The Mystery of Cell Towers

[Richmond]

In the manual for Network Cell Info (NCI) it says:

"NOTE! We do not show tower locations, but indications of cell locations
from Mozilla MLS database. We do not have tower database."

What is a cell which is not a tower? Maybe the type which is on a
lampost? Why does NCI need the Mozilla database?

It seems to me if you know where someone is, and that someone is moving,
and that someone is in range of more than one cell then you ought to be
able to work out where the signal is coming from.

In the Mozilla link below it says they get info from NCI.

I have two apps installed, Open Signal, and NCI, and they don't seem to
agree with each other about where cell towers are, or even agree with
themselves, as cell towers sometimes vanish.

https://www.m2catalyst.com/manual

https://wiki.mozilla.org/CloudServices/Location/Software#Android

[Abandoned Trolley]

Whats the mystery ?

In urban areas, "Antenna Support Structures" are rarely going to be towers.

[Richmond]

The map (NCI) shows them as towers. But the main mystery is where they
are.

[Abandoned Trolley]

>>
>> Whats the mystery ?
>>
>> In urban areas, "Antenna Support Structures" are rarely going to be towers.
>
> The map (NCI) shows them as towers. But the main mystery is where they
> are.

So ... it shows the locations, but you are unable to identify them ?

Whats the actual problem ?

[Richmond]

As I said, the two apps don't agree, and cell 'towers' or 'cells' vanish
from the map, or move.

[Abandoned Trolley]

Theres a number of reasons for them apparently disappearing, especially
if you are driving around in the area.

If the sites are sectorised theres no need for them to be symmetrical

[Richmond]

I am not driving. One cell in particular vanishes when I walk towards
it. If I am walking towards it then I ought to be staying in the
sector. I have my doubts about whether it exists as it appears to be in
someone's garden.

[Woody]

Could it be because m2catalyst are an American company?
Could it also be that the UK SPs stopped providing cell site info some
years ago (IMSMC initiated by EE) as it cost too much to keep the
(publicly visible) database up to date.
Could it also be that if you tell the dumb idiots of this country who
believe that (for example) because 5G (and I would expect 4G as well)
use GPS the masts are being used to track people - so the idiots go and
set fire to them?

I'm sure I could think of a few more reasons?

[Woody]

Q1: how do you know the cell mast/tower is (a) used by your SP and/or
(b) your phone is registered on that site?

Q2: cell sites are pretty well never built in people's gardens - in
fields, on local authority property, on the top large buildings yes -
but NEVER in Joe Public's back garden.

When you are close to site - even if it is sectored - because of signal
strength you could be attached to any sector on that mast. When you go
away from it you will find out simply by whether your phone continues to
work or not. What is more the antennae on most masts have built-in
down-tilt, that is if the antenna is upright the signal may be being
projected with a downwards tilt of 5, 10 or even 15 degrees to stop the
signal getting too far. Sometimes you might even see an antenna tilted
backwards to throw the signal further than normal if required.

Radio transmission can be magic and/or a black art even to those of us
who have spent a lifetime working in the industry!

[Richmond]

Woody <harro...@ntlworld.com> writes:

> On Tue 06/02/2024 15:57, Richmond wrote:
>> In the manual for Network Cell Info (NCI) it says: "NOTE! We do not
>> show tower locations, but indications of cell locations from Mozilla
>> MLS database. We do not have tower database." What is a cell which
>> is not a tower? Maybe the type which is on a lampost? Why does NCI
>> need the Mozilla database? It seems to me if you know where someone
>> is, and that someone is moving, and that someone is in range of more
>> than one cell then you ought to be able to work out where the signal
>> is coming from. In the Mozilla link below it says they get info from
>> NCI. I have two apps installed, Open Signal, and NCI, and they don't
>> seem to agree with each other about where cell towers are, or even
>> agree with themselves, as cell towers sometimes vanish.
>> https://www.m2catalyst.com/manual
>> https://wiki.mozilla.org/CloudServices/Location/Software#Android
>
>
> Could it be because m2catalyst are an American company?

