Jeff Liebermann writes:

services and vendors are on the tower, building, pole, whatever. A
tower ID to lat-long database will certainly be useful, but the real
problem is what frequency to use. For example, for LTE:
https://en.wikipedia.org/wiki/List_of_LTE_networks
the bands in use world wide are many and varied. Same with TDM vs
FDM, full duplex vs half duplex, odd splits. Then, there are
sub-bands for each vendor. Notice the number of question marks in
above tables.

You could use GPS coordinates or just scan all the frequencies:
https://en.wikipedia.org/wiki/LTE_frequency_bands

LTE is a pain, we're just moving from a global 3G/UMTS product to LTE.
This means a different antenna design, LTE module version and whatever
for each region and even operator specific ones :-(

--
mikko

In message Stijn De Jong wrote:
On Sat, 18 Feb 2017 01:25:52 -0000 (UTC), Lewis wrote:

The one that provides LTE coverage. As far as I know, they only have one
of those.

I have two completely different types of CellSpot devices, both of which
say LTE.

Here is a photo of one type in my house, called "CellSpot" and "LTE":
http://i.cubeupload.com/uNXXgZ.jpg

that's the only LTE CellSpot I've seen. It has blinkenlights.

Here is a photo of another type alongside it, also called "CellSpot" and
"LTE":
https://u.cubeupload.com/WoN2gQ.jpg

Those are 4G LTE signal boosters which I've never seen before. They were
not on offer from T-Mobile when I asked about a CellSpot for my home.


In the basement (cellspot is in the garage) I have -78dB currently. If I
go into the garage it's about -60dB-65dB, IIRC.

That's absolutely astoundingly high cellular signal strength (RSSI).
All the articles put the range at -50 to -110 or -120dBm.

-50 is the maximum possible, and below -120 there is no signal.

Are you getting that from your T-Mobile micro tower?
How do you know? (Because that's the entire reason for this thread.)

my iPhone displays the dB in the upper left corner. I's at -78 again.

--
I mistook thee for thy better Hamlet Act III scene 4

In message Carlos E. R. wrote:
On 2017-02-18 02:37, Lewis wrote:
In message Carlos E. R. wrote:
On 2017-02-16 21:57, Stijn De Jong wrote:
The one potentially nice thing that OpenSignal provided on Android was a
compass-like pointer toward the tower it's connected to; however, that
pointer doesn't seem even remotely aligned with where I know that tower to
be, so, I'm not sure if that compass-like pointer is fluff or if there is a
major reflection of radio waves going on off of someone's solar panel array
or expansive windows overlooking the valley below.

There is no way the phone can determine the location of the tower from
the signal,

Sure they can. The signal include Latitude and Longitude for the tower.

That's not the signal.

That's decoding the data on it, and reading it. Then finding via GPS the
exact location of the terminal, then calculating the direction of the tower.

No no, orange juice isn't from oranges! First you have to peel the
orange, and then you have to squeeze it. It's not part of the orange!

Whatever.

--
I'll have what the gentleman on the floor is having.

On Fri, 17 Feb 2017 17:21:15 -0500, nospam wrote:

they also refarmed their network so that aws is not required anymore.

Smoking some good stuff, eh? Clue: Amazon Web Services was never required.

Cheers, -- tlvp
--
Avant de repondre, jeter la poubelle, SVP.

In article , tlvp
wrote:


they also refarmed their network so that aws is not required anymore.

Smoking some good stuff, eh? Clue: Amazon Web Services was never required.

clue: don't comment about things you don't understand.

clue#2: don't smoke whatever it is you're smoking.

On Sat, 18 Feb 2017 01:23:56 +0000 (UTC), Stijn De Jong wrote:

Since none of us are gonna run our own tests with three phones in our hands
for weeks on end,

Right. No three phones, just two. And no tests "for weeks on end," just
casual observations. T-Mo vs. VZW:

* Most places in NE I check signal, they're both present and adequate.
* Some places I find T-Mo service utterly absent, but VZW strong enough to
* use (in some of those, at&t is accessible, but won't allow T-Mo roaming).
* Some places I was hoping to find VZW, that one's absent, but T-Mo is OK.
* Still other places neither is usably present.

Others' experiences are almost sure to differ. Cheers, -- tlvp
--
Avant de repondre, jeter la poubelle, SVP.

On 02/17/2017 04:01 PM, Jeff Liebermann wrote:
On Fri, 17 Feb 2017 14:27:15 -0800, The Real Bev
wrote:

On 02/16/2017 07:21 PM, Jeff Liebermann wrote:
Marketing research: How much would pay for such a device?

Nothing. I've been hooked on 'free' for a long time, especially since
the paid version is rarely significantly better than the free version.

Oh well. It's rather difficult to build a company based on a free
product (unless one sells advertising).

Fine with me. Just how much can a person make from app-advertising?

Once the DF method is
established by me or someone else, I'm sure it will be cloned, copied,
or distributed as "open hardware". That's why I haven't done anything
with the idea for several decades. Enjoy free while it lasts. I'm
thinking more of a Kickstarter, Indiegogo, or other crowdfunding
project.

And yet people do it...

--
Cheers, Bev
"My dad used to say: Laugh, and the whole world laughs with you.
Cry, and I'll give you something to cry about you little
*******." -Jeff Goldblum

In article , The Real Bev
wrote:

Marketing research: How much would pay for such a device?

Nothing. I've been hooked on 'free' for a long time, especially since
the paid version is rarely significantly better than the free version.

Oh well. It's rather difficult to build a company based on a free
product (unless one sells advertising).

Fine with me. Just how much can a person make from app-advertising?

a lot.

http://www.adweek.com/digital/google...billion-even-m
obile-continues-pose-challenges-172722/
During the second quarter of 2016, Alphabet's revenue hit $21.5
billion, a 21 percent year-over-year increase. Of that revenue, $19.1
billion came from Google's advertising business, up from $16 billion
a year ago.

