Performance Evaluation of Switching Between WiFi and LiFi under a Common Virtual Network Interface

We consider a hybrid wireless local area network composed of both WiFi and LiFi Access Points (AP) and wireless devices. Each device is identified in the network by a unique IP address, using a virtual network interface obtained by bonding the WiFi and LiFi physical interfaces, implemented through commercially available products. We measure the time it takes to switch between the two physical interfaces and its impact on the traffic flow, under different settings of the mechanisms used by the interface bonding driver. Different specific triggering events are considered for the switch, namely: an (simulated) interface malfunctioning or unintended shutdown, a signal loss, and a manual (intended) switch. Our experimental results show that the different types of triggering events have an impact on the time it takes to reconfigure the currently active physical interface (which is used by the virtual interface to send/receive data), with connection recovery times ranging from few tens milliseconds to few seconds. This entails a packet loss on active flows which, in the worst case, we quantify in a maximum loss of up to 1% of the traffic flowing during 1 second.