Maybe. But I am not sure that would exclude them from providing a map of
cells. The app shows a map with cells on it in the UK.

'Three' is owned by a company based in Hong Kong.

> Could it also be that the UK SPs stopped providing cell site info some
> years ago (IMSMC initiated by EE) as it cost too much to keep the
> (publicly visible) database up to date.

Maybe, but the app says it gets data from Mozilla. Where does Mozilla
get it? Open Signal claims to get data from people using the app. So I
thought it was possible to derive information from the signals received
by the phone. Perhaps it is not.

> Could it also be that if you tell the dumb idiots of this country who
> believe that (for example) because 5G (and I would expect 4G as well)
> use GPS the masts are being used to track people - so the idiots go
> and set fire to them?

We don't have anyone like that around here. This is a respectable
neighbourhood.

>
> I'm sure I could think of a few more reasons?

Well you put a question mark at the end, so maybe you aren't sure? ;)

[Richmond]

Woody <harro...@ntlworld.com> writes:

> On Tue 06/02/2024 17:42, Richmond wrote:
>> Abandoned Trolley <fr...@fred-smith.co.uk> writes:
>>
>>> On 06/02/2024 16:36, Richmond wrote:
>>>> Abandoned Trolley <fr...@fred-smith.co.uk> writes:
>>>>
>>>>>>>
>>>>>>> Whats the mystery ?
>>>>>>>
>>>>>>> In urban areas, "Antenna Support Structures" are rarely going to
>>>>>> be towers. The map (NCI) shows them as towers. But the main
>>>>>> mystery is where they are.
>>>>>
>>>>>
>>>>> So ... it shows the locations, but you are unable to identify them
>>>>> ?
>>>>>
>>>>> Whats the actual problem ? As I said, the two apps don't agree,
>>>> and cell 'towers' or 'cells' vanish from the map, or move.
>>>
>>> Theres a number of reasons for them apparently disappearing,
>>> especially if you are driving around in the area.
>>>
>>> If the sites are sectorised theres no need for them to be
>> symmetrical I am not driving. One cell in particular vanishes when I
>> walk towards it. If I am walking towards it then I ought to be
>> staying in the sector. I have my doubts about whether it exists as it
>> appears to be in someone's garden.
>>
> Q1: how do you know the cell mast/tower is (a) used by your SP and/or
> (b) your phone is registered on that site?

The app (NCI) shows a line going from me to the cell. I suppose that is
what it is meant to indicate. If I switch between 2G, 3G, 4G it shows
connections to different cells. If I walk from the front of the house to
the back it switches between a cell to the south and a cell to the
north.

>
> Q2: cell sites are pretty well never built in people's gardens - in
> fields, on local authority property, on the top large buildings yes -
> but NEVER in Joe Public's back garden.

Yes, so why is it showing a cell there? If it was an error in the data
it wouldn't vanish, so I suspect it was working something out based on
the signals it was getting.

>
> When you are close to site - even if it is sectored - because of
> signal strength you could be attached to any sector on that mast. When
> you go away from it you will find out simply by whether your phone
> continues to work or not. What is more the antennae on most masts have
> built-in down-tilt, that is if the antenna is upright the signal may
> be being projected with a downwards tilt of 5, 10 or even 15 degrees
> to stop the signal getting too far. Sometimes you might even see an
> antenna tilted backwards to throw the signal further than normal if
> required.
>
> Radio transmission can be magic and/or a black art even to those of us
> who have spent a lifetime working in the industry!

What information can the phone get from the cell? can it get distance
and direction? The phone knows where I am. If it knows the distance to a
cell it ought to be able to draw a circle and say the cell is somewhere
on it. If I move to a different place it can draw another circle, and
then it could deduce that the cell is at one of two points where the
circles intersect. (Unless I walk directly toward or away, in which case
the circles won't intersect).

