Verizon Wireless (NYSE: VZ) started rolling out Voice over LTE service nationwide but is initially making VoLTE available on only two smartphones: the Samsung Galaxy S5 and LG G2. The carrier had promised that a "robust" lineup of devices would come with its VoLTE launch, and vowed that more will come soon.
Officially, Verizon is calling its VoLTE and HD Voice service "Advanced Calling 1.0." The company noted that with Apple's (NASDAQ: AAPL) iPhone 6 and 6 Plus, which support VoLTE and HD Voice, Verizon customers will able to experience simultaneous voice and data on iOS for the first time. Verizon spokeswoman Debi Lewis said that "the list of supported devices will grow over time through software updates and new devices, too."
Verizon has been seeding its customer base with smartphones that are capable of supporting VoLTE but will need to issue a software update for the devices to launch the service. However, Verizon has not said which devices will get the update to enable VoLTE.
Once existing customers with VoLTE-capable phones get the software update they can enable the feature by logging on to their accounts online and choosing to do so. Customers can also activate the service when they buy a new VoLTE-capable phone.
Importantly, to experience VoLTE, both parties on a call will need to be using a VoLTE-enabled Verizon smartphone. Not all new Verizon phones going forward will necessarily support VoLTE.
There is no extra cost to use Verizon's VoLTE service. HD Voice minutes will be deducted from a subscriber's normal voice-minute bucket. Video calling gets deducted from a subscriber's data bucket. Importantly, Verizon says that a video call using VoLTE will consume around 6-8 MB of data per minute of calling.
Most critically for Verizon's VoLTE service, if a customer is not on a call and the phone is in the idle state and drops out of LTE coverage, the phone will automatically switch over to CDMA 1X voice service. However, if a customer is on a VoLTE call and drops out of LTE coverage, the call will disconnect. Customers can also to turn VoLTE on and off in their phone's settings and return to CDMA 1X voice service.
In a post for customers, Verizon noted that "calls won't switch between 3G and 4G LTE networks. If your call starts on the 3G network and you move to a 4G LTE coverage area, your call will continue as a 3G/CDMA call. However, if your call starts on the 4G LTE network and you move to a non-4G coverage area, your call will drop."
AT&T Mobility (NYSE: T) and T-Mobile US (NYSE:TMUS) also support VoLTE, but because they have GSM and HSPA legacy networks, when customers on VoLTE calls drop out of LTE coverage their calls will not drop, thanks to a technology known as Enhanced Single Radio Voice Call Continuity (eSRVCC).
AT&T offers VoLTE-based HD Voice in select areas in Illinois, Indiana, Minnesota and Wisconsin and said it will "continue to expand on a market-by-market basis to ensure the best possible customer experience." AT&T only supports VoLTE-based HD Voice on the Samsung Galaxy S4 Mini right now but plans to add more phones that support VoLTE.
Kris Rinne, senior vice president of network technology at AT&T Labs, recently noted that the Galaxy S5 is one of the devices that already has VoLTE capability. "We've already got several compatible devices available, and more coming for the holidays," she told Light Reading. Rinne said AT&T is taking a market-by-market upgrade approach with VoLTE. "We can do that because we have handover capabilities with the UMTS network," she said.
T-Mobile's VoLTE phones include the Samsung Galaxy S5, Galaxy Light and Note 3 and the LG G Flex, and the carrier is working to add more devices soon.
Sprint (NYSE: S) has not given a timetable for when it will launch VoLTE. Sprint has said that 16 million customers have access to HD voice service, two months after it launched the service nationwide. John Saw, Sprint's chief network officer, recently said that the improved voice quality offered by HD voice is taking the pressure off the carrier to offering VoLTE service.
"We want a solid VoLTE experience before we push it out," he said. Sprint's LTE network covers 254 million POPs, compared with 306 million POPs for Verizon and 300 million for AT&T.
- see these two separate Verizon posts
- see this Verizon FAQ
- see this Droid-Life article
- see this Engadget article
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