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EVO LTE on CM10 nightlies - LTE Data session issue


aparish21

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I have just recently got both the CM10 rom on my device along with LTE coverage near me and have an odd issue. I generally have wifi coverage so data isn't a problem, but I noticed once I picked up LTE coverage, if I turn off my wifi, my device says it is still connected to LTE but cannot establish a data session. even if i cycle though connection settings, reboot, etc....

 

Anyone else seeing this or similar issues

 

 

Also, is there anyway to update PRL on a mod?

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What I would do is backup the current ROM you are using. Then flash a stock rooted ROM back to your device, to see if its still having the same issue. Right now I'm running Decks CM10 and since LTE is sparse right now I'm wondering how we know if LTE is working on these custom ROMs the way it should..

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What PRL are you running and what is your need to change it?

PRL is 25006, the need to change was to see if another version would change result...

 

I somehow jinked up my nandroid of stock ICS and the phone won't boot to it. I ended up factory resetting and the re-flashing the CM rom I had on it (CM10 nightly 10_03) and that seems to have resolved for the moment. I am able to get a data session on LTE now, or at least the device says I do... speeds are avg 3-6 DL and 2UL so whatever connection I have isn't great. -108dBm on LTE

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Glad I read this because i was gonna start another post. Over the weekend I went to a site that was know to have NV upgrades done. I origianlly was going to flash back to a stock ROM but didnt have enough time. All day while there I could see that I had eHRPD but my data was totally jacked up the network state either reading disconnecting or disconnected. I didn't know this though until I got home later in the day and looked at my screenshots. What made this more frustrating is that at some point all towers I came across that day went eHRPD and I was trying to connect tyo veriy. This was all on Saturday.

 

That night I flashed by to a rooted stock Sense ROM to test again. This time no issues at all connected to eHRPD pretty easily, at night it seems to want to stay in 1x but that may be something else. This morning on the drive never disconnected and my data was fine. The problem with the CM10 and likely any AOSP ROM is that LTE is not saturated enough for devs to know it if works correctly.

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CM10 has an issue with the radio interface layer and will not connect to ehrpd for any sustainable amount of time. Lte works, but it is worse than a sense rom when it comes to connecting to it. I've been lurking around the irc channel and it seems like that's what they are concentrating on fixing. Even if they fix the bugs it's not going to connect to lte any faster until htc fixes the radios on our phones. I'm starting to believe that no threshold issue exists and the radio programming is horrible and doesn't know that lte is available.

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Apparently there is an issue with LTE -> eHRPD handoff associated with Qualcomm chips. I've heard this is due to how Sprint handles LTE authentication and that the issue isn't happening on VZW devices. The OEMs have come up with temp fixes which is why LTE seems to work better on stock roms but isn't up to par on AOSP builds.

 

This is also happening on the Sprint Samsung GS3.

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Apparently there is an issue with LTE -> eHRPD handoff associated with Qualcomm chips. I've heard this is due to how Sprint handles LTE authentication and that the issue isn't happening on VZW devices. The OEMs have come up with temp fixes which is why LTE seems to work better on stock roms but isn't up to par on AOSP builds.

 

This is also happening on the Sprint Samsung GS3.

 

Interesting. Can you explain more about how Sprint authentication works? Does this problem also affect the acquisition of LTE signal in the first place or after losing it? Does the OEM workaround involve the mysterious "LTE available" files we have been viewing through the hidden menus on both handsets?

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Interesting. Can you explain more about how Sprint authentication works? Does this problem also affect the acquisition of LTE signal in the first place or after losing it? Does the OEM workaround involve the mysterious "LTE available" files we have been viewing through the hidden menus on both handsets?

 

I believe those are used for scanning. Basically the phone remembers where LTE was. HTC didn't implement theirs correctly for some reason.

 

 

Sent from my C64 w/Epyx FastLoad cartridge

 

 

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I believe those are used for scanning. Basically the phone remembers where LTE was. HTC didn't implement theirs correctly for some reason.

 

 

Sent from my C64 w/Epyx FastLoad cartridge

 

But we know that the list in the "LTE_available" file is not a list of LTE towers.

 

And as far as the GS3 goes, it does not function perfectly, either. By all reports it outperforms the EVO 4G LTE in holding and/or acquiring an LTE signal. But as someome who has used a GS3 extensively for 4G testing, there also are many times when it will fail to make an LTE conneciton without toggling.

 

So if the root cause of all this is some general weakness in Sprint's authentication scheme, and autoprime knows more detail about this, I would like to hear it and where the information comes from.

