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  1. #1
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    Cingular GSM Problem

    Has anyone else had a problem with Cingular GSM service? I brought 3 unlocked tri-band phones from the Far East and they worked for about 6 months and then all of a sudden they just stopped working. All 3 in the same week went from perfect connections on 1900 Mhz to intermitent.

    I have an O2 Xda IIi (an HTC PDA) which is sweet, a Nokia 7710 PDA with a huge display Nokia N90 which takes great pictures.

    I called Cingular and they said those phones don't work on their system. When I told the "technician" they worked for months she just clammed up!

    I read that Cingular is going strong on the 850 Mhz band. THere is no information out there about the 1900 Mhz band. Does anyone have any news?

    Thanks.

  2. #2
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    Cingular Problem?

    My phone Motorola V-180 started having problems a month ago.
    CS sent signal over the air and it started working again.

    My wifes Razr did the same thing 2 weeks ago. CS same fix.
    CS Thought she had a different phone also.

  3. #3
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    Quote Originally Posted by INEXCO
    My phone Motorola V-180 started having problems a month ago.
    CS sent signal over the air and it started working again.

    My wifes Razr did the same thing 2 weeks ago. CS same fix.
    CS Thought she had a different phone also.

    wat do you mean that they sent a signal over the air? When I called Cingular all they said was my phone was the problem and I was on my own.

  4. #4
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    Cingular is using 850 freq in a lot of places in US. IF your triband does go below 900, then you are not going to get reception. Cinc has been moving to 850 and your phone might have worked back when they were still using 900? Try going to Cinc FAQs for more info.

  5. #5
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    Thanks for the suggestion Leesa. I tried looking on their site and they do not address frequencies that they use. I spoke with customer service and tech support and all they could say is it is my phone and they don't support it because I did not buy it from them.

    When I tell them it worked for months and then both mine and my wifes stopped working they just go silent. I really want the O2 Xda IIi to come back to life as it is the cooles pda I have found. The screen is huge and I miss it.

    Thanks

  6. #6
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    I got this off HowardsForum:
    "Cingular runs GSM on 1900 MHz in some markets, 850 MHz in others, and has a dual band 850/1900 MHz network in others. To find out what frequencies are used in your market, check ww.wirelessadvisor.com.

    If your area is one where Cingular is strictly 1900 MHz, you will have no issues using a GSM phone with just 1900 MHz. If your area is strictly 850 MHz, a GSM phone with 850 MHz is required. In dual band markets, a phone including 850 MHz may be required, or may not be. This depends on whether the Control Channels are running on 850 MHz. The control channels keep you connected to Cingular while not using your phone. Cingular has been switching Control Channels over to 850 MHz in dual band markets as of late. This means a 1900 MHz phone will get No Service, as it can not access the 850 MHz Control Channel, even though Cingular is running service at 1900 MHz!!"

  7. #7
    Registered User thaxman's Avatar
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    gmat, what bands are these Asian phones? 900/1800/1900? 800/900/1900? 800/1800/1900? Since Cingular owns some of the very 1st cellular liscenses granted, places such as LA and Dallas, they run 800 in some cities (they changed terms to 850 since alot of people know 800 was originally set up for analog and they want to keep people from relating their service to analog, but its the same freq. anyway) But there are only 2 800 MHz liscenses in any specific city in the nation, and Verizon and Cingular don't own all of them. So when the FCC allowed 1900 MHz liscenses, Cingular's former companies, SBC, GTE, BellSouth and most notably AT&T took out 1900 liscenses to get into the bigger cities they didn't own in the 80s. That is why they use dual-band (minimum) phones, or else their customers would only have service in parts of the country (not full regions, but a national jigsaw puzzle missing lots of pieces) Very VERY rarely is 800 MHz spectrum for sale, and Alltel is the company doing 95% of the purchasing, as they buy up smaller regional and local carriers that have operated in the same towns for 20+ years, so Cingular is unable to convert exclusively 1900 MHz cities to 850 MHz service, since it flat out doesn't own the spectrum of radio waves in that frequency.
    Now there are some places like Miami where the old AT&T owned one band and one of the other parts of Cingular owned another band, allowing the consolidated company to operate both 800/1900 frequencies, but unless in these markets Cingular lost alot of customers, they should need both bands to prevent a clogged network.
    As far as OTA reprogramming, Cingular most likely has a list of GSM phone models they have sold in their lifetime and have programming code for them, but not for foreign phones.
    Another thing I had been hearing is this: since Cingular absolutely insists that all phones on their network come from them exclusively, they may be looking for IMEI mismatches (every phone has a serial#, even if only the SIM# gets used) and shutting down the phones that they don't recognize. Their main reason for this (no matter what flunkies at customer care say) is so that you will have the proprietary data setup to buy ringtones and games directly from them, which is programmed into phones they buy directly from the manufacturer, but not in generic unlocked phones. Don't care to buy their crap? Doesn't matter, because one day your 6-yr old may download something without your approval and since they won't reverse your purchase, they just profited from their policy.

  8. #8
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    Quote Originally Posted by thaxman
    gmat, what bands are these Asian phones? 900/1800/1900? 800/900/1900? 800/1800/1900?
    The phones are 900/1800/1900. So I am suspecting Cingular dis something to their 1900 band in the Houston area recently.

    You mentioned IMEI matching. I understand every phone has a seriel number or IMEI number. Are you saying that when my phone is on the air, the phone transmits the IMEI number somehow and Cingular can select ones to shut off?

    I went to gsmworl.com which is the site for the GSM Association. They have Cinghular maps that say they cover Houston on 1900 and greater coverage on 850. Now you have me wondering about this IMEI matching which sounds like something out of Orwell's Animal Farm.

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