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US 5487069Freedom to Build
Public domain since 2013

You can freely build on CSIRO's High-Frequency Wireless Network Technology

This patent expired in 2013. Every claim — 0 independent, 0 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.

Original assignee

Commonwealth Scientific and Industrial Research Organization CSIRO

Patent granted

1996

Expired

2013

Forward citations

120

What this patent covers

This patent covers a wireless local area network (LAN) system designed to work even when radio signals bounce around, a common issue in indoor spaces. It uses transceivers, which are devices that can both send and receive signals. These transceivers operate at radio frequencies higher than 10 GHz. The key innovation is how they process data: they break the data into smaller pieces called symbols. The duration of each symbol is made longer than the expected delay caused by bounced signals. This technique, along with methods to improve data reliability like error correction and interleaving data blocks, ensures that data can be transmitted and received accurately despite signal reflections. The system includes hub transceivers that connect to data sources and destinations, and mobile transceivers that connect to computers or other processing devices.

What is now free to use

All 0 claims of US 5487069 are in the public domain. Specifically:

    The 0 dependent claims add narrowing limitations and are also free.

    What is NOT covered

    Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.

    • Wireless systems operating at frequencies below 10 GHz

    • Wireless systems that do not specifically address multipath transmission environments

    • Methods of transmitting data that do not involve breaking data into symbols longer than expected signal delay times

    • Wireless systems that do not include data reliability enhancement techniques like Forward Error Correction or interleaving

    Who is building on this today

    The core technologies described in this patent were licensed by CSIRO to various companies, and they formed the basis for the development of Wi-Fi. Many companies in the telecommunications and consumer electronics sectors, including those that developed early Wi-Fi chipsets and routers, built upon this foundational intellectual property.

    Products built on expired version of this technology

    Early Wi-Fi standards (IEEE 802.11)

    High-speed wireless networking equipment

    How to cite this patent in your documentation

    Commonwealth Scientific and Industrial Research Organization CSIRO. US Patent 5487069. Wireless LAN. Granted 1996, expired 2013. Now in the public domain.

    Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.

    PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.

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