I recently purchased a typical U.S. Cellular phone, and got confused information from the sales person about its GPS function. In order to get the straight scoop, I visited the local 911 operator at the state police (who pick up all the 911 calls in our area). He demonstrated the system for me by calling 911 from my phone. The phone used GPS to accurately describe its position to the operator. Since we were INSIDE the building, I was impressed. My handheld Garmin likes being outside. What this means is that cell phones now "know" where they are at by GPS signals, regardless of whether they can transmit this info (by being near a system tower). There are two positions for the "location" selection on the phone menu: (1) "location on" (here your location -- latitude and longitude -- are transmitted every time you call, and can be received by anyone you call that has the specialized equipment), and (2) "E911 only" (here your position is transmitted only when you make a 911 call). Missing is the menu selection that would tell ME where I am -- right on my phone screen. Does anyone know if position information can be got out of cell phones by bypassing the menu? Wouldn't it be nice if the phone companies added the option of reading position info on the phone screen? I consider most of their extra features frivolous. In order to avoid inadvertently connecting to the internet (and paying substantial download fees before even getting started), I had to go to the local phone store to get them to block this feature.
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It is not actual GPS
as I understand it. I could be wrong but the best information I have gotten suggests to me that the "GPS" information on cell phones is not received from the usual GPS satellites. That is why it will work in a building where a normal GPS receiver will not work. I believe that location information is generated by and within the cell system itself. They do a sort of cell tower triangulation by measuring your cell phone signal strength at various towers. That gives them a few known bits of data which they can use to figure your position. If you have your cell phone turned on, the phone company already knows fairly accurately where that phone is located. That is how they found OJ when he tried to run. You do not need to be actually using the phone for this to work. It only needs to be turned on. I have asked verizon and sprint about this and they cannot tell me for certain how the "GPS" features work. I doubt the people I spoke to even know what real GPS is. Maybe someone else more knowledgable on this topic can enlighten us all.
as I understand it. I could be wrong but the best information I have gotten suggests to me that the "GPS" information on cell phones is not received from the usual GPS satellites. That is why it will work in a building where a normal GPS receiver will not work. I believe that location information is generated by and within the cell system itself. They do a sort of cell tower triangulation by measuring your cell phone signal strength at various towers. That gives them a few known bits of data which they can use to figure your position. If you have your cell phone turned on, the phone company already knows fairly accurately where that phone is located. That is how they found OJ when he tried to run. You do not need to be actually using the phone for this to work. It only needs to be turned on. I have asked verizon and sprint about this and they cannot tell me for certain how the "GPS" features work. I doubt the people I spoke to even know what real GPS is. Maybe someone else more knowledgable on this topic can enlighten us all.
I Work in the test lab for the E911 application
I am responsible for certifying the entire E911 system for a telecom company. The Wireless E911 location service has several methods with which it gives a fix. A high precision fix <11 meters accuracy and a Low precision fix =1009 meters accuracy. When your cel phone sends a high precision fix, it is getting it's fix from multiple satelites, coming into the cel network on a WARN feed. When that is not possible, you report a low precision fix which comes from the cel/sector data. Which means which cel tower you are at, and which antenna you are serviced by. I hope this helps.
BTW, turning off your GPS functionality does NOT stop emergency services from locating you. In fact, even if you are not on a call, in most instances, we can do an idle mode query and find you. Some phones still choke on the idle mode query, but not all. Tim
I am responsible for certifying the entire E911 system for a telecom company. The Wireless E911 location service has several methods with which it gives a fix. A high precision fix <11 meters accuracy and a Low precision fix =1009 meters accuracy. When your cel phone sends a high precision fix, it is getting it's fix from multiple satelites, coming into the cel network on a WARN feed. When that is not possible, you report a low precision fix which comes from the cel/sector data. Which means which cel tower you are at, and which antenna you are serviced by. I hope this helps.
BTW, turning off your GPS functionality does NOT stop emergency services from locating you. In fact, even if you are not on a call, in most instances, we can do an idle mode query and find you. Some phones still choke on the idle mode query, but not all. TimThank you, Tim
It is really nice to get an informed answer on this topic. The people I have talked to do not have a clue. By what you said, I guess that the so called GPS enabled phones do have some actual GPS capability. I take that to mean that there is a GPS receiver contained within it. That sounds like good news to me. Am I correct? Is there any practical way to get your actual lat/lon from the cell phone itself? Will this require a phone call? I would like to be able to simply read it from the display just like my Garmin. If I could send it via Bluetooth to my Ipaq that would be even better. Is that possible presently? Do you know of any particular phone you would recommend for this purpose? My old Motorola V120 is getting very tired and I would like to replace it with something with more capability.
