Verizon Wireless is set to join the other U.S. carriers in offering Wi-Fi calling. The company has secured a temporary Federal Communications Commission exemption from rules requiring voice over Wi-Fi to accommodate hearing- and speech-impaired users. AT&T Mobility requested and received a similar waiver before launching its service.
The nation’s largest wireless carrier follows AT&T Mobility, Sprint and T-Mobile US into Wi-Fi calling, although each carrier’s offering is unique. AT&T Mobility currently supports only the recent versions of Apple’s iPhone with Wi-Fi calling (iPhone 6, 6 Plus, 6s and 6s Plus), while Sprint and T-Mobile US offer the service on some Android phones as well.
Voice calls over IP networks have been available for years through services like Skype, but carrier-supported Wi-Fi calling integrates the service so that calls and messages can be seen alongside those made over the cellular network. Call transfers from cellular to Wi-Fi are at times difficult, but will become easier as carriers roll out voice over LTE, which is also IP-based. AT&TÂ Mobility said that handoffs between its VoLTE network and Wi-Fi are working well so far.
Verizon Wireless has made no announcement yet about when or how it will launch voice over Wi-Fi, or about whether or not Wi-Fi calls will be free for users who pay for voice minutes. While Sprint and AT&T Mobility say they don’t charge for Wi-Fi calling, T-Mobile USÂ does count Wi-Fi voice calls against monthly minutes for users of its Simple Choice plans, though most of those plans offer unlimited calling minutes.
Wi-Fi-first operators are offering low-cost wireless plans that rely primarily on Wi-Fi for voice and data, and move users to cellular when Wi-Fi is not available. Republic Wireless, Scratch Wireless and Google Fi all follow this model. Cablevision has launched a service called Freewheel that does not include a fallback to cellular; the cable operator is promoting the service as a good fit for those who live, work and play within range of Wi-Fi.
Verizon Wireless is probably the laggard in offering voice over Wi-Fi because of its robust LTE network. The carrier boasts good coverage nationwide, and has roaming agreements with rural operators to keep its customers connected in sparsely populated parts of the country. Verizon Wireless is also a leading proponent of LTE in unlicensed spectrum, which would enable the carrier to charge customers for using voice and data services in the spectrum that is now dominated by Wi-Fi.
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