the open location services (ols) tracking service standard

OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY

The Open Location Services (OLS) Tracking Service Standard

Dr. Johnny Tolliver

Oak Ridge National Laboratory

Goeff Hendrey

Telcontar

Carl Stephen Smyth

Mobile GIS


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


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


Tracking Components

MobileTracking

Client

TrackingService

TrackingDisplayClient

Locationdata

Request/responsefor location data


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


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


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


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 doesn’t 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


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


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 555-555-1234 Retrieve a list of all tracked mobile phones within

500m of (X,Y) at present time Forward position updates for phone 555-555-1234

to a specified URL


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


Google Earth Demo

Live demo, if network available and phones are online

Static photo if not


Google Earth Demo


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

the open location services (ols) tracking service standard

Documents