Does this PDF show where the IMEI number is stored in the SIM card?

Discussion in 'Wireless Internet' started by Johannes, Sep 25, 2012.

  1. Johannes

    Johannes Guest

    Where I live, T-Mobile voice coverage stinks (compared to AT&T).

    However, I had to switch from AT&T to TMobile because AT&T forces
    you to have a data plan for all your kids' smartphones even if you
    don't want your kids to have a data plan (and even if you do not
    buy the phone from AT&T).

    The sole determination of whether or not AT&T penalizes you for using
    "what they consider" a smartphone is based purely on the IMEI number.

    If your child's SIM card IMEI indicates any other phone than a smartphone,
    then, you won't get charged for a data plan (unless, of course, you use
    data, but I always have data blocked - which they will do for you).

    I want to consider whether it's possible to spoof the IMEI in the SIM card.

    Does this PDF I just found searching (which is admittedly dry) show us
    WHERE the IMEI is stored in the SIM card?
    Johannes, Sep 25, 2012
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  2. Johannes

    Mike Ryan Guest

    The IMEI is a part of the phone's baseband, not the SIM card. It can't be
    Mike Ryan, Sep 25, 2012
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  3. The IMEI is in the phone, NOT in the SIM card. Ask tehm for a 2G SIM card.
    No, but you can change the IMEI in the phone.

    In the UK this is a criminal offence, because it allows resale of stolen
    phones. I imagine it is similar in the USA.
    Dunno, but you will be dealing with crooks.
    R. Mark Clayton, Sep 25, 2012
  4. Johannes

    who where Guest

    Not necessarily so. This *may* depend on what plan or other
    arrangement you have/had with AT&T. When we visited the states
    Mar-Jun this year and brought an iPhone, we used pre-paid ($25/mo) and
    by_choice also paid for a data plan ($25/1G/1mo). AT&T were at pains
    to explain that "you can't use that data plan on an iPhone" but it
    works fine (subject to their coverage).
    They don't even get to see your IMEI.
    As others have pointed out, the IMEI is the phone's ID, not anything
    to do with the SIM.
    Yes. But you don't want to go there. Nor do you need to.

    Many - but not all - AT&T shops will refuse to sign up
    itinerants/tourists to a pre-paid plan with a BYO iPhone. This is
    apaprently to protect their own iPhone supply arrangement (2-year
    contract when we looked). But you can still get a SIM/plan without
    identifying the target device as an iPhone and avoiding the
    lecture/grief. In extreme cases, tourists actually have a working
    non-iPhone so that the account can be set up. Afterwards, sweap the
    SIM to the smartphone of your choice.

    I'm not aware of whether the IMEI is ever transmitted on-air as part
    of login or call preamble. If it is, it is of course possible that
    AT&T - tiring of people working around their "attitude" - are actually
    monitoring the IMEI transmitted and initiating blocking based on that.
    who where, Sep 26, 2012
  5. Johannes

    miso Guest

    I don't know about AT$T, but if T-Mobile doesn't have your IMEI, their
    system often thinks you are roaming. I broke a phone and bought a
    replacement on Craigslist. T-Mobile would go back and forth regarding if
    I was on the home network or not. After dealing with them regarding some
    other problem, the service rep noticed I was not on the phone they sold
    me. I gave them the IMEI and all the roaming problems went away. I
    wasn't charged for roaming, but T-Mobile has been blocking tethering
    when roaming, so it is important to let them know you your IMEI.

    Note that T-Mobile is somehow putting UMTS on the 1900MHz band. I don't
    know exactly how this works. But you can now get high speed data in some
    markets with the iphone on T-Mobile. Las Vegas is nearly complete. The
    bay area is being converted.

