With Apple providing dual SIM support on the latest iPhones in some regions and most Android phones offering the same, it's no surprise to see Google introducing actual dual SIM support on the upcoming Pixel 4. But later in the year, the company will likely launch the new Pixel 4 line sometime around October.
That is different than the Dual SIM, Dual Standby system found in the 2018 iPhone models.
While the Pixel 2 and the Pixel 3 can technically support two SIMs through eSIM technology, it's not the more advanced version of the tech available in many other handsets, including the latest iPhones. An eSIM, or embedded SIM, is a chip placed inside the phone that takes the place of a SIM card. ESIM is only used by a few carriers around the world, including Sprint in the U.S., but it can act as a second SIM alongside the hardware SIM when activated.
It's being said that the Pixel 4 will get Dual SIM, Dual Active (DSDA) functionality. Lastly, DSDA means that both SIMs can be used for calls, texts, and data at the same time. You'll have to switch between the two networks to receive calls and messages from the respective network. You can make and receive calls and messages on both networks without switching as long as the SIM isn't being used for that same goal. You can not use Dual SIM, Dual Standby to be on two calls at the same time, or have two text messages going on simultaneously. Because it requires two radios, it isn't very common.
Based on the Commit found on the AOSP page (see image at the bottom of this article), a Google employee says that Android Q will support Dual SIM, Dual Standby or even Dual SIM, Dual Active if the device and the carrier support it as well. Just as interesting, however, is the note that the Pixel 3 does have that as well but is limited to internal testing. Hopefully, Google will decide to flip the switch for the Pixel 3 when it gets Android Q.