ACP/WGN 09/SGN1

WP-905

06/26/06

1(27)

ANNEX 10, VOLUME III, PART 1 AMDT 79 - 25 NOVEMBER 2004

/
International Civil Aviation Organization
WORKING PAPER / WGN06-WP09
18 June 2006

AERONAUTICAL COMMUNICATIONS PANEL (ACP)

WORKING GROUP N (Networking) Sixth meeting

Brussels, Belgium; 3-7 July 2006

Agenda Item : / 3.1

(Presented by the Secretary)

CHAPTER 3. AERONAUTICAL TELECOMMUNICATION NETWORK

(including changes as reviewed by the Air Navigation Commission

in November 2005)

Proposed amendments to:

  1. incorporate IPS
  2. update existing SARPs in accordance with ANC guidelines

Note Secretary: Definitions of terms used in the Standards and Recommended Practices which are not self-explanatory in that they do not have accepted dictionary meanings. A definition does not have independent status but is an essential part of each Standard and Recommended Practice in which the term is used, since a change in the meaning of the term would affect the specification.
The definitions in the material below have been evaluated against the principles above and action in accordance with the requirements for definitions are proposed.

3.1 DEFINITIONS

Note 1.— The following definitions were taken from ISO/IEC 7498-1, Information technology — Open Systems

Interconnection — Basic Reference Model (Reference: ITU-T Rec. X.200 (1994)) and from ICAO Doc 9705 — Manual of Technical Provisions for the Aeronautical Telecommunication Network (ATN).

Note 2.— ICAO Doc 9705 has evolved through multiple editions. Each sub-volume of that document indicates the evolution of the provisions between successive editions.

Note 3.— Sub-volume I of ICAO Doc 9705 provides a cross-reference chart between versions (i.e. embedded software capabilities) and editions (i.e. technical provisions).

Note: Detailed technical specifications for the ATN are contained in Docs 9705 and XXX respectively. These documents also contain a detailed description of the ATN, including details on the Standards and Recommended Practices below.

Note Secretary: the notes above are no longer relevant because of the introduction of material in the SARPs for an ATN that is based upon the Internet Protocol Suite (IPS). The added note refers to the detailed technical specifications for the ATN, for ATN/OSI in Doc. 9705 and for ATN/IPS in Doc. XXX respectively. See also the proposal to remove paragraph 3.2 from Annex 10

Application integrity check. A small amount of additional information transferred with an application message and used to provide proof to a recipient of message content integrity. When the Integrity Check is computed, it maybe computed over more than just the message itself e.g. sender and receiver identifiers (and hence used to provide additional proofs (e.g. delivery to the intended recipient and/or authorization of the sender). The type of proof offered depends on the algorithm used to generate/verify the Application Integrity Check. A cryptographic checksum and/or use of a shared secret may be required to provide proof of origin (authentication of the sender).

(ADD-ACP-WGW-01)

Note secretary: The definition above is rather explanatory material than a definition. In addition, the terms application integrity check or application integrity are used in the SARPs. Deletion is proposed.

Accounting management. An ATN systems management facility to monitor users for use of network resources. and to limit the use of those resources.

Note secretary: The definition above is rather confusing since the accounting management is not a mechanism to limit the use of the ATN network resources. Deletion is proposed. (See also proposal for paragraph 3.8)

ADS application. An ATN application that provides ADS data from the aircraft to the ATS unit(s) for surveillance purposes.

Note secretary: The definition above is self explanatory. It is obvious that an ADS application is providing ADS (data). The definition for Automatic Dependent Surveillance below is sufficient. Deletion is proposed.

Aeronautical administrative communication (AAC). Communication used by aeronautical operating agencies relatinged to thenon-safety communications for thebusiness aspects of operating their flights and transport services. This communication is used for a variety of purposes, such as flight and ground transportation, bookings, deployment of crew and aircraft or any other logistical purposes that maintain or enhance the efficiency of over-all flight operation.

Note secretary: The first part of the definition is sufficient. The second part is not necessary since it is adding examples of AAC. Where necessary, these examples should be included in the relevant guidance material.

Aeronautical operational control (AOC). Communication required for the exercise of authority over the initiation, continuation, diversion or termination of flight for safety, regularity and efficiency reasons.

Note secretary: This definition needs to be checked against the definition for AOC in [Annex 6]. It may be better to reference [Annex 6] in this definition.

Aeronautical passenger communication (APC). Communication relating to the non-safety voice and data services to passengers and crew members for personal communication.

Note secretary: This definition above needs to be deleted. APC is not part of ANY aeronautical communication application contained in the ICAO Annexes.

AIDC application. An ATN application dedicated to exchanges between ATS units (ATSUs) of air traffic control (ATC) information in support of flight notification, flight coordination, transfer of control, transfer of communication, transfer of surveillance data and transfer of general data.

