Preferred Roaming List (PRL) FAQ

1. WHAT IS A PRL?
It's a large but simple file used in most CDMA phones to determine which cellular carriers a phone should access, and in which priority. The phone is often searching all available cellular signals and comparing the results to it's PRL file, and chooses the channel that is most beneficial to the home carrier. It is primarily used to sort among roaming carriers. It is never used to find the strongest signal.

2. WHAT DO ALL THE ABBREVIATIONS MEAN?

On the actual lists you will see some notations:
RM-means your phone will be off your home system and roaming. You may or may not be charged extra.
RM-means your phone will be roaming with a Preferred Carrier and will not be charged extra.
FR-means "Flashing Roam", which means your phone will be roaming with a Preferred Carrier and will not be charged extra.
RM-means your phone will be off your home system and roaming. You will be charged extra, as determined by your plan.
58 or 0058- this is the "System ID" (SID) a unique number that helps identify a certain company offering cellular service in a certain geographic area, and on a certain cellular channel. An SID number higher than 4000 indicated a carrier operating on 1900 MHz ‘PCS’ channels.
123A-Each city, county, or group of counties is identified by the FCC as a "Basic Trading Area" (BTA) with a number. An SID identifies what BTA’s the system operates in. An "A" or "B" indicates which cellular channel the carrier operates on in that BTA.
(D)- A carrier that offers Digital service that is compatible with your phone.
(D/A)- A carrier that offers Digital or Analog service.
(A)- A carrier with analog service only.
Colorado 1-This is the name of a "Rural Service Area" (RSA) that the FCC has designated as having a geographic or political reason to have several BTA’s and/or SID’s grouped together to have carriers offer service over a conveniently located area. Each state may have several Rural Service Areas, usually served by one carrier on one particular channel. Any county named in an RSA may be either the only county in that RSA, or one near the center of several counties. More than one carrier can serve the same RSA, and the same BTA, even on the same channel, but not at the same site.
Priority or More-While your phone consults the PRL in order, from top to bottom, it will take a shortcut to the next highest Priority entry. This makes the search quicker. If you are roaming and your phone loses service, it will first look at the highest Priority carrier in a regional group. That is the "More" preferred place for the phone to look for service, before it then consults the whole list. Numbers, Priority 1,2,3, etc. indicate groups of carriers that are equally preferred to each other.
GEO-Another grouping of carriers by general geographic association to help the phone start looking for the most likely SID's.

3. WHY WOULD I CARE WHAT IS IN MY PHONE’S PRL?

It is important now that cellular companies offer plans with no extra roaming charges if you use your phone on their ‘Preferred’ networks. Consulting the PRL confirms whether you will be charged for roaming in a certain geographic area.

4. WHY ARE THEIR OTHER CARRIERS LISTED BESIDES MINE?

When roaming you could be using a different part of your own carrier’s network, or on completely different networks owned by other companies. You can make calls on these listed networks, even though they are not your carrier’s network.

5. WHERE CAN I GET MORE PRL INFORMATION?

The info above refers to PRL's posted on the MountainWireless web site. For more general information about PRL's, visit Wikipedia.