How SDN and NFV extend adoption and capabilities of self-organizing networks

Constantly increasing network usage, ever more complex service offers and the growing obsolescence of manual, time-consuming, error prone operations mean communication service providers (CSPs) must focus on optimizing their infrastructure. Self-organizing network (SON) solutions, for backhaul and core networks as well as radio access networks (RAN), can help them to do this.

SON is important in mobile backhaul networks because, in the drive to deliver end to end high quality services at low cost, the RAN is only part of the picture. The technological complexity of backhaul and core networks does make SON implementation challenging, but such solutions are nevertheless being deployed for self-configuration, self-optimization, and self-healing within networks. And, on paper at least, it looks straightforward. So what's holding some CSPs back?

The answer is the complexity of backhaul networks, which today support services substantially different from those they were designed for. Add in the evolution from 2G, via hybrid services to IP-only 3G and 4G, and the various geographical configurations and transmission technologies in operation, and it becomes obvious that any SON solution must manage a diverse, cross-technology, multi-vendor network. And let's not forget that the demands of 5G and IoT will soon make SONs a standard requirement.

Software-defined network (SDN) and network function virtualization (NFV) solutions underpin self-organizing functionalities in the backhaul. SDN refers to the protocols, standards, technologies and solutions that enable a network operating system to control network behavior, centralize some functions normally deployed in devices, and implement protocols and interfaces (APIs) required to program these devices. Thus, the SDN controller enables SON deployment in the backhaul by providing a platform for SON algorithms, standardizing the network programming interface and implementing the logic that defines network behaviour. NFV extends virtualization, allowing purpose-specific physical network devices to be replaced with generic resources running purpose-specific software independently of any physical device. The results? Significantly shorter time to market for new services, and greatly enhanced scalability.

Such a solution allows automatic configuration and optimization of the S1 and X2 interfaces for LTE sites, with SON defining their capacity and latency requirements, while the SDN controller chooses the route for the interfaces and deploys it to network elements. This also enables dynamic bandwidth allocation, solving the problem of inefficient and costly overprovisioning arising from static allocation.

For this to happen, SON solutions must be "aware" of network configuration, elements, topology and services, receive real-time information about network incidents and performance, and be able to make network configuration changes.

This is where Comarch's OSS architecture for SON shines. It relies on the OSS acting as a network operating system (NOS) integrated through various SDN-ready controllers. The NOS manages physical and logical resources, providing NFV MANO (network function virtualization management and orchestration). The SON is deployed as a network function on top of OSS, providing algorithms and network optimization functions, receiving data from the OSS, optimizing proposals, and delivering them to the OSS for provisioning.