Note secretary: The definition above seems to rather re-define the definition for AIDC below than to explan that an AIDC application is an application that supports AIDC. However, this a definition (for AIDC application) is not necessary since it is clear that an AIDC application is an application supporting AIDC. The definition for AIDC below is sufficient. Deletion is proposed.

Air traffic service. A generic term meaning variously, flight information service, alerting service, air traffic advisory service, air traffic control service (area control service, approach control service or aerodrome control service).

Note secretary: This definition needs to be checked against defin itions for ATS in Annexes 2. 6 or 11. A reference to these (this) definition is proposed. The definition above is self explanatory.

Application. The ultimate use of an information system, as distinguished from the system itself.

Note secretary: This definition is not necessary since the meaning of application is well understood. Deletion is proposed.

Application entity (AE). Part of an application process that is concerned with communication within the ATN OSI environment. The as pects of an application process that need to be taken into account for the purposes of OSI are represented by one or more AEs.

Note secretary: This definition is may not apply only to the OSI environment since it is also used at instances that are not specific to the ATN/OSI. Changes to the definition are proposed. However, the remaining definition is still not clear and may need updating. It is not clear why an application should be concerned with communication. This is taking place at lower layers (both in the OSI and the IPS environment) and should not be4 mixed with the application itself.

Application information. Refers to the application names (e.g. AE qualifiers such as ADS and CPC), version numbers, and addresses (the long or short TSAP, as required) of each application.

Note secretary: With a clear definition for application entity, a definition for application information is not necessary, since the words are self-explanatory. Application information is information relating to the application and the name of it is just one element of the application. Deletion is proposed.

ATIS application. A FIS application that supports the D-ATIS.

Note secretary: This definition is not necessary since the meaning of application as well as of D-ATIS is well understood. Deletion is proposed.

ATN directory services (DIR). A service which provides the capability for an application entity or user in the ATN community to query a distributed directory data base and retrieve addressing, security and technical capabilities information relating to other users or entities within the ATN community.

Note secretary: Check whether a generic definition for directory service is available. If so, there may not be a need to define an ATN directory service, in which case deletion is proposed.
A directory service is a software application — or a set of applications — that stores and organizes information about a computer network's users and network shares, and that allows network administrators to manage users' access to the shares. Additionally, directory services act as an abstractionlayer between users and shared resources.
A directory service should not be confused with the directory itself, which is the database that holds the information about objects that are to be managed by the directory service. The directory service is the interface to the directory and provides access to the data that is contained in that directory. It acts as a central authority that can securely authenticate resources and manage identities and relationships between them

ATN security services. A set of information security provisions allowing the receiving end system or

intermediate system to unambiguously identify (i.e. authenticate) the source of the received information and to

verify the integrity of that information.

Note secretary: It is questionable whether the definition of ATN security service is necessary, since the term is self explanatory. Check with generic definitions. There is nothing specific in “ATN” security services compared to security services. Is the list complete?

ATN systems management (SM). A collection of facilities to control, coordinate and monitor the resources which allow communications to take place in the ATN environment. These facilities include fault management, accounting management, configuration management, performance management and security management.

Note secretary: This definition should be deleted. It is proposed to move all material on system management in the SARPs to guidance material for information purposes since there is no need to regulate SM on a global basis. There are other option to perform system management compared to those in the SARPs/Guidance material. At best, the SARPs could specify that a form of system management is required (in which case the definition needs to be retained.)

ATSC class. The ATSC class parameter enables the ATSC user to specify the quality of service expected for the offered data. The ATSC class value is specified in terms of ATN end-to-end transit delay at 95 per cent probability.

Note secretary: This definition is not clear (see definition for transit delay below). A new definition for end-to-end delay may be necessary. Also check with OPLINKP document on RCP.

ATS communications (ATSC). Communication related to air traffic services including air traffic control, aeronautical and meteorological information, position reporting and services related to safety and regularity of flight. This communication involves one or more air traffic service administrations. This term is used for purposes of address administration.

Note secretary: This definition is not necessary since the meaning of ATS communications is well understood in the light of the definition of ATS. Deletion is proposed.

ATS interfacility data communication (AIDC). Automated data exchange between air traffic services units, particularly in regard to co-ordination and transfer of flights.

Note secretary: The amendment proposed is necessary since AIDC is (may?) not be restricted to coordination of transfer of flight. It is obvious that data exchange serves the purpose of coordination in general.

ATS message handling service (ATSMHS). An application consisting of procedures used to exchange ATS messages in store-and-forward mode over the ATN such that the conveyance of an ATS message is in general not correlated with the conveyance of another ATS message by the service provider. (MOD-ACP-WGW-01)

ATS message handling system(AMHS). The set of computing and communication resources implemented by ATS organizations to provide the ATS message handling service. (ADD-ACP-WGW-01)

Note secretary: This difference between the service and the system is confusing in these definitions. Are these two definition really necessary? Is one not sufficient (since a system in general is providing a service??)

