MiFi purchase and contract options?

On Sat, 03 Jul 2010 21:35:50 -0700, in
<[email protected]>, Jeff Liebermann
<[email protected]> wrote:

>Yep. I'm not surprised. AT&T got severely embarassed when Verizon
>published the real map of their 3G network. Since they can't build
>the network fast enough, might as well remove the tools needed to
>attach numbers to the coverage.
>
>Apple: You don't need to know.
>AT&T: We don't want you to know.

Verizon: You think you know but the map's not accurate, in addition to
being misleading about the difference between 3G and total coverage.
(That's based on real experience comparing the map to actual coverage.)

>Yep. Worse, when the system is really busy, like during rush hour,
>VZW will drop calls that have been running for over 10-15 minutes to
>make room for new callers. I suspect the other service providers are
>doing something similar. It's really difficult to tell what caused a
>call to drop from the handset end.

On what do you base that? My friend at Verizon claims the real issue is
cell "breathing".

--
Best regards,
John

"Never attribute to malice that which can be
adequately explained by stupidity." [Hanlon's razor]

---

› See More: MiFi purchase and contract options?

On Sat, 03 Jul 2010 22:26:25 -0700, in
<[email protected]>, Jeff Liebermann
<[email protected]> wrote:

>On Sat, 03 Jul 2010 21:42:45 -0700, nospam <[email protected]>
>wrote:
>
>>> Yep. Worse, when the system is really busy, like during rush hour,
>>> VZW will drop calls that have been running for over 10-15 minutes to
>>> make room for new callers. I suspect the other service providers are
>>> doing something similar.
>>
>>are you referring to cdma cell shrinkage? that is *really* hard to
>>explain to people.
>
>No, not CDMA cell breathing, although that could contribute to
>disconnects.
><http://www.macltd.com/datafile_downloads/MAC%20Ltd%20-%20Cell%20Breathing.pdf>
>It's just an increase in the noise floor with CDMA causing a decrease
>in usable range.
>
>What's happening is the Verizon got too many complaints about busy
>signals and incoming calls going directly to voice mail. Since the
>cell capacity could not be easily or economical increased without
>additional frequencies, Verizon opted to kick off the ratchet jaw
>yackers and allow new calls to have priority, when the system gets
>busy. That eliminated most of the busy signals. Meanwhile, those
>getting kicked off never suspected that the call was intentionally
>dropped, and probably guessed that they had driven through a weak
>signal area, or that a handoff had failed. It's possible that VZW is
>also dropping weak (low SNR) calls when the system gets busy, on the
>assumption that they're going to drop out anyway.

Again, on what do you base that? My friend at Verizon claims the only
real issue is cell "breathing".

--
Best regards,
John

"Never attribute to malice that which can be
adequately explained by stupidity." [Hanlon's razor]

On Sat, 03 Jul 2010 22:34:15 -0600, in
<[email protected]>, Todd Allcock
<[email protected]> wrote:

>At 03 Jul 2010 16:38:49 -0700 nospam wrote:
>> In article <[email protected]>, Todd Allcock
>> <[email protected]> wrote:
>>
>> > I like that meter. My HTC-built Sony X1 (great PDA, terrible phone)
>> > switches from 5 bars to 4 at -90 dbm. That's a meter designed to "hide"
>> > a lousy phone! Consequently, I get very little warning before losing
>> > signal entirely. The bars drop from 5 to 0 rather quickly in weak areas.
>>
>> they're deceiving you. time for a lawsuit.
>
>Thankfully, HTC includes a Field Test app with their devices. I'm only a
>few taps away from knowing what the score is, regardless of what the bars
>say.

Yep -- HTC makes great phones, which is why Apple has decided it has to
compete in court instead of just in the market. On my HTC phone: Menu >
Settings > About phone > Status > Signal strength (currently -89 dBm 12
asu).

--
Best regards,
John

If the iPhone and iPad are really so impressive,
then why do iFans keep making excuses for them?

