The main objective of this paper is to present a DAB protocol and a DAB grid agent prototype, as essential parts of a grid ancillary services operational model. The decentralized, small electric loads (electric vehicles, household-appliances, batteries, prosumers), clustered properly by aggregators are equipped in large amounts with the so called “grid-agents”. A grid-agent is a cost-effective, low-power, smart electric control unit consisting of a DAB+ receiver with embedded circuits for local grid voltage and frequency measurements and a microcontroller running algorithms for flexible load control. The grid-agent will optimize the electricity demand with respect to the grid status and/or to external commands received via DAB+. Moreover, especially suited for Transmission System Operators (TSOs), multi-load power facilities that are controlled by energy management systems through specific standards (e.g. KNX for hotels, Modbus for the industrial sector, etc) and even Renewable Energy Sources (RES) Distributed Generators (DGs) are equipped with a single DAB+ grid-agent.