Trường Đại học Bách Khoa Hà Nội Hanoi University of Science and Technology Hệ thông Thông tin Hàng Không TS Đỗ Trọng Tuấn Bộ mơn Kỹ thuật thơng tin © HUST 2012 Trường Đại học Bách Khoa Hà Nội Hanoi University of Science and Technology Hệ thống Thông tin Hàng Không Chương Mạng Viễn thông Hàng không - ATN © HUST 2012 Teminologies ATN: Aeronautical Telecommunications Network AFTN: Aeronautical Fix Telecommunications Network AMHS: Air Traffic Service Message Handling System Development Trends Development Trends AOC : Aeronautical Operational Control, AAC : Aeronautical Administrative Communications APC : Aeronautical passenger Communication) ATSC ATN Concept ATN Applications ADS: Automatic Dependent Surveillance FIS: Flight Information Service CPDLC : Controller Pilot Data Link Communication CM: Context Management AIDC: ATS (Air Traffic Services) Interfacility Data Communication ATN Architecture ATN Architecture ATN Architecture 10 ATN Routing Domains 13 ATN Routing Protocols 14 Routers in the ATN Aircraft Operational End System Application ATN Routers perform data relay and routing functions for ATN CLNP data packets Airborne ATN Router Air-to-ground sub-network (radio) Ground sub-network (wide-area network) A/G ATN Router End System (CPDLC etc) G/G ATN Router Console Air Traffic Control Facility CM G/G ATN Router Console Airline AOC ES ATN Router functions: Data Relay ATN routers relay data packets towards their destinations The “path” across the network is determined according to least “hops”, ATSC class etc APAC ATN Backbone Network “Least hops” route: ES#1→BIS#1 →BIS#2 →BIS#3→BIS#5→ES#2 State C Backbon e BIS #4 ATS Facility BIS #1 State A Backbone BIS #2 ES #1 (e.g AMHS) ATS Facility BIS #5 State B Backbone BIS #3 ES #2 (e.g AMHS) ATN Router functions: Multiple A/G sub-networks AOC via VDL-2 ATS via VDL-3 GES A/G Router AMSS Radio Radio A/G Router VDL3 A/G Router VDL2 G/G Router Ground ATN Airline Operations Centre 17 ATCC app (e.g CPDLC) ATN Router functions: Dynamic Routeing Using dynamic routeing, routers can automatically detect damaged network elements and re-route traffic e.g due to failure of link between BIS#2 and BIS#3, traffic from ES#1 to ES#2 rerouted via BIS#4 APAC ATN Backbone Network State C Backbone BIS #4 ATS Facility BIS #1 State A Backbon e BIS #2 ES #1 (e.g AMHS) ATS Facility BIS #5 State B Backbon e BIS #3 ES #2 (e.g AMHS) ATN Router functions: Priority Handling Normally the router forwards each packet down a link in the order in which it arrives If a link is congested, CLNP NPDUs will start “queueing up” waiting to be sent, CPDLC ATIS CLNP NPDUs can be reordered if the link is congested depending on their priority Radio AOC A/G Router AOC ATIS CPDLC D-ATIS AOC ADS, CPDLC Multiple applications compete for the “narrow pipe” to the aircraft ATN routers handle CLNP NPDUs according to priority when contention for resources or congestion are occurring: Lower transit delay for higher priority messages Lower probability of higher priority messages being “dropped” ATN Router: Protocols The ATN is based on ISO Open System Interconnect (OSI) protocols ATN router functions are defined in ICAO Doc 9735-AN/956 sub-volume V • Ground/Ground (Class 4) and Air/Ground (Class 5) ATN routers must implement the IDRP routeing protocol •All Class and Class routers are Boundary Intermediate Systems (BIS) Protocols: -Network layer protocol: CLNP -Routeing protocols: - ES-IS: between End Systems and routers - IS-IS: within a routeing domain - IDRP: between routeing domains ATN or IS Router ES ES-IS ATN Router (BIS) ATN Router (BIS) ES IDRP ES ES-IS ES-IS Domain #B Domain #A Addressing within the ATN Addresses are hierarchical, based on nested address domains All addresses within a domain have the same address prefix Asia ATN Domain 470027+ Japan Fixed AINSC 470027+01 Mobile AINSC 470027+41 Mobile ATSC 470027+C1 China Fixed ATSC 470027+81 NAM USA ATN NSAP/NET Address IS O IC D e.g JCAB ATN router NET Selector (1 Octet) Area Address (11 octets) Internati Routing Domain Identifier onal (RDI) Authority 47 Common 0027 81 81 524A 00 010101 Japan ICAO Asia region Fixed ATSC domain System Identifier (6 octets) Area Identifier 0302 System Identifier 000000000000 00 System ID 00 (router) or 01 (end system) Addressing and its relationship to routeing Japan Thailand “I can reach Thailand ” “I can reach Singapore and Japan” “I can reach Singapore & Thailand” “I can reach Japan” Singapore “I can reach” = address prefix = Hierarchical addressing and domains greatly simplify routeing: Reduces routeing information exchanged by allowing routers to advertise aggregate prefixes rather than lists of addresses The router only has to inspect the prefix of a CLNP packet’s address to determine where to send it IDRP update PDU contents ATN Router Functions: Sub-network interface X.25 circuit or PSN LAN LAN ES ES ATN Router AP/ULCS ATN Router AP/ULCS CLNP Routing Protocols （ES-IS, IS-IS,IDRP） CLNP CLNP Routing Protocols （ES-IS,IS-IS,IDRP） CLNP CLNP LLC Type MAC CSMA/CD LLC Type MAC CSMA/CD X.25 （VC) LAN (Ethernet) 23 X.25 （VC) WAN LLC Type MAC CSMA/CD CLNP LLC Type MAC CSMA/CD LAN (Ethernet) Global ATN Internet The APAC Regional ATN Ground Network Source： Fifth ATN Transition Task Force Meeting – WP19 （2003.6） APAC: Asia/Pacific Region Use of APAC ATN Network for Air-Ground AES MTSAT ATN communication （CPDLC,ADS,DFIS ） Other State Japan GES ES G/G BIS ATN 26 A/G BIS Trường Đại học Bách Khoa Hà Nội Hanoi University of Science and Technology ... Communication ATN Architecture ATN Architecture ATN Architecture 10 ATN Routing Domains 11 ATN Routing Domains 12 ATN Routing Domains 13 ATN Routing Protocols 14 Routers in the ATN Aircraft Operational... Hanoi University of Science and Technology Hệ thống Thông tin Hàng Không Chương Mạng Viễn thơng Hàng khơng - ATN © HUST 2 012 Teminologies ATN: Aeronautical Telecommunications Network AFTN: Aeronautical... Application ATN Routers perform data relay and routing functions for ATN CLNP data packets Airborne ATN Router Air-to-ground sub-network (radio) Ground sub-network (wide-area network) A/G ATN Router