When is a femtocell not a femtocell? And does it matter?
PicoChip’s latest chip, the PC333, is designed to take the femtocell, until now a technology aimed at the residential and small business sector, into the public access area. The chip will be available in Q4 of this year to customers.
PicoChip’s CTO Doug Pulley said that the time has come for operators to deploy cells with femtocell characteristics not just as a coverage solution in the residential space, but to provide coverage or capacity in metro or rural environments.
“Operators and vendors are pulling this out of us,” he said. “They can’t get access to it fast enough. We have a team of people dedicated to getting this out of the door as early as possible.”
Pulley said that the PicoChip design will support 32 channels for the full range of services an operator wants to deliver. PicoChip’s smartSignaling technology, which reduces the signaling load delivered from the femtocell to the network, could enable up to 400 users to be supported simultaneously. The chip is also the first femtocell design to be Local Area Basestation (LABS) standard compliant. LABS specifies functionality such as 120km/h mobility and +24dBm output power for greater than 2km range.
Pulley added that when other systems designers talk about “outdoor” femtocell, operators need to ask they are really providing the support required to provide multi-services access to users. He mentioned such features as receive diversity, and processing power. “It’s simply a matter of horsepower,” added Andy Gothard, Director of Corporate Marketing at PicoChip.
Despite operators like Vodafone Germany deploying rural LTE coverage using 800MHz, Pulley said there would be “no getting away from” the need to provide spots of higher capacity – even in rural environments. Similarly, DAS (Distributed Antenna Systems) extend coverage, but don’t solve the capacity issue.
So what makes a public access base station, deployed by the operator either to provide coverage or capacity, a femtocell? Partly it goes back to the original standards that the femtocell defined – around self organisation and optimization, interference management, and plug and play deployment.
Most importantly, though, a femtocell is a femtocell because it brings consumer electronics economics to telecoms infrastructure, Pulley claimed. “It’s about moving from the blade/rack approach to a consumer electronics approach. And that is genuinely revolutionary,” he said.
“The innovation that enabled the low cost residential femtocell has much wider ramifications,” Pullet said. As an example he gave the way SON functionality, which was an LTE standards item, has been pulled forwards into HSPA and 3G femtocells. But he also pointed to RF chip and chipset development.
“Once you have that bundle of technologies you can do all sorts of other things too,” he concluded.
But what questions does the deployment of increasing numbers of small cells raise for operators? One is backhaul. Residential femtocells can sit on the end of a DSL line, but how could an operator deploy in public? And would that operator be happy with the QoS that they could be provided on infrastructure they don’t own?
Pulley said that the holy grail would be some wireless technology, perhaps line of sight or “near line of sight” that connected back to the network.