cell phones and location fixing

As a general statement I dislike cross posting, but I will for this
query since it allows me to look at several knowledgable people at once
in both the cellular and ems communities.

Our E911 system just upgraded to allow cell towers to give an
approximate location for a cell call. The one question I couldn't get
an answer to was how the location was located.

I'm familiar with triangulation where tower one notes it is on the A
side of the triangle antenna array which covers 0-120 degrees. Tower 2
sees it off the C side covering 240-360. This is a pretty wide area
since our cell towers are a good distance apart in a rural area.

Do they also ping the cell phone to get a distance measurement? Is this
used to help narrow the error circle?

Thanks in advance for the help.

MAH

---

› See More: cell phones and location fixing

mah <[email protected]> writes:

>As a general statement I dislike cross posting, but I will for this
>query since it allows me to look at several knowledgable people at once
>in both the cellular and ems communities.

>Our E911 system just upgraded to allow cell towers to give an
>approximate location for a cell call. The one question I couldn't get
>an answer to was how the location was located.

There are 2-3 schemes. Most generally, you know which antenna on a
given cell is in use. From 2 cells, you can get a area.

More exact schemes use in effect ping timing; you are 3 ms from Cell
34D, 4 ms from Cell 56Q, and 6 ms from Cell 66R; where are you?
But it appears this scheme is not fulfilling the FCC specs. Installing
a GPS rx in each phone is the alternative.

--
A host is a host from coast to [email protected]
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

mah <[email protected]> writes:

>As a general statement I dislike cross posting, but I will for this
>query since it allows me to look at several knowledgable people at once
>in both the cellular and ems communities.

>Our E911 system just upgraded to allow cell towers to give an
>approximate location for a cell call. The one question I couldn't get
>an answer to was how the location was located.

There are 2-3 schemes. Most generally, you know which antenna on a
given cell is in use. From 2 cells, you can get a area.

More exact schemes use in effect ping timing; you are 3 ms from Cell
34D, 4 ms from Cell 56Q, and 6 ms from Cell 66R; where are you?
But it appears this scheme is not fulfilling the FCC specs. Installing
a GPS rx in each phone is the alternative.

--
A host is a host from coast to [email protected]
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

David Lesher <[email protected]> wrote in
news:[email protected]:

> More exact schemes use in effect ping timing; you are 3 ms from Cell
> 34D, 4 ms from Cell 56Q, and 6 ms from Cell 66R; where are you?
> But it appears this scheme is not fulfilling the FCC specs. Installing
> a GPS rx in each phone is the alternative.
>

And has already been started by nextel, and perhaps others.


john

David Lesher <[email protected]> wrote in
news:[email protected]:

> More exact schemes use in effect ping timing; you are 3 ms from Cell
> 34D, 4 ms from Cell 56Q, and 6 ms from Cell 66R; where are you?
> But it appears this scheme is not fulfilling the FCC specs. Installing
> a GPS rx in each phone is the alternative.
>

And has already been started by nextel, and perhaps others.


john

On Thu, 06 Nov 2003 16:41:59 -0600, mah <[email protected]> wrote:

>As a general statement I dislike cross posting, but I will for this
>query since it allows me to look at several knowledgable people at once
>in both the cellular and ems communities.
>
>Our E911 system just upgraded to allow cell towers to give an
>approximate location for a cell call. The one question I couldn't get
>an answer to was how the location was located.

The following may prove to be of interest:

http://www.it.cityu.edu.hk/~hcso/icassp03_1.pdf

--
When I die, I want to go peacefully in my sleep like my Grandfather did -
not screaming like the passengers in his car.

On Thu, 06 Nov 2003 16:41:59 -0600, mah <[email protected]> wrote:

>As a general statement I dislike cross posting, but I will for this
>query since it allows me to look at several knowledgable people at once
>in both the cellular and ems communities.
>
>Our E911 system just upgraded to allow cell towers to give an
>approximate location for a cell call. The one question I couldn't get
>an answer to was how the location was located.

The following may prove to be of interest:

http://www.it.cityu.edu.hk/~hcso/icassp03_1.pdf

--
When I die, I want to go peacefully in my sleep like my Grandfather did -
not screaming like the passengers in his car.

In alt.cellular John P Vassel <[email protected]> wrote:
> David Lesher <[email protected]> wrote in
> news:[email protected]:
>
>> More exact schemes use in effect ping timing; you are 3 ms from Cell
>> 34D, 4 ms from Cell 56Q, and 6 ms from Cell 66R; where are you?
>> But it appears this scheme is not fulfilling the FCC specs. Installing
>> a GPS rx in each phone is the alternative.
>
> And has already been started by nextel, and perhaps others.

