초록 ▼

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 term

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.

대표청구항 ▼

[ What is claimed is:] [1.] A radio frequency data communication system that supports data collection within a premises, the radio frequency data communication system comprising:a plurality of roaming terminals operational within the premises;one or more base stations, each having a radio frequency

[ What is claimed is:] [1.] A radio frequency data communication system that supports data collection within a premises, the radio frequency data communication system comprising:a plurality of roaming terminals operational within the premises;one or more base stations, each having a radio frequency transceiver, located within the premises;each of the one or more base stations transmitting a pending message list at each of selected time intervals;each of the plurality of roaming c terminals comprising a data collection system having a battery power supply and a radio frequency transceiver;the plurality of roaming terminals selectively communicative with the one or more base stations; andeach of the plurality of roaming terminals selectively deactivating the radio frequency transceiver through a plurality of the selected time intervals, and synchronizing the activation of the radio frequency transceiver to receive the pending message list following the plurality of the selected time intervals.