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Frequencies for Cingular & AT&T in SF Bay Area

Discussion in 'Tech Talk' started by Jack Straight, Nov 11, 2004.

  1. I need to buy some mobile phones for a test system. I currently have phones that work at 900/1800/1900Mhz, and they work fine for Cingular and AT&T in the San Franciso Bay Area.

    We recently took them to Ohio, and they would not work for Dobson Communications (CellularOne). They use 850Mhz.

    My question is, if we buy some 850/1800/1900 or 850/1900 phones, they should work for Dobson, but will they work for Cingular?

    Yes, I will call Cincular also, but it takes a long time to get through to a technical person.
  2. 0100010

    0100010 Millennium Member

    Sep 15, 1999
    Do any manuf. make 850/1900 phones?

    If they exist - are they on the same carrier type? TDMA/CDMA/AMPS/GSM

    If you do find a phone compatible to both frequencies and that will work for both transmission types (or if they happen to match), then all you would really need is Cingular to add that phones ESN to its subscriber pool.

  3. irobinson

    irobinson Semper Absurda

    Mar 6, 2000
    So. Cal.
    If it is 850MHz it is most likley some kind of CDMA or TDMA system. Old AT&T used TDMA800 for their digital network. Verizon uses CDMA800 and Sprint uses CDMA1900.

    Cingular and newer AT&T phones (soon Cingular anyway) use GSM1900 for their transmission (also a TDMA-type setup but different than the old AT&T).

    Nextel uses iDen which is also a TDMA based technology from what I have heard.

    A GSM phone will not talk to a CDMA/TDMA network and vice-versa. No manufacturer makes an AMPS/CDMA/TDMA and GSM phone all-in-one. It wouldn't be practical. They do make CDMA 800/1900 phones but I have no idea who does. You can buy GSM 900/1800/1900 phones all day.
  4. mattyk6


    Sep 30, 2001
    Keep us updated!
  5. unixglocker


    Jan 7, 2003
    How about get a different carrier that works in all states?
  6. The 6620 and 6340I worked great at Dobson. We even bought a 320 while there.

    One thing, my Cingular phone seemed to burn up the battery quicker when roaming. Or maybe it is just getting old.

    Unixglocker: We don't want a carrier that works everywhere. We are doing testing for different carriers, so we have to use their networks. We do some inter-carrier testing, and that is where the numbers get interesting.

    For example, most carriers can deliver an SMS within their network in under 10 seconds. But between networks, it can be 30 seconds to 30 minutes! Strangely, we have seen the times increase steadily, then fall back hard to 30 seconds.
  7. Goober35

    Goober35 1911 member.

    Nov 29, 2004
    850mhz is a gsm. TDMA/CDMA is old school **** like WWII ****. They dont even work the same. GSM is in 0' and 1's aka bionarly (sp)
    cdma/tdma is anilog.
  8. TDMA & CDMA are not the same at all. CDMA is binary (digital) also. In fact, my understanding is that the new UTMS standard uses the CDMA technology for the radio side, and GSM technology for the switching side.

    CDMA is not old school...there is CDMA2000 and other modern standards.