In March, Apple unveiled the new iPad, the first iDevice that connected to a 4G/LTE network. With the next generation iPhone expected to arrive sometime this year (a handset that will almost certainly also offer 4G capabilities), it’s important to know which of the top U.S. carriers provides the best 4G experience. Unfortunately, finding this out isn’t always easy, as a new report by All Things Digital suggests.

In the U.S., the two largest wireless providers, AT&T and Verizon Wireless, are constantly telling us their 4G/LTE network is fastest. Who’s telling the truth? That depends on who’s doing the testing.

Both say they are the best

Recently, AT&T began pushing a new PCWorld study that says its LTE network is vastly superior to the one being offered from Verizon.

Says PCWorld senior editor Mark Sullivan:

“In our tests, AT&T’s new LTE network pumped out the fastest speeds of any 4G provider.”

AT&T Coverage Map

AT&T Coverage Map

Verizon Wireless, for their part, is pointing to a RootMetrics study that concludes their network is the best performing in “real-world” tests.

According to RootMetrics president Bill Moore:

“AT&T’s LTE might be faster, but our overall experience with AT&T was still slower than what we found with Verizon.”

Verizon's Coverage Map

Verizon's Coverage Map

Sprint, meanwhile, is launching their own LTE network very soon. By contrast, T-Mobile is aiming to launch an LTE network in 2013.

A Draw? Not Necessarily

In reality, the company that offers the best LTE experience is the one that provides the best service where you live.

On this, Verizon’s LTE service stands out since it is now available in two-thirds of the U.S. AT&T’s 4G network, by contrast, is much smaller, but growing.

Our advice: First, determine where you’ll be needing 4G service most (near your home, on the road, etc.) In addition, find out which provider offers the best 3G service. After all, 4G isn’t available everywhere, so knowing where the slower connection is available is also important.

Where are you finding the speediest 4G/LTE network?