*PING* - Jud Hardcastle

PING - Jud Hardcastle

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

Bob Walker - 26 Oct 2005 20:30 GMT

Like you, I have been a strong proponent of GAIT phones. I have often lost
the GSM network on my T62u phone, especially as I drive south and west from
Dallas. It often switches to TDMA, and on occasions to AMPS.

The reason for my note is that I have recently been using my wife's V551 and
have found that I have no trouble with GSM in areas where my T62u was
marginal.

I wonder whether you have tried a GSM-only phone where you travel. In a few
days I will be in the Florida boonies near Lake Okeechobee and plan to take
the T62u, but I'm interested in finding out whether the V551 is adequate.
I'll let you know if you're interested.

Bob Walker

Reply to this Message

Jud Hardcastle - 27 Oct 2005 05:56 GMT

> The reason for my note is that I have recently been using my wife's V551 and
> have found that I have no trouble with GSM in areas where my T62u was
[quoted text clipped - 4 lines]
> the T62u, but I'm interested in finding out whether the V551 is adequate.
> I'll let you know if you're interested.

Not yet. We have two 6340i's and so far have avoided getting a GSM-only
model. I don't think it would make a difference though. The Nokias
weren't marginal in those non-GSM areas--field test showed no GSM
available at all. Not even with an external antenna.

Pretty soon I may not have a choice though--one of the 6340i's is an
older software version and it's been doing strange things. Apparently
Cingular has been taking TDMA down in Dallas for a day or two at a
time--field test shows AMPS only on the 21xx screens. (Right now in
fact--Wed 11pm--ACCH only/DCCH not active). Only sometimes when they do
that this phone powers off. I power it back on--it powers off--then
on--then off etc. Have to do that a half dozen times before it will
stay on. Probably getting a fatal error in the registration logic. I'm
kinda expecting it to do that one time and not come back at all. The
6340i with the newer software doesn't do that--and I suspect I waited
too long to send the older unit in for flashing.

My old pda is having problems also so I was trying to wait until the
"right" combined pocketpc/phone that had the features I want (including
external antenna socket) and no more (no camera would be preferred)
comes out. Hope both hold together until then otherwise I may have to
either get a cheapie GSM model or another 6340i off ebay *if* Cingular
will activate it as a replacement (the TDMA/AMPS half of course since
the SIM will just transfer).

Let us know how the T62U versus V551 comparison works out.

Signature

Jud
Dallas TX USA

Reply to this Message

Bob Walker - 13 Nov 2005 03:33 GMT

>> The reason for my note is that I have recently been using my wife's V551
>> and
[quoted text clipped - 34 lines]
>
> Let us know how the T62U versus V551 comparison works out.

Jud,

While I didn't have time to do extensive comparisons on my trip, the limited
testing I did was very interesting. I had excellent GSM/GPRS coverage with
the V551 all over Central Florida, including Sebring, Lake Placid, Zolfo
Springs, Bradenton, Mt. Dora, Eustice and many other small towns and rural
areas.

When I arrived in Sebring the battery on my V551 was low so I moved the SIM
to my T62u. It started in TDMA mode and never found a GSM signal. When I
switched to the V551 the next morning, it had a strong GSM signal. This
indicates to me that at least in that area, the performance of the GAIT
phone was deceiving. I never found a need to use the T62u other than that
time.

It might be time for you to borrow a good GSM-only phone and try it in the
rural areas you visit. The coverage may be better than you think. Let us
know what you find.

Bob

Reply to this Message

John Navas - 13 Nov 2005 14:39 GMT

>> Let us know how the T62U versus V551 comparison works out.

>While I didn't have time to do extensive comparisons on my trip, the limited
>testing I did was very interesting. I had excellent GSM/GPRS coverage with
[quoted text clipped - 7 lines]
>indicates to me that at least in that area, the performance of the GAIT
>phone was deceiving. ...

That's not surprising. It's a common misconception that a GAIT phone will
automatically pick the best signal, GSM or TDMA, home or roaming. It won't.

While GAIT (both TDMA/Analog technology and GSM technology in the same phone)
will give the best possible *coverage*, actual performance is governed by the
programming of the SIM, which won't necessarily give you the best possible
*signal*. My prior posts have explained how and why this matters:

------------------------------------------------------------------------------

Which network the phone will select depends on how the phone is
programmed (on the SIM) by the carrier. There are four different modes
of GAIT operation:

* GSM Native Mode: This is where the mobile is homed to a GSM
network and is operating on a GSM network. In this mode, the mobile
is able to perform standard GSM type functions including SMS and Data
services (circuit switched at 9600 or 14400 bps and packet switched
service if it is offered).

