Ok, so i was explaining to my lil sister about sim cards, and as i was saying how only Verizon worldphones had sims, i realized that you could, in theory, put a Verizon 4g sim into a 3g worldphone, and.... what would it do? I'm a little hazy on how exactly Sim cards work, but would it be possible to artificially "create" a 4g phone using a 4g Verizon sim?
EDIT: ok, since there are no answers, i realize this is a noobish question, but does the sim card contain the actual 3g/4g/whatever radios, or does it just "enable" them?
The sim card contains the customer account information, so once you lock the signal verizon knows how to properly bill you for your usage.
4G sim cards are different than 3G sim cards although they are in the same format. You can't just swap your Droid 2 Global Sim card and expect to work in your Droid 3 or vice versa becuase the ESN is what is tied to your number, the sim card is just there for roaming purposes (i may be wrong on that one), but i know that even on the global phones, you must have the sim card inserted in the phone to be able to get service with verizon.
The 4G sim card works more like a REAL (GSM) simcard you can swap your sim card into another 4G device and your number will transfer.
Here is another difference, the same sim card on global devices can be reused like you can go to your account and transfer your phone to another account without the need for another sim card. The 4G sim cards become invalid once they are deactivated and you will require a new blank sim card in case you want to activate your phone number again (this usually happens when you switch from a 4G device to a 3G, then move back up to a 4G device), they work much like most GSM sim cards work.
So in sumary, the 4G sim cards works more like a real sim card.
Hello folks,
I have a question here as I bought op2 for my friend who was carrying two phones always so once I saw this phone liked it and bought it it has arrived and I have already upgraded the firmware on this (it is a Canadian version).
No we face this issue that his both Sim cards are from telus and when I put those cards in the op2 phone only one Sim card work at a time second card won't even register to the network I done couple of reboots and turn off and on card 1 and card 2 but result is same it works with one Sim at a time can any one help me here I will be great full thanks in advance.
Regards,
fuzzuy said:
Hello folks,
I have a question here as I bought op2 for my friend who was carrying two phones always so once I saw this phone liked it and bought it it has arrived and I have already upgraded the firmware on this (it is a Canadian version).
No we face this issue that his both Sim cards are from telus and when I put those cards in the op2 phone only one Sim card work at a time second card won't even register to the network I done couple of reboots and turn off and on card 1 and card 2 but result is same it works with one Sim at a time can any one help me here I will be great full thanks in advance.
Regards,
Click to expand...
Click to collapse
From what I can see on http://www.telus.com/en/bc/mobility/network/coverage-map.jsp Telus doen't operate a 2G network. The sim that is not using data uses only 2G network, and there is the problem for you
I use two sim from same carrier and no issues, my carrier support 2g/3g/lte, sim with data on is 3g/lte and sim without data always fall to slowest network
If your carrier only support 3g you won't be able to use two sims.
Sent from my ONE A2005 using Tapatalk
Hi all,
I have the dual sim S7 SM-G935FD running the XSP firmware. Rooted with the microSD Mod on Sim 2. It's being used in the USA at the moment. Sim 1 is AT&T and Sim 2 is T-Mobile. Both are USA sim cards. Everything goes through Sim 1 AT&T - Voice, Text and Data. Sim 2 is just for receiving calls only. Sim 1 is set at LTE/3G/2G and Sim 2 is 2G only.
Since day one I have this connectivity issue pertaining to data connection.
When Sim 2 gets a weak signal and eventually drops out, data connection on Sim 1 remains - everything works. However, when Sim 2 is picking up signal again, the data connection on Sim 1 drops out.
When this happens, the pull down notification will display that the data connection is on Sim 2 - as if the phone switches the data connection from Sim 1 to Sim 2 by itself. However, if I go to the Sim Manager, it will show that the data connection is still on Sim 1 like it originally was. At this point, the phone has no data. And yes, the phone is displaying conflicting information. Notification says Data is on Sim 2 but Sim Manager says Data is on Sim 1.
To fix this, I have to use the Sim Manager, select Sim 2 for Data. Wait a few minutes. Then, choose Sim 1 for Data again, then everything comes back normal. Data connects.
This is quite annoying in a poor reception area.
Troubleshooting steps that I have tried but they do not fix the problem-
Flash stock firmware no root
Use a different stock firmware - XEU
2 sim cards only with no microSD card on the back of Sim 2
Choose 3G/2G only for Sim 1 and 2G for Sim 2
Swapping Sim 1 and Sim 2
If I disable Sim 2 the problem goes away, but of course, what's the point of dual sim then?
