SON, your time has come – Julie Bradford, Managing Consultant

While self-organizing network (SON) technology might not inspire the same column inches as the hype surrounding 5G, for example, there are signs it’s finally starting to come back into the limelight.  In fact, I was recently part of a London conference wholly devoted to the subject, where a series of operator presentations left delegates in no doubt about the value and challenges of SON and automation both in today’s networks and on the path to 5G.

With 5G often described as a ‘network of networks’, such dense HetNets can be characterized as ‘multi-x environments’ – multi-technology, multi-domain, multi-spectrum, multi-operator and multi-vendor. As Small Cell Forum recently noted, these networks ‘must be able to automate the reconfiguration of [their] operation to deliver assured service quality across the entire network, and flexible enough to accommodate changing user needs, business goals and subscriber behaviours.’ And in networks comprising macrocells, large numbers of urban, enterprise and residential small cells, Wi-Fi access points, distributed radios and DAS antennas, it’s clear that optimization will be literally impossible without advanced SON at the heart of such automation.

But it’s not just the growing diversity of access mechanisms driving demand for sophisticated automation. The variety and complexity of services that are delivered by both network operators and over-the-top providers imply a huge range of customer experience expectations and network performance. Clearly, voice services over LTE are sensitive to packet loss, gamers struggle with latency, movies-on-the-go demand reliable buffering and so on; this is before the tsunami of 5G offerings ranging from augmented reality and the tactile internet, to sensor monitoring and first responder connectivity.

In addition, a number of conference speakers in London discussed virtualization and SDN in 5G networks.  Here there must surely be an opportunity for SON to help dynamically manage the ‘network slices’ of spectrum, sites, equipment, inter site transmissions etc. to deliver the right combination of services in the right place at the right time.   Many mentioned the idea of SON having to move from being re-active to pro-active as we move forwards on this path.

But in all this there is a danger that we are getting ahead of ourselves. At Real Wireless, part of our job is provide independent guidance around current investment decisions.  Many of the presenters at the conference were encouragingly operators who are actively using SON in their networks today.  However, much of the focus of real deployments was on automating radio planning and maintenance of sites which is still the tip of the iceberg in terms of what SON could achieve.  Also issues around interoperability, scalability and taking SON beyond the RAN appeared to remain a concern for operators, indicating that there is still plenty of work to be done to realize the full potential of SON.

Caroline Gabriel’s recent operator study concluded that automation and SON become entirely critical to the HetNet business case at a density level of about 10 cells per macro/50 cells per square km point, though SON was also considered highly desirable beyond three cells per macro/15 per square km. As network densification becomes more pressing, the case for reliable and interoperable SON will become increasingly urgent.