I am having an intermittent problem and I was hoping to get some advice. A little background - I have had Verizon as a carrier since the company was formed in 2000. Prior to that I was a subscriber of one of their legacy carriers. I mention this because, although I have tested the other carriers occasionally, where I live, work and travel, I find Verizon to be the best carrier for me hands-down. Up until the iP5 launch day, I had a 4S and a 4 before that. My wife now has the 4S. When the iPhones were 3G only, I never had a signal issue. I never missed calls and I never dropped calls and I never had an issue placing calls. Since having the iP5, I have been having missed call issues and, at times, have been unable to place calls. What I mean is that the phone will not ring and I will just receive a voicemail notification. People tell me that when they call me, the call goes straight to voicemail. This even though the phone is on, not in airplane mode and in a good signal area. Also, there are times when I go to place a call and the call will not complete. When I press Call, it switches to the call screen, where it stays for about 30 seconds, the call fails and my signal indicator switches to "Searching" and it takes about another 30 seconds to pick up a signal before I am able to place a call again. This can happen when my wife is standing right next to me with 5 bars of 3G signal. Here I what I have done/researched/attempted so far. - These issues only happen when the phone is on LTE. The LTE signal is good and not marginal. By that I mean at least 4 bars. -If I turn LTE off, this issue never happens. I tested this for two weeks. The problem here is why have an iP5 if I have to shut off LTE? -This never happens with my wife's 3G-only 4S -I went to the Apple store and they replaced the phone. Still continues to happen. -I have reset the network settings multiple times -I have factory reset and reinstalled iOS several times. -I never drop calls. Only miss them outright or can't place them. The only thing left that I can think of is potentially a SIM card problem? Does anyone have any experience with a similar issue? I hesitate to have the phone replaced again because I find it hard to believe I would have the same hardware issues on two separate devices. With Verizon, LTE is currently used on the iPhone for data only and the voice is handled by the CDMA side of things. So when placing or receiving a call, maybe there is some kind of radio handoff that happens behind the scenes. For example, if I am using LTE to browse the web and I receive a call - the LTE radio has to shut down, allowing for the voice side to deliver the call to me. I can't help but wonder if this handoff is causing the issue in my phone. Perhaps, for some reason, my phone is not managing this properly. This is why I am thinking SIM card issue. Although - in a Verizon LTE iPhone - what would the SIM card have to do with the voice side of things? Alternately, there could be a problem in the switch with my line. Back in the BlackBerry days, there was in issue in the switch and it caused me many data problems. Anyway - if anyone has any similar experiences or suggestions, I would love to hear them.