T-Mobile to double 3G network speeds in 2011

T-Mobile USA (NYSE:DT) will deploy multi-carrier high-speed packet access plus (HSPA+) in 2011, effectively doubling the speeds available to its customers, though not necessarily increasing its overall network capacity. The technology effectively stacks HSPA carriers on top of one another allowing T-Mobile to deliver downlink speeds theoretically in the 42 Mb/s and real world speeds slightly higher than double its current 5 Mb/s to 8 Mb/s benchmarks.

In an interview at 4G World in Chicago, T-Mobile Senior Director of Engineering and Operations Mark McDiarmid said that while the operator is still in the process of completing its nationwide upgrade to HSPA+, it is fast at work on its next network upgrade and plans to begin rolling out multicarrier networks and devices sometime in 2011. “We will go really big on multi-carrier in 2011,” McDiarmid said. “The process is already well in hand. The upgrades in many places are well in hand.”

Multicarrier is a carrier-stacking technology, which doesn’t increase the networks overall capacity but allows an operator to double up on spectrum used on its network. T-Mobile’s current HSPA+ network can support up to 21 Mb/s over a 5 MHz downlink channel, but with multi-carrier T-Mobile can merge two 5 MHz channels into a super-carrier of sorts, allowing it to serve up their combined throughput to customers. Though the upgrade won’t increase overall network capacity, multi-carrier does offer some distinct benefits that will improve the overall quality of experience to customers and operational efficiencies for T-Mobile, McDiarmid said.

The most obvious benefit will be faster speeds to customers. HSPA+ already provides speeds in excess of what customers typically get on 4G services like Clearwire’s (NASDAQ:CLWR) WiMax network. Multi-carrier will allow T-Mobile to offer connections to the customer comparable to newer long-term evolution (LTE) networks emerging this year and next.

The more powerful transmission from the stacked channels will also improve network performance at cell edges, a problem especially acute for HSPA+ networks, where average speeds drop considerably the further away the user is from the tower. The fatter pipes of multi-carrier also increase overall network capacity available to all users through a principle called queuing theory. With more capacity available over a single channel, individual users get on the network and perform their transactions faster, freeing up more capacity for more users.

Ultimately though, HSPA+ multi-carrier will be a more inefficient technology than LTE or WiMax. HSPA+ may be able to deliver 4G speeds to individual consumers, but 4G networks will be able to deliver more capacity per hertz of spectrum and more capacity per operational dollar than any HSPA network--at least theoretically. McDiarmid pointed out that 4G networks, particularly LTE, are newer technologies that still haven’t proved their merit in real world. Meanwhile HSPA technologies have matured since its launch in 2004—the kinks have been worked out, the equipment costs have fallen, and the device ecosystem fully developed, McDiarmid said. While LTE may have plenty of operational advantages on paper, HSPA technologies will be able to keep pace until LTE can fully live up to its promise, McDiarmid said.

“When you peel back the layers on the newer technologies, you see some inherent limitations,” he said. “We’ve detected a slight misperception in the market about HSPA. HSPA+ has a very rich development path into the future. It’s also one of the most supported technologies globally. If you look outside of America, it is the dominant mobile broadband technology.”

MacDiarmid said he could provide no timeline on when multicarrier would be available, though he added that the obstacles are more market-related than technological. The software upgrades from base station vendors Nokia Siemens Networks (NYSE:NOK, NYSE:SI) and Ericsson (NASDAQ:ERIC) are available and in some cases already installed, he said. T-Mobile is working with device vendors to produce multi-carrier devices for its networks, but as in the case with any new HSPA iteration, it takes time for the device ecosystem to catch up with network capabilities. Once T-Mobile completes its nationwide backhaul upgrade to support its HSPA+ launch, all of the primary hardware will be in place. Once the first devices emerge next year, T-Mobile will be ready for launch, McDiarmid concluded.

While T-Mobile is only talking stacking two carriers today, it could theoretically stack multiple carriers to create massive pipes exceeding 80 Mb/s of capacity in markets where it holds plenty of advanced wireless services spectrum. In San Francisco, for instance, T-Mobile has 50 MHz. It could feasibly create a 25 MHz super-carrier, supporting theoretical speeds over 100 Mb/s, if it chose.

As for moving further down the HSPA migration path, McDiarmid said T-Mobile had made no decisions yet. The next step would be for T-Mobile to deploy multiple input-multiple output (MIMO) smart antenna technology, which would theoretically double the capacity available over same MHz spectrum. But McDiarmid said that MIMO is much more expensive upgrade, requiring much more new equipment, while multi-carrier is primarily a software upgrade.