Sprint is ahead in the race to roll out so-called 3.5G cellular broadband networks that provide faster upload speeds when connecting to the Internet.

On Tuesday, Sprint announced it was rolling out service in three more markets in South Florida, Portland, Ore., and Puerto Rico. It has already rolled out in Seattle and 21 other markets.

Almost as a comeback, today Verizon Wireless announced initial plans for rolling out its 3.5G network, also called EV-DO Rev A. It said in the service will be in the Boston area, the Richmond, Va., area, Chicago, Salt Lake City and in other cities in Utah, and throughout Verizon's footprint in Florida.

In general, Sprint said consumers can expect average download speeds of 450 to 800 kilobits per second (Kbps), with peak rates up to 3.1 megabits per second (Mbps). Upload speeds span between 300 and 400 Kbps, with peaks up to 1.8 Mbps.

I've had a lot of practice using both networks from both carriers. On a regular basis, I use Verizon Wireless 3G network -- something The Seattle Times pays for -- and am currently testing Sprint's 3.5G network through a loaner.

For the most part, when surfing the Internet and writing stories, I can't tell a difference between the two. However, there's a stark difference when sending data up, something I rarely do, but do notice the Sprint 3.5G service (vs. the Verizon 3G) is faster when uploading images I snap for the blog while traveling.