NEW YORK CITY -- Sprint launched its Spark LTE upgrade in six new markets Tuesday, and Light Reading got a glimpse of how the network performs when loaded with users at the operator's event in Manhattan.

Sprint Spark is now available in Oakland, Calif.; Orlando, Fla.; West Palm Beach, Fla.; Waukegan, Ill; Newark, N.J.; and Tacoma, Wash. The total number of markets with Sprint Spark markets is now up to 24. (See Igniting the Future: Sprint Spark.)

Sprint was demonstrating how its Spark LTE upgrade performed on its 2.6GHz network streaming video data. The stream appeared steady and without jitters.

Figure 1: HTC GaGa!

Sprint's Antwan Piggott also ran speed tests for Light Reading using Ookla and Sensorly to test the performance on a busy network.

Figure 2: The Sensorly Test

The tests showed download speeds between 27.27 Mbit/s and 24.29 Mbit/s. Uploads clocked in at 9.29 Mbit/s.

Figure 3: The Ookla Test

The tests help to give some indication to how the Spark upgrade may behave when loaded up with users. "This is an area with many Sprint users," Piggott told us. "We've been seeing up to 74 Mbit/s down in unloaded areas."

FreedomPop CEO Stephen Stokols told Light Reading Monday that he was seeing "north of 60-70 megs down" on the Spark network in Los Angeles. (See FreedomPop Gets LTE iPhone, Free iOS App.)

The Spark speeds also remain a moving target right now as Sprint continues upgrades. Sprint promised Tuesday to eek more performance out of the LTE TDD radios that underpin the technology. (See Sprint: LTE TDD Speed Boost Coming Soon and Defining 4G: What the Heck Is LTE TDD?)

— Dan Jones, Mobile Editor, Light Reading