To meet the throughput and varied requirements of 5G mobile networks, centralized and virtualized radio access network (cRAN and vRAN) are considered instrumental to create a cost-effective yet flexible network. However, RAN centralization imposes stringent requirements on the transport or fronthaul network. That’s why new transport protocols based on different functional splits between the centralized and distributed units have been proposed by various industry groups to mitigate this.
In addition, today’s 4G or LTE networks still have a lot of life left in them and many mobile network operators (MNOs) are still in the process of recouping their return on investment (ROI) on such networks. Yet, once again, they are under pressure to build out another network – with new base stations and remote radio units - which means increased financial investment.
This is where the question lies. How can MNOs advance 5G network buildout while leveraging existing infrastructure and enabling a faster ROI?
The answer is very clear. Mobile networks must be re-architected. Just as virtualization modernized the core, the fronthaul or the edge needs to undergo the same transformation.
Interoperability and Flexibility are Essential in the Next Generation Fronthaul
Intel® Network Builders ecosystem partners are at the forefront of the 5G and vRAN revolution. By decoupling hardware from software, radio functions are able to run on commercial of-the-shelf (COTS) servers on premise or in the Cloud to reduce costs, improve interoperability and reduce time to market for MNOs. However, the connection between the different vendor-proprietary components of the RAN, also known as the fronthaul, still remains static and hardware-dependent. Extending virtualization to the fronthaul network unleashes the true potential of vRAN.
The next generation fronthaul network must be able to:
1) Adapt to different fronthaul capacity requirements:
The traditional two-tier fronthaul architecture which employs a fixed point-to-point connection between the Baseband Unit (BBU) and the Remote Radio Unit (RRU) is no longer a practical option to support the diverse applications of 5G. Different criteria have to be considered in order to select the most appropriate functional split for the intended 5G application. To enable this, an additional tier that sits between the BBU and RRU can be added to provide a multipoint-to-multipoint network. With this, mobile network operators have the flexibility to adapt to different functional splits based on the application. For example, a high functional split can be chosen if high bandwidth is required for a particular application, and a low functional split can be utilized if low latency is required.
2) Enable interoperability between different RAN components:
In addition, RAN components must be interoperable between different vendors. This way, MNOs can create a radio access network that is composed of the best of breed components from a more competitive and innovative ecosystem. This effectively means that the baseband units and remote radio units can be from any vendor and be formed into an interoperable RAN network, eliminating reliance on a single vendor.
More than that, mobile network operators can now add on 5G RAN components over their existing 2G, 3G and 4G infrastructure. By enabling interoperability between new entrants and existing vendors, MNOs can maximize investment protection while enabling a seamless cost effective migration to 5G.
Network Edge Transformation is Imperative
The Dali Virtual Fronthaul Interface (vFI™) provides the fronthaul interface between the Virtualized Baseband Unit (vBBU) which are based on Intel® Xeon® Scalable processors and Remote Radio Units (RRU) at the edge. By implementing advanced radio signal routing, aggregation and translation capabilities to the fronthaul network, Dali vFI enables shared infrastructure, dynamic capacity allocation, and more importantly, an open RAN.
By enabling interoperability between new vRAN entrant vendors that leverages SDN and NFV, and historically deployed RAN elements, Dali vFI effectively enables a cost-effective and backward compatible solution for MNOs and enables network modernization without incurring the step function cost of rip-and-replace.
With Intel x86 processors and integrated FPGA resources, vFI can support legacy and new fronthaul protocols based on low and high functional split. This capability not only enables more flexibility in the location of the baseband resources, but it also supports the various deployment scenarios of 5G including low latency applications and massive MIMO.
Dali Wireless strongly believes that the edge is where the next step for innovation in the RAN will happen to enable all the promised 5G applications. Being a part of the Intel Network Builders program and the Intel Network Builders Edge ecosystem, Dali Wireless can effectively collaborate with other ecosystem partners to innovate and support the industry through transformation of the network edge.