Location meets social networking

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Location meets social networking

• Larry Magid
• co-director, ConnectSafely.org
• founder, SafeKids.com

larry_at_larrymagid.com
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Location-Based Services

• A service that depends on the network knowing
  your location
• Examples include
• Emergency 911
• Navigation
• Vehicle Assistance (OnStar)
• Child Finder
• Advertising
• Local Search
• Traffic applications
• Automotive Vehicle Location (Fleet tracking)
• Asset Tracking
• Personnel Tracking
• Social Mapping
• Self Guided Tours
• Finding elderly or individuals with Alzheimers

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Estimated size of LBS market

• At least 750 Million in 2007 US Canada
• Estimated to grow by at least 75 to 100 next two
  years
• Estimates include WiFi but not RFID
• Source David H. Williams LBS Globe.com, E911
  LBS Consulting

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Why phones have location capability

• The Federal Communication Commissions Enhanced
  911 Rules
• Phase 1 requires carriers, upon valid request by
  a local Public Safety Answering Point (PSAP), to
  report the telephone number of a wireless 911
  caller and the location of the antenna that
  received the call.
• Phase II requires wireless carriers to provide
  far more precise location information, within 50
  to 300 meters in most cases.

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Technologies used

• GPS (Global Positioning System)
• 24 satellites in orbit. Typically 5 to 8 are
  visible from any one place
• Device gets fix by triangulating position of
  satellites.
• Distance calculated by time it takes for signal
  to travel from satellite to receiver. Calculating
  the time it takes from 4 satellites provides an
  accurate fix.

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Regular GPS vs. AGPS

• Regular GPS is fine when youre in the clear
  with a strong battery, powerful receiver and a
  line-of-sight view of the sky. But indoors and
  with less powerful systems, you need an assist.
  Another problem is TTFF (Time to First Fix).
• AGPS (Assisted Global Position System)
• The receiver communicates with an assistance
  server that helps calculate position using GPS
  coordinates and possibly other data such as
  distance from cell phone tower(s). Computations
  may take place on remote server.

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Extra data from the networks

• AGPS systems can also download map data, points
  of interests and other data on demand even to a
  device with limited storage capacity.
• Telenav for example can plot gas stations based
  on gas prices.

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Triangulation

• Triangulation (also known as trilateration) uses
  the known locations of two or more reference
  points, and the measured distance between the
  subject and each reference point.

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Positioning relative to cell towers

• Whenever any device is in contact with a cell
  tower, its possible to determine which tower
  and, therefore, the approximate location within a
  general radius.
• When it can receive data from two towers, the fix
  is more accurate but still approximate.
• Three or more towers provides a reasonably
  accurate fix.

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1 Point Rough idea
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2 Points Aproximate
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3 Points Accurate fix
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Fancy Math Triangulation Off Cell Towers

• U-TDOA (Uplink Time Difference of Arrival )
  technology locates by comparing the time it takes
  signal to reach several Location Measurement
  Units installed at base stations. Accurate to
  within 50 meters. (www.3g.co.uk)
• Advanced Forward Link Trilateration (AFLT)
• Does not use satellites but phone takes time
  distance measurements from nearby towers (ideally
  at least 3) to determine location
• Sam Altman, Founder Loopt

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WPS Wifi Positioning System

• Skyhook Wireless has been driving the country
  mapping out WiFi hotspots in top 2,500 cities.
  Has database of gt 16.5 million access points,
  public private encrypted.
• A device can get a fix from a WiFi hotspot
• Increasing number of handheld devices including
  Skype Phones can access WiFi systems

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Wi-Fi works best in dense urban areas
Source Skyhook Wireless
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AIM applications
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Geo Tagging
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Self-Reporting

• Users tell the system where they are and/or what
  they are doing

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Short distance technologies

• RFID Now used to track assets. Could be used
  in hospitals to track patient movement within
  facility
• Ericssons Bluetooth Local Infotainment Point
  (BLIP). Download coupons as you walk near a BLIP
  device

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Technology is neutral, uses arent

• Like many technologies, location-based services
  have an enormous potential for good but they can
  also be misused.
• The potential for misuse doesnt invalidate the
  technology, but it does mean that we must be
  thoughtful about how we apply it, especially
  during its developmental stages.

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Please join us in the online safety communitys
forum for mobile fixed social networking.
Larry_at_ConnectSafely.org Anne_at_ConnectSafely.org