AeroFlux: A Near-Sighted Controller Architecture for Software-Defined Wireless Networks

Applying the concept of SDN to WiFi networks is challenging, since wireless networks feature many peculiarities and knobs that often do not exist in wired networks: obviously, WiFi communicates over a shared medium, with all its implications, e.g., higher packet loss and hidden or exposed terminals. Moreover, wireless links can be operated in a number of different regimes, e.g., transmission rate and power settings can be adjusted, RTS/CTS mechanisms can be used.

Indeed, due to the non-stationary characteristic of the wireless channel, permanently adjusting settings such as transmission rate and power is crucial for the performance of WiFi networks and brings significant benefits in the service quality, e.g., through reducing the packet loss probability. Today’s rate and power control is mainly done on the WiFi device itself. But it is rarely optimized to the application-layer demands and their diverse traffic requirements, e.g., their individual sensitivity to packet loss or jitter. Therefore, if SDN for wireless can provide mechanisms to control the WiFi-specific transmission settings on a per-slice, per-client, and per-flow level, traffic and application-aware optimizations are feasible.