This deliverable presents the initial research outcomes from the AMBIENT-6G project on techniques and protocols for energy neutral devices (ENDs) and their integration into future 6G networks. It consolidates early investigations across multiple protocol layers, addressing the challenges posed by devices operating with intermittent and extremely constrained energy resources. At PHY, novel synchronization, modulation, and waveform designs are analyzed to reduce complexity and power consumption, while backscatter and symbiotic communication techniques are examined with emphasis on signal modeling, interference management, and hardware-level integration. The study also explores RF charging mechanisms, with results showing efficiency gains from distributed multi-antenna architectures and highlighting the importance of hardware–protocol co-design. At higher layers, MAC and RRC innovations are introduced, including energy-aware and lightweight channel access and scheduling, and supporting frameworks. Furthermore, network-level concepts are introduced for optimized architecture management and goal/context-aware scheduling, alongside initial security-by-design frameworks tailored to ultra-constrained devices. Overall, the deliverable establishes the technical basis for the development of lightweight 6G protocols that support sustainable and dependable operation of ENDs, paving the way for subsequent research and system integration activities.