for VZW folks- How often to update PRL lists?

Discussion in 'iPhone' started by diegoesk, Feb 15, 2011.

  1. diegoesk macrumors regular

    Dec 19, 2010
    Im an ATT defector and never had to do such.. but I read somewhere about PRL roaming lists...

    How often are you supposed to update the PRL Roaming list (*228, then pressing option 2)?
  2. bigtallguy macrumors member

    Jun 15, 2010
    When I was on Verizon a rep told me about once a month is a good idea, no need to do more often unless you are traveling a lot.
  3. shadrap macrumors 6502

    Jul 6, 2009
    I never do it. Never knew I needed to. Being serious
  4. shadrap macrumors 6502

    Jul 6, 2009
    What does it do?
  5. bigtallguy macrumors member

    Jun 15, 2010
    On Wikipedia..."The PRL indicates which bands, sub bands and service provider identifiers will be scanned and in what priority order. Without a PRL, the device may not be able to roam, i.e. obtain service outside of the home area. There may be cases where missing or corrupt PRL's can lead to a customer not having service at all."...

    The rep basically told me it is a list in your phone of where the cell towers are located and so for example if a new cell tower was added, without updating your list, your phone would have no idea it was there.

    If anyone knows more or I am mistaken, please correct me or explain further but this is basically what I remember.
  6. tsolt macrumors regular


    Feb 2, 2011
  7. lanthom macrumors member

    Jan 11, 2011
    I usually do it once every couple of months. It usually hits me that I haven't done it in a while so I do it. It only takes a couple of minutes so not a big deal.

    My work phone they send us an email about once every 3 months reminding us to do it on our buisness phones as well.

    I had a rep tell me one time that if you start having dropped calls to run the update to make sure the phone has all the available towers loaded.
  8. emt60 macrumors newbie

    Jun 12, 2009
    The PRL is a list that CDMA phones use to determine what priority a roaming network has over another roaming network, assuming the phone can't find a native signal.


    As long as your phone is able to connect to a Verizon Cell Site, the PRL is not used.

    If a native VZW cell site can not be found, the phone will scan what systems are available, and then consult the PRL for guidance on what system it should connect to.

    Geographic collections of a carrier's cell sites are divided into Systems, denoted by their SID. For example, in the New York City region, Verizon operates System ID 22.

    Lets say you were somewhere where no VZW signal was present, but the phone was able to detect a MetroPCS SID, and a US Cellular SID. One SID would have higher priority than the other in the PRL, and that is the system the phone would connect to.

    The PRL has absolutely nothing to do with individual towers. When a carrier brings a new tower online, it is programmed with the SID of the system it belongs in. So if Verizon puts a new tower up in NYC, it will be programmed with SID 22, so your Verizon phone would recognize it as a native VZW signal.

    In the past, VZW updates their PRL every 1-3 months on average. Most of the updates are meaningless for the vast majority of users who live in markets with strong native Verizon coverage. That being said, it is always a good idea to update the PRL pior to traveling out of your home region.

    Hope this info helps anyone who is new to VZW.
  9. Onthelo macrumors regular


    Jan 30, 2011
    Santa Clara - Bay Area
    never done it with any of my bb, smart phones for 5 years now.. Didn't even know about it.. thanks for the insight
  10. anthonybkny macrumors 6502


    Feb 15, 2011
    Just did it. Maybe a coincedence, but im getting one more bar than i was before i did it. Ill take it
  11. svenn macrumors 6502

    Aug 11, 2010
    I'm pretty much reiterating what has been said, but I had VZW for years before I had heard anything about this. I typed the magic code and got some confirmation that it worked, but I noticed zero difference after that.
  12. maflynn Moderator


    Staff Member

    May 3, 2009
  13. mreg376 macrumors 65816


    Mar 23, 2008
    Brooklyn, NY
    Nope. Has nothing to do with cell towers or reception. As others have said here it's a list of non-VZW partners that your phone uses when necessary. Used to be a time when if you called customer service for something else they would complain if you hadn't updated the PRL but I don't know if they still do.
  14. kdarling macrumors P6


    Jun 9, 2007
    First university coding class = 47 years ago
    They usually recommend doing it before traveling outside the USA, to make sure the roaming list is up to date.

    I do it once a year before vacationing in Mexico.

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