I have a question about how GSM and CDMA radios work. I have an HTC Merge from USCC (I live in Vermont, USA). They use CDMA and leave the SIM unlocked for prepaid SIM cards. I travel to Alberta, Canada on a regular basis and have access to a post-paid account on Bell Mobility (GSM). I would like to figure out if it is possible to set up my phone to work on both lines at the same time, without having to switch back and forth to check for incoming calls and texts.
Is such a setup possible?
If it is, does anyone know how I would go about getting it set up (perhaps a different thread for the answer to this part)?
On a CDMA phone, where is the carrier information stored (phone number, PRL, etc.)?
The phone is currently rooted, S-OFF, SuperCID, SIM Unlocked, running 2fastrom's USCC Gingerbread ROM.
Radio version is 1.08.00.0804
I am posting this here because I consider it to be first of all a question of whether it is possible to use both systems at the same time, regardless of the phone itself. I have added the phone info in case those who may know the answer need it. If it needs to be moved, I have no problem with that.
Thanks for your time and consideration.
All the best,
Reuben
....
Sent from my HTC Sensation Z710e with Beats Audio using Tapatalk
most phones do not support both cdma and gsm
Sent from my GT-I9000 using Tapatalk
I know the iPhone 4s can use both but it has two separate antennas to accomplish this. I think it comes down to hardware.
Isn't Verizon coming up with some type of solution with VMWare for this? Where you could have two numbers active at the same time, one of them being a business number that was running in VMWare?
Yes, it is partly a matter of hardware - the Merge is set up for both systems. Still not sure if it can "listen" for two different numbers at once. Also curious about whether the phone needs to be listening to both bands at the same time if one number is CDMA based and the other is SIM/GSM based.
Verizon's solution sounds interesting - not sure it is enough to make me switch, particularly if both numbers have to be on their network.
Yes but only if you are not Verizon.
http://www.pcworld.com/businesscenter/article/247646/lg_verizon_and_vmware_demo_virtual_work_phone.html
Currently Telefonica will support 2 simultaneous numbers due to a dual-sim. I really can't wait until entire networks start switching to an all IP based system. This would allow a much more flexible system then the NAM currently used.
Isn't Verizon coming up with some type of solution with VMWare for this? Where you could have two numbers active at the same time, one of them being a business number that was running in VMWare?
Click to expand...
Click to collapse
Dual sim
It will eventually coming , we may see this type of services in near future once iphone will start shipping with GSM and CDMA unlocked version.
No its not doable at the same time
Related
Hi All,
I was wondering if I could use my unlocked 8525 with Verizon's net work if I switched to them? I'm not sure about compatability of the phone with Verizon's voice and data services and was wondering if anyone knew.
Thanks
I dont think so. Att and verizon use two different technologies. Att uses GSM and Verizon uses CDMA. Im almost certain tho a phone that is based on GSM cannot be used on a CDMA network. The phone will work on TMobile or USCellular. They use a GSM based technology. Verizon Sprint and Nextel all use CDMA. If i am wrong and you can use the GSM based phone with Verizon CDMA then someone please correct me. But i am pretty certain you cannot.
OK,thanks. Thats what I thought
Verizon does not have sim cards, is that correct?
mistadj16 said:
Verizon does not have sim cards, is that correct?
Click to expand...
Click to collapse
Not that I've ever seen.
I know sprint phones have sim card slots, but they are not used, at least in the USA.
My guess is that CDMA phones can be used in the same way as GSM phones as far as switching sims to use different carriers, but the CDMA carriers in the 'states don't use that functionality (probably to keep a tighter grip on their sucke....customers and wring more money from them through phone sales/upgrades and extra services, like a data service to put on extra ring tones )
I know that I don't know much about these phones, but what of the setting inside of Settings/Personal/Phone/Band where you can select WCDMA as your network type? I've got an 8525 and it shows as an option, but I just don't know if anyone's tried it before.
