This document provides an overview of using UHF satellite communications with DAMA protocol for aeromedical applications. It discusses: 1) The introduction and objectives of applying this technology for aeromedical crews. 2) A systems engineering approach was used including analyzing user requirements, alternatives like UHF SATCOM, IMMARSAT, HF radio and commercial systems, and selecting UHF SATCOM with existing PSC-5 radios. 3) Details are given on the space segment, earth terminals, network control, TDMA and DAMA protocols to optimize use of limited satellite resources among multiple users.

1. 1
Aeromedical Application of UHF
SATCOM Using DAMA Protocol
Frank W Meissner, Col, USAF, MC, FS
Eric Dube, Capt, USAF
Bridget Moorman, Maj, USAFR
Jeffery Carbonetti, 1Lt, USAF

2. 2
Overview
• Introduction
• Systems Engineering
• DAMA Technical Tutorial
• Program Management
• Data Results
• Conclusions

3. 3
Introduction
• What Is Useful?
– Satellite Communication Principles
• What Is New?
– Satellite Communication Future Broadband Solution
• What Is Unique?
– New Communication capabilities for Medics
• What Was Learned?
– Evolutionary Prototype(s) For Requirements Capture
– Workflow Integration

4. 4
Systems Engineering
• User Need Drives Process
• Systems Requirements Analysis
• Trade-study Of Existing COTS/NDI Solutions
• Selection Of Design Solution
• Integration Of COTS/GOTS/NDI
• Prototype Deployment And Operational Testing
• “Off-the-shelf” System Available For End-user

5. 5
User Requirements
•Technical Capabilities
•E-mail & Voice Communications Capability In Cargo Hold
•Communication Channel Dedicated To Aeromedical Crew
•Low Cost
•Total Budget < $600K
•Rapid Time Line For Development
• < 7 mo’s
•Focused Airframe
•Initial Capability Only In C-141
•No Additional Crew-members
•Minimal Training Required For Systems Operation

6. 6
Key Performance Parameters
Key Performance Parameter Threshold Objective
Allow Standard e-mail X X
Allow e-mail attch, Voice, Chat Sessions X X
No A/C Modification - C-130 X
No A/C Modification - C-141 X
Routine Ops Without Commo Specialist X X
Portability Litter 1 person Suitcase
Build With AE Certified COTS/GOTS/NDI X
Range & Availability Of Communications 95% 100%
Consistent With Methodology Selected
System Capacity 4 1Kbyte messages/hr 4 17Kbyte messages/hr
Delivery To Customer < 7 mo’s < 6 mo’s

7. 7
Analysis of Alternatives -
UHF SATCOM
• PRO
– UHF SATCOM Drops In Most AMC Aircraft
– Hatch Mounts For Those Without Drops
– PSC-5 & Other Radios Common In DOD
– Existing DoD Infrastructure - (Gateways)

8. 8
Analysis of Alternatives -
UHF SATCOM
• CON
– No Coverage @ >70 Degree Latitude
– Saturation/Access Time Might Be Problem
•Medics May Have Relatively Low Priority

9. 9
Analysis of Alternatives -
IMMARSAT “Aero C”
• PRO
– System And Infrastructure Already @ AMC
(TACC)
• CON
– Expensive For AMC As Currently Used
– Low Data Rate (600 bps)
– Data Only (No Voice)
– Technical Unknowns Of Routing System To A/C

10. 10
Analysis of Alternatives -
HF Radio
• PRO
– Low Op Costs - No Usage Fees
– ALE Allows Medics To Use Without Commo Spec
– Global HF Network Already Exists (Voice Only)
• CON
– Ground Coverage Limited
– Expensive Upgrade HF Voice To HF Data Networks
– Strategic Use Of HF Base Stations => DoD Approval

11. 11
Analysis of Alternatives -
Commercial Airborne Systems
• PRO
– Private Sector Maintains Infrastructure
– Solution Across All Airframes
• CON
– Airborne Systems All Require Aircraft Mod
– VENDOR-SPECIFIC ANTENNA MOUNT
– DoD Does Not Control Infrastructure
– High Usage Costs
– Private Users Compete for Channel Capacity
– Primarily Voice Network - Security Concerns

12. 12
Final Design Solution
• Based on Project Requirements and Analysis of Alternatives
• Pursued UHF SATCOM Solution
– Minimum Cost
• Low Initial Cost
– Used Existing PSC-5 SATCOM RADIOS (Many Already In
SG Inventory)
– Used Existing ESC Base Stations (NIPRNET Gateways)
• Low Support Cost
– Airtime Free To Users
– Minimum Schedule Risk
• Mature Technology
• Previously Demo’ed Or Certified For Operational Use
– Expected System Performance
• Meets All Performance Thresholds and Objectives

