ONF Group to Explore SDN in LTE
The Open Networking Foundation (ONF) is formally launching a new working group to focus on how to use software-defined networking (SDN) in mobile networks, but it's actually been a long time in the making.
The nearly three year-old non-profit, formed to promote the use of the OpenFlow protocol, announced the Wireless and Mobile Working Group on Tuesday, along with the appointment of Dr. Serge Manning, Huawei Technologies Co. Ltd. 's senior manager for corporate standards, as chair of the new group. The group, one of twelve in the Open Networking Foundation , was created to study use cases and the architectural and protocol requirements needed to extend OpenFlow to the wireless domain. (See SDN's Northbound Ascent and ONF Completes Latest OpenFlow PlugFest.)
The wireless group actually began meeting a year ago as a discussion group after Manning co-authored a solution brief, "OpenFlow Enabled Mobile and Wireless Networks," a 55-page document he trimmed down to 10 pages for easier reading. It became an official charter of the ONF in the fall, and Manning was approved as the chairman this month.
The group's goal is to build a common-ground architectural framework for applying OpenFlow technologies to mobile networks so that they can keep up with the demands operators face. Manning says SDN in mobile networks hasn't been studied extensively to date, but he anticipates the use cases, like the motivators -- exploding traffic volumes, the need for new services, and greater network complexity -- will be quite similar to fixed-line networks.
"Our goal is to use SDN and OpenFlow to make [wireless networks] dynamic and adaptable to apps, and bring the same advantages of fixed over to cellular," he says. "Most will work, but some areas, like how you identify flow in EPC [evolved packet core], may need additional parameters to make it work efficiently."
Manning said the group has had use cases coming from all directions, but it's starting with a focus on three areas: the mobile packet core, wireless backhaul, and integrated fixed/wireless operation in the enterprise. These use cases are finished, he says, and will be made public soon.
"This year, we're looking at architectural and protocol requirements with OpenFlow to see where we need to do enhancements," he says. "We're trying to explore specific ways SDN and OpenFlow can be used."
That's easiest to do in the EPC because 3rd Generation Partnership Project (3GPP) standards have already identified a control-signaling plane separate from the data plane. But, Manning says, the gateways in place are combined. The ONF wants to see if it can use OpenFlow to distribute them out to the edge while keeping the control plane and 3GPP interfaces the same.
"Our customers, operators, have a lot invested in 3GPP," he says. "How can we add SDN into cellular and make it better?"
A selling point in the early days of SDN is the fact that operators can be aggressive as they want -- applying SDN technologies to part of the network or the whole thing. Manning said doing just an experimental portion, such as only small cells, or only one geography, will simply mean that segment performs better, but still ties in with billing and back-office promises. When the operator is ready to go fully programmable, it'll be an easy migration path.
With all their growth and the deployment of new LTE network, mobile operators have more greenfield opportunities than their fixed-line colleagues, and the greenfield opportunity is always the ideal time to try something new to leapfrog what's been done in the past, adds ONF Executive Director Dan Pitt. "But if we waited for greenfield, it'd be a long road," he adds. "With a technology as disruptive as this one, they can get started and then gradually migrate traffic."
— Sarah Reedy, Senior Editor, Light Reading