I'm led to understand that there isn't a phone Verizon sells anymore that
*doesn't* have GPS. I know my five-month-old Verizon Kyocera 2325 has it,
though my somewhat older 3035e doesn't.

--
JustThe.net Internet & New Media Services
22674 Motnocab Road * Apple Valley, CA 92307-1950
Steve Sobol, Proprietor
888.480.4NET (4638) * 248.724.4NET * [email protected]

In alt.cellular John P Vassel <[email protected]> wrote:
> David Lesher <[email protected]> wrote in
> news:[email protected]:
>
>> More exact schemes use in effect ping timing; you are 3 ms from Cell
>> 34D, 4 ms from Cell 56Q, and 6 ms from Cell 66R; where are you?
>> But it appears this scheme is not fulfilling the FCC specs. Installing
>> a GPS rx in each phone is the alternative.
>
> And has already been started by nextel, and perhaps others.

I'm led to understand that there isn't a phone Verizon sells anymore that
*doesn't* have GPS. I know my five-month-old Verizon Kyocera 2325 has it,
though my somewhat older 3035e doesn't.

--
JustThe.net Internet & New Media Services
22674 Motnocab Road * Apple Valley, CA 92307-1950
Steve Sobol, Proprietor
888.480.4NET (4638) * 248.724.4NET * [email protected]

In article <[email protected]>,
Steven J Sobol <[email protected]> wrote:
>In alt.cellular John P Vassel <[email protected]> wrote:
>> David Lesher <[email protected]> wrote in
>> news:[email protected]:
>>
>>> More exact schemes use in effect ping timing; you are 3 ms from Cell
>>> 34D, 4 ms from Cell 56Q, and 6 ms from Cell 66R; where are you?
>>> But it appears this scheme is not fulfilling the FCC specs. Installing
>>> a GPS rx in each phone is the alternative.
>>
>> And has already been started by nextel, and perhaps others.
>
>I'm led to understand that there isn't a phone Verizon sells anymore that
>*doesn't* have GPS. I know my five-month-old Verizon Kyocera 2325 has it,
>though my somewhat older 3035e doesn't.

The GPS scheme uses a technique where most of the work of the GPS protocol
is done in the cell site, with the result that the location process works
in many situations where standalone GPS units will not work, such as indoors
and in city streets between tall buildings. While most current Verizon phones
have the required hardware, it seems that the corresponding equipment in
cell sites is not in a lot of places. And then, the connections to the
PSAPs (911 centers) has to be done to pass the information on to them.
We will know when the cell sites are updated
when we hear about location-specific applications such as SMS ads telling
you about the great deal on Big Macs at the nearby McDonalds :-(.

www.snaptrack.com has an overview of the "Assisted GPS" product.

In article <[email protected]>,
Steven J Sobol <[email protected]> wrote:
>In alt.cellular John P Vassel <[email protected]> wrote:
>> David Lesher <[email protected]> wrote in
>> news:[email protected]:
>>
>>> More exact schemes use in effect ping timing; you are 3 ms from Cell
>>> 34D, 4 ms from Cell 56Q, and 6 ms from Cell 66R; where are you?
>>> But it appears this scheme is not fulfilling the FCC specs. Installing
>>> a GPS rx in each phone is the alternative.
>>
>> And has already been started by nextel, and perhaps others.
>
>I'm led to understand that there isn't a phone Verizon sells anymore that
>*doesn't* have GPS. I know my five-month-old Verizon Kyocera 2325 has it,
>though my somewhat older 3035e doesn't.

The GPS scheme uses a technique where most of the work of the GPS protocol
is done in the cell site, with the result that the location process works
in many situations where standalone GPS units will not work, such as indoors
and in city streets between tall buildings. While most current Verizon phones
have the required hardware, it seems that the corresponding equipment in
cell sites is not in a lot of places. And then, the connections to the
PSAPs (911 centers) has to be done to pass the information on to them.
We will know when the cell sites are updated
when we hear about location-specific applications such as SMS ads telling
you about the great deal on Big Macs at the nearby McDonalds :-(.

www.snaptrack.com has an overview of the "Assisted GPS" product.

You may be just a little behind the curve. A suspected double murderer just
north of Atlanta, GA fled from police on foot while at the same time talking
on his cell phone. They searched his home and found the cell phone records.
Once they knew his phone, they put a trace on it, but by this time he was near
Chicago and still headed north. They surrounded him in a hospital parking lot
in Wisconsin, after putting down nail strips to take the tires out, with the
cell phone still on sending a signal to every tower he passed.