[Abandoned Trolley]

zilla.org/CloudServices/Location/Software#Android
>
>
> Could it be because m2catalyst are an American company?
> Could it also be that the UK SPs stopped providing cell site info some
> years ago (IMSMC initiated by EE) as it cost too much to keep the
> (publicly visible) database up to date.
> Could it also be that if you tell the dumb idiots of this country who
> believe that (for example) because 5G (and I would expect 4G as well)
> use GPS the masts are being used to track people - so the idiots go and
> set fire to them?
>
> I'm sure I could think of a few more reasons?
>

Do you think that any of these applications are able to interrogate the
neighbour list on the phone ?

[Woody]

Your phone simply logs on to a control channel for the best signal it
can find. As you move around the phone starts doing a background scan
for other control channels when the signal gets below a certain level
and under certain circumstances may also look at the bit error rate on
control channels.
When in traffic if the signal gets down to a certain level it will send
a data message to the system control on the traffic channel and time
slot allocated to you requesting a change to a new site that it has
found. If the system has resources available on the new site it will
send a change command to your mobile through the traffic channel and at
the same time reroute the call to the new allocation. If it has no
resources available it will reject the request under which circumstances
your phone may ask for another channel that it has found and the
sequence repeats. Ultimately if no resources are available on any site
that you can receive it will leave you where you are until resources are
available or your call drops out.
There are facilities under high system loads for a given site to request
additional resources at which point the system control can move a
channel or channels to your serving site from another nearby site and
then replace that channel with something from somewhere else. These
change sequences are so quick that you may well be unaware that it is
happening other than a change in audio quality or volume occasionally.
GSM has 8 times slots per channel. The control channel is one time slot
on one channel on the site leaving seven calls available on the same
channel. If there is still demand and a second channel is opened up that
gives another eight time slots, i.e. there is only one control channel
on a site no matter how many traffic slots are in use.
4G and 5G handle calls in a different way albeit the basic theory is
very similar.

[JMB99]

On 06/02/2024 15:57, Richmond wrote:
> What is a cell which is not a tower? Maybe the type which is on a
> lampost? Why does NCI need the Mozilla database?

One of the many in places like shopping malls?

[Woody]

I've never yet seen one on a lamppost....

[Tweed]

https://advanced-television.com/2023/06/09/ee-deploys-more-small-cells-to-increase-4g-capacity/

There’s one just like this near my work.

[Woody]

Problem is they look very much like town-coverage wi-fi access points
which local authorities are sticking up everywhere. Round here they are
on alternate lampposts which would would suggest a bit over overkill
even for 5G let alone 4G!

[Pamela]

Based on a discussion in this group, smartphone apps are not able to
reliably determine which tower the phone is connected to.

"App to show connected cell tower" (19 Nov 2021) See Message-ID:
<XnsADE721E...@144.76.35.252>

Also .. like you I found Network Cell Info's and OpenSignal's apps did
not always agree. ISTR the biggest discrepancy was related to masts
filling in a small area.

[Richmond]

Thanks. It looks like an intractable problem.

I found this site:

https://opencellid.org/

But when I put in the details of my current serving cell from NCI it
showed me a location about 150 miles away!

[Woody]

And the NCI app would be.....?

[Richmond]

Network Cell Info (Lite)

[David Woolley]

On 06/02/2024 18:34, Woody wrote:
> because 5G (and I would expect 4G as well) use GPS the masts are being
> used to track people

They are regularly used, after the fact, to track people suspected of
crimes, down to the cell level, and I believe even 2G used round trip
time of flight information, which can be used to get higher resolution
information, although I'm not sure if that is routinely logged. At one
time you could register phones with services that used that time of
flight information for medium resolution tracking.

There is, of course, a lot of misinformation about GPS. Even TV
forensics programmes claim the the satellites are tracking you, when, in
fact, the radio transmission is one way: sky to ground.

