Transcription
Measured Cellular Signal Strength Along AlaskaRoadways and Implications for Timely EMS Notificationand ResponsepM. Flanigan, A. Blatt, K. Majka (CUBRC)R. Perkins, B. Schuerman (AIPC)J. Sullivan (AKDOT&PF)Presented at2008 Rural ITS ConferenceSession E1Anchorage, AlaskaSeptember 3-5, 20081
Acknowledgementsg Alaska Highway Safety OfficeAKDOT&PFAK IPEMSNHTSAEMS Services (Air & Ground) & PSAPs in AlaskaDoug Lange (CUBRC)James Sheppard, Adrian Sandstrom (ZK Cell Test, Inc)2Photo courtesy of Beth Schuerman
Introduction Nationwide, rural roads are the site of:– 57% of fatal car crashes– 37% of all vehicle miles traveled1. In Alaska, 61% of fatal crashes are rural1. Increasingly, notification that a crash hasoccurred relies upon cellular phone systems.Fatal Motor VehicleCrash (MVC)– Voice calls (occupants or witnesses).– Data calls (in-vehicle Automated CrashNotification (ACN) systems). Accurate crash location information is alsocritical for rapid emergency systemresponse, especially in remoteareas with few landmarks.461 Fatal crashes in AK (2001-2006)161% (280) crashes rural39% (181) crashes urban1. Fatal crash geocoded data from the Fatal Analysis Reporting System (FARS) Database (2001-2006), developed by NHTSA NCSA.Vehicle Miles Traveled data from FHWA’s Traffic Volume Trends 2001-2006.3
AKEMSOSO ProjectojectAlaska Emergency Medical System Optimization (AKEMSO) Project– Research effort (funded by USDOT) supports Alaska's Highway SafetyOffice (AHSO) & Injury Prevention & EMS Section (IPEMS).– Objectives:j Support IPEMS efforts to standardize EMS data collection in Alaska(i.e., become NEMSIS compliant) and link with databases from AlaskaTrauma Registry and Alaska DOT&PF. Assess needs / requirements for GPS equipment in EMS & lawenforcement vehicles.Today’sTd ’SessionAlaska s current emergency response infrastructure & Examine Alaska’sprotocols to determine how responders can best exploit AutomaticCrash Notification (ACN) technologies, especially in rural areas.– ACN Systems: OnStar (GM), Tele Aid (Mercedes Benz), ASSIST(BMW) SYNC (Ford)(BMW),4
FocusocusFirst ProjectjStepsp Determine where along Alaska’s major roadways, the vehicle location &wireless communication technologies associated with ACN will perform asexpected.p Examine utility and benefits of ACN technology for crash victims as well aspublic safety and EMS responders.Two Presentations in this Session“Measured Cellular Signal Strength Along Alaska Roadways &Implications for Timely EMS Notification and Response”Response“Issues Associated with Motor Vehicle Crash Locations as Provided byACN Systems.”5
OutlineOute – Talka 1Measured Cellular Signal Strength &Implications for Timely EMS Notification and Response Automatic Crash Notification (ACN) OverviewCellular Systems in Alaska– Cellular Signal Strength Measurements– Signal Strength at/near Motor Vehicle Crash Locations¾ OnStar crashes¾ Fatal crashesImplications for EMS Response– Key Related National InitiativesSummary6
Automatic Crash Notification (ACN)7
ACN Components &Functional omponentsFrontSensorsGPS AntennaCellularAntennaSensor Diagnostic ModuleSideSensorsOnStarOSTelematicsModule Sense (& survive) crash Determine vehicle location / orientation Establish communicationsCustomerCall CenterInfrastructure9-1-1PSAP Cellular Network(phone call) Receive and display crashmessages Global PositioningSatellite ((GPS))System (lat / long) Confirm need for helpTodayPcrashhddatat andd Processprovide actionable information8
ACN FundamentalsTelematics Service Provider eCrashdataACN (1st Generation Systems) Automated crash message(triggered by an air bag deployment) Crash location (lat(lat, long)AACN (2nd Generation Systems)Possible voiceconnection thruTSP9-1-1PSAPEmergencyServices Automated crash message(triggered by an air bag deploymentor other above threshold event) Crash location (lat, long) Crash Delta Velocity Crash Direction Rollover (yes or no) Multiple impactsEstimated # ACN-equippedvehicles in Alaska 13,5009
Cell Phone Providers in Alaska &Equipment to Measure Cellular Signal Strength10
Cell Phone Providers & Technologiesi AlaskainAl kMajor Wireless Provider in AlaskaTechnologyPhoneAlaska Communication Systems (ACS)CDMAMotorola KRZRGCI / Cellular One / AT&TGSMNokia 6125 OnStar utilizes CDMA cell phone technology in their ACN systemsystem.¾ Contracted with ACS to provide wireless service for subscribers in Alaska.gy also important GSM technology¾ Witnesses or passers-by may attempt to report a crash using a GSM phone. Measurements of digital cellular signal strength undertaken for each technology.11
