“IBM’s concept is not totally new but rather a combination of familiar themes,” such as software-defined radio, network equipment virtualization, and networks as software,” says Dipankar Raychaudhuri director of the Wireless Information Network Laboratory (WINLAB) at Rutgers University. But the work is part of an important trend, Raychaudhuri says, with research moving steadily toward early technology implementations, he says. “For example, there is a U.K. company called picoChip that offers a variety of base stations in software using the same parallel computing platform,” he says.
“I think there is a good, strong argument to use software radio in base stations,” says David Grace head of the communications research group at the University of York, U.K., and chair of the World Universities Network Initiative on Cognitive Communications. Grace says the approach is capable of handling the signal processing required of base stations, but he is less convinced about the need to relocate this software and absorb it within the cloud. “It’s the old argument of whether to centralize or distribute,” he says.
Centralizing software in the cloud would allow for more efficient use of processing resources and would make future upgrades considerably faster and cheaper, Grace says. “The disadvantage is, you have to introduce the additional communication between devices to allow that to happen,” which can cause problems. Even with analog-to-digital converters at the antennas, the raw streams of data they would create would be of very high frequencies. Processing this is notoriously difficult because it requires even higher frequency sampling, he says.
Even so, IBM appears to have managed it. “We already have a prototype for WiMax,” says Lin. This has demonstrated that a general-purpose data server can handle the software radio requirements, she says. The team is now developing a prototype 4G mobile phone network and is talking to mobile operators in China.
The potential for WNC is huge, says Shao. Beyond reducing infrastructure costs for network providers, it will improve their ability to manage mobile virtual network operators–phone companies that own no infrastructure and instead lease it off larger companies. And although WNC would be most suitable for urban areas with very high density, it could also help in rural areas where network nodes can be hard to access and have unreliable power supplies, he says.