CDMA and GSM phones are totally different. The only SIM based verizon phone that Ive seen its the Blackberry 8300 its world edition soo it can bu used through a cdma and also a GSM carrier. I would be interested if anyone knows how to say make a sprint phone capable of being on verizons network. That would be something different.
actually a sprint phone is capable of being used on verison network any cdma phone is. in short the way cdma works the subscriber info is assigned to the phone's esn by the carrier so only the carrier can change your phone with gsm the sim (Subscriber Identity Module) holds the subscriber info and it is assigned to a sim card id not a esn (electronic serial number) so all you have to do to get a sprint phone to work for verizon is get verizon to let it (GOOD LUCK WITH THAT) you would have better luck the other way around verizon is the pickiest co out there when it comes to network integrity and security issues they seem to think that letting people use any phone they want could somehow hurt their network
vn1977 said:
I know that I don't know much about these phones, but what of the setting inside of Settings/Personal/Phone/Band where you can select WCDMA as your network type? I've got an 8525 and it shows as an option, but I just don't know if anyone's tried it before.
Click to expand...
Click to collapse
WCDMA is 3G. 3G on GSM systems is essentially a CDMA standard, but not the same CDMA as Verizon uses. It is not compatible.
-Jay
Does anyone know if an unlocked 8525 will work on Verizons network? I've been using it on Alltel and Verizon bought them out now they want me to get a new phone. Sure hate to give this one up.
If the sim unlock has been run the there should be no reason why not...
Mind you I'm in Australia...
Cheers...
CDMA vs GSM
I went back and forth on this one. (and Welcome!!!!!)
Verizon here in the states is a CDMA (EVDO) system that doesn't use sim cards, GSM systems does. This relates to how your phone communicates on the network. Now willl a GSM phone work on a CDMA network, i think that it will. The SIM card in GSM phones supply the network with your PIM to access the network, it is tied entirely to the network not the phone. CDMA requires action from the carrier, and your access to the network is tied to phone not the network. You deactivate one phone first, then activate the second. You'll probably need to supply your IMEI to verizon and they'll load your access. Just a guess though, cause I've been with cingular/at&t since i carried around backpack sized mobile phones.
Does anyone know better?
As far as I know of, no. I don't believe it has a radio for the CDMA. Although you state you have used it on Alltel which I thought was CDMA...
What reason did they give for wanting you to get a new phone?
I was at at&t and we where unable to activate the phone even though the phone is capable. At&t said everything was good on there end but the phone just wont get a signal but it says it is on at&t.
Does anybody have any ideas how to fix this?
Have u unlocked the sim slot on the phone?
swangotp said:
I was at at&t and we where unable to activate the phone even though the phone is capable. At&t said everything was good on there end but the phone just wont get a signal but it says it is on at&t.
Does anybody have any ideas how to fix this?
Click to expand...
Click to collapse
Quite a few people (including myself) on various boards have acknowledged having this problem as well. I got the SIM unlock code from Verizon but when I do a GSM network scan, nothing is detected. I know it has been escalated above level 2 support at Motorola and hopefully they will address it shortly. Here's another thread about it over on droidforums: http://www.droidforums.net/forum/droid-2-global/96596-droid-2-global-unlock-foreign-sim.html
Yes, I have unlocked the phone from the code verizon gave me.
I hope its a fixable problem. But I noticed when I use an active tmob sim the phone doesnt even say tmobile. But when I use an at&t sim it atleasts says at&t.
I'm very interested (as I'm sure many others are) in a resolution to this. OP did you call VZW global support and let them know you're having this problem? Hopefully the more they hear about it, the faster they'll have a fix
SGMD1 said:
I'm very interested (as I'm sure many others are) in a resolution to this. OP did you call VZW global support and let them know you're having this problem? Hopefully the more they hear about it, the faster they'll have a fix
Click to expand...
Click to collapse
They where no help at all they said it was for foreign sim cards only and that at&t and tmobile where not supported. But they did say verizon was better than both of them combined.
If you feel like experimenting try this:
Go to dialpad, and enter *#*#4636#*#*
Click on Phone Information, and then scroll down to bottom. Set preferred network type from "CDMA auto(PRL)" to "WCDMA preferred" and see if that kicks it on ATT.
I'm 99.9% sure after looking through the user guide that VZW has restricted use of the 850/1900 MHz GSM/UMTS bands, even though the device has the hardware to support them. Most foreign networks use 900/1800 GSM and 2100 UMTS but AT&T/T-Mobile use 850/1900, which is why no one has had any success with them yet.
Hopefully someone can figure out a workaround.
EDIT: Just a US GSM restriction...looks like 850/1900 work abroad: http://www.droidforums.net/forum/dr...d2-global-south-america-first-impression.html
IslesFan said:
If you feel like experimenting try this:
Go to dialpad, and enter *#*#4636#*#*
Click on Phone Information, and then scroll down to bottom. Set preferred network type from "CDMA auto(PRL)" to "WCDMA preferred" and see if that kicks it on ATT.
