Thanx for a healthy discussion.
We are about to implement 50 miles reduced longitudnal separation over oceanic routes. The routes are defined as RNP10 and a suveillance of either RADAR or ADS-C is must. Now over land area with PBN SIDS and STAR surveillance of RADAR is must.
That means surveillance is required in both cases of PBN and RNP. Also equipment and sensors to be carried on board of aircraft is also specified.
Then why ICAO brings every 6 months a new term or an abbreviation for aviation which rather creates MORE OF CONFUSION.