I don't think that you can directly compare Qualcomm to InterDigital. I own both and they're both an important part of my portfolio. With that being said, Qualcomm is a giant compared to IDCC and Qualcomm Ventures makes very smart strategic investments in that country. These chipsets make Chinese companies like Coolpad, Xiaomi, etc. possible:
<<JAN 17, 2016 SAN DIEGO AND BEIJING
Qualcomm and Guizhou Province Sign Strategic Cooperation Agreement and Form Joint Venture to Design and Sell World-Class Server Chipsets in China>>
Qcom has charged licensees the same rate since the inception of it's licensing program. Nobody likes paying royalty; but, if you are confident that your competitors are paying the same, you can sleep at better night.