I also have a S6 Edge+ Duos SM-G9287 but it does not have this problem.
Any ideas? Thanks.
Just wanted to add that I am experiencing this as well.
Man this is getting unbearable. Is there a specific forum for the FD devices? I'm thinking I might just return this phone while I still can.
Wow I was going to put something on boards as well with literally the exact same setup in USA. It gets way annoying when tmobile gets weak and switches even though I have it set on sim 1 data. I really hope there is a fix or else I might make the switch to htc10 (if they even get a dual sim) and keep my fingers crossed it works better. My S6 duos works better than this but I don't have additional memory with hybrid SD sim card on s7.
Sent from my SM-G935F using XDA-Developers mobile app
FYI -
I have been running XSG firmware. I just upgraded from APC8 to APD1 and the problem still remains.
Just trying to save some time for those of you who thinks upgrading will resolve the issue... it will not.
It is amazing how the S6 Edge+ Duos does not have this problem. Things went backwards for Samsung.
No problems here though mine is the G9250 dual sim version (HK).
G9250 is s6 edge is it not? We are on g935FD. It seems like I can never find the elusive perfect dual sim! Always some kind of bug! Might be heading back to my Xperia z5 premium. Can you guys confirm that it's wifi causing it? Seems like whenever I come off of a wifi network it never picks mobile data back up.
That seems like part of the problem too..as soon as wifi loses connection then it switches and then no more data
Sent from my SM-G935F using XDA-Developers mobile app
Has anyone fixed this? I have tried to flash a couple different modem firmwares to no avail. The T-mobile one won't flash as it uses a snapdragon chipset.
Mine was doing fine until I did a firmware update and now the data connection problem appeared. I was on a B6 firmware with a B9 modem on a AFG CSC so I will try to go back to this and report back whether the issue resolves. Any firmware starting D1 (tried D3, D6 and D8) causes the data connection lost issue. Even just going back to a B9 modem with the D8 firmware didn't help. What a pain in the rear...
Follow up to my previous post:
Officially, G935FD is a piece of crap. Tried every combination of modem/AP to get this work but no luck. Resorted to single sim mode for now.
I have this same issue. the only way it works is to manually select one sim in use at a time. I just removed the second sim and added a micro sd card for now.
craigg1 said:
I have this same issue. the only way it works is to manually select one sim in use at a time. I just removed the second sim and added a micro sd card for now.
Click to expand...
Click to collapse
Did you update your firmware to a different CSC? That's when my issues started (went from AFG to BTU and even after going back the problem wasn't fixed)
What is your original CSC?
onurd said:
Did you update your firmware to a different CSC? That's when my issues started (went from AFG to BTU and even after going back the problem wasn't fixed)
What is your original CSC?
Click to expand...
Click to collapse
Mine didn't work out of the box with stock firmware. I have since upgraded the stock firmware but haven't tried using two SIMs with the latest update. Maybe I'll test it over the weekend.
+1 on this bug existing for me since day one. I have been sticking it out and staying with dual sim as I don't have any other option. Kinda wishing I had just returned it... I have gone through hell trying to talk with people in India (where the phone is apparently from) about just getting the bug's existence up the chain. If only we could get a dev to take a look at our logs so I can have a reason to just root the damn thing already. Has anyone tried maybe flashing the sim manager apk from the s6 edge? Is there even a sim manager apk?
I have exact same problem with S6 edge+ dual sims. SM-G9287. Problem started since marshmallow updated. Didn't have this problem before under old android version. Has anybody found any fix yet? Right now, If I disable one of the sim, then it seems ok, but I need both sim to be on to receive call on either number.
My phone was stock firmware. Problem seems to be with Marshmallow 6.0.1 , not because of custom firmware.
vietmax said:
I have exact same problem with S6 edge+ dual sims. SM-G9287. Problem started since marshmallow updated. Didn't have this problem before under old android version. Has anybody found any fix yet? Right now, If I disable one of the sim, then it seems ok, but I need both sim to be on to receive call on either number.
My phone was stock firmware. Problem seems to be with Marshmallow 6.0.1 , not because of custom firmware.
Click to expand...
Click to collapse
Kind of same problem here, but it happens only since I received the update to APD1.
I live on a border zone, so I have to force my LTE sim card to its own network. The second SIM is only on 2G.