    Reception problems with T-Mobile are usually due to the quality of the
    phone. The iphone has never been a stellar phone regarding reception,
    though the 4S doesn't suck very much. The iphone 5 is still TBD. It has
    crappy wifi, but it is still being determined if that is due to software
    problems or just more crappy engineering. But it looks pretty.
    miso, Sep 26, 2012
  6. It definitely is - in addition to identifing the make and model of the phone,
    some providers also blacklist the full IMEI of phones reported lost or stolen.
    Robert Neville, Sep 26, 2012
  7. Johannes

    Bob Stevens Guest

    Changing the IMEI is perfectly legal in the United States (as are many
    things not legal elsewhere).
    Bob Stevens, Sep 26, 2012
  8. Johannes

    James Gagney Guest

    I agree.

    In the USA, it's no different than spoofing the unique MAC address on
    your NIC card.

    There's not a single law against it.

    If you do illegal stuff with a phone (like throw it off a bridge to hit
    someone on the head) then it's illegal - but it's not the spoofing of the
    IMEI that's illegal - it would be using the phone to blow up an IED or
    something else that is already covered by a bazillion laws.

    So don't fret about the UK & India crowd.
    They know not our more rational laws.
    James Gagney, Sep 26, 2012
  9. Johannes

    Johannes Guest

    That's interesting!

    Then what 'do' they look at to determine if your phone is a 'smartphone'?
    Johannes, Sep 26, 2012
  10. Johannes

    Johannes Guest

    This is a common misconception (unless I'm missing your point).

    As everyone knows, once you have service, you can swap your SIM card into
    any ATT or unlocked phone - and it will work just fine (I've done it many

    Of course, every carrier asks for 'an' IMEI when you first sign up with
    them - but - that IMEI a mere technicality (I'm not sure 'what' they do
    with that number because it's not meaningful). In fact, I don't think my
    current T-Mobile IMEI is anywhere near close to the original IMEI I gave
    them over the phone when I first started service, simply because I've
    changed phones so many times since then, simply by inserting the SIM

    The problem is that AT&T clearly 'says' that if they detect a 'smartphone'
    being used by my kids, then they will automatically ADD the most
    expensive data plan within 48 hours.

    Now, I don't know if they actually 'do' that - but they certainly 'say'
    they will do that. I asked them how they know if it's a smarphone and
    they say they keep a list of smartphones on hand.

    I asked what if the smartphone isn't even one they sell - and they said
    they keep a list of 'all' smartphones on hand.

    Now, I only know what they clearly say to me - I don't know if they
    actually 'do' this. But, if they did - I consider that unethical business

    Why should I be forced to have a data plan for my children when I want
    them to use the phone's WiFi while at home and to NOT have a cellular
    data plan?

    Anyway, luckily T-Mobile doesn't have this rule - but, if AT&T doesn't
    use the transmitted IMEI number to determine whether a cell phone is a
    smartphone or not - then the question morphs to:

    Q: WHat 'does' AT&T use then to determine if you put your SIM card into a
    Johannes, Sep 26, 2012
  11. Johannes

    Johannes Guest

    I use T-Mobile currently. There is no way they have my correct IMEI
    because I've changed phones multiple times since I started my T-Mobile

    In fact, my kid recently went swimming with his phone, and I just bought
    a new T-Mobile Android phone at Target for $100 so my kid and I are both
    on T-Mobile and there is no way I called them to tell them that which
    they don't even need to know.

    BTW, my plan is the basic family plan - which has - to my knowledge, no
    roaming charges.
    Johannes, Sep 26, 2012
  12. Johannes

    Johannes Guest

    Almost all my phones are unlocked - and the reception is clearly the
    signal because nothing else changes but the SIM card when I pop an AT&T
    SIM in versus a T-Mobile SIM card.

    Even on my kid's cydia-enabled iPhone.
    Johannes, Sep 26, 2012
  13. Johannes

    Johannes Guest

    Please tell me more.

    I don't understand what a 2G SIM card even is.

    Googling, I found this blog:

    But I'm not sure how that will help.

    I don't even WANT data. I just want voice & text.

    You can't get just voice & text with AT&T if you have what they consider
    a smartphone.