On Fri, 17 Feb 2017 17:12:20 -0800, Jeff Liebermann wrote:

As for the tower antenna patterns being direction, it's a matter of
what you consider directional. In the typical 3 sided tower
configuration, the sector antennas have a horizontal beamwidth of
about 60 degrees. The tower can and does indicate which sector is
being used, but that has a granularity of 120 degrees, which is hardly
accurate enough to determine anyones position.

Hi Jeff,

This article describes the three 120-degree sectors:
Alpha is the North FACING vertical antenna on the cell tower
Beta is the Southeast FACING vertical antenna on the cell tower
Gamma is the Southwest FACING vertical antenna on the cell tower
http://www.evdoforums.com/thread15374.html

There is a way to tell which sector antenna you're connected to from the
cell id. Also, the newer Android APIs now seem to expose the frequency
bands:
http://people.csail.mit.edu/bkph/cel...r_inside.shtml

On Sat, 18 Feb 2017 14:20:39 -0000 (UTC), Lewis wrote:

Here is a photo of one type in my house, called "CellSpot" and "LTE":
http://i.cubeupload.com/uNXXgZ.jpg

that's the only LTE CellSpot I've seen. It has blinkenlights.

Thanks for confirming which one, because there is an entire thread on the
various very different "things" that T-Mobile MARKETING calls a "Personal
CellSpot" which they also call a "4G LTE CellSpot" such that saying those
words is rendered meaningless.

If someone says they have a CellSpot, or a "Personal CellSpot", all they're
definitively saying is that they have a micro tower, but there are multiple
types of similarly branded micro towers, each of which is quite different
in operation.

1. One type is a signal booster, which is purely cellular.
2. Another type is a microtower connected to your Internet router.
3. A third type is a router (I have not tested this type yet).
4. A fourth type is an access point (I haven't tested this either, yet).
5. And, while we're at it, there is WiFi calling (which isn't a "cellspot")

Here is a photo of another type alongside it, also called "CellSpot" and
"LTE":
https://u.cubeupload.com/WoN2gQ.jpg

Those are 4G LTE signal boosters which I've never seen before. They were
not on offer from T-Mobile when I asked about a CellSpot for my home.

Yes, but my point is that they also are branded by T-Mobile MARKETING as a
"Personal CellSpot" and they all say "4G LTE".

The only difference in branding is in the final word *after* the
meaningless "CellSpot" brand name (and in the case of the one you have,
they don't even put a final word after the meaningless "CellSpot" brand
name).


In the basement (cellspot is in the garage) I have -78dB currently. If I
go into the garage it's about -60dB-65dB, IIRC.

That's absolutely astoundingly high cellular signal strength (RSSI).
All the articles put the range at -50 to -110 or -120dBm.

-50 is the maximum possible, and below -120 there is no signal.

Are you getting that from your T-Mobile micro tower?
How do you know? (Because that's the entire reason for this thread.)

my iPhone displays the dB in the upper left corner. I's at -78 again.

I knew how you got the decibel RSSI (received signal strength indication),
but the question was how do you know which "tower" you're getting your
current signal from.

As far as anyone can tell, it's impossible to get the cell id tower from
the phone on an iOS device, so you have to use an Android device to figure
that out.

I have a similar setup to yours, except that I have at least three (and
maybe more) towers for my phone to choose from (two of which are inside my
own home).

So just having a decibel reading doesn't tell me *which* tower I'm
connected to (since there are at least three or more to choose from).

The good news is that my decibel readings are now in the -50dBm to -60dBm
range (instead of the minus 90 to minus 100 decibel range as they were
before I hooked up the micro towers!).

In article , Stijn De Jong
wrote:

In the basement (cellspot is in the garage) I have -78dB currently. If I
go into the garage it's about -60dB-65dB, IIRC.

That's absolutely astoundingly high cellular signal strength (RSSI).
All the articles put the range at -50 to -110 or -120dBm.

-50 is the maximum possible, and below -120 there is no signal.

Are you getting that from your T-Mobile micro tower?
How do you know? (Because that's the entire reason for this thread.)

my iPhone displays the dB in the upper left corner. I's at -78 again.

I knew how you got the decibel RSSI (received signal strength indication),
but the question was how do you know which "tower" you're getting your
current signal from.

based on what you've written, no, you did not know that.

As far as anyone can tell, it's impossible to get the cell id tower from
the phone on an iOS device,

wrong.

so you have to use an Android device to figure
that out.

maybe you do, but the rest of the world doesn't, assuming they even
care what the tower id is.

everyone *other* than cellular engineers don't care, and the cellular
engineers have *far* more sophisticated equipment to find out than by
using an android or ios phone.

On Fri, 17 Feb 2017 18:43:40 -0800, Jeff Liebermann wrote:

My GSM phones show a valid lat-long. My CDMA phones show no data.

Hi Jeff,
I'm still trying to figure this stuff out, but I noticed this MIT app
(CellTracker) "attempts" to show both what the GPS says and the latitude
and longitude for Verizon.
http://people.csail.mit.edu/bkph/ima...04-16-15-29-00

CellTracker:
http://people.csail.mit.edu/bkph/CellTracker

On Sat, 18 Feb 2017 03:23:29 +0100, Carlos E. R. wrote:

There is no way the phone can determine the location of the tower from
the signal,

Sure they can. The signal include Latitude and Longitude for the tower.

That's not the signal.

That's decoding the data on it, and reading it. Then finding via GPS the
exact location of the terminal, then calculating the direction of the tower.

This finding-where-the-tower is stuff is all new to me, but from what I've
been reading, it's impossible to do on an iPhone, and, the directional
pointer on OpenSignal is, at best, a wild-assed guess.

I'm still trying to figure all this out, but, it seems that OpenSignal is
likely a phony app that simply uses your cellular connection to *guess*
which cell tower you're connected to (based purely on your signal strength
and carrier).

The actual location of the tower is well known to be wrong, since it's
merely an average location of the *cell phones*!

Yup. They don't locate the tower.
They simply average the location of the cellphone locations!

