|
|
|
FREQUENTLY ASKED QUESTIONS ABOUT ROAMING
Answers about how your cellular phone behaves
when roaming and how to use the lists and numbers on this site.
|
|
|
How do I know my phone is roaming?
There is a word or indicator on the screen
of your phone. Indicators can be a Triangle
or an "R", words can say "Roam"
or "Extended Network". Sometimes
the name of the network you are roaming on
appears.
How can I get a different PRL?
There are several methods. The easiest is
to choose when you download (by pressing
*228 SEND) the PRL. You can choose to keep
an old PRL and avoid a new one, or jump on
a new one as soon as you know its contents.
Another method is to download a specific
PRL file from the internet, then upload it to your phone. It is also
possible to edit the PRL file (.prl) in your
phone. However, just because your phone then
can access different roaming carriers, you
may not be billed the way you expect.
|
|
How do I call someone who is roaming in another
state or country?
You just call their normal cell number. If
their phone is on while roaming, their cellular
carrier will have a record of where they
are and route your call appropriately.
How do call back to the US when roaming outside
the country?
Normally, you enter the same sequence of
numbers the locals use. In some cases you
add a "01" or a "001"
before the US Area Code and number. There
is a short cut for most GSM phone users (AT&T,
T-Mobile, etc). By entering a "+"
before your number. The foreign system figures
out the roaming codes automatically, but
you still must enter a "1" before
all US numbers. Unless you have these codes
programmed into your phone book, none of
your entries, including the voice mail button,
will work.
What does a flashing Roaming indicator tell
me?
Flashing normally tells you you are roaming
on a "friendly" system and should
mean you won't receive any roaming charges.
A solid indicator could mean you will receive
charges unless your wireless plan includes
free roaming.
My plan includes "No Roaming Charges".
Can I ignore any roaming indicators?
Usually, yes. However all plans are not equal,
so you need to ask your carrier what kind
of roaming will cause extra charges. Most
phones won't roam on systems that will produce
charges, but that is not universally true.
My phone says I'm Roaming. How do I know
what network it's using?
The easiest way is to enter an invalid phone
number, like "1234" and try to
make a call. The system should return a recorded
error message that may include their name
or a number that identifies their SID. You might also check among your Display
options. There should be a menu selection
for "Network" or "Other Information".
Most phones will show an "SID"
number. Compare that to our SID List to see what system you are using. Some phones
show the network name on the screen.
WHAT IS A PRL?
Preferred Roaming List. 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.
WHAT IS AN SID?
System IDentitification number. This is a 15-bit numeric identifiers used by cellular
systems to identify the home system
of a
cellular telephone and to determine
its roaming
status.
WHAT IS AN MNC?
Mobile Network Codes are used in combination
with a Mobile Country Code (MCC) to uniquely
identify a mobile phone operator/carrier
using GSM and iDEN cellular networks and
some satellite mobile networks. The MNC is
a series of 3 digits following the Mobile
Country Code (MCC).
WHAT DO THE ABBREVIATIONS ON THE PRL LISTS
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 (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 WOULD I CARE WHAT IS IN MY PHONE’S PRL
OR MNC?
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.
WHY ARE THERE 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.
HOW DO WE DETERMINE WHAT'S IN A PRL?
There are several methods. Many users extract
the information from their phones and compare
the information with the FCC database. Another
method is to compare the experience of people
knowing what their PRL version is by looking
at their phone's "version" screen,
and then posting which network they are using
while roaming. It is from these reports we
can post this information. Actual PRL text
lists are copies from other web sites not
related to any wireless carrier, so information
is not guaranteed.
|
