1. © 2010 The MITRE Corporation. All rights reserved. AERONAUTICAL COMMUNICATIONS PANEL (ACP) SEVENTEENTH MEETING OF THE WORKING GROUP M Bangkok, Thailand 31 January – 1 February 2011 INFORMATION PAPER Uplink Broadcast SNDCF R. Morgenstern, MITRE

2. © 2010 The MITRE Corporation. All rights reserved. Statement of Problem Point-to-point communications inefficient for some messaging –D-ATIS in the vicinity of the airport –SIGMET –NOTAMs –Aircraft Microphone Check (AMC) AEEC DLK providing broadcast capability for AOA similar to POA network It could be beneficial if solution included ATN interface 2

3. © 2010 The MITRE Corporation. All rights reserved. Broadcast scope 3 All aircraft for a particular Ground Station All aircraft for a cluster of Ground Stations All aircraft of a particular airline A subfleet of a particular airline

4. © 2010 The MITRE Corporation. All rights reserved. Proposed AOA Implementation For AOA ground station addressing, use AP or GL TEIs to address a pre-defined GS or cluster of GSs –E.g., AP AL10, AP IAD1 For AOA addressing, use existing A620/618 AN/FI TEIs to address user fleet/subfleets –E.g., AN AL-B737/FI AL9999, AN BA-XXXX/FI BA9999 No acknowledgement to broadcast messages Duplication detection based on UBI –Generate new UBI for each unique uplink broadcast –Use same UBI for broadcasts over more than 1 GS Only one ACARS uplink sent per GS No uplink ACARS timers (GT1, GT2) Limited to one ACARS block 4

5. © 2010 The MITRE Corporation. All rights reserved. Proposed ATN Implementation Reconstitute CLTP in ICAO Doc 9880, Part III Utilize destination NSAP to identify scope of broadcast –Routers would need to recognize address and realize it might need to multicast to reach all relevant GSs –E.g., ARS = 0xFFFFFFh and accept all LOC/SYS fields Create Broadcast SNDCF to bypass current Mobile 8208 sublayer 5

6. © 2010 The MITRE Corporation. All rights reserved. ATN NSAP Addressing For CLNP addressing, use 0xFFFFFF for ARS –Then LOC can determine the scope of the broadcast –And SYS can determine the specific GS, cluster, airline and/or airline subfleet –SEL = 02h consistent with AsiaPac use to indicate ISO 8602 CLTP ground or air ES 6

7. © 2010 The MITRE Corporation. All rights reserved. Possible LOC/SYS Encoding LOC –0000h reserved –0001h Single GS SYS = unique GS identifier, such as SiteID/RadioID –0002h Airport SYS = 0000h + 4character Airport Code –0003h ACC/TRACON SYS = FFFFFFh + 3character facility code (e.g., ZTL) SYS = sectorID + 3character facility code (e.g, N90) –0004h-FFFEh reserved –FFFFh All GS in ADM region/country SYS = FFFFFFFFFFFFh 7

8. © 2010 The MITRE Corporation. All rights reserved. VDL Mode 2 Interfacing Use UI frame in AVLC Use IPI/EIPI to identify destination applications and bypass 8208 sublayer –AOA continues to use current 0xFFh –ATN: CPDLC (AMC, Advisories), FIS, ADS-C, AOC/FOC ARINC750 radio implementations limited to only 3 addresses stored, so cant use AVLC addressing to isolate sub-sets of a ground stations coverage –AOA has means to provide filtering based on A620/618 address –For ATN, addition of a Broadcast Scope field following the IPI/EIPI is possible –Alternately, just pass all to CLNP and let it filter 8

9. © 2010 The MITRE Corporation. All rights reserved. Status AEEC DLK proceeding with AOA broadcast capability to support AOC needs FAA has action to document need for broadcast capability to RTCA SC214/EUROCAE WG78 –Coordination with WG92 when it is started –LINK2000 already experiencing some D-ATIS- related congestion –AMC application can overload channel for large/busy airports depending on scope of use 9