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Airport Surface Network Architecture Definition

Thanh C. Nguyen1, Wesley M. Eddy2, Steven C. Bretmersky3, Fran Lawas-Grodek4, Brenda L. Ellis4

1Analex Corporation/2Verizon Federal Network Systems/3Cleveland State University/4NASA Glenn Research Center Abstract Currently, airport surface communications are fragmented across multiple types of systems. These communication systems for airport operations at most airports today are based dedicated and separate architectures that cannot support system-wide interoperability and information sharing. The requirements placed upon the Communications, Navigation, and Surveillance (CNS) systems in airports are rapidly growing and integration is urgently needed if the future vision of the National Airspace System (NAS) and the Next Generation Air Transportation System (NGATS) 2025 concept are to be realized. To address this and other problems such as airport surface congestion, the Space Based Technologies Project’s Surface ICNS Network Architecture team at NASA Glenn Research Center has assessed airport surface communications requirements, analyzed existing and future surface applications, and defined a set of architecture functions that will help design a scalable, reliable and flexible surface network architecture to meet the current and future needs of airport operations. This paper describes the systems approach or methodology to networking that was employed to assess airport surface communications requirements, analyze applications, and to define the surface network architecture functions as the building blocks or components of the network. The systems approach used for defining these functions is relatively new to networking. It is viewing the surface network, along with its environment (everything that the surface network interacts with or impacts), as a system. Associated with this system are sets of services that are offered by the network to the rest of the system. Therefore, the surface network is considered as part of the larger system (such as the NAS), with interactions and dependencies between the surface network and its users, applications, and devices. The surface network architecture includes components such as addressing/routing, network management, network performance and security. Introduction The current state of most airport surface communication networks is fragmented [1], while the requirements placed upon the Communications, Navigation, and Surveillance (CNS) systems in these airports are rapidly growing and integration is urgently needed if the future vision of the National Airspace System (NAS) [2] and the Next Generation Air Transportation System (NGATS) 2025 concept [3] are to be realized. This problem is compounded by the fact that airport surface communications systems at most airports today are built on legacy circuit-based concepts, rather than modern packetized Internet protocols. The ground-ground communications systems being used by the Federal Aviation Administration (FAA) alone, for instance, are diverse and lack the capability to support systems-wide interoperability and information sharing. To address this and other problems such as airport surface congestion, the Surface ICNS Network Architecture team at NASA Glenn Research Center (GRC) has assessed airport surface communications requirements, analyzed existing and future surface applications, and defined a surface network architecture that is robust and flexible to meet the current and future needs of airport operations. The process of gathering requirements, performing analysis and defining a surface architecture that is robust and flexible to meet the current and future needs of airport operations is very challenging and complex, especially in the post-911 environment. To develop a surface architecture in the context of today’s airport communications and legacy technologies being used at airports in the United States and through the world is enormously difficult. In order to meet the objective of this task, the GRC team selected the System Engineering (SE) approach or systems methodology for assessing surface communications requirements, performing surface applications analysis, and defining a set of architecture functions that will help design and implement any future surface networks.

https://ntrs.nasa.gov/search.jsp?R=20070014985 2020-07-06T19:19:50+00:00Z

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The system engineering approach is presented in the Methodology section of this paper. The rest of this paper presents the results of surface communications requirements assessment, surface applications analysis, and surface network architecture functions and their definitions. Methodology The methodology used for gathering requirements, performing analysis, and defining the Airport Surface Network Architecture is based on the System Engineering (SE) approach. This SE approach has been embraced by the FAA as “proven practices” [4] deemed most appropriate to analysis, planning, design, acquisition, lifecycle support, and management of the Federal Aviation Administrations programs. The systems methodology approach is selected for developing the Airport Surface Network Architecture Definition because the process of gathering requirements, performing analysis and defining a surface architecture that is robust and flexible to meet the current and future needs of the airport operations is enormously complex. In the early phase of Surface Network Architecture Definition (SNAD) development, it was also obvious to the NASA GRC team that the traditional approach to networking for the airport surface would not work, because this traditional approach focuses primarily on capacity planning or bandwidth, while ignoring other components of network resources that are important to the performance of airport operations. Based on [5], the surface network can be defined as a part of the larger system (such as the NAS), and associated with the system are sets of services that are offered by the network to the rest of the system. In general, the flows of information between network analysis, architecture and design are illustrated in Figure 1.

Figure 1: General flows of information between network analysis, architecture and design

Through the above process, the surface communications requirements can be assessed and the existing and future surface applications can be analyzed for communication characteristics. Based on the information derived from requirements assessment and applications analysis, the Surface Network Architecture Definition can be developed. This architecture consists of the major functions or components as the building blocks of any future surface networks that may be designed and implemented to meet the needs of airport operations. Although there

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are other functions such as surface wireless infrastructure, applications services and storage, which can be considered as components of the surface network architecture, this paper will only examine the following common functions: addressing/routing, performance, network management and security. Surface Networks Requirements Analysis The development of an Airport Surface Network that supports legacy communications systems and incorporates new technologies (such as Third Generation Wireless Services and Wireless Local Area Networks) was an important part of the Advanced CNS research effort undertaken by NASA under the Space Based Technologies Project. In order to have a better understanding of the current requirements and future communication needs, NASA decided to contract with the Scientific Applications International Corporation (SAIC) (formerly Trios Associates, Inc.) to examine the current and future airport communications requirements with an eye toward developing a high level set of operational requirements for an Airport Wireless Surface Network (AWSN). The results of this study [6] are summarized below. 1. Airline Operations Communications Systems Requirements In this study, Dallas Fort Worth International Airport (DFW) was selected, because it met the Level 12 traffic study requirement by NASA. DFW has the third largest number of aircraft operations in the United States and it is home to AMR Corporation. AMR Corporation is parent of American Airlines (AA) and American Eagle (AE), the biggest airline in the country. AA and AE comprise 73% of all aircraft operations at DFW. In this study, the remaining airlines’ requirements are extrapolated from the AA’s results (backed up by an interview with Continental Airlines). In addition, AA has a major maintenance base at DFW that added significantly to the communications loading, and AA is also one of the most sophisticated users of communications technology in the passenger airline business. The estimated bandwidth requirements are provided in Table 1.

Airline Estimated Bandwidth Requirements (voice & data) American Airline DFW 45 Mbps All Airlines at DFW 58 Mbps All Airlines at a typical airport 69 Mbps (when difference in total number of airline operations between O’ Hare &

DFW was factored in.)

Table 1: Bandwidth Requirements from SAIC’s Study

Wireless communication for all the airlines mainly involves VHF radios for communications between the airline ramp and the pilot. For other surface activities, trunk radio systems operating in the 400 or 800 MHz ranges are used. At DFW, approximately 70 frequencies are available for airline to pilot communication and around 180 frequencies are used for airline trunk radio systems. 2. FAA Communication Systems DFW was a good choice for examining FAA surface communications because its configuration is unique with two active Air Traffic Control Towers (ATCT): one for air traffic using the east side of the airport and one for the west side. Each tower has its own communication needs and the need to communicate to coordinate when traffic crosses from the east to west or west to east side runways. DFW’s FAA communication systems utilize many diverse media types such as copper, fiber, microwave, and wireless technology and span various FAA buildings around the airport. These systems carry ATC voice, surveillance, weather, and other traffic that are critical to DFW airport operations. These communications systems also have a plenty of redundancy and diversity built in to them as they were designed with criticality and aviation safety in mind.

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DFW is also home to an ASDE-X demonstration system. ASDE-X using ADS-B and Multi-lateration combined with ASDE-3 radar enhances situation awareness for the TRACON, the AA Ramp Control Tower, and the Airport Board. The bandwidth requirement for FAA communications at DFW was estimated from analysis, as follows:

• 23 Mbps is required between the TRACON and the two towers, and • 12 Mbps is required from the TRACON to other FAA facilities on airport • For a busy airport like Chicago O’Hare, these numbers would be extrapolated to 28 Mbps and 15 Mbps

respectively. Spectrum Analysis for FAA systems revealed that around 152 frequencies are being used for ATC voice communication, radio navigation and other services. 3. Airport Operations Communication Systems Because of its size and breadth, DFW provided an opportunity to examine the use of communications by the Airport Board. It should be noted that the U.S. Department of Homeland Security raised the terror alert threat level to Orange during the course of this study. The threat level change made it difficult to capture all DFW Airport Board communications requirements. However, based on the network diagrams and responses to the questionnaires obtained from the airport board, the result for the portion of this study was estimated, as follows:

• The network loading was estimated to be less than 10%. • Since the network runs at 100 Mbps in the Access Layer, any service on the airport board network cannot

have a bandwidth requirement greater than 10 Mbps within the airport. • Communications to the outside world was close to 7 Mbps based on the infrastructure available.

