Route Segment Two subsequently related waypoints (or ATD fixes) define an RNAV route segment.
Router A router is the communication element that manages the relaying and routing of data while in transit from an originating end system to a destination end system. An ATN router comprises an OSI intermediate system and end system supporting a systems management agent.
Routine Area A routing area is a routing sub domain comprising one or more ISs, and optionally one or more ESs.
See Intermediate System and End Service / System.
Routine Domain Identifier
An RDI is a generic NET as described in ISO 7498, and is assigned statically in accordance with ISO 8348. An RDI is not an address, and cannot be used as a valid destination of an ISO 8473 PDU. However, RDIs are, like ordinary NETs, assigned from the same Addressing Domain as NSAP Addresses.
Routing
A function within a layer which uses the address to which an entity is attached in order to define a path by which that entity can be reached.
Routing Domain
A set of end systems and intermediate systems which operate the same routing protocols and procedures and which are wholly contained within a single administrative domain. A routing domain may be divided into multiple routing sub domains.
Routing Domain Confederation
A Routing Domain Confederation is a set of Routing Domains and/or RDCs which have agreed to join together and form a Routing Domain Confederation. The formation of a RDC is done by private arrangement between its members without any need for global co-ordination.
Routing Information Base
A data base which is maintained by each router and comprises the information regarding the connectivity and topology of the ESs and ISs within a particular Routing Domain and path information pertinent to paths interconnecting Routing Domains. It is maintained by way of the information received by a routing information exchange protocol. Each Routing Information Exchange Protocol has its own RIB specification.
Routing Information Exchange Protocol
The protocol used to exchange sub network connectivity information between end systems and
intermediate systems and between intermediate system and intermediate system.
Routing Policy
The set of rules in a BIS which determines the advertisement and use of routes is known as a Routing Policy. Each organisational user of the ATN must determine and apply his own Routing Policy.
RTCA DO-136
RTCA Document 136, Universal Air-Ground Digital Communication System Standards, Issued 03/68. This document recommends universal digital standards for lifting aircraft into the ground communications and data processing environment of the air traffic control system and airlines and military management information systems.

 
RTCA DO-144
RTCA Document 144, Minimum Operational Characteristics - Airborne ATC Transponder Systems, Issued 03/7O (TSO C47e). Part I of the document defines the concepts, philosophy and development of MOCs for airborne systems and Part II covers the MOCs, for Airborne ATC Transponder Systems, including system characteristics; provides information for demonstration of compliance and guidance material.