T-Mobile, which is upgrading much of the Northeastern United States with its 21 Mbps HSPA+ network is promoting the enhanced 3G data speeds as “4G speeds.” The company’s press release begins with “T-Mobile USA, Inc. announced today the continued expansion and customer availability of its HSPA+ super-fast mobile broadband network that delivers 4G speeds in the Northeastern U.S. and other major cities across the country.”

While the theoretical 21 Mbps download speeds of T-Mobile’s HSPA+ network is as fast as, or even faster, than nascent true 4G network technologies provided by Sprint via WiMax or Verizon Wireless–soon to be joined by AT&T–with LTE technology, the long-term potential of 4G networks at delivering even faster mobile broadband speeds is there and T-Mobile may not have that long to tout its “4G speed” network on evolving 3G technology.

HSPA+ is an evolution from HSPA, which is a 3G technology employed by GSM carriers, including AT&T and T-Mobile in the US. While T-Mobile is rapidly building out its 3G HSPA+ network, rivals such as AT&T and Verizon have committed to LTE for 4G and Sprint will be launching the HTC EVO 4G as the world’s first 4G Android smartphone on that carrier’s WiMax 4G network.

T-Mobile’s press release goes on to mention the Northeastern geographic area that will be blanketed by HSPA+.

As the company continues to aggressively broaden its HSPA+ network in the New York City metropolitan area, including New Jersey and Long Island, T-Mobile announces the further build-out and widespread availability – right now – of its super-fast network in adjoining regions, including Upstate New York (Albany, Buffalo, Rochester and Syracuse), Connecticut (Hartford, New Haven, Milford and Stamford) and Providence, R.I. Already live in Philadelphia, as well the Washington, D.C. suburbs, T-Mobile’s HSPA+ network will expand into Boston and Washington, D.C. in the coming weeks, further enhancing the Northeast corridor with 4G speeds.

(via: Engadget Mobile)