Report from the Second Screen Working Group PAG

Status of this document

This report was approved by the second Second Screen Working Group Patent Advisory Group (PAG) on 24 August 2026. Questions and comments on this report should be sent to W3C's legal team at team-legal@w3.org.

Executive summary

The goal of the W3C Patent Policy is to assure that Recommendations produced under this policy can be implemented on a Royalty-Free (RF) basis. W3C forms Patent Advisory Groups (PAGs) when patent claims are asserted against or expressly excluded from royalty-free commitment for implementations of W3C Recommendations.

In September 2025 W3C launched the second Second Screen Working Group Patent Advisory Group (PAG) in response to patent disclosures and exclusions by Apple, Inc on 01 May 2025 (the "Disclosed Patents") claimed to bear relevance to the Open Screen Application Protocol specification.

The PAG concludes that the excluded claims do not read on the Open Screen Application Protocol or they are covered by the prior-art in the US Patent 7,418,472 B2 that expired on 14 March 2026. It recommends that the Open Screen Application Protocol continues its path towards Recommendation without further change..

Contents

Procedure and timeline

This section traces the procedural steps that led to the publication of this report.

Analysis

The second Second Screen PAG noted that the re-chartered Second Screen Working Group had discontinued work on the Open Screen Protocol. Instead, the subject matter was split up into the Open Screen Application Protocol and the Open Screen Network Protocol. It is notable that the exclusions were directed only against the Open Screen Application Protocol. As Apple is a Member of the Working Group, their Patent Policy Royalty Free commitments apply to the Open Screen Network Protocol.

The first Second Screen PAG saw a much larger exclusion. A slight change removed most of Apple's concerns. The current three excluded patents were already under scrutiny in the first Second Screen PAG. The analysis of the first PAG still stands concerning the Open Screen Application Protocol.

The PAG analyzed the excluded independent claims in comparison to the Open Screen Application Protocol specification, taking also prior art into account. Compared to the first Second Screen PAG, the evaluation verified whether the relevant elements for the first analysis were still present in the new Open Screen Application Protocol Specification. After evaluation of the first Second Screen PAG report and its application to the Open Screen Application Protocol Specification, the PAG concludes that the Open Screen Application Protocol specification does not require the claim elements of which terms are bolded in the chart below.

In addition, the PAG identified references in the prior art, including U.S. Patent No. US 7,418,472 B2, the Sony Portable MiniDisc Player MZ-NH600D, and a published research paper “Low-Complexity Video Coding for Receiver-Driven Layered Multicast”. Note that the US Patent 7,418,472 B2 expired on 14 March 2026

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Patent disclosures

Disclosed patents and excluded claims are listed and analyzed below. All disclosed rights are issued patents.

Group 1 claims

Priority date asserted: 2004-04-27, set to expire on 2027-08-07

US 8,095,716 (claims 19-22, 25, 26)

