Change of GSM Network to Wireless Network

Hello kalai.selvan

Yes, that GPS is normally still trackable, unless inside a Faraday Cage.

Trust that assists you.

Kind Regards....

GPS signals and Wi Fi have nothing to do with each other. GPS is satellite technology and Wi Fi is computer router based. I believe thay are working on a WIFI wideband to transmit from a satellite, but they are not there yet.

GPS does not work well in big urban canyons like NYC. The GPS requires a direct view of at least 3 satellites. Inside, only if near a window facing the right direction.

GPS technology is based on communicating from device to satellite and needs a clear bath and is generally based on three satellite guidance methodology. It runs in trouble when one gets in urban big cities like New, York, London, Calcutta, Delhi Chicago and Boston. Big city has tall building and not able to catch signal and hence tracking system fails

Masyood

I guess i got your point. You want to track a person even inside buildings. So you are gonna have to deal with 2 different kinds of technology Gsm for global tracking and and local tracking inside buildings. Usually the information gathered inside buildings are private and are not shared publicly. And it would be impossible for you to get access to all the computers of every building that has a tracking system installed. Unless you want to be the pioneer of building such a system that would network all those individual systems together. But it would be a very hard task as there are different protocols and different systems that are not compatible with each other. Unless you come up with an international standard for tracking systems.

A gps/cellular link fixed in a human being where the cellular signal which is also trackable would help indoors.

Hi, kalai,selvan!

GPS is line-of-sight technology. If the GPS unit can't 'see' the satellites in the sky, it can't triangulate from them; and inside a building, it can't see the sky. So a GPS won't work inside a building.

If the building were to be constructed of glass, the GPS would work, depending upon the opaqueness of the glass caused by the number of glass layers between the GPS and the clear satellite view. One window --fine. Two windows, rarely any good. Three windows, probably useless.

GPS-to-Cellular systems also won't work inside a building because the GPS system still won't be able to see the satellites through the building walls and roof to transmit a person's/thing's location to a monitoring device via the Cellular network.

On the other hand, a cell phone doing monitored broadcasting can be triangulated by the frequency strength/number of repeaters picking up its signal. If the building were for example to be equipped with repeaters on four sides at its base, middle height, and roof line, a location could be determined for the broadcasting cell phone inside. However, dedicating the equipment necessary to maintain this kind of service would be quite expensive.

In order to track movement inside the building, the person/thing would probably most usefully require a transponder geared to building detection frequencies. In that case, one transponder system per floor might be enough, depending upon how location-accurate you wish to be.

Mark

I believe that you have two problems. First one is RECEIVING the signal from 3 satellites. The GPS device that you get from Radio Shack or wherever does no transmitting on its own. It takes the signal from the satellites, calculates the latitude and longitude and displays it and/or furnishes the information to a radio.

The second problem is getting the results to the central server. This could be as simple as writing down the latitude and longitude (from your GPS) on a slip of paper, handing it to the cowboy on the horse next to you and telling him to go... aka pony express. Or you might have a sophisticated radio transmitter which ties in directly to your GPS unit, and transmits to the receiver at your central server. The radio is the big variable. It would be quite different if you are traveling around the country, as opposed to wandering around an office building. With a wireless LAN environment, I would probably tie into the network using 802.11 protocol.

Trucks carrying hazardous materials can subscribe to a system in which they receive information from the GPS birds (satellites), calculate the latitude and longitude information, and retransmit this info (with any other pertinent information) to a communications bird, (which is different from the GPS birds), which relays the info to the central office.