BIG AP – Seamless Handover in High Performance Enterprise IEEE 802 . 11 Networks

Enterprise IEEE 802.11 networks need to provide high network performance to operate a large number of diverse clients like laptops, smartphones and tablets as well as capacity hungry and delay sensitive novel applications like mobile HD video & cloud storage efficiently. Moreover, such devices and applications require much better mobility support and higher QoS/QoE. Existing solutions can either provide high network performance or seamless mobility but not both. We present BIGAP, a novel architecture achieving both of the above goals. The former is achieved by assigning different channels to co-located APs in order to fully utilize the available radio spectrum. The latter is achieved by providing a mechanism for below MAC-layer handover through exploiting the Dynamic Frequency Selection capability in 802.11. In essence BIGAP forces clients to change AP whilst they ’believe’ they are simply changing channel. BIGAP is fully compatible with 802.11 and requires no modifications to the wireless clients. Testbed results demonstrate a significant improvement in terms of network outage duration (which is 32× smaller as compared to state-ofthe-art solutions) and negligible throughput degradation during handover operation. In this way frequent and seamless handover operations can take place thus supporting both seamless mobility and efficient load balancing.