Pixel 4 (XL): Dual SIM support could get better
of David Haydl 
on February 11, 2019, 10:00 p.m. | Write a comment
Two SIM cards could only be used to a limited extent with the previously released Pixel devices. That could change with the Pixel 4 (XL), which is likely to appear in autumn.
Supported the Pixel 2, the Pixel 2 XL, the Pixel 3 and the Pixel 3 XL two SIM cards, but only to a limited extent. One SIM card is a physical nano SIM and the other is an eSIM. But the whole thing has one major disadvantage. Only one card is active at a time. This is called Dual SIM Single Standby, or DSSS for short.
The solution: DSDS or DSDA
Google is supposed to do better with the Pixel 4 and Pixel 4 XL. This can be seen from the AOSP, the Android Open Source Project. According to it, the upcoming Pixel smartphones support DSDS or DSDA. DSDS stands for Dual SIM Dual Standby and DSDA is the abbreviation for Dual SIM Dual Active. In both modes, all cards can be used as needed. However, DSDA requires two modems (which are rare today), which means that DSDS will most likely be used in the upcoming Google phones.
Source: XDA-Developers
Street: mobile flip