Project Review presenters name review date

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UNITED STATES ANTARCTIC PROGRAM
Supervisory Control of Iridium LBTsfor
Continuous Multi-Channel ML-PPP
ApplicationsPresentation byGary Ferentchak
PE, PMPMay 19, 2004
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• NSF Tasking
• Multiple Channel Iridium (ISU to ISU) - Aggregate
  into Single Wider Stream
• Provide Continuous Network to Network Link
  Between the South Pole and Denver
• Servicing Critical and Emergency Traffic between
  South Pole ltgt Denver.
• O/S Cisco
• Single Iridium Channel (ISU to ISU)
• Time Sensitive Weather and Flight Operations Data
• E-mail (text based) South Poleltgt
  McMurdo
• O/S - Microsoft
• Short Burst Data (SBD) Supernova Alert

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• Iridium Multi-Channel Testing
• Cisco 2651 w/ASYNC Card
• 4x4 Channel, ML-PPP
• Primarily DAV, Limited Non-DAV
• Denver to Denver Denver to South Pole
• ISU to ISU (Motorola 9522 NAL AL3A-IG/S)
• DoD SIMS, Limited Testing with Commercial SIMs
• Early Testing Problem/Issue Identification
• Later Testing Microprocessor Designs

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Iridium Multi-Channel Testing Typical Line Drops
for 24 Hour Denver to South Pole Session
SouthPoleIridiumsh li   Tty Typ     Tx/Rx   
    Uses   Noise 
Overruns  (Cisco Dump)      33 TTY 
19200/19200      -    -    -    10       0    
0/0     34 TTY  19200/19200      -    -   
-     13       0     0/0      35 TTY 
19200/19200      -    -    -     18       0    
0/0      36 TTY  19200/19200      -    -   
-     14       0     0/0   (Sum55) DenverIridi
umsh li    Tty Typ     Tx/Rx   
    Uses   Noise  Overruns   (Cisco
Dump)    33 TTY  19200/19200 -    
-    -    -     14       0     0/0  
    34 TTY 
19200/19200 -      -    -    -    24       0    
0/0       
35 TTY  19200/19200 -     -    -    -     
4       0     0/0      
    36 TTY  19200/19200 -   -   
-    -     13       0     0/0 
(Sum55) Average Line Drops per Channel per 24
Hour Run 13.8 (Lock-ups not recorded)
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• Issue/Problem Details
• Call Drop Frequency (Presented as Average Up
  Timer per Channel)
• Denver to Denver Nights Weekends, 2 Hrs
  02 Min
• Denver to Denver Prime Business Hours, 30-40
  Min (Variable)
• Denver to South Pole Good days,
  20-45 Min (Variable)
• Denver to South Pole Bad days,
  10-20 Min (Variable)
• Seems to have cleared up some, (at Palmer
  Station as Well)
• Help from Boeing and Iridium
• Moved RTAD from McMurdo Station to South Pole
• Coordinated Testing, Including Multi-Channel -
  (No Data Analysis or Resolution to Date)

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Iridium Test Utility

• Engineering Use Only Software
• Common LBT Pre-Deployment Checkout Tasks
• Signal Strength Characterization
• Unattended start / stop
• Record to File
• Manual LBT Testing

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Iridium Multi-Channel Testing
Run Time to Session Failure Test Hours
Status 11 8 All LBTs non-responsive
12 27 All LBTs non-responsive 13
16 All LBTs non-responsive 14 44
All LBTs non-responsive 15 12 All LBTs
non-responsive 16 33 All LBTs
non-responsive 17 49 All LBTs
non-responsive 18 13 All LBTs
non-responsive 19 37 All LBTs
non-responsive 20 51 All LBTs
non-responsive Average Time Until All LBTs are
Non-Responsive and Session is Dead 29 Hours
Baseline Test Config 4x4 Channels DAV
Non-DAV Denver to Denver Denver to South Pole ISU
to ISU DoD SIMS ML-PPP
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• Iridium Multi-Channel Testing - Issues/Problems
• High Call Termination Rate
• Call drops
• Hung UART
• LBT Self-Initiated Power Down
• Occasional Failure to present DSR
• Occasional Unpredictable Changes in RF Signal
  Strength
• Multi-Drop, 2 to 4 LBTs Drop Simultaneously -
  Including Non-related Iridium Data Systems, but
  does not affect voice phone connection
• (Note Cisco IOS not Affected by Firmware
  Connect Response Error)

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• Issue/Problem Details Cont.
• Non-Responsive LBTs Breakout by Cause
• Self-Initiated Internal Power Down (DAV) (95
  approx)
• UART Lock-UP (4 approx)
• Occasional Failure to Present DSR (lt1) (Our
  Problem)
• Continuously Working with Boeing and NAL, (and
  Iridium via Boeing)
• Ratio Call Initiating 85, Receiving 15
• This is a Big Problem !!!
• The Cisco Router Successfully Recovers Responsive
  LBTs and Re-establishes the Recovered Channel
  Into the ML-PPP Session All the While Managing
  Data Flow Through Remaining Channels
• If LBTs are Responsive!

