New devices allow for mobile wireless broadband

T-Mobile USA said it will upgrade its 3G network to double the possible download speeds in two-thirds of its coverage area. It started calling the network “4G” in ads last fall. It, too, revealed two tablets for its network, to launch later this year.

Sprint and Clearwire have chosen a slightly different route to 4G wireless service. They’ve picked a 4G technology called WiMax that was ready before Long Term Evolution, or LTE, which Verizon is using.

Now, however, WiMax looks set to be a niche technology, while the rest of the industry adopts LTE. That will hamper Sprint’s efforts to get competitive devices for the network. Still, it was able to launch its first 4G phone last summer, ahead of the competition.

On Jn. 5, Sprint announced it would be the first to carry a 4G tablet computer from Research In Motion Ltd., the maker of the BlackBerry, some time this summer.

The most distinctive feature of 4G wireless technologies like LTE and WiMax is that they’re designed to carry data rather than phone calls. That makes them more efficient at serving today’s smart phones, tablets, and other gadgets that need data access on the go. It also makes the networks cheaper to build out and manage.

They’re faster than today’s 3G networks, though not by much, which makes T-Mobile and AT&T feel justified in calling their upgraded 3G networks “4G.” After all, they say, speed is what really matters to users.

Aside from the bump in speed, the main reason the LTE buildouts of Verizon Wireless and AT&T are significant is that they add fresh spectrum to the nation’s wireless networks. That means more capacity for the growing number of mobile gadgets.