Jeff Liebermann <[email protected]> wrote in
news:[email protected]:

> Matching
> a wide range of frequencies is not.
>

http://en.wikipedia.org/wiki/Log-periodic_antenna

http://www.radio-electronics.com/inf...g_periodic.php

http://www.tpub.com/content/et/14092/css/14092_35.htm

http://www.ramseyelectronics.com/dow...nuals/DA25.pdf

Here's your slot iPhone 4 antenna...nothing new...
http://archive.electronicdesign.com/.../figure_01.gif

http://ceta.mit.edu/PIER/pier86/10.08090701.pdf
very broadband antennas can be made for microwave frequencies from PC board
material.

http://www.sumobrain.com/patents/wip...band-tem-horn-
antenna/WO1997012252A1.pdf

Matching a wide range of frequencies isn't much of a challenge in 2010.

Placing the antenna where it will have a reasonable chance of radiating
into space is becoming more and more of a political problem as the greenies
take over the political system.



--
Global Warming and Creationism are to science what storks are to
obstetrics...

Larry

Jeff Liebermann <[email protected]> wrote in
news:[email protected]:

> Yep. Worse, when the system is really busy, like during rush hour,
> VZW will drop calls that have been running for over 10-15 minutes to
> make room for new callers. I suspect the other service providers are
> doing something similar. It's really difficult to tell what caused a
> call to drop from the handset end.
>
>

Jeff, did you see the news where the Feds are going to give up another 500
Mhz for more wireless bandwidth?

It was on Google News midweek.


--
Global Warming and Creationism are to science what storks are to
obstetrics...

Larry

nospam <[email protected]> wrote in news:030720102142454132%
[email protected]d:

> right, and people are blaming the iphone antenna, without having ruled
> out other causes.
>
>

Ruling out other causes is very easy. Just pick up the cheapest free phone
ATT sells and dial out a call right next to iPhone 4. Does the call work?
Yes? Not the infrastructure or traffic's fault. That points it quickly at
the real cause of failures.....iPhone 4's defective antenna system.

If Apple's gonna be in the radio business, they need to hire some radio
engineers....


--
Global Warming and Creationism are to science what storks are to
obstetrics...

Larry

On Sun, 04 Jul 2010 15:12:12 +0000, in
<[email protected]>, Larry <[email protected]>
wrote:

>nospam <[email protected]> wrote in news:030720102142454132%
>[email protected]:
>
>> right, and people are blaming the iphone antenna, without having ruled
>> out other causes.
>
>Ruling out other causes is very easy. Just pick up the cheapest free phone
>ATT sells and dial out a call right next to iPhone 4. Does the call work?
>Yes? Not the infrastructure or traffic's fault. That points it quickly at
>the real cause of failures.....iPhone 4's defective antenna system.

Yep.

>If Apple's gonna be in the radio business, they need to hire some radio
>engineers....

They are trying to do just that.

--
Best regards,
John

If the iPhone and iPad are really so impressive,
then why do iFans keep making excuses for them?

"John Navas" <[email protected]> wrote in message
news:[email protected]...
> On Sun, 04 Jul 2010 15:12:12 +0000, in
> <[email protected]>, Larry <[email protected]>
> wrote:
>
>>nospam <[email protected]> wrote in news:030720102142454132%
>>[email protected]:
>>
>>> right, and people are blaming the iphone antenna, without having ruled
>>> out other causes.
>>
>>Ruling out other causes is very easy. Just pick up the cheapest free
>>phone
>>ATT sells and dial out a call right next to iPhone 4. Does the call work?
>>Yes? Not the infrastructure or traffic's fault. That points it quickly
>>at
>>the real cause of failures.....iPhone 4's defective antenna system.
>
> Yep.
>
>>If Apple's gonna be in the radio business, they need to hire some radio
>>engineers....
>
> They are trying to do just that.
>

They've been at the game for years and so far have not been able to do so.
(MacBook etc has very poor performance wrt wifi antenna)

In article <[email protected]>, John Navas
<[email protected]> wrote:

> Yep -- HTC makes great phones, which is why Apple has decided it has to
> compete in court instead of just in the market.

nonsense. how conveniently you forget that htc infringed not only on
apple intellectual property, but microsoft too.