Says so he
"In OpenSignal ... the tower locations reported are not the actual
antenna coordinates but the average of coordinates where cell phones were
when they connected to that antenna"
http://people.csail.mit.edu/bkph/cel...r_inside.shtml

Here's a classic result of the OpenSignal inaccurate averaging algorithm:
http://people.csail.mit.edu/bkph/ima...1130072559.png

On Sat, 18 Feb 2017 14:22:35 -0000 (UTC), Lewis wrote:

That's decoding the data on it, and reading it. Then finding via GPS the
exact location of the terminal, then calculating the direction of the tower.

No no, orange juice isn't from oranges! First you have to peel the
orange, and then you have to squeeze it. It's not part of the orange!

Whatever.

I had never used these apps before a couple of days ago, but now, after
using a dozen of these cellular reporting apps, I'd assess OpenSignal to be
almost non-functional compared to the apps that actually report correct
information.

As a "toy" app, OpenSignal is fine; but for correct and accurate
information, OpenSignal appears to be a veritable bust.

Still, it's one of the only related apps that my iOS device can run, so,
even a toy app such as OpenSignal appears to be (compared to, say, Network
Cell Info Lite) is better than nothing I guess.

The great news is that I've gotten my cellular signal up from around
-100dBm to consistently better than -60dBm, which is an astoundingly
astronomical improvement in signal strength!

For example, here is a reading, just now, of -53dBm on my cellphone:
http://i.cubeupload.com/GEYEzS.jpg

From what I've read, cellular signal doesn't get much better than that.

However, there is so much data that each of these apps output that I'm
still going through all the useful information to figure out exactly which
device is doing what (since I have an old micro tower and a new femto tower
in my house).

On Saturday, February 18, 2017 at 9:24:29 AM UTC-5, Lewis wrote:
In message Carlos E. R. wrote:
On 2017-02-18 02:37, Lewis wrote:
In message Carlos E. R. wrote:
On 2017-02-16 21:57, Stijn De Jong wrote:
The one potentially nice thing that OpenSignal provided on Android was a
compass-like pointer toward the tower it's connected to; however, that
pointer doesn't seem even remotely aligned with where I know that tower to
be, so, I'm not sure if that compass-like pointer is fluff or if there is a
major reflection of radio waves going on off of someone's solar panel array
or expansive windows overlooking the valley below.

There is no way the phone can determine the location of the tower from
the signal,

Sure they can. The signal include Latitude and Longitude for the tower.

That's not the signal.

That's decoding the data on it, and reading it. Then finding via GPS the
exact location of the terminal, then calculating the direction of the tower.

No no, orange juice isn't from oranges!

Correct. Its from water, other molecules, elements and sunlight absorbed by the Orange Tree.

On Thu, 16 Feb 2017 01:52:24 +0000 (UTC), Stijn De Jong wrote:

Q: Which app do you use on iOS or Android to figure out all the cellular
towers and signal strengths of the cellular signal (CDMA or GSM) in your
area?

Summary of the freebie app selected after a few days of testing.

I've dumped the freeware version of Network Signal Info because it kept
hanging, and opted to use as my primary real-time app "Network Cell Info
Lite" (The best logging app was NetMonitor).

One nice thing about Network Signal Info payware is that it reports not
only the current (aka registered) cell, but also the neighbor cell
strengths.
http://wilysis.com/networkcellinfo

Here are some screenshots of today's scan to help you see what it reports.

The good news is that I've brought my signal strength in the mountains,
miles from the nearest T-Mobile tower, up from around minus ninety to minus
one hundred decibels to consistently better than minus fifty-five to minus
sixty-five decibels (which is astounding!).

Here are the results of a scan this morning from my new "gsm" folder:
http://i.cubeupload.com/lgDafB.jpg

In this scan are the unique cell tower identification numbers:
http://i.cubeupload.com/5H7qmX.jpg

The second tab shows the ever-changing raw data in text format:
http://i.cubeupload.com/3gMofW.jpg

While the third tab shows a time-sequence graph showing consistency:
http://i.cubeupload.com/3rDsHX.jpg

There are multiple plots of multiple types of signal strengths:
http://i.cubeupload.com/4HQqh8.jpg

And a quick table of DATA ON/OFF connection percentage statistics:
http://i.cubeupload.com/NQ0xJU.jpg

You can export the entire database in multiple file formats:
http://i.cubeupload.com/W1AAaK.jpg

And there is a nice summary page of the device & sim card information:
http://i.cubeupload.com/hCXKXJ.jpg

I may end up getting the payware if I can't find a freeware app that
reports the neighbor cell strengths, which would also be useful
information.

But there are plenty of freeware apps to explore, e.g., this MIT app:
http://people.csail.mit.edu/bkph/CellTracker.shtml

On Thu, 16 Feb 2017 01:52:24 +0000 (UTC), Stijn De Jong wrote:

Q: Which app do you use on iOS or Android to figure out all the cellular
towers and signal strengths of the cellular signal (CDMA or GSM) in your
area?

This is a question and initial observation for Jeff Liebermann.

QUESTION:
Does a cellular booster propagate the original cell tower identification?
(Or does the boosted signal have its own cell tower identification number?)

OBSERVATION:
1. I can range my cellular signal strength by almost half a million times:
http://i.cubeupload.com/zN4Dkb.jpg

2. I ran an experiment, starting with a stead very good signal strength:
http://i.cubeupload.com/TPLLXF.jpg

3. Then I unplugged, one by one, the two micro towers in my house:
http://i.cubeupload.com/ciKH3h.jpg

Interestingly, when I unplugged the router-connected micro tower, I could
see the unique cell tower ID change immediately to a set of cell towers
that are known to be within a few miles of me.

Yet, when I unplugged the cellular booster, the signal dropped, but the
cell towers simply went to a much larger set of cell towers, some of which
are known to be ten or fifteen miles away. However, I could still see the
set of towers in the prior step in the makeup.

