Verizon wireless - Signal Strength - Competing Cells - Constructive/Destructive Interference

Author

Signal Strength - Competing Cells - Constructive/Destructive Interference

baumgrenze

2007-03-12, 3:33 pm

I am trying to understand why I get such a variable signal (1 tower -
5 towers - 1 tower in the same 1-2 minutes) and so many dropped calls
on my LG VX3200. I'm otherwise very satisfied with the performance of
the phone and just purchased an extended battery for mine and my
wife's to extend their working lifetime.

Yesterday I did a bit of experimentation and walked through the
neighborhood. I saw 5 tower signal strength everywhere I checked. I
walked across the street to the end of my driveway and the signal
plummeted to 1 tower and began to fluctuate. This is 20' from the
nearest part of the house.

As I stood there I thought about how the signal can be seen as
wavelike. There must be points near the border between two cell towers
where the competing signals engage in constructive and destructive
interference. Verizon can claim that they have the space covered with
a strong signal (which I saw as I walked through the neighborhood) but
I can experience the drifting of signal strength as a result of 2
competing cells.

Does this analysis make sense?

If the phone can measure signal strength, it would seem as though it
would be easy to construct a device which measures signal strength and
stores it on a flash memory card for download to Excel. Are such
devices made? It would seem that it would be in Verizon's interest to
be able to loan such a device to a subscriber to place at various
points in the service area to gather data on the quality of the
signal.

Any comments?

Thanks,

baumgrenze

John R. Copeland

2007-03-12, 3:33 pm

"baumgrenze" <baumgrenze@yahoo.com> wrote in message =
news:1173721684.313523.157830@j27g2000cwj.googlegroups.com...
>I am trying to understand why I get such a variable signal (1 tower -
> 5 towers - 1 tower in the same 1-2 minutes) and so many dropped calls
> on my LG VX3200. I'm otherwise very satisfied with the performance of
> the phone and just purchased an extended battery for mine and my
> wife's to extend their working lifetime.
>=20
> Yesterday I did a bit of experimentation and walked through the
> neighborhood. I saw 5 tower signal strength everywhere I checked. I
> walked across the street to the end of my driveway and the signal
> plummeted to 1 tower and began to fluctuate. This is 20' from the
> nearest part of the house.
>=20
> As I stood there I thought about how the signal can be seen as
> wavelike. There must be points near the border between two cell towers
> where the competing signals engage in constructive and destructive
> interference. Verizon can claim that they have the space covered with
> a strong signal (which I saw as I walked through the neighborhood) but
> I can experience the drifting of signal strength as a result of 2
> competing cells.
>=20
> Does this analysis make sense?
>=20
> If the phone can measure signal strength, it would seem as though it
> would be easy to construct a device which measures signal strength and
> stores it on a flash memory card for download to Excel. Are such
> devices made? It would seem that it would be in Verizon's interest to
> be able to loan such a device to a subscriber to place at various
> points in the service area to gather data on the quality of the
> signal.
>=20
> Any comments?
>=20
> Thanks,
>=20
> baumgrenze
>

First, I was amazed that you had signal problems with 5 *towers*.
It's a little unusual to be served simultaneously by five cell towers.
Later, I realized you meant *bars* of signal strength on your display.
Possibly you are getting services from a single cell tower.

Next, forget about the destructive interference idea.
That's a discrete-frequency phenomenon caused by multi-path propagation.
CDMA is a wide-spectrum signal, and multi-path signals do not kill it.
Even better, your handset uses multiple correlators in a "Rake Receiver"
which has the effect of receiving multi-path signals separately,
and combining them so as to actually *improve* reception, not degrade =
it.

Finally, locate the actual cell tower(s) serving your area,
and check for possible shadowing of the area where you lose signal.
Perversely, some of the shadowed areas can be filled in by signals
reflected from houses and buildings, so some places which seem ought
to be in shadow, may in fact have useful coverage by reflections.

And one added item about the handset's display of bars.
Some handsets possibly still show the signal strength per se,
but there's been a trend toward showing signal-to-noise ratio instead.
If your LG shows S/N ratio, then you'd see fewer bars in high-noise =
areas,
even if the actual signal *strength* remained constant.

The Other Funk

2007-03-12, 10:33 pm

Finding the keyboard operational
baumgrenze entered:

>
> If the phone can measure signal strength, it would seem as though it
> would be easy to construct a device which measures signal strength and
> stores it on a flash memory card for download to Excel. Are such
> devices made? It would seem that it would be in Verizon's interest to
> be able to loan such a device to a subscriber to place at various
> points in the service area to gather data on the quality of the
> signal.
>
> Any comments?
>
> Thanks,
>
> baumgrenze

You seem to want my old job of driving around testing antenna patterns,
handoff boundries, etc. It's mind numbingly boring and you can get tons of
data that may or may not be useful.
You should be able to put your phone into a diagnostic mode to see the
signal strength or even better the Ec/Io and map a small area yourself. The
commercial equipment to do this is >$10k. Also you will be able to tell what
cells you are seeing.
Bob (who will not drive thru Chicago at rush hour one more time)

--
--
Coffee worth staying up for - NY Times
www.moondoggiecoffee.com

Larry

2007-03-12, 10:33 pm

"baumgrenze" <baumgrenze@yahoo.com> wrote in
news:1173721684.313523.157830@j27g2000cwj.googlegroups.com:

> Yesterday I did a bit of experimentation and walked through the
> neighborhood. I saw 5 tower signal strength everywhere I checked. I
> walked across the street to the end of my driveway and the signal
> plummeted to 1 tower and began to fluctuate. This is 20' from the
> nearest part of the house.
>
>

I'll take the heat from the CDMA lovers, but I'll say it anyways.....

Have you ever watched analog UHF TV on a portable TV off the little loop
antenna (not the cable, of course)? Did you move around in the room, or
move the TV around, or experience what happens when an aluminum reflector
cloud (airliner) flies overhead? What happened?

