Forget Ethernet, researchers want data centers to go wireless

You know those cabling contests that try to get systems administrators to show off their racks? If this article from the MIT Technology Review is right, those may become a distant memory as researchers from the University of California, Santa Barbara, Intel and IBM (s ibm) have shown how they can send data between servers without those pesky cables using 60 GHz wireless and bouncing those radio signals off the ceiling.

That means rapid data transfers up of to 500 Gigabits per second (current Ethernet cables in data centers are generally 1, 10 or maybe 40 gigabits per second) and less mess with physical cables. Of course, every switch at the top of a rack would have to get a radio card slotted into it, and there’s also the matter of putting reflective panels on the ceiling for the wireless signals to bounce off of. The top of the servers would also need some kind of signal-absorbing surface so the signals don’t continually bounce around the data center. From the article:

To maximize the bandwidth and reduce interference between signals, it needs to be focused into narrow beams that require a direct line of sight between endpoints. “Any obstacle larger than 2.5 millimeters can block the signal,” she says.

One way to prevent the antennas from blocking each other would be to allow them to communicate only with their immediate neighbors, creating a type of mesh network. But that would further complicate efforts to route the data to the appropriate destinations, says Zheng. Bouncing the beams off the ceiling directly to their targets not only ensures direct point-to-point communication between antennas but also reduces the chances that any two beams will cross and cause interference. “That’s very important when you have a high density of signals,” she says.

While it sounds kind of out there, the researchers hope to build a prototype data center to try the idea out. Mark Thiele, the EVP of data center technology at Switch Communications’ SuperNAP data center, says the research is worth following as low-latency networking inside the data center can be a bottleneck today for applications that range from financial trading to trying to move gigantic data sets around.

The choice of 60 GHz for the data center is possibly inspired. Intel (s intc) is one of several chip firms pushing 60GHz for consumer use, under the WiGig brand. This means the chips would be cheap. Additionally at 60 Ghz, signals deteriorate rapidly, which sucks if you want to transmit data over long distances, but is a boon if you are worried about someone standing outside the data center trying to eavesdrop on the data you are transmitting. However, using wireless, especially wireless with somewhat persnickety propagation limits (can’t travel far, requires line-of-sight between endpoints), means that data center technologists will suddenly have to learn a different type of network engineering, skills more familiar to their brethren setting up base stations in the cellular world.