US 7193986

Summary of U.S. Patent 7,193,986

Title: Wireless network medium access control protocol

Assignee: Arlington Technologies, LLC (current) / Nortel Networks Ltd. (at time of issue)

Inventors: William Giles Scanlon, Tze-Yeung Chui

Filing Date: May 30, 2002

Issue Date: March 20, 2007

Abstract:
A device for use in a packet-oriented transmission network comprises a transmitter arranged to transmit a sequence comprising at least one data packet and a receiver arranged to receive a sequence comprising at least one data packet. At least one data packet in one of the transmitted or received sequence of data packets includes at least one pointer to indicate when a designated data packet in the sequence is to be received and/or transmitted. The designated data packet includes an indication of at least one other device connected to the packet-oriented transmission network.

Plain-Language Overview of Independent Claims:

This patent introduces a method for managing communication in a wireless network that has one central "master" device (like a Wi-Fi router) and several "slave" devices (like laptops or smartphones). The core innovation is the use of "pointers" within data packets to improve efficiency and reduce power consumption for the slave devices.

Claim 1 describes the master device. In simple terms, this claim outlines a master device that sends out data packets in a timed sequence. Crucially, some of these packets contain a pointer that tells all listening devices when a special "designated packet" will be sent. This designated packet acts as a schedule, informing each participating slave device exactly when it is their turn to transmit information back to the master. This system allows slave devices to power down their receivers and save battery life, only waking up when they expect to receive the designated packet or their own specific data.

Claim 9 describes the slave device. This claim mirrors the master device's operation but from the perspective of a user's device. It details a slave device that is capable of receiving the data packets sent by the master. The slave device can read the pointer in these packets to know when to expect the important "designated packet." By reading this designated packet, the slave device learns which other devices are on the network and, most importantly, when it has been scheduled to send its own data. This allows the slave device to coordinate its transmissions and remain in a low-power "sleep" mode for much of the time, significantly extending its battery life.

Litigation and Reexamination:

As of April 2026, U.S. Patent 7,193,986 has been the subject of litigation and a USPTO ex parte reexamination. The patent is currently assigned to Arlington Technologies, LLC, which has asserted it in lawsuits against companies including T-Mobile. A search of the Court of Appeals for the Federal Circuit (CAFC) dockets for 2026 did not reveal an active appeal directly associated with this patent number, though district court litigation was initiated in 2025 (Case 2:25-cv-00279 in the Eastern District of Texas). Furthermore, in an ex parte reexamination proceeding, the USPTO has indicated its intent to issue a reexamination certificate that would cancel several of the patent's claims, including independent claim 1. This could significantly impact the patent's enforceability. I do not have authoritative information on the final outcome of the reexamination or any ongoing appeals.