FNetV1

Does the Samsung Galaxy S3 tri band have an external SIM slot?  I do not recall on the later tri band variant, but the original Galaxy S3 does not.  And if no external SIM slot, then there is nothing to unlock for international roaming, which is either unsupported or limited to Sprint's international roaming agreements.

 

AJ

Physically speaking, I dont see any SIM slot, but some people are saying that the SIM could be hidden behind a sticker or a compartment/case protected by screws, etc.  If not at all, it would be good to know if this particular phone at least has a functional GSM radio that can be use to assist the phone to roam on GSM based network when offshore for people who would like to at least take advantage of some type of roaming features.  This is exactly what Verizon did with their CDMA Galaxy S3 variant, they released an update that enables GSM to work offshore so that their customers can be able to roam on GSM international networks makes extra money on roaming fees, etc.  Just figuring out if Sprint did the same thing, since Samsung had confirmed that they only released one Galaxy S3 for the US, and all variants had the same type of technical abilities, just that depending on the carrier some might have its GSM radio active/CDMA disabled while others might have CDMA active and POSSIBLY GSM active only for international roaming uses (this is what I am trying to figure out in the case of Sprint) just like Verizon did.

Nope, that's what the SIM card is for. PRLs are CDMA only, and control non-roaming connectivity as well (prioritizing some channels over others, some carriers over others, etc). The device will not connect to a network, or even channel on a network, via CDMA that isn't in the list.

 

The SIM controls what GSM (including LTE) networks your phone connects to. It may have some defaults to scan for (Sprint starts with B25 or B26 I believe) or other "smarts" on the SIM microcontroller, but if it doesn't find native service (and the phone doesn't "remember" a previously connected network), then it starts cycling through all the bands it supports looking for something. It'll attempt authentication on every network it finds, if it fails, then it moves on. Usually once on a roaming network that network takes over and can move the device to another band or technology (say GSM to UMTS/HSPA).

 

The modem does sort of keep a memory of connected sites and bands, and tends to scan for them first. So when entering a new country it will often take a bit (several minutes) for it to find roaming service. Once it does though it'll remember and quickly hop back on it if you reboot or airplane toggle or anything.

 

Sent from my Pixel XL

Thanks, your post has been very informative.

I was reading an article how many carriers were GSM unlocking by default the Samsung Galaxy S3 phones to be able to roam overseas.  I read that Verizon did it, but was not able to confirm if Sprint did it.  Do you know if the Galaxy S3 Triband (SPH-L710T) has its GSM radio unlocked by default?  How can I test to see if my GSM radio is actually unlocked for international use, I have the MSL code and would like to unlock it or enable the GSM radio if at all possible if its not already enabled.

Yes. Entirely outside of a few select cruises I believe.

hmmm interesting, so Sprint allows CDMA roaming on cruise ships (eg. Carnival, Royal Caribbean, etc), so I suppose for those you might need a 55xxx/56xxx based PRL IF you plan to take SOME advantage in roaming on a cruise ship?

Also, I have been doing some research in reference to the Samsung Galaxy S3 and how some providers like Verizon (I dont know about Sprint, but must likely too) has unlocked the GSM radio, or enabled the phone's GSM radio to actually work when you travel internationally, is this true for the SPH-L710T (Triband Galaxy S3)? for Sprint?  The only hint that I have here is that the phone gets a "world phone" level of PRL (55xxx) while the Sprint Moto G3 and a Sprint HTC Desre 510 both have the non-world phone based PRL of 25xxx.  All what I know is that I have never called Sprint to enable the Galaxy S3 unlock for International use, but based on the article I read, I think Sprint might have auto unlocked its GSM radio for international roaming purposes, or that the Galaxy S3 do come with its GSM radio already unlocked for international use by default.  

I though that the "PRL" controlled everything related to the phone's roaming capabilities (well partly its true only for CDMA based networks), I didn't know that a phone could connect to a GSM network offshore totally independent to what the PRL within the device itself says where you can geographically have "service".  

Generally much smarter to use wifi (if available) on the cruise ship as the cost can be far cheaper.

 

Sent from my LG-LS997 using Tapatalk

Thanks for the reply.  I am aware that I am use wireless, but I am more interested technically wise, if a 25060 PRL, or in other words, a 25xxx PRL will connect to internationally CDMA partners, or will the PRL *HAS* to be a 55xxx (residential world phone) or 56xxx (corporate world phone), so if you have a sprint device and it has a 25xxx PRL, and you were to travel, will that on it self be a barrier to not being able to "roam" internationally?

I have Sprint and my phone is a Moto G 2015 XT1548.  I am about to go for vacation on a cruise and would like to make sure I will be able to roam internationally.  Sprint has an International roaming agreement with the cruise ship I will be on and most of the countries I will be visiting have CDMA towers so that foreigners can "roam" specially on the tourist attractions which will be the areas I will be at.

I updated my PRL a few days ago and it is: 25060

Going by the list, it falls within the non world phone PRL's.

However, what I find ironic is that I have a NON -activated sprint Samsung Galaxy S3 Triband that was precisely my previous phone, well that PRL is 55060 and according to the first two letters of that PRL it falls within the "World Phone" category, so I guess according to sprint my Previous phone is a "World Phone" that can work in any country, presumably even being able to roam in GSM networks on top of being able to roam on CDMA networks (my assumptions), where my much newer Moto G3 XT1548 is labeled as a "Non World Phone" whose meaning is not entirely clear for me on what that means, if it means that the XT1548 wont work outside the USA full stop or what.  

So, should I worry that my PRL is 25060 (residential non world phone) and not within the 55xxx range (residential world phone as my old Galaxy S3 is)?