Big Power in a Small Package
As west coast utilities struggle to keep up with fast-growing demand for electricity, a Milpitas, Calif., start-up claims that a transceiver chip technology breakthrough may cut the power needed to run high-speed network equipment by two-thirds.
The leaner chips manufactured by BitBlitz Communications could slash the amount of energy consumed by Internet traffic and save carriers a chunk of money in the process.
A controversial study by the Green Earth Society claims that the Internet consumes as much as 8 percent of all electric power today, and that the entire digital economy will gobble up 50 percent by 2020.
But Amory Lovins, who as president of the Rocky Mountain Institute wages war on wasteful energy consumption, says the Internet has saved more energy and electricity than it has ever consumed and will continue to do so.
"Ninety-nine percent of power failures come from problems in the grid, not from inadequate generation, and 95 percent of grid failures are in distribution," says Lovins, who blames rolling brownouts reported in December 2000 in California on several Canadian provinces and Western states "doing almost nothing to use electricity more efficiently."
Making chips smaller and speedier so that they provide more power while using less electricity is the goal of company engineers and the scientists from labs, start-ups, fabrication plants and universities that team with them.
For example, IBM expects to begin delivering this summer 0.13-micron chips that it says will dramatically reduce the wattage needed to perform a task.
"In the race to make faster chips for the Internet, every small gain in speed has been accompanied by huge increases in power consumption," BitBlitz Chief Executive Bin Wu says. "We have developed an important low-power semiconductor technology that will help the Internet run faster."
Leo Wong, BitBlitzs director of strategic marketing, says his companys "technology breakthrough is in our clock and data recovery unit."
All data that flows over the Internet is moved by transceiver chips that power switches and routers. One of the most important functions of transceiver chips is to decipher timing and data information embedded in high-speed serial links. This circuit, known as the clock and data recovery unit, performs the equivalent of finding a needle in a haystack billions of times per second. As network processors receive the timing and data information from the transceiver, they route packets to appropriate destinations.
Traditionally, chipmakers have used an analog approach to accelerate the reading of the ones and zeroes. That approach is power-hungry, expensive and incapable of integrating logic or of putting multiple channels on the same chip.
Another approach is digital, which can integrate logic and multiple channels on the same chip and makes it possible to divide traffic onto multiple wavelengths. But that approach cant increase in speed.
BitBlitz takes a hybrid approach, known as large amplitude differential logic, which combines the speed advantages of analog and the integration advantages of digital. Most importantly, the chip is manufactured using the ordinary complementary metal oxide semiconductor process. By making CMOS chips run as fast as the more exotic gallium arsenide and bipolar chips, BitBlitz ignites systems that consume less power, achieve more aggregate bandwidth and take up less rack space.
"It allows us to grow in both speed and channel and integrate logic and do it at extremely low power," Wong says.
The resulting transceiver uses one-third to one-fifth of the typical wattage. And that means several chips can operate in parallel without needing to consume even more power to cool the electronics. That can make Dense Wavelength Division Multiplexing an ingenious but power-gobbling method of boosting carrying capacity much more viable.
Twenty of BitBlitzs eight-channel BBT3800 chips could be used in parallel to power a terabit-per-second serial backplane. That terabit capacity is needed to break bottlenecks in the metro areas as well as in cross-country and global optical networks. The BBT3800, which runs at 3.1 gigabits per second and consumes 1.6 watts, begins trials this month.
A chip that consumes 4.5 watts needs a heat sink or a fan to cool it. That requires even more electric power, and more room in the equipment rack. But most of the older circuit-switching offices were built before the advent of the Internet and were not designed for high-power, high-heat systems. Many of these central offices have reached their equipment capacity, which is threatening Internet growth.
BitBlitzs four-channel BBT3400, which is in trials now, is powering Internet switches and routers that move data at 3.1 Gbps. The BBT3400 consumes 800 milliwatts about a fifth the power of most chips deployed today, Wong says.