National Flood WorkshopHouston, TexasOctober 2010
Don Van Wie, Telos ServicesR. Chris Roark, Blue Water Design, LLC
ALERT2 Concentration Protocol is in production in Overland Park/KCMO for repeater-to-base path
ALERT2 is operating in parallel with ALERT on repeater-to-base leg in Urban Drainage and Flood Control District
UDFCD: ALERT v ALERT2 side-by-side comparisons 8 months, 2 million ALERT messages analyzed
Overland Park: Logging at repeater sites permits exact determination of ALERT2 losses Early June storms with partial logging Full month analysis for September 2010
Demonstrate reliability of hardware in normal operating environment
Quantify the relative performance of ALERT/ALERT2
Verify or and adjust the operating parameters based on operations at a production scale
No hardware failures ALERT2 data loss “over the air” is typically
less than 5 reports per 10,000 over any path that is suitable for ALERT
Relative ALERT2 performance improves as traffic rates increase
RF-only Preamble has been extended 55 msec
Slot variance study shows 0.5 second slots are possible
10 BWD Modulator/Encoders 6.5 years of unit time accumulated
4 BWD Demodulator/Decoders 4.75 years of combined operation
About half of equipment is in unconditioned environment
NO Failures!
Data Composition and Summary Statistics
Repeater Start Date ALERT Records ALERT2 Records Difference (A2-A) % Difference
Blue Mountain 8/1/2010 328,319 334,064 5,745 1.75%
Smoky Hill 2/23/2010 771,716 781,508 9,792 1.27%
West Creek 2/23/2010 478,256 489,544 11,288 2.36%
Lee Hill 4/9/2010 178,764 183,148 4,384 2.45%
Gold Hill 5/10/2010 250,250 261,083 10,833 4.33%
Total
2,007,305
2,049,347 42,042 2.09%
ALERT ALERT2
Repeater Sample Missed by Alert % Missed by %
Alert Errors Lost Alert2 Lost
Blue Mtn 25,000 445 1 1.78% 1 0.004%
Smoky Hill 25,000 149 0 0.60% 4 0.016%
Gold Hill 25,000 966 5 3.88% 5 0.020%
75,000 1,560 6 2.08% 10 0.013%
Summary of September 1-28, 2010
Tx From: Johnson Co Blue ValleyCentury
Twrs Totals/Avg Rpts Sent 72678 101091 120940 294709
OP City Hall Lost Rpts 2326 2785 2774 7885 % Loss 3.20% 2.75% 2.29% 2.68%
Fire Training Cntr Lost Rpts 31 75 21 127 % Loss 0.04% 0.07% 0.02% 0.04%
To eliminate false setting by anomalous readings: Limit correction based on plausible drift rate Lengthen time in lock before taking readings
Lengthened preamble affects capacity Affects first block only Impact diluted as traffic increases
Size of required deadband controls available slot time; 100 msec will be adequate 500 msec slots can be used for most gage sites Capacity of 1 channel is 120 gages, 331 KBytes/
hour 2 sec slot (repeater) can carry 630 Kbytes/hour or
157,500 ALERT Messages
Ready for new ALERT Concentrator applications
Low power repeater for 2011
Vendors are working on gage applications
Implementation of Protocol Application layer
Thank you
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