The existing cellular infrastructure has been criticized
as being expensive and inflexible, suffering from complex
control plane protocols and vendor-specific configuration
interfaces [1,2]. In order to simplify the management of
cellular data networks, the pioneering project CellSDN [1]
proposes a SDN design for the cellular core infrastructure.
Because applying SDN to cellular environment needs to
address several challenges, including user mobility and
real-time adaptation, a set of necessary extensions are
identified for the key elements of CellSDN architecture.
On the proposed controller extension, policies of subscriber
attributes are translated into switch rules that match on
packet headers. A local control agent is introduced on the
switch to alleviate the scalability issue of central controlling
by performing localized actions guided by the control
platform.