ZK-SAM Equipment Selected toMeasure Digital Cellular Signal StrengthEquipment used by cell phone vendorsMajor Components Display ZK-SAM Controller GPS Antenna Two Cell PhonesIn-Vehicle Power Cigarette Lighter12
Equipment Packaged for TransportAlong Alaskan Roadways Selection, packaging & initial checkout performed at CUBRC. First extensive measurements alongg the Alaska Highwaygy Systemy(by AIPC collaborators) began in May 2008 Focus on measuring control channel signal strength.13
Our AIPC Road Team14
C ll l SignalCellularSil StrengthStth Measurements.MtRoute Taken & Results15
Route where Measurements Collected AlongAlaska Highway SystemAlaska’s geographic area equals 21% of area of lower 48 statesbut major highways are relatively few. BarrowData collected along 2000miles of roadway¾ AK Highway System &selected main arterials(Anchorage, Fairbanks)Nome¾ May - Aug 2008FairbanksAnchorageJuneau Route highlighted in yellow. Heartbeat message every30 seconds confirmedequipmentit working.ki¾ Critical in areas whereno cell signal detected.16
Received Signal Strength Indicator (RSSI)on CDMA Control ChannelOnStar uses CDMAFairbanksNominal Signal QualityGreen Service PossibleaVery GoodAdequateMarginalRSSI (dbm)(db )( -89 to -38)( -99 to -90)(-105 to -100)NO SERVICE (Heartbeat detectedbut No Cell Service)No Service Reasonable coverageg alongghighways. Anchorage & Fairbanks havegood signal.See Expansion Segment ‘a’ possibleinstrument anomaly. Revisit.MilesAnchorage0 10 20406080 At resolution shown, pointsare 3 miles in diameter. Mayobscure small ‘no signal’17areas. Expand
SERVICE vs NO SERVICE in CDMA Control ChannelExpanded View of 10 mile stretch along N.N Glenn HighwayHighway.N. Permanenti Rd0123 MilMiles¾ Circled areas have several datapoints ( ) with heartbeatbut no cellular service.18
Phone Calls Placed in ‘Low RSSI’ AreasHighway between Palmer and Moose CreekX-97-105XX Low RSSI levels measuredalong stretch of Glenn HWY(Rt. 1) between Palmer &Moose Creek. AIPC staff returned to theseareas and attempted to placephone calls.X-101-98X -103X -102X -103X -105X -104X-102X -94––X CallC ll LLocationti 3 of 11 calls failed. Failedcalls had RSSI in ‘Marginal’category.–11MileMileGreen X call successful.Black X call failed.fRSSI measured -104 or-105 at these locations.19
Estimated Percent of Route along AlaskaHighwaygy ‘Ring’g with Indicated SignalgQualityyPossibleEquipmentProblemCDMA Route Length (outside oflarge cities) 2,173 miles.No Signal Estimated percent of routewith indicated signal level.42 %41 %6%11 %Very Good(-89 to -38)Adequate(-99 to -90)Marginal((-105105 to -100)100)No Signal (or possibleequipment problem.)20
Alaska OnStar Crash Reports in 200821
Alaska CARS Data Systemy CARS (Condition Acquisition and Reporting System) is a web-basedsystem with critical roadroad, traveltravel, weather and traffic informationinformation.– At least 10 states have deployed CARS; Alaska is one of them. CARS is of interest to the AKEMSO project, because it receives OnStarcrash reports in near real time. In Dec 2007, AKDOT provided CUBRC with a link to the Alaska CARS xmlwebpage CUBRC programmers created software to monitor the CARSwebpage.data postings for Alaska, and identify & store OnStar crash alerts. Over a 27 week period in 2008, there were 23 OnStar calls entered intoC SCARS.22
OnStar Crash Locations Overlaid onMeasured Cellular SignalgStrengthgWasillaPalmer CARS OnStar crash eventsprovide a form of ‘truth data’by demonstrating whereACN cellularll l callsll weresuccessfully completed. Thus far, OnStar crashes allin areas with measured RSSIvalues in ‘Adequate’ to ‘VeryGood’ range.Cook Inlet
Measured RSSI in Vicinity ofSelected OnStar Crash LocationsSorted byy distance (m)( ) between OnStar crash location and RSSI data location.Nearest Cellular MeasOnStar crashes automatically entered into CARSEvent IDEvent 2008serious 9.00‐82.00‐92.00‐61.0061.00‐71.00Dist 6.87Locations plotted on preceding map.24
Fatal Motor Vehicle Crash Locations Provide LargerSample of Serious Injury Crashes in Alaska25
Fatal Crash Locations from FARS 2001-2006Overlaid on Cellular Strength MapFatal Crash Location The 405 geocoded fatal crashlocations in FARS provides arepresentative spatialdistribution of serious injurycrashes.¾ For every fatal crash, typicallyabout 5 serious injurycrashes. 176 fatal crashes (43%)occurred on or near routedriven with ZKSAM.26
Why is ACN so important for Alaska?Implications for EMS Response27
