Mobile phone patents are dominated by large companies like Qualcomm, Ericsson, and Samsung. Taiwan and China have become hubs for mobile phone assembly, with fabless IC companies designing chips and manufacturers assembling phones. However, it is unclear if royalties are paid for underlying patents. The document discusses exploring open hardware approaches for mass-produced mobile phones, like Phonebloks and Project Ara, noting hurdles around basic components like baseband chips being closed. It outlines potential revenue streams for open hardware phones beyond direct sales.