It is really nice to get an informed answer on this topic. The people I have talked to do not have a clue. By what you said, I guess that the so called GPS enabled phones do have some actual GPS capability. I take that to mean that there is a GPS receiver contained within it. That sounds like good news to me. Am I correct? Is there any practical way to get your actual lat/lon from the cell phone itself? Will this require a phone call? I would like to be able to simply read it from the display just like my Garmin. If I could send it via Bluetooth to my Ipaq that would be even better. Is that possible presently? Do you know of any particular phone you would recommend for this purpose? My old Motorola V120 is getting very tired and I would like to replace it with something with more capability.
GPS / Wireless 911
The phone certainly does have a real GPS. It does not have the capability of feeding it to the scrfeen or any other wireless device. The data is received, sent to a set of either Sun or HP Non-Stop servers, then goes through a long drawn out processes. The location is written to a log, which is readable by someone who subscribes to the location service. This service is now available to corporate America. It's a pretty awesome service. Now, on your question as to whether or not a phone call has to be made to obtain GPS fix. The answer is no. The system is capable of doing an "Idle Mode Query" It's basically a feature previously unused in the phone. The system wakes up the phone and tells it to obtain a fix and feed it to the system. As for phones? After much testing, I am a big fan of LGE products. But almost all of the phones use a Qualcomm chipset, regardless. However, you're not going to get a GPS readout with your phone for awhile to come. Maybe in 2006 or so. That's just a predioction on my part. But remember, telecom companies create what the customers want and need. Create a need, and we'll fill it!
The phone certainly does have a real GPS. It does not have the capability of feeding it to the scrfeen or any other wireless device. The data is received, sent to a set of either Sun or HP Non-Stop servers, then goes through a long drawn out processes. The location is written to a log, which is readable by someone who subscribes to the location service. This service is now available to corporate America. It's a pretty awesome service. Now, on your question as to whether or not a phone call has to be made to obtain GPS fix. The answer is no. The system is capable of doing an "Idle Mode Query" It's basically a feature previously unused in the phone. The system wakes up the phone and tells it to obtain a fix and feed it to the system. As for phones? After much testing, I am a big fan of LGE products. But almost all of the phones use a Qualcomm chipset, regardless. However, you're not going to get a GPS readout with your phone for awhile to come. Maybe in 2006 or so. That's just a predioction on my part. But remember, telecom companies create what the customers want and need. Create a need, and we'll fill it!
Thanks
Thanks Tim, So my phone doesn't "know" where it is -- it just sends raw satellite data to a server, which figures out where it is. BTW, if each new car had one of these built in, they would not only know where you were, but how fast you were going and whether you stopped at all the stop signs. When I made this observation to my son in law, he added that they could also add a machine right in your car that would dispense traffic tickets on the spot.
Thanks Tim, So my phone doesn't "know" where it is -- it just sends raw satellite data to a server, which figures out where it is. BTW, if each new car had one of these built in, they would not only know where you were, but how fast you were going and whether you stopped at all the stop signs. When I made this observation to my son in law, he added that they could also add a machine right in your car that would dispense traffic tickets on the spot.
Mine displays coordinates
I have a Motorola i530 that displays my GPS coordinates... I never used it for such as it's my business cell so I don't take it on the boat with me.
I have a Motorola i530 that displays my GPS coordinates... I never used it for such as it's my business cell so I don't take it on the boat with me.
Some do
Some phones know where they are, and have full GPS capabilities. Some phones have Palm Pilots. Heck some phones have televisions now LOL. But, does the consumer want to pay for it? In a year or so the stuff will be affordable. For the most part, the phones get a fix from the satelites, send that data to the tower, which sends it to the system, which spits it out to the service owner (emergency operator, or business owner).
Some phones know where they are, and have full GPS capabilities. Some phones have Palm Pilots. Heck some phones have televisions now LOL. But, does the consumer want to pay for it? In a year or so the stuff will be affordable. For the most part, the phones get a fix from the satelites, send that data to the tower, which sends it to the system, which spits it out to the service owner (emergency operator, or business owner).
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