Predicting infringement litigation case study: Sonos and Google

October 2 2020 Sonos is suing Google for infringement of ten of its patents, in relation to its Google Chromecast and Nest speakers, in two separate claims filed in January and September 2020. These patent cover a range of technologies in relation to the control and optimisation of networked speakers in a home environment.

The linked articles suggest a history of collaboration between Google and Sonos, at least before the litigation commenced, and that Google has counter-sued Sono for infringement of some of its patents. Here at Ambercite we will leave the confirmation of infringement to the courts, but we do claim to be able to predict the potential for patent litigation for a portfolio of patents.

So how did we go in this case?

We will answer this question by running three different queries - the reasons for this will hopefully become clear below.

1) Analysis based on the litigated Sonos patents

The simple way to answer this question is to take the litigated patents (found in the court papers provided in the two links above), and run a licensing search on these ten patents, for say patents filed in the last 10 years. In Ambercite this query takes seconds to prepare, and it will return 566 similar patent filings that meet the query below.

As sometimes happens with a company that has a large patent portfolio, many of the top ranked (most similar) patents are filed by Sonos itself. In the case, we are looking for other companies, so we will filter out these results using the filter in the owner column:

Once Sonos patents are filtered out, the top-ranked patent is this one:

Ambercite’s ownership data is pretty good, but like most patent databases is not 100% perfect, and in this case, the correct owner is in fact Google:

But this is only one patent. Our recommended approach is to export all of the patents into a spreadsheet, filter out patents with an Similarity Score of less than 1, make any ownership adjustments needed, and then using the pivot table function in Excel to create a graph of the top ranked patents by “Total Licensing Potential”. The resulting graph looks like this:

Google is #2 in this list, with only Bose in front. The top ranked Bose patent is shown below - it does appear to be similar to the Sonos technology (but once again, we will leave the judgement of patent infringement to others)

So in this case, an Ambercite analysis based on the litigated Sonos patents suggest that the Google may be a risk of a patent infringement lawsuit.

2) Analysis based on full Sonos patent portfolio

There is an alternative approach to this analysis, namely to analyse the whole of the Sono portfolio, rather than the known litigated patents. This what an IP manager for Sonos might do, prior to the litigation, as they may not sure which of their patents they will seek to enforce.

In fact, it is difficult to analyse the whole of the Sonos portfolio, as Ambercite has a limitation for a query of up to 200 patents - and Sonos has over 300 patent families with granted patents.

But what we can do is:

1) Rank these patent families by forward citation count (we used a conventional patent database to do this).

2) Download the highest ranked 200 patents , and copy these into the Ambercite query box, similar to what was shown above:

3) Copy the remaining patents into the hide box, as shown below.

Going through a similar process to that discussed above, we end up with a slightly different set of results - but Google is still right up there in the rankings:

So a different process, but a similar outcome.

More to the point, a licensing manager for Sonos could run through this process, come up with this list of names that includes Google near the top of this list, and then investigate the products being sold by these companies to see who else may need a license to the Sonos patents.

3) Finding which Sonos patents to litigate

Having run through the process shown in step 2) above, and having worked out that Google appeared to have very similar patent, you might ask ‘which of the 343 Sonos patent families should be investigated first for potential assertion against Google?’

One possible way of doing this is to take results of the search done above, and identify the patents filed by Google or Motorola Mobility (by applying a name filter on the Owner column). This will return five patents\:

If we look at these five patents, we see a range of Similarity Scores (third column above) ranging from 5800 down to 0.5. In this case, we might take the top three of these Google patents, based on their Similarity Score and subject matter, and then run a third Ambercite search based on these patents:

This search will return 250 results, with the top 19 patent families (and 128 out of these 250 patents in total) filed by Sonos. The top three of these patent families found are shown below:

Ambercite would suggest that an IP manager might start with the top ranked patent Sonos patent family shown above, review the claims of the various members of this patent family to see if Google may be infringing these patents, and then subsequently work their way downwards through this list.

In this case, the IP manager has already run through a process, and identified a list of patents to litigate. So how does our predicted list of Sonos patents to litigated match their list of patents which they have chosen to litigate - knowing that the list of litigated would have been based on many many many hours of careful analysis, including looking closely at Google products?

This matching is a bit tricky as Ambercite will always report the first granted US patent for a patent family, rather than for example a later family member being litigated, so we need to base this analysis based on the earliest granted US family member for each family. Also we need to take into account that some of patents litigated by Sonos include multiple family members in the same patent family. This is completely within the rules of patent litigation, but Ambercite analyses patents family by family.

But after taking all of this into account - the list of litigated Sonos patents (or a family member) shown in the very first query shown above (and copied below):

Fall into position’s # 1, 2, 4, 6, 8, 21 and 128 in the ranked list of Sonos patents found in the Ambercite query in this section 3).

So Ambercite did a pretty reasonable job of predicting which patent families could bit litigating.

Would you like to try Ambercite for yourself?

Ambercite offers trial license if you sign up yourself - but you will need a full licence to run through a process like is shown here. To obtain a license, please contact us via the link below - we will only be too happy to set you up, and provide any necessary support.