Silicon Labs This document defines the mesh link establishment (MLE) protocol for establishing and configuring secure radio links in IEEE 802.15.4 radio mesh networks. MLE extends IEEE 802.15.4 for use in multihop mesh networks by adding three capabilities: 1) dynamically configuring and securing radio connections between neighboring devices, 2) enabling network-wide changes to shared radio parameters, and 3) allowing the determination of radio link quality prior to configuration. MLE operates below the routing layer, insulating it from the details of configuring, securing, and maintaining individual radio links within a larger mesh network.