Mobile operators' voice revenues are heading south, as customers increasingly choose to use free voice-over-IP (VoIP) services like Skype rather than their regular 2G services. But voice-over-LTE (VoLTE) could be an opportunity for them to steal back market share, according OpenCloud.

As 4G LTE services launch in the UK over the next year, operators will gain access to additional bandwidth and economies of scale that will reduce the delivery costs of data. This means that they will be able to offer high-bandwidth services, like HD video and voice, for a fraction of the cost that they pay now.

Over-the-top (OTT) providers, like Skype and Viber, will also benefit from the low cost of bandwidth – potentially enabling them to take an even greater share of the market. However, Mark Windle, head of marketing at OpenCloud, the open software platform provider for telecoms companies, believes that delivering a complete voice service over LTE is about a lot more than just setting up a connection between handsets.

Speaking to Techworld, Windle said that VoLTE will provide operators with the opportunity to establish voice and video propositions that the OTT providers simply cannot match, with the provision of voicemail, roaming and interconnect – all the services that subscribers take for granted when using mobile voice.

“There's a difference between using your O2 or your Vodafone service and using Skype. For one thing, you have much broader connectivity. When you make a call using those operator services you can instantly reach about 4 billion people worldwide, whereas when you're using Skype you're limited to the user groups within Skype,” said Windle.

“GSM voice services are also suitable for emergency calls, which is a huge comfort factor for most people. A lot of the reason young kids get phones from their parents is because they can get in touch with them in an emergency. An extension of that is being able to call for an ambulance or the police if you need to.

“Furthermore, you get all the other bundled services – so being able to set up call divert, being able to set up your voicemail, and then on top of that there's a whole load of business services as well which provide things like VPN solutions in the network or short-code dialing between closed user groups.”

Windle said there are a whole host of reasons why using your mobile phone is actually a little bit better than VoIP. However, in order to deliver those services more cost effectively, and also compete with the OTT providers on HD voice, the operators need to be looking at LTE.

“They have got to take this existing service and, without losing any of those rich features that it currently has, transport it across to voice-over-LTE,” he said.

This is where OpenCloud comes in. Opencloud offers an open software platform that sits within the heart of the telecoms network and allows operators and third part developers to build new services and applications on top of it.

The platform acts as a service control point for SS7 and IP Multimedia Subsystem (IMS) networks. It provides real-time control of calls, messaging and data, and is also used as an application server.

“Because our platform can connect across both legacy networks and IMS networks simultaneously, it connects to a whole array of network elements – so HLRs or HSSes, switches, messaging centres, subscriber profile databases,” said Windle.

“You have that very flexible array of interconnectivity within our platform, and because it's open and anyone can develop applications, it means that operators don't have to wait for standardised solutions to come down the pipe and then wait for their vendor to implement it.

“They can do their own thing on day one, while the standardisation is going on, and then they have this low cost platform where they can make the changes themselves or ask independent developers to come help them make the changes,” he said.

By adopting a service layer solution that supports IMS for LTE, and which can also connect back to the legacy network service layer, operators will be able to deliver telco-grade call services quickly, simply and at low cost, according to Windle.

These services, connected via guaranteed bandwidth connections and with seamless handover at cell boundaries, come with a quality of service that sets them a league above the OTT alternatives.

“Voice over LTE is very much an afterthought in the industry – very surprising actually, given that voice revenues are still the lion's share of their income. They kind of planned LTE without really thinking about voice.” said Windle.

“Skype will be available over LTE, therefore the operators need to do something that is at least comparable, and that will naturally lead to voice-over-LTE,” he concluded.