Google wades into the murky waters of 5G with Alpental buy

Google(s goog) has acquired Alpental Technologies, a Seattle-area startup looking to build wireless technologies that may some day become part of our 5G networks. GeekWire first reported on the deal on Thursday, and Google confirmed it with me Friday, though it didn’t offer up any additional details.

The news renewed speculation that Google will dive into mobile networking, challenging carriers on their own turf. That’s definitely a possibility, but we shouldn’t read too much into this particular acquisition. As I’ve written before, 5G is a much different animal than 4G, which can pretty much be summed up as a single radio technology: LTE.

5G hasn’t even been defined by the mobile industry yet, but the companies and researchers that are pursuing those standards agree that 5G isn’t going to be a single network technology. Rather, it’s going to be a mishmash of different radios, new bands of spectrum and even the melding of different kinds of networks using licensed and unlicensed airwaves to reach users. Basically, the industry is using every tool it can find to cram more capacity into future networks.

Photo by Tomasz Wyszoamirski/Thinkstock

Photo by Tomasz Wyszoamirski/Thinkstock

The Wall Street Journal’s Digits blog dug up an FCC filing that shows Alpental is specifically working on technologies in the 60 GHz millimeter wave band, which today are pretty useless for any kind of wide-area networking. The emerging WiGig standard uses 60 GHz, but it’s designed to connect devices in the same room with multi-gigabit connections, not to connect phones to towers. If you want millimeter waves to carry any distance you need a big transmitter pointing a very powerful beam at a big antenna.

But a lot of 5G proposals call for making those ultra-high-band frequencies friendlier for mobile networking. By using technologies that could steer signals toward devices and a boatload of antennas, mobile industry engineers believe they can create extremely high-capacity links that transmit at much lower power.

Whether one of these millimeter wave connections would provide that final hop to your phone remains to be seen. The phone or tablet’s small size isn’t very conducive to complex antenna designs, and according to the network engineers I’ve talked to, these technologies are really more for fixed or nomadic connectivity, not for true mobility. In other words, you can pick a device up, place it somewhere else and re-establish a connection, but if you try to walk (or drive) around with it, the network can’t follow.

Consequently, networking companies are looking at millimeter waves as a network middleman. They could be used to provide the backhaul connection from a tower to dense clusters small cells or Wi-Fi access points scattered throughout the network.

Small cells would add surgical capacity to the most high demand areas of the network (source: Gigaom / Rani Molla)

Small cells would add surgical capacity to the most high demand areas of the network (source: Gigaom / Rani Molla)

In such a scenario your phone would still be using the same LTE and Wi-Fi radios it always had, but 60 GHz networks could load up the overall network with tremendous amounts of capacity they simply can’t support today.

Google is already heavily invested in providing broadband access (through fiber, wireless and even balloon-based means) and it looks set to get into the Wi-Fi hotspot business. Buying Alpental doesn’t necessarily mean it wants to become a mobile carrier or network equipment maker. It may just be looking for another alternative to broadband connectivity.