Note that the DFW Airport board actively uses a secure land-mobile radio system that operates in the 800 MHz range with about 32 frequencies as well as a 400 MHz radio system with 6 frequencies. 4. Tenant Communications Systems Trunk radio systems are used by most airport tenants as their main means of communication. These radio systems operate mainly in the 450 MHz band. Radio systems used by various concessionaires and government agencies also operate 30 MHz, 150 MHz and 170 MHz ranges. Passenger needs were captured by assuming that passengers would utilize an 802.11g wireless network. Bandwidth requirements for passengers are assumed to be equal to the maximum provided by the standard. In addition to the FAA and AA/AE, DFW is home to significant United Parcel Service (UPS) and Federal Express (FedEx) cargo shipments. This provided the study with an opportunity to not only look at additional airlines, but also examine the use of wireless networks by two major airport tenants who use wireless networks as part of their day-to-day business. UPS’ LAN in their package sorting facility was assessed to gather the land-line and wireless communications requirements. Their wired LAN consists of a single LAN with Cisco switches/routers interconnected by fiber and copper. The network does not have outside access to any other entities on the airport; instead a phone system is used for this function. A fractional T-1 is used for off airport access to their corporate head-quarters. An 802.11b wireless LAN system is used for scanning packages from loading gates.

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5. Existing Systems Assessment Specific interface characteristics, protocols, data rates of the communications systems used by airlines were collected. Databases with FAA and airport tenant information are provided with the final report [6]. A summary of the analysis of the data for all stakeholders is included in Section 5 of that report. 6. Services Description and Criticality Evaluation From the document search and on-site interviews the SAIC team was able to determine the criticality of the applications that might traverse the AWSN. The following is a summary of this evaluation:

• For airline operations, any service interruptions that affect schedules are critical. • For FAA, all communications, navigation, and surveillance systems are critical. • Hazardous weather systems are also considered critical. • For the airport board, police, fire, and emergency as well as other airport operations in the surface

movement area are considered critical. 7. Current Wireless Systems To get a better understanding of the frequencies in and around DFW, SAIC obtained the output of the National Telecommunications and Information Administration (NTIA) frequency database for an 8 mile radius with origin being at the center of the DFW area. The Aeronautical Frequency Committee (AFC), operated by ARINC for the industry, provided the Federal Communications Commission (FCC) equivalent that included the ARINC used frequencies at DFW. These outputs were combined into a single database, which contains approximately 20,000 frequency assignment records, with a minimum of overlap (approximately about 500 records). When scaled down to address only the frequencies used inside the fence line of the airport, there are approximately 4800 assignments. With the above information gathered, SAIC was able to determine the communications traffic loading requirements for the AWSN based on the current copper, fiber and microwave systems. 8. Proposed Set of Requirements The main result of this study is a set of proposed requirements including technical, performance, security, system safety and policy aspects whether the AWSN is used for wireless, wire-line replacement, aircraft to controller voice, or data link systems. Below is a subset of the performance requirements:

• The AWSN, for Aircraft to Ground, communication shall meet the required communication technical performance of 770 ms 95% of the time and the continuity, availability and integrity numbers as specified in [7].

• The AWSN shall have the following minimum data rates for each segment of the user community listed in Table 2.

• The AWSN shall be expandable, at a minimum, to 200% of its minimum data and voice capacity requirements to support growth.

• The AWSN shall be capable of supporting end-to-end services that have 0.99999 availability with a six second mean-time-to-restore in accordance with FAA Order 6000.36 and the NAS-SR-1000.

• The AWSN latency, when used as a wire-line replacement to an ATC voice and data communication site, shall not exceed 25 ms in one direction.

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Stakeholder Minimum Data Rate

FAA 28 Mbps (TRACON to Tower); 15 Mbps (TRACON or ATCT to RTRs, NAVAIDS, ASR-9 Radar, DBRITE, Weather Sensors, etc.)

Airlines 69 Mbps Airport 7 Mbps for data

Passengers 54 Mbps (based on 802.11g)

Table 2: Estimated Data Rate for User Community Surface Application Requirements Analysis Applications requirements are generally requirements that are determined from application information, experience, or testing [5]. Application information that has been collected and analyzed for each of the current and future surface applications is necessary to understand the requirements imposed by applications upon the communications systems. These major applications were categorized, as follows:

• Air Traffic Management (ATM) • Aeronautical Operational Control (AOC) • Airline Administrative Communications (AAC) • Airport Operation Communications

The current and future applications for ATM and AOC are listed in Table 3 through Table 6. An example of current Predeparture Clearance (PDC) communications characteristics are shown in Table 7. For more information about other communications characteristics please see [8].

Current ATM Applications Description Pilot-Controller Communications Pilot-Controller Communications includes Predeparture Clearance (PDC), Taxi

Clearance and Oceanic Clearance. Context Management (CM) CM applications initiates and maintains data link connection between an aircraft

and ground station Airport Terminal Information Service (ATIS)

ATIS is the continuous broadcast of recorded non-control information in selected high activity terminal areas.

Notice to Airmen Time-critical aeronautical information disseminated via the National Notice to Airmen (NOTAM) System.

Cockpit Voice This is an ATC-related application. Remote Transmitter/Receivers (RTR)

RTRs are responsible for carrying critical ATC radio traffic between ATCT/TRACON and pilots.

Tower Data Link System (TDLS) TDLS is a user-friendly computer interface to support multiple concurrent airport air traffic control tower applications on one platform.

METAR International Aviation Routine Weather Report TWIP Terminal Weather Information to Pilots MDCRS Meteorological Data Collection & Report System, which is an ATC advisory

service. LLWAS Low-Level Wind Shear Alert System, which is used to measure wind speed and

direction at remote sites around airport terminal. AWOS Automated Weather Observing System ASOS Automated Surface Observing System ITWS Integrated Terminal Weather System RVR Runway Visual Range provides real-time RVR data to FAA facilities and air

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carriers. Surveillance This includes Airport Surveillance Radar (ASR-9), Airport Surface Detection

Equipment (ASDE-X/ASDE-3), Surface Movement Advisor, Airport Movement Area Safety System (AMASS) and Digital Bright Radar Indicator Tower Equipment (DBRITE).

NAVAIDS Airfield Navigational Aids (NAVAIDS) are small sensors located around the airport that give aircraft information for landing and takeoff.

ILS Instrument Landing System helps aircraft land safely on a runway and it consists of a Localizer, Glide Slope, and Markers.

MLS Microwave Landing System Distance Measuring Equipment Provides distance separation measurement between an aircraft and the ground

unit. VOR VHF Omnidirectional Ranging provides magnetic bearing information for long

range navigation (up to 175 NM). Non Directional Beacon Provides pilots with indications of bearing to ground transmitting station. TACAN TACtical Air Navigation (TACAN) is a military long range navigational aid sited

with or instead of a VOR. LORAN-C Long Range Navigation C is a civil marine radio navigation system used in

coastal waters for up 1200 miles. WAAS Wide Area Augmentation System is a safety-critical navigation system being

developed by FAA. LAAS Local Area Augmentation System is a safety-critical navigation system intended

to complement WAAS.

Table 3: Current ATM Applications and Descriptions

Future ATM Applications Description CPDLC Services Controller-Pilot Data Link Communications (CPDLC) services replace voice

communications for clearances between controller and aircraft with digital messages.

ATC Clearance (ACL) ACL service provides the mechanism to request and receive clearances, instructions, and notifications.

Departure Clearance (DCL) DCL service provides automated assistance for the request and delivery of departure information & clearance.

ATC Communication Management (ACM)

ACM service provides automated assistance to pilots and controllers for conducting transfer of all ATC communications (both voice and data).

Data Link Taxi Clearance (D-TAXI) D-TAXI service provides automated assistance to controllers and pilots to perform communication exchanges during ground movement operations.

Common Trajectory Coordination (CONTAC)

COTRAC service provides a mechanism to establish and agree trajectory contracts between pilots and controllers in real-time.

ATC Microphone Check (AMC) AMC service provides a one-way uplink alternative to voice communications for contacting aircraft via data link, in the event that a “stuck microphone” blocks the voice channel.

Automatic Downlink of Airborne Parameters (ADAP) Services

ADAP services include Flight Plan Consistency (FLIPCY), Flight Path Intent (FLIPINT), Pilot Preferences Downlink (PPD) and System Access Parameters (SAP).

