Comment by BatteryMountain

Here's another one for you: today I found out that my dual-sim android phone has a single radio that is shared between the two sims. So when you are on a call, the 4G/5G doesn't work on the other sim, likewise, sometimes the the voice sim is unavailable while the other sim engaged with 4G/5G things... which is just stupid. Can't they just add two radios/chips (like many wifi AP's....)? So the whole setup on a consumer phone is actually quite unreliable because of reusing a single radio. I thought it was my buggy code, but nope, just the radio being shared and the mobile operator seeing the sim as offline. Crazy.