CSIRO's High-Frequency Wireless Network Technology

This 1996 patent from CSIRO describes a wireless local area network system that can send data reliably using radio waves above 10 GHz, even when signals bounce off walls.

What it 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 it doesn't cover

• —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

The clever bit

The invention's cleverness lies in its method for handling signal reflections, or 'multipath'. By ensuring data symbols are longer than the time difference between direct and bounced signals, the system can effectively 'see' through the echoes and reconstruct the original data, a significant hurdle for high-frequency wireless communication.

Why it matters

This patent is foundational for early high-speed wireless networking. It describes core technologies that enabled Wi-Fi to function effectively in real-world environments where signals reflect off surfaces. The techniques patented here were crucial for developing robust wireless local area networks that could compete with wired connections.

Real-world examples

• 1.Early Wi-Fi standards (IEEE 802.11)
• 2.High-speed wireless networking equipment