question about att, cingular sharing gsm

I am in a small town in Wisconsin. I just purchased a Sony T616 phone
with ATT GSM service. As ATT just turned on GSM coverage in my area 2
months ago, the service is not stable and sometimes my phone switch to
use cingular service which ATT will charge me for roaming.

My phone screen will show what service is in use before I call or
receive call. My only worry is: if I am talking on the phone and
stepping from ATT coverage into Cingular coverage, will it switch
service automatically or will the singal simply dies??

Of course I am hoping the signal dies (instead of switching to
cingular) while the phone is in use...

Thanks,
Susan

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› See More: question about att, cingular sharing gsm

Susan Lam wrote:
> I am in a small town in Wisconsin. I just purchased a Sony T616 phone
> with ATT GSM service. As ATT just turned on GSM coverage in my area 2
> months ago, the service is not stable and sometimes my phone switch to
> use cingular service which ATT will charge me for roaming.
>
> My phone screen will show what service is in use before I call or
> receive call. My only worry is: if I am talking on the phone and
> stepping from ATT coverage into Cingular coverage, will it switch
> service automatically or will the singal simply dies??
>
> Of course I am hoping the signal dies (instead of switching to
> cingular) while the phone is in use...
>
> Thanks,
> Susan


Susan, as things have been explained to me, the short answer is no, the
call shouldn't drop. Roaming partners become partners when they have
"hand off trunks" set up between the two. Each carrier's network is
"neighbour aware", so, if a call appears to transition from one to the
other, a HO trunk is used to handoff the call, hopefully preventing it
from being dropped. I suppose if there are no HO trunks available at
that particular time, eventually it WILL drop because there's nothing
else the network can do except watch you fade off the coverage edge. Of
course, this whole scenario depends on whether your carrier will LET you
roam onto that neighbour's network - depending on what plan you have,
and whether the control functions in your GSM handset has been updated
appropriately. When GSM handsets are turned on (within their home
network area), the handset and the network collectively determine if
your handset needs updating, and does so if it stays online for a few
moments. If your GSM handset is turned on outside your home network
coverage, updates aren't possible, and the longer it stays away from
home, the older the programming gets and eventually may cause problems
when it comes to determining what/who your roaming choices could be.

At least that's the way I understand it. Maybe someone else will jump
in here an tell us how it really works.

--
jer email reply - I am not a 'ten' ICQ = 35253273
"All that we do is touched with ocean, yet we remain on the shore of
what we know." -- Richard Wilbur

Susan Lam wrote:
> I am in a small town in Wisconsin. I just purchased a Sony T616 phone
> with ATT GSM service. As ATT just turned on GSM coverage in my area 2
> months ago, the service is not stable and sometimes my phone switch to
> use cingular service which ATT will charge me for roaming.
>
> My phone screen will show what service is in use before I call or
> receive call. My only worry is: if I am talking on the phone and
> stepping from ATT coverage into Cingular coverage, will it switch
> service automatically or will the singal simply dies??
>
> Of course I am hoping the signal dies (instead of switching to
> cingular) while the phone is in use...
>
> Thanks,
> Susan

I am on the Cingular Preferred Nation, I currently have a TDMA/AMPS
handset, and I am upgrading to a GAIT handset this month. It has
happened many times I have switched to carriers with roaming charges in
the middle of the call. I have never been charged roaming for those.
It especially happens when in TDMA and I switch to AMPS, which is
roaming on any carrier where I live. It may not apply to you, but it is
what's going on with the TDMA digital network. I don't have GSM in my
city or surrounding area. The carrier I am roaming on with TDMA is
building a GSM overlay exclusively for roamers (Western Wireless), so
even if there is a protocol switching (which I do not think is possible
except between TDMA to AMPS and back again).

AD

It should just switch to Cingular seamlessly and you won't know it even
if the call is over since it could have already switched back to ATTWS.
You have to remember that ATTWS is controlling the signal that the phone
picks up. If you should happen to get dinged for roaming on Cingular in
your home area, you should have a good case to get it reversed by Cust.
Serv.

--
Chris

Please respond on Usenet or Phonescoop.com


[email protected] (Susan Lam) wrote in article
<[email protected]>:
> I am in a small town in Wisconsin. I just purchased a Sony T616 phone
> with ATT GSM service. As ATT just turned on GSM coverage in my area 2
> months ago, the service is not stable and sometimes my phone switch to
> use cingular service which ATT will charge me for roaming.
>
> My phone screen will show what service is in use before I call or
> receive call. My only worry is: if I am talking on the phone and
> stepping from ATT coverage into Cingular coverage, will it switch
> service automatically or will the singal simply dies??
>
> Of course I am hoping the signal dies (instead of switching to
> cingular) while the phone is in use...
>
> Thanks,
> Susan

[posted via phonescoop.com]

DEPENDING ON THE PLAN THAT YOU ARE ON YOU MAY BE TOTALLY RESPONSIBLE FOR
THE ROAMING CHARGES.