D-FIS Data Link Flight Information Services, including D-OTIS, D-RVR, D-SIGMET, D-ATIS and D-FLUP.

D-OTIS Data Link Operational Terminal Information Service. D-RVR Data Link Runway Visual Range D-SIGMET Data Link Significant Meteorological Information D-ATIS Data Link Automatic Terminal Information Service

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D-FLUP Data Link Flight Update Service DLL Data Link Logon is the Data Initiation Capability service that allows automatic

logon and contact with the system. D-SIG Data Link Surface Information and Guidance service delivers current, static

graphical airport map to flight crew. Traffic and Surveillance Services These services include Automatic Dependent Surveillance – Broadcast (ADS-B)

and Traffic Information Service – Broadcast (TIS-B).

Table 4: Future ATM Applications and Descriptions

Current AOC Applications Description Cockpit Voice Operation Flight crew-to-company voice services and flight crew-to-flight crew voice

communications. Airport/Ramp Area Operations Support services that interact with pilot, cabinet crew and aircraft in order to turn

the aircraft around at the gate. Out Off On In (OOOI) Movement service messages, including Out, Off, On, In report data that is

automatically routed to the AOC Movement Control System. NOTAM Notice to Airmen Request/Notice to Airmen service delivers ATIS data that

includes any immediate NOTAMs available. Weather Request/Weather Weather Request includes flight crew request for airport weather. Weather reports

include METARs and TAFs. Position Report Automatic downlink of position during climb, cruise and descent positions of

flight. Flight Status Reporting flight status (such as malfunction reports to maintenance). Engine Performance Reports Reporting Aircraft Condition Monitoring System (engine and systems) via

automatic downlink and on request. Flight Plan Transfer Providing the operators with the ability to request and receive the AOC-developed

flight plan for comparison to that assigned by ATC and for loading into avionics. Loadsheet Request/Transfer Load sheet and cargo information uplinked to cockpit automatically or upon

request. Flight Log Transfer Delivering next flight assignment, estimated time of departure & gate information. Gate and Connecting Flight Status Manual and automatic uplink of connecting flights, ETD, and gate before landing.

Table 5: Current AOC Applications and Descriptions

Future AOC Applications Description Graphical Weather Information Weather information sent to the aircraft in the form that is suitable for graphical

displays in the cockpit (e.g., vector graphics). Online Technical Trouble Shooting Allowing airline ground maintenance staff to request information from on-board

systems so that a diagnosis of problems can be performed away from the aircraft’s base.

Real Time Weather Report Automatic weather reporting in real-time. Technical Log Book Update Allowing the flight crew to complete the aircraft’s technical log electronically and

send this log to maintenance base. Cabin Log Book Transfer Allowing the cabin crew to complete the aircraft’s cabin equipment log

electronically and send this log to the AOC. Online Documentation Transfer Replacing many of the paper documents currently being required to be carried in

the cockpit (e.g., Aircraft Manual and AICs). Software Loading Allowing new versions of software to be uploaded the aircraft systems.

Table 6: Future AOC Applications and Descriptions

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Parameter Value

Information Unit Size (uplink/downlink) ( 1800 / 304 ) bits Occurrence (uplink/downlink) (1.25 / 2.25) msg/flt Required Response or Delay Time 5 min Estimated bandwidth required 1,200 bps Precedence None Integrity Required (Undetected Error Rate) < 10-6 Availability 95 - 98% Encryption No Authentication No Communication links used VHF voice / ACARS Source/Destination Cockpit/ATC

Table 7: An Example of PDC Communications Characteristics The third category is the Airline Administrative Communication (AAC), which pertains to the airline to aircraft messaging applications that are related to the routine administration of what can be defined as cabinet crew operations. There are presently only a few data link messages that are within this category and may by FCC licensing be transmitted on the current air-to ground data link. The following list includes such applications:

• Airlines Gate Connection Information • Medical Assistance Requests • Crew Schedule and Lodging Information • Miscellaneous Free Text Crew Information • Passenger lists • Aircraft Catering

• Baggage handling • Aircraft fueling • Lost and found • In-flight Assistance • Duty Free Sales, i.e. purchases in the air,

e.g. liquor, headphones In some cases, these applications are performed using the airline company voice channels as described under AOC. The data communications requirements are identical to those stated for AOC. The communications characteristics of AAC are shown in Table 8.

Parameter Value Information Unit Size Messages < 256 bytes. Multi-block messages < 3,000 bytes Occurrence 20 - 30 messages per flight segment Required Response or Delay Time < 1 min delivery. Reject messages > 5 min old Estimated bandwidth required VHF system - 1,200 bps. Satellite system - approx. 10,000 bps Precedence None Integrity Required (Undetected Error Rate) 10-6 to 10-7 Availability 95 – 98% Encryption No Authentication No Communication links used Source/Destination

Table 8: AAC Communications Characteristics Finally, some Airport Operation Communications are expected to make use of the surface network. Some of the anticipated users include the Port Authority, Department of Public Safety, and the county in airport vehicles. Information for the applications for these users could not be obtained.

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Surface Architectural Models and Components In developing the architecture for the airport surface network that is scalable, reliable and flexible to support the current and future airport operations, the NASA GRC team faced with a difficult decision: which architectural model is right for the surface network? Generally, there are three types of architectural models that can be applied to any surface networks: topological, flow-based, and functional. One or all of these three types of models can be included in the Surface Reference Architecture. Topological models are based on a geographical configuration; flow-based models are based on data traffic flows; and functional models focus on one or more functions or features planned for the network. After a careful evaluation of communications systems being used today at most airports and the potential enhancement that can be made in the future for airport operations, the team decided instead to focus on the component architectures of the surface network. Component architecture is a description of how and where each function of a network is applied within that network. [5]. This is important because defining the building blocks of architecture as network functions instead of physical entities is essential to the success of the Surface Network Architecture. In order to successfully develop the surface network that will meet the operational requirements of any airports, the following major functions or components have to be defined: addressing/routing, network management, performance, and security. A brief description of each of these functions, its capability and mechanisms are shown in Table 9. For more information about these functions please see [8].

Function Capability Mechanisms Addressing/ Routing

Providing robust and flexible connectivity between devices. Network devices such as IP routers, switches, SONET hubs, modems, wireless access points, firewalls, servers and end-user stations. And, connected to the core surface network, there are many diverse pieces of hardware, such as ASR-9 radar units, RTR radios, Localizers, Glide Slopes, Markers, ASDE-X, and others.

1) Addressing mechanisms for both IPv4 and IP6 were evaluated for surface networks. Aggregation versus Classless Inter-Domain Routing (CIDR) and other considerations, including Dual Stack, 6to4 gateway, Private Addressing, Network Address Translation (NAT), Multicast, and Mobility. 2) Routing mechanisms include Routing Flows Establishment, Routing Boundaries and Routing Flows Manipulation.

Network Management

Providing network monitoring, configuration and troubleshooting for the surface network. A survey of COTS network monitoring and configuration software products were conducted. These software tools can potentially be integrated into the surface networks for monitoring and configuring.

Network management mechanisms include network management protocols (such as SNMPv3, CMIP, or CMOT), devices management and network configuration.

Performance Providing network resources to support network performance requirements (capacity, delay, and RMA).

QoS, SLAs, and policies. QoS mechanisms include, for example, Error Detection/Correction, Adaptive Modulations, Automatic Repeat Request, Prioritization, Scheduling, Traffic Shaping/Policing, IntServ and DiffServ.

Security Protecting surface networks and services from unauthorized access, modification, destruction, or disclosure to ensure the integrity, confidentiality, and availability of these networks and system resources and data.

Security mechanisms include firewalls, security policies and procedures, filters and access control lists. These cover, for instance, physical security and awareness, protocol and application security, authentication, encryption and decryption, network perimeter and remote security.

