Haven't tried it myself, but this official-seeming website suggests that you can schedule a test call ahead of time with your local 911 call center.

https://www.911.gov/calling-911/frequently-asked-questions/#...

You can schedule a 911 test call. "Test calls can be scheduled by contacting your local 911 call center via its non-emergency phone number." [0] More info here:[1]

[0] https://www.911.gov/calling-911/frequently-asked-questions/ [1] https://www.nasna911.org/home

I'm pretty sure Google can buy a femtocell to simulate local mobile network of their own.

Phone makers (and even their supply chain partners) operate their own in-building cell networks with carrier-type hardware, and extensive debugging and observability, including simulation of multiple towers and location.

It wouldn’t get you 100% E2{ for 911 testing, but it does let you develop and test the stack extensively before taking it to the real world and scheduled testing coordinated with 911 call centers.