Why implement VoLTE when Net Neutrality is imposed?

Why implement VoLTE when Net Neutrality is imposed? As CSPs look to monetise the investments made in their LTE networks, Chris Ankers considers the question that “Net Neutrality” will encourage VoIP (voice over IP) use ahead of VoLTE (Voice over LTE) to the extent that investments in the technology may not be commercially viable.

Net Neutrality is the basic principle that internet service providers should treat all data on the network the same.  In the United States, Barack Obama’s Plan for a Free and Open Internet, was formalised in a statement issued through the White House, including the following:
 
No paid prioritization. Simply put: No service should be stuck in a “slow lane” because it does not pay a fee. That kind of gatekeeping would undermine the level playing field essential to the Internet’s growth. So, as I have before, I am asking for an explicit ban on paid prioritization and any other restriction that has a similar effect.

For Mobile Network Operators (MNOs), this directive is clear; their network should be open for competition, which includes VoIP and many other uses of the data and services available “over the top” (OTT).  So is this an open invitation for VoIP providers such as SKYPE and WhatsApp to piggy back on the LTE data networks to provide low (or zero) cost calls?

Today, VoIP applications are utilised as OTT services on the existing networks, but a 2G/3G network does not offer sufficient bandwidth to guarantee a good quality call. However, LTE networks change everything, with the potential of providing much better quality VoIP services given the increased speed and capacity of the networks (four to ten times faster than 3G).

What is VoLTE?
 
Long Term Evolution (LTE) is based on the 3GPP IP Multimedia Subsystem (IMS) specification, and as discussed previously on this blog in Using Technology to Solve Real Problems, the LTE paradigm facilitates many applications, one of these being Voice over LTE, known as VoLTE. By the end of 2015, there were expected to be over 100 million active VoLTE subscriptions globally, according to business intelligence provider visiongain, but can VoLTE continue to grow if net neutrality is imposed? 3GPP


Why VoLTE?

The obvious consumer benefit for VoLTE is the superior voice call that it delivers; 2G/3G voice networks generally use an 8kbps codec whilst the codec used over LTE will typically be 13.2kbps with more up to date 
compression techniques. Aside from the better quality audio it promises, VoLTE also benefits from the adoption of the GSM Association Rich Communications Services (RCS) where the voice and data services are truly integrated and due to the standards underpinning VoLTE become interoperable with other operators and devices. Overall, VoLTE should be a much better platform for us as consumers and a better user experience on our smartphones. And from the MNO’s perspective, the utilisation of their IMS infrastructure and increasing capacity within the spectrum are both further reasons to go to VoLTE.


What are the costs to support VoLTE?

True VoLTE requires full LTE coverage; but to implement VoLTE over infrastructure that includes legacy, there is a need to implement handover to the 3G/2G network mid-call.
Some MNOs have gone ahead and launched VoLTE services by using Circuit Switched Fall Back (CSFB) when out of LTE coverage. Others are adopting Single Radio Voice Call Continuity (SRVCC) to fall back to 2G/3G where required. However, CSFB and SRVCC are both expensive interim solutions, but this is the cost associated with being an early provider of VoLTE as an existing operator.

What is the future for VoLTE?

Putting in the network and the BSS/OSS for VoLTE will be inevitable for many operators because of the market they operate in and the customer demand for ongoing improvements to their service and user experience – VoLTE providing higher QoS and the ease of integration with the handset that RCS provides.
 
Other, more circumspect operators, who may work in more price sensitive markets, will have the opportunity to weigh up the cost/benefit of VoLTE and then choose to continue providing voice on their 2G/3G networks, using LTE for data services only, whilst retaining the revenue from voice services on their legacy networks. This will of course open the door to the OTT VoIP providers, but the data to support their services will remain a revenue stream for the LTE operator. 

Whatever happens, with the seemingly unquenchable thirst for more and faster data access, the need to plan and implement LTE networks and the corresponding BSS/OSS systems will be demanded from customers at least as much, if not more than it was for 2G and 3G services. 

VoLTE itself may not be adopted en masse in the same way that we have seen in the past for voice on the 2G/3G platforms, but we think that in time most operators will take the plunge and implement VoLTE.

Find out about the Cerillion Convergent Charging System which is built around the 3GPP charging specifications and provides diameter-based charging to support LTE networks and services.