Tom J
Seemed to work better than OnStar to me

"CharlesH" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>,
> Steven J Sobol <[email protected]> wrote:
> >In alt.cellular John P Vassel <[email protected]> wrote:
> >> David Lesher <[email protected]> wrote in
> >> news:[email protected]:
> >>
> >>> More exact schemes use in effect ping timing; you are 3 ms from Cell
> >>> 34D, 4 ms from Cell 56Q, and 6 ms from Cell 66R; where are you?
> >>> But it appears this scheme is not fulfilling the FCC specs. Installing
> >>> a GPS rx in each phone is the alternative.
> >>
> >> And has already been started by nextel, and perhaps others.
> >
> >I'm led to understand that there isn't a phone Verizon sells anymore that
> >*doesn't* have GPS. I know my five-month-old Verizon Kyocera 2325 has it,
> >though my somewhat older 3035e doesn't.
>
> The GPS scheme uses a technique where most of the work of the GPS protocol
> is done in the cell site, with the result that the location process works
> in many situations where standalone GPS units will not work, such as indoors
> and in city streets between tall buildings. While most current Verizon
phones
> have the required hardware, it seems that the corresponding equipment in
> cell sites is not in a lot of places. And then, the connections to the
> PSAPs (911 centers) has to be done to pass the information on to them.
> We will know when the cell sites are updated
> when we hear about location-specific applications such as SMS ads telling
> you about the great deal on Big Macs at the nearby McDonalds :-(.
>
> www.snaptrack.com has an overview of the "Assisted GPS" product.
>

You may be just a little behind the curve. A suspected double murderer just
north of Atlanta, GA fled from police on foot while at the same time talking
on his cell phone. They searched his home and found the cell phone records.
Once they knew his phone, they put a trace on it, but by this time he was near
Chicago and still headed north. They surrounded him in a hospital parking lot
in Wisconsin, after putting down nail strips to take the tires out, with the
cell phone still on sending a signal to every tower he passed.

Tom J
Seemed to work better than OnStar to me

"CharlesH" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>,
> Steven J Sobol <[email protected]> wrote:
> >In alt.cellular John P Vassel <[email protected]> wrote:
> >> David Lesher <[email protected]> wrote in
> >> news:[email protected]:
> >>
> >>> More exact schemes use in effect ping timing; you are 3 ms from Cell
> >>> 34D, 4 ms from Cell 56Q, and 6 ms from Cell 66R; where are you?
> >>> But it appears this scheme is not fulfilling the FCC specs. Installing
> >>> a GPS rx in each phone is the alternative.
> >>
> >> And has already been started by nextel, and perhaps others.
> >
> >I'm led to understand that there isn't a phone Verizon sells anymore that
> >*doesn't* have GPS. I know my five-month-old Verizon Kyocera 2325 has it,
> >though my somewhat older 3035e doesn't.
>
> The GPS scheme uses a technique where most of the work of the GPS protocol
> is done in the cell site, with the result that the location process works
> in many situations where standalone GPS units will not work, such as indoors
> and in city streets between tall buildings. While most current Verizon
phones
> have the required hardware, it seems that the corresponding equipment in
> cell sites is not in a lot of places. And then, the connections to the
> PSAPs (911 centers) has to be done to pass the information on to them.
> We will know when the cell sites are updated
> when we hear about location-specific applications such as SMS ads telling
> you about the great deal on Big Macs at the nearby McDonalds :-(.
>
> www.snaptrack.com has an overview of the "Assisted GPS" product.
>

"Tom J" <[email protected]> wrote in
news:[email protected]:

> You may be just a little behind the curve.

At least two of the nextel phones have true GPS recievers built into
them. They will send their location via nextel after a few seconds of
connection. It's intent is to be used in conjunction with local info
services. In the event the phone doesnt have a satelite lock, the tower
it's talking to will be used. Kinda neat, now if someone would build a
java app to use this reciever for geocaching info I'd have one less
device on my hands...

john

"Tom J" <[email protected]> wrote in
news:[email protected]:

> You may be just a little behind the curve.

At least two of the nextel phones have true GPS recievers built into
them. They will send their location via nextel after a few seconds of
connection. It's intent is to be used in conjunction with local info
services. In the event the phone doesnt have a satelite lock, the tower
it's talking to will be used. Kinda neat, now if someone would build a
java app to use this reciever for geocaching info I'd have one less
device on my hands...

john