Older TV viewers called it "ghosts" because the picture is scanned like
English reads, 525 horizontal lines scanned 30 frames per second from top
to bottom, skipping every other line (which is called interlacing) to
reduce flicker. TV pictures, and your computer screen you're reading
now, is an optical illusion caused by a scanning single beam lighting up
very slow decaying phosphors, but that's another story. The important
part is you saw the main picture, then you saw the "ghosts" off to the
RIGHT of the main picture, one or many of them. The reason they are to
the right is because they arrived LATER than the main picture. This
effect on RF transmission, which, dispite what digital lovers would have
you believe, is still RF transmission, is what your toyphone operates
from. RF is all ANALOG, even though the signal it's passing has been
digitized into 1's and 0's. You can't transmit 1's and 0's, you have to
modulate it on an analog RF carrier. Cellphones use FM modulation, which
isn't really important to seeing this effect.

When you are close to the TV transmitter, the main signal from it is
HUGE. We MADE it HUGE on purpose to try to reduce the ghosts, and allow
you to buy a cheap piece of crap for a receiver with lots of profit
margins. AS distance from the transmitter increases, the main signal
drops off quite rapidly as things get in the way, buildings, bridges,
towers, trees (pine needles just absorb UHF, including cellular signals).
The signal is bouncing all over the place off every piece of metal
anything you can imagine...metal framework of buildings and bridges and
other towers sticking up into the signal path, even though we mounted the
transmit antenna way high up to try to look over them.

Ok, so we have the main DIRECT signal coming straight at you as powerful
as it is (5 bars) on the north side of Elm Street, shooting over the
trees/houses/hill behind the houses. On this side of the street, with
such a strong signal, the reflections off the Main Street Bridge, WXXZ-
FM's 500 tower 2 miles away and the metal framework of the apartment
house down the street is minimal, compared to the great signal you're
getting on the north side of Elm Street. Your connections are great!

However on the OTHER side of Elm Street, the straight shot to the cell
tower (or KMMM-TV, Channel 52 on UHF) is through some trees behind the
houses, the houses themselves and gets bounced around by all the house
wiring that interrupts your DIRECT path. In relation to the signal
reflecting off the Main STreet Bridge and WXXZ-FM (Z99, "The Big Rapper")
tower...the direct signal is much less than it was across the street.
NOW, the relationships between the weaker direct signal and the REFLECTED
signals that have a longer path length arriving LATE interfere with each
other. The TV has awful ghosts on it. AS you move with the cellphone
stuck to your ear, the signal-to-reflection strength fades in and out.
CDMA (to keep the digital boys happy) has error correction schemes and
frequency hopping (which slightly changes the path length, called
"frequency diversity multiplexing". This, however, is simply overrun, at
some point, as the reflected multipath signals become crazy. On the old
FM AMPS phones, just as with the effect on an FM radio or walkie talkie,
you hear the signal fade from fully perfect to way down in the noise
level. We used to move the phone around to a "hotspot" where the signal
we could hear was best. This point is where the reflected signal is IN
PHASE with the direct signal, aiding each other around those damned
houses. On digital, your signal is so delayed by the demodulating,
decoding, synchronizing, decompressing, you don't hear any fading until
the error correction schemes are overrun and the call was dumped as being
unservicable.

In other radio systems, like wireless microphones at a rock concert,
multiple antennas are used to receive the mic signal SPACED multiples of
1/4 wavelength at their frequency from each other, sticking out two sides
of the mic receiver. This is another method of dealing with multipath
called SPACE diversity. NASA uses it to hear Mars satellites, except
their spacing is from one side of the planet to the other, thousands of
miles apart. You can see space diversity antenna arrays on wireless
internet routers sold in any store. They have 2 or 3 or 4 or more
antennas spaced around the box. A computer circuit called a "voter",
figures out which antenna has the best signal from your laptop,
CONTINUOUSLY, and switches antennas to the best one for the signal.
Multipath just eats the digital signals on 2400 Mhz 802.11x wifi
something awful because there is no POWERful transmitter. Watch the wifi
signal meter as you move a metal cookie sheet around your computer room.
It makes it go crazy.

We have exacerbated this problem squeezing more and more revenue makers
into smaller and smaller cellular towers. Everyone is running (except
me, of course) so low power, like .15 watts max, that a receiver next
door would see 20 multipath signals from your toyphone. We bagphone boys
run POWER for a reason...(c;...though many of them don't know why.

Larry
--
POWER is our friend....a kilowatt beats a milliwatt hands down on any
frequency!

Larry

2007-03-12, 10:33 pm

"baumgrenze" <baumgrenze@yahoo.com> wrote in news:1173721684.313523.157830
@j27g2000cwj.googlegroups.com:

> It would seem that it would be in Verizon's interest to
> be able to loan such a device to a subscriber to place at various
> points in the service area to gather data on the quality of the
> signal.
>

NO WAY! That would force them to admit something was wrong! They'll never
do that. It's always your phone that's at fault. Turn it off and turn it
back on and all problems are cured...(c;

Larry
--

Larry

2007-03-12, 10:33 pm

"John R. Copeland" <jcopelan@columbus.rr.aol.com> wrote in news:45f5b216$0
$24695$4c368faf@road
runner.com:

> That's a discrete-frequency phenomenon caused by multi-path propagation.
>

See? Bullshit. Multipath happens on EVERY frequency it switches to. It
only switches between very-narrowly-spaced 800 or 1900 Mhz frequency
channels. It's all they have assigned.

Larry
--
How much price inflation is caused by illegal
aliens gobbling up goods and services, creating
shortages for the natives? I heard 40%!

The Other Funk

2007-03-12, 10:33 pm

Finding the keyboard operational
Larry entered:

> "baumgrenze" <baumgrenze@yahoo.com> wrote in
> news:1173721684.313523.157830@j27g2000cwj.googlegroups.com:
>
>
> I'll take the heat from the CDMA lovers, but I'll say it anyways.....
>
< snip of a great description of what multipath is but ignores how CDMA
receivers work>
Larry, go look up what a rake receiver is and get back to us. Until then
pplease don't post incorrect and incomplete information.
Just to help you out, yes the RF is analog but the beauty is in the digital
domain.
Bob
--
--
Coffee worth staying up for - NY Times
www.moondoggiecoffee.com

Larry

2007-03-12, 10:33 pm

"The Other Funk" <bobbie@moondoggie.com> wrote in
news:cFlJh.2010$vV3.71@trndny09:

> Just to help you out, yes the RF is analog but the beauty is in the
> digital domain.
>

Then his signal, no matter how much multipath he encounters...would be
perfect.

