Middleware certainly seems plausible; see also the state of x86 UEFI firmware, which is basically just one company (AMI) selling customized firmware outside of

Middleware certainly seems plausible; see also the state of x86 UEFI firmware, which is basically just one company (AMI) selling customized firmware outside of the FOSS coreboot/libreboot world. With how complicated most cellular standards are, I imagine a lot of modem firmware is just one company we've never heard of selling a basic implementation that gets customized for each modem vendor. Keeping the implementation secret as a condition of licensing the patent is not entirely unimaginable. It would be, however, very, very stupid (if you aren't outright evil), and not provide any extra licensing rents to the SEP holders. In the video world they don't do this; because everyone expects that anyone actually shipping a codec is going to pay[0]. But then again this is also cellular firmware; implementing standards owned by Qualcomm. And Qualcomm loves pushing the boundaries of how anticompetitive you can be with legal monopolies before actually violating competition law. They're the ones that saddled the US with "CDMA" "standards"[1] that put half of America's carriers on incompatible networks with phones you couldn't migrate to other networks. (Even other CDMA networks!) If Qualcomm had their way, they'd own LTE and 5G lock, stock, and barrel with the only modems you can buy being buried in a Qualcomm Snapdragon SoC. [0] That's not to say that video SEP owners are particularly happy right now. The head of MPEG insists he was sacked for, among other things, complaining about MPEG's inability to standardize a royalty-free codec under ISO's patent disclosure rules. [1] Including a competing standards body to 3GPP called, I shit you not, 3GPP2.