Click to expand...
Click to collapse
These where the results I got, so clearly it is getting seeing the network. Just not connecting.
Just got off the phone with Motorola and they said the droid 2 global was only for verizon sim cards and when I told them about the unlock code the guy didn't know what they where for. So another dead end. Another theory I have is that the stock verizon rom is blocking at&t so maybe if someone can flash another rom we can see if this is the problem.
Further proof the 850/1900 bands are locked: https://motorola-global-portal.custhelp.com/app/answers/detail/a_id/57058/p/30,6720,7706
"GSM-based global services work only with a SIM card supplied by Verizon Wireless® or by another GSM 900 or GSM 1800 service provider. When you set your phone to use a GSM 900 or GSM 1800 network you may be prompted to enter a subsidy code. To get this code, contact Verizon Wireless."
EDIT: Looks like they're just locked in the US, not abroad: http://www.droidforums.net/forum/dr...d2-global-south-america-first-impression.html
SGMD1 said:
Further proof the 850/1900 bands are locked: https://motorola-global-portal.custhelp.com/app/answers/detail/a_id/57058/p/30,6720,7706
"GSM-based global services work only with a SIM card supplied by Verizon Wireless® or by another GSM 900 or GSM 1800 service provider. When you set your phone to use a GSM 900 or GSM 1800 network you may be prompted to enter a subsidy code. To get this code, contact Verizon Wireless."
Click to expand...
Click to collapse
If this is true why would they say it has the 850 and 1900 bands? I know its not a hardware problem, so if its a software problem there is a chance we can have a workaround. Or the locked bands might be because of the verizon rom.
I was able to put a new rom on my Droid 2 Global and although the rom was working since it was for a droid 2 the radio was not working properly. I was not able to force turn it on. I still have several more things I will try tonight.
swangotp said:
I was able to put a new rom on my Droid 2 Global and although the rom was working since it was for a droid 2 the radio was not working properly. I was not able to force turn it on. I still have several more things I will try tonight.
Click to expand...
Click to collapse
Keep us posted!
This has been done before on Windows Mobile phones (CDMA HTC Touch Pro 2) and requires a radio reflash since the bands are locked in the radio firmware. I am hoping they will develop a solution for Android phones. http://rhodiumw.htc-unlocks.com/
Being that this the 1st CDMA/GSM (Tie if you count Droid Pro) Android device I would wait and see.
firebrain said:
This has been done before on Windows Mobile phones (CDMA HTC Touch Pro 2) and requires a radio reflash since the bands are locked in the radio firmware. I am hoping they will develop a solution for Android phones. http://rhodiumw.htc-unlocks.com/
Being that this the 1st CDMA/GSM (Tie if you count Droid Pro) Android device I would wait and see.
Click to expand...
Click to collapse
Good info, thanks
As from what I learned from previous devices the Droid 2 Global Verizon has a security locked radio. I have seen people unlock the radios from windows mobile phones, it is as easy as installing a .zip file that will unlock the security. I believe it is the same way with the Droid 2 Global. I will try to get this working but I don’t have much knowledge in the development field. But I do know you will have to be rooted. I have also spoke with a friend at Verizon, which claims that they did indeed lock the radios and there is a workaround. He said he was not familiar with this workaround but said it was close to the problem with the windows mobile security locked devices. I am calling this the official reason the phone wont work with US networks. This makes sense, and now that we found the problem it shouldn’t be long before we find a way around it.
Thanks for the info swangotp...that definitely sounds promising. Keep us posted!
subscribing to this thread... I know this is possible.
I'm on the best way, here the facts:
1.) Crossflashing Xoom VZW with the System Image(Tiamat Kernel as boot) of European 3G Xoom is working fine after fastboot -w (complete wipe)
2.) With a firmware upgrade of Atirx 4G CDMA we saw, it is possible to reconfigure MDM6600 for GSM
3.) Simcardslot is working fine with GSM Simcards
Hi all,
Yesterday I got my Xoom. I'm how you see from Austria(Europe), but I ordered it from over the sea because I saw in a teardown, that there is a MDM6600 chip built in.
Now I have it, HSPA is not working, but should only be limited to CDMA by the firmware.
I would like to change that.
My first idea is, to search for MDM6600 driver sources, compile them for the tegra and replace the existing... but this expect, that the limitation is in the libril and not in the kernel...