Table 9: Functions as Building Blocks of a Surface Network Architecture

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Summary and Conclusions This paper has summarized the results of recent NASA GRC studies regarding surface communications requirements, surface applications and architecture functions that will help design a robust and flexible network architecture to meet the current and future needs of airport operations. Based on the results of the surface network requirements assessment conducted by SAIC for NASA, we have been able to gain a better understanding of the current state of surface communications at most airports today in the United States. There is not enough information about stakeholder’s expectations and needs, applications, devices and data traffic flows derived from these requirements to form the foundation upon which a scalable, reliable and flexible surface network architecture can be developed. This study, however, is a good starting point for a more comprehensive surface CNS network requirements development and analysis in future studies in which modeling and simulation of surface users, applications and network behavior may be included. Although comprehensive data have been collected for existing and future surface applications, interoperability among these applications cannot be discerned in the context of today’s airport communications or in any future trends being set by aviation and policy-making authorities. However, it is most likely that internetworking will use IPv6 as the network layer architecture standard in the future and transitioning to this standard will help achieve this interoperability, not only among surface applications but all aeronautical related applications. Encouraging news is that the FAA's current efforts involving the packet-based FAA Telecommunication Infrastructure (FTI) network and the deployment and transition to System-Wide Information Management indicate that network-centric operation is a major component of the future system. The airport surface is a crucial part of these efforts and activities, and this document is a step towards building the required networking services in this domain. Reference

[1] Rafael D. Apaza, “Wireless Communications for Airport Surface: An Evaluation of Candidate Wireless Technologies,” 10th Ka and Broadband Communications Conference, September 2004.

[2] Blueprint for NAS Modernization, 2002 Update, the Federal Aviation Administration’s (FAA) Overview of the Evolving National Airspace System Architecture, October 2002.

[3] Next Generation Air Transportation System Integrated Plan, Joint Planning and Development Office (JPDO), December 2004.

[4] NAS System Engineering Manual, FAA ATO Operations Planning, Version 3.0, 2004. [5] Network Analysis, Architecture, and Design, Second Edition, by J. D. McCabe, Morgan Kaufmann

Publishers, 2003. [6] Task Order 2 Surface CNS Network Requirements – ACAST Final Report, SAIC Aviation Science

Operations, SEAS Business Unit (Formerly Trios Associates, Inc.), September, 2004. [7] RTCA DO-284, Appendix C1, Section 5, Change 1, Table 5-2.1, January 2003. [8] Surface Network Architecture Definition, Draft Version 2.6a, NASA Glenn Research Center, December

2005.

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&

info

rmat

ion

shar

ing

●Su

rfac

e co

nges

tion

is a

rea

l pro

blem

●N

eed

accu

rate

and

com

plet

e in

form

atio

n on

traf

fic

loca

tions

& in

tent

ions

, esp

ecia

lly a

t nig

ht a

nd lo

w-

visi

bilit

y fo

r m

anag

ing

surf

ace

traf

fic m

ovem

ent

●N

eed

a sy

stem

atic

app

roac

h to

def

inin

g a

surf

ace

ICN

S ne

twor

k ar

chite

ctur

e th

at is

rob

ust a

nd fl

exib

le to

mee

t cu

rren

t and

futu

re n

eeds

of a

irpo

rt o

pera

tions

, esp

ecia

lly

post

-911

env

iron

men

t.

5

App

roac

h●

Tra

ditio

nal a

ppro

ach

to

netw

orki

ng w

ould

not

wor

k be

caus

e:–

Proc

ess:

too

com

plex

–R

esul

ts: r

arel

y re

prod

ucib

le a

nd

defe

nsib

le–

Focu

sing

on

capa

city

pla

nnin

g or

ba

ndw

idth

, whi

le ig

nori

ng o

ther

co

mpo

nent

s of n

etw

ork

reso

urce

s●

Syst

em E

ngin

eeri

ng (S

E)

App

roac

h:–

Em

brac

ed b

y FA

A a

s “pr

oven

pr

actic

es”

–A

dopt

ed b

y IN

CO

SE●

Syst

em m

etho

dolo

gy, a

s app

lied

to

netw

orki

ng:

–B

uild

ing

bloc

ks a

s fun

ctio

ns o

f ar

chite

ctur

e, in

stea

d of

phy

sica

l en

titie

s–

Net

wor

k as

par

t of l

arge

r sy

stem

(suc

h as

the

NA

S)

Info

rmat

ion

flow

bet

wee

n n

etw

ork

anal

ysis

, arc

hite

ctur

e an

d de

sign

6

Surf

ace

Net

wor

k R

equi

rem

ents

Ass

essm

ent

●N

ASA

con

trac

ted

SAIC

to g

athe

r su

rfac

e ne

twor

k re

quir

emen

ts a

nd th

e re

sults

kno

wn

as “

Tri

os R

epor

t”1.

Air

line

oper

atio

ns c

omm

unic

atio

ns sy

stem

s req

uire

men

ts2.

FAA

com

mun

icat

ion

syst

ems

3.A

irpo

rt o

pera

tions

com

mun

icat

ions

syst

ems

4.T

enan

t com

mun

icat

ions

syst

ems

5.Se

rvic

es d

escr

iptio

n an

d cr

itica

lity

eval

uatio

n6.

Cur

rent

wir

eles

s sys

tem

s7.

Prop

osed

set o

f req

uire

men

ts

7

1. A

irlin

e O

pera

tions

Com

mun

icat

ions

Sys

tem

s Req

uire

men

ts

●D

FW se

lect

ed fo

r th

is st

udy

beca

use:

–L

evel

12

traf

fic r

equi

rem

ents

by

NA

SA w

as m

et–

Thi

rd la

rges

t num

ber

of a

ircr

aft o

pera

tion

in th

e U

S–

Hom

e to

AM

R C

orp,

par

ent o

f Am

eric

an A

irlin

es (A

A) a

nd

Am

eric

an E

agle

(AE

): la

rges

t air

line

in th

e co

untr

y; 7

3% o

f all

airc

raft

at D

FW–

Est

imat

ed b

andw

idth

req

uire

men

ts (v

oice

& d

ata)

obt

aine

d:•

AA

at D

FW:

45 M

bps

•A

ll A

irlin

es a

t DFW

:58

Mbp

s•

All

Air

lines

at a

typi

cal a

irpo

rt:

69 M

bps (

whe

n di

ffer

ence

in to

tal n

umbe

r of

air

line

oper

atio

ns b

etw

een

O’H

are

& D

FW w

as fa

ctor

ed in

)–

Wir

eles

s com

mun

icat

ion

for

all t

he a

irlin

es m

ainl

y in

volv

es V

HF

radi

os fo

r co

mm

unic

atio

ns b

etw

een

the

airl

ine

ram

p an

d th

e pi

lot.

Fo

r ot

her

surf

ace

activ

ities

, tru

nk r

adio

syst

ems o

pera

ting

in th

e 40

0 or

800

MH

z ra

nges

are

use

d. A

t DFW

, app

roxi

mat

ely

70

freq

uenc

ies a

re a

vaila

ble

for

airl

ine

to p

ilot c

omm

unic

atio

n an

dar

ound

180

freq

uenc

ies a

re u

sed

for

airl

ine

trun

k ra

dio

syst

ems.

8

2. F

AA

Com

mun

icat

ions

Sys

tem

s

●D

FW w

as a

goo

d lo

catio

n fo

r st

udyi

ng F

AA

surf

ace

com

mun

icat

ions

: –

Tw

o ac

tive

Air

Tra

ffic

Con

trol

Tow

ers (

AT

CT

)–

Div

erse

med

ia ty

pes (

copp

er, f

iber

, mic

row

ave

and

wir

eles

s te

chno

logy

span

ning

var

ious

FA

A b

uild

ings

)–

Hom

e to

an

ASD

E-X

dem

onst

ratio

n sy

stem

(usi

ng A

DS-

B &

Mul

ti-la

tera

tion

com

bine

d w

ith A

SDE

-3 r

adar

)–

Est

imat

ed b

andw

idth

req

uire

men

ts fo

r FA

A c

omm

unic

atio

ns a

t D

FW:

•23

Mbp

s is r

equi

red

betw

een

the

TR

AC

ON

and

the

two

tow

ers,

and

•12

Mbp

s is r

equi

red

from

the

TR

AC

ON

to o

ther

FA

A fa

cilit

ies o

n ai

rpor

t•

For

a bu

sy a

irpo

rt li

ke C

hica

go O

’Har

e, th

ese

num

bers

wou

ld b

e ex

trap

olat

ed

to 2

8 M

bps a

nd 1

5 M

bps r

espe

ctiv

ely.

–Sp

ectr

um A

naly

sis f

or F

AA

syst

ems r

evea

led

that

aro

und

152

freq

uenc

ies a

re b

eing

use

d fo

r A

TC

voi

ce c

omm

unic

atio

n, r

adio

na

viga

tion

and

othe

r se

rvic

es.