In article <[email protected]>, Larry
<[email protected]> wrote:

> Ruling out other causes is very easy. Just pick up the cheapest free phone
> ATT sells and dial out a call right next to iPhone 4. Does the call work?
> Yes? Not the infrastructure or traffic's fault. That points it quickly at
> the real cause of failures.....iPhone 4's defective antenna system.

that's not a controlled test in the least. there are way too many
variables to be able to say it's *only* the antenna.

> If Apple's gonna be in the radio business, they need to hire some radio
> engineers....

they have plenty.

On Sun, 04 Jul 2010 15:07:50 +0000, Larry <[email protected]> wrote:

>Jeff Liebermann <[email protected]> wrote in
>news:[email protected]:
>
>> Matching
>> a wide range of frequencies is not.

Hint: I do some antenna design in my spare time:
<http://802.11junk.com/jeffl/antennas/>

>http://en.wikipedia.org/wiki/Log-periodic_antenna
>http://www.radio-electronics.com/inf...g_periodic.php

A log periodic antenna will not fit inside an iPhone. It's also
rather directional, which is not what's needed in a cell phone. With
small antennas, the efficiency is what usually goes down the drain
first. Directionality goes next, as small antennas like to radiate in
a spherical pattern, which mangles the SAR test. Most cellular
antennas are loaded monopoles, PIFA, fractal, or just plain squashed
into a pretzel. If I'm lazy, I just input the target specs into the
modeling program, fire off the optimizer, and leave for a short
vacation. When I return, I have a weird looking, best effort antenna,
which usually works amazingly well.

Incidentally, I have built LPDA antennas on e=10 ceramic substrates,
which will reduce the size by about a factor of 4. However, for
800-1900MHz, it's still to big for inside a cell phone.

>http://www.tpub.com/content/et/14092/css/14092_35.htm

Close. That's a conical dipole. Inverting the cones results in a
bi-conical, which is an excellent broadband dipole. However, it has
the same problem as the LPDA. It won't fit.

>http://www.ramseyelectronics.com/dow...nuals/DA25.pdf

That's a discone. It's half a bi-conical, with a capacitive hat. It's
one of the worst antennas ever sold, were it not for the advantage of
having a huge bandwidth. For a base station, if you don't mind having
all of your RF going well above the horizon, it's fine. That's why
you see it at airports.

>Here's your slot iPhone 4 antenna...nothing new...
>http://archive.electronicdesign.com/.../figure_01.gif

Hmmm.... 5 different antennas. Here's some exploded views of the
iPhone that might help you identify which of the 4 antennas is in the
iPhone 4:
<http://www.ifixit.com/Teardown/iPhone-4-Teardown/3130/>
Hint: The stainless frame is not a patch antenna because it's no
suspended above a ground plane. It's also not a loop because it's
broken into 2 seperate antennas (one for BT and Wi-Fi, the other for
cellular). There's no meandering line or slot.

However, the iPhone 4 antenna might be a PIFA antenna, which is the
"inverted F" in the picture. I can't tell from the photos or the FCC
page. When I get my hands on an iPhone, or better photos, I can make
a determination. I wouldn't be surprised if the frame antenna is just
a piece of wire with a messy matching circuit.

>http://ceta.mit.edu/PIER/pier86/10.08090701.pdf
>very broadband antennas can be made for microwave frequencies from PC board
>material.

Yep. UWB antennas are difficult but possible. However interesting,
the iPhone 4 is not a UWB device and only needs to operate on 800,
900, 1800, and 1900 MHz.

>http://www.sumobrain.com/patents/wip...97012252A1.pdf

That's a horn antenna. I'm trying to visualize how one would use a
horn antenna with a cell phone. Certainly they're broadband, but are
more suitable for illuminating a dish antenna, than cramming into a
cell phone. Same problem as the others... too big and too
directional.

>Matching a wide range of frequencies isn't much of a challenge in 2010.

It is difficult in a cell phone. If you don't care about size, shape,
directionality, SAR, gain, and price, it's easy.

Hint... do some searching in the IEEE Antennas and Propagation
Journal:
<http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=74>
Type "cellular antenna" into the search box near the top of the page.
You won't get the contents, but the abstract should be sufficient for
this exercise. 3800 articles.

>Placing the antenna where it will have a reasonable chance of radiating
>into space is becoming more and more of a political problem as the greenies
>take over the political system.

That's true for cell sites. I'm somewhat involved locally in the
process. However, I don't think that politics had anything to do with
the design of the iPhone 4 antenna.

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

On Sun, 04 Jul 2010 07:30:43 -0700, John Navas
<[email protected]> wrote:

>On Sat, 03 Jul 2010 21:35:50 -0700, in
><[email protected]>, Jeff Liebermann
><[email protected]> wrote:
>
>>Yep. I'm not surprised. AT&T got severely embarassed when Verizon
>>published the real map of their 3G network. Since they can't build
>>the network fast enough, might as well remove the tools needed to
>>attach numbers to the coverage.
>>
>>Apple: You don't need to know.
>>AT&T: We don't want you to know.
>
>Verizon: You think you know but the map's not accurate, in addition to
>being misleading about the difference between 3G and total coverage.
>(That's based on real experience comparing the map to actual coverage.)

No kidding. Since the composite AT&T map is now 9 months old:
<http://802.11junk.com/jeffl/crud/ATT3Gmap.jpg> (2.6MB)
I decided it was time to throw together an updated version. But
first, I decided to see what it claimed about local coverage. I know
where the local AT&T sites are located, and which way the panels are
aimed, so that's easy for me. I was aghast. Not only does it claim
coverage where I know none exists, but the islands of strong signals,
which should correspond to the cell sites, is all wrong. At first I
thought it might be a mapping offset (like conversion from NAD27 to
WGS84), but it's almost random. I don't know how it's generated, but
it's wrong.

I also noted that AT&T changed the colors on their "data" map, so that
3G is dark blue, while EDGE/GPRS, and roaming are slightly lighter
blue with some black cross hatching. It's very difficult for me to
separate these due to the (intentional) choice of indistinguishable
colors.
<http://www.wireless.att.com/coverageviewer/>

Incidentally, I blundered across this site, which has links and screen
grabs of many cellular maps:
<http://www.cellularmaps.com>

If AT&T is bad, Verizon is the same, only in a different way.
<http://www.verizonwireless.com/b2c/CoverageLocatorController?requesttype=NEWREQUEST>
Although Verizon map color differentiation is much improved over AT&T,
you can't see any gradations unless you zoom down to the city level.
There's no way to get a regional picture of coverage. From the region
view, it looks like Verizon covers the entire area, which is at least
locally, is grossly incorrect. Zooming in shows little detail. There
are only 3 grades of service (full, marginal, none), which is useless.

Extra credit for Verizon still showing analog coverage on their map.

AT&T: We know, but we'll make it difficult for you to tell.
Verizon: We know, but we're not telling.

>>Yep. Worse, when the system is really busy, like during rush hour,
>>VZW will drop calls that have been running for over 10-15 minutes to
>>make room for new callers. I suspect the other service providers are
>>doing something similar. It's really difficult to tell what caused a
>>call to drop from the handset end.
>
>On what do you base that? My friend at Verizon claims the real issue is
>cell "breathing".

Personal experience, and some info from Verizon dealers, employees and
contractors. I don't want to reveal my sources. Note that dropped
calls is their number one technical complaint (as of about 2 years
ago).

To be fair, I don't know for sure if they're really intentionally
dropping calls. I do know that I can't maintain a call for more than
about 10 minutes at 5PM no matter how strong a signal. I was
literally under the VZW cell site antenna when I was dropped. At
other times of the day, that doesn't happen. I don't make too many
calls at 5PM over 10 minutes, so my experience is limited. However, I
deal with other local users that have had similar experiences. I
really doubt that Verizon or any other carrier will admit that they're
doing this but I do consider it a good way to free up channels when
the system gets busy.