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But we know that the list in the "LTE_available" file is not a list of LTE towers.

 

And as far as the GS3 goes, it does not function perfectly, either. By all reports it outperforms the EVO 4G LTE in holding and/or acquiring an LTE signal. But as someome who has used a GS3 extensively for 4G testing, there also are many times when it will fail to make an LTE conneciton without toggling.

 

So if the root cause of all this is some general weakness in Sprint's authentication scheme, and autoprime knows more detail about this, I would like to hear it and where the information comes from.

 

Correct, it is a list of 1x sectors as LTE doesn't use a SID. Just like Evdo doesn't.

 

Sent from my C64 w/Epyx FastLoad cartridge

 

 

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But we know that the list in the "LTE_available" file is not a list of LTE towers.

 

And as far as the GS3 goes, it does not function perfectly, either. By all reports it outperforms the EVO 4G LTE in holding and/or acquiring an LTE signal. But as someome who has used a GS3 extensively for 4G testing, there also are many times when it will fail to make an LTE conneciton without toggling.

 

So if the root cause of all this is some general weakness in Sprint's authentication scheme, and autoprime knows more detail about this, I would like to hear it and where the information comes from.

 

To be 100% honest, I am not sure of what the exact issue is with the LTE auth. The info I'm relaying comes from a friend on a dev team who works with both devices. I was told that Verizon isn't having these issues but Sprint has a "different setup".. and that there will be LTE connection issues.

 

This topic was only lightly discussed as it came up during another LTE discussion. I had assumed it was due to Sprint still relying on CDMA.. where as Verizon is using a more "standard" WCDMA/LTE setup on their LTE devices. This is just my guess.. and I do not know the true reason for this issue.

 

Adding a little more info... I was told this is something Qualcomm knows about and does not care to fix. So that tells me that the reason something "isn't working" is due to a non-standard setup.. so obviously thats not something Qcom wants to go out of their way to fix. But again.. that's just more guessing from me.

 

The only thing I had hoped to achieve in my original post in this thread was to let others know that Qualcomm, OEMs, carriers and XDA Devs are aware of this issue. How it will be handled is anyones guess. I'm just hoping the CM team finds a "fix" to make LTE/eHRPD a little more usable on AOSP roms. Sorry for the lack of advanced detail.. I know we all like that stuff. Of course, if I hear anything else I will update.

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To be 100% honest, I am not sure of what the exact issue is with the LTE auth. The info I'm relaying comes from a friend on a dev team who works with both devices. I was told that Verizon isn't having these issues but Sprint has a "different setup".. and that there will be LTE connection issues.

 

This topic was only lightly discussed as it came up during another LTE discussion. I had assumed it was due to Sprint still relying on CDMA.. where as Verizon is using a more "standard" WCDMA/LTE setup on their LTE devices. This is just my guess.. and I do not know the true reason for this issue.

 

Adding a little more info... I was told this is something Qualcomm knows about and does not care to fix. So that tells me that the reason something "isn't working" is due to a non-standard setup.. so obviously thats not something Qcom wants to go out of their way to fix. But again.. that's just more guessing from me.

 

The only thing I had hoped to achieve in my original post in this thread was to let others know that Qualcomm, OEMs, carriers and XDA Devs are aware of this issue. How it will be handled is anyones guess. I'm just hoping the CM team finds a "fix" to make LTE/eHRPD a little more usable on AOSP roms. Sorry for the lack of advanced detail.. I know we all like that stuff. Of course, if I hear anything else I will update.

 

Thanks. It is disconcerting if true that Sprint's scheme for LTE authentication is inherently flawed and relies on finding some workaround. In any event, from field performance so far -- included tests of the Samsung GS3 -- it is apparent that there is not yet a solid solution.

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But what about the Viper and iPhone 5 are they having issues?

 

Sent from my EVO using Tapatalk 2

 

The iPhone certainly doesn't have this issue. I'm also not aware of any other data issues, aside from some users who have reported the phone has the wrong time.

 

 

Sent from my iPad using Tapatalk HD

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But what about the Viper and iPhone 5 are they having issues?

 

Sent from my EVO using Tapatalk 2

 

According to Robert when he was in Waco the Viper was connecting to LTE better than the Evo and the GS3.

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According to Robert when he was in Waco the Viper was connecting to LTE better than the Evo and the GS3.

 

The Viper and GNex auto connected to LTE fastest. The GS3 a little slower. And the EVO LTE rarely connected to LTE on its own.

 

Robert via Nexus 7 using Forum Runner

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