9

FAA

Com

mun

icat

ions

at D

FW

Sour

ce: P

rovi

ded

by S

AIC

to N

ASA

10

3. A

irpo

rt O

pera

tions

Com

mun

icat

ions

Sys

tem

s

●D

urin

g th

e co

urse

of t

his S

AIC

stud

y, U

.S. D

HC

rai

sed

the

terr

or a

lert

thre

at to

“O

rang

e”, m

akin

g it

diff

icul

t to

capt

ure

all D

FW A

irpo

rt B

oard

(AB

) com

mun

icat

ions

req

s.●

How

ever

, bas

ed o

n ne

twor

k di

agra

ms a

nd r

espo

nses

to

ques

tionn

aire

s fro

m A

B, t

he S

AIC

team

was

abl

e to

lear

n th

e fo

llow

ing:

–T

he n

etw

ork

load

ing

was

est

imat

ed to

be

less

than

10%

. –

Sinc

e th

e ne

twor

k ru

ns a

t 100

Mbp

s in

the

Acc

ess L

ayer

, any

se

rvic

e on

the

airp

ort b

oard

net

wor

k ca

nnot

hav

e a

band

wid

th

requ

irem

ent g

reat

er th

an 1

0 M

bps w

ithin

the

airp

ort.

–C

omm

unic

atio

ns to

the

outs

ide

wor

ld w

as c

lose

to 7

Mbp

s bas

ed

on th

e in

fras

truc

ture

ava

ilabl

e.N

ote:

DFW

Air

port

boa

rd a

ctiv

ely

uses

a se

cure

land

-mob

ile r

adio

sy

stem

that

ope

rate

s in

the

800

MH

z ra

nge

with

abo

ut 3

2 fr

eque

ncie

s as w

ell a

s a 4

00 M

Hz

radi

o sy

stem

with

6 fr

eque

ncie

s.

11

4. T

enan

t Com

mun

icat

ions

Sys

tem

s

●M

ain

mea

ns o

f com

mun

icat

ion

by m

ost a

irpo

rt te

nant

s:

Tru

nk r

adio

syst

ems o

pera

ting

in 4

50 M

Hz

band

●G

over

nmen

t age

ncie

s & v

ario

us c

once

ssio

nair

es u

se r

adio

sy

stem

s ope

ratin

g in

30

MH

z, 1

50 M

Hz

and

170

MH

z ra

nges

.●

Pass

enge

rs: 8

02.1

1g w

irel

ess n

etw

ork

●In

add

ition

to F

AA

and

AA

/AE

, DFW

is h

ome

to si

gnifi

cant

U

PS &

Fed

ex c

argo

ship

men

ts.

UPS

& F

edex

use

wir

eles

s ne

twor

ks a

s par

t of t

heir

day

-to-

day

busi

ness

.

12

5. S

ervi

ces D

escr

iptio

n &

Cri

tical

ity E

valu

atio

n

●Se

rvic

es d

escr

iptio

n &

cri

tical

ity o

f app

licat

ions

are

de

term

ined

, as f

ollo

ws:

–Fo

r ai

rlin

e op

erat

ions

, any

serv

ice

inte

rrup

tions

that

aff

ect

sche

dule

s are

cri

tical

.–

For

FAA

, all

com

mun

icat

ions

, nav

igat

ion,

and

surv

eilla

nce

syst

ems a

re c

ritic

al.

–H

azar

dous

wea

ther

syst

ems a

re a

lso

cons

ider

ed c

ritic

al.

–Fo

r th

e ai

rpor

t boa

rd, p

olic

e, fi

re, a

nd e

mer

genc

y as

wel

l as

othe

r ai

rpor

t ope

ratio

ns in

the

surf

ace

mov

emen

t are

a ar

e co

nsid

ered

cri

tical

.

13

6. C

urre

nt S

urfa

ce W

irel

ess S

yste

ms

●O

utpu

ts o

f fre

quen

cies

in &

aro

und

DFW

obt

aine

d fr

om

Nat

iona

l Tel

ecom

mun

icat

ion

& In

form

atio

n A

dmin

istr

atio

n (N

TIA

) & A

eron

autic

al F

requ

ency

C

omm

ittee

(AFC

) ope

rate

d by

AR

INC

, as f

ollo

ws:

–8

mile

rad

ius,

cent

er a

t DFW

: tot

al o

f 20,

000

freq

uenc

y as

sign

men

t rec

ords

–In

side

DFW

air

port

’s fe

nce

line:

4, 8

00 a

ssig

nmen

ts.

–L

arge

st u

sers

at D

FW: N

EX

TE

L w

ith 2

,500

ass

ignm

ents

in

800

MH

z ra

nge

–U

sers

: ran

ging

from

Mac

Don

ald’

s to

FAA

to N

EX

TE

L to

A

RIN

C.

–Fo

r pa

ssen

ger

Inte

rnet

& V

PN a

cces

s, 80

2.11

b cu

rren

tly

depl

oyed

at D

FW te

rmin

al a

rea

14

7. P

ropo

sed

Set o

f R

equi

rem

ents

●T

he m

ain

resu

lt of

req

uire

men

ts a

sses

smen

t is a

set o

f pro

pose

d re

quir

emen

ts fo

r A

WSN

, as f

ollo

ws:

–

The

AW

SN, f

or A

ircr

aft t

o G

roun

d, c

omm

unic

atio

n sh

all m

eet

the

requ

ired

com

mun

icat

ion

tech

nica

l per

form

ance

of 7

70 m

s 95

% o

f the

tim

e an

d th

e co

ntin

uity

, ava

ilabi

lity

and

inte

grity

nu

mbe

rs a

s spe

cifie

d in

RT

CA

DO

-284

.–

The

AW

SN sh

all h

ave

the

follo

win

g m

inim

um d

ata

rate

s for

eac

h se

gmen

t of t

he u

ser

com

mun

ity li

sted

in th

e ne

xt sl

ide.

–T

he A

WSN

shal

l be

expa

ndab

le, a

t a m

inim

um, t

o 20

0% o

f its

m

inim

um d

ata

and

voic

e ca

paci

ty r

equi

rem

ents

to su

ppor

t gro

wth

(N

ew te

chno

logy

may

be

requ

ired

to m

eet t

his g

row

th!!

!)–

The

AW

SN sh

all b

e ca

pabl

e of

supp

ortin

g en

d-to

-end

serv

ices

that

ha

ve 0

.999

99 a

vaila

bilit

y w

ith a

six

seco

nd m

ean-

time-

to-r

esto

re in

ac

cord

ance

with

FA

A O

rder

600

0.36

and

the

NA

S-SR

-100

0.–

The

AW

SN la

tenc

y, w

hen

used

as a

wir

e-lin

e re

plac

emen

t to

an

AT

C v

oice

and

dat

a co

mm

unic

atio

n si

te, s

hall

not e

xcee

d 25

ms i

non

e di

rect

ion.

15

Est

imat

ed D

ata

Rat

e fo

r U

ser

Com

mun

ity

54 M

bps (

base

d on

802

.11g

)Pa

ssen

gers

7 M

bps f

or d

ata

Airp

ort

69 M

bps

Airl

ines

28 M

bps (

TRA

CO

N to

Tow

er);

15 M

bps (

TRA

CO

N o

r A

TCT

to R

TRs,

NA

VA

IDS,

ASR

-9 R

adar

, DB

RIT

E,

Wea

ther

Sen

sors

, etc

.)

FAA

Min

imum

Dat

a R

ate

Stak

ehol

der

16

Wir

eles

s Sur

face

Net

wor

k

Sour

ce: P

rovi

ded

by R

afae

l D. A

paza

of F

AA

AT

O to

NA

SA

17

Surf

ace

App

licat

ion

Req

uire

men

ts A

naly

sis

●M

ajor

surf

ace

appl

icat

ions

col

lect

ed a

nd

cate

gori

zed,

as f

ollo

ws:

1.A

ir T

raff

ic M

anag

emen

t (A

TM

)2.

Aer

onau

tical

Ope

ratio

nal C

ontr

ol (A

OC

)3.

Air

line

Adm

inis

trat

ive

Com

mun

icat

ions

(AA

C)

4.A

irpo

rt O

pera

tion

Com

mun

icat

ions

18

Cur

rent

AT

M A

pplic

atio

ns (1

/2)

Run

way

Vis

ual R

ange

pro

vide

s rea

l-tim

e R

VR

dat

a to

FA

A fa

cilit

ies a

nd a

ir c

arri

ers.

RV

R

Inte

grat

ed T

erm

inal

Wea

ther

Sys

tem

ITW

S

Aut

omat

ed S

urfa

ce O

bser

ving

Sys

tem

ASO

S

Aut

omat

ed W

eath

er O

bser

ving

Sys

tem

AW

OS

Low

-Lev

el W

ind

Shea

r A

lert

Sys

tem

, whi

ch is

use

d to

mea

sure

win

d sp

eed

and

dire

ctio

n at

re

mot

e si

tes a

roun

d ai

rpor

t ter

min

al.