It isn't.......bullshit.

Larry
--
How much price inflation is caused by illegal
aliens gobbling up goods and services, creating
shortages for the natives? I heard 40%!

The Other Funk

2007-03-12, 10:33 pm

Finding the keyboard operational
Larry entered:

> "The Other Funk" <bobbie@moondoggie.com> wrote in
> news:cFlJh.2010$vV3.71@trndny09:
>
>
> Then his signal, no matter how much multipath he encounters...would be
> perfect.
>
> It isn't.......bullshit.
>
> Larry

Did you look at how a rake receiver works? No one ever said that the
received signal was perfect. You introduced that strawman.
Look at it this way. Say you have a group of very directional antennae. You
aim one at the direct path and others at the direction the multipath signal
comes from. Then by adjusting for the time delays, you sum all those
signals. Wouldn't you have a greater signal then from just one path?
Bob

--
--
Coffee worth staying up for - NY Times
www.moondoggiecoffee.com

Ness_net

2007-03-13, 4:33 am

And, Larry demonstrates a COMPLETE LACK of understanding CDMA.

I have covered rake receivers here multiple times before.

Larry either just doesn't get it or does and is simply being obtuse.

But, the FACTS are as stated by John.

100% accurate.

Larry???? 100% WRONG!!

Oh, as an added bonus, CDMA phones are capable of using multiple towers
at the same, as well as benefiting from multipath.

"Larry" <noone@home.com> wrote in message news:Xns98F1C5A1EE55
Bnoonehomecom@208.49.80.253...
> "John R. Copeland" <jcopelan@columbus.rr.aol.com> wrote in news:45f5b216$0
> $24695$4c368faf@road
runner.com:
>
>
> See? Bullshit. Multipath happens on EVERY frequency it switches to. It
> only switches between very-narrowly-spaced 800 or 1900 Mhz frequency
> channels. It's all they have assigned.
>
>
> Larry
> --
> How much price inflation is caused by illegal
> aliens gobbling up goods and services, creating
> shortages for the natives? I heard 40%!
>

Ness_net

2007-03-13, 4:33 am

It has NOTHING to do with "CDMA lovers"
I and others actually understand CDMA and how it works.
Sorry Larry, the below is correct in the analog RF world.

With CDMA, it sinply ain't as you say below.

You are 100% WRONG!!!!!!!

A rake receiver is a radio receiver designed to counter the effects of multipath fading. It does this by using several
"sub-receivers" each delayed slightly in order to tune in to the individual multipath components. Each component is
decoded independently, but at a later stage combined in order to make the most use of the different transmission
characteristics of each transmission path. This could very well result in higher signal-to-noise ratio (or Eb/N0) in a
multipath environment than in a "clean" environment.

In a RAKE receiver, one RAKE finger is assigned to each multipath, thus maximizing the amount of received signal energy.
Each of these different paths are combined to form a composite signal that is expected to have substantially better
characteristics for the purpose of demodulation than just the a single path.

The rake receiver is designed to optimally detected a CDMA signal transmitted over a dispersive multipath channel. It is
an extension of the concept of the matched filter. In a multipath channel, delayed reflections interfere with the direct
signal. However, a CDMA signal suffering from multipath dispersion can be detected by a rake receiver. This receiver
optimally combines signals received over multiple paths.

Do I need to continue??????

