Colin P. Fahey

Motorola T720 GSM PHONE SETTINGS FOR AT&T

Introduction

This section is really just for my personal reference.  The information
provided here certainly only applies to AT&T customers with the Motorola T720
GSM phone, and may only apply to customers in the Los Angeles, California area.
In fact, I'll go so far as to make the outrageous disclaimer that this
information may only apply to me...and only for today.

Web Session Settings


Main Screen
  Main Menu
    More... (Not necessary if list view instead of icon view)
      Web Sessions
        mMode (NOTE: Do [New Entry] if no nMode entry)
          (*** Hit menu key, not LAUNCH! ***)
            Edit
              Name:           mMode
              Homepage:       http://home
              WAP IP 1:       10.250.250.250
              WAP Port 1:     9203
              WAP IP 2:       10.250.250.250
              WAP Port 2:     9203
              Timeout:        2 minutes
              CSD No. 1:      ____________ (blank)
              User Name 1:    ____________ (blank)
              Password 1:     ____________ (blank)
              Speed (Bps) 1:  9600
              Line Type 1:    ISDN
              CSD No. 2:      ____________ (blank)
              User Name 2:    ____________ (blank)
              Password 2:     ____________ (blank)
              Speed (Bps) 2:  9600
              Line Type 2:    Modem
              GPRS APN:       proxy
              User Name:      ____________ (blank)
              Password:       ____________ (blank)



Also, there is a DNS setting for Java apps:


Main Menu
  Settings
    Java Tools
      DNS IP:  10.250.1.10


NOTES REGARDING THESE SETTINGS:

[a] Doing a "master reset" will set the WAP Port numbers to "9201", so these
    must be changed to "9203".

[b] The secondary WAP IP and Port is set to the same IP and port as the primary
    WAP settings.  I was able to use "mMode" (i.e., go to URL's) with a totally
    blank secondary WAP setting, but I had "Line Type 1: Modem" at that time.
    I don't know if setting it to "ISDN" makes it more likely that the
    secondary WAP settings will be used.

[c] A "master reset" makes the "Timeout:" field "15 minutes".  Change to
    "2 minutes".

[d] The "Name:", "Homepage:", and "GPRS APN:" fields all involve typing in
    letters and symbols manually.

[e] The blank fields really are meant to be left blank.

GSM TECHNOLOGY, RECEPTION ISSUES

Physics of 1900MHz (1.9Ghz) GSM Reception

I'm not positive, but I hear that AT&T's GSM network uses 1900MHz exclusively.
Other technologies and carriers use significantly lower frequencies (longer
wavelengths), around 800 MHz, for example.

In general, low frequency electromagnetic waves are able to penetrate objects
and bend around objects.  Thus, you can hear AM radio broadcasts (~1 MHz) in
underground tunnels and around buildings and mountains.  Higher frequency
broadcasts, like FM radio (88-108MHz) penetrate and bend less, so reception may
be poor deep inside buildings or behind large obstructions.  Similarly, 800 MHz
signals can penetrate and bend more than 1900 MHz signals.  If we increase the
frequency much more, to Infrared (~6000 GHz!) or visible light (~600,000 GHz!),
it becomes obvious that even penetration through cardboard is very difficult,
and bending around obstacles is insignificant (hence very distinct shadows).
The actual curve of penetration ability versus photon frequency for a given
material (brick, metal, water, etc) generally decreases with increasing
frequency but eventually increases for extremely high frequencies (X-Rays,
Gamma Rays), and the curve can be quite complicated, since there are many ways
that a photon of a given frequency can be absorbed by a given material.

Thus, 1900 MHz GSM signals penetrate less and bend less than the lower-
frequency (e.g., about 800 MHz) signals that happen to be used in conjunction
with older technologies and with other other carriers.

Anyhow, the subjective result of this is that GSM phones have bad reception
indoors and in places where there is a significant obstruction between the cell
tower and the phone.  I believe that the AT&T TDMA phones use a much lower
frequency (like 850 MHz), and thus can have better reception under conditions
that would lead to poor reception for 1900 MHz GSM phones.


Deployment of 1900MHz (1.9Ghz) GSM by AT&T

Another practical consideration is the fact that GSM is a new technology, and
although AT&T is building more GSM towers all the time, the current coverage is
limited to heavily-populated areas.

Some people have estimated that GSM coverage will expand to rural areas and
will generally be complete by the year 2006.

Even cell tower density in heavily-populated areas may need to be increased, to
make the distance to any given cell phone less, to compensate for poor 1900 MHz
signal penetration ability.


Growing Pains of mMode

When I first bought the AT&T version of the Motorola T720, I couldn't access
the Internet for many days, which was frustrating and kind of discouraging.
Then, at random, a friend asked to borrow the battery from my phone (to do a
download to his T720 after his battery was drained).  When he returned the
battery and I turned my phone back on, BOOM, I had network access!

Apparently, power-cycling the phone daily is a commonly recommended practice,
even by other carriers (e.g., T-Mobile).  Why can't a high-tech phone have some
other strategy to achieve whatever must be done?  Who knows!

At the time I am writing this paragraph, I am in the middle of an mMode
"blackout" that has lasted over two days and apparently affects Los Angeles
County and Orange County.  Customer service representatives had very little
information on the specifics of this outage, and no estimate of when it would
be resolved.  On the AT&T web site discussion forums I learned that there was
a similar outage in central California right before our outage in Southern
California.  Maybe it's just scheduled system upgrades.  I just wish the phone
wasn't so vague about what was going on:

  "Connection unsuccessful. Try again later."

For a while I assumed "later" meant "5 seconds from now", or maybe "5 minutes"
from now.  But not "5 days" from now!

Universal Rant About Error Messages!

In general, I think there is a worldwide crisis of vague error messages.
Microsoft Windows has its share of completely vague messages.  But the cell
phone is the king of vague error messages!  The only way I could figure out
what any given cell phone error message actually indicated was to finally
overcome the problem by trial and error and isolate what must have been the
cause of the problem.  Thus I can make the absolutely insane correspondance
between "406: Not Acceptable" and servers not setting the proper MIME type for
the downloaded data.  I know that some error messages (including this example)
actually properly describe the immediate direct cause of the malfunction, but I
wish there was some extra speculative comments along with the error message,
like: "Server did not set MIME type for data?" or "Unknown MIME type" or
"Unsupported MIME type".

I also wish messages proposing solutions were less vague.  "Try again later."
is really bad!  How about: "Current Unavailability Estimate: 4 days"?  This
estimate would be updated each time you attempted the operation.

CONTACT INFORMATION
Colin P. Fahey
cpfahey@earthlink.net
http://www.colinfahey.com