You can freely build on How Bluetooth Creates Wireless Networks with Unique Addresses

What this patent covers

This patent details a system for wireless devices, like early Bluetooth gadgets, to form a network. A 'master' device sends its unique address and a clock signal to 'slave' devices. This information dictates how the radio channel will 'hop' between frequencies, making it unique and secure for that specific network. The master then asks the slaves for their own addresses and who they can talk to (topology information). It uses this data to build a 'configuration tree,' which is like a map of the network, helping it figure out the best way to send messages between devices. For example, a master phone could use this to connect to headphones and a keyboard, understanding how they relate to each other in the network.

What is now free to use

All 0 claims of US 6590928 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 networks where the hopping pattern isn't based on a master device's unique address.

• Systems that don't use a clock signal from the master to control the timing of the frequency hops.

• Methods for building a network map that don't involve collecting addresses and 'first order' connection lists from slave devices.

• Forming a configuration tree that doesn't follow specific rules about how 'rings' of connections can include or exclude devices.

• Directly controlling a device's power settings or data transmission rates.

Who is building on this today

Qualcomm, Intel, and Broadcom, major chip manufacturers for wireless communication, have built extensively on the principles of frequency hopping and piconet formation described in this patent for their Bluetooth and Wi-Fi chipsets. Ericsson, as the assignee, also continues to be a significant player in wireless infrastructure and technology.

Products built on expired version of this technology

How to cite this patent in your documentation

Telefonaktiebolaget LM Ericsson AB. US Patent 6590928. Frequency hopping piconets in an uncoordinated wireless multi-user system. Granted 2003, expired 2017. 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.