Utility and Benefits of ACNfor Emergency Medical Response Nationwide FARS data shows that 50% of fatal crash victims die at scene oren-route to hospital.– Immediate notification with accurate crash location information can help speed EMSresponse to crash scenes & likely reduce these statistics.– Sizeable fraction of past Alaska fatal crash sites in areas where ACN calls will likelysucceed. Specific crash information with accurate location can also help reduce exposureoff publicbli safetyf t andd EMS respondersdtto hhazardousdweatherth andd roaddconditions. Future sharing of ACN alert with secondary recipients (e.g., nearest air medicalbbaseandd surgicali lhhospital)it l) can hhelpl expeditedit crashh victimi ti access tto ddefinitivefi itisurgical care.– Parallel notification can allow air medical pre-flight and warm-up to begin.– Early alert can also enable trauma team preparations to begin, even as firstresponders traveling to scene.scene28
Level of Emergency Medical Care Availablein Alaska by Community TypeCommunity TypeEMS Level of CareNo. of FatalCrashes2001-2005% of TotalCrashesI – Isolated Village/Highway VillageCommunity clinic with a CHA or EMT9825%II – Isolated SubregionalilCCommunityitCommunity clinic with PA, NP or physician;h lth care serviceshealthiprovideid bby publicbli orprivate sector12332%III – Large Town orRegional CenterCommunity hospital & physicians; healthcare service agencies include both public &private sector339%IV – Small CityHospital with 24 hr ED & full continuum ofcare; multiple providers of health care &other services including both public & private4812%V – Urban CenterSome specialized medical & rehab servicesfor low incidence problems.8322%385100%TotalCHA Community Health Aide; NP Nurse Practitioner; ED Emergency Dept.Over 55% of the Alaskan fatal crashes occur in communities without a community29hospital. Rapid notification & optimized transport is therefore critical.
Alaska Emergency Medical ResponseI f tInfrastructuretGeographic Information System EMS Responder Locations- Ground Ambulance- Air Medical Hospitals-Trauma Center- Acute Care HospitalsH Trauma Center (L2)H Acute Care HospitalGround Ambulance BaseAir Med Rotor Wing (RW) Basewith 10 min Fly Circlewith 20 min Fly CircleAir Med Fixed Wing BaseAlaska HighwaygyPrincipal Arterial30
Related National InitiativesNext Generation 9-1-1 NHTSA initiative to establish national architecture and transition plan forth NG 9the9-1-11 1 system.tWill enablebl ttransmissioni i off ttextt & datad t (e.g.,(ACN)as well as images and video along with voice into the 9-1-1 system. Statewide network projects are underway as well as smaller scale demosNew and Emerging Technologies 9-1-1 Improvement Act Signed into Law 7/23/2008 Intended to promote and enhance public safety by facilitating the rapiddeplo ment of IPdeploymentIP-enabledenabled 911 and Enhanced 99-1-11 1 serservicesicesCDC Field Triage Medical Protocol for Vehicle Telematics Revised ACS COT1 field trauma triageg gguidelines include considerationof vehicle telematics data. Developing recommendations on how to best use the telematics crashdata to support dispatch and triage decisions.1. ACS COT American College of Surgeons Committee on Trauma31
Summary Transmission of an ACN alert requires successful placement of anautomatic cell phone call. To determine where ACN systems can communicate along the AlaskaHighway System, CDMA cellular signal strength was measured.– 83% of highway system measured had adequate to very good cellular signal– Areas with marginal or ‘no service’ were identified.– In general, CDMA reception was geographically more extensive than GSM. OnStar crashes are now being extracted in near real time from the AlaskaCARS system and compiled into an ACN crash database. These dataprovide a form of ‘truth’truth data by demonstrating where ACN calls weresuccessfully completed. FARS crashes have been mapped to illustrate where serious injury crashesare occurring in Alaska. Over 55% of the Alaskan fatal crashes occur incommunitiesiti withoutith t a communityit hhospital.it l RapidR id EMS notificationtifi ti&optimized transport to distant medical care is therefore critical.– This argues for making ACN alert available in real time to nearest air med base &hospital.32
Introduction Nationwide, rural roads are the site of: - 57% of fatal car crashes57% of fatal car crashes - 37% of all vehicle miles traveled1. In Alaska, 61% of fatal crashes are rural1. Fatal Motor Vehicle Crash (MVC) Increasingly, notificationthat a crash has occurred relies upon cellular phone systems. - Voice calls (occupants or witnesses).
