I have a somewhat technical question about how handsets acknowledge that they are "roaming".
What is responsible for this?
I mean, I understand the general roaming process: phone connects to network, network checks user and finds that they're not one of their own, they find who the user is with and create a "temporary" profile for that user, which is then sent back with a bill to the actual carrier.
However, how does the phone itself know that it is roaming (for purposes of things like disabling data roaming)? Is it some sort of "token" sent to the device by the carrier? Is it done through the SIM card, which is locked to that one carrier and flags any other carrier under roaming? Is it something else entirely?
On a somewhat related note, what establishes the network's "name" that the user sees? Is it purely pushed by the carrier? Can the SIM card manipulate that field in any way (does it play a part in the process, or is it just playing the role of a dumb pipe)?
Hope this question makes sense -- I can clarify if need be!
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I'm working on a project for work, one of the stipulations is being able to lock a single SIM card to a device - ie; if the phone is started up without the SIM it was provided with, it will refuse to start up unless the correct security (not SIM) code is entered, or the correct sim is put back in the phone.
We are currently doing this with nokia handsets with great success, but we're also looking for more customisable phones.
Soooo.... Is this possible with android? All i've found on my handset is weather or not my phone prompts me for the SIM PIN.
The reason for this is a large number of handsets we're being "lost" and we were a little suspect of how often some employees were "losing" their phones. After we started locking phones to SIMs, far (far far far) less devices were being lost...
If anyone could point me in the right direction, I'll gladly give you an internet high-five!
Sorry to bring this up again, but the other threads on the topic are either very old, for different phones, or both.
I'm using an MVNO, specifically Bob (232-11), who use the infrastructure of A1 (232-01), so technically I'm roaming 24/7. Sadly the Desire can't seem to tell the difference and refuses to use data services unless I allow data roaming. Of course that can get very expensive very quickly if you live near the border ...
Once upon a time that was considered an Android bug (or an idiosyncrasy at least), only HTC seem to be the only ones who haven't come up with a solution by now:
HTC Legend (stock 2.2) - needs data roaming on
HTC Desire S (stock 2.3) - needs data roaming on
LG P500 (Optimus One, stock 2.2) - works fine with data roaming off
Samsung i5700 (Galaxy Spica, CM6) - works fine with data roaming off
Samsung Galaxy S - most custom ROMs and even newer stock ones work fine with data roaming off
So, obviously there's a way to fix this in software, maybe a whitelist or something? Or an option to go by MCC only, which is crude but would work for me? (I know that there's supposed to be apps that warn you when you're really roaming but I can't say I really trust those.)
I found a nice solution over at the SGS forums: http://forum.xda-developers.com/showpost.php?p=12693880&postcount=5
Of course it needs root, which we don't have yet on the DS, but still, it's a first, or rather second step.
I also have a MVNO. I suggest you enable data roaming and manually select your network operator, instead of leaving it to automatically connect to any other operator available in low coverage areas. This should prevent costly roaming charges from happening accidentally (since you would have to manually switch operators when abroad).
The only other problem is that Sense seems to think that your current location is not "home" so world clocks and stuff like that show one more location than needed. Of course some programs, like Spotify, always complain that you're roaming; that's a small price to pay for a much reduced phone bill .
igalan said:
I also have a MVNO. I suggest you enable data roaming and manually select your network operator.
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That doesn't work in practice (at least, it didn't on any Android phone I ever had) because there isn't actually an option to lock the phone to a particular network. You can chose a network, sure, but the phone will still switch when it thinks that it has to.
Oh well, there are two options, one to automatically choose the network and another to manually select it. Supposedly once a network has been selected manually it won't jump to another one. But if you say it doesn't work, I take your word, I can't test it.
I've read on a few places that network providers tend to block users from using their voice and data simcard inside tablets, either by reducing speeds or altogether preventing it.
Would anyone know how this is implemented , probably via IMEI or SIM serial I don't know. I'm sure perhaps each provider uses a set of different methods. I used to be under the impression that a device IMEI that is not recognized by network would get the green light and work, but from what I've read this is not always the case.
My own theory is that if the device in question the tablet that is, has voice capability then it will work without issues with a phone voice and data Sim card.
Appreciate feedback from fellow users .
Sent from my SM-T819Y using Tapatalk
I'm building a test mobile network on some laptops and with a software defined radio based on Open AirInterface (is googleable, but I can't post the link cos I'm a newb) code, and I have this up and running. Additionally, I've bought some programmable SIMs to work with it on a bunch of phones. The information on these I've added into my HSS implementation. The Country Code/Network code deployed on the SIMs is 901/70 - so it doesn't interfere with commercial networks.
I'm testing with a bunch of phones in an isolation chamber, and my end goal is to shift the network into something I have a license for and "go public", but this network will have a low channel bandwidth (3MHz or 1.4MHz in Band 3 LTE). Not many phones have supported this, so I started with a 5MHz channel, which most do support - and I've successfully connected an S4 and a Nexus to my little network. However, when I tried the S6 with a SIM that worked in another phone, it cannot even see the network. I've seen hints of Samsung doing operator whitelisting, but would like to know if this is the case and, if possible, how to add my operator codes into the whitelist.
