This is the final report of WP1 Robust group communications for mobile ad hoc networks, within NORDEFCO "Group-communication for military Mobile Ad Hoc Networks (MANET)". The work is a joint effort by FOI and FFI. In military networks a large part of the traffic is group communication, often called broadcast/multicast, that is, traffic aimed for multiple nodes. We study properties and improvements of two of the most interesting technologies for forwarding of group traffic to the interested receivers (multicast group). The study is performed for mobile military ad hoc networks, and the two technologies are Synchronized Cooperative Broadcasting (SCB) at layer 2 and Simplified Multicast Forwarding (SMF) at layer 3.