Title:
【発明の名称】パケットデータ通信システム
Document Type and Number:
Japanese Patent JP3429782
Kind Code:
B2
Abstract:
A packet data transmission system is used to link a number of remote hand-held data-gathering units such as bar code readers to a central computer which maintains a database management system. Data packets are sent from the remote units by an RF link to intermediate base stations, then sent by the base stations to the central computer by a serial link. Direct sequence spread spectrum modulation is used for the RF link. The remote hand-held units initiate an exchange using RF transmission to and from the base stations, receiving only during a rigid time window following a transmission from the remote unit. The base stations cannot initiate communication to the remote units, but instead send data to the remote units only as part of the exchange.
Inventors:
Laroy Teams
Application Number:
JP34613691A
Publication Date:
July 22, 2003
Filing Date:
December 27, 1991
Export Citation:
Assignee:
Symbol Technologies Inc.
International Classes:
G06K7/00; G06K17/00; H04B1/707; H04L1/16; H04L1/18; H04L5/14; H04L12/28; H04L12/56; (IPC1-7): H04L12/28; H04L12/40
Domestic Patent References:
| JP61270930A | ||||
| JP6171738A | ||||
| JP63198438A | ||||
| JP61281642A | ||||
| JP63138835A | ||||
| JP5541027A |
Attorney, Agent or Firm:
Minoru Nakamura (6 outside)
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