-Based ServicesEverywhere You Go"> To improve its location tracking for mobile devices, Autodesk developed a cell-network-assisted GPS system. GPS is the preferred method because it is cheaper and traditionally more accurate. But when the satellite signal is not available, carrier networks can rely on cell tower triangulation technologies such as AFLT (Advanced Forward Link Trilateration), EOTD (Enhanced Observed Time Difference), UTDOA (Uplink Time Difference of Arrival) and TDOA (Time Difference of Arrival).Although Lohtia said Autodesk tries to go out of its way to find a customers location wherever possible, constant reporting on a mobile employees whereabouts is not always necessary. The accuracy and timeliness of location information depends on the application, Lohtia said. For a taxi dispatch service, for example, constant "real-time-accurate within a few meters" location information is extremely valuable. But a consumer application that recommends a nearby restaurant does not need to be as accurate or timely. Such requests could be gathered on demand and be accurate down to a cell area. Shifting data demands depending on application lessens the need for constant requests making data traffic more manageable. Ultimately, Autodesk wants to impact every application with location, Lohita said. "Every action you take on your cell phone, location will become a part of it," said Lohtia. "Itll be so transparent. People wont even know theyre using location-based services." Location-Enabled Applications Verizon Wireless newly released Traffic Connect Service may soon be the first consumer application to take advantage of Autodesks location technology. The traffic monitoring service sends text alerts to mobile phones when theres a traffic issue on the users commute. The service does not currently track the phones location. Locations are predetermined by filling out a commute form with drive time and drive location on vtext.com. Although Verizon wouldnt confirm if theyll be using Autodesks technology, the two would seem to complement each other well. Given the mobile carriers claim that the application is successful without Autodesks location technology, Doug Busk, associate director of messaging at Verizon Wireless, of Bedminster, N.J., said, "It goes to show that the strength of a location-based service is in the application itself as much as it is in knowing the users location at that exact time." While the location information was valuable, "They were looking to do more than just track them," said David Almoslino, @Roads director of marketing communications. Almoslino said he remembers customers asking such questions as "Can we monitor the service and maintenance and operation of the vehicle itself?" and "Can we manage the information flow in real time between these field technicians and headquarters?" From these customer desires, @Road cranked up its offerings by converting simple GPS location devices into 802.11b hot spots. The new offering, @Road Mobile HotSpot, turns a trackable truck into a wireless network. This coupling of GPS with a wireless WAN opens up endless possibilities. Applications you run on your network can reach your field force wherever they are. Theres no need to be tethered to the truck. Technicians can be in the customers location and see what they have. With a mobile information device such as a PDA, they can request information such as supplies or process orders. "They become a more sophisticated representative of the company there on the spot," said Almoslino.APCs InfraStruxure Express mobile data center can deliver power and Internet connectivity when there are no other options. Click here to read more. "That could translate into increased productivityone more job thats going to get done in the field. That really translates into real revenue," said Tam. Although Autodesk and @Road use different technologies to supplement GPS, they both started with the realization that GPS alone cannot achieve mobile resource management or advanced location-enabled applications. While combinations of these technologies can greatly empower applications, most are highly reliant on mapping data. Providers covering cities such as Boston, New York and Washington can deliver excellent information. Those in more rural areas are not as fortunate. As Verizon Wireless Busk discovered with the implementation of the Traffic Connect Service, "No location-based service can succeed without high-quality, relevant and timely information behind it." David Spark is a freelance writer in San Francisco. Contact him at firstname.lastname@example.org. Check out eWEEK.coms for the latest news, reviews and analysis on mobile and wireless computing.
Each technology, which operates on a different network, takes time/distance readings between the handset and three or more cell towers to approximately locate the signal-sending handset.