[Abandoned Trolley]

On 08/02/2024 16:48, David Woolley wrote:
> On 06/02/2024 18:34, Woody wrote:
>> because 5G (and I would expect 4G as well) use GPS the masts are being
>> used to track people
>
> They are regularly used, after the fact, to track people suspected of
> crimes, down to the cell level, and I believe even 2G used round trip
> time of flight information, which can be used to get higher resolution
> information, although I'm not sure if that is routinely logged.  At one
> time you could register phones with services that used that time of
> flight information for medium resolution tracking.
>

2g used "round trip time" in order to send the correct timing advance
signal to the handset.

Obviously it would then know how far the MS was from the BTS, if it was
interested, but not in which direction

[David Woolley]

On 08/02/2024 17:46, Abandoned Trolley wrote:
> 2g used "round trip time" in order to send the correct timing advance
> signal to the handset.
>
> Obviously it would then know how far the MS was from the BTS, if it was
> interested, but not in which direction

If you have sectored antennas, you also have direction, which I think
may be as far as the public services went, but I believe that the system
could be made to measure distance from multiple towers, which allows a
2D solution.

[David Woolley]

On 08/02/2024 20:19, David Woolley wrote:
> the system could be made to measure distance from multiple towers, which
> allows a 2D solution

E.g.
<https://www.iiiweb.net/forensic-services/cell-phone-tower-triangulation/>
and
<https://wrongfulconvictionsblog.org/2012/06/01/cell-tower-triangulation-how-it-works/>.

[Abandoned Trolley]

On 08/02/2024 16:48, David Woolley wrote:

> On 06/02/2024 18:34, Woody wrote:
>> because 5G (and I would expect 4G as well) use GPS the masts are being
>> used to track people
>
> They are regularly used, after the fact, to track people suspected of
> crimes, down to the cell level, and I believe even 2G used round trip
> time of flight information, which can be used to get higher resolution
> information, although I'm not sure if that is routinely logged.  At one
> time you could register phones with services that used that time of
> flight information for medium resolution tracking.
>

2g uses "round trip time" in order to send the correct timing advance

[Abandoned Trolley]

On 08/02/2024 20:19, David Woolley wrote:

If the site is sectored then you would normally know which 120 degree
sector the MS is attached to, which might not provide the accuracy which
you "need"

If its an omni site then you have no chance

Some low capacity BTS sites which appear to be sectored are in fact
quasi-omni

[Abandoned Trolley]

On 08/02/2024 20:25, David Woolley wrote:
> On 08/02/2024 20:19, David Woolley wrote:
>> the system could be made to measure distance from multiple towers,
>> which allows a 2D solution
>
>

> <https://wrongfulconvictionsblog.org/2012/06/01/cell-tower-triangulation-how-it-works/>.



"The post makes the point that data from a single cell tower is
essentially worthless in trying to place someone in a particular
location. The best you can expect is a band within a 120° “pie wedge”
from the cell tower."

[Richmond]

But if the objective is not to know where the person is, but to know
where the cell (tower) is, then the person can move and make another
observation creating a triangle.

[Pamela]

The last time I visited m2catalyst.com, I vaguely recall it said they
were no longer developing the Network Cell Info app (although I could be
mistaken).

[notya...@gmail.com]

This was how Voda did it originally in 1G and that and an inability to work with voice activated transmit in the mobile led to frequent dropped connections compared to BTCellnet (omni directional bases and call not dropped if handset doesn't transmit for a second or two.

[JMB99]

On 08/02/2024 16:48, David Woolley wrote:

> There is, of course, a lot of misinformation about GPS.  Even TV
> forensics programmes claim the the satellites are tracking you, when, in
> fact, the radio transmission is one way: sky to ground.

I completely lost any faith in anything Stephen Fry says when he
explained on a radio or TV programme that GPS worked by the satellite
receiving a signal from your phone or other GPS unit. He obviously had
not idea what he was talking about but spoke as if he did.

[Richmond]

If a phone uses GPS to determine its own whereabouts, and then sends
that information to Google or Apple, then, indirectly, the satellite has
been used for tracking. Although WiFi hot spots could be used in the same
way instead of satellites.