5G is arguably the most energy-hungry mobile technology yet, with a scalability close to the limit of what the planet and society can environmentally and practically afford. There is already plenty of research towards sustainable and zero-energy end-devices, but huge gains in the energy efficiency and sustainability of the power-hungry network infrastructure behind them are still to be achieved. SAMBAS’ project vision represents a holistic approach in driving a significantly more sustainable B5G/6G wireless communications network, where joint considerations of radical innovations at radio, network, and service levels will lead to critically reduced power needs. SAMBAS contributes towards this goal by developing an innovative sustainable millimetre wave (mmWave) micro base station (µBS) that makes effective use of renewable energy harvesting in combination with extremely energy-efficient hardware, and communications protocols to reduce power consumption >99%. At the networking level, we aim to reduce signalling overhead and energy requirements by an order of magnitude through distributed in-band context dissemination and energy-aware networking. Finally, through joint energy-aware network and cloud resource optimization, a sustainable end-to-end mmWave-based system will be developed. We target B5G performance in terms of latency, ultra-high-capacity data rates, reliability, and range, while targeting a significant reduction in the reliance on non-renewable energy sources. An integrated prototype will be validated via a multi-user indoor interactive virtual reality application, and an outdoors vehicular communications application.