Version on Google Patents: US 8,095,716

Excluded claim Evaluation
19. A method for use in an accessory, the method comprising:
establishing communication with a media player; and
sending capability information to the media player, wherein the capability information includes a plurality of information items selected from a group consisting of:
an information item identifying information capabilities of the accessory;
an accessory name;
a minimum version of media player firmware supported by the accessory;
a minimum version of a command set supported by the accessory;
an accessory firmware version;
an accessory hardware version;
an accessory manufacturer;
an accessory model number;
an accessory serial number; and
a maximum incoming packet size supported by the accessory.
The claim is not essential to implement the Open Screen Application Protocol because the capability exchange mechanism defined in the specification does not have a plurality of information items in common with the group described in the claim. The only information item in common is the accessory name. The Open Screen Application Protocol does not include provisions to exchange information capabilities, version numbers, manufacturing information, or a maximum incoming packet size.
20. The method of claim 19 further comprising receiving a request for capability information from the media player.
Claim depends on claim 19, which is non-essential to implement the Open Screen Application Protocol.
21. The method of claim 19 further comprising:
receiving a media player model identifier from the media player; and
selecting the capability information to be sent to the media player, the selection being based at least in part on the media player model identifier.
Claim depends on claim 19, which is non-essential to implement the Open Screen Application Protocol.
22. The method of claim 19 wherein establishing communication with the media player includes establishing a physical connection to the media player.
Claim depends on claim 19, which is non-essential to implement the Open Screen Application Protocol.
25. An accessory for use with a portable media player, the accessory comprising:
an interface configured to communicably couple the accessory to a portable media player; and
control logic coupled to the interface and configured to exchange commands and associated data with the portable media player via the interface,
wherein the commands include a first command sendable by the accessory to the portable media player, the first command providing one of a plurality of sendable information items, wherein the plurality of sendable information items includes at least two items selected from a group consisting of:
an information item identifying information capabilities of the accessory;
an accessory name;
a minimum version of media player firmware supported by the accessory;
a minimum version of a command set supported by the accessory;
an accessory firmware version;
an accessory hardware version;
an accessory manufacturer;
an accessory model number;
an accessory serial number; and
a maximum incoming packet size supported by the accessory.
Similar to claim 19, the claim is not essential to implement the Open Screen Application Protocol because the capability exchange mechanism defined in the specification only has one information item in common with the group described in the claim: the accessory name. The Open Screen Application Protocol does not include provisions to exchange information capabilities, version numbers, manufacturing information, or a maximum incoming packet size.
26. The accessory of claim 25 wherein the commands further include a second command receivable by the accessory from the portable media player, the second command requesting information from the accessory and specifying one of the plurality of sendable information items as being requested.
Claim depends on claim 25, which is non-essential to implement the Open Screen Application Protocol.
Analysis against the Open Screen Application Protocol of excluded claims from US 8,095,716
US 8,370,555 (claims 10, 11, 19, 20, 23, 25)
Version on Google Patents: US 8,370,555
Excluded claim Evaluation
10. A portable media player for use with an accessory, the portable media player comprising:
an interface configured to communicably couple the portable media player to an accessory; and
control logic coupled to the interface and configured to exchange commands and associated data with the accessory via the interface,
wherein the commands include a first command receivable by the portable media player from the accessory, the first command providing one of a plurality of information items, wherein the plurality of information items includes at least one item selected from a group consisting of:
a minimum media player firmware version supported by the accessory;
an indication of one or more command sets supported by the accessory; and
for each command set supported by the accessory, a minimum command set version supported by the accessory.
See prior art.
11. The portable media player of claim 10 wherein the plurality of information items further includes:
an accessory name;
an accessory firmware version; and
an accessory hardware version.
See prior art.
19. A method for use in a portable media player, the method comprising:
establishing communication with an accessory; and
receiving capability information from the accessory, wherein the capability information includes a plurality of information items selected from a group consisting of:
an information item identifying information capabilities of the accessory;
an accessory name;
a minimum version of media player firmware supported by the accessory;
a minimum version of a command set supported by the accessory;
an accessory firmware version;
an accessory hardware version;
an accessory manufacturer;
an accessory model number;
an accessory serial number; and
a maximum incoming packet size supported by the accessory.
The claim is not essential to implement the Open Screen Application Protocol because the capability exchange mechanism defined in the specification does not have a plurality of information items in common with the group described in the claim. The only information item in common is the accessory name. The Open Screen Application Protocol does not include provisions to exchange information capabilities, version numbers, manufacturing information, or a maximum incoming packet size.
20. The method of claim 19 further comprising sending a request for capability information to the accessory.
Claim depends on claim 19, which is non-essential to implement the Open Screen Application Protocol.
23. The method of claim 20 wherein the request for capability information specifies one of the plurality of information items as being requested.
Claim depends on claim 20, which is non-essential to implement the Open Screen Application Protocol.
25. A portable media player for use with an accessory, the portable media player comprising:
an interface configured to communicably couple the portable media player to an accessory; and
control logic coupled to the interface and configured to exchange commands and associated data with the accessory via the interface,
wherein the commands include a first command receivable by the portable media player from the accessory, the first command providing one of a plurality of information items, wherein the plurality of information items includes at least two items selected from a group consisting of:
an information item identifying information capabilities of the accessory;
an accessory name;
a minimum version of media player firmware supported by the accessory;
a minimum version of a command set supported by the accessory;
an accessory firmware version;
an accessory hardware version;
an accessory manufacturer;
an accessory model number;
an accessory serial number; and
a maximum incoming packet size supported by the accessory.
Similar to claim 19, the claim is not essential to implement the Open Screen Application Protocol because the capability exchange mechanism defined in the specification only has one information item in common with the group described in the claim: the accessory name. The Open Screen Application Protocol does not include provisions to exchange information capabilities, version numbers, manufacturing information, or a maximum incoming packet size.
Analysis against the Open Screen Application Protocol of excluded claims from US 8,370,555
Prior art

