Apple to develop VOIP service?

telephony software engineers to work on new iOS products, according to job postings on the company's Web site, Light Reading reports.

However, it's not clear from the job descriptions exactly how the device maker plans to support voice services on LTE smartphones.

One of the job descriptions calls for someone with "experience in SIP, real-time transport protocol and voice over Internet protocol (VOIP)”.

There has been speculation as to what architecture Apple will use when it begins to offer voice services on expected upcoming 4G LTE handsets, but the new job ads give a glimpse as to what the company could be planning, Apple Insider says.

"Whatever Apple does, it will want [voice] to work on its cellular and non-cellular devices," notes Dean Bubley, founder of consulting firm Disruptive Analysis. "Any voice platform will need a non-SIM mode [like] an over-the-top extension of IMS. Apple won't want a completely different voice experience on the iPhone and a WiFi-only iPad."

Apple is also looking for engineers skilled in IP multimedia subsystem (IMS), which is a key component of the One Voice initiative that many of the world's largest operators have adopted to migrate voice from circuit-switched systems to all-IP voice networks, Bloomberg Businessweek states.

Verizon Wireless and MetroPCS already use the architecture in their LTE networks, and AT&T and Sprint are implementing IMS to power their future voice and SMS services.