My initial assumption (which needs to be tested) is two fold:
a. It seems the router-connected micro tower has its own unique cell id.
b. It seems the booster may simply propagate the "real" cell tower cell id.

Does that make sense?

In message Stijn De Jong wrote:
I knew how you got the decibel RSSI (received signal strength indication),
but the question was how do you know which "tower" you're getting your
current signal from.

I haven never cared to check. If I unplug the t-mbile cellspot, my
signal in the basement drops significantly and I lose calls.

I don't care which tower or micro tower I am connected to.

So just having a decibel reading doesn't tell me *which* tower I'm
connected to (since there are at least three or more to choose from).

So? Who cares?

The good news is that my decibel readings are now in the -50dBm to -60dBm
range (instead of the minus 90 to minus 100 decibel range as they were
before I hooked up the micro towers!).

That's all that matters.

--
The real American folksong is a rag -- a mental jag A rhythmic tone for
the chronic blues

On Sat, 18 Feb 2017 13:09:46 -0800, The Real Bev
wrote:

On 02/17/2017 04:01 PM, Jeff Liebermann wrote:
On Fri, 17 Feb 2017 14:27:15 -0800, The Real Bev
wrote:

Just how much can a person make from app-advertising?

You keep thinking of an Android App. This is a hardware based
direction finder that has a built in computah to do the number
crunching. No smartphone or Android gizmo involved. Therefore, I
won't be selling apps on the Play Store.

"Google Play app revenue up 82% in Q4 2016, 60% growth for the App
Store"
http://www.gsmarena.com/google_play_app_revenue_up_82_in_q4_2016_60_growth _for_the_app_store-news-22759.php
Google Play store collected $3.3Billion in revenue. Last year, the
split was 70% Google and 30% developer. Therefore the developers
collected about:
$3.3 billion / 0.7 * 0.3 = $1.4 billion
This year, the split is 85% Google and 15% developer, which indicates
that Google is getting greedy, developers were making to much money,
or both.

Blundering onward, the Play store has 2.6 million apps available.
About half are free, so that's 1.3 million apps. Average revenue per
app would be:
$1.4 billion revenue / 1.3 million apps = $1,100 revenue/app/year
Not enough to support product development.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sat, 18 Feb 2017 21:14:27 +0000 (UTC), Stijn De Jong
wrote:

On Fri, 17 Feb 2017 17:12:20 -0800, Jeff Liebermann wrote:

As for the tower antenna patterns being direction, it's a matter of
what you consider directional. In the typical 3 sided tower
configuration, the sector antennas have a horizontal beamwidth of
about 60 degrees. The tower can and does indicate which sector is
being used, but that has a granularity of 120 degrees, which is hardly
accurate enough to determine anyones position.

Hi Jeff,

This article describes the three 120-degree sectors:
Alpha is the North FACING vertical antenna on the cell tower
Beta is the Southeast FACING vertical antenna on the cell tower
Gamma is the Southwest FACING vertical antenna on the cell tower
http://www.evdoforums.com/thread15374.html

I dialed #878# and got:
"Welcome to Verizon Wireless. Your call cannot be completed as
dialed..."

There is a way to tell which sector antenna you're connected to from the
cell id. Also, the newer Android APIs now seem to expose the frequency
bands:
http://people.csail.mit.edu/bkph/cel...r_inside.shtml

Nice article. I think there is a way of extracting the sector but I
don't know what it might be and am too lazy to work it out right now.
My leaky roof and irate customers come first.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

In article , Jeff
Liebermann wrote:

Blundering onward, the Play store has 2.6 million apps available.
About half are free, so that's 1.3 million apps. Average revenue per
app would be:
$1.4 billion revenue / 1.3 million apps = $1,100 revenue/app/year
Not enough to support product development.

the average isn't what matters. a quality app can be *very* profitable.

On Sat, 18 Feb 2017 21:31:53 +0000 (UTC), Stijn De Jong
wrote:

On Fri, 17 Feb 2017 18:43:40 -0800, Jeff Liebermann wrote:

My GSM phones show a valid lat-long. My CDMA phones show no data.

I'm still trying to figure this stuff out, but I noticed this MIT app
(CellTracker) "attempts" to show both what the GPS says and the latitude
and longitude for Verizon.
http://people.csail.mit.edu/bkph/ima...04-16-15-29-00

CellTracker:
http://people.csail.mit.edu/bkph/CellTracker

Nice app, but it does NOT show the lat-long of the local Verizon cell
site. See attached screen grab:
http://802.11junk.com/jeffl/crud/CellTracker.jpg
Celltracker for Android 5.0 on a Moto G v1 phone running Android 5.1.
Note from the screengrab that the GPS is on and running. The "WIFI
Lat-Long" is the location of my house, not the local cell site. I
don't know where my Lat-Long came from (probably Google Maps
database).

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sat, 18 Feb 2017 22:52:40 -0500, nospam wrote:

the average isn't what matters. a quality app can be *very* profitable.

So can a lottery ticket, and it's easier to develop. Cheers, -- tlvp
--
Avant de repondre, jeter la poubelle, SVP.

On Sun, 19 Feb 2017 02:07:16 +0000 (UTC), Stijn De Jong
wrote:

On Thu, 16 Feb 2017 01:52:24 +0000 (UTC), Stijn De Jong wrote:

Q: Which app do you use on iOS or Android to figure out all the cellular
towers and signal strengths of the cellular signal (CDMA or GSM) in your
area?

This is a question and initial observation for Jeff Liebermann.

Why me?

Does a cellular booster propagate the original cell tower identification?
(Or does the boosted signal have its own cell tower identification number?)

By "booster" are you referring to a bi-directional amplifier like
products from Wilson:
http://www.wilsonpro.com/residential-cell-phone-signal-boosters
or Wi-Ex (zBoost)?
https://www.signalboosters.com/zboost-signal-boosters
I so, they repeat exactly the original signals both incoming and
outgoing. What you hear is the tower ID. The device does not
generate any new data or belch a new tower ID.

