BGR exclusively reported last week that AT&T’s 4G LTE network has gone live in both Chicago and Atlanta, and at that time it was unclear if LTE was only available intermittently for testing or if the network had been soft-launched. Here we are a week later and the network is still live in both of these markets — and in the Dallas/Forth Worth area as well as in Houston, BGR has learned — so it is likely safe to say the latter is the case. More importantly in light of the fact that Labor Day is behind us and AT&T has been touting a summer launch for months, the carrier should make the launches official any day now. Considering AT&T’s network was recently ranked worst in the nation by J.D. Power, 4G LTE service can’t come soon enough. In the meantime, however, BGR was sent a video of AT&T’s new $700 Jetstream tablet running on the carrier’s LTE network in Chicago. A speed test shows that downloads peaked at over 22Mbps while upload speeds climbed above 6Mbps. AT&T’s previous-generation fourth-generation HSPA+ network is hardly lacking in the speed department, but it looks like LTE will top its performance and then some. A video showcasing a live test of AT&T’s 4G LTE speeds on the HTC Jetstream follows below.