Managing high loads in WiFi with automatic synchronization and bandwidth control

摘要

Mobile devices in industrial settings became commonplace with different handheld equipment and mobile robots using COTS WiFi interfaces for communication. This growth in the use of the wireless medium increases the potential for overload and consequent long delays and high losses. Traffic segregation with different Quality of Service (QoS) classes can attenuate the problem but does not solve it within each class. In this paper we propose an extension to the Reconfigurable and Adaptive TDMA protocol to cope with generic traffic and improve the performance of highly loaded WiFi networks. We benefit from the self-synchronization feature of the protocol to create disjoint slots without clock synchronization which are then made available to the protocol stack through a TUN/TAP virtual interface. Then we propose a cooperative bandwidth management to adjust the traffic generated by each node through the virtual interface to match the available bandwidth, granting high bandwidth utilization while avoiding overload. We validate our approach with several practical experiments that confirm the capacity to measure and track the actual bandwidth available for communication through the protocol, removing the bandwidth consumed by interference.