05157687 is referenced by 303 patents and cites 23 patents.

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.

Title
Packet data communication network
Application Number
374452
Publication Number
5157687
Application Date
December 19, 1990
Publication Date
October 20, 1992
Inventor
LaRoy Tymes
Palo Alto
CA, US
Agent
Arnold White & Durkee
Assignee
Symbol Technologies
NY, US
IPC
H04K 1/00
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