摘要:
A data collection network supporting 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 within 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 critical, the system clock frequency is increased.
摘要:
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, in turn, communicate with one or more 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 and an adapter which has a simulcast and sequential mode provide selective interface between host computers and base transceivers. A scheme for routing data through the communication system is also disclosed wherein the intermediate base stations are organized into an optimal spanning-tree network to control the routing of data to and from the RF terminals and the host computer efficiently and dynamically. Additionally, redundant network and communication protocol is disclosed wherein the network utilizes a polling communication protocol which, under heavy loaded conditions, requires that a roaming terminal wishing to initiate communication must first determine that the channel is truly clear by listing for an entire interpoll gap time. In a further embodiment, a criterion used by the roaming terminals for attaching to a given base station reduces conflicts in the overlapping RF regions of adjacent base stations.
摘要:
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, in turn, communicate with one or more 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 and an adapter which has a simulcast and sequential mode provide selective interface between host computers and base transceivers. A scheme for routing data through the communication system is also disclosed wherein the intermediate base stations are organized into an optimal spanning-tree network to control the routing of data to and from the RF terminals and the host computer efficiently and dynamically. Additionally, redundant network and communication protocol is disclosed wherein the network utilizes a polling communication protocol which, under heavy loaded conditions, requires that a roaming terminal wishing to initiate communication must first determine that the channel is truly clear by listing for an entire interpoll gap time. In a further embodiment, a criterion used by the roaming terminals for attaching to a given base station reduces conflicts in the overlapping RF regions of adjacent base stations.
摘要:
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, in turn, communicate with one or more 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 and an adapter which has a simulcast and sequential mode provide selective interface between host computers and base transceivers. A scheme for routing data through the communication system is also disclosed wherein the intermediate base stations are organized into an optimal spanning-tree network to control the routing of data to and from the RF terminals and the host computer efficiently and dynamically. Additionally, redundant network and communication protocol is disclosed wherein the network utilizes a polling communication protocol which, under heavy loaded conditions, requires that a roaming terminal wishing to initiate communication must first determine that the channel is truly clear by listing for an entire interpoll gap time. In a further embodiment, a criterion used by the roaming terminals for attaching to a given base station reduces conflicts in the overlapping RF regions of adjacent base stations.
摘要:
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.
摘要:
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, in turn, communicate with one or more 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 and an adapter which has a simulcast and sequential mode provide selective interface between host computers and base transceivers. A scheme for routing data through the communication system is also disclosed wherein the intermediate base stations are organized into an optimal spanning-tree network to control the routing of data to and from the RF terminals and the host computer efficiently and dynamically. Additionally, redundant network and communication protocol is disclosed wherein the network utilizes a polling communication protocol which, under heavy loaded conditions, requires that a roaming terminal wishing to initiate communication must first determine that the channel is truly clear by listing for an entire interpoll gap time. In a further embodiment, a criterion used by the roaming terminals for attaching to a given base station reduces conflicts in the overlapping RF regions of adjacent base stations.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A portable, hand-held data collection terminal unit is of modular structure including among other modules a display screen module, a keyboard module and a base module, each of which may be chosen from a plurality of modules available for assembly into the terminal unit. Consequently, a wide combination of terminal units may be assembled from a comparatively limited number of modular choices, such that the cost of assembly of a terminal unit with specific functions may be minimized. A particular selected module is a scanning module including a pivotable scanning head to permit a user to adjust the scanning head to a convenient position for operating the scanning module without sacrifice of visual access to a display screen of the display screen module. The display screen module may be selected from modules of standard width equal to the width of the terminal unit, of extended width extending when assembled to a selected keyboard module beyond either or both lateral edges of the terminal unit. The selected display screen module may include one of different sized screens, function keys and alphabetical keys.