What does it mean and what its function?
Best chosen answer.
Well, that was pretty long.
Basically, a PRL tells your phone where cell towers are.
And from past experience with writing new prl's to the phone using QPST it usually doesn't accomplish much, but it does give me another reason to tinker with my phone.
The easiest answer is that a PRL is a list of towers that your phone is authorized to connect to. When your phone picks up new towers with better signal it attempts to hop to that tower, but it can't use all of them due to your service provider.
Virgin Mobile uses only Sprint towers (and Clear for 4G). The PRL for VM phones will ONLY contain Sprint and Clear towers.
If you have Sprint service you pay extra so that you can use not only Sprint, but also other provider's towers... like T-Mobile and other carriers.
The PRL file will be different for Sprint vs. Virgin Mobile service due to those differences in authorized towers. It can also be used to give preferential treatment to business customers by allowing them to connect to towers that regular customers can't use.
It is also why all this talk of a PRL change makes little difference. If you are getting a better signal/speeds then it is because you are connecting to a different tower than you were previously, NOT because the tower you were using is all of the sudden faster.
Also, people will claim they can make a PRL that allows you to connect to other carrier's towers... that may be true, but that carrier will also report you to VM (by tracking your phone's ID in their system) and they will cut off your account permanently.
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