"Larry" <noone@home.com> wrote in message news:Xns98F1C509FA82
8noonehomecom@208.49.80.253...
> "baumgrenze" <baumgrenze@yahoo.com> wrote in
> news:1173721684.313523.157830@j27g2000cwj.googlegroups.com:
>
>
> I'll take the heat from the CDMA lovers, but I'll say it anyways.....
>
> Have you ever watched analog UHF TV on a portable TV off the little loop
> antenna (not the cable, of course)? Did you move around in the room, or
> move the TV around, or experience what happens when an aluminum reflector
> cloud (airliner) flies overhead? What happened?
>
> Older TV viewers called it "ghosts" because the picture is scanned like
> English reads, 525 horizontal lines scanned 30 frames per second from top
> to bottom, skipping every other line (which is called interlacing) to
> reduce flicker. TV pictures, and your computer screen you're reading
> now, is an optical illusion caused by a scanning single beam lighting up
> very slow decaying phosphors, but that's another story. The important
> part is you saw the main picture, then you saw the "ghosts" off to the
> RIGHT of the main picture, one or many of them. The reason they are to
> the right is because they arrived LATER than the main picture. This
> effect on RF transmission, which, dispite what digital lovers would have
> you believe, is still RF transmission, is what your toyphone operates
> from. RF is all ANALOG, even though the signal it's passing has been
> digitized into 1's and 0's. You can't transmit 1's and 0's, you have to
> modulate it on an analog RF carrier. Cellphones use FM modulation, which
> isn't really important to seeing this effect.
>
> When you are close to the TV transmitter, the main signal from it is
> HUGE. We MADE it HUGE on purpose to try to reduce the ghosts, and allow
> you to buy a cheap piece of crap for a receiver with lots of profit
> margins. AS distance from the transmitter increases, the main signal
> drops off quite rapidly as things get in the way, buildings, bridges,
> towers, trees (pine needles just absorb UHF, including cellular signals).
> The signal is bouncing all over the place off every piece of metal
> anything you can imagine...metal framework of buildings and bridges and
> other towers sticking up into the signal path, even though we mounted the
> transmit antenna way high up to try to look over them.
>
> Ok, so we have the main DIRECT signal coming straight at you as powerful
> as it is (5 bars) on the north side of Elm Street, shooting over the
> trees/houses/hill behind the houses. On this side of the street, with
> such a strong signal, the reflections off the Main Street Bridge, WXXZ-
> FM's 500 tower 2 miles away and the metal framework of the apartment
> house down the street is minimal, compared to the great signal you're
> getting on the north side of Elm Street. Your connections are great!
>
> However on the OTHER side of Elm Street, the straight shot to the cell
> tower (or KMMM-TV, Channel 52 on UHF) is through some trees behind the
> houses, the houses themselves and gets bounced around by all the house
> wiring that interrupts your DIRECT path. In relation to the signal
> reflecting off the Main STreet Bridge and WXXZ-FM (Z99, "The Big Rapper")
> tower...the direct signal is much less than it was across the street.
> NOW, the relationships between the weaker direct signal and the REFLECTED
> signals that have a longer path length arriving LATE interfere with each
> other. The TV has awful ghosts on it. AS you move with the cellphone
> stuck to your ear, the signal-to-reflection strength fades in and out.
> CDMA (to keep the digital boys happy) has error correction schemes and
> frequency hopping (which slightly changes the path length, called
> "frequency diversity multiplexing". This, however, is simply overrun, at
> some point, as the reflected multipath signals become crazy. On the old
> FM AMPS phones, just as with the effect on an FM radio or walkie talkie,
> you hear the signal fade from fully perfect to way down in the noise
> level. We used to move the phone around to a "hotspot" where the signal
> we could hear was best. This point is where the reflected signal is IN
> PHASE with the direct signal, aiding each other around those damned
> houses. On digital, your signal is so delayed by the demodulating,
> decoding, synchronizing, decompressing, you don't hear any fading until
> the error correction schemes are overrun and the call was dumped as being
> unservicable.
>
> In other radio systems, like wireless microphones at a rock concert,
> multiple antennas are used to receive the mic signal SPACED multiples of
> 1/4 wavelength at their frequency from each other, sticking out two sides
> of the mic receiver. This is another method of dealing with multipath
> called SPACE diversity. NASA uses it to hear Mars satellites, except
> their spacing is from one side of the planet to the other, thousands of
> miles apart. You can see space diversity antenna arrays on wireless
> internet routers sold in any store. They have 2 or 3 or 4 or more
> antennas spaced around the box. A computer circuit called a "voter",
> figures out which antenna has the best signal from your laptop,
> CONTINUOUSLY, and switches antennas to the best one for the signal.
> Multipath just eats the digital signals on 2400 Mhz 802.11x wifi
> something awful because there is no POWERful transmitter. Watch the wifi
> signal meter as you move a metal cookie sheet around your computer room.
> It makes it go crazy.
>
> We have exacerbated this problem squeezing more and more revenue makers
> into smaller and smaller cellular towers. Everyone is running (except
> me, of course) so low power, like .15 watts max, that a receiver next
> door would see 20 multipath signals from your toyphone. We bagphone boys
> run POWER for a reason...(c;...though many of them don't know why.
>
>
> Larry
> --
> POWER is our friend....a kilowatt beats a milliwatt hands down on any
> frequency!
>
>

baumgrenze

2007-03-13, 4:33 am

Thank you everybody for your input.

Here are some more basic questions from a casual user of cellphone
technology.

1) How far from my point of use can a functional cell tower be?

2) Is the ability of a given tower to provide service to an individual
subscriber a function of the number of calls it it handling?

3) If so, does it attempt to pass a call or an attempt to call off to
a neighboring tower if it is a functional distance away?

4) If a subscriber finds himself midway between two towers can he
experience variable service because the phone has trouble deciding
which tower to use?

Someone suggested looking for towers and for multipath reflectors.

I am located on the flats, not far from San Francisco Bay, i.e., about
1/2 mile west of 101 and very close to the Oregon Expressway.

Verizon is not willing to say where their towers in my vicinity are
located. I know of a tower in the flagpole at the fire station at
Newell and Embarcadero (ca 0.5 miles) and another in the steeple of
the Congregational Church at Louis and Embarcadero (ca 0.4 miles.) I
don't know if Verizon uses either of them. I have not seen cell towers
elsewhere in my neighborhood.

Are providers required to register cell phone tower locations with
some public agency? Can I gain access to location information in that
way?

Should I consider installing an antenna/repeater product to improve
reception inside my house?

Thanks,

baumgrenze

baumgrenze

2007-03-13, 4:33 am

Larry

2007-03-13, 10:33 am

"The Other Funk" <bobbie@moondoggie.com> wrote in
news:YpnJh.1907$Bi2.482@trnddc01:

> Did you look at how a rake receiver works? No one ever said that the
> received signal was perfect. You introduced that strawman.
> Look at it this way. Say you have a group of very directional
> antennae. You aim one at the direct path and others at the direction
> the multipath signal comes from. Then by adjusting for the time
> delays, you sum all those signals. Wouldn't you have a greater signal
> then from just one path?
>

No, you wouldn't. Air doesn't conduct RF well at all. It absorbs it.
Anything you can do to concentrate RF on the shortest possible path
increases the signal at the receiver.

You can't adjust the time delays because they are always changing and the
multipaths are always changing, especially on a cellular system where the
transmitter phone is moving very fast through the multipath minefield.

One of our greatest mistakes was putting cellular, and later PCS, so far
up the RF spectrum. It was done for a variety of reasons related to
antenna size, available spectrum space, telephone company politics trying
to prevent losing their IMTS cash cows, etc. VHF signals propagate much
better, and with lots less attenuation, than UHF. Find a TV station on
channels 2-6 and see how much better the signal is to that portable TV.
TV stations all wanted to be BELOW the FM radio band, channels 2-6 for
this reason. Cellular doesn't have this luxury. We're hogtied with 850
or 1900 Mhz, damned near in the microwave bands and very short ranged,
the reason the signal level drops so fast as you move away from the cell.

Larry

2007-03-13, 10:33 am

"baumgrenze" <baumgrenze@yahoo.com> wrote in
news:1173766863.784236.257220@n33g2000cwc.googlegroups.com:

> Here are some more basic questions from a casual user of cellphone
> technology.
>
> 1) How far from my point of use can a functional cell tower be?

PCS on 1900 Mhz - 2 miles. Cellular on 850 Mhz - 3-4 miles IF YOU'RE
OUTSIDE. Range drops in hills or city canyons of steel buildings. All
cellular/PCS is line-of-sight. If you don't have a clear shot at the
tower, It ain't gonna happen. There is no over-the-hill-or-horizon on
these frequencies.
>
> 2) Is the ability of a given tower to provide service to an individual
> subscriber a function of the number of calls it it handling?

