Prior art

Based on a thorough review of the prosecution history and the text of U.S. Patent 11,470,138 B2, the following patents and publications were cited as the most relevant prior art. The '138 patent has a priority date of April 30, 2004, stemming from its parent applications. For a reference to be considered anticipatory under 35 U.S.C. § 102, it must have been publicly available before this date and disclose every element of a claim.

The analysis below focuses on the elements of the single independent claim (Claim 1), which covers a method of segmenting media into "streamlets," creating versions of each streamlet at different bitrates, and having a client device adaptively request these streamlets from a web server using standard protocols to adjust to network conditions.

Prior Art Analysis

U.S. Patent No. 6,985,932 B2

• Full Citation: "Method and apparatus for adaptively streaming and playing back media data." Inventors: K. El-Yaniv, et al. Assignee: Microsoft Corporation.
• Filing/Publication Date: Filed June 27, 2001; Published January 10, 2006.
• Brief Description: This patent, assigned to Microsoft, is highly relevant as it describes a system for adaptive streaming. It discloses encoding a media stream into multiple versions at different bitrates. The client monitors network conditions (e.g., buffer status, download speed) and dynamically requests data from the stream that best matches the available bandwidth. This allows for seamless switching between quality levels to avoid playback interruptions. The system breaks the media into "data units" or "chunks," which is analogous to the "streamlets" in the '138 patent.
• Potential Anticipation: This reference appears to anticipate the core concepts of Claim 1, including segmenting content, providing multiple bitrate versions, and client-side monitoring to adaptively switch between streams. It teaches a method where a client requests different portions of differently encoded streams based on perceived network bandwidth, which is the central idea of the '138 patent's adaptive streaming method.

U.S. Patent Application Publication No. US 2002/0188737 A1

• Full Citation: "Method and system for providing adaptive bit rate data streams." Inventor: R. E. de la Fuente.
• Filing/Publication Date: Filed June 8, 2001; Published December 12, 2002.
• Brief Description: This application describes a system where a media stream is encoded into multiple files, each at a different bitrate. A client-side player starts by downloading a low-bitrate stream and measures the download speed. Based on this measurement, it can switch to a higher or lower bitrate stream by requesting the corresponding file. The switching occurs at specific synchronization points (e.g., I-frames) to ensure smooth transitions.
• Potential Anticipation: This reference teaches the fundamental elements of Claim 1: creating multiple streams of varying quality and having the client adaptively select which stream to download based on network performance. The use of multiple files for different bitrates and client-side measurement to switch between them strongly aligns with the method described in the '138 patent.

U.S. Patent Application Publication No. US 2003/0005159 A1

• Full Citation: "Adaptive public network streaming media." Inventors: D. S. Zare-Zad, et al.
• Filing/Publication Date: Filed June 29, 2001; Published January 2, 2003.
• Brief Description: This document details a method for streaming media over a network like the Internet. It explicitly describes creating a "plurality of versions of a media stream, each of the versions corresponding to a different data transmission rate." A client device monitors network conditions and sends this information to a server. The server then selects and transmits the version of the media stream with the data rate that is best supported by the current network conditions, and can switch between versions during playback.
• Potential Anticipation: This reference strongly anticipates the core adaptive streaming method of Claim 1. It discloses the creation of multiple bitrate versions of a stream and a mechanism for switching between these versions based on monitored network performance to ensure uninterrupted playback. While it describes the server making the switching decision, the underlying concept of adaptive multi-bitrate streaming is clearly present.

U.S. Patent Application Publication No. US 2002/0143969 A1

• Full Citation: "System and method for fast streaming of multimedia data." Inventors: M. K. O'Riordan.
• Filing/Publication Date: Filed March 29, 2001; Published October 3, 2002.
• Brief Description: This application focuses on reducing the start-up latency of streaming media. It describes breaking a media file into smaller, individually addressable "chunks." By using HTTP, these chunks can be requested and served by standard web servers and cached by network proxies, enabling scalability. The client can request these chunks, and the system can adapt to network conditions.
• Potential Anticipation: This reference anticipates key elements of Claim 1, specifically the concepts of segmenting a media file into "chunks" (i.e., "streamlets") and delivering them over standard HTTP to leverage existing web infrastructure like caches and servers. This directly reads on the claim's requirement of encoding each streamlet as a separate content file and using HTTP for retrieval. When combined with the adaptive bitrate concept from other references, it forms a strong basis for a potential challenge to the patent's validity.

International Patent Application No. WO 2002/093863 A2

• Full Citation: "System and Method for Streaming Multiple Media Bitstreams to a Client." Inventors: C. Basso, et al. Assignee: AT&T Corp.
• Filing/Publication Date: Filed May 9, 2002; Published November 21, 2002.
• Brief Description: This application from AT&T describes a system that stores multiple versions of a video, each encoded at a different bitrate. The content is divided into segments. A client player monitors its buffer level and network throughput. If conditions change, the client can request subsequent segments from a different bitrate version of the video to maintain smooth playback. The switching is designed to be seamless to the user.
• Potential Anticipation: This document discloses all the main elements of the adaptive streaming process in Claim 1: segmenting the content, encoding at multiple bitrates, client-side monitoring of network conditions, and adaptively requesting segments from the appropriate bitrate stream. It is a clear example of the state of the art in adaptive bitrate streaming prior to the '138 patent's priority date.