While you may not have even tasted vanilla EVDO yet, EVDO Revision A upgrades potentially offer wireless broadband speeds up to 3.1Mbps downstream and 1.8Mbps upstream. Well, almost; you should see real world downstream speeds from 800kbps to 1.5Mbps (depending on the carrier), with upstream speeds surpassing the 400kbps mark. The most important improvement brought by Revision A is latency: users should see latency drop from 150ms and up to 50ms.

EVDO Revision A network cards are already on the market. We touched on the release of the first Sprint Revision A card, the Novatel Wireless S720, back in August; since then we've seen the release of the Sierra Wireless AirCard 595 and the Pantech PX500 PC modem card. Novatel yesterday noted their full suite of EVDO hardware should be on the market during Q3, and Revision A phones should drop by the end of the year.

There's two major providers offering EVDO: Sprint and Verizon. While they're offering the same technology, there's some significant differences between the two.

Sprint claims that their EV-DO revision A upgrades will be available to around 40 million customers by the end of this year (their EVDO network aims to reach about 200 million customers in that same time-frame). The company hopes to have their wireless network fully upgraded by the end of 2007.

Verizon has offered no timetable for their Revision A upgrade plans. The company is facing a longer timeline than Sprint due to the fact that more than 50% of its network consists of 800mhz towers already feeling network strain (compared to Sprint's full array of 1900mhz towers).

Sprint allows users to connect their laptop cards to the network for $60-$80/month. The company also allows you to tether your phone via USB to your laptop with two plan options - $25/month for 40MB/month (with additional per KB charge), or a $40/month unlimited flat charge if you sign a two year contract. Sprint so far does not prohibit the sharing of bandwidth via the growing number of 3G Wi-Fi routers (previously discussed here).

Verizon also charges users $60-$80/month for laptop card access, but unlike Sprint, requires you also have a voice plan with the company. The company limits what phones you can use to tether, and charges users $45/month for "unlimited" data use, plus a $15/month tethering fee. Verizon prohibits the use of sharing bandwidth via 3G Wi-Fi routers. "When customers use unauthorized devices to share the service, they are in violation of their service agreements," says Verizon spokesperson Brenda Raney.

This is where you begin to see the major difference between the two companies: their terms of service and the actual definition of the word "unlimited". The increased capacity allowed by 1900mhz towers means Sprint (so far) isn't cracking down on users who suck down more than their fair share of bandwidth. In fact their website encourages streaming and other uses.

Verizon Wireless meanwhile, has been sending out warning letters to customers who gobble up more than 5 gigs a month. The company's TOS prohibit everything but e-mail and browsing, and company execs have hinted they may replace the "unlimited" tag with metered use.

There's no doubt that Sprint is beating Verizon to the punch when it comes to EVDO and EVDO Revision A. They're deploying the technology more quickly, with better prices, and fewer restrictions. Obviously that doesn't mean Verizon Wireless can't catch up down the road.

Those interested in seeing if they can get either, can find the Sprint coverage map and zip-code qualifier here, and Verizon's here (check BroadbandAccess in the menu). Also check out (and contribute to) our Sprint and Verizon Wireless speed tests.