Yes. The reason for all the digital hype is many users can use the same
channel at once because the cellphone is transmitting data in bursts, as
needed, switching channels very fast to find a spot to send it called
spread spectrum. It's very fault tolerant and can correct errors...up to
a point. You hear the point as your phone starts buzzing and beeping
decoding pieces and bits of the data stream or dropping in and out.

>
> 3) If so, does it attempt to pass a call or an attempt to call off to
> a neighboring tower if it is a functional distance away?

Overloaded digital systems simply don't make the call in the first place
until it can find a space to put you. Because there are so many spaces
available, unlike the old analog systems, this rarely happens until
something catastrophic happens that creates a storm of calls, at which
point the whole system breaks down. Making a call as a hurricane
approaches Charleston, for instance, becomes catatonic.

>
> 4) If a subscriber finds himself midway between two towers can he
> experience variable service because the phone has trouble deciding
> which tower to use?
>
>

Tower spacing is an art form few cheapskate cellphone companies are good
at. The landscape of reflecting surfaces, mountains, attenuating trees
is very complex and the models used to determine any transmitter's
effective field strength are only so good. Actual experience of the
users is always less than the models because the models can't take into
account that Boeing 747 your signal is reflecting off as it climbs out of
the nearby airport or the rain or the other traffic around you. Even the
heat of the sun coming off a hot parking lot creates RF noise that raises
the noise floor and reduces range of RF devices. This is especially true
of satellite TV, etc. Noise and attenuation is your enemy.

In reality, you end up with towers that are too far apart for comfort,
for a variety of social, political and MOSTLY economic reasons. In any
locality, you'll find dead zones of poor coverage on Carrier A that
Carrier B has covered from a different place. For a time, the carriers
got together and shared resources, allowing you to roam IN MARKET when
your carrier went tits up at a location. Reality soon set in as the
roaming went bananas across the country because everyone's coverage
sucked so bad. The cure was the PRL so the company could FORCE your
phone to ignore a perfectly good signal when its allowed connections,
listed in the PRL, were too awful to use. So, you end up standing in the
shadow of a half-loaded cellphone tower with a dead or poorly working
phone that COULD be using one of those channels, solid, but is forbidden
from doing so to save your carrier a few pennies. Service from all of
them is poor in some areas because noone is forcing them to do what's
right and allow in-market roaming if they don't have smooth coverage
across their licensed areas. FCC does nothing to protect the customers
because it's in cellular's back pocket...even though cellular is using
the PUBLIC's airwaves. It doesn't have to be this way.

Back in the AMPS days, the carriers didn't control the phones. A phone
set to STD A/B (or STD B/A depending on which system you were on) would
roam over to the other guys system and make the calls. Cellular's weapon
to combat this practice was to charge you an awful roaming rate, several
dollars per minute, which kept the users' phones set to HOME ONLY, except
for the very rich and businesses that had to have service.

Larry
--

Dennis Ferguson

2007-03-13, 12:33 pm

On 2007-03-13, Michael D. Sullivan <userid@camsul.example.invalid> wrote:
> On 3/12/2007 4:03 PM, John R. Copeland wrote:
>
> Actually, in CDMA S/N ratio is pretty much irrelevant. The factor used
> in determining call quality is Eb/N0. Damned if I know what it stands
> for, though.

The Eb is the energy per bit, i.e. the signal power. No is the spectral
density of noise, i.e. the noise power. Eb/No is essentially a fancy
way of saying signal-to-noise ratio.

Dennis Ferguson

Dennis Ferguson

2007-03-13, 3:33 pm

On 2007-03-12, Larry <noone@home.com> wrote:
> "John R. Copeland" <jcopelan@columbus.rr.aol.com> wrote in news:45f5b216$0
> $24695$4c368faf@road
runner.com:
>
>
> See? Bullshit. Multipath happens on EVERY frequency it switches to. It
> only switches between very-narrowly-spaced 800 or 1900 Mhz frequency
> channels. It's all they have assigned.

Larry, you should know that the CDMA we use for phone service isn't
frequency-hopping spread spectrum, it is direct sequence spread spectrum.
It doesn't switch frequencies, it transmits a signal that is 1.23 MHz
wide to carry a very small bit rate.

For multipath to effect all parts of a signal that wide the same way
the difference in path lengths would have to be small compared to
250 meters, the wavelength of 1.23 MHz. With a path length difference
of 250 meters you are guaranteed that if there is a null somewhere in
the 1.23 MHz there will be a peak somewhere else, and as the difference
increases you'll get more peaks and nulls. Because of this, by far
the most common effect of multipath isn't that the whole signal goes
away but rather that the signal is distorted.

The technique mentioned to you is a time-domain method of removing
that distortion.

Dennis Ferguson

baumgrenze

2007-03-13, 3:33 pm

Here's another thought.

If I construct a small parabolic reflector that I can slip on to the
antenna on my cell phone, made, say, of fine mesh stainless steel,
will it allow me to sweep around in a given location to try to find
the tower that is supplying my service?

Won't this technique allow me to determine the direction of the
strongest signal, as well as to find some somewhat weaker reflections.

My guess is that I should start with 'dish' that has a diameter
similar to the length of my antenna, am I right?

Thanks,

baumgrenze

Larry

2007-03-14, 7:33 am

Dennis Ferguson <dcferguson@pacbell.net> wrote in
news:slrnevdr3m.8c.dcferguson@akit-ferguson.com:

> Dennis Ferguson
>

The magic didn't work, yesterday. My new Moto M800 1/4 watt bagphone
sucked in the forest by itself. I'm returning it to Alltel today.

It's crowning glory is its wonderful speakerphone you can actually hear
as well as its ringer. But, alas, a 1/4 watt CDMA phone (actually, I'm
convinced from all its exactly similar commands, a V60i in a big box,
isn't worth the hassle of carrying this beast around and constantly
plugging it in because it's such a power hog. The audio amp must be
running class A to suck up the big battery so fast, as well as leaving
the lights on all the time. Stupid, Moto, stupid.

