A new set of job listings noticed by LightReading continue to show Apple’s focus on implementing VoLTE, or voice-over-LTE, support for including high quality call quality on new iPhones.

Specifically, the job listings seek both a Cellular Systems Protocol Engineer with hands-on experience in wireless technologies including VoLTE and an iOS Wireless Communication Software Engineer with “SIP, RTP, and VoIP related protocols”, showing the company is continuing to beef up its expertise around the technology.

9to5Mac first reported that Apple is targeting voice-over-LTE support for iOS 8 and future iPhone models earlier this year in April:

Another significant addition being considered for iOS 8 and the next-generation iPhone is voice-over-LTE support (VoLTE), according to carrier sources. Currently, when an LTE-capable iPhone needs to make a phone call, the actual call is placed over last generation networks such as 3G. With VoLTE, calls will be transmitted over the same type of network that LTE data is processed through, and this can allow for benefits such as improved call quality.

9to5Mac further reported on Apple’s plans for future VoLTE support in May of this year:

While the iPhone’s chipset can support calling over LTE, the iOS software does not actually have the ability to make calls over LTE networks. According to people briefed on Apple’s plans, this may change this fall with iOS 8 and the iPhone 6.

While data has been handled over the latest generation LTE networks since the release of the iPhone 5, voice calls have still relied on using older 3G networks for handling calls. Support for VoLTE would have the effect of increasing call quality by taking advantage of the newer networks.

Carriers in the United States have already began sharing details about their plans to roll out support for voice-over-LTE. Verizon announced earlier this month that it plans to launch its VoLTE service the the last quarter of this year. T-Mobile shared last month that its VoLTE service now covers 100 million people while AT&T has also announced VoLTE support.

FTC: We use income earning auto affiliate links. More.

Check out 9to5Mac on YouTube for more Apple news: