By Julian Bright

For anyone who thought that voice over LTE (VoLTE) was the only thing sustaining the case for IMS, the evidence from Informa’s IMS World Forum, which was held this week in Barcelona, would suggest otherwise.

VoLTE may provide the mobile operator business case that IMS has been lacking, but the IMS faithful continue to see a far broader role for the technology, and mobile operators in particular are seeing IMS as a potential revenue-generator.

It was indicative of the continued interest in IMS that fixed and mobile operators made up over half of the delegates, at what turned out to be a lively conference. The debate revealed that while its supporters are still upbeat, they are realistic about the changed perception of the role of IMS in the network, particularly now that over-the-top players have shown that the proposition of an all-encompassing IP service platform can be readily circumvented.

In one sense, however, the IMS discussion has come full circle, with operators now asking whether voice alone can justify investment in an IMS platform, or whether the need is to support a range of rich IP-based services in order to be economically viable.

There was a high degree of consensus that in future IMS would have to pay its way. Deployments would need to be phased and ideally based on a segmented approach that could ensure customer take-up and a return on investment, before moving to the next phase.

The 160-plus delegates in Barcelona were polled by Informa in a live, interactive survey devised in co-operation with Huawei. Asked what were the commercial drivers for IMS today, a slim majority of vendors in the audience delivered a somewhat counter-intuitive verdict, by identifying capex and opex savings as the primary reason to deploy ahead of driving revenue growth. The majority of mobile operators, on the other hand, saw IMS more clearly as a means to drive revenues through service innovation.

Most agreed that the critical time will come in 12 – 24 months’ time, by which time IMS-based LTE voice may or may not have proved to be a building block for a richer set of VoIP-based services, and Rich Communication Suite (RCS), the third leg of the IMS mobile business case alongside FMC and VoLTE, will be seen either to have succeeded or failed.

According to the survey, vendors and mobile operators alike are putting their trust in the RCSe initiative, backed by a group of five leading European mobile operators and approved by the GSMA at this year’s Mobile World Congress, to help accelerate the adoption of RCS.

Meanwhile, vendors pointed to the complexity of developing end-to-end IP-voice services based on VoLTE as one reason that trials are currently taking up to 12 months. Most remained optimistic, however, that large-scale VoLTE implementations would emerge in the next two years, whereas the majority of mobile operators believed that VoLTE would take longer than two years to achieve significant scale.

Most of the mobile operators surveyed did not see RCS as mandatory alongside the deployment of VoLTE, although many saw a combination of the two as being a means of remaining competitive against over-the-top players such as Skype and Google. Others, including Canada’s Rogers Wireless who are already partnering with a number of OTT players, believe that IMS can provide a platform for greater co-operation between mobile operators and web-based multimedia providers.

Meanwhile, fixed-mobile convergence and PSTN network transformation continued to generate interest. Converged operators in particular saw positive benefits in the ability of IMS to provide service differentiation, and to blur the boundaries between fixed and mobile services and alleviate churn through service bundling.

The overriding impression is that while the future of IMS still hangs in the balance, the adoption of VoLTE and the latest push to commercialise RCS have at least extended the window of opportunity for IMS, and at best will provide fresh impetus to a technology that promised much but has so far fallen short in its delivery.