Back she goes, CDMA magic or no CDMA magic.

Question for you CDMA experts.....
If CDMA is such cellular magic, why is only 3 companies in the USA using
it....and the rest of the civilized world using GSM?? There's no CDMA I
know of in Europe, at all.

Maybe the Illuminati of the New World Order can set a worldwide cellular
standard so your phone works anywhere, any time, when the Freemasons take
over.

Larry
--

Larry

2007-03-14, 7:33 am

"Ness_net" <richard@nomore.damn.spam.nessnet.com> wrote in
news:x9ydnRW4JcMg1mr
YnZ2dnUVZ_uuqnZ2d@gi
ganews.com:

> With CDMA distance is adjustable to help optimize the system.

With CDMA, distance is adjustable to help optimize the profits.

There. That's more correct.

Larry
--

The Other Funk

2007-03-14, 7:33 am

Finding the keyboard operational
Larry entered:

> "Ness_net" <richard@nomore.damn.spam.nessnet.com> wrote in
> news:x9ydnRW4JcMg1mr
YnZ2dnUVZ_uuqnZ2d@gi
ganews.com:
>
>
> With CDMA, distance is adjustable to help optimize the profits.
>
> There. That's more correct.
>
> Larry

Optimized system = optimized profits.
You don't make any money on calls not made.

--
--
Coffee worth staying up for - NY Times
www.moondoggiecoffee.com

The Other Funk

2007-03-14, 7:33 am

Finding the keyboard operational
Larry entered:

> Dennis Ferguson <dcferguson@pacbell.net> wrote in
> news:slrnevdr3m.8c.dcferguson@akit-ferguson.com:
>
>
> The magic didn't work, yesterday. My new Moto M800 1/4 watt bagphone
> sucked in the forest by itself. I'm returning it to Alltel today.
>
> It's crowning glory is its wonderful speakerphone you can actually
> hear as well as its ringer. But, alas, a 1/4 watt CDMA phone
> (actually, I'm convinced from all its exactly similar commands, a
> V60i in a big box, isn't worth the hassle of carrying this beast
> around and constantly plugging it in because it's such a power hog.
> The audio amp must be running class A to suck up the big battery so
> fast, as well as leaving the lights on all the time. Stupid, Moto,
> stupid.
>
> Back she goes, CDMA magic or no CDMA magic.
>
> Question for you CDMA experts.....
> If CDMA is such cellular magic, why is only 3 companies in the USA
> using it....and the rest of the civilized world using GSM?? There's
> no CDMA I know of in Europe, at all.
>
> Maybe the Illuminati of the New World Order can set a worldwide
> cellular standard so your phone works anywhere, any time, when the
> Freemasons take over.
>
> Larry

GSM, which uses a time domain protocl, is being replaced by UMTS which uses
a spread spectrum signal aka CDMA.

--
--
Coffee worth staying up for - NY Times
www.moondoggiecoffee.com

The Other Funk

2007-03-14, 7:33 am

Finding the keyboard operational
baumgrenze entered:

> On Mar 13, 3:12 pm, "John R. Copeland" <jcope...@columbus.rr.aol.com>
> wrote:
>
> Thanks for the advice regarding "diagnostic mode." I spent some time
> trying to learn about this. I gather that Verizon won't be helpful
> since it might suggest that I want to use the phone elsewhere. I
> gather, too, that it is important to know how to get back out of
> diagnostic mode as well as how to get in.
>
> thanks
>
> baumgrenze
>
Usually in the tool menu there is a hidden command to get into the
diagnostics. Most often you will see menu options numbered 1 to whateverr
but if you press 0 you get the diagnostic menu. Then you have a display
option. To return to normal, turn the phone off and back on. You will need
some help interpeting the numbers.
WARNING: I do not know that this will work for every phone.
Bob
--
--
Coffee worth staying up for - NY Times
www.moondoggiecoffee.com

Dennis Ferguson

2007-03-14, 12:33 pm

On 2007-03-14, Larry <noone@home.com> wrote:
> If CDMA is such cellular magic, why is only 3 companies in the USA using
> it....and the rest of the civilized world using GSM?? There's no CDMA I
> know of in Europe, at all.

UMTS, the European 3G standard, is also CDMA, though its channels are
5 MHz wide rather than 1.25 MHz. Cingular's high speed data service
is the same. There are a lot of operators in Europe running UMTS
now, some provide no GSM service at all.

GSM was the first digital standard to get written down (before TDMA,
before IS-95 CDMA), and European governments simply mandated that
all wireless companies use it. The FCC decided not to get involved
in picking a digital standard which is why the USA ended up with
several of them. Originally none of the US companies thought GSM was
a good idea for technical reasons, which is why they all originally
picked something else, but the European mandate gave the companies
doing GSM equipment development a big enough captive market that they've
apparently managed to turn that sow's ear into something approximating
a silk purse.

In Asia (also civilized, despite rumors to the contrary) there are
a number of CDMA2000 operators as well, though a lot of them seem to
be abandoning it in favor of UMTS. Everyone thinks CDMA is a good
idea now, apparently, though there are enough incompatible CDMA standards
that you still can't buy one phone which works everywhere.

I'm sorry about the M800; it seemed like such a good thing on paper.

Dennis Ferguson

SlobbyDon

2007-03-14, 10:33 pm

Larry wrote:
> Dennis Ferguson <dcferguson@pacbell.net> wrote in
> news:slrnevdr3m.8c.dcferguson@akit-ferguson.com:
>
>
> Maybe the Illuminati of the New World Order can set a worldwide
> cellular standard so your phone works anywhere, any time, when the
> Freemasons take over.
>

I'm sure that's coming. This reminds me of an old Lois & Clark episode
where it was a capital offense not to own a phone! The villain Tempus
was using the landline phone system to subliminally control everyone.
That was in the early nineties when cellphones were rare.

--
SlobbyDon

Larry

2007-03-14, 10:33 pm

Dennis Ferguson <dcferguson@pacbell.net> wrote in
news:slrnevg7i5.86.dcferguson@akit-ferguson.com:

> I'm sorry about the M800; it seemed like such a good thing on paper.
>
> Dennis Ferguson
>
>

Thanks, Dennis. I lost a couple of hours running back and forth. Alltel's
people, today, just took it back...cancelled my 2-year contract...and put
my V60i back on Alltel with absolutely no hassle whatsoever. Noone in the
store, of course, had any idea it was so low powered, but I'm sure the
company knows....at least I hope they know.

