3 ms·
IIRC - It's less voice over 3G and more voice over 2G but done on whatever radio interface you have. A question of using pre-IMS voice call interface vs. using
by p_l 5y ago
IIRC - It's less voice over 3G and more voice over 2G but done on whatever radio interface you have. A question of using pre-IMS voice call interface vs. using IMS one (which was actually introduced with 3G, but first use for plain voice that most people have seen was WiFi Calling)
- username190 5y agoAT&T shut down their GSM 2G network in 2017 - the remaining circuit switched calls were going out over UMTS (3G) until the shutdown.
- p_l 5y agoThe radio interface used is 3G/4G, but it still used circuit switching instead of IMS (which uses GPRS channel - just like your 3G/4G/5G data - and SIP, iirc)