It wasn’t that long ago when customers had to navigate a long list of Internet service providers, wireless providers, and various fixed network providers, to achieve what has recently become a commodity in society: ubiquitous, always on, coverage. Today, with the advent of 5G and Internet of Things (IoT), the line of delineation that once clearly separated these worlds is slowly dissipating and becoming blurred; or in the prophetic words of George Costanza from Seinfeld: “Worlds are colliding!”
Traditional fixed operators are entering the wireless domain and, similarly, wireless providers are increasingly dipping their toes into the fixed waters. While this simplifies life for many consumers who can now turn to a single service provider for all their service needs, it can make it infinitely more difficult for operators who are now faced with the prospect of having to build or manage multiple networks to deliver the services customers require. Luckily, cooperation strategies and SDN/NFV are making life in this new world more palatable and manageable for all.
Like adding oil to a high-performance engine, software-defined networking (SDN) and network functions virtualization (NFV) can help eliminate the network friction that often comes with convergence. Helping the 2 worlds coexist, operators are using SDN/NFV techniques to achieve a single, dynamic, and adaptive network that can be managed centrally. It’s also helping operators increase automation and network programmability, push functionality into the Cloud, and seamlessly scale their current network environment.
In addition to streamlining functions and operations, SDN/NFV can be applied to help decrease the investment risk that can come from having to build a new, or overlay, network to support emerging requirements such as 5G backhaul. For instance, in the era of 5G, which requires higher frequency bands and up to 10 times more radio cells than current mobile environments, operators must ensure they have access to the capacity, latency, and scale, required to support the growing network densification and backhaul requirements 5G necessitates. While mobile operators can build dedicated networks to connect their cell sites to their core networks, this can be a very timely and cost-prohibitive solution. Instead, fixed networks are an alternative that can reduce the cost of backhaul by as much as 50% and eliminate the need for a dedicated network, according to an analysis conducted by Nokia Bell Labs.
Through virtualization and a technique called network slicing, which uses virtualization to partition the physical network into several virtual slices, fixed operators can effectively split the active layers of an access network into several virtual chunks that can be independently managed and defined for business, residential or mobile backhaul services. With network slicing, infrastructure providers can virtually open a portion of their network to wireless operators who can then manage and access the network slice in a fully independent way. This network slice can then be used to support 5G backhaul, delivering the capacity (10 Gb/s and higher) and quality of service in a far more reliable and economical way than current mobile backhaul alternatives.
Providing greater granularity than engineered partitioning, virtualization techniques such as network slicing are opening new doors to cooperation and collaboration that previously may have been more difficult under previous paradigms. It’s also helping to lower costs for operators, and increases the possibilities of co-investment in or sharing of next-generation fixed access infrastructure.
Collaboration and NETCONF/YANG
One of the key advantages of SDN is its ability to optimize end-to-end behavior across different technology domains, centralize functions, and bring different areas of the network together. It can also deliver far greater control and flexibility for operators looking to share their infrastructure via techniques such as network slicing. However, unless the protocols and APIs that are used to implement SDN and NFV into the network are open, operators may quickly become locked into a specific vendor’s capabilities that can limit the benefits they receive. Protocols such as NETCONF/YANG change that dynamic, creating an open environment that can deliver additional benefits over more traditional SNMP-based mechanisms.
With NETCONF, operators can more effectively manipulate and retain the configuration of network devices while YANG helps to model the configuration and state data of network elements. NETCONF allows operators to easily configure a range of devices or nodes (such as G.fast nodes) automatically while keeping flexibility and vendor independence. YANG then enables them to contain each data definition to a module that provides a set of features for extensibility and reuse.1 Together, NETCONF/YANG can allow multiple virtual network operators to independently manage shared resources, perform service and customer provisioning and troubleshooting, while shielding each Virtual Network Operator (VNO) from seeing each other’s configuration or operational data.
Software-defined approaches based on new paradigms such as NETCONF/YANG provide more flexibility and allow the network to be sliced with greater granularity. Nokia has been closely involved in the standardization of this technique through our role within the Broadband Forum (https://www.broadband-forum.org/) and working closely with network operators around the world to determine the most compelling real-world uses for Software-Defined Access Networks (SDAN).
A New Paradigm
Convergence is happening, and success is dependent on an operator’s ability to flex to the new paradigm. Networks need to be highly adaptive to the needs of the services being carried, as well as to the needs of the customers being served, while collaboration and cooperation are key to ensuring cost efficiencies. As demand for network capacity increases, and operators are challenged to maximize the return on their investments, the traditional model of single ownership of the entire physical access network may no longer be optimal.
SDN/NFV can live up to the hype and create an extremely flexible, dynamic, and responsive, network environment that can provide both operational and cost benefits. But achieving this will require that SDN/NFV platforms support multi-vendor models and offers open APIs and standardized protocols for easy integration and flexible programmability in the new emerging SDN/NFV ecosystem.
Nokia is working with providers to understand their requirements, and to ensure future SDANs can support their various use cases through open SDANs. The company is also working with the Broadband Forum and contributing to standardization efforts surrounding new open protocols such as NETCONF/YANG.
1. Network World “Understanding NETCONF and YANG”, January 2014.