ATS unit (ATSU). A generic term meaning variously, air traffic control unit, flight information centre or air traffic services reporting office.

Note secretary: The fact that an ATS unit provides air traffic services (or FIS or is the ATS reporting office) is well understood. Deletion is proposed.

Authentication. A process used to ensure the identity of a person/user/network entity.

Note secretary: This definition is not necessary since the meaning of application is well understood. Deletion is proposed. The word is only used in the definition for security management and, if necessary, could be clarified in that definition. Deletion here is proposed.

Authorized path. A communication path that the administrator (s) of the routing domain(s) has pre-defined as

suitable for a given traffic type and category.

Automatic dependent surveillance Contract (ADS-C). A surveillance technique in which aircraft automatically provide, via a data link, data derived from on-board navigation and position-fixing systems, including aircraft identification, four-dimensional position, and additional data over the ATN.

Note secretary: Check with Secretary OPLINKP. In addition, since in the context of ATN ADS only refers to ADS-contract, a further precision is proposed

Automatic terminal information service (ATIS). The automatic provision of current, routine information to arriving and departing aircraft throughout 24 hours or a specified portion thereof.

Digital Data link-automatic terminal information service (D-ATIS). The provision of ATIS via data link.

Note secretary: This definition should refer to digital ATIS and needs to be checked against similar definition(S) elsewhere in ICAO annexes. However, similar to D-FIS, the meaning of D9igital) ATIS is well understood)

Voice-automatic terminal information service (Voice-ATIS). The provision of ATIS by means of continuous and repetitive voice broadcasts.

Note secretary: Digital voice? Different from D-ATIS?) In any case, the term is not used in the SARPs and can be deleted.

Configuration management. An ATN systems management facility for managers to change the configuration of remote elements.

Note Secretary: Is the configuration management restricted to remote elements (of the ATN)? It is used only in the section addressing systems management, which is proposed to be deleted. This definition can also be deleted.

Context management (CM) application. An ATN application that provides a log-on service allowing initial aircraft introduction into the ATN and a directory of all other data link applications on the aircraft. It also includes functionality to forward addresses between ATS units.

Note.— Context management is a recognized OSI presentation layer term. The OSI use and the ATN use have

nothing in common.

Context management (CM) server. An ATS facility that is capable of providing application information relating to other ATSUs to requesting aircraft or ATSUs.

Note Secretary: This is confusing. The CM application is an ATN application providing a log-on service. It also provides a directory of all data link applications on the aircraft. It also includes functionality (?)to forward addresses. But the CM server is an ATS facility capable of providing application information to other ATSU’s to requesting aircraft or ATSU’s. A CM server is a server enabling CM applications. Revision/clarification is needed. The note can be deleted.

Controller pilot data link communication (CPDLC). A means of ATC data communication between controller and pilot, using air-ground data link. for ATC communications.

Note Secretary: A minor change to the definition is proposed.

CPDLC application. An ATN application that provides a means of ATC data communication between controlling, receiving or downstream ATS units and the aircraft, using air-ground and ground-ground subnetworks, and which is consistent with the ICAO phraseology for the current ATC voice communication.

Note Secretary: This definition is not necessary since it is clear that a CPDLC application is an application providing CPDLC.

Data integrity. The probability that data has not been altered or destroyed.

Note Secretary: This definition is not necessary.

D-METAR. The symbol used to designate data link aviation weather report service.

Note secretary: Should this definition not refer to digital METAR? In any case, it is only used in the definition for METAR and not further in the SARPs. Deletion is proposed

End system (ES). A system that contains the OSI seven layers and contains one or more end user application processes.

Note Secretary: In IPS systems, the end system is called a host and contains only the four IPS layers. A definition for hast could be considered and if agreed, in the definition of end system the definition for host should be referenced.

End-to-end. Pertaining or relating to an entire communication path, typically from (1) the interface between the information source and the communication system at the transmitting end to (2) the interface between the communication system and the information user or processor or application at the receiving end.

Note Secretary: This definition can be deleted since there is a general understanding of what end-to-end means. It is not specific to ATN SARPs.

Entity. An active element in any layer which can be either a software entity (such as a process) or a hardware entity (such as an intelligent I/O chip).

Note Secretary: This definition can be deleted since it is only used in the SARPs in relation to application entity. There is already a definition for application entity.

Fault management. An ATN systems management facility to detect, isolate and correct problems.

Note Secretary: In consideration of the proposal to remove section 3.8 on system management from the SARPs, this definition can be deleted.

FIS application. An ATN application that provides to aircraft information and advice useful for the safe and efficient conduct of flights.

Note Secretary: A FIS application is an application within the flight information service. This definition is not necessary in the light of the definition for FIS below.

Flight information service (FIS). A service provided for the purpose of giving advice and information useful for the safe and efficient conduct of flights.