The Open Location Services OLS Tracking Service Standard

1
The Open Location Services (OLS) Tracking Service
Standard

• Dr. Johnny Tolliver
• Oak Ridge National Laboratory
• Goeff Hendrey
• Telcontar
• Carl Stephen Smyth
• Mobile GIS

2
Open Location Services

• AKA OpenLS (or just OLS)
• A component of the Open Geospatial Consortium
  (OGC)
  
• Interested in creation, promotion, and use of
  international standards for location services of
  all kinds
  
• The location service topic of this talk is the
  OLS Tracking Service

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What is Tracking?

• Tracking can mean different things to different
  people
  
• For the purposes here, tracking means all the
  components necessary to produce near-real-time
  moving dots on a map corresponding to tracked
  vehicles, people, assets, etc.
• The tracking service is the middle-tier service
  component that facilitates tracking

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Tracking Components
Tracking Service
Request/response for location data
Location data
Mobile Tracking Client
Tracking Display Client
5
Short History and Motivation

• ORNL has a program called SensorNet
• SensorNet has a major testbed deployment at Ft.
  Bragg, NC
  
• Ft. Bragg needed to track emergency response
  vehicles and personnel
  
• ORNL offered to do a pilot tracking test using
  Nextel cell phones with GPS

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Cell Phone Tracking

• Most cell phones know where you are
• Only Nextel provides an accessible API that
  permits user plane retrieval of location
  information
  
• We used the Nextel/Motorola Location API to
  obtain GPS coordinates of the phone and uploaded
  to a server
  
• No rocket science here, many other have done the
  same thing
  
• Then displayed moving dots on a Keyhole (now
  Google Earth) map

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Did Not Want a Proprietary System

• ORNL tracking server and display client were
  completely proprietary
  
• We desired a standard way of uploading and
  downloading location information
  
• Standards reduce costs
• Promote competitive commercial implementations
• No long-term software maintenance issues for the
  National Lab

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Needed a Standard

• No such existing standard for tracking was
  identified
  
• NMEA exists for GPS location information
• Most (all?) GPS receivers can output
  NMEA-formatted data
  
• Several software solutions can use NMEA data for
  mapping applications
  
• But NMEA doesnt really address the same issues
• Thus was born the OLS Tracking Service
• Created and implemented during the OGC OWS-3
  testbed during Summer of 2005

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What is the OLS Tracking Service?

• An XML web service interface specification for
  tracking data
  
• Any standard-compliant mobile tracking client can
  upload tracking data to the server
  
• Any standard-compliant tracking display client
  can retrieve location data from the server for
  display
  
• Different and competing commercial service
  implementations and client implementations will
  interoperate
  
• Includes location privacy, historical queries,
  geographically bounded queries, etc.
  
• And, of course, current position queries
• Also supports service chaining for location push
  rather than pull

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Example Interactions

• Update the current location of a mobile phone
  i.e., upload location
  
• Retrieve the current location of a mobile phone
• Retrieve the last 10 locations within 500m of
  (X,Y) for mobile phone [phone]
  
• Retrieve a list of all tracked mobile phones
  within 500m of (X,Y) at present time
  
• Forward position updates for phone [phone]
  to a specified URL

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ORNL Draft Implementation

• Created as part of OWS-3
• Implemented much, but not all, of the proposed
  standard
  
• Used during the OWS-3 Demo in October
• Display clients appear in OWS-3 demo movie

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Google Earth Demo

• Live demo, if network available and phones are
  online
  
• Static photo if not

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Google Earth Demo
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Google Earth Demo
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Status

• Initial OLS Tracking Service is released as an
  OGC Discussion Paper for public comments
  
• Working its way toward OGC adoption as a
  standard
  
• Will be enhanced/matured in OWS-4
• Improvements to draft ORNL implementation
• Fine tuned, hardened, more testing
• Perhaps open-sourced
• Service interface to be evolved if needed