I recently made a Facebook post about the pager network. I pointed out that the Flex and reFlex protocols used by the pager network will still be running long after 2G, 3G and 4G are gone. (See below for the sunset schedule.) It's weird that this old 90's tech will still be in operation after several generations of the cellular network are gone. (See Old School: Pager Code for look-a-like codes and Beep Codes list for common standard 3 digit codes.)
What's weirder than that? Telegraph networks are still operating. That means a system originally started in 1840's will outlast several generations of the cellular network! Wow!
Now, I must admit that I recently discovered telegrams are still a thing in the 21st Century from a Youtube video.
So, you know what I did? I sent a xmas message via telegram to my friend. And, I learned a few things about the process along the way. Despite operating completely through a website (as all things must), it appears the process still has manual nuances. For example, any type of special instructions must be typed into the either the address field or other special field, in specific ways. There's no website checkboxes for many types of instructions, such as stating a delivery date or specifying to only deliver to the addressee.
2G was already dropped most major services some time ago, but still hangs on with T-Mobile. They'll be shutting it down in 2023.3G is actually getting shut down before 2G, at the end of 2021.4G is also getting shut down before 4G, sometime during 2022.