VoIP over 4G: The Future in VoIP Communications

Takeaway: The distinction between voice and data services is quickly falling by the wayside.

There’s no question that cellphones have become a staple in the U.S. - much like hamburgers or apple pie. A cellphone is no longer a status symbol. It's as common as having a traditional landline telephone, and in some circles it's even more common. But as cellphone use accelerates, it's clear that data and voice plans may be in for a dramatic shift. That is, unless something changes in terms of wireless voice communications methods and payment options.

If analysts were to put their ears to the ground, they just might hear such a shift occurring in the direction of Voice over Internet Protocol (VoIP) over 4G. Let's take a look. (Do some background reading on 4G in The Real Score on 4G Wireless.)

How Does 3G Affect VoIP?

VoIP has been nothing short of revolutionary in the field of voice communications, as private branch exchanges (PBX) are increasingly pushed aside in favor of smaller, highly functional, IP-based call managers. Following closely behind all of this mass migration to VoIP is the reality that VoIP remains largely an Ethernet or landline-based technology. Rescuing VoIP from its landlocked exclusivity has been no small source of blood, sweat and tears on the part of voice communications researchers. And the effort to incorporate VoIP functionality into mobile devices has, until recently, faced sizable problems.

Perhaps the most foreboding problem is rooted in the current 3G infrastructure which - in Verizon networks - requires the almost exclusive use of the code division multiple access (CDMA) channel access method. Simply put, CDMA allows multiple users to transmit bits on a given medium, and each receiver differentiates between these transmissions by virtue of a code assigned to each bit. Due to the physics involved with CDMA, voice and data are typically transmitted via separate but parallel networks - circuit switched for voice, and packet switched for data, and herein lies the problem. Facilitating a VoIP call via 3G technology is not impossible in and of itself, as 3G is capable of transmitting data via packet switched networks, but according to Voxilla, 3G networks are still too unreliable and too scarce to prevent large numbers of dropped VoIP calls. Furthermore, until recently, the technology that would allow an end user to move from one area to another while in the midst of a VoIP call simply did not exist.

Technology Involved

The rapid proliferation of 4G networks has led to an equally rapid advancement toward a VoIP solution that can maintain backward compatibility with legacy systems. According to Engadget, chip manufacturer Qualcomm successfully performed a voice call handoff from a 4G network to a 3G network in February 2012. This means that while conducting a voice call, Qualcomm officials were able to maintain connectivity when moving from an IP-based 4G network to a circuit-switched 3G network. This development was no small breakthrough, and could signal a solution to backward compatibility problems.

Perhaps the most prevalent standard in 4G communications is 3GPP Long Term Evolution (commonly referred to as LTE). What makes LTE networks somewhat unique within the cellular industry is that they are exclusively packet switched. So, unlike the CDMA networks mentioned above, there is no separate but parallel network used for voice and data. Within LTE, everything is routed through an IP-based core, thereby eliminating the need for a separate voice network. The advantages to an exclusively IP-based network include higher throughput and less inter-cell multiuser interference. In the end, the proverbial voice and data plans offered by virtually all cell phone providers might become a thing of the past.

What the Future Holds

In 2009, after much outcry from its iPhone users, AT&T began allowing the use of VoIP services in its 3G network. AT&T had previously disallowed this for unclear reasons. Some suggested that AT&T did not want to lose revenue as it pertains to the various voice plans offered to its customers. Others suggested that AT&T did not want VoIP services to overshadow its core competency as a telephony company. Whatever the reasoning, the distinction between voice and data services is quickly going by the wayside. (Read about how VoIP can affect network security in VoIP - Backdoor to Your Network?)