Ensuring 5G’s fiber foundation

Previously published on RCRWireless

As carriers lay the groundwork for transforming their current networks to 5G, they face challenging – and sometimes conflicting – demands ahead.

5G is expected to have attributes that include:

• High-bandwidth applications such as fiber replacement, which carriers like Verizon are currently exploring with fixed wireless at 28 GHz.
• Low-latency and high-reliability for mission-critical communications, with latency on the order of 1 millisecond and 7-10s reliability – which means approximately 3 seconds of downtime per year.
• Support for massive numbers of internet of things devices.

In traditional, hardware-based networks, these contradictory requirements would be all but impossible to meet with a single network architecture.

But in next-generation networks, operators will be able to leverage the concept of network slicing. Network slicing allows users or devices of a particular type to be grouped into a network that feels like an independent network from the end user perspective, but in fact uses shared resources of network infrastructure and sits alongside other “slices” that are optimized for their respective service demands.

The physical network transformation toward 5G is already beginning, as mobile network operators boost their capabilities with more fiber and a new centralized Radio Access Network architecture as part of expanding small cell deployments. The next logical step toward 5G network formation is a cloud-RAN approach, combined with network virtualization and increased automation. In this way, complex networks made up of hundreds or potentially thousands of network slices can be properly resourced and managed. Mobile edge computing is also expected to take on a larger role, so that network processing can be distributed closer to the end user in order to reduce system latency. Inter-data center links are already moving to 100G speeds in order to support this network vision.

Achieving this new network paradigm requires more robust and careful attention to testing and monitoring to assure a future-proof network for the physical layer now being laid for 5G. MNOs have gained some experience in fiber installation with the use of remote radio heads at the top of cellular towers connected to baseband units at the tower base. But with centralized RAN deployments, fronthaul fiber connections can run as far as 15 to 20 kilometers in order to connect baseband units and remote units. The distance means the insertion of active and passive optical devices and more optical connections that can introduce attenuation, jitter and overall latency unless fiber runs are scrupulously well-installed. Fronthaul also requires high throughput in order to support fast end-user speeds: typically, fronthaul must support 16 times higher speeds than that which the MNO desires to deliver to the end consumer. Complicating this requirement is the fact that dispersion begins to affect the accuracy of received transmissions above 10 gigabits per second in an optical fiber environment.

With fiber-based network quality demands rising at both the edge and in inter-data center communications, EXFO is leading the industry in the ability to test, monitor and analyze the physical foundations being laid for 5G transformation.

Cost-effective, first-time-right fiber installation is supported by EXFO’s TestFlow field process automation and analytics platform, which allows project managers to see in real-time what multiple installment teams are doing on-site and run analytics to ensure efficient, compliant and high-quality fiber deployment. Meanwhile, EXFO’s Xtract platform for “3D” service assurance analytics collects, assesses and correlates information from the pure optical level, the IP transport network and the fixed or mobile service layer. While other players focus only on services and traffic flow, EXFO integrates visibility to the physical layer as well, for the deepest intelligent insights.

Fiber network quality is crucial to future 5G networks. EXFO enables visibility into the complex physical and virtualized assets that will enable mobile network operators to move forward to 5G.