Re: Cell phone signal question

From: Bob Shuman (reshuman_at_removethis.lucent.com)
Date: 08/10/04 

Date: Tue, 10 Aug 2004 08:48:57 -0500

As you will likely see from my return email address, I work at a US
telecommunications company that provides cellular phone infrastructure to
your carrier (AT&T Wireless Services) as well as many other large global
service providers. I can tell you that your phone losing service until it
is powered down and then rebooted is likely a (known) service provider
issue. I would suggest that you call their customer service number and open
a trouble ticket to let them know exactly when and where this problem was
experienced each and every time it occurs.

As to the issue of being dropped when you hand off between cell sites, this
is either an RF or network design/implementation issue (again owned by the
cellular service provider) or indeed your newer model phone is indeed "less
robust" (less receiver sensitivity or higher S/N requirement). I'm not
familiar with the two Nokia models you referenced, but can tell you that I
have also heard comments that some of the newer model "3G" "3G-ready""high
speed data-ready" etc. phones don't provide as much receiver sensitivity as
the older (much less complex) phones. So, in this regard, I do not think
that the AT&T representative was trying to pull a fast one on you. The only
way you could actually confirm this is to experiment with the two phones at
exactly the same time and place to see how they both behave. (This is
because the infrastructure equipment acts differently under different
network load conditions and depending on RF interference which is also
highly time dependent.

Lastly, with regard to AT&T's previously announced conversion from the North
American TDMA standard to the GSM global standard, this could well be
negatively affecting your service since AT&T needs to share (actually
divide) their licensed frequency spectrum into TDMA and GSM specific
components. In high traffic cells this will likely result in calls being
blocked since TDMA capacity has been reduced from previous levels. It also
creates additional complexity of managing the subscriber base with
additional hand off possibilities (to GSM) if the newer more complex phones
support multiple access technologies.

I'd suggest you contact AT&T and let them know you are not pleased with the
service and see what they do for you. By the way, another change that will
be affecting you is the Cingular Wireless purchase of AT&T Wireless if this
is approved as planned. The good news here for you is that Cingular is
following the exact same technological path as AT&T. They too were TDMA
only and are also in the process of converting to GSM and experiencing
pretty much the same growth pains as they implement the phased conversion..

   Bob

"WbSearch" <wbsearch@aol.com> wrote in message
news:20040810081729.22404.00001078@mb-m11.aol.com...
> Not sure if this is the correct forum, so I'll apologise if not.
>
> I have a calling plan that covers the 5 great lakes states. Worked fine
> everywhere, including Minnesota the past 3 years. This summer, in Minn. I
> could not get service north of Duluth. What I found strange, is when I
turned
> the phone on, after about a minute, I got near full signal indicated.
Then
> about 5 - 7 seconds later, it indicated no service, very consistently. If
I
> tried to make a call, it wouldn't. I tried 911 and it went thru fine, (of
> course I ended the call as soon as it rang prior to connection).
>
> The question I have is, it possible that I am being blocked from service
at the
> cell tower? The reason I am suspicious is 1) ATT is moving away from
TDMA,
> trying to get everyone on GSM, and 2) according to the representatives I
spoke
> with, the plan I have is a money looser for ATT. They dropped it, so I
wonder
> if I am being blocked due to agreements they have with the local provider
in
> MN, which ATT probably looses money when I use their cells.
>
> Another question is that when my new phone (Nokia 6360) switches towers,
i.e.
> from roam to extended area, my call is droped. My wifes phone which is an
> older model (Nokia 5165) doesn't do this in the same area. The rep. tells
me
> the newer phones do that and the older phone was more robust. Sound
> suspicious, or am I being paranoid?
>
> Thanks in advance.
>

Relevant Pages

  • Re: TDMA to GSM
    ... Cingular was selling TDMA phones with new contracted service last year. ... Some areas, where there was not enough spectrum to run both technologies effectively, Cingular did a "cold" coverage change, where one day it was all TDMA service, and the next day it was all GSM service. ... During this transition time period, either directly before or directly after the change in coverage, *all* users were allowed to roam on AT&T Wireless. ...
    (alt.cellular.cingular)
  • Re: GSM-only interference [Telecom]
    ... GSM interference problems were well known and kept secret. ... Subject: GSM and TDMA Problems ... with analog providing coverage where digital wasn't available. ... And the sharper the edge of the switch power, ...
    (comp.dcom.telecom)
  • Cellular-News for Thursday 29th September 2005
    ... GSM Arrives on the Falkland Islands ... Cable & Wireless is spending US$1.5 million to bring a GSM network to ... Germany's mobile phone networks have published a Code of Conduct ... China Tops Cellular Subscriber Top 15 Ranking ...
    (comp.dcom.telecom)
  • Re: Does anyone carry a Verizon phone AND an Iphone?
    ... and AT&T sales rep missed a turn and went in the wrong direction when he was supposed to be fishing a tournament as a backseater in our local fishing club. ... Verizon's coverage advantage stems partially from the fact that they went from AMPS to CDMA back in the mid-1990's and didn't have to completely change systems twice like many of the former Bell System carriers that went from AMPS to TDMA to GSM. ... The old AT&T Wireless, which was bigger than Cingular, wanted to move from TDMA to CDMA, but NTT Docomo invested billions of dollars in AT&T Wireless and forced them to move to GSM. ...
    (alt.cellular.verizon)
  • Re: How Long? (AT&T - Cingular)
    ... The overlay of TDMA with GSM is essentially complete. ... Cingular networks. ... inevitably there will be some coverage holes for GSM as compared to the old ...
    (alt.cellular.cingular)