1. ? CLASS I Candidate CSs FOM ? Class I Class II Class III Class IV
GENERAL
Reference
CONOPS
(2011)
Software
Assurance
Level
Cross Domain
Information
Sharing
A-CDM
UAV
Systems
Operation ?
ASM
Flexible Use
Of Airspace
Airspace
Design
ATFM
IFPS
User Manual
Data
Exchange
Format
E-ATFM
(CFMU/IFPS)
ATS
OLDI
Open ATC
Architecture
Model
ATS Middleware
(ACC-ACC only)
Interoperability
Of Flight
Data Processing
A-SMGSC
(Level 1 & 2)
for interop
COM
FOM ?
Class I
NAV
GBAS
CAT I
Procedures on
Use of GPS
Class II
Class III
SURV
Surveillance
Data Exchange
Class IV
To be deleted
AIS
MET
CLASS I Candidate CSs
(started by 2006)

2. CLASS II Candidate CSs Class I Class II Class III Class IV
GENERAL
Class II
ASM
Class III
Class IV
ATFM
To be deleted
DL Services
over ATN in
Continental Airspace
DL Services
over FANS1/A in
Continental Airspace
DL Services
over ACARS in
Continental Airspace
ATS
A-SMGCS
(Level 3 & higher)
Arrival
Management
Departure
Management
Surveillance
Performance
COM
European AMHS
Profile
Telephone for ATC
purposes
Voice over IP
(ground only)
NAV
SBAS
Galileo, GNSS
SURV
Ground-based
primary radar
equipment
Multilateration
Equipment
Surveillances
Services using
ADS-B
AIS
Generic Data
Process & Principles
Integrity -
Data Origination
Integrity -
Data Publication
MET
Systems & Procedures
For the use of
MET info
CLASS II Candidate CSs
(started in 2007)

3. CLASS III Candidate CSs
GENERAL
Reference
CONOPS
(2020)
ATFM-CDM
ASM
Class I
Class II
ATFM
Advanced Data
Exchange Formats
ATS
Interfaces
CWP /
Data Processing
Interfaces with
Flight Data
Operator Positions
Interfaces with
Local centre
Sub-systems
Flight Plan
Information
Subscriber Systems
ATS Middleware
(inter & intra ACC)
COM
Directory services
In Support
of AMHS
Voice over IP
(including
air/ground)
NAV
DME ground
equipment
ILS ground
equipment
MLS
GBAS CAT II/III
SURV
Class III
Class IV
AIS
Aeronautical
Information
Exchange (AIXM)
To be deleted
MET
CLASS III Candidate CSs
(started by 2008 or later)

4. CLASS IV Candidate CSs Class I Class II Class III Class IV
GENERAL
Class I
ASM
Class II
Class III
ATFM
Class IV
ATS
Surveillance
Data Processing
To be deleted
COM
Ground and mobile
AM Stations
( – 137 Mhz)
HF radio
equipment
UHF for use by
Civil ATC
NAV
NDB
Ground equipment
VOR, D-VOR
ground equipment
VHF Marker
Beacon
Ground equipment
SURV
Ground-based
secondary radar
equipment
AIS
CLASS IV Candidate CSs
(started on demand)
MET