LL

WA

S

Met

eoro

logi

cal D

ata

Col

lect

ion

& R

epor

t Sys

tem

, whi

ch is

an

AT

C a

dvis

ory

serv

ice.

MD

CR

S

Ter

min

al W

eath

er In

form

atio

n to

Pilo

tsT

WIP

Inte

rnat

iona

l Avi

atio

n R

outin

e W

eath

er R

epor

tM

ET

AR

TD

LS

is a

use

r-fr

iend

ly c

ompu

ter

inte

rfac

e to

supp

ort m

ultip

le c

oncu

rren

t air

port

air

traf

fic

cont

rol t

ower

app

licat

ions

on

one

plat

form

.T

ower

Dat

a L

ink

Syst

em (T

DL

S)

RT

Rs a

re r

espo

nsib

le fo

r ca

rryi

ng c

ritic

al A

TC

rad

io tr

affic

bet

wee

n A

TC

T/T

RA

CO

N a

nd

pilo

ts.

Rem

ote

Tra

nsm

itter

/Rec

eive

rs (R

TR

)

Thi

s is a

n A

TC

-rel

ated

app

licat

ion.

Coc

kpit

Voi

ce

Tim

e-cr

itica

l aer

onau

tical

info

rmat

ion

diss

emin

ated

via

the

Nat

iona

l Not

ice

to A

irm

en

(NO

TA

M) S

yste

m.

Not

ice

to A

irm

en

AT

IS is

the

cont

inuo

us b

road

cast

of r

ecor

ded

non-

cont

rol i

nfor

mat

ion

in se

lect

ed h

igh

activ

ity te

rmin

al a

reas

.A

irpo

rt T

erm

inal

Info

rmat

ion

Serv

ice

(AT

IS)

CM

app

licat

ions

initi

ates

and

mai

ntai

ns d

ata

link

conn

ectio

n be

twee

n an

air

craf

t and

gro

und

stat

ion

Con

text

Man

agem

ent (

CM

)

Pilo

t-C

ontr

olle

r C

omm

unic

atio

ns in

clud

es P

rede

part

ure

Cle

aran

ce (P

DC

),T

axi C

lear

ance

an

d O

cean

ic C

lear

ance

.Pi

lot-

Con

trol

ler

Com

mun

icat

ions

Des

crip

tion

Cur

rent

AT

M A

pplic

atio

ns

19

Cur

rent

AT

M A

pplic

atio

ns (2

/2)

Loc

al A

rea

Aug

men

tatio

n Sy

stem

is a

safe

ty-c

ritic

al n

avig

atio

n sy

stem

inte

nded

to

com

plem

ent W

AA

S.L

AA

S

Wid

e A

rea

Aug

men

tatio

n Sy

stem

is a

safe

ty-c

ritic

al n

avig

atio

n sy

stem

bei

ng

deve

lope

d by

FA

A.

WA

AS

Lon

g R

ange

Nav

igat

ion

C is

a c

ivil

mar

ine

radi

o na

viga

tion

syst

em u

sed

in c

oast

al

wat

ers f

or u

p 12

00 m

iles.

LO

RA

N-C

TA

Ctic

al A

ir N

avig

atio

n (T

AC

AN

) is a

mili

tary

long

ran

ge n

avig

atio

nal a

id si

ted

with

or

inst

ead

of a

VO

R.

TA

CA

N

Prov

ides

pilo

ts w

ith in

dica

tions

of b

eari

ng to

gro

und

tran

smitt

ing

stat

ion.

Non

Dir

ectio

nal B

eaco

n

VH

F O

mni

dire

ctio

nal R

angi

ng p

rovi

des m

agne

tic b

eari

ng in

form

atio

n fo

r lo

ng

rang

e na

viga

tion

(up

to 1

75 N

M).

VO

R

Prov

ides

dis

tanc

e se

para

tion

mea

sure

men

t bet

wee

n an

air

craf

t and

the

grou

nd u

nit.

Dis

tanc

e M

easu

ring

Equ

ipm

ent

Mic

row

ave

Lan

ding

Sys

tem

ML

S

Inst

rum

ent L

andi

ng S

yste

m h

elps

air

craf

t lan

d sa

fely

on

a ru

nway

and

it co

nsis

ts o

f a

Loc

aliz

er, G

lide

Slop

e, a

nd M

arke

rs.

ILS

Air

field

Nav

igat

iona

l Aid

s (N

AV

AID

S) a

re sm

all s

enso

rs lo

cate

d ar

ound

the

airp

ort

that

giv

e ai

rcra

ft in

form

atio

n fo

r la

ndin

g an

d ta

keof

f.N

AV

AID

S

Thi

s inc

lude

s Air

port

Sur

veill

ance

Rad

ar (A

SR-9

), A

irpo

rt S

urfa

ce D

etec

tion

Equ

ipm

ent (

ASD

E-X

/ASD

E-3

), Su

rfac

e M

ovem

ent A

dvis

or, A

irpo

rt M

ovem

ent A

rea

Safe

ty S

yste

m (A

MA

SS) a

nd D

igita

l Bri

ght R

adar

Indi

cato

r T

ower

Equ

ipm

ent

(DB

RIT

E).

Surv

eilla

nce

20

Futu

re A

TM

App

licat

ions

The

se se

rvic

es in

clud

e A

utom

atic

Dep

ende

nt S

urve

illan

ce –

Bro

adca

st (A

DS-

B) a

nd T

raff

ic In

form

atio

n Se

rvic

e –

Bro

adca

st (T

IS-B

).T

raff

ic a

nd S

urve

illan

ce S

ervi

ces

Dat

a L

ink

Surf

ace

Info

rmat

ion

and

Gui

danc

e se

rvic

e de

liver

s cur

rent

, sta

tic g

raph

ical

air

port

map

to fl

ight

cr

ew.

D-S

IG

Dat

a L

ink

Log

on is

the

Dat

a In

itiat

ion

Cap

abili

ty se

rvic

e th

at a

llow

s aut

omat

ic lo

gon

and

cont

act w

ith th

e sy

stem

.D

LL

Dat

a L

ink

Flig

ht U

pdat

e Se

rvic

e D

-FL

UP

Dat

a L

ink

Aut

omat

ic T

erm

inal

Info

rmat

ion

Serv

ice

D-A

TIS

Dat

a L

ink

Sign

ifica

nt M

eteo

rolo

gica

l Inf

orm

atio

n D

-SIG

ME

T

Dat

a L

ink

Run

way

Visu

al R

ange

D

-RV

R

Dat

a L

ink

Ope

ratio

nal T

erm

inal

Info

rmat

ion

Serv

ice.

D

-OT

IS

Dat

a L

ink

Flig

ht In

form

atio

n Se

rvic

es, i

nclu

ding

D-O

TIS

, D-R

VR

, D-S

IGM

ET

, D-A

TIS

and

D-F

LU

P.

D-F

IS

AD

AP

serv

ices

incl

ude

Flig

ht P

lan

Con

siste

ncy

(FL

IPC

Y),

Flig

ht P

ath

Inte

nt (F

LIP

INT

), Pi

lot P

refe

renc

es

Dow

nlin

k (P

PD) a

nd S

yste

m A

cces

s Par

amet

ers (

SAP)

.A

utom

atic

Dow

nlin

k of

Air

born

e Pa

ram

eter

s (A

DA

P) S

ervi

ces

AM

C se

rvic

e pr

ovid

es a

one

-way

upl

ink

alte

rnat

ive

to v

oice

com

mun

icat

ions

for

cont

actin

g ai

rcra

ft v

ia d

ata

link,

in th

e ev

ent t

hat a

“st

uck

mic

roph

one”

bloc

ks th

e vo

ice

chan

nel.

AT

C M

icro

phon

e C

heck

(AM

C)

CO

TR

AC

serv

ice

prov

ides

a m

echa

nism

to e

stab

lish

and

agre

e tr

ajec

tory

con

trac

ts b

etw

een

pilo

ts a

nd

cont

rolle

rs in

rea

l-tim

e.C

omm

on T

raje

ctor

y C

oord

inat

ion

(CO

NT

AC

)

D-T

AX

I ser

vice

pro

vide

s aut

omat

ed a

ssis

tanc

e to

con

trol

lers

and

pilo

ts to

per

form

com

mun

icat

ion

exch

ange

s du

ring

gro

und

mov

emen

t ope

ratio

ns.