However, if you're referring to a Femtocell or similar internet
connected microcellular device, the answer is yes, they do have their
own unique ID.

My initial assumption (which needs to be tested) is two fold:
a. It seems the router-connected micro tower has its own unique cell id.

Yep.

b. It seems the booster may simply propagate the "real" cell tower cell id.

Yep.

Does that make sense?

Yep.

How far away do you think the strongest (or nearest) T-mobile cell
tower is located from your test location? Any possibility that one of
your neighbors might have a T-mobile microcell box that you're
hearing? I'm suspicious of the rather strong tower signal.

Back of the envelope calculation:
+27dBm Estimated transmit power from the cell site
+10dB My guess of the panel antenna gain
-53dBm Receive signal level from your test.

Path loss = 27 + 10 + 53 = 90dB
Calculating the distance where the path loss would be -90dB at 700MHz:
http://www.proxim.com/products/knowledge-center/calculations/calculations-free-space-loss
is about 0.7 miles or about 4,000 ft. The cell tower would need to be
rather close to your location for that to work. Like I said, I'm
suspicious of what you're measuring.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sat, 18 Feb 2017 16:29:17 -0500, nospam wrote:

As far as anyone can tell, it's impossible to get the cell id tower from
the phone on an iOS device,

wrong.

Certainly, technically competetent iOS users have tried over the years...
http://stackoverflow.com/questions/1...ork-in-ios-5-1
https://blog.hqcodeshop.fi/archives/...Test-mode.html
http://www.ahmadrifky.com/ict-stuff/...-split-seconds
https://discussions.apple.com/thread...art=0&tstart=0

Even iOS app developers have tried...
https://forums.developer.apple.com/thread/21018
https://sourceforge.net/p/dpfdelphiios/tickets/232/

What do you know that they don't know?

On Sun, 19 Feb 2017 02:31:01 -0000 (UTC), Lewis wrote:

I haven never cared to check. If I unplug the t-mbile cellspot, my
signal in the basement drops significantly and I lose calls.

You are perfectly correct in that simply unplugging a single micro tower
will likely cause the signal strength to "fluctuate".

The signal strength, however, can easily be similar since it fluctuates
normally anyway, e.g., all my neighbors also have micro towers (basically
everyone has them out here).

Worse, when I unplug my booster, it takes about fifteen minutes for the
cell signal to set itself up, and, even then, it seems that the booster
simply "passes through" the cell tower ID it is boosting (I need to
research that further though). So, unplugging it in order to figure out if
I'm connected to it, is problematic.

However far worse than that, when I unplug my router-connected micro tower,
it takes multiple hours for the thing to set itself up. T-Mobile says that
it can take up to two hours, but I found out that it takes even longer than
that, as last night I literally fell asleep before the thing started taking
on my cell phone.

I had to look at the log file in the morning.

BTW, for Jeff Liebermann, I found another app that logs the connections,
so, that's three apps which log all the towers connected to, only one of
which (NetMonitor) allows you to modify how that log appears (which is a
nice feature) to the user in real time.

Some logs save as text, others as CSV, so I'll write up separately for you
and others to benefit, which apps were best for logging the cell tower IDs.

I don't care which tower or micro tower I am connected to.

Most people don't care which tower they're connected to; however, if they
were debugging their connection, they'd start to care.

In my case, T-Mobile only allows one device, which is what I found out when
the second device tried to use the same 911 address as the first device,
so, they "may" ask for one of the devices back (I had asked for a third
device, but that is currently out of the question).

If I have to give one device back, it is helpful to know which device
worked best, and for that, waiting two or more hours between tests is crazy
when I can just look at the unique cell id of the router-based device to
tell if that's what I'm connecting to.

So just having a decibel reading doesn't tell me *which* tower I'm
connected to (since there are at least three or more to choose from).

So? Who cares?

If my good signal strength is actually due to my neighbor's micro tower,
how would I know?

If I have to send back one device to T-Mobile, which device would I send
back?

The good news is that my decibel readings are now in the -50dBm to -60dBm
range (instead of the minus 90 to minus 100 decibel range as they were
before I hooked up the micro towers!).

That's all that matters.

Not really. If T-Mobile wants one of their devices back, which one do I
give them?

In article , Stijn De Jong
wrote:


As far as anyone can tell, it's impossible to get the cell id tower from
the phone on an iOS device,

wrong.

Certainly, technically competetent iOS users have tried over the years...

and have succeeded:

https://ociotec.com/wp-content/uploads/2016/11/proveedor_telefonia.png

https://pbs.twimg.com/media/C29OaIVXAAEPTMG.jpg

In article , tlvp
wrote:


the average isn't what matters. a quality app can be *very* profitable.

So can a lottery ticket, and it's easier to develop. Cheers, -- tlvp

whooosh.

On Sat, 18 Feb 2017 20:14:28 -0800, Jeff Liebermann wrote:

CellTracker:
http://people.csail.mit.edu/bkph/CellTracker

Nice app, but it does NOT show the lat-long of the local Verizon cell
site. See attached screen grab:
http://802.11junk.com/jeffl/crud/CellTracker.jpg

Thanks Jeff for installing that app, which isn't on F-Droid or Google Play,
so we both took a risk in doing so (I'm not sure how to ameliorate that
risk, but that's the topic of a different Android thread).

I've only used that MIT CellTracker for a day, so take everything below
with a grain of salt but look at this screenshot first:
http://i.cubeupload.com/407ihh.jpg

That MIT CellTracker app does appear to list two GPS locations:
1. Where you are
2. Where the connected tower is

That first GPS location it probably gets from our GPS receivers, while the
second GPS (which it calls "NMAP") location is likely from a lookup
database.

Note from the screengrab that the GPS is on and running. The "WIFI
Lat-Long" is the location of my house, not the local cell site. I
don't know where my Lat-Long came from (probably Google Maps
database).

Sometimes it says "NMAP NOT FOUND" as your photo shows, but other times it
says "NMAP" and then the GPS location and height of the tower in meters.