    So can you clarify how 2G will help?
    Johannes, Sep 26, 2012
  14. Johannes

    Johannes Guest

    When I was originally on AT&T, and when I complained to the FCC about
    them, I got a call from an AT&T VP who had a list of EVERY phone I ever
    used on my plan.

    They based all that on the IMEI transmitted.

    So, they're DEFINITELY 'monitoring' the IMEI ... otherwise there would
    be no need for this thread.
    Johannes, Sep 26, 2012
  15. Johannes

    Johannes Guest

    I thought so!

    I'm no genius, but, it's disconcerting how much mis-information is out
    there! Very few people actually seem to know what they're talking about.

    Again, I'm not putting myself on a pedestal, but let's cover the myths
    that have been proposed in 'just' this thread.

    1. Myth: Spoofing the IMEI is illegal in the USA
    Reality: It's not illegal in the USA (legal group added).

    2. Myth: The carrier must have the correct IMEI on record
    Reality: You can borrow a phone & put your SIM card in it and your phone
    works just fine; besides, the carrier knows your IMEI at all times anyway

    3. Myth: The IMEI is in the SIM card (this was one I suggested wrongly!)
    Reality: The IMEI is apparently stored in firmware in the phone itself

    4. Myth: You're dealing with crooks if you change the IMEI
    Reality: That's like saying you're dealing with crooks if you change your
    unique MAC address or your hostname of your PC. What's illegal is doing
    illegal things with the phone - not simply changing a number.
    Johannes, Sep 26, 2012
  16. Johannes

    miso Guest

    There are no roaming charges with T-Mobile, at least in the USA. But you
    lose the right to tether when roaming. You do not lose data connectivity
    to the phone, but only if you tether. I kind of thought I made that
    clear in my post, but it doesn't hurt to repeat it.

    So if they DON'T know your IMEI, they may think you are roaming. Or it
    could be a coincidence that when I gave them my IMEI, the roaming issue
    went away.

    I have talked to T-Mob about using different phones since I have an
    Android also that is on T-mob frequencies. They don't care what I use,
    but would have to set up data differently if I left BIS. I don't really
    like the Android phone, but needed it for one critical app that use via
    Bluetooth. I get data to the phone via wifi, so I don't even bother
    putting a simcard in it.
    miso, Sep 26, 2012
  17. Johannes

    miso Guest

    For edge, there is no need to change the simcard. Any decent phone, even
    an iphone, can read the signal strength. UMTS is a different story.
    miso, Sep 26, 2012
  18. Johannes

    miso Guest

    Let me explain myself for the third time. A T-mobile branded phone, in
    this case unlocked, with T-Mobile simcard, can periodically appear as
    roaming. This is not a myth. I have have this happen. When I gave
    T-mobile my IMEI, the problem went away.

    I hope I have stated this clearly.
    miso, Sep 26, 2012
  19. Johannes

    miso Guest

    Buy the ipod touch. Case solved.

    You can bitch, rant and stomp your foot all you want, but AT&T has the
    right to make up any rule they want and can sue you, send the case to
    small claims, or a collection service. It is a contact. You abide by the
    contract or face the legal consequences. At best, they will just
    terminate your service.

    T-Mobile wants you to bring iphones to their system. The company is
    number 4; they need the business. In some localities, you will get 3G
    service. Check out
    They call it 4G, but really is is 3G.
    miso, Sep 26, 2012
  20. Johannes

    miso Guest

    Using "UMTS Networks" as a reference, the UE (user equipment) needs an
    IMEI (international Mobile Subscriber Identity), which the book refers
    to as "unalterable equipment identification." There is no comment on
    changing this code or the legality thereof.

    The IMEI is feed to the CN (Core Network), but there is no requirement
    to use it. I interpret this as the phone company can do whatever they
    want with the IMEI. Log it, ignore it, charge the sucker a fee, etc.

    [UMTS Networks, 2001, John Wiley and Sons.]
    miso, Sep 26, 2012
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