Dat

a L

ink

Tax

i Cle

aran

ce (D

-TA

XI)

AC

M se

rvic

e pr

ovid

es a

utom

ated

ass

ista

nce

to p

ilots

and

con

trol

lers

for

cond

uctin

g tr

ansf

er o

f all

AT

C

com

mun

icat

ions

(bot

h vo

ice

and

data

).A

TC

Com

mun

icat

ion

Man

agem

ent (

AC

M)

DC

L se

rvic

e pr

ovid

es a

utom

ated

ass

ista

nce

for

the

requ

est a

nd d

eliv

ery

of d

epar

ture

info

rmat

ion

& c

lear

ance

.D

epar

ture

Cle

aran

ce (D

CL

)

AC

L se

rvic

e pr

ovid

es th

e m

echa

nism

to r

eque

st a

nd r

ecei

ve c

lear

ance

s, in

stru

ctio

ns, a

nd n

otifi

catio

ns.

AT

C C

lear

ance

(AC

L)

Con

trol

ler-

Pilo

t Dat

a L

ink

Com

mun

icat

ions

(CPD

LC

) ser

vice

s rep

lace

voi

ce c

omm

unic

atio

ns fo

r cl

eara

nces

be

twee

n co

ntro

ller

and

airc

raft

with

dig

ital m

essa

ges.

CPD

LC

Ser

vice

s

Des

crip

tion

Futu

re A

TM

App

licat

ions

21

Cur

rent

AO

C A

pplic

atio

ns

Man

ual a

nd a

utom

atic

upl

ink

of c

onne

ctin

g fli

ghts

, ET

D, a

nd g

ate

befo

re la

ndin

g.G

ate

and

Con

nect

ing

Flig

ht S

tatu

s

Del

iver

ing

next

flig

ht a

ssig

nmen

t, es

timat

ed ti

me

of d

epar

ture

&ga

te in

form

atio

n.Fl

ight

Log

Tra

nsfe

r

Loa

d sh

eet a

nd c

argo

info

rmat

ion

uplin

ked

to c

ockp

it au

tom

atic

ally

or

upon

req

uest

.L

oads

heet

Req

uest

/Tra

nsfe

r

Prov

idin

g th

e op

erat

ors w

ith th

e ab

ility

to r

eque

st a

nd r

ecei

ve th

e A

OC

-dev

elop

ed fl

ight

pl

an fo

r co

mpa

riso

n to

that

ass

igne

d by

AT

C a

nd fo

r lo

adin

g in

toav

ioni

cs.

Flig

ht P

lan

Tra

nsfe

r

Rep

ortin

g A

ircr

aft C

ondi

tion

Mon

itori

ng S

yste

m (e

ngin

e an

d sy

stem

s) v

ia a

utom

atic

do

wnl

ink

and

on r

eque

st.

Eng

ine

Perf

orm

ance

Rep

orts

Rep

ortin

g fli

ght s

tatu

s (su

ch a

s mal

func

tion

repo

rts t

o m

aint

enan

ce).

Flig

ht S

tatu

s

Aut

omat

ic d

ownl

ink

of p

ositi

on d

urin

g cl

imb,

cru

ise

and

desc

ent p

ositi

ons o

f flig

ht.

Posi

tion

Rep

ort

Wea

ther

Req

uest

incl

udes

flig

ht c

rew

req

uest

for

airp

ort w

eath

er.

Wea

ther

rep

orts

in

clud

e M

ET

AR

s and

TA

Fs.

Wea

ther

Req

uest

/Wea

ther

Not

ice

to A

irm

en R

eque

st/N

otic

e to

Air

men

serv

ice

deliv

ers A

TIS

dat

a th

at in

clud

es a

ny

imm

edia

te N

OT

AM

s ava

ilabl

e.

NO

TA

M

Mov

emen

t ser

vice

mes

sage

s, in

clud

ing

Out

, Off

, On,

In r

epor

t dat

a th

at is

aut

omat

ical

ly

rout

ed to

the

AO

C M

ovem

ent C

ontr

ol S

yste

m.

Out

Off

On

In (O

OO

I)

Supp

ort s

ervi

ces t

hat i

nter

act w

ith p

ilot,

cabi

net c

rew

and

air

craf

t in

orde

r to

turn

the

airc

raft

aro

und

at th

e ga

te.

Air

port

/Ram

p A

rea

Ope

ratio

ns

Flig

ht c

rew

-to-

com

pany

voi

ce se

rvic

es a

nd fl

ight

cre

w-t

o-fli

ght c

rew

voi

ce

com

mun

icat

ions

.C

ockp

it V

oice

Ope

ratio

n

Des

crip

tion

Cur

rent

AO

C A

pplic

atio

ns

22

Futu

re A

OC

App

licat

ions

Allo

win

g ne

w v

ersi

ons o

f sof

twar

e to

be

uplo

aded

the

airc

raft

syst

ems.

Soft

war

e L

oadi

ng

Rep

laci

ng m

any

of th

e pa

per

docu

men

ts c

urre

ntly

bei

ng r

equi

red

to b

e ca

rrie

d in

the

cock

pit (

e.g.

, Air

craf

t Man

ual a

nd A

ICs)

.O

nlin

e D

ocum

enta

tion

Tra

nsfe

r

Allo

win

g th

e ca

bin

crew

to c

ompl

ete

the

airc

raft

’s c

abin

equ

ipm

ent l

og

elec

tron

ical

ly a

nd se

nd th

is lo

g to

the

AO

C.

Cab

in L

og B

ook

Tra

nsfe

r

Allo

win

g th

e fli

ght c

rew

to c

ompl

ete

the

airc

raft

’s te

chni

cal l

og

elec

tron

ical

ly a

nd se

nd th

is lo

g to

mai

nten

ance

bas

e.T

echn

ical

Log

Boo

k U

pdat

e

Aut

omat

ic w

eath

er r

epor

ting

in r

eal-t

ime.

Rea

l Tim

e W

eath

er R

epor

t

Allo

win

g ai

rlin

e gr

ound

mai

nten

ance

staf

f to

requ

est i

nfor

mat

ion

from

on

-boa

rd sy

stem

s so

that

a d

iagn

osis

of p

robl

ems c

an b

e pe

rfor

med

aw

ay

from

the

airc

raft

’s b

ase.

Onl

ine

Tec

hnic

al T

roub

le

Shoo

ting

Wea

ther

info

rmat

ion

sent

to th

e ai

rcra

ft in

the

form

that

is su

itabl

e fo

r gr

aphi

cal d

ispl

ays i

n th

e co

ckpi

t (e.

g., v

ecto

r gr

aphi

cs).

Gra

phic

al W

eath

er

Info

rmat

ion

Des

crip

tion

Futu

re A

OC

App

licat

ions

23

Exa

mpl

e 1:

PD

C C

omm

unic

atio

n C

hara

cter

istic

s (C

urre

nt A

TM

)

Coc

kpit/

AT

CSo

urce

/Des

tinat

ion

VH

F vo

ice

/ AC

AR

SC

omm

unic

atio

n lin

ks u

sed

No

Aut

hent

icat

ion

No

Enc

rypt

ion

95 -

98%

Ava

ilabi

lity

< 10

-6In

tegr

ity R

equi

red

(Und

etec

ted

Err

or R

ate)

Non

ePr

eced

ence

1,20

0 bp

sE

stim

ated

ban

dwid

th r

equi

red

5 m

inR

equi

red

Res

pons

e or

Del

ay T

ime

(1.2

5 / 2

.25)

msg

/flt

Occ

urre

nce

(upl

ink/

dow

nlin

k)

( 180

0 / 3

04 )

bits

Info

rmat

ion

Uni

t Siz

e (u

plin

k/do

wnl

ink)

Val

uePa

ram

eter

24

Exa

mpl

e 2:

DC

L C

omm

unic

atio

n C

hara

cter

istic

s (Fu

ture

AT

M ~

203

0)

Sour

ce/D

estin

atio

n

FCS

Com

mun

icat

ion

links

use

d

Yes

Aut

hent

icat

ion

No

Encr

yptio

n

Ava

ilabi

lity

Inte

grity

Req

uire

d (U

ndet

ecte

d Er

ror R

ate)

Hig

hPr

eced

ence

320

bps

Estim

ated

ban

dwid

th re

quire

d

7 se

c ET

E, 9

5%

Req

uire

d R

espo

nse

or D

elay

Tim

e

1 pe

r flig

ht a

irpor

tO

ccur

renc

e

278

byte

s upl

ink

/ 24

9 by

tes d

ownl

ink

Info

rmat

ion

Uni

t Siz

e

Val

uePa

ram

eter

25

Air

line

Adm

inis

trat

ive

Com

mun

icat

ion

(AA

C)

