T-Mobile’s HSPA+: It may not be 4G, but it's really fast

You can debate all you want whether T-Mobile (NYSE:DT) is offering a true 4G service, but its high-speed packet access plus (HSPA+) network is quickly emerging as one of the fastest in the country, even if the most T-Mobile devices can’t yet fully take advantage of HSPA+’s full connection speeds.

Wireless testing firm Root Metrics found that T-Mobile smartphone average upload and download speeds have improved tremendously over the last year as T-Mobile has rolled out its HSPA+ upgrade. Though only a handful of T-Mobile phones actually have the silicon to take advantage of HSPA+’s 5 Mb/s-plus speeds, the addition of fiber backhaul and increased network capacity appear to be benefiting all mobile broadband users no matter what device they own.

In a sample of six major markets—Chicago, Dallas, Los Angeles, New York, Oakland and Orange County, Cal.—T-Mobile clocked average download speeds higher than 400 kb/s (in Orange Country, higher than 500 kb/s) and average upload speeds higher than 300 kb/s, exceeding all other operators’ network performance in every market except Oakland (where AT&T was just barely the leader), according to testing done by Root between August and September of 2010. When Root performed similar testing last year, T-Mobile was often third or last among the major operators recording sub-200-kb/s speeds in many cases.

What’s interesting to note is none of the connections tested were true HSPA+ connections since Root does all of its testing via smartphones, using its own crowd-sourcing app to perform millions of measurements each month.

-Mobile launched its first HSPA+ smartphone, the G2, in October, followed quickly by the myTouch 4G. HTC is terming them both 4G phones because they can access HSPA+’s theoretical speeds of 21 Mb/s, though the operator claims real-world speeds between 5 Mb/s and 8 Mb/s are more realistic.
So why did T-Mobile’s smartphones test so well even before its new-fangled phones were on the market. The answer likely lies with the network upgrade, not with the devices. As T-Mobile has pointed out, the HSPA+ network upgrade has been in place practically since it started building its 3G network.

What was missing was a fat backhaul pipe to each cellsite that could support HSPA+’s enormous capacities. As T-Mobile installed fiber connections to its cellsites in various markets it officially ‘turned on’ HSPA+ in those cities. That resulted in two things: 1) true HSPA+ devices like its USB modems could take advantage of that capacity, allowing them to get their downloading task done faster, thus clearing network capacity for slower ‘3G’ smartphones, and 2) the fiber connections eliminated the bottleneck in the backhaul allowing more devices to consume more data on every cell site.

Root’s tests over the next few months could become very telling as more HSPA+ smartphones are activated on the network and those subscribers start downloading the Root crowd-sourcing app.

T-Mobile won’t necessarily come out on top though. Root said it has only begun tracking smartphone data from Sprint’s 4G WiMax network and those results haven’t yet been formally incorporated into its data. So far Sprint (NYSE:S) has performed rather poorly compared to the other Top 3 in Root’s tests, but that’s because they’re only taking the EV-DO network into account. Once the results from millions of EVO 4G and Epic 4G start factoring in, Sprint could easily jump to the lead.