What I don't like about this MIT CellTracker is that it reports signal
strength in ASU and not in Decibels (yes, I know, it can be converted).

However, what I like about this MIT CellTracker non-Google-Play app is I
can see, visually, the documented cell towers bouncing around, even when I
use my signal booster micro tower.

Here's an edited example of what a user might see of that bouncing:
http://i.cubeupload.com/ZHepme.jpg

Celltracker for Android 5.0 on a Moto G v1 phone running Android 5.1.
I'm on Android 4.3 Samsung Galaxy S3, T-Mobile, in the boonies near you.

After two days, I've whittled down the good freeware to 4 applications:
http://i.cubeupload.com/OwXjWZ.jpg

On 2/17/2017 8:36 PM, Savageduck wrote:

I recall driving to Yosemite in the winter one year. It was snowing.
We arrived at the place we were staying and they hadn't left the key
out for us. I called the caretaker who brought over the key.

Was this at Fish Camp, and I guess at some place other than Tenaya Lodge
or the Narrow Gauge Inn?

Yosemite West.

I looked at the maps for all four carriers for that area. Only Verizon
has coverage there. Remember, this area used to be served by a local
carrier, Golden State Cellular, which did a very good job of covering
remote areas. Verizon bought them. T-Mobile has no coverage in Yosemite,
not even in Yosemite Valley, and does not allow roaming. Sprint roams
onto Verizon. AT&T has native coverage in Yosemite Valley. Oddly, the
AT&T map shows two small patches of coverage.

Yosemite West is technically just outside the park boundary but the only
access is from within the park. There are a lot of rental houses and
condominiums in that community so it's a popular area for lodging,
especially in the winter since it's much closer to the downhill ski area
and the majority of XC and snowshoe trails, than Yosemite Valley,
Wawona, or Fish Camp.

Throughout California, once you leave the urban and suburban areas, you
definitely want to have at least an AT&T phone, and preferably a Verizon
phone. Ditto for Oregon. We were up in Bend and out in the area west of
town at Tumalo Falls, and there was only Verizon coverage (probably also
U.S. Cellular coverage). T-Mobile coverage is very spotty. Part of the
problem of course is the PCS frequencies need a lot more towers to cover
the same area as the cellular frequencies. Another advantage of Verizon
is that their using CDMA which is more robust and has greater range.

On Sun, 19 Feb 2017 17:18:40 +0000 (UTC), Stijn De Jong
wrote:

That first GPS location it probably gets from our GPS receivers, while the
second GPS (which it calls "NMAP") location is likely from a lookup
database.

It's MMAP, not NMAP. MMAP (Mobile Message Access Protocol) is a
protocol for sending SMS messages over the internet:
http://www.phonescoop.com/glossary/term.php?gid=269
https://yidonghan.wordpress.com/2008/01/02/mobile-message-access-protocolmmap-version-1-0/
http://xml.coverpages.org/SMS-MMAPv12a.pdf


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 19 Feb 2017 09:41:15 -0800, Jeff Liebermann wrote:

It's MMAP, not NMAP. MMAP (Mobile Message Access Protocol) is a
protocol for sending SMS messages over the internet:
http://www.phonescoop.com/glossary/term.php?gid=269
https://yidonghan.wordpress.com/2008/01/02/mobile-message-access-protocolmmap-version-1-0/
http://xml.coverpages.org/SMS-MMAPv12a.pdf

Oooops. My eyes! They suck! That's the main reason I wish the iOS iPads
could do some of this stuff. I can't *see* the little screen on my S3!

Thanks. I appreciate the correction.

Another thing I appreciate is that you researched the NetMonitor app, which
does logs *better* than all the other apps did!
a. NetMonitor logs are the most customizable
http://i.cubeupload.com/ZAcsok.jpg
b. GSM Signal Monitoring has great csv logs
http://i.cubeupload.com/69bgcS.jpg
b. CellTracker logs manually (by pressing the blue arrows)
http://i.cubeupload.com/FhY2UX.jpg

They all do logs differently though; but what I like about NetMonitor logs
is that you can *change* how the site appears in the real-time log.

So, for example, if a site shows up in NetMonitor originally as:
12345 54321 6789
California, USA, Santa Cruz, CA 95060

You can change that to something that makes sense to you, such as:
12345 54321 6789
1555 Soquel Dr. tower, north facing alpha sector

Or even just the one line:
1555 Soquel Dr. tower, north facing alpha sector

And, in all subsequent logs (real time or post mortem), it will show up
that way for you (or so it seems) with an asterisk in front (it seems).

In summary, all three apps listed above do logs differently, but the app
you suggested for logging does them the best because they're just a bunch
of numbers if you can't change them to indicate something more meaningful
to you (such as the sector or the street location) in real time.

On Sat, 18 Feb 2017 19:48:00 -0800, Jeff Liebermann wrote:

http://www.evdoforums.com/thread15374.html

I dialed #878# and got:
"Welcome to Verizon Wireless. Your call cannot be completed as
dialed..."

I got a similar message, but for T-Mobile (your call cannot be completed as
dialed, or something like that). But I didn't know if it was just T-Mobile
or not.

Thanks for running that test for Verizon.

There is a way to tell which sector antenna you're connected to from the
cell id. Also, the newer Android APIs now seem to expose the frequency
bands:
http://people.csail.mit.edu/bkph/cel...r_inside.shtml

Nice article. I think there is a way of extracting the sector but I
don't know what it might be and am too lazy to work it out right now.
My leaky roof and irate customers come first.

Speaking of leaky roofs, I can't believe the rain we've been having!
I am sick and tired of rain, mudslides, & road closures near the summit!
We're getting a windy storm tomorrow too! (Brace yourself!).

I have completed my initial tests on the Android free apps though.
I know I'm done with the first phase when I've uninstalled all the apps
that irk me.

I'm left with these four, each of which does something nice that the others
don't do as well.
https://i.cubeupload.com/vKLAu8.jpg

While some of these apps do wifi scanning, I keep a separate folder for the
best freeware wifi scanners, as shown below:
https://i.cubeupload.com/Z1qvPZ.jpg

If folks want to save time, you can't go wrong loading just one or more of
those four best freeware apps (in my tests anyway) for cellular debugging.