Any thoughts to this topic?
edit: stupid me, first of all would be nice to take a look at etc
someone has an idea what the location.cfg is, and what the flag DL_LCS_NETWORK_3GPP (set to 0) are doing?
Kind Regards
Ralph
Click to expand...
Click to collapse
I have no idea how to help but I sure would like to. If there is anything I can do let me know I'm all set up to do all kinds of stuff I just would not know where to begin.
Sent from my Xoom using XDA App
Just 'cause the chip does both modulation schemes doesn't mean the appropriate antenna-interface hardware is built into the device. They put a 6600 in there 'cause they fully expected to push out a GSM version; I'd just wait for that one.
concerning the antennas(from www.motorola.com):
CDMA 800 /1900 LTE 700, Rx diversity in all bands
would be a bit funny, to use a multiband chip, to need not to produce different devices, but differ by the antennas
regards
Not to mention the fact that there is a place to stick a sim card in no the top of the device
Sim card slot is for the lte upgrade...
The SIM card is for LTE in the States, but again- just 'cause the chip is in there doesn't mean the US-spec Xoom has the requisite hardware (not to mention the proprietary Qualcomm modem SW) to let it run on GSM in the versions shipped in the states.
When we make GSM handsets at my clients, we even have to make separate hardware for the I, II, V-banded stuff (AT&T) vs. the I, II, IV-banded stuff (T-Mobile), and that's all with the same chipset.
You are going to need to take a good look at the NVM and amss.mbn(radio baseband image) in order to make this work.
Have you used RadioComm to read and dump the NVM?
That would be an excellent place to start. Unless of course, you had access to MDM6600 GSM radio images and source code...
I don't have even the slightest knowledge necessary to be able to contribute to this conversation but I do know that I am planning to go out the country for quite a while and would love to be able to connect to a wireless data service of any kind. I will be in a country with cdma also but of course it is not verizons.
If what you are trying to do works I would happily try to donate something out of appreciation. The idea of my xoom working with gsm networks would be more than a dream come true. I wish you all the best. Let me know if there is anything I can do (I know there isn't though, I really dont know the first thing about modding other than that the modders are awesome!)
Sent from my Xoom using XDA Premium App
Good Morning,
There is something confusing me, and it seems I've to think about something I cannot imagine actually.
So my big stupid question:
Do you need a simcard to connect to verizon's cdma network?
And if not, how are you athentificating in the net?
Regards
Ralph
CDMA authenticates to its network via the combination of the MEID (formerly known as "ESN") and the MIN, both of which are hardwired into the firmware of the device.
Ok, so the device is authentificating, but from where do the network know that you are user xyz? In gsm networks because of the simcard id, and in cdma nets?
Sent from my Xoom using XDA App
They associate the MEID/MID/MIN to your account.
For example, they scanned the barcode from my Xoom when I bought it and added it to the Verizon account they had already finished setting up for me. Once I got it home and hit the "Activate Device" button, the device got on the VZ network, where the setup information (the phone number, PRL, etc.) got downloaded to the CDMA 3G radio. But all that happened 'cause the VZ servers were already set up to associate that MEID to me beforehand.
ouch, that means there is a massive firmwaremod needed so that it can use the simcardslot for auth...
ok, please tell me what you know about how transfering the data from the sim to the chip works (bookmarks and so on)
do the ril-daemon play a role?
thanks
ralph
GhostOfTheNet said:
Good Morning,
There is something confusing me, and it seems I've to think about something I cannot imagine actually.
So my big stupid question:
Do you need a simcard to connect to verizon's cdma network?
And if not, how are you athentificating in the net?
Regards
Ralph
Click to expand...
Click to collapse
Now no sim card is used to connect to Verizon's 3G network. The new 4G Lte network will use a sim card, but that has yet to be activated. At present you connect to Verizon's 3g network through the cdma radio which needs to be registered and then activated by them, but it does not use a sim card.
Sent from my Xoom using XDA Premium App
The sim card slot is a dummy slot right now, there are no electronics in there that can even read a sim card right now. When you send out the Xoom for the LTE upgrade they will put a real modem in there with the sim card slot. It is PHYSICALLY IMPOSSIBLE to convert the Verizon Xoom to GSM at this point in time.
post to delete
chaoscentral said:
The sim card slot is a dummy slot right now, there are no electronics in there that can even read a sim card right now. When you send out the Xoom for the LTE upgrade they will put a real modem in there with the sim card slot. It is PHYSICALLY IMPOSSIBLE to convert the Verizon Xoom to GSM at this point in time.