When the phone loses its own network, SIM with LTE completely disappears, everything is moved to SIM 2G and of course I lose network. The problem is that the SIM with LTE is not seen anymore, even if I go back where the signal is, and the "mobile networks" option disappears in the Settings. I cannot do anything else the reboot the phone to see the SIM again.
Ciao Marina
I have similar issues with my s7 duos not the edge model. Sim1 tmobile, sim2 at&t. Sim2 seems to be the issue for me. Cell quality at my house is not great. I also have a xperia z5 premium dual that has similar problems mainly with lte. The samsung does hold lte signal but the bars are misleading. But the samsung, I woke up this morning and sim2 was offline no calls or text or data. Call quality with sim2 isnt as good either. I blame cell signal on that since the sony has similar issues. But I have seen it with sim1 set to calls and texts and sim2 for data the pull down says sim1 even though sim manager says sim2 is data. Wtf right? Disabling sim2 and reenabling gets it back working again but what happens when the phone does this is you lose data since sim1 data would be gsm only. The common theme is sim2? Also seems signal quality is a big factor. My CSC code is ECT which is Nigeria. I have not changed firmware yet other than the APD1 update. Ironically my xperia z5 dual didnt have these issues at all with lollipop the problems started with marshmallow. I am in the US by the way.
Temporary fix?
Looks like I accidentally ran into a temporary fix, that's working for me for the last few days. I'm on Vodafone for SIM1 and T-Mobile for SIM2, EU&US.
When I restart the phone and set SIM1 for data on LTE/3G/2G it connects, but looses the connection after a while and defaults to SIM2 (with no data). No BT, no WIFI, no data icon anywhere the screen.
When this happened, I ejected the SIM card holder and pushed it back in 2 seconds. Suddenly SIM1 was trying again to connect and the 4G icon appeared. At his point I turned on WIFI.
The weird stage: WIFI on, 4G icon flashing every 5secs – but it's working as it should. If I loose reception, it does not switch cards. Actually never switches card if I don't want to. I can live with the flashing 4G until we have an official fix.
Let me know if it works for you guys!
Im learning that mine is a lot more stable if I set everything to the same sim and not split up talk/text on sim1 and data only on sim2 like I was doing. Not sure if this is placebo for now but I have everything set to sim2 and so far so good with no drops.
Hi All!
I own a Lenovo K6 Power as you can already tell,
in which the Data functions were working without any issues.
A few months back I started using 2 sims instead of 1. Since one carrier had faster internet and better connectivity than the 1st.
Still using the 1st SIM for calling and 2nd SIM for data. Occasionally I would switch to the 1st SIM for data when my data pack was over for the 2nd SIM etc...
So one fine day, I was switching back to SIM 2 (Sim I use for data) (Normally when you switch SIMs both deactivate and reactivate with new settings ie SIM 2 for Data).
So while this was happening like usual it took a few seconds to switch SIMs in the midst of this I suddenly got a call...
Which I was unable to answer till the buffering animation left my screen.
When that did get over... Both my SIMS were set to EDGE 2.5 g when they were always recognised as HSPA 3G and 4G LTE for SIM 1 and SIM 2 respectively.
Now I am unable to attain the speeds I used to, it is just barely usable now...
I then tried the usual troubleshooting (Airplane Mode on/off, Deactivating / Reactivating SIMs, Swapping SIMs physically from their slots and Finally Rebooting...)
Now when I recently tried doing the same my 2nd SIM which I usually use for Data appears as SIM Card Not Ready...
However, when I individually insert SIM 2 it is read by the phone
But still, whether I individually insert the SIMs or together the phone recognises both the SIM cards as 2.5g EDGE.
They used to be HSPA 3G and 4G LTE.
But now I can't use Data on my phone which is the major problem...
Please Help
Reset ur phone.
Is there any other option?
Apart from this...
I don't want to lose my data.....
What if that doesn't solve the problem...
I have been using Mi A1 using one SIM card for a couple of months without any problems. Always stock ROM. And now after I put another SIM card, both cards worked OK for 2 days, but then both stopped working. It happened overnight: the phone was not used, just lied on a shelf and in the morining it was offline. This is not just about the Internet, I cannot make phone calls.
What I tried:
removing one SIM card
swapping for a differend card
changing network mode to 3G and 2G
factory reset
flashing an older official ROM.
None of these helped. The phone recongises SIM cards, network operators, but cannot register with them any more. Signal strength remains at zero.
Is there anything else I can try? Is it a hardware issue? I got this phone on AliExpress last year. They give only 6 month warranty.