3 of the sales people had never seen a bagphone, so I brought an Alltel
REAL AMPS bagphone in from my car that was half the size of the M800 beast.
I carry one in every vehicle for emergency comms in the boonies. It made
me feel awful "old" these kids in the cellphone business didn't know what a
carphone or bagphone even looked like....(sigh)

Larry
--
POWER is still our friend....

Larry

2007-03-14, 10:33 pm

"SlobbyDon" < slobby_NIXSPAMdon@ma
il.ru> wrote in news:zdYJh.12734$tD2.4763
@newsread1.news.pas.earthlink.net:

> was using the landline phone system to subliminally control everyone.

Do a Google search on:

Verichip

and be VERY afraid.....

Larry
--
Roll up to the long checkout line....
Yell, "ICE RAID!"
It's your turn to load the grocery belt...(c;

Larry

2007-03-14, 10:33 pm

"The Other Funk" <bobbie@moondoggie.com> wrote in news:D6RJh.1309$qe5.1230
@trnddc05:

> You don't make any money on calls not made.
>
>

Has Verizon started automatically crediting you for dropped calls like
Alltel does?

Larry
--
Roll up to the long checkout line....
Yell, "ICE RAID!"
It's your turn to load the grocery belt...(c;

Larry

2007-03-14, 10:33 pm

"The Other Funk" <bobbie@moondoggie.com> wrote in
news:TdRJh.1311$qe5.343@trnddc05:

> Finding the keyboard operational
> baumgrenze entered:
>
> Usually in the tool menu there is a hidden command to get into the
> diagnostics. Most often you will see menu options numbered 1 to
> whateverr but if you press 0 you get the diagnostic menu. Then you
> have a display option. To return to normal, turn the phone off and
> back on. You will need some help interpeting the numbers.
> WARNING: I do not know that this will work for every phone.
> Bob
> --
> --
> Coffee worth staying up for - NY Times
> www.moondoggiecoffee.com
>
>

On Motorola phones, try ##DEBUG (##33284) The last 4 won't show on the
display, an indication the phone took it as a command. Press the center
menu key, then left function key under the display to toggle it on and
off. It'll stay in debug mode forever, even if you shut it off.

Larry
--
Roll up to the long checkout line....
Yell, "ICE RAID!"
It's your turn to load the grocery belt...(c;

The Other Funk

2007-03-15, 12:33 pm

Finding the keyboard operational
Larry entered:

> "SlobbyDon" < slobby_NIXSPAMdon@ma
il.ru> wrote in
> news:zdYJh.12734$tD2.4763 @newsread1.news.pas.earthlink.net:
>
>
> Do a Google search on:
>
> Verichip
>
> and be VERY afraid.....
>
> Larry

For once Larry you don't come across as a raving, nut case, lunatic. It must
be time to replace your tracking device.
Bob

--
--
Coffee worth staying up for - NY Times
www.moondoggiecoffee.com

Abanedsterjo1

2007-03-16, 8:06 am

Jessica Alba In Anal Action Movie!
http://Jessica-Alba-In-Anal-Action-...hp?movie=394964

baumgrenze

2007-03-22, 4:33 am

I'm back again!

I tried entering "0" on the main menu. What I see on the screen is
text reading "Service Code" and 6 question marks (??????) which
suggests I need to know what code to enter to move forward. It this
perhaps something in the Verizon software for this phone?

Sorry I'm so intermittent with my attention to this thread. Perhaps it
is related to the cell phone signal availability?

baumgrenze

On Mar 14, 3:43 am, "The Other Funk" <bob...@moondoggie.com> wrote:
> Finding the keyboard operational
> baumgrenzeentered:
>
>
>
>
>
> Usually in the tool menu there is a hidden command to get into the
> diagnostics. Most often you will see menu options numbered 1 to whateverr
> but if you press 0 you get the diagnostic menu. Then you have a display
> option. To return to normal, turn the phone off and back on. You will need
> some help interpeting the numbers.
> WARNING: I do not know that this will work for every phone.
> Bob
> --
> --
> Coffee worth staying up for - NY Timeswww.moondoggiecoffee.com

The Other Funk

2007-03-22, 12:33 pm

Finding the keyboard operational
baumgrenze entered:
[color=darkred]
> I'm back again!
>
> I tried entering "0" on the main menu. What I see on the screen is
> text reading "Service Code" and 6 question marks (??????) which
> suggests I need to know what code to enter to move forward. It this
> perhaps something in the Verizon software for this phone?
>
> Sorry I'm so intermittent with my attention to this thread. Perhaps it
> is related to the cell phone signal availability?
>
> baumgrenze
>
> On Mar 14, 3:43 am, "The Other Funk" <bob...@moondoggie.com> wrote:
try 000000
Bob
--
--
Coffee worth staying up for - NY Times
www.moondoggiecoffee.com

baumgrenze

2007-03-22, 3:33 pm

Thank you Bob!

000000 Worked!

Here are the menu items that display:

1) Service Program 031 04252130

2) Field Tests
3) Force Mode
4) Force Call
5) Data
6) SMS
7) H/W Test
8) FCC Test

I tried (1) and the display responded "031 04252130"

When I selected "Exit" the phone rebooted.

I decided it was time for more advice before I ran something I
shouldn't.

Thanks,

baumgrenze

On Mar 22, 7:10 am, "The Other Funk" <bob...@moondoggie.com> wrote:

>
> try 000000
> Bob
> --

Dennis Ferguson

2007-03-23, 4:33 am

On 2007-03-22, baumgrenze <baumgrenze@yahoo.com> wrote:
> 3) Force Mode

This one is occasionally useful, to try out the AMPS or (more often) to
keep the phone on a marginal but working CDMA signal rather than a
stronger but non-working AMPS service. Everyhing else in there does very
little which needs doing.

