Colt began a trial of FaaS in October last year with an unnamed mobile operator in Europe, using a femto gateway from NEC Corp. and femtocell access points from Ubiquisys Ltd. So far, the trial has connected just six enterprise femtocells, but that has been enough to show that this idea can work as a real service for mobile operators.

"We can prove that the concept works," says Valerie Layan, VP of wireless at Colt. "Mobile operators are paying much more attention to it now that this is real."

Here's the FaaS concept in a nutshell: The NEC femto gateway is hosted in one of Colt's 20 data centers in Europe; Colt provides the connectivity from the gateway to one or more mobile operators' core networks; the mobile operators then pay a monthly subscription fee for each femto access point they connect to the gateway.

In this scenario, the mobile operator does not have to shell out the capex for a femto network gateway, which can cost at least €1 million (US$1.3 million), according to Colt's Layan. And Colt believes that removing this capex cost will break down one of the barriers to femtocell rollouts for mobile operators.

"We can bring down the cost from a capex to a pure [operating expenditure] model," says Layan. "There are a lot of precedents of some kind of network sharing or outsourcing -- [FaaS] takes it one step further."

Why this matters
Colt's femto-as-a-service could be a catalyst for a ramp-up in femtocell rollouts in Europe. As many mobile operators face capex constraints, an infrastructure hosting service such as this could reduce some of the risk of a femto business case.

For more

• Femto Revival Rumblings
• NEC, Colt Trial Femto-as-a-Service

— Michelle Donegan, European Editor, Light Reading Mobile