THE ROAMING ZONE PRL FAQ:
Frequently Asked Questions About our PRL
- What is a PRL?
Preferred Roaming List. It's a large
simple file used in most CDMA phones
which cellular carriers a phone should
and in which priority. The phone
searching all available cellular
and comparing the results to it's
and chooses the channel that is most
to the home carrier. It is primarily
to sort among roaming carriers. It
used to find the strongest signal.
- What Do the Abbreviations on the PRL List
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
RM-means your phone will be roaming with a
Preferred Carrier and will not be charged
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
(A)- A carrier with analog service only.
Colorado 1 (or CO-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.
- Why Should I Care What's 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
- Why Are 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
- How Do You Determine What's in a PRL?
There are several methods. Many users extract
the information from their phones
the information with the FCC database.
method is to compare the experience
knowing what their PRL version is
at their phone's "version"
and then posting which network they
while roaming. It is from these reports
can post this information. Actual
lists are copies from other web sites
related to any wireless carrier,
is not guaranteed.
- Why Aren't There More Current PRL Interpretations?
You may have wondered what happened to the
more recent Preferred Roaming List (PRL)
“Interpretations” that appear on our PRL
pages of the Roaming Zone. It seems our interpreters
have "retired." To create an accurate
text of these lists takes quite a bit of
work, and so far, that work has been entirely
When those who interpret the PRL as a hobby
find something else to do, the rest of us
go scrambling for another source…but there
isn’t any. We offered to pay to have PRL’s
decoded, but once the fun is over, it becomes
too much like a job...and we understand that.
We have offered these PRL volunteers the
control of these web pages, only to watch
them create their own. The sad result is
that once that happens, they lose interest…and
we lose our source.
There are a handful of users who take the
time to save and even post the actual .prl
file, but for most of us, they’re just a
list of meaningless numbers. We have considered
at least posting the raw lists so that serious
PRL fans can at least look at the order of
things and look for their favorite System
ID (SID). We hate to just leave you with
so little detail, but at least you can decide
whether it’s useful.
Fortunately, the major carriers need less
roaming, so we have less to report. Eventually,
the PRL may become nothing more than a housekeeping