In the old days, if you had the required equipment you could fly in a given airspace. This was specified in ICAO annexes and regional supplementary procedures, etc... This is, I understand, equipment based navigation.
Nowadays, if your equipment, whatever equipment you have as long as it is approved, meets the required navigation performance of a given airspace, then you can fly in it. This is, as opposed to the above, performance based navigation.
The NAT MNPS is a similar thing, a precursor of RNAV-RNP.
The implementation of RNAV-RNP is being progressive. It started with BRNAV, later with PRNAV. But I thought that these would both superseded by RNAV-RNP with RNP 5 and RNP 1.
But who cares! The goddamned FMS will get us where we want no matter what ICAO docs, leaflets etc they may print. I am going to drown in a sea of paper, aaaaaaaaagh
Not quite.
ICAO RNP was equipment accuracy based but PBN includes procedures.
EU BRNAV and PRNAV will eventually become RNAV - 1 and RNAV - 5. Note they are not RNP specifications as they do not need onboard performance monitoring and allerting.
The RNAV 1 specification shows that any of the following navigation sensors can meet its performance requirements: GNSS or DME/DME/IRU or DME/DME.
However, a limited DME infrastructure or GNSS policy may lead the authorities to impose specific navigation sensor requirements for an RNAV 1 specification in that State.
Example:
State A's AlP could stipulate GNSS as a requirement for its RNAV 1specification because State A only has GNSS available in its navaid infrastructure.
State B's AlP could require DME/DME/IRU for its RNAV 1 specification (policy decision to not allow GNSS).
Each of these navigation specifications would be implemented as an RNAV 1 application.
However, aircraft equipped only with GNSS and approved for the RNAV 1 specification in State A would not be approved to operate in State B.