Apple looks to be gearing up for HD voice-over-LTE support

Apple appears to be gearing up for high-definition voice-over-LTE (HD VoLTE) support in future mobile products The company is currently advertising for a cellular systems protocol engineer, calling for experience with “VoLTE” and “IMS.” Other positions are calling for experience with the Session Initiation Protocol (SIP) protocol. VoLTE uses SIP to initiate the 4G calls, which are transmitted in data packets, with the IP Multimedia Subsystem (IMS) in the core network controlling the call session. There’s a useful primer on how this all works here.

Apple has already said the iPhone 6 will support calls over Wi-Fi, but what about voice over LTE? No, the company hasn’t mentioned that, but there’s an outside chance the feature will be added to the next iPhone: Apple has posted job openings for engineers with VoLTE experience. Light Reading’s Dan Jones spotted several related job postings and speculated on an iPhone 6 surprise. The company is looking for experience with VoLTE, IP Multimedia Subsystems and the Session Initiation Protocol — all of which add up to future voice support over fast data networks. Apple is also seeking people to help with Adaptive Multi-Rate Wideband (AMD-WB), a codec used in the VoLTE standard. If you’re looking for VoLTE support at the launch of the iPhone 6, the timing of this development isn’t ideal: Apple is expected to hold, but hasn’t yet announced, a press event on September 9 to unveil the iPhone 6. If the company is just now seeking VoLTE engineers, it would be nearly impossible to debut native voice over mobile broadband support on a new phone. However, as Fierce Wireless notes, Verizon has said it will debut VoLTE service in the fourth quarter of this year. Other carriers also have timelines to switch voice services over to data networks: AT&T has done so in a few select markets with a single phone model, for example, and T-Mobile also offers the service.