IMS World Forum 2017 was an interesting mix of “more of the same” tempered with some interesting new developments that are moving into telecoms from the IT world. Of course, these domains have been growing ever-closer for some time, but there are still big differences in outcome and approach that have restricted telcos in a key area – agility. More on which later.

The key message from the conference is that IMS is here to stay but must change. Partly, that’s something people from both inside and outside the industry have been saying for some time, but it’s also partly due to a recognition that, now that IMS has confirmed its place as the core platform for VoLTE networks, it’s not so much a debate as to whether IMS is the right platform but rather about its evolving shape and form.

While the complexity of IMS has long been acknowledged, perhaps its spreading pervasiveness has expanded the community of users and technicians, with the result that the deep technical expertise that was dedicated to IMS several years ago has been diluted, creating growing demand for a less complicated approach.

To this end, several speakers (from both telcos and vendors alike) highlighted this need and pointed to a path in which a number of the functional entities might converge into a more consolidated framework. SK Telecom reported a huge decrease in TCO from condensing entities into fewer elements (60%)

At the same time, a consistent theme that several addressed is the growing recognition that not all communications are the same. We are beginning to move far from vanilla voice and messaging, into a much more blended world. As a result, there is increasing diversity in communications requirements, which means different levels of service and capability need to be supported, as well as more volatility in sessions – that is, sessions that move from one form to another in real-time. The current and forecast growth of IoT services will also have an impact, as these will create an even more diverse range of needs which, in turn, will place new demands on signalling and session control.

To cater for this, it’s likely that we will need more specific IMS-based solutions, which are purposed for different vertical markets and segments. The differentiation is likely to occur in the Application Function (AF) but some tailoring around the edges is also going to be required.

This was a persistent theme and vendors queued up to show how they would address it. Huawei, ZTE and Nokia all pointed to the adoption of micro services in their solutions. Specifically, micro services are seen as a way of enabling specific functionality in a layer above generic session control. Each container has a role, essentially as a micro services library above common control and data service layers. The idea is that a new micro service can simply be added to the environment without further change, although it remains to be seen if this approach will deliver what is promised. The key element here is the SBC function, which sits below the libraries. Of course, service specific SBCs are also consistent with this approach. But, stateful vs stateless remains a subject of contention.

One outcome of this would be to address the lack of agility in the industry. Since micro services are an IT concept that is extensively used by players that the industry recognises for their agility, the theory is that adopting it will also increase telco agility. That remains to be seen, but there is clearly promise for the future.

And, we are seeing the results of ongoing virtualisation and movement to the cloud. No serious vendor is not showcasing its cloud implementation and architecture to support cloud environments – which also includes various open-source projects. While SK Telecom struck a cautious note, warning that open source is not necessarily ready for carrier grade, others were more positive and pointed to massive deployments that prove their point. Time will tell.

Other interesting discussions centred around the inclusion of enterprise APIs – a topic long discussed, but which is now showing significant momentum. It seems telcos have finally stopped talking about the generality of developers (remember all the fruitless discussions about the so-called long tail?) and are focusing on specific, more valuable players, as we have long argued (cf Telenor’s MOVE project, which we have discussed in many places). It all comes down to who pays, and, from where can I secure revenue?

Other key topics:

VoLTE Roaming – there are two approaches to this (home routing and local breakout) and each has issues, but mobile operators are now moving to address the challenge. It’s an ongoing project though and issues such as lawful intercept and emergency service calls complicate matters. It’s easy to overlook the importance of the latter but it should not be underestimated. Again, that’s a reason to highlight the key difference between service providers and their colleagues from the internet domain.

Device control – we are moving to an unfettered market in devices, which is a good thing, especially as we may soon see $25 VoLTE-capable devices, but this means that device control is moving away from operators and they have to be able to cope with an increasingly diverse device fleet. While control is essential today, they will need to have less control in the future, which means they need capabilities to support new devices as they enter the market, without disruption or draining their support resources.

5G – everyone is talking about it, so it would be rude not to, but what is really happening? The 5G ecosystem is highly fragmented and there are many different demands. One speaker said that we need a circuit switched function in 5G, but that’s a topic for another time. The main point is that it’s approaching – rapidly – so developments in cloud and virtualisation are helping to pave the way for new service delivery models.

Network Slicing – an important innovation to reserve capacity across a deployed network, on-demand, for the enablement of parallel service layers, which might be dedicated to a specific provider (MVNO A, MVNO B, MVNO C, etc.) or for a specific service (NB-IoT, LoRa, autonomous public transport, etc.).

Sadly, I was only able to attend the first day of the conference but had the pleasure of presenting the IMS awards at the end of the sessions. These were most interesting and it was great to see more contenders. I’d like to see more operator categories, as IMS remains a key area in which operators are showing as much propensity for technical innovation as vendors.

So, on balance, we’ve reached an interesting transition. VoLTE is here, IMS is widespread and we are poised to solidify 5G. Virtualisation and the cloud are taken for granted (I remember a technical expert from a leading vendor poo-pooing the idea just a few years ago), so we have clearly moved far. But, the next year will see key challenges being addressed, as VoLTE moves increasingly to ViLTE and VoWiFi and as roaming is finally solved.

The real challenge will be reconfiguring IMS to support 5G cases, as this will clearly become a pressing concern. I suspect that will draw upon micro services to a much greater extent, as operators seek to deliver new, non-voice services that require specialised capabilities – and as the IoT industry wakes up to issues such as QoS and the dynamics of cellular connectivity (key point for them – they are not constant!).

It is this movement beyond voice and person to person communication that makes things interesting right now – new communications services that have radically different requirements from the voice and messaging that has long dominated the industry. And, session control remains fundamental, so irrespective of the eventual shape of IMS, something has to fulfil this role and we may as well call it IMS for now.