This week, scientists from IBM Research announced the creation of a chipset solution which makes use of unlicensed spectrum from 57-64 GHz. The chipset, which promises speeds of well over one gigabit per second (Gbps), is designed to work within the evolving millimeter-wave or “mmWave” 802.15.3c specification for wireless personal area networks (WPAN). 802.15.3c itself aims to deliver data rates of 2 to 3 Gbps or more.
Brian Gaucher, Research Manager at IBM Research, says 60 GHz is extremely attractive for high-bandwidth multimedia applications. “It’s free, unlicensed and available around the world – and there’s 7 GHz of space, which just means speed for us,” he says. “To make silicon actually work there, and do it at a low cost, was a perfect challenge.”
That’s not to say that the researchers began the project with anything resembling optimism. “We put it into silicon, and the stuff actually works!” Gaucher says. “I say that because none of us really thought you could do it.”
Gaucher says a key focus of the effort was to ensure that the result was a manufacturable chipset. “You’ve got to give it to a customer, a vendor who can put it into their system,” he says. “So we actually spent time looking at antennas and packaging and wrapped it all together – so it’s all on a single chip, with virtually no off-chip components except bias resistors and capacitors.”
The result, Gaucher says, is a solution that provides much more functionality than the comparatively limited bandwidth of Bluetooth, or the comparatively limited power and speed of ultrawideband. “We have the bandwidth available to do really high speeds, and to push into the gigabit-per-second space,” he says. “We’ve got room for growth in the future.”
The high bandwidth of 802.15.3c makes it particularly appropriate for video applications – such as eliminating the need to connect HDMI cables to a plasma television, which requires 1.485 Gbps. “You pay $5,000 for a plasma TV, throw it up on the wall, and then you’ve got to drag these huge HDMI cables around the house,” Gaucher says. “People don’t want to do that, so consumer electronics manufacturers are looking at putting these types of solutions in their systems.”
Still, Gaucher admits there are some issues remaining – this week’s announcement, he says, is just the beginning. “Where does the high speed signal actually come from that can drive a radio at these speeds in a cost-effective, low-power way?” he asks. “The digital signal processing, the MAC, the protocol, all those are things that underlie the radio itself – where do those come from? We’ve got this radio ready to go in the lab, and then you’ve got to hook a baseband to it to make it do what it is you want to do. I think there’s tremendous IP available for whoever wants to invent in that space: how to do that for reasonably low power and low cost is probably one of the outstanding challenges there.”
To encourage that kind of innovation, Gaucher says, IBM Research is active in the 802.15.3c standards process, developing what he calls “the next personal area network standard.” With a real need for multi-gigabit-per-second solutions for multimedia applications, he says, “This is getting the most traction that I’ve seen in the standards groups that I’ve been involved in.”