As we predicted the third generation ATSC version of DTT was a major talking point at NAB and featured in at least two separate demonstrations. This highlighted what we had also pointed out earlier, which was how ATSC has taken over from DVB as the driving force taking DTT into the IP and Ultra HD era. Essentially ATSC 3.0 has incorporated the best bits of DVB T2 including the fundamental OFDM (Orthogonal Frequency Division Multiplexing) and added refinements that address the challenges facing broadcasting as it converges with IP. These come under the headings of capacity, flexibility and extensibility. On the capacity front, key attributes wanted included ability to deploy multiple HD programs over a single RF channel and to…