International audienceWe present a precise description IoT-LAB. IoT-LAB provides a very large scale infrastructure facility suitable for testing small wireless sensor devices and heterogeneous communicating objects. IoT-LAB features over 2700 wireless sensor nodes spread across six different sites in France. Nodes are either fixed or mobile and can be allocated in various topologies throughout all sites. A variety of wireless sensors are available, with different processor architectures (MSP430, STM32 and Cortex-A8) and different wireless chips (802.15.4 PHY @ 800 MHz or 2.4 GHz). In addition, “open nodes” can receive custom wireless sensors for inclusion in IoT-LAB testbed. IoT-LAB's main and most important goal is to offer an accurate ...