The new iPad is the first 4G device from Apple and the next iPhone, dubbed iPhone 5, is all set to be second. But a job posting at Apple Web site reveals that the tech giant may add more connectivity features to the upcoming iPhone.

Apple is looking forward to implement various wireless telephony services on its upcoming iPad and iPhone. The skills sets provided in the job description reflect that the tech giant is searching for developers to fit with its VoIP schemes. According to the job listing, Apple is searching for iOS telephony software engineer with deep knowledge in IP multimedia subsystem (IMS), session initiation protocol (SIP), and real-time transport protocol (RTP) and Voice over Internet Proxy (VoIP) related protocols.

Also, knowledge about various network standards like GSM/UMTS and CDMA is required.

Of particular interest is the IMS architecture as most of U.S.-based network carriers are planning to implement it on their 4G LTE networks. Verizon Wireless and MetroPCS are already executing IMS.

However, at the moment we cannot assume that the tech giant will completely rely on IMS for communication in future gadgets. Verizon is expected to release Voice over Long Term Evolution (VoLTE) network service later this year. The wireless carrier reportedly is testing VoLTE at the moment.

We are making grand speculation based on a relatively small piece of evidence. But that's what Apple is about. In fact, many Apple fanboys are suggesting that Apple is launching its own voice service infrastructure that will eliminate U.S. carriers like AT&T, Verizon and Sprint to sell iPhones.

Upcoming iPads and iPhones will need clients with Session Initiation Protocol (SIP) in order to communicate with IMS architecture of wireless carriers. And this job posting makes it more likely that Apple is looking for expert programmers to do that. Apple is already on the road of abandoning network carriers by its services like iMessages for SMS, FaceTime for video calling and now it seems it will have its own VoIP service in place of network telephony.

(reported by Johnny Wills, edited by Surojit Chatterjee)