13. 13
Space Communications
Architecture
Satellite-satellit
e
Laser Relay
Satellite-satellite
RF Relay
Satellite
Link
Satellite
Ground
Station
Satellite
Ground
Station
Satellite
Link
Radio
Frequency
Link
Ionospher
e
Laser
Rela
y
Microwave
Link
Maritim
e
Link
Microwave
Link
POT
S
SECURE
Cable
Link
Under
Sea
Cable
Link
POT
S
Coax
Cabl
e
POT
S
LAN

14. 14
SATCOM & DAMA Overview
• Space Segment
• Ground Segment
• Control Segment
• TDMA
• DAMA
• DAMA Network control

15. 15
Communications Satellite System
Network Components
•Space Segment
•Earth Terminal Segment
•Control Segment

16. 16
Air Force SatCom Space Segment
Host Satellites
Fltsatcom
1 500-Khz (Relay Type)(UHF)
12 5-Khz (Processed, Non-processed) (UHF)
Geosynchronous orbit
SDS
12 5-Khz (Processed) (UHF)
1 Single-channel Transponder (Processed) (UHF)
Elliptical orbit
DSCS IIIB
1 Single-channel Transponder (Processed) (UHF)
Geosynchronous orbit
AFsatcom

17. 17
Earth Terminal Segment
• Provides Signal And Data Processing
Necessary To Receive And Transmit Signals
From And To The Satellite And User
• In Simplest Form Consists Of
– Antenna With Transmit And Receive Capabilities
– Modulator, Up-converter And Power Amplifier
(PA) For Transmitting
– Low Noise Amplifier (LNA), Down-converter
And Demodulator For Receiving

18. 18
MODULATOR
UP -
CONVERTER
HIGH POWER
AMPLIFIER
Basic Earth
Terminal Configuration
Digital
Data
DEMODULATOR
DOWN -
CONVERTER
LOW NOISE
AMPLIFIER
Digital
Data

19. 19
I/O DEVICE
A/D & D/A
CONVERTOR
CRYPTO
Digital Processing
Earth Terminal Elements
CODER
TRANSEC
Modulator
Demodulat
or

20. 20
Control Segment
•Spacecraft Control
•Communications Payload Control
•Access Control

21. 21
Earth
Termin
al
User
Earth
Termin
al
User
Control
Facility
Control
Facility
¥Spacecraft
Control
¥Communications
Payload Control
Acces
s
Contro
l
TT&C
Control Segment Requirements

22. 22
Spacecraft Control
• Concerned With Operation Of Spacecraft
Subsystems Except For Communications
Subsystem

23. 23
Communication Payload Control
• Concerned With Configuration & Operating Levels
Of The Communications Subsystem (Payload)
• Encompasses
– Antenna Connectivity, Antenna Pointing, Power Output
Of Transponder, Shutdown/power Up Of Transponders,
Gain Of Transponder, Switch To Redundant Equipment

24. 24
Access Control
• Day-to-day Operation Of Networks Using The
Satellite Communications Payload
– Objective Optimize Availability Limited Satellite
Transponder Resources To Multiple Users
• Types of Access
– Transponder
• Example: Time Division Multiple Access (TDMA)
– User
• Example: Demand Assignment Multiple Access (DAMA)

25. 25
Generic Network Control System
TT&C
Earth
Termin
al
TT&C
Earth
Termin
al
Networ
k
Control
Center
Earth
Termin
al
User
Earth
Termin
al
User
Service
Requests
Service
Requests
Access
Authorizations
Access
Authorizations
Manag
e
Control
Satellite
Relocation
Comm Payload
Reconfiguration
Traffic

26. 26
Time Division Multiple Access
(TDMA)
• Multiple User Transponder Access Technique
Makes Available Stream Of Time Slots Allocated
To Users
• Each Earth Terminal Take Turns Transmitting
Bursts Of Data Through Common Transponder
• Time Resources Divided Into Small Segments
With Brief Gaps (Guard Time) Between
Segments

27. 27
User 1 User 2 User 3 User 4
Guard
Bands
TDMA Satellite
Transponder Access
Transpond
er
Bandwidth
Tim
e
f

