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Simplifying IMS

Among the many topics of discussion at the IMS World Forum, that of simplifying IMS attracted considerable attention. Of course, it’s hardly a new subject but unfortunately has often been co-opted into a wider argument about whether or not IMS was even necessary, which leads to lots of pointless debate. Since the reality is that IMS has gained momentum independent of such arguments, it was easy to neglect the fact that the point about simplification had a good deal of merit.

However, it’s still a valid question. IMS is complex and has become even more complicated through a process of accretion, as you can see from our presentation. New functionality has been debated through the 3GPP meeting processes, considered and then added to the already weighty specifications. Regulated operators have many conditions they are required to meet – a point we made during our presentation – and so the tendency has been to opt for safety first and to bolt everything into a standard specification.

Take emergency calling, for example. How many OTT providers support this? The answer is very, very few indeed. But how many operators must support this and the answer is very different: all have to. During our presentation, I asked how many people in the room had ever used an emergency service and, I think, only two of us answered yes (I was one of them). Despite the small chance of ever having to use such a service, operators are still obliged to offer them, which places a burden on them and conditions thinking and culture in many respects.

Conditioned by these requirements, operators tend to think that they must deliver services even when there is only a small community of users – that’s why RFXs for new or replacement services are often full of clauses which demand exact replication of an earlier offer, no matter how little used some features were, much to the frustration of vendors. Why not just turn some things off if the user base falls below a certain number? Of course, this can’t be done with an emergency service but the logic behind supporting these should not be extended to every other service in the operator portfolio.

Emergency service support is something that has been added to the IMS standards, through the inclusion of the IMS PSAP and the integration of mandated location capabilities. The result that an already complicated set of specifications became yet more complicated – and more things have been incorporated as operators and vendors have agreed that they need to be supported in a standardised way.

And yet, I can’t help but wonder if the obligation to provide such a service hasn’t been confused with the means by which it is realised. Surely existing capabilities could have been leveraged for the delivery of emergency services rather than going through a complex process of defining more functional entities and adding to the standards? After all, we have session control, we have media resources and we have location data that can be obtained from multiple sources. The additional complexity could have been avoided if instead of pursuing yet more standardisation, implementers had just got on with the job of realising a solution to a legal requirement.

It’s this kind of thinking that has created more complexity than we need. As the next generation of virtualised, cloud-based solutions is being prepared, it’s time to reconsider if we really need the extreme decomposition that resulted from the IMS standardisation process. We need clarity, we need innovation and we often need to meet legal and regulatory requirements. But we don’t need to define exactly how all such requirements are implemented, just that they are made available.

That’s why simplifying IMS is now a very relevant question and one that needs to be pursued. But it needs to be done so in an open way that is sensitive to the needs of innovation and external requirements. We’re already looking forward to the next edition of the forum. During the coming year, we expect to see much discussion of the topic and some real initiatives from stakeholders to deliver a simplified form of IMS that is ready and fit for 5G and the virtualised world.