[Jaylou180]

I've been having trouble with simultaneous voice and data on the nexus 4 on AT&T. I've tried several apn settings and still nothing. Whenever I'm on a call the data signal turns grey and I have no data. Anyone else experience this problem

[2defmouze]

I've been having trouble with simultaneous voice and data on the nexus 4 on AT&T. I've tried several apn settings and still nothing. Whenever I'm on a call the data signal turns grey and I have no data. Anyone else experience this problem

Can't speak for Att... On Tmobile $30 prepaid I'm getting HSPA+ full data while talking on the phone.

[raysgrumpy]

I've been having trouble with simultaneous voice and data on the nexus 4 on AT&T. I've tried several apn settings and still nothing. Whenever I'm on a call the data signal turns grey and I have no data. Anyone else experience this problem

I'm on T-mobile and I had that happen once a few days ago. Other than that, I've had great data speeds while talking.

[ex3me4me]

I've been having trouble with simultaneous voice and data on the nexus 4 on AT&T. I've tried several apn settings and still nothing. Whenever I'm on a call the data signal turns grey and I have no data. Anyone else experience this problem

Same to me with AT&T Tried couple of APN no luck. Most of service lost while i'm using it in my car via bluetooth.

[Freshly_Snipes]

Same to me with AT&T Tried couple of APN no luck. Most of service lost while i'm using it in my car via bluetooth.

It's not available on AT&T's newer HSPA+ 21mbps bands in most cities. It's an AT&T limitation. Only Tmobile AWS bands.

Sent from my Nexus 4 using Android Central Forums

[Parth Ghetia]

Are we sure it's a problem with AT&T? It could be a bug in the modem firmware since it's remedied by forcing WCDMA only.



To anyone who reads the issue, please star it so it can get Google's attention ASAP. I find this to be a big issue.. don't know why it's marked as "medium."

[dan1431]

Granted, I do not have any first hand knowledge, but I was talking with my neighbor (who is an RF Engineer with SPRINT and I do realize that SPRINT is CDMA but he understands RF Theory and Wireless Comm in general and is able to extrapolate to GSM) and he said it sounded to him like it could be an issue with the Nexus 4's modem's firmware playing nice with certain network hardware (i.e. Alcatel-Lucent HW and Ericsson HW).

A few data points:

1. In my home area of FL (Southeastern FL Palm Beach County) I am able to maintain a simultaneous Voice and DATA connection
2. While visiting NYC I was not able to maintain a simultaneous Voice and DATA Connection
3. While working in Los Angeles (near Manhattan Beach) I was able to maintain a simultaneous Voice and DATA connection.

He came to this conclusion after I explained the above DATA points to him and said that network HW is the most likely culprit.

If it is network HW and the Nexus 4's modem firmware it also would explain why a poster above on T-Mobile experienced being unable to maintain a simultaneous Voice and DATA connection as T-Mobile uses a mixture of Ericsson HW and Nokia Siemens HW.

Dan

[Avenger]

Works fine in Canada with Rogers/Telus/Wind Mobile. Haven't tried Bell but I imagine it would be the same successful results. Must be the provider and their hardware.

[jimmiekain]

I am using straight talk with an at&t sim.

I have almost the same problem. For me the data either works really slow or not at all. It still says H though. I have checked and I'm in a HSPA 10 area. Every once in a while it will say HSPA +15 but it always switches back to normal HSPA with no + in a second or two.

[PhilSterBoy]

Must be a carrier limitation I get Hspa and talk on WIND here in Canada

Sent from my Nexus 4 using Android Central Forums

[Parth Ghetia]

Simultaneous voice+data works fine on AT&T with my GT-I9100. Same plan, and everything. It's just the Nexus 4 with this problem and I'm pretty sure it's a modem firmware incompatibility with certain cell site hardware that Google or LG needs to fix.

[dan1431]

I wanted to bring everybody up to date RE: this issue.

Over at I and others have been doing some research on this issue and we MAYBE close to a solution.

Two at&t employees have filed SEPs (Service Escalation Process) RE: the issue and at least a few of those SEPs have been accepted. I talked with an at&t Engineer and while he was not able to see the issue himself (as my area does not seem to affected by this issue) felt it might be N-SET.

Dan

[weiny]

I am having the same issue and its driving me insane. Who is able to fix this and how can they do it?

[donm527]

wondering why this thread is under the ROM section and not the main section to get more discussion?!

I was just browsing and see this thread and had no idea that I could be limited with voice/data issues...
i just tried it on mine and surprised to see i am getting slow to hanging when trying to use data with a call on line.
i guess i'm going to live with it and hope that a sw patch can fix because I have no problems with voice/data with the same sim on my 4S and the 4s has hspa+ even though not 24 capable.
if i knew this before buying the n4, it could have been a deal breaker for me.

I am using straight talk with an at&t sim.

I have almost the same problem. For me the data either works really slow or not at all. It still says H though. I have checked and I'm in a HSPA 10 area. Every once in a while it will say HSPA +15 but it always switches back to normal HSPA with no + in a second or two.