Network Cell Info Lite, version 3.30:
http://i.cubeupload.com/HoKTav.jpg
http://wilysis.com/networkcellinfo
https://play.google.com/store/apps/d...s.cellinfolite

Netmonitor, version 1.2.15:
https://i.cubeupload.com/TfDJaS.jpg
https://play.google.com/store/apps/d...ene.netmonitor

MIT CellTracker:
http://i.cubeupload.com/ZHepme.jpg
http://people.csail.mit.edu/bkph/CellTracker

GSM Signal Monitoring, version 4.02:
http://i.cubeupload.com/V9O0Gg.jpg
https://play.google.com/store/apps/d...almonitorin g

You'll also want this, but I put it in my WiFi folder instead:
WiGle WiFi Wardriving (which also reports cellular towers):
http://i.cubeupload.com/ZPva3O.jpg
https://play.google.com/store/apps/d...e.wigleandroid

Unfortunately, the freeware version of Network Signal Info crashed a lot
so I uninstalled it, but if it works for you, it's also very good.
Network Signal Info, version 3.63.01:
http://i.cubeupload.com/2zK8Ys.jpg
https://play.google.com/store/apps/d...android.telnet

If you want log files, you are limited to these three, in order:
a. NetMonitor logs are the most customizable
http://i.cubeupload.com/ZAcsok.jpg
b. GSM Signal Monitoring has great csv logs
http://i.cubeupload.com/69bgcS.jpg
b. CellTracker logs manually (by pressing the blue arrows)
http://i.cubeupload.com/FhY2UX.jpg

As always, I hope these detailed summaries and research and tests help
others now, and in the future. Of course, if you have improvements, please
share!

On Sun, 19 Feb 2017 10:43:16 -0500, nospam wrote:

As far as anyone can tell, it's impossible to get the cell id tower from
the phone on an iOS device,

wrong.

Certainly, technically competetent iOS users have tried over the years...

and have succeeded:

https://ociotec.com/wp-content/uploads/2016/11/proveedor_telefonia.png

https://pbs.twimg.com/media/C29OaIVXAAEPTMG.jpg

I've seen those pictures before since they were in the references I already
cited.

Where is the unique cell ID in those pictures?

There is only one "cell id" and it's simply the number 388, which isn't a
unique cell id in any sense of the word.

What do you know that nobody else on iOS knows?

On Sat, 18 Feb 2017 19:48:00 -0800, Jeff Liebermann wrote:

http://www.evdoforums.com/thread15374.html

I dialed #878# and got:
"Welcome to Verizon Wireless. Your call cannot be completed as
dialed..."

Same here, on the other coast, but with the additional text,
"Announcement for switch [digit] [digit] [digit] dash [digit]."

(Actual digits redacted to "[digit]" for privacy's sake.) Cheers, -- tlvp
--
Avant de repondre, jeter la poubelle, SVP.

In article , Stijn De Jong
wrote:

As far as anyone can tell, it's impossible to get the cell id tower from
the phone on an iOS device,

wrong.

Certainly, technically competetent iOS users have tried over the years...

and have succeeded:

https://ociotec.com/wp-content/uploads/2016/11/proveedor_telefonia.png

https://pbs.twimg.com/media/C29OaIVXAAEPTMG.jpg

I've seen those pictures before since they were in the references I already
cited.

yet you still claim it can't be done??

Where is the unique cell ID in those pictures?

There is only one "cell id" and it's simply the number 388, which isn't a
unique cell id in any sense of the word.

nonsense.

What do you know that nobody else on iOS knows?

i don't know about 'nobody else' but it's clear as hell that i know way
the **** more than you do.

On Sat, 18 Feb 2017 23:13:31 -0800, Jeff Liebermann wrote:

This is a question and initial observation for Jeff Liebermann.
Why me?

Good question. I guess it's because I've seen so much made-up stuff from
the likes of nospam, that you're one of the few people here we can trust.

Does a cellular booster propagate the original cell tower identification?
(Or does the boosted signal have its own cell tower identification number?)

By "booster" are you referring to a bi-directional amplifier like
products from Wilson.

T-mobile gives out a signal booster where you put on unit in the window and
another unit in the middle of the house.
https://support.t-mobile.com/docs/DOC-14947

It's supposed to "boost" the signal.
https://support.t-mobile.com/communi...signal-booster

If so, they repeat exactly the original signals both incoming and
outgoing. What you hear is the tower ID. The device does not
generate any new data or belch a new tower ID.

I think this is the case that the signal booster passes through the
original tower ID since I don't see any *new* tower ids when I hook up the
signal booster. Of course, it could just be that the signal booster isn't
working because the signal strength doesn't get any better either.

However, if you're referring to a Femtocell or similar internet
connected microcellular device, the answer is yes, they do have their
own unique ID.

I do have a femtocell also, and that *does* have its own unique ID which I
have identified already.
https://support.t-mobile.com/communi...g-lte-cellspot

So the question was just about whether the booster generates its own unique
cell id or if it just passes through the cell ID of a tower somewhere in
Santa Cruz or San Jose.


My initial assumption (which needs to be tested) is two fold:
a. It seems the router-connected micro tower has its own unique cell id.

Yep.

b. It seems the booster may simply propagate the "real" cell tower cell id.

Yep.

Does that make sense?

Yep.

Thanks. That made sense.
By the way, long ago you helped me set up a Linksys WRT54G as a wired
extender (yes, you cautioned against it in favor of better solutions).

Do you think it makes a difference if I hook up the femtocell to the wired
extender versus the main router?

How far away do you think the strongest (or nearest) T-mobile cell
tower is located from your test location?

The nearest tower is only a couple of miles away, but consistently I get
connected to towers that are ten and fifteen miles away. They bounce around
as I watch them from the MIT CellTracker app.