Dennis Ferguson

Larry

2007-03-23, 4:33 am

Dennis Ferguson <dcferguson@pacbell.net> wrote in
news:slrnf06e7l.8d.dcferguson@akit-ferguson.com:

> stronger but non-working AMPS service.

Where's that?? AMPS always works better'n CDMA in South Carolina....out of
the city.

Think they're trashing it trying to get you to stop using it??

Larry
--
Message for Comcrap Internet Customers:
http://tinyurl.com/3ayl9c
Unlimited Service my XXX.....(d^:)

Dennis Ferguson

2007-03-23, 12:33 pm

On 2007-03-23, Larry <noone@home.com> wrote:
> Dennis Ferguson <dcferguson@pacbell.net> wrote in
> news:slrnf06e7l.8d.dcferguson@akit-ferguson.com:
>
>
> Where's that?? AMPS always works better'n CDMA in South Carolina....out of
> the city.
>
> Think they're trashing it trying to get you to stop using it??

It's in Zihuatanejo, Mexico, I don't think they are organized enough
to do that.

It may be my phone. There is both AMPS and CDMA service available there,
and both of them work when the signals are strong. The problem is that
in marginal areas my phone will switch from a 1-bar CDMA signal to a 2-bar
AMPS signal, and while the 1-bar CDMA signal still works okay my phone
doesn't have enough oomph for the 2-bar AMPS tower to hear it well.
Either calls fail, or the person I call only hears static.

I used to just leave the phone set to CDMA-only, but I eventually realized
that in a lot of the small towns I was visiting on day trips there were
people using cellphones even though there was neither CDMA nor GSM service
detectable on my phones. Some places only have TDMA/AMPS service, so
AMPS is still useful even though it gets in the way when CDMA is
available.

Dennis Ferguson

Larry

2007-03-24, 7:33 am

Dennis Ferguson <dcferguson@pacbell.net> wrote in
news:slrnf07vrp.6s.dcferguson@akit-ferguson.com:

> Some places only have TDMA/AMPS service, so
> AMPS is still useful even though it gets in the way when CDMA is
> available.
>

How do you figure that? AMPS channels are not used for CDMA, even if there
is no AMPS signals in the air.

http://www.strategis.ic.gc.ca/epic/...apj/rss129.pdf/
$FILE/rss129.pdf
US and Canada on same channel pairs

Larry
--
Message for Comcrap Internet Customers:
http://tinyurl.com/3ayl9c
Unlimited Service my XXX.....(d^:)

Dennis Ferguson

2007-03-24, 10:33 pm

On 2007-03-24, Larry <noone@home.com> wrote:
> Dennis Ferguson <dcferguson@pacbell.net> wrote in
> news:slrnf07vrp.6s.dcferguson@akit-ferguson.com:
>
>
> How do you figure that? AMPS channels are not used for CDMA, even if there
> is no AMPS signals in the air.

That's very true, AMPS and CDMA don't interfere. My problem is that my
phone will switch from a weak but still working CDMA signal to an AMPS
signal which shows an extra bar of signal strength on the phone but which
turns out to be unuseable by my phone when you actually try to make a call.

To keep the phone on the CDMA signal I have to tell it to ignore AMPS.

Dennis Ferguson

The Other Funk

2007-03-24, 10:33 pm

Finding the keyboard operational
baumgrenze entered:

> Thank you Bob!
>
> 000000 Worked!
>
> Here are the menu items that display:
>
> 1) Service Program 031 04252130
> 2) Field Tests
> 3) Force Mode
> 4) Force Call
> 5) Data
> 6) SMS
> 7) H/W Test
> 8) FCC Test
>
> I tried (1) and the display responded "031 04252130"
>
> When I selected "Exit" the phone rebooted.
>
> I decided it was time for more advice before I ran something I
> shouldn't.
>
> Thanks,
>
> baumgrenze
try 2. you might see something like a bunch of numbers or abbreviations and
numbers.
Stay away from numbers5 thru 7. And remember I am not responsible for what
happens to your phone. If your phone locks up, pulling the battery should
put it back to normal.

--
--
Coffee worth staying up for - NY Times
www.moondoggiecoffee.com

Larry

2007-03-24, 10:33 pm

Dennis Ferguson <dcferguson@pacbell.net> wrote in
news:slrnf0b8b6.82.dcferguson@akit-ferguson.com:

> To keep the phone on the CDMA signal I have to tell it to ignore AMPS.
>

Since we started talking about AMPS on this thread, even I have become a
traitor, I'm afraid. Too many E815 users told me how great a phone it
was, so I gave up my V60i trimode with AMPS for a new E815 with all the
toys. E815 has an external antenna jack and a nice, old-fashioned 800
Mhz pull up full-sized antenna to help it get more range. My
cellantenna.com 3W power amp in the truck will help it get range. It
doesn't have AMPS in it, of course, so time will tell how it works on the
power amp in the boonies where I work. Alltel's rural CDMA is much
better than it used to be, here. I can also dial 611 on the big,
honkin' Alltel bagphone that's not registered and bullshit my way into a
call on AMPS if the E815 fails to make the trip on CDMA. I've done it
before, while reporting the dead spots to the 611 operator who will
answer the AMPS unregistered call.

I'm watching Fox News on MobilTV with Alltel Axcess TV I just bought
today. Axcess TV is $10/month but that sucks up airtime. Unlimited data
to feed Axcess TV is another $10/month, so I have 25 channels of color TV
for $20/month. Alltel doesn't force you to buy internet to get TV or XM.
The TV works really nice if there's 1-2 bars of signal....(c;

Larry
--
Message for Comcrap Internet Customers:
http://tinyurl.com/3ayl9c
Unlimited Service my XXX.....(d^:)

baumgrenze

2007-03-25, 10:33 pm

Bob,

Thanks for staying 'on topic.' Perhaps the rest of this thread does
deal with my question, but how it does so is unclear to me.

baumgrenze

> try 2. you might see something like a bunch of numbers or abbreviations and
> numbers.
> Stay away from numbers5 thru 7. And remember I am not responsible for what
> happens to your phone. If your phone locks up, pulling the battery should
> put it back to normal.
>
> --
> --
> Coffee worth staying up for - NY Timeswww.moondoggiecoffee.com

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