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Call Drops Who Drops First?
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Finally Yes - It Is a Known Problem
Yes - Iridium Is Aware of the
Problem No - Resolution Time Frame
Conclusion Things are Going Nowhere - Fast!
Time for Plan B
Graphics by Iridium
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• Supervisory Microprocessor
• Monitors LBT and RS232 Interface
• Monitors LBT Power State - Availability
• Monitors Cisco Call Attempts
• Monitors Call Status
• Detects Error States
• Resets Non-Responsive LBTs
• Different Algorithm for
• Call Initiating
• Call Receiving

Dual Microprocessor Unit Send Receive
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Supervisory Microprocessor Test

• Configuration
• 8 ea - Motorola 9522s
• Mode Data-After-Voice
• Type ISU to ISU
• SIMS DoD
• Traffic TCP/IP based ICMP
• Duration 21 Days
• Call from Denver
• Receive South Pole
• Manual Recovery for Non-Supervised LBTs

Call Recoveries LBT Denver South
Pole ASYNC-33 344
282 ASYNC-34 304 293 ASYNC-35
286 174 ASYNC-36 728
913 Total 1662 1662 Live
Channels after 21 Days All !!! Supervised
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Supervisory Microprocessor Cont.

• Where to From Here?
• Test Receiving LBT Bank
• Test Both Call Initiating and Call Receiving LBT
  Banks Simultaneously
• Convince NSF to Fund Prototype Development and
  Release to Science Community
• Build 20 Units And Release For Broader Testing

Graphics by Iridium
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• Single Channel ISU to ISU - Problems
  Discovered
• Non-DAV - Windows Applications and TCP/IP stack
  were not tolerant of the large time delays across
  the constellation
• Round Trip Ping Denver to South Pole (seconds)
• Low - 1.9 , Ave - 2.8, High - 10 (Non-DAV)
• Low - 0.9 , Ave - 1.3, High - 4.8 (DAV)
• Limited TCP/IP stack tuning was not effective
• DAV - Could Never Establish a Usable Connection
  due to
• LBT Firmware Error During DAV Connect Sequence
• Normal RING Mal-formed DAV RING
• ATA ATA
• CONNECT 2400 OK
• ltCRLFgt
• CONNECT 2400
• Windows Treats Mal-Formed Response As Fatal Error
  and Terminates Session

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Iridium Single Channel
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Short Burst Data
Graphics by Iridium
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SBD Test Objectives for Continuous
Operations Objective 1 Determine if a LBT has
been correctly provisioned for SBD Objective 2
Send SBD message in "Binary" mode Objective 3
Send SBD message in "Text" mode Objective 4
Receive SBD message Objective 5 Develop 10 day
reliability profile for sending SBD "Binary"
messages Objective 6 Once 5 is proven,
determine average time duration from send to
e-mail delivery Developed limited use
engineering software application to assist
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• This Application rides on top of the basic
  Iridium Test Utility
• Unattended auto SBD message generation
• Test different types of SBD functionality

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• SBD Test Results for Continuous Operations
• Auto-Generated SBD Message Sent Each Hour
• Test Date Messages/Run Status
  Recovery
• 01 03/09/2004 28 Non-Responsive
  Power Cycle
• 01 03/16/2004 47 Non-Responsive
  Power Cycle
• 01 03/26/2004 44 Non-Responsive
  Power Cycle
• 01 03/30/2004 04 Non-Responsive
  Power Cycle
• 01 03/30/2004 41 Non-Responsive
  Power Cycle
• 01 04/01/2004 86 Non-Responsive
  Power Cycle
• 01 04/05/2004 04 Non-Responsive
  Power Cycle
• 01 04/05/2004 23 Non-Responsive
  Power Cycle
• 01 04/06/2004 69 Non-Responsive
  Power Cycle
• 01 04/12/2004 19 Non-Responsive
  Power Cycle
• Average 36.5 Messages Before Failure

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End of Presentation Questions ???
Graphics by Iridium
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• Testing Continued - Chasing Ghosts
• The VAM Report It All the Users Fault
• RF Interference INMARSAT, as well as In-band
  Out-of-Band
• VHF RF Interference (110 Mhz to 190 Mhz)
  coupled onto the DC power supply lines
• Low Frequency (lt40 Khz) DC Power Supply
  Ripple
• Cabling Capacitance, Grounding, Shielding,
  Interference Transients
• A Month of Testing That Produced No Results
  Except to Prove That the Issues are Really LBT
  and/or Constellation Problems
• Report - No Mention of LBT and Constellation
  Issues !!!
• Help Received from Boeing and NAL