●A

AC

is p

erta

inin

g to

airl

ine

to a

ircra

ft m

essa

ging

app

licat

ions

,in

clud

ing:

–A

irlin

es G

ate

Con

nect

ion

Info

rmat

ion

–M

edic

al A

ssis

tanc

e R

eque

sts

–C

rew

Sch

edul

e an

d Lo

dgin

g In

form

atio

n–

Mis

cella

neou

s Fre

e Te

xt C

rew

Info

rmat

ion

–Pa

ssen

ger l

ists

–A

ircra

ft C

ater

ing

–B

agga

ge h

andl

ing

–A

ircra

ft fu

elin

g –

Lost

and

foun

d–

In-f

light

Ass

ista

nce

–D

uty

Free

Sal

es, i

.e. p

urch

ases

in th

e ai

r

26

AA

C C

omm

unic

atio

n C

hara

cter

istic

s

Sour

ce/D

estin

atio

n

Com

mun

icat

ion

links

use

d

No

Aut

hent

icat

ion

No

Encr

yptio

n

95 –

98%

Ava

ilabi

lity

10-6

to 1

0-7In

tegr

ity R

equi

red

(Und

etec

ted

Erro

r R

ate)

Non

ePr

eced

ence

VH

F sy

stem

-1,

200

bps

Sate

llite

syst

em -

appr

ox. 1

0,00

0 bp

sEs

timat

ed b

andw

idth

requ

ired

< 1

min

del

iver

y

Rej

ect m

essa

ges >

5 m

in o

ldR

equi

red

Res

pons

e or

Del

ay T

ime

20 -

30 m

essa

ges p

er fl

ight

segm

ent

Occ

urre

nce

Mes

sage

s < 2

56 b

ytes

Mul

ti-bl

ock

mes

sage

s < 3

,000

byt

esIn

form

atio

n U

nit S

ize

Val

uePa

ram

eter

27

Surf

ace

Arc

hite

ctur

e Fu

nctio

ns

●D

efin

ing

netw

ork

func

tions

as b

uild

ing

bloc

ks o

f su

rfac

e ar

chite

ctur

e in

stea

d of

phy

sica

l ent

ities

(e

.g.,

rout

ers,

switc

hes,

or w

irel

ess a

cces

s poi

nts)

●Fu

nctio

ns o

r co

mpo

nent

arc

hite

ctur

es m

ay

incl

ude:

–A

ddre

ssin

g/R

outin

g–

Net

wor

k M

anag

emen

t–

Perf

orm

ance

–Se

curi

ty–

Oth

er (s

uch

as su

rfac

e w

irel

ess i

nfra

stru

ctur

e,

appl

icat

ions

serv

ices

and

stor

age)

28

Cap

abili

ty &

Mec

hani

sms o

f Com

pone

nt A

rchi

tect

ures

Secu

rity

mec

hani

sms i

nclu

de fi

rew

alls

, sec

urity

pol

icie

s and

pr

oced

ures

, filt

ers a

nd a

cces

s con

trol

list

s. T

hese

co

ver,

for

inst

ance

, phy

sica

l sec

urity

and

aw

aren

ess,

prot

ocol

and

app

licat

ion

secu

rity

, aut

hent

icat

ion,

en

cryp

tion

and

decr

yptio

n, n

etw

ork

peri

met

er a

nd

rem

ote

secu

rity

.

Prot

ectin

g su

rfac

e ne

twor

ks

and

serv

ices

fr

om u

naut

hori

zed

acce

ss, m

odifi

catio

n,

dest

ruct

ion,

or

disc

losu

re t

o en

sure

the

in

tegr

ity,

conf

iden

tialit

y,

and

avai

labi

lity

of

thes

e ne

twor

ks

and

syst

em r

esou

rces

and

dat

a.

Secu

rity

QoS

, SL

As,

and

polic

ies.

QoS

mec

hani

sms i

nclu

de, f

or

exam

ple,

Err

or D

etec

tion/

Cor

rect

ion,

Ada

ptiv

e M

odul

atio

ns, A

utom

atic

Rep

eat R

eque

st,

Prio

ritiz

atio

n, S

ched

ulin

g, T

raff

ic S

hapi

ng/P

olic

ing,

In

tSer

v an

d D

iffSe

rv.

Prov

idin

g ne

twor

k re

sour

ces

to

supp

ort

netw

ork

perf

orm

ance

re

quir

emen

ts

(cap

acity

, del

ay, a

nd R

MA

).

Perf

orm

ance

Net

wor

k m

anag

emen

t mec

hani

sms i

nclu

de n

etw

ork

man

agem

ent p

roto

cols

(suc

h as

SN

MPv

3, C

MIP

, or

CM

OT

), de

vice

s man

agem

ent a

nd n

etw

ork

conf

igur

atio

n.

Prov

idin

g ne

twor

k m

onito

ring

, con

figur

atio

n an

d tr

oubl

esho

otin

g fo

r th

e su

rfac

e ne

twor

k.

A s

urve

y of

CO

TS

netw

ork

mon

itori

ng a

nd c

onfig

urat

ion

soft

war

e pr

oduc

ts

wer

e co

nduc

ted.

The

se

soft

war

e to

ols

can

pote

ntia

lly

be

inte

grat

ed in

to th

e su

rfac

e ne

twor

ks fo

r m

onito

ring

and

con

figur

ing.

Net

wor

k M

anag

emen

t

1)A

ddre

ssin

g m

echa

nism

s for

bot

h IP

v4 a

nd IP

6 w

ere

eval

uate

d fo

r su

rfac

e ne

twor

ks.

Agg

rega

tion

vers

us

Cla

ssle

ss In

ter-

Dom

ain

Rou

ting

(CID

R) a

nd o

ther

co

nsid

erat

ions

, inc

ludi

ng D

ual S

tack

, 6t

o4 g

atew

ay,

Priv

ate

Add

ress

ing,

Net

wor

k A

ddre

ss T

rans

latio

n (N

AT

), M

ultic

ast,

and

Mob

ility

.2)

Rou

ting

mec

hani

sms i

nclu

de R

outin

g Fl

ows

Est

ablis

hmen

t, R

outin

g B

ound

arie

s and

Rou

ting

Flow

s M

anip

ulat

ion.

Prov

idin

g ro

bust

an

d fle

xibl

e co

nnec

tivity

be

twee

n de

vice

s. N

etw

ork

devi

ces

such

as

IP

rout

ers,

switc

hes,

SON

ET

hub

s, m

odem

s, w

irel

ess

acce

ss

poin

ts,

firew

alls

, ser

vers

and

end

-use

r st

atio

ns.

And

, c

onne

cted

to

the

core

sur

face

ne

twor

k, t

here

are

man

y di

vers

e pi

eces

of

har

dwar

e, s

uch

as A

SR-9

rad

ar u

nits

, R

TR

rad

ios,

Loc

aliz

ers,

Glid

e Sl

opes

, M

arke

rs, A

SDE

-X, a

nd o

ther

s.

Add

ress

ing/

Rou

ting

Mec

hani

sms

Cap

abili

tyFu

nctio

n

29

Sum

mar

yN

etw

ork

Arc

hite

ctur

e Pr

oces

s

30

Con

clus

ions

●B

ased

on

resu

lts o

f rec

ent N

ASA

stud

ies:

–A

bet

ter

unde

rsta

ndin

g of

cur

rent

stat

e of

surf

ace

com

mun

icat

ions

has

be

en g

aine

d.–

Still

insu

ffic

ient

info

rmat

ion

abou

t sta

keho

lder

’s e

xpec

tatio

ns &

nee

ds,

appl

icat

ions

, dev

ices

and

dat

a tr

affic

flow

s to

form

the

foun

datio

n up

on

whi

ch a

rob

ust a

nd fl

exib

le su

rfac

e ar

chite

ctur

e ca

n be

dev

elop

ed.

–H

owev

er, a

goo

d st

artin

g po

int f

or fu

rthe

r re

sear

ch e

ffor

ts.

●In

tero

pera

bilit

y am

ong

appl

icat

ions

can

not b

e di

scer

ned

in

cont

ext o

f tod

ay’s

air

port

com

mun

icat

ions

or

any

futu

re tr

ends

be

ing

set b

y av

iatio

ns &

pol

icy-

mak

ing

auth

oriti

es.

●In

tern

etw

orki

ng u

sing

IPv6

hel

p ac

hiev

e in

tero

pera

bilit

y.●

Oth

er e

ffor

ts su

ch a

s pac

ket-

base

d FT

I net

wor

k, S

WIM

, etc

.

31

TH

E E

ND