Click to expand...
Click to collapse
Key words: "...at this point in time."
That may change once the hardware is in place for the SIM slot it MAY be possible to build a radio image that can access GSM/HSPA bands.
Not easy, but not impossible.
cellzealot said:
Key words: "...at this point in time."
That may change once the hardware is in place for the SIM slot it MAY be possible to build a radio image that can access GSM/HSPA bands.
Not easy, but not impossible.
Click to expand...
Click to collapse
You would also need to modify the antenna to pick up the correct frequencies, they usually aren't on the same band as CDMA. For example VZW is the only carrier going for a total 700mhz 4G network.
chaoscentral said:
The sim card slot is a dummy slot right now, there are no electronics in there that can even read a sim card right now. When you send out the Xoom for the LTE upgrade they will put a real modem in there with the sim card slot.
Click to expand...
Click to collapse
That's almost correct. There's a working, active SIM-card slot that's hooked up to a serial port on the CPU; reading a SIM card right now would just be a matter of some (extra?) software. What's physically missing is the actual LTE modem, and there's a dummy card in the mini-PCI slot right now.
But that's not why it's not possible to turn the current device into GSM; as noted in this thread before, there's a lot of other things that'd need to be there, and just 'cause the 6600 is GSM-capable doesn't mean it's a simple, software-only modification. Even if it were, good luck getting the customized baseband software from QCT for it.
I would like to hear your advice about testing multiple carriers on my nexus phone. Currently i'm on T-mobile prepaid, but i would like to begin testing other carriers to see which one does better in my area.
Just a few questions i have:
- Do you keep your same telephone number though all the carriers (is this even possible) or do you have different numbers for each carrier you are testing?
- Is this as simple as swapping between sims?
- Do i need to reset my APN everytime i swap between sims?
mclain1 said:
I would like to hear your advice about testing multiple carriers on my nexus phone. Currently i'm on T-mobile prepaid, but i would like to begin testing other carriers to see which one does better in my area.
Just a few questions i have:
- Do you keep your same telephone number though all the carriers (is this even possible) or do you have different numbers for each carrier you are testing?
- Is this as simple as swapping between sims?
- Do i need to reset my APN everytime i swap between sims?
Click to expand...
Click to collapse
I am planning to test multiple carriers as well. For the phone # I recommend you get Google Voice. With Voice you can use any # and have the calls/texts forward to G Voice. The only issue is MMS which do not work. I have 3 phones at present and they all ring when a call comes in using Google Voice. This is far simpler than trying to port a single phone # through multiple carriers.
I am presently testing the AT&T version of StraightTalk. Will get a T-Mo ST Sim next month and try it out. Then will try a regular TMo plan. The process is the same as the original set-up. Add the Sim, start the service and change the APN (have to change each time as this is how the data gets routed).
Sent from my Nexus 4 using xda premium
swest6602 said:
I am planning to test multiple carriers as well. For the phone # I recommend you get Google Voice. With Voice you can use any # and have the calls/texts forward to G Voice. The only issue is MMS which do not work. I have 3 phones at present and they all ring when a call comes in using Google Voice. This is far simpler than trying to port a single phone # through multiple carriers.
I am presently testing the AT&T version of StraightTalk. Will get a T-Mo ST Sim next month and try it out. Then will try a regular TMo plan. The process is the same as the original set-up. Add the Sim, start the service and change the APN (have to change each time as this is how the data gets routed).
Sent from my Nexus 4 using xda premium
Click to expand...
Click to collapse
Ah very nice informative post thank you...!
2 questions for ya..
- Is there a difference between T-Mo prepaid service vs their regular plan as far as coverage/performance..?
- How would one know what information to change too in the APN. Is it pre-programmed on the SIM card and just load default settings on the phone?
You're choices are basically Tmo or ATT, yeah some of the MVNOs have lesser coverage but there isn't much "testing" to do IMO.
- As for phone number, port to google voice and you never have to worry about your number again.
- All you have to do is swap sims.
- You don't have to reset APNs but you will have to either switch APNs or add a new APN, the data is a google search away.
- There is "supposedly" a small difference between tmo pre and post paid, I find it hard to believe but the only way to test (going out all over the country to map out coverage) I'm certainly not willing to do and I wouldn't trust the maps to be accurate.
- Do a search the info is available.