Is Google pondering an experimental HetNet?

The plot thickens around Google’s mysterious wireless plans. Consulting wireless engineer Steven Crowley this week spotted an FCC application from Google requesting permission to test an experimental radio network in and around its Mountain View campus.

What does Google have up its sleeve? Taken together with other Google wireless and broadband initiatives, this network could be a piece of a larger plan to build a future heterogeneous network, or HetNet, that combines both cellular and Wi-Fi technologies into a single extremely flexible and high-bandwidth system. HetNets will become the mobile carriers’ future network architectures, but there’s nothing precluding Google from deploying one, as well, using all of the Wi-Fi, small cell and unlicensed spectrum at its disposal.

Google’s small cell experiment

Though Google made portions of the application confidential so they’re not viewable by the public, Crowley was able to glean some interesting details from the document, which he then posted in his blog.

A Ruckus Wireless Wi-Fi hotspot/small cell

Essentially, Google wants to build and operate over two years a very dense network of 50 low-power small cells in both indoor and outdoor locations. The total breadth of the network would only be two miles so this would be quite a high-capacity concentration of cells indeed. It would use the same 2.5 GHz spectrum currently used by Clearwire for WiMAX and its forthcoming LTE network, but Google did not reveal the specific radio technology it would use, nor did it reveal the manufacturer of its base stations.

This isn’t Google’s first request to the FCC for to test a new wireless technology. Last February Google filed an application with the FCC to experiment with a new residential gateway that used advanced Wi-Fi and Bluetooth technologies to redistribute Google Fiber’s high-bandwidth connection. My colleague Stacey Higginbotham wrote that Google could be eyeing longer-range gigabit-Wi-Fi as a means of blanketing towns and cities with untethered broadband.

In addition, Google is a big cheerleader for the unlicensed TV white spaces, which would expand the free-to-access model of Wi-Fi to the wider mobile network. It’s also a backer of the FCC’s proposal to designate 3.5 GHz a shared band over which any company could deploy small high-capacity cells. Google wants to test its new small network over licensed frequencies, but that doesn’t mean it couldn’t shift over to the shared small cell band when it becomes available.

Google Mobile?

Despite all of the rumors about Google teaming up with Dish Network or T-Mobile, I have serious doubts Google wants to become a full-fledged license-owning mobile operator. But the more details emerge about the Google’s wireless experiments, the more I suspect that Google plans to get into the mobile business – or at least the mobile broadband business – in a very non-traditional way.

Instead of building towers, buying nationwide 4G licenses, and offering voice and SMS plans, Google could build tightly integrated, multi-technology, small cell mobile data networks around the country. Starting with Google Fiber cities, it could use its install base of residential and business connections to deploy a shared gigabit Wi-Fi network that any other Google Fiber customer could access (similar to the residential hotspot approach Free Mobile uses in France).

Second, Google could build a network of indoor and outdoor LTE small cells, either tapping into the new shared 3.5 GHz band or by leasing airwaves from a company like Clearwire, and those cells could be backhauled again with Google Fiber links. In rural or less densely populated areas it could extend its networks range by using white spaces. All of those parts wouldn’t exist as separate networks. HetNet would glue them all together, allowing customers to seamless move between Wi-Fi connections and cellular links and in many cases access both radio technologies simultaneously.

“The most recent Google application might be part of a larger plan leading to HetNet architectures in which, say, licensed and unlicensed wireless networks would be combined,” Crowley said when I asked him about the possibility. “Backhaul for such networks is technology agnostic but Google Fiber could be made to handle it.” Crowley, however, was quick to point out that there is nothing in Google’s numerous FCC applications that indicate it has HetNet plans in the works.

If Google were to take the HetNet approach to mobile broadband, it would have to ask itself a key question. Would it want to focus solely on dense urban zones – where most mobile data user congregate – or would it want to fill in all the gaps in between? If it’s the latter case, then Google would have to start playing the mobile operator’s game. You simply can’t provide 4G coverage on a freeway using small cells and Wi-Fi.

Google wouldn’t necessarily have to buy another operator or build its own big-tower macro network from scratch though. It could become a mobile virtual network operator (MVNO) leasing capacity off of a T-Mobile or a Sprint’s network in areas where its HetNet couldn’t reach. As I’ve written before, the carriers are now much more open to the idea of selling network capacity to potential competitors. But then again, the carriers have never dealt with an MVNO that would be as powerful and threatening as Google.