Any possibility that one of
your neighbors might have a T-mobile microcell box that you're
hearing? I'm suspicious of the rather strong tower signal.

Without the booster and without the femtocell, I get horrid signal, roughly
minus 90 to minus 105 decibels. With the femtocell, I get minus 60 decibels
consistently. I can even have stronger cellular signal strength than wifi
signal strength, which is amazing.

And, yes, *all* my neighbors have either a booster or a femtocell or they
use WiFi calling (since bad signal is ubiquitous in these hills).

Back of the envelope calculation:
+27dBm Estimated transmit power from the cell site
+10dB My guess of the panel antenna gain
-53dBm Receive signal level from your test.

Path loss = 27 + 10 + 53 = 90dB
Calculating the distance where the path loss would be -90dB at 700MHz:
http://www.proxim.com/products/knowledge-center/calculations/calculations-free-space-loss
is about 0.7 miles or about 4,000 ft. The cell tower would need to be
rather close to your location for that to work. Like I said, I'm
suspicious of what you're measuring.

Thanks for showing me how to do the math to approximate the distance to the
antenna based on the received signal strength indication.

I must not have stated clearly which is that the only time I get minus
sixty decibels is when the femtotower is in place, where it's only a few
feet from my phone.

Otherwise, I get around minus a hundred decibels, which sucks.
+27dBm Estimated transmit power from the cell site
+10dB My guess of the panel antenna gain
-100dBm Receive signal level from your test.

Path loss = 27 + 10 + 100 = 137dB
At 700MHz:
http://www.proxim.com/products/knowledge-center/calculations/calculations-free-space-loss
Puts the antenna at about 2 miles away.

There *are* antennas two miles away (and sometimes I connect to them); so
the math isn't as bad as I thought. I also connect to antennas ten and
fifteen miles away, but that's driving distance, so I'd have to look at the
distance as the crow flies, which could be in the less-than-five-mile
range.

On Sun, 19 Feb 2017 15:15:07 -0500, tlvp
wrote:

On Sat, 18 Feb 2017 19:48:00 -0800, Jeff Liebermann wrote:

http://www.evdoforums.com/thread15374.html

I dialed #878# and got:
"Welcome to Verizon Wireless. Your call cannot be completed as
dialed..."

Same here, on the other coast, but with the additional text,
"Announcement for switch [digit] [digit] [digit] dash [digit]."

(Actual digits redacted to "[digit]" for privacy's sake.) Cheers, -- tlvp

I tried it again and got the same thing as you ending in "Announcement
for switch 40-6". 40 is the SID (system identifier) for the San
Francisco Bay area:
http://www.roamingzone.com/sid/
http://ifast.force.com/sid
The 6 is the NID (network identifier). These numbers also agree with
the local VZW tower data as displayed by the NetMonitor app. The
phone is NOT activated and therefore shows everything as roaming.
Operator: 310 00 (Roaming)
Type: CDMA - EvDo Rev A
Carrier: Verizon Wireless
SID: 40 NID: 6 BID: 4864
Signal: -88dBm

I have some better phones (Samsung S4(?) and S6) in my palatial office
that I can try later next week.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 19 Feb 2017 20:44:18 +0000 (UTC), Stijn De Jong
wrote:

On Sat, 18 Feb 2017 23:13:31 -0800, Jeff Liebermann wrote:
Back of the envelope calculation:
+27dBm Estimated transmit power from the cell site
+10dB My guess of the panel antenna gain
-53dBm Receive signal level from your test.

Path loss = 27 + 10 + 53 = 90dB
Calculating the distance where the path loss would be -90dB at 700MHz:
http://www.proxim.com/products/knowledge-center/calculations/calculations-free-space-loss
is about 0.7 miles or about 4,000 ft. The cell tower would need to be
rather close to your location for that to work. Like I said, I'm
suspicious of what you're measuring.

Thanks for showing me how to do the math to approximate the distance to the
antenna based on the received signal strength indication.

Well, I screwed up a little. I left out the antenna gain of your cell
phone, which I assumed to be 0dB at 700MHz. That's probably
optimistic and -3dB would be more reasonable. So, the calcs should be
something like:

+27dBm Estimated transmit power from the cell site
+10dB My guess of the tower panel antenna gain
??dB Calculated path loss
-3dB My guess of the cell phone antenna gain
-53dBm Receive signal level from your test.

Path loss = 27 + 10 - (-3) - (-53) = 93dB
Calculating the distance where the path loss would be -93dB at 700MHz:
http://www.proxim.com/products/knowledge-center/calculations/calculations-free-space-loss
is about 0.94 miles or about 5,000 ft. The cell tower would need to
be rather close to your location or you're getting your signal from
the neighbors.

I must not have stated clearly which is that the only time I get minus
sixty decibels is when the femtotower is in place, where it's only a few
feet from my phone.

The +27dBm (500mw) and +10dBm antenna gain are based on my guess(tm)
of the power per carrier for a real cell tower and a typical panel
antenna and with some reduction in power thanks to transmit power
control. Power levels and antenna gains for DAS (distributed antenna
system), small cell, microcell, picocell, analog repeaters, etc are
much lower.
http://www.rfwireless-world.com/Tutorials/femtocell-vs-picocell-vs-microcell.html
I can build you a table for the various device that will produce more
accurate results.

There *are* antennas two miles away (and sometimes I connect to them); so
the math isn't as bad as I thought. I also connect to antennas ten and
fifteen miles away, but that's driving distance, so I'd have to look at the
distance as the crow flies, which could be in the less-than-five-mile
range.

Also look at the antenna gains on both ends, any RF obstructions
including Fresnel zone blocking, and the accuracy of the signal level
meter in the cell phone. Remember, in RF real RF power, sensitivity,
antenna gains, and path loss, are always worse than calculated.

I don't want to comment on the T-Mobile signal booster due to lack of
experience with the device and general lack of info on what's inside.
If you can supply an FCC ID number, I might be able to excavate
something useful from the FCC ID data dumpster.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558