I was looking at an html version of the doc and upon re reading it, it appears that the people doing the study show that IDCC holds 4 essential patents out of a pool 151 essential patents in 3GPP.
The paper is trying to identify the actual patents that are essential. At the time this paper was written, it appears as though IDCC had only claimed 11 patents as being essential to 3GPP.
However in 3GPP2, IDCC isn't listed at all.
This exercise doesn't seem like a fruitful way to objectively find the number or % of essential patents held by IDCC. They take a very narrow view of what it means to be essential.
I think what it comes down to is testing what you have in court or in the marketplace. You get what you can prove others will pay by agreement or forced by the court.
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