U.S. Patent No. US 7,418,472 B2: Shoemaker et al., “Systems and methods for determining remote device media capabilities”, assigned to Microsoft

  • Shoemaker describes systems and methods for receiving information about a media device’s capabilities and providing media based on that information
  • Priority date: 30 September 2003
  • Version on Google Patents: US 7,418,472 B2

Group 2 claims

Priority date asserted: 2004-10-25, set to expire on 2027-03-26

US 7,706,637 (claims 1-8)
Version on Google Patents: US 7,706,637
Excluded claim Evaluation
1. A method of operating a host to which a portable media player device is coupled for communication and interoperation therewith, comprising:
receiving, from the portable media player device, particular parameters characterizing the portable media player device; and
configuring the operations carried out by the host according to the received particular parameters to communicate and interoperate with the portable media player device.
See prior art.
2. The method of claim 1, wherein:
the host communicating and interoperating with the portable media player device includes processing and providing media to the portable media player device for playback thereon.
See prior art.
3. The method of claim 2, wherein:
the received particular parameters characterizing the portable media player device include particular parameters characterizing the playback of media by the portable media player device.
See prior art.
4. The method of claim 2, wherein:
the host operating according to the received particular parameters includes processing the media provided to the portable media player device based on the received particular parameters.
See prior art.
5. The method of claim 4, wherein:
the received parameters characterizing the playback of media by the portable media player device includes particular parameters characterizing a transformation inherent in the playback of media by the portable media player device.
See prior art.
6. The method of claim 5, wherein:
configuring the media provided to the portable media player device based on the received particular parameters includes transforming the media such that the transformation inherent in the playback of media by the portable media player device yields no substantial net effect.
See prior art.
7. The method of claim 1, wherein:
receiving, from the portable media player device, particular parameters characterizing the portable electronic media player device includes receiving the particular parameters as values associated with metadata corresponding to a meaning of the values.
See prior art.
8. The method of claim 7, wherein:
the step of operating the host software according to the received particular parameters includes processing the metadata to determine the meanings of the values.
See prior art.
Analysis against the Open Screen Application Protocol of excluded claims from US 7,706,637
Prior art

Commercial product: Sony Portable MiniDisc Player MZ-NH600D

  • The Sony MiniDisc MZ-NH600D allowed a user to connect a media player capable of storing different types of media to a computer, would recognize the media type, and configure its operations accordingly
  • Commercial availability date: April 2004
  • Online version of user manual (PDF): MZ-NH600D

Considerations in reaching the conclusions

The analysis provided in this report is neither exhaustive, nor intended to be.

Conclusions

The PAG concludes that the excluded claims do not read on the Open Screen Application Protocol or they are covered by the prior-art in the US Patent 7,418,472 B2 that expired on 14 March 2026.

Recommendations

The PAG recommends that the Open Screen Application Protocol continues its path towards Recommendation without further change.

Disclaimer

None of the authors is your attorney. No part of this report is intended as legal advice either to W3C or to its members. It is intended merely as a summary of what the PAG has learned to date. Rely on this report entirely at your own risk. This analysis includes the personal opinions of the authors.

THESE RECOMMENDATIONS OF THE SECOND SCREEN WORKING GROUP PATENT ADVISORY GROUP ARE NOT LEGAL ADVICE. NEITHER W3C NOR ANY OF THE PARTICIPANTS OF THIS PATENT ADVISORY GROUP OR THEIR RESPECTIVE EMPLOYERS TAKES ANY RESPONSIBILITY FOR THE ACCURACY, LEGAL CORRECTNESS OR OTHER FITNESS FOR ANY PURPOSE OF THE INFORMATION PROVIDED IN THIS REPORT. ESPECIALLY, NEITHER W3C NOR ANY OF THE PARTICIPANTS OF THIS PATENT ADVISORY GROUP OR ANY OF THEIR RESPECTIVE EMPLOYERS MAKE ANY REPRESENTATION THAT FOLLOWING THE RECOMMENDATIONS HERE WILL AVOID AN INFRINGEMENT OF ANY PATENTS MENTIONED IN THE REPORT.


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