Voice over LTE yet to gain acceptance

September 3, 2012

The voice technology that allows for telephone conversations over Long Term Evolution networks, rather than requiring a carrier to fall back to 3G or 2G networks when making phone calls seems to a preserve of few mobile operators globally. The technology was developed in 2009 by the GSM Association and it has seen little take-up to date largely due to availability of compatible devices and ongoing moves toward 4G deployments. Voice over LTE is one that will have its time but it’s not one that is a high priority for many mobile operators unless they start to see multimedia and some value-add that goes with it, it’s pretty well recreating voice over a packet network in my own assessment.Most network operators seem comfortable with the performance of voice over their existing network. HD Voice is an existing alternative that allows for clearer voice signals over the 3G network by doubling the voice frequency range from 3.5 kilohertz to seven kilohertz while introducing noise cancellation technology and most have recorded dropout rate of less than two percent on their networks.

HD Voice is a technology, a version of which is baked into the Voice over LTE standard.Mobile operators should understand that to continue this paradigm, they all need to adopt a common technology and need to sign up to continue to interconnect exhaustively with each other.Obstacles to take-up have been a mix of device availability and the ability to easily fall back to legacy networks outside of 4G coverage.Lately, device makers are slowly gaining speed on VoLTE compatibility with Samsung Galaxy S3 being a prime example.Like HD Voice, device compatibility is likely to gain critical mass over a period of couple of years but the move to all-IP packet core networks underlying mobile networks is also a pre-requisite for a successful Voice over LTE network. Another barrier is Single Radio Voice Call Continuity technology, allowing carriers to switch from packet-based voice transmission like VoIP to the traditional circuit-switched voice networks still used by mobile carriers and across copper networks.The handover is complicated because not only does the radio interface change, but also the bearer for the call has to move from an IP-based VoLTE bearer to a circuit-switched model. All of this needs to happen without the customer noticing and this has presented a real challenge and also has a handset impact.

Contador Harrison