Clearwire plans LTE-Advanced, if it can afford it
Insists it will build TD-LTE and then LTE+ on its own, not as part of Sprint's Network Vision architecture
Published: 5 August, 2011
At last, some clarity on the murky 4G plans of Clearwire/Sprint. The former has finally confirmed what has been long expected, that it will build TD-LTE alongside its existing WiMAX network, and aims to trial LTE-Advanced at an early stage. It has plentiful spectrum to support two networks, at least for a while - but not plentiful cash, so presumably the grand plan is subject to raising more funds, or merging its operations into Sprint's multi-technology Network Vision program.
Clearwire has been trialling TD-LTE and WiMAX coexistence for over a year, with incumbent supplier Samsung and also Huawei, and has also done some early LTE-Advanced tests. Many believe it will move its LTE network to Sprint's common infrastructure to save costs, which would bring its 2.5GHz spectrum into the mix alongside Sprint's own bands and those of network sharing partner LightSquared. That could deprive Huawei of one of its few major US infrastructure deals, since Samsung is already a supplier to Network Vision - just as the LightSquared deal has reduced its contract with Nokia Siemens to just the core network.
For now, though, Clearwire is insisting that it will build TD-LTE itself, without Network Vision. Indeed, on the quarterly results call, Clearwire's interim CEO John Stanton said that the firm had investigated hosting its future networks on Vision, but had decided it would be cheaper to overlay LTE on its own WiMAX infrastructure. "It's so inexpensive to add another technology to our equipment, it represents a significant economic advantage," Stanton said. "Sprint is effectively buying new boxes. We're using our existing boxes." He said it would cost about $600m to compete the overlay in its most trafficked markets, and take about 12 months from the start of the process. He did not specify how many markets would be included in that sum.
Using LTE-Advanced aggregation techniques, the operator could deploy carriers 5-10 times the size of the 10MHz WiMAX carriers it uses today, reaching speeds of 120Mbps or so.
WiMAX and TD-LTE are technologically quite close, and suppliers like Samsung and Huawei already have infrastructure and devices that support both standards. However, the decision would seem to distance Clearwire further from its main customer and investor - even though, if the relationship breaks down completely, it will not have enough funds from its other resellers and stakeholders to carry out its plan, however cheap. Clearwire added 1.54m net new WiMAX subscribers in Q2, but only 39,000 were under its own brand and nearly all the wholesale customers come via Sprint, which activated 1.7m WiMAX devices in the quarter.