Broadband Communications, Networks, and Systems

Gateways in IoT infrastructures generally represent a single point of failure, thus resulting in a total loss of network operability. This paper presents the design, implementation and experimentation of a fault-tolerant protocol for a critical infrastructure applied to the field of road safety. The proposed mechanism establishes a node hierarchy to prevent loss of communication against AP failures in WLANs based on the IEEE 802.11n standard. This mechanism automates the management of the node roles by means of an election and promotion process between stations in search of designated and backup APs. The convergence times of the protocol obtained suitable values of 3.34 s for the formation of a BSS from zero, as well as 15.20 s and 18.84 s for the failover conditions of the backup and designated APs with a minimum traffic load of 42.76% over the WSN traffic.