AT&T Proprietary and Confidential

AT&T Wireless ServicesAviation Communications Division

Air to Ground Data Communications

ePlane Service

WAEA Technical Committee

February 16, 2000

AT&T Proprietary and Confidential

Email Overview

• Internet E-mail– Transport - SMTP– Access

• Proprietary

• POP3

• IMAP4

• E-mail In the Airborne Environment– Transport and Access

– Limitations• Bandwidth• Security• Operational Realities

• ePlane Service in North America - AT&T’s Approach

AT&T Proprietary and Confidential

E-mail Basics - The Big Picture

UAUA

EmailServer

AccessPOP-3IMAP-4

Proprietary

AccessTRANSPORTSMTP

Message FormatFile System Structure

INTERNET

MTAMTA

MTA

MessageStore

Client Server

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Internet E-mail

• Transport – SMTP - Simple Mail Transfer Protocol

– The Internet standard that governs how e-mail messages are sent from site to site.

– Requests For Comment (RFCs) cover:• Message Size Declarations

• Delivery Status Notifications

• Authentication and Error Codes

• Other Rules & Conventions Governing SMTP

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E-mail BasicsAccess - Models

MessageStore

Client

Server

UA

ServerServer

Offline Online Disconnected

Client Client

Updates

Message

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Internet E-mail

• Access– Proprietary access will include POP3 & IMAP4

protocols but may use other messaging technologies besides IP (Eudora, MS Outlook).

– POP3 - Post Office Protocol, provides an off-line access model.

– IMAP4 - Internet Message Access Protocol, provides online & disconnect access model

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PROs and CONsPROTOCOL PRO CON

Proprietary Added features Archiving Hierarchical Address books

Locked into a vendor

POP3 Mature technologyWidely supportedUbiquitous

Off-line modeNo address books

IMAP4 Online modeWidely implementedAllows files syncEfficient messaging

No address books

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E-mail BasicsAccess - Protocols

Protocol Access Mode Function Provided Internet Support

POP-3 Offline Selective download of messages from message store to user’scomputer

All ISP

Selective message delete from message store inboxBasic synchronization between inbox and user’s computer

IMAP-4 Disconnected Hierarchical mail boxes on message store Some ISPAccess several mail boxes simultaneouslyFetch message body and attachments (MIME integration)Fetch message status, header and structureStore, copy and move messages on message store

Online Change message status on message storeSearch mail boxes for particular message headings

Proprietary All three Same as IMAP-4 Requires gatewayAddress books, including mailing listsMessage notification

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Email In the Airborne Environment

• Transport– Always Will Involve an RF Off-Aircraft Link

– Will Require Gateways to Airborne Servers via Satcom, Terrestrial and Gatelink Methodologies

– Will Use Ground-Based IP Network

• Access– Passengers May Use Airborne Telephony, IFE or Other Cabin

Distribution Systems.

– Access Likely to Support “Core” Standard Interfaces (Physical Layer & Logical Layer)

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Limitations of Email In the Airborne Environment

• Bandwidth– Legacy IFE Architectures May Have Limited Throughput– Off-Aircraft Link May Limit Large Attachments (May Not Be a

Strong Limitation with Future Satcom Technologies)

• Security– Corporate “Firewall” Is A Policy Problem - Security Protocols

(IPSEC & SSL) Not Universally Adopted

• Operational Realities– The “Flight Level 100” Problem

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Potential Aircraft Email & Internet Applications

Operations

• Electronic Logbook• Weather• FOQA• Weight Data• Departure Reports• A/C Position• OOOI Reports• 615 Data Loader

– FMS– ACMS

• Fault Reports• Gate Assignment• Engine Data• Crew Scheduling

Cabin Mgmt

• Connecting Gates• Cabin Logbook• Frequent Flyer /

Customer Profile• On-Board Inventory• Systems Info &

Troubleshooting• Departure Reports• Briefings• Customer Service• FA Comm System• Financial Rpts• Cabin Discrepancy

Log (CDL)• Catering Reports• Baggage/Asset

Tracking

Customer Service / IFE

• Transaction Processing• Sports Scores• Connecting Gates• Service Selections• RES Access• Reservations• On-Board Info Service• Real-Time Info Service• Messaging Service• Marketing Tracking• Surveys / Comments• Shopping• Games / Gaming• Advertising• www.com

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AT&T’s Approach

ePLANE Service in North America

AT&T Proprietary and Confidential

AT&T Proprietary and Confidential

Airborne Data Server Architecture

Pilot Station Cabin Mgt Station Maintenance Terminal

On-Board Distribution System

Airborne Data Server (ADS)

Ethernet

IFE Ctrl/Server

Gatelink

Ethernet/Token Ring/RS485ACARS

FMCACMSDFDAU/QARIRS/INS/GPSCMC

Aircraft Systems

CTU/496

Ethernet

BRI/CEPT

A429

A429

CDS

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NATS Network Architecture

Airborne Data Server (ADS)

ADS Gatelink Possibilities

CDPDTether -Ethernet,FDDI

WirelessLAN

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Airline Data Center Concept

X.25/ Frame Relay

Int ernet

ACM Functionality:CommunicationsSecurityData RoutingNetwork Management

802.11POTS LAN

Airborne Communications Manager (ACM)

Gatelink

AT&T Data Hub

Remote Dial Up Access

Legacy SystemsClient Server Environment

ACM

Internal TCP/IP

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Communications Management Functions

Airborne & Ground-Based Capabilities

Stack layers provide the following functionality:• Router API - provides application access to communications channels.

Includes:

– service request validation

– File System interface

– call statistics collection – call detail records (CDR)

• Data Router - provides data routing (application-to-application, both on-board aircraft and off-aircraft). Includes:

– request queuing (by priority and arrival time)

– link selection (terrestrial/satellite/on-board)

– addressing

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Communications Management Functions

Airborne & Ground-Based Capabilities• Convergence - provides protocol conversion, when required. Also provides:

– data encryption/decryption

– data compression (and decompression)

• PAD - provides basic packet service for off-aircraft communications. Includes:

– data fragmentation and re-assembly

– TCP packet assembling and dissembling

– X.25 packet assembling and disassembling

– packet routing

– call control

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Remember…..

• Email Is A Complex & Widely Used Technology– “End-to-End” Solutions Are Preferred - Solutions Must Be

Found For the Airborne and Ground Segments – Standards-Based Solutions Are Recommended– Useful For Airlines Operations As Well As A Passenger

Amenity– Users Must Understand The Limitations– Technology Alone Will Not Provide The Complete Solution