Cell breathing could easily cause the same effect. As the number of
users increases, the base line noise level goes up. However, the way
the cell site defends itself is to refuse to accept new connections
until the noise level decreases to tolerable levels.
<http://www.macltd.com/datafile_downloads/MAC%20Ltd%20-%20Cell%20Breathing.pdf>
See graph on Page 5. In theory, by blocking new calls, the noise
level will never exceed some pre-defined level. Were sites located
with some overlap, and the adjacent site has available channels,
breathing should not create a dead zone.

More:
<http://reviews.ebay.com/Cell-Phone-Reception-Why-Does-My-Phone-Drop-Calls_W0QQugidZ10000000001602525>
"Again, its rarely the cell phone that is the cause of dropped calls,
it is the wireless network including its towers and switches."

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

On Sun, 04 Jul 2010 15:09:52 +0000, Larry <[email protected]> wrote:

>Jeff Liebermann <[email protected]> wrote in
>news:[email protected]:
>
>> Yep. Worse, when the system is really busy, like during rush hour,
>> VZW will drop calls that have been running for over 10-15 minutes to
>> make room for new callers. I suspect the other service providers are
>> doing something similar. It's really difficult to tell what caused a
>> call to drop from the handset end.

>Jeff, did you see the news where the Feds are going to give up another 500
>Mhz for more wireless bandwidth?
>
>It was on Google News midweek.

No, I didn't. I couldn't find anything of the sort with various
searches. Got a link? All I could find is that Obama is "backing"
the release, whatever that means:
<http://www.telecoms.com/21309/obama-plans-to-free-up-500mhz-of-spectrum/>
Obama said the government would collaborate with the Federal
Communications Commission (FCC) to make available a total of
500MHz of federal and non-federal spectrum over the next ten
years, suitable for both mobile and fixed wireless broadband
use, to be licensed and made available for shared access by
commercial and Government users.

Note the "federal and non-federal spectrum". That's about as vague as
any politician could make it. I would guess that includes all
spectrum.

Never mind that any change in allocation will require ITC/WRC approval
before it can be reallocated. At best, maybe 5 years for minor
changes.

The last and only release of federal spectrum was the shared release
of 3650-3700Mhz in 2007, a paltry 50MHz.
<http://wireless.fcc.gov/services/index.htm?job=service_home&id=3650_3700>
Unfortunately, it's useless within 50 miles of major metro areas
thanks to the need to protect Sprint satellite uplinks. Where the FCC
is going to find 500MHz of spectrum of uncontested spectrum needed for
mobile and fixed wireless (actually for auction), is anyone's guess.


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

In article
<[email protected]>,
"Elmo P. Shagnasty" <[email protected]> wrote:

> In article <[email protected]>,
> David <[email protected]> wrote:
>
> > Strange why people are just complaining about the new phone, my 3GS has
> > always dropped signal strength remarkably if I hold it with my hand
> > around the top half/
> >
> > The difference is that it will go from 3bars to no bars depending on how
> > I hold it, and that is with a case on it
>
> I bet you haven't actually logged and tracked your experiences.
>
> Your phone will go from 3 bars to no bars sitting on a table, not
> moving, with NO ONE touching it. Case or no case.
>
> It has nothing to do with you and how you hold the phone, and everything
> to do with....AT&T.

Gee whiz I doubt that. Considering I am thousands of KM away from them
living in the land of Oz I think it more likely it is to do with the
design of the phone.

And with laying down it doesn't change

David - who wonders where people get such strange ideas from...

In article <[email protected]>,
John Navas <[email protected]> wrote:

> >
> >Strange why people are just complaining about the new phone, my 3GS has
> >always dropped signal strength remarkably if I hold it with my hand
> >around the top half/
> >
> >The difference is that it will go from 3bars to no bars depending on how
> >I hold it, and that is with a case on it
>
> It can be normal for signals bars to fluctuate even when not touching
> the phone or moving. Some phones, for example, will switch back and
> forth between the signal strength of home and foreign networks. This
> can be very frustrating when a foreign network has a good signal and the
> home network has a poor signal, but the phone is only allowed on the
> home network.

John, I live in a rural area where there is only one provider, Telstra.
So it is the phone

David