but the 4G field has been relatively barren. Turns out, there’s an open source suite called srsRAN that lets you use an SDR for setting up an LTE network, and recently, we’ve found a blog post ...

called VoLTE (voice-over-LTE). Even so, a particular phone can choose to use a 4G modem, yet still use 3G-style phone connections. Until the 3G network is shutdown, that is. This is the crux of ...