You can freely build on How Wireless Routers Manage Traffic Between Old and New Devices
This patent expired in 2023. Every claim — 0 independent, 1 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.
Original assignee
Lenovo Singapore Pte Ltd
Patent granted
2008
Expired
2023
Forward citations
1
What this patent covers
This patent describes a traffic management system for wireless access points that handle multiple Wi-Fi protocols, specifically 802.11b and 802.11g. Because 802.11b devices cannot 'see' the signals used by faster 802.11g traffic, they often transmit data at the same time, causing collisions and slowdowns. The invention uses a flow controller to maintain specific timers for each protocol. By delaying traffic from the slower protocol until the timer for the faster protocol expires, the access point ensures that high-speed data packets are not interrupted by legacy devices.
What is now free to use
All 1 claims of US 7352772 are in the public domain. Specifically:
The 1 dependent claim 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.
Does not cover network traffic management that relies solely on hardware-level signal filtering without software-based timers.
Does not cover protocols other than those utilizing physical vs. virtual carrier-sense mechanisms (like 802.11b/g).
Does not cover client-side traffic management; it is strictly limited to the access point (router) side.
Who is building on this today
The core principles of protocol isolation are now standard in modern Wi-Fi chipsets from companies like Qualcomm, Broadcom, and Intel. While this specific patent is older, the logic of managing mixed-speed traffic remains fundamental to how modern routers handle legacy IoT devices alongside high-speed Wi-Fi 6 clients.
Products built on expired version of this technology
Legacy Wi-Fi access points supporting mixed 802.11b/g environments
Early 2000s wireless routers from manufacturers like IBM or Lenovo
How to cite this patent in your documentation
Lenovo Singapore Pte Ltd. US Patent 7352772. Minimization of performance impact in overlying 802.11b and 802.11g networks. Granted 2008, expired 2023. 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.