SoftMoW: A Dynamic and Scalable Software Defined Architecture for Cellular WANs

Rather than organizing mobile wide area networks as rigid regions with no direct traffic transit, we argue that the cellular networks should have a fully connected core topology, small logical regions, and more egress points. In addition, operators should leverage software dened networking to manage the entire network with a logically-centralized controller. The controller directs traffic through efficient network paths that might cross region boundaries, supports and optimizes inter-region handoffs, and dynamically adapts to traffic patterns with efficient inter-region traffic engineering.

Such an architecture raises unique scalability challenges in comparison with data-center and enterprise networks due to the geographically distributed nature of mobile WANs. Indeed, a logically-centralized controller in one point-of-presence with a at architecture quickly becomes infeasible, if the mobile WAN spans a large region. This is due to the high latency between the controller and the data plane switches, the amount of signaling load from mobile users, and the very high number cellular handoffs.