28. 28
TDMA Frames
• All Earth Terminals In TDMA Network Must
Know When To Transmit/Where To Place
Information Burst
• Accomplished By Organizing TDMA Transmissions
Into Frames
• Each Frame Contains Reference Burst That
Establishes Timing To Synchronize Transmissions

29. 29
TDMA Frame Structure
Burst
From
ET-1
Burst
From
ET-2
Burst
From
ET-3
Burst
From
ET-n
OW
Ranging
Link
Test
Guar
d
Band

30. 30
Demand Assigned
Multiple Access (DAMA)
• Maximizes Transponder Access
– Reduces System Idle Time
• TDMA Transponder Access Techniques
• DAMA
– Assigns Time Slot To Idle Transponder
– Based On User Requests
• DAMA Overlays Prioritization “Rules” Onto
Transponder Access (TDMA) Protocol

31. 31
DAMA Network Control
• US Navy Provides UHF Transponder Access
• Uses Centralized Network Control
• Network Control Station (NCS)
– Receives
– Processes
• Requests For DAMA Services

32. 32
Centralized Control -
DAMA System
Calling
ET
Control
Station
Called
ET
Call
Set
Up

33. 33
Satellite Coverage is to 75 degrees latitude North &
South
SATELLITE FOOTPRINTS ARE ELLIPTICAL AND OVERALAP EACH OTHER AT DOTTED LINES
DAMA Network
Control System

34. 34
DAMA Network Control
• Service Requests Are Generated
– By Earth Terminals In DAMA Network
– Sent To NCS Over Satellite
– Uses Return Order-wire (ROW) Block In Frame
• The NCS Responds With Channel Allocation
– Uses Forward Order-wire (FOW) Block In Frame

35. 35
Frame N-1 Frame N Frame N+1
Forward
Order wire
Return
Order wire
Communications
Slot Slots Slots
Time
Network Time
Structure/Frames

36. 36
A/D Analog
Converter
Data
Port
Crypto
KY-57/58
KYV-5
KG-84
DAMA
Controll
er Mode
m
Frequency
Synthesizer
225-400
MHz
UHF
P.A.
O-W
Encryptio
n
O-W
Processo
r
TDMA/DAMA
Earth Terminal Configuration

37. 37
Frame
FOW ROW COM
Circuit
Service
Slot
Message
Service
Slot
Circuit
Service
Slot
Message
Service
Slot
..
.
Preambl
e
SOM
Burst
Type
Data
Field
Circuit
Burst
Kind
Flush
Guar
d
Time
600, 1200, 2400
or 3000 sps
Variable # of building
Blocks
25.208
ms
Interleave
d
Conv.
8.96
secon
ds
Circuit Communications - 5 KHz
Protocol Messaging Standard

38. 38
DAMA Network Control
• Frame Contains Communication Segment
– Where Users Data/information Resides
• Dependent On Satellite Coverage, User Requests
– Local (Within Single Satellite “Footprint”)
– Global (Using Multiple Hop (MHOP) Routings)
• MHOP By Relay Capability Within NCS

39. 39
Basic System Architecture
Space Segment
• Four Geo-sync Orbit Satellite Footprints
– Global Coverage At < 70 Deg N/S LAT (Appx)
• Four Network Control Stations
– Located Guam, Hawaii, Norfolk, Naples
– Control Transmission Traffic
– Act As Relay Stations For Inter-footprint
Transmissions
• E.G., Hickam AFB to Scott AFB

40. 40
Basic System Architecture
Airborne Segment
• A/E Aircraft With USTS Provisions
– System Installed For Back-end Commo
• UHF SATCOM DAMA Suitcase Terminal
• Interfaces With Aircraft Provide
– 28 Volt DC Power
– UHF SATCOM Antenna
• Portable System (Carry On Pre-flight)
– Two Suitcase Configuration (60 lbs , 100 lbs)
– Operated In Cargo Bay

41. 41
Basic System Architecture
Airborne Terminal
OPERATOR
SUITCASE
SUPPORT
SUITCASE
Bubble-Jet Printer
(Behind Laptop) PSC-5 Radio
Panasonic
“Toughbook”
Laptop
High-powered
Amplifier
Power Distribution
& EMI Filtering
Storage Drawer

42. 42
Basic System Architecture
Ground Segment - March ARB
• Phase I: Ground-based UHF SATCOM
Terminal
– Very Similar To Airborne Terminal
– System Will Also Require Its Own Antenna
– Allows For Terminal-to-terminal Voice & Data
• Phase II: NIPRNET Routing
– System Connects To Router & SMTP Server
– Greatly Increase Span Airborne Messaging
Including Non-terminal Based Participants