* ANSI-136 Native Mode: This is where the mobile is homed to an
ANSI-136 network and is operating on an ANSI-136 network. In this
mode, the mobile is able to perform standard ANSI-136 functions
including text messaging using GHOST SMS and Data services (circuit
switched at 9600 bps).

* GSM Foreign Mode: This is where the mobile is homed to an
ANSI-136 network but is operating on a GSM network. At this time, the
GSM portion of the phone is operational and the network's
Interworking and Interoperability Function (IIF) handles the call
delivery and SMS routing from the ANSI-136 network to the serving GSM
network.

* ANSI-136 Foreign Mode: This is where a GSM native subscriber is
accessing an ANSI-136 network. Again, routing of calls and SMS is
handled by the network's Interworking and Interoperability Function.

In short, a GAIT phone will be "homed" to either GSM or ANSI-136 (TDMA).
Network selection will be based on standard mechanisms in both
technologies.

Suppose that the GAIT phone scans for service and determines that there
are two networks available for selection, an ANSI-136 Neutral system and
a GSM Neutral system. If the PPI (Protocol Priority Indicator) is set to
ANSI-136 Preferred, then the mobile selects the ANSI-136 Neutral system.
Conversely, if the PPI is set to GSM Preferred, then the mobile selects
the GSM Neutral system.

Suppose that the GAIT phone scans for service and determines that there
are two network available for selection, an ANSI-136 Group A (Home)
system and a GSM Group B (Preferred) system. The mobile selects the
ANSI-136 system even if the signal is better on the GSM system.

Network selection is a function of preferences configured by the
carrier, not signal strength. It doesn't matter that the signal might
be better on the other technology.

<<>>

Signature

Best regards, HELP FOR CINGULAR GSM & SONY ERICSSON PHONES:
John Navas <http://navasgrp.home.att.net/#Cingular>

Reply to this Message

Jud Hardcastle - 13 Nov 2005 19:17 GMT

> >When I arrived in Sebring the battery on my V551 was low so I moved the SIM
> >to my T62u. It started in TDMA mode and never found a GSM signal. When I
[quoted text clipped - 3 lines]
> carrier, not signal strength. It doesn't matter that the signal might
> be better on the other technology.

Sounds like Bob's is homed on TDMA. Mine appears to be homed on GSM
since it always holds onto a GSM signal even if a superstrong TDMA
signal is present or will switch back after a few minutes if a weak GSM
signal reappears where there wasn't one--I've never seen it pick a TDMA
signal over a GSM one since DFW came up on GSM. I imagine they rehomed
the GAIT users then (the ones on a real GAIT account that is).

However, Bob said "never found a GSM signal" even though there was one.
That sounds more like a case of not seeing either the orange or blue
side. I don't "think" I'm having that problem since this software
version says "AT&T Wireless" when it uses ATT rather than "Cingular" or
"Cingular Extend"--it's clearly seeing it and working fine on it. I
don't recall if Bob is actually ON a GAIT plan or not--the programming
may be totally different for GSM users with GAIT option.

Signature

Jud
Dallas TX USA

Reply to this Message

Bob Walker - 14 Nov 2005 16:53 GMT

> However, Bob said "never found a GSM signal" even though there was one.
> That sounds more like a case of not seeing either the orange or blue
[quoted text clipped - 3 lines]
> don't recall if Bob is actually ON a GAIT plan or not--the programming
> may be totally different for GSM users with GAIT option.

It probably would have been more correct if I had said it never "used" a GSM
network. I'm not aware of a way to identify the available networks with
that phone, but I do have the display set to show the type network it is
using (G, T, or A).

When I bought the GAIT phone I was put on a GAIT plan. When I upgraded to
the V551 in January '05 I told Cingular I wanted to continue using the T62u
periodically so they activated "GAIT calling area" and "GAIT for GSM" on my
account.

At one point I was having a problem with the phone switching from GSM to
TDMA and then not switching back when GSM became available again. Someone
in the North Texas sales office made an adjustment to correct that, which I
assume means that I am "homed" on GSM.

I know that each area stands alone, but the experience I had in relatively
unpopulated locations in Florida was very surprising to me. I would think
rural Texas might be similar.

Bob

Reply to this Message

Jud Hardcastle - 15 Nov 2005 15:57 GMT

> I know that each area stands alone, but the experience I had in relatively
> unpopulated locations in Florida was very surprising to me. I would think
> rural Texas might be similar.

Could be--I don't have a pure GSM phone so no way to test in areas where
the 6340 says no GSM. I'm looking at the combined pda/phones but still
waiting for one that I like--maybe early next year. By then hopefully
it'll be a moot point.

Signature

Jud
Dallas TX USA

Reply to this Message