Instant Answers/Community Forums/Bring Your Own Device (BYOD)

BYOD and LTE

Ken Kinder
posted this on June 25, 2012 18:48

So I heard that while Verizon LTE devices have SIM cards (yay!), Sprint's new LTE devices do not have SIM cards. I'm wondering where this leaves the prospect of GSM-style bring-your-own-device policies on LTE networks like, in the future, Ting?

Will you be able to use an unlocked LTE device with a SIM card?

 

Comments

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John Lafitte

I don't think Verizon devices have sim cards for their network, only the "world phones" that roam globally on GSM... which btw, sprint devices also require, LTE or not.

August 10, 2012 12:43
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John Lafitte

er... I probably spoke too soon... I googled and their LTE devices do use SIM, but is it possible that is for global LTE roaming?

August 10, 2012 12:45
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Dale Williams

CDMA SIM cards do exist that allow users to switch phones.  I'm too lazy to try and sift through anything Big Red is up to to find out what kind of card their LTE devices will use, though.

http://en.wikipedia.org/wiki/CSIM

August 10, 2012 13:11
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John Lafitte

Well just because a spec exists doesn't mean anyone is using it... at least not anyone in the US.  I think the SIM card that Verizon uses is ONLY for LTE, not CDMA.

August 10, 2012 13:13
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Ken Kinder
Ting Army

So I'm asking a friend of mine who works for a major 3G/4G CPU company that shall not be named for clarification. He programs some of this stuff, so hopefully he'll know more about actually authenticating an LTE phone.

 

But here's the deal. GSM is the international standard, and it has always used SIM cards. CDMA, which Sprint (and therefor Ting) use does not use a SIM card. Devices are not portable.

LTE is based on GSM -- it's basically the next version of GSM and because of that, all LTE devices do have SIM cards. An LTE SIM card shouldn't just be for international roaming, it should be for switching LTE carriers on an unlocked device. Of course, since any Sprint/Ting (or Verizon) device would also have a CDMA radio, interchangeability isn't really possible now. In order for universal unlocked LTE to work, everyone would need to switch to 100% LTE and upgrade their radios to use all spectrum ranges (carriers use different frequences).

Still, Verizon is shipping its LTE devices with SIM cards, and while that might not facilitate BYOD to and from Verizon just yet, it does let you change devices without calling Verizon for a permission slip.

Sprint is in the habit of forcing people to sign two year leases even if they're just switching phones they completely own:

http://consumerist.com/2012/08/bring-your-own-phone-sprint-still-wants-a-contract.html

Perhaps for that reason, Sprint is using "embedded" SIM cards. In order to meet the LTE standard, there must be a SIM card, but by "embedding" (read soldering) their cards inside the phone where you can't get to them or remove them, Sprint is bringing the lockin of CDMA in to its LTE era, which is sad.

So to recap:

  • LTE does use SIM cards.
  • CDMA does not.
  • Sprint is subverting the portability of LTE by "embedding" their LTE SIM cards.

So that leaves me wondering, if I overwrite the ESN on a Sprint device to bring it to Ting, what about the embedded SIM card?

Not sure.

August 10, 2012 13:20
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Ken Kinder
Ting Army

@Dale: What I'm wondering is, if I change the ESN of a CDMA Galaxy Nexus, is there a separate ESN inside the embedded SIM card for LTE?

That much isn't clear to me.

August 10, 2012 13:24
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John Lafitte

Yeah not sure either.  I'm of the mind to just buy my device from Ting until we can have proper BYOD.

August 10, 2012 13:24
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Ken Kinder
Ting Army

Yeah, me too. I got a screaming deal on a Sprint Galaxy Nexus, and while I'd prefer a stock Android device, I'm going to get an S3. After learning that LTE was uncertain, I don't want to risk it.

I figure it's easier to hack the Galaxy S3 into having an AOSP-based ROM than it is hack a Galaxy Nexus into working with LTE.

August 10, 2012 13:28
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Dale Williams

This answers the original question definitively.  You can BYOD on Verizon's LTE network by swapping the SIM.

http://support.verizonwireless.com/faqs/VZAccess/4g_sim_card.html

Can I use my Verizon Wireless 4G SIM card in a 4G LTE device not purchased from Verizon Wireless?

Yes. You may activate any 4G LTE device that has been certified by Verizon Wireless to be compatible with our 4G LTE network, including devices not purchased directly from Verizon Wireless. Simply activate your 4G SIM card on a Verizon Wireless price plan.

August 10, 2012 13:46
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Dale Williams

I can't tell if the 4G sims in Verizon's phone are exclusively LTE or if they're generation agnostic for a fact, but there is no mention that you'd have to do anything special after swapping the sim to get full service.

August 10, 2012 13:52
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Ben Lucier
Ting

Hey folks, 

@Ken Kinder wrote a pretty good recap. We can also confirm that Sprint LTE devices will be shipped with non-removable SIMs.

Ken: Not sure how hacking these devices will work yet... 

August 10, 2012 14:09
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Dale Williams

@Ken: The wording on the FAQ leads me to believe that at least some (if not all) of your identity is contained on the 4G SIM (Because you can sim swap to a new phone and automatically get LTE service).  GSM SIM cards are not easily reprogrammable and use secret keys and such to prevent cloning.  Unless these new SIMs (embedded or not) are less secure, the only way I can see getting full compatibility would be to open the device, remove the embedded sim, and solder a new one in place.

The S3 is much loved by the hacker community.  I think you'll have a lot of AOSP roms to choose from there.  ;)

August 10, 2012 14:49
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Ken Kinder
Ting Army

@Ben: Thanks. I'd live to experiment hacking my Galaxy Nexus, but since LTE isn't even in Denver yet, I don't think I would have any new information.

@Dale: Yeah, it does seem that way. Though FWIW, SIM cloning is pretty easy to do and Sprint's CDMA phones were designed to prevent reassigning the ESN, but that turned out to be pretty simple after all.

August 10, 2012 15:25
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Zarthan South
Ting Army

Although not new the HTC Design 4g Motorola Photon are World Phones (GSM) with replaceable SIMs. 

November 28, 2012 12:17
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Drew SR

I would just like to know why Sprint isn't allowing BYOSD and LTE phones at this time.  I hope that someone at Ting can answer this question.  There must have been a discussion somewhere along the line where Sprint said no for one reason or the other.

November 28, 2012 12:45
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Scott Allan
Ting Help Center

I would imagine we will see this restriction lift early next year. They want to protect iconic devices for a period of time from launch. Hope that helps!

November 28, 2012 12:48
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John Lafitte

Well it's worked so greatly for them so far...  They are a distant number 3 right now, aren't they?

November 28, 2012 12:50
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Drew SR

Scott, thanks for the answer, I had a feeling that was the issue.

But it still sort of doesn't make sense since we can buy LTE devices from Ting and use them on Sprint.

I think that Sprint should be more concerned about getting more customers any way that they can, be it through MVNO's or through them directly.

November 28, 2012 13:18
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Zarthan South
Ting Army

Just a guess but LTE phones have only been available for about a year. For Sprint, BYOD for LTE devices could/would mean loosing an existing customer on an active contract. 

November 28, 2012 13:30
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Scott Allan
Ting Help Center

Zarthan is correct in that the vast majority of Sprint Retail LTE devices will be under contract / subsidy restrictions. BYOSD is a bold step in itself, and it makes some sense that there are limitations initially. This is a very new program, and once it is proven to work well I expect we will see less restrictions.

November 28, 2012 23:38