Ericsson University of Granada Ericsson Ericsson This document defines a Constrained Application Protocol (CoAP) Usage for REsource LOcation And Discovery (RELOAD). The CoAP Usage provides the functionality to federate Wireless Sensor Networks (WSNs) in a peer-to-peer fashion. The CoAP Usage for RELOAD allows CoAP nodes to store resources in a RELOAD peer-to-peer overlay, provides a lookup service, and enables the use of RELOAD overlay as a cache for sensor data. This functionality is implemented in the RELOAD overlay itself, without the use of centralized servers. The RELOAD AppAttach method is used to establish a direct connection between nodes through which CoAP messages are exchanged.