So far, I've tried the following:
a) "*#0011#" puts you into ServiceMode where you used to be able to enable/disable frequency bands and other such settings with the "Q0000" menu entry - but it looks like Samsung have squished this, also I know the phone has Band 3 operational as I can put a commercial SIM in it that runs on that band. I've not found any way of actually modifying any settings within this mode.
b) I found the file "/system/etc/apns-conf.xml" which contains a list of operator APN addresses - I updated mine to contain my settings, but no joy, and if I "reset to default" my APN settings, my settings are not picked up and I have to manually add my APN (but at least that stays selected)
c) I found some databases in "/data/data/com.android.providers.telephony/databases/", in particular "nwk_info.db" and added my network details to it. The phone then changed from basically saying I was only able to make emergency calls to "Selected mobile network (901/70) unavailable", which kind of at least hints I've moved it in the right direction
The S6 is running a rooted factory reset, and allows SIMS from two different commercial operators on it so it should be completely unlocked. It's never been out of the country, so should have "defeated" the region locks that Sammy put on the phones nowadays (although it begs the question whether rooting the phone resets this and perhaps it's still awaiting 5 mins of calls via a local SIM?).
Does anyone know of a whitelist of MNC/MCC numbers I can add my settings to? Or any other possible solution to this?
The long winded solution is to change the MNC/MCC info on each of my SIMs, but that's a PITA and I'm not even sure it'll work yet (I will attempt to try one soon, but changing the configs on my mobile network is also non-trivial!)
What are they doing that makes them have this ability? They seem to be able turn off things like VoLTE, video calling, and WifI calling but also make it non selectable. For example if VoLTE is not selectable even with the hidden controls from *#*#4636#*#* when a phone is compatible with the network and even previously worked why is that? Does it differ by carrier on how this is accomplished or do they all use basically same methods? Or is it generally all the same thing? I already know they run an IMEI check and have a white list but I’m talking about what happens after that.
Is it the APN settings? I think I also heard there is something called an IMS setting that is sometimes seporate from the APN settings that VoLTE is dependant on and not always visible to the user. I know there is something network side they have control over but from recent experience being told that I do have features like VoLTE enabled on their end unless I am being lied to I think something also is done on the phone itself. Do the network carriers have the ability to just push settings to the phone and can push out improper settings causing such issues? So does that mean they can push over the proper settings or can it only be controlled from the user side? If it can only be controlled from user side then why is it that certain features are forcibly non selectable? It makes no sense if the user side is the only one who has control because this clearly is an indication the network carrier is the one in control.
I have this issue and am just throwing a broad topic before I cover the issue in it’s own dedicated section for my phone model to get a better understanding of what is going on since I know this is by no means device specific as I’ve heard from many different makes and models of similar occuring over different network carriers too. In my specific case it’s Verizon’s network through Straight Talk on an unlocked phone I got through them.
The carrier isn't necessarily remotely enabling or disabling anything. When your device is provisioned, it receives a configuration file that tells it what channels to use, what APN to use, and what features are available. If this configuration file does not indicate the network supports features such as VoLTE, video calling, or wifi calling, these features will not be available. Your device is most likely capable, but you can't use features that don't exist.
Think of it like the cable internet industry - while you might own the modem, the carrier pushes the configuration file that allows it to work on their network. You as the user don't get to decide what that configuration entails, beyond what features your plan supports and what the network is capable of. The only thing you can change are whether you use features that are available. Trying to change the network side configuration is absolutely against the carrier's terms of use, and in most cases is illegal - just like hacking a cable modem or cable TV box to get channels you don't pay for.
It sounds like you need to contact Verizon support and explain that even though your plan and device support VoLTE, video calling, and wifi calling, these features aren't working for you. It's going to be a real pain because they're going to assume something is wrong with your device and try to walk you through the infuriating process of basic troubleshooting, but you'll eventually get some real help.
V0latyle said:
The carrier isn't necessarily remotely enabling or disabling anything. When your device is provisioned, it receives a configuration file that tells it what channels to use, what APN to use, and what features are available. If this configuration file does not indicate the network supports features such as VoLTE, video calling, or wifi calling, these features will not be available. Your device is most likely capable, but you can't use features that don't exist.
Think of it like the cable internet industry - while you might own the modem, the carrier pushes the configuration file that allows it to work on their network. You as the user don't get to decide what that configuration entails, beyond what features your plan supports and what the network is capable of. The only thing you can change are whether you use features that are available. Trying to change the network side configuration is absolutely against the carrier's terms of use, and in most cases is illegal - just like hacking a cable modem or cable TV box to get channels you don't pay for.
It sounds like you need to contact Verizon support and explain that even though your plan and device support VoLTE, video calling, and wifi calling, these features aren't working for you. It's going to be a real pain because they're going to assume something is wrong with your device and try to walk you through the infuriating process of basic troubleshooting, but you'll eventually get some real help.
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These features all were available on same phone and same network before working fine and stopped working a few months before the 3g shutdown and after the shutdown it made it so Im unable to make calls at all since I cant use VoLTE. Im not sure if they had pushed a bad configuration to prepare for this whether intentional or not or if it was result of a bad configuration caused by an Android security update or something. I’ve heard of this happening a lot particularly with unlocked phones on bring your own phone prepaid plans.
Yes, it’s difficult to get ahold of anyone who understands what is going on. I’m not even sure if i can contact Verizon since their support looks like it’s setup where you need a Verizon account for them to assist and my service is through Straight Talk which while its now owned by Verizon I imagine they will give me the runaround because of that small detail and the people at Straight Talk arent high up enough to know some details about the network I would assume as Ive been on the line with them a few times already and their solution came down to get a new phone which I dont want to be pushed into even if it came to a point they start offering it for free since I dont want this to be the case in the future potentially happening over and over. I want them to show they are competent enough to run their own network. The Straight Talk support just keep doing the same things even after getting to higher levels of support, checking my IMEI and ICCID are correct and that they have VoLTE turned on their side in some settings then commonly they work backwards and assume I’m an idiot and ask if I have data turned on.