43. 43
Ground-Based Terminal
Configuration (Phase I)

44. 44
Phase II - System in NIPRNET
Gateway Configuration
Antenna cable run through window and down to ground.
ViaSat VDC-500IP UHF
SATCOM/IP Router
ViaSat VDC-400 DAMA
Data Controller

45. 45
System in C-141
Jump-seat Configuration
Interface cables routed
behind jumpseats and
taped to floor
USTS Interface
Panel (FS 490)
Cargo Strap securing
System to floor

46. 46
Terminal Equipment
• Panasonic Toughbook 27
• 266 MHz
• 4 GB HDD
• 10x CD-ROM
• 32 MB RAM
• PSC-5 “Spitfire” Radio
• COMSEC Keyfill Device
• WKW-7/MRC-50 Battery
• Bubble-jet Printer
•100W Power Amplifier
• Interface Cabling
• Manpack UHF SATCOM Antenna (Ground Use)

47. 47
2nd Generation Suit-Case

48. 48
Project Milestones/Timeline
• 31 Aug 98: Official Tasking From USAF/SGX
• 9 Nov 98: Funds Arrive At 311 HSW
• 12 Nov 98: SOO Sent To Industry
• 4 Dec 98: Industry Proposals Received
• 7-10 Dec 98: Proposals Evaluated
• 22 Jan 99: Contract Award
• ViaSat, Inc/ACS Technologies

49. 49
• Flight Certification Process (Mar - May 99)
– 30-31 Mar Ground Testing March ARB
– 12-15 Apr EMI/Power Profile WPAFB
– 1-2 May Flight Tests From March ARB
• Training - May 99
– 452 AE Crew And Ground Comm Personnel
• Operational Test Flights - Jul 99
Project Milestones/Timeline

50. 50
Project Results
• Results of fast-paced COTS/GOTS/NDI Effort
– COST
• Completed With < 75% Of Allotted Funds
– SCHEDULE
• Met 6 month “A to Z” Objective (8 Month Threshold)
• Funds Arrived 9 Nov 98, Demonstration Complete 2 May 99
– PERFORMANCE
• Met All Threshold Performance Requirements
• Met Or Exceeded 75% Of Objective Requirements
– Not Operable On AE CRAF Or C-9A Without Modification
» C-9A Modification Planned For Ramstein AB
– System Requires More Than 1 Man-portable Suitcase

51. 51
Project Data Results
User Survey Methodology
5 4 3 2 1
Strongly Somewhat Somewhat Strongly N/A
Agree Agree Disagree Disagree

52. 52
Project Data Results
User Survey, N=20
• Easy System Setup = 2.86
• Overall Voice Performance Is Good = 1.83
• Overall Data Performance Is Good = 1.71
• Terminal Will Provide Better Patient Care = 1.60
• Especially Suited For Emergencies = 2.31
• Especially Suited For Routine Use = 1.67
• System Was Too Labor Intensive = 3.0
• Recommend Operational Adoption = 1.75

53. 53
Initial Test Data
• Total Messages Attempted - 123
• Total Messages Sent at 1st Attempt - 117 (95%)
• 100% Messages Sent Using 2nd Attempt
• Point Estimate Band Width Estimates
∙ 54 Kb “Form-Flow” packaged file 207 bits per
second
∙ 175 Kb Video clip file 14 bits per second
∙ 99 Kb digital image 96 bits per second
• 14 Kb Adobe Acrobat patient record 156 bits per
second

54. 54
Sample JPEG Image File

55. 55
Network Throughput Testing
• Test File Sizes
• 2.95 Kbytes
• 27 Kbytes
• 69 Kbytes
• 147 Kbytes
• 30 Attempts @ Each File Size - Single Session
• Transmission Success Rate
– 120/130 (92%) On 1st Attempt
– 7/10 (85%) On 2nd Attempt
– Overall Success 127/130 (98%)

56. 56
Network Throughput
Test Data
50
100
150
200
2950 27000 69000 147000
BYTE
B
P
S
Average Effective Network
Throughput
= 104 ± 3.5 baud per second; n=120

57. 57
Conclusions
• COTS/GOTS/NDI Integration Demands
Expert Level Knowledge Of System
Components
• Rapid Development And Limited
Deployment Of Evolutionary Prototype(s)
Allows Low Risk Capture Of End-user
Operational Requirements And Workflow