VoLTE Call Flow- Voice Over LTE Call Flow

VoLTE call flow and procedures are terribly huge space to cover thanks to the various situations to contemplate from each UE and network perspective.

In this article, I’ll try and place some samples of VoLTE call flow from UE purpose of read. These procedures are the most vital for VOLTE calls.

From the UE’s purpose of read, the initial step is to camp on the network and browse system data within the variety of Master data Blocks (MIBs) and System data Blocks (SIBs). Once that data has been processed the UE will initiate its own processes.


volte-sip-call-flow volte-eps-attach-for-lte

Using Wi-Fi Calling And VoLTE

In iOS 8, the iPhone now supports two new calling features, Wi-Fi calling and Voice Over LTE. Wi-Fi calling allows you to make phone calls over a Wi-Fi network rather than through your provider’s cellular network, which is great in situations where you’re not getting strong signals from your provider, and it also means your calls are free since they take up none of the minutes from your calling plan when you’re calling over Wi-Fi. As I record this movie, Wi-Fi calling is available on the iPhone 5c, the 5s, and the iPhone 6 and 6 Plus. Voice Over LTE or VoLTE allows phones to be made over LTE cellular connections.

Now, high-speed LTE signals have been available for a few years now, but until recently they mainly handled data. LTE networks allow you to download images, videos, and so on at much faster speeds than 3G and 4G networks. But LTE networks weren’t equipped to handle voice calls. So the calls still went out over the older networks. As I record this, this is still the case. Here in the fall of 2014, the only U.S. provider who has enabled Voice Over LTE so far is T-Mobile. And it’s still not available everywhere in the country.

Verizon has also announced that they’ll support the service in 2015, but that remains to be seen. But the good news is that there’s nothing to do in order to use Voice Over LTE. Once your provider makes it available, your calls will just go out over the LTE network whenever it’s possible.And you should notice that they sound much cleaner and crisper. But using Wi-Fi calling does take a bit of setup, so let’s take a look at how this works. Again, as I record this movie, so far the only U.S. provider to have enabled Wi-Fi calling is T-Mobile, but it should work the same way for each provider. Start by going to settings and then phone, and here you should see Wi-Fi calls.

I’ll turn on allow Wi-Fi calls. Now, you may see this message telling you that other devices won’t be able to make or receive calls through your iPhone. If you recall from a previous movie, I showed you how on iOS 8 you can now receive and make calls through your iPad, iPod Touch, or Mac as long as you’re on the same Wi-Fi network as your iPhone. But with Wi-Fi calling enabled that won’t be possible. But you can always come back here and turn Wi-Fi calling off if need be, so I’ll tap okay. Now, in order to activate Wi-Fi calling, at least here in the U.S., you have to provide 911 contact information.

That’s because when you call 911 over a Wi-Fi network, their dispatchers can’t tell where you’re calling from. And in an emergency situation that can be a pretty serious problem. So you have to enter contact information here even though you may not be at this location if you ever have to call 911, but it gives them something to go on. In most cases, you’ll probably want to enter your home address. Once you’re done here, tap save. And now I get this confirmation screen. And notice that it says here you can edit the address whenever you want. So if you move or want to enter a different 911 address, as it says here, you can just go to settings, phone, Wi-Fi calls, and then select update emergency address.

I’ll tap close, Wi-Fi calls are enabled, and notice we do have that update emergency address button now. But once Wi-Fi calling is turned on, that’s it. Any calls you place while on a Wi-Fi network will be transmitted over that Wi-Fi network. Calls coming in will come in over that Wi-Fi network. And calls you place will go over the Wi-Fi network. But the people you’re calling will still see your regular caller ID. Now, if you happen to leave the range of your Wi-Fi area during a call, if you’re an iPhone 5s or 5c, the call will end. But if you’re on an iPhone 6 or 6 Plus, the call will automatically switch over to using Voice Over LTE without interruption but only if Voice Over LTE service is available where you are.

All right, so that’s how to enable Wi-Fi calling on your device. Again, as I’m recording this, this is a brand new feature. So check with your service provider to see if they have or can enable Wi-Fi calling on your iOS device.

Know more:   How to flash custom ROMs on the Moto G Second Generation