The Roaming Zone-Cellular Roaming Codes & Advice

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.

WEB-EXCLUSIVE DEALS
AT&T
Cricket
Jitterbug
MetroPCS
Nextel
Prepaid
Sprint
T-Mobile
TracFone
Verizon Wireless
Roaming FAQ:

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.

Roaming List FAQ:

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.





HOME | ABOUT THE ZONE | SEARCH THE ZONE | CONTACT | PRIVACY