Cell Phone Location Systems

There are several types of location systems built into cell phones.

• Observed Time Difference of Arrival (OTDOA)
  • Used in 3G networks
  • resolution: 100m
  • low latency
  • available wherever a location-enabled cell signal is available
• GPS
  • resolution: 1m
  • avaialble outside everywhere – as long as the satellites are not shadowed by buildings, trees, etc
  • low latency except that initial aquisition of the GPS signal can take minutes

External Vendors

• CPS
  CPS creates chips and software trechnologies that support location services in cell phones. The are planning to create a location system chip with OTDA and GPS capability that will OEM for $1. See: E-GPS.