I admit I only briefly looked at each patent but even looking a second time, I can not find anything more specific basically the devices share clock information

I admit I only briefly looked at each patent but even looking a second time, I can not find anything more specific basically the devices share clock information and calculate the difference between their clocks. How is this different than syncronizing transactions between database servers or how GPS works? I found a GPL license multi-room/device audio player that discussed this very lawsuit last year [1]. The developer raises the same point than anything like this will involve something resembling clock syncronization. Looking through the lawsuit itself, about 90% of it is just comparing the end result of Sonos' & Google's products in that both let you add/group speakers, adjust volume and playback of the group, etc. I cannot find any claim that Google's implementation is a copy of Sonos'. It seems to try to sugest that is the case by bringing up that prior to Google's devices, Google had worked with Sonos and had access to details of their implementation. [1] https://github.com/badaix/snapcast/issues/642 https://github.com/badaix/snapcast/issues/642