International Civil Aviation Organization INFORMATION PAPER CP WGI 19/-01 20-22 January 2016 COMMUNICATIONS PANEL (CP) WORKING GROUP I (WG-I) Montreal, QC Canada 20-22 January 2016 Agenda Item 4: Completion/evolution of the ATN/S work S over VDLm2 Feasibility Demonstration (Prepared by Boeing, Honeywell, SITA) Presented by Michael Olive, Honeywell International Inc., United States) SUMMARY This information paper presents collaborative presents an overview of collaborative research and development by Boeing, Honeywell, and SITA to demonstrate the feasibility S (per ICAO Doc. 9896) over the existing narrowband VDLm2 datalink. ACTION The working group is invited to review the information presented. (10 pages) WGI19 /01 S-over-VDLm2 Demo_20160120.pdf
Background Industry Research on S [1/2] 1 Boeing Research & Technology (BR&T) and Honeywell Advanced Technology initiated a Joint Research Project to pursue common interests related to ATN using Internet Protocol Suite (S) per ICAO Doc. 9896 - Implementation constraints and impact on current aircraft architectures - Prototyping using representative avionics hardware - Feasibility demonstrations using live communications environments - Promoting further definition, investigation and standardization of the airground technical provisions The 2015 project focused on demonstrating the feasibility of S over the existing narrowband VHF Datalink Mode 2 (VDLm2) - SITA was brought onto the team to provide VDLm2 subject matter expertise and equipment
2 Background Industry Research on S [2/2] 2015 Industry Research Participant Contributions Boeing - Integrated Avionics Systems Laboratory (IASL) test facilities including 737 avionics test bench and associated VHF antennas and cabling Production avionics equipment: FMC, MCDU, VDR, etc. - Prototype ATN ground end system with S functionality per ICAO Doc. 9896 Honeywell - MK-II+ Communications Management Unit (CMU) avionics, installed in the Boeing 737 avionics test bench Production Link2000+ ATN CM and CPDLC applications Prototype S Dialog Service per ICAO Doc. 9896 Prototype adaptation of VDLm2 to provide datalink service for network layer - Simulated ATN ground end system with S functionality per ICAO Doc. 9896 SITA - Production VDLm2 ground station (VDLm2 radio + VDL Ground Controller + SITA Front End) modified to recognize and process S messages - Ground-ground connectivity to the prototype ATN ground end system
OSI vs. S Protocol Comparison 3 Focus of 2015 S-over-VDLm2 effort Source: Safety Services Using the Internet Protocol Suite: Benefits, Progress, and Challenges, Digital Avionics Systems Conference, 13-17 Sep 2015.
S-over-VDLm2 Protocol Detail [1/2] 4 ATN Applications (CM, CPDLC) DS App Data App Data S Dialog Service Per Doc. 9896 Per Doc. 9896 Per ISO 9577, an Initial Protocol Identifier (I) with the value 0xCC specifies a frame containing an packet maps to ATNPKT ATNPKT ATNPKT AVLC F A C 1100 1100 Start/End Flag = 0111 1110 VDLm2 Packet ATNPKT FCS Frame Check Control = Un-numbered Information (UI) Frame Sequence Address DL (source = aircraft; destination = CSP broadcast address) UL (source = CSP ground station; destination = aircraft) F
S-over-VDLm2 Protocol Detail [2/2] 5 VDLm2 supports Connection Oriented Protocol used in the existing ATN/OSI framework: - The protocol stack is composed of AVLC/8208/M-SNDCF/CLNP/TP4 complemented by a VME/LME Link Management Layer (XID messages) VDLm2 also support a Connectionless Data Transfer capability using Unnumbered Information (UI) Frames. With the existing ATN/VDLM2 protocol overhead statistics in mind, the use of Datagram as a general principle, and UI frames in particular, was selected as a design objective for S-over-VDLM2. - By modifying AVLC and VME and removing 8208 and VME/LME from the protocol stack, the overhead from XID exchanges, typical AVLC RRs, and 8208 Call Request/Confirms is eliminated Some expected benefits are: - Reduction of overhead in general, and increase of RF efficiency - Receipt of downlink by multiple receivers (thanks to multicast addressing), leading to increased downlink success rate - For uplinks, offers the service provider the option to switch ground stations if the current station is experiencing problems delivering uplinks
S-over-VDLm2 End-to-end Protocol Diagram 6 Avionics VDLm2 Ground System ATN End System CMU VDR Ground Station G-G Router Ground ES ATN Applications ATN Applications S Dialog Service ATNPKT S Dialog Service SN- SME VDR Controller Layer -to- VDLM2 Adapter (IVA) VME AS AVLC Williamsburg Version 3 ARINC 429 VDLm2 Packet AS Williamsburg Version 3 ARINC 429 MAC Interface VDLM2 MAC CSMA PHY D8PSK Datalink Interface VME AVLC L2 VDLM2 MAC CSMA PHY D8PSK L1 L2 L1 L2 L1 L2 L1 Legend: Not Modified Modified New Prior 2014 Effort VDLm2 Datalink
S-over-VDLm2 Test Environment SITA (Montreal, QC) Remote VGS Config Boeing 737 ACARS bench Boeing Integrated Aircraft Systems Laboratory (Seattle, WA) 7 Honeywell ATN/S CMU Internet Fin Antenna Firewall RF Cable Boeing Development ATN/S End System Local LAN VDLM2 SITA Rhode & Schwarz Radio Gateway VHF Rx VHF Tx RF Cable Fin Antenna Boeing Airspace and Operational Efficiency Laboratory (Kent, WA) VGS Controller
S-over-VDLm2 Initial Results 8 ATN Link2000+ CM and CPDLC messages exchanged successfully between CMU avionics and ATN End System via VDLm2 datalink - Laboratory Environment (using an RF attenuator and back-back cable connection between VDR and VGS) - Over-the-Air (using operational VDLm2 frequency) Test cases included: - -over-vdlm2 Service Discovery - CM Logon - CPDLC Start - CPDLC uplink/downlink message exchanges per existing Boeing ATN Link2000+ Test Plan E.g., climb-to-flxxx request, climb-to-and-maintain-flxxx response E.g., ATC heading change request, WILCO response - CPDLC End (ground-initiated end) - CPDLC User-abort (aircraft-initiated termination)
S-over-VDLm2 Future Work 9 Additional Functional Test Cases - Provider Aborts - Message size boundary conditions - Packet loss simulations - Message retransmission mechanisms - Link loss and recovery Performance Measurements and Characterization VGS Enhancements - Test DSP ID configuration (to support flight test) Flight Tests
Points of Contact 10 Gregory Saccone Boeing Research & Technology gregory.t.saccone@boeing.com Questions?? Michael Olive Honeywell Aerospace Advanced Technology mike.olive@honeywell.com Jocelyn Descaillot SITA Information Networking Computing jocelyn.descaillot@sitaonair.aero