ALTHOUGH ATT WIRELESS HAS GSM ROAMING AGREEMENTS WITH CONGULAR,
T-MOBILE, AND OTHERS...IF YOU ARE ON EITHER THE LOCAL OR ONE RATE PLANS
AND ARE WITHIN YOUR HOME CALLING AREA (HCA) YOU SHOULD BE ABLE TO GET
CREDIT FOR ROAMING CHARGES GENERATED FOR CALLS WITHIN YOUR HCA. IF YOU
ARE ON THE NATIONAL PLAN YOU ARE ONLY COVERED FOR CALLING FROM AN ATT
WIRELESS TOWER AND ROAMING CHARGES WOULD NOT BE CREDITED.

[email protected] (Susan Lam) wrote in article
<[email protected]>:
> I am in a small town in Wisconsin. I just purchased a Sony T616 phone
> with ATT GSM service. As ATT just turned on GSM coverage in my area 2
> months ago, the service is not stable and sometimes my phone switch to
> use cingular service which ATT will charge me for roaming.
>
> My phone screen will show what service is in use before I call or
> receive call. My only worry is: if I am talking on the phone and
> stepping from ATT coverage into Cingular coverage, will it switch
> service automatically or will the singal simply dies??
>
> Of course I am hoping the signal dies (instead of switching to
> cingular) while the phone is in use...
>
> Thanks,
> Susan

[posted via phonescoop.com]

your phone may have a feature that allows you to lock onto ATTWS, so that no
call actions can be made when you are not in their coverage area.


"CHRIS LAWRENCE" <[email protected]> wrote in message
news:[email protected]...
> DEPENDING ON THE PLAN THAT YOU ARE ON YOU MAY BE TOTALLY RESPONSIBLE FOR
> THE ROAMING CHARGES.
>
> ALTHOUGH ATT WIRELESS HAS GSM ROAMING AGREEMENTS WITH CONGULAR,
> T-MOBILE, AND OTHERS...IF YOU ARE ON EITHER THE LOCAL OR ONE RATE PLANS
> AND ARE WITHIN YOUR HOME CALLING AREA (HCA) YOU SHOULD BE ABLE TO GET
> CREDIT FOR ROAMING CHARGES GENERATED FOR CALLS WITHIN YOUR HCA. IF YOU
> ARE ON THE NATIONAL PLAN YOU ARE ONLY COVERED FOR CALLING FROM AN ATT
> WIRELESS TOWER AND ROAMING CHARGES WOULD NOT BE CREDITED.
>
> [email protected] (Susan Lam) wrote in article
> <[email protected]>:
> > I am in a small town in Wisconsin. I just purchased a Sony T616 phone
> > with ATT GSM service. As ATT just turned on GSM coverage in my area 2
> > months ago, the service is not stable and sometimes my phone switch to
> > use cingular service which ATT will charge me for roaming.
> >
> > My phone screen will show what service is in use before I call or
> > receive call. My only worry is: if I am talking on the phone and
> > stepping from ATT coverage into Cingular coverage, will it switch
> > service automatically or will the singal simply dies??
> >
> > Of course I am hoping the signal dies (instead of switching to
> > cingular) while the phone is in use...
> >
> > Thanks,
> > Susan
>
> [posted via phonescoop.com]

I believe in your "home" service area on the "local" plan you will not
be charged roaming, regardless of what carrier you use, so it might be
worth it to look and see if the local plan gives you an adequate
coverage footprint. If you are on the national plan, i believe you are
right, you will be charged roaming.

However the chances of your switching from AT&T to Cingular while
actually on a call are extreamily slim. Your phone will likely hold
onto AT&T until the call drops, then do a search and lock onto cingular,
forcing you to re-establish the call. Depending on the roaming
agreements and switches in your area it might be theoretically possible,
but not likely. Much more likely that you'll answer an incoming call
without realizing you've switched over to Cingular. To avoid this you
can switch your phone to "Manual" network search and select AT&T.

--
Dan W.
North Texas
hominid7 "AT" hotmail "DOT" com



[email protected] (Susan Lam) wrote in article
<[email protected]>:
> I am in a small town in Wisconsin. I just purchased a Sony T616 phone
> with ATT GSM service. As ATT just turned on GSM coverage in my area 2
> months ago, the service is not stable and sometimes my phone switch to
> use cingular service which ATT will charge me for roaming.
>
> My phone screen will show what service is in use before I call or
> receive call. My only worry is: if I am talking on the phone and
> stepping from ATT coverage into Cingular coverage, will it switch
> service automatically or will the singal simply dies??
>
> Of course I am hoping the signal dies (instead of switching to
> cingular) while the phone is in use...
>
> Thanks,
> Susan

[posted via phonescoop.com]

There should be no probelms at all. This is not the same thing as
switching from on type of service to another (like going from GSM to
AMPS).

[email protected] (Susan Lam) wrote in article
<[email protected]>:
> I am in a small town in Wisconsin. I just purchased a Sony T616 phone
> with ATT GSM service. As ATT just turned on GSM coverage in my area 2
> months ago, the service is not stable and sometimes my phone switch to
> use cingular service which ATT will charge me for roaming.
>
> My phone screen will show what service is in use before I call or
> receive call. My only worry is: if I am talking on the phone and
> stepping from ATT coverage into Cingular coverage, will it switch
> service automatically or will the singal simply dies??
>
> Of course I am hoping the signal dies (instead of switching to
> cingular) while the phone is in use...
>
> Thanks,
> Susan

[posted via phonescoop.com]