information in order that is may be repeated quickly and communication speeds can be increased. A network controller maintains a separate history for each of the terminals in the RF network, and transmits a coded reference for the activities that are contained in the history, which is stored in the memory of both the controller and the portable terminal. Terminals and the controller additionally may negotiate to determine the data compression features which will be supported in communication between the two devices. Data is compressed according to the present invention by utilizing a hybrid run length and sliding dictionary compression scheme. Data is precompressed by a run length compressor, and is further compressed by a specialized sliding dictionary technique designed to minimize memory storage and transmission time requirements, resulting in an efficient data compression method requiring little additional storage.

Growing community of inventors

Lisbon, IA, United States of America

Gary N Spiess