The following was originally written by & posted by MeatChicken of HowardForums...
Hope this info helps those new to trying to understand *228 updates:
*228 Option 1 - This option does both a PRL update ("option 2") , plus loads the phone with it's "initial needed data" such as it's phone number, home ID etc. This is normally done once only when you get a new phone & need your number OTA programmed into it, but there is no harm in doing it again, as you are simply re-writing the same data over itself into the phone.
Here is the "Scoop" on *228 / Opt 2:
What It DOES Do:
It loads into the handset, over-the-air, a software "list" of Cellular Systems ("companies"), that your phone is allowed to scan for, "After" it loses or can't find a VZW signal. ("The PRL List").
This downloaded software "list" is notated to display the proper text tag / and or "triangle" ( "Extended Area" , Verizon Wireless , or "Roam"), for each system.
The PRL list is set up in area groups, & in a priority order, so for example, in City "A", the phone, after losing a VZW signal, will know to first attempt to find "Alltel" before "Sprint" ect....
If VZW has a system in the area, it is Always higher in Priority than other companies such as Sprint or US Cellular, & will be looked for first, regardless of weather or not another carrier has a "closer" site to your fone.
Most phones will also re-power up/initialize after downloading the PRL.
VZW seems to release a new/updated PRL every 30-75 Days or so.
Doing a PRL update more often, such as once a week, is harmless & will result in simply writing the same PRL file over itself
New Updates can & have both added & removed "partner" roaming systems, depending on VZW, & how they want their phones to roam in any given area.
*228 is a free call.
What It DOES NOT Do:
Contrary to the seemingly endless loads of mis-information & rumor on the net, & sometimes from CS employees, The PRL & *228 Update DOES NOT:
1 - Have Anything to do with any individual "Towers", or accessing newly built "towers". If a company builds a new tower near your home, that new tower is already part of an existing system ("company"), which either is already listed in the PRL, or isn't. Only ENTIRE system ID's are in a PRL. There is no way for VZW to add or block any individual new or old "Towers" by way of the PRL. That's not how the PRL works. Period.
2 - The PRL update can't increase a weak native VZW signal strength issue.
If your phone is already locked onto a "1 bar" VZW signal in a given area, nothing in the PRL list is going to instruct the phone to drop its' native VZW coverage, & look for another companies' signal instead. There are no roaming partners listed in the PRL that have a higher priority than the local VZW signal.
3 - The fone's internal PRL list has absolutley NOTHING to do with anything, once you are " in a call ", & at that time the PRL is as dormat as a game or other not-in -use software entry in the phone. The PRL is not used at all during an actual call in progress.
The cellular system, during a call in progress, has full control, & the system end decides what cells to hand off your call to, & any issues/problems, such as a dropped call, or any other "in call" issues/problems in a given system, have nothing to do with the internal PRL list, & can't be fixed by *228.
4 - Updating the PRL has nothing to due with any problems relating to earpiece volume, battery charging, screen contrast, voice quality ect..... Except that after a *228 the phone might restart, so any odd quirk that might have gone away by shutting the phone off & turning it back on, may also "coincidentally" go away" after a PRL update.
The actual Firmware version of the phone can Not be changed or updated thru a *228 call either. Firmware can only be updated in a Verizon store.
* In many major areas of the USA, including Boston, NYC/NJ, LA & others, & more to come, There are No other extended or Roam PRL system entries for the area, & none planned for the forseeable future. What that means is a PRL update for these people will have no effect on roaming locally, or getting the phone to find a signal in a "no service" spot. Phones here are limited to a VZW signal or "no service". Doing a PRL update in these areas will only effect how your phone works when you travel to another part of the US, AND when you lose VZW signal while there.
5 - The PRL itself in your fone, does Not tell VZW how to Bill your calls, nor send any "billing" data to VZW.
.... Say , for example, You update your PRL, & one of the changes was VZW decided August 3, to make all calls on "Futtbuck County Cellular system" free "extended area calls" on ACI plan, & the new PRL update now allows your fone to display that system correctly as "Extended" instead of "Roam" banner.
If your Buddy did Not update his PRL, & his fone still showed "roam" there, it wouldn't matter, since VZW's billing computer treats calls on that system as Extended, for all handsets on that plan.
Likewise if a system is removed from the PRL, (Such as Sprint recently was in San Fransisco), & someone is using a handset with an older PRL & can still access Sprint there, or those few that can "hack" their fone over to the system, will not be billed roaming, since Sprint SF wasn't "changed" to roam in VZW's billing computer, only handset access to their system was removed in the newer PRL version.
Removing an Extended Area Partner from the PRL Does NOT nessessarily mean that VZW also changed their Billing system, & Most, (if not all), of VZW's recent decisions to remove an exteded parter from the PRL have NOT resulted in a billing system change, simply a handset/PRL system access change.
Last edited by cruznthru; 04-05-2009 at 12:01 PM.
Reason: Titled for Internet Search Engine
Good tip. I think VZW somewhere on their website (forgot where) says what PRL # they are at. They are constantly upgrading it that is why it is a good idea to do this at least once a month especially if you travel a lot.