Late Thursday, AT&T customers in New York City began noticing something strange about their wireless signal: It wasn’t just 3G anymore. That’s because AT&T has quietly begun to roll out its long-awaited 4G LTE network in parts of the Big Apple.

In other words, LTE has technically launched, but it may simply be for testing purposes, meaning the service may go down at any point. If you have one of AT&T’s LTE-enabled devices, which include the HTC Vivid, Samsung Galaxy S II “Skyrocket,” or the Samsung Galaxy Tab 8.9, and you live in New York City, today is the day to check out the new ultra-fast system, in case they decide to power down the system, now that all us pesky tech bloggers have let the cat out of the bag.
How fast, you ask? The Verge is reporting download speeds up to 41Mbps and upload speeds of around 15Mbps — far faster than the 5 or 6Mbps typically allowed on AT&T’s “4G” HSPA+ network.