5G Transport: From Vision to Reality

Part one in a blog series about how Fujitsu is bringing the 5G vision to life

On the road to 5G, there are a number of different paths that communications service providers (CSPs) can choose. This blog is the first in a series about our vision for the 5G RAN, and how Fujitsu is working with leading CSPs to co-create these networks and bring 5G to life.

Transport is vital for building a robust and reliable network. The xHaul ecosystem consists of the backhaul, midhaul and fronthaul transport segments.  Dedicated dark fiber, WDM and packet technologies are used within these transport segments. As CSPs evolve their networks from 4G / LTE to 5G, there are several options explaining how those transport networks will be designed.

In a “Split Architecture,” the distribution unit (DU) connects to many macro site radio units (RUs) over multiple fronthaul fiber paths. This is a similar architecture to the 4G central RAN (C-RAN) where there is a central point; the DU in this case, fanning out to multiple macro sites for interconnect with the 5G radios, also known as RUs or Transmission Reception Points (TRPs).  This efficient technique is referred to as RAN Pooling, and along with cell site aggregation, offers mobile network operators the ability to engineer the RAN capacity based on clusters of sites coming into the central point DUs, instead of individual cell site demands.

The “Distributed DU” architecture involves DUs collocated with RUs at the cell site.  The distributed DU use case offers a latency sensitive architecture by eliminating the fronthaul transport path.  The fronthaul becomes a local connection between the top and bottom of the tower via fiber cable.  This is a low latency configuration, which also reduces costs by eliminating the fronthaul transport section.  The tradeoff is a loss of multi-site pooling and cell site aggregation with macro cell sites. Moreover, the midhaul capacity is reduced to 10GE rates.

Finally, there is the “Integrated DU” architecture, which integrates the DU into the RU at the cell site.  This architecture offers similar benefits as the Distributed DU use case, but with an additional advantage of lower CapEx and OpEx by combining these devices.   The combined DU and RU reduce the number of devices to install, manage and maintain resulting in expedited service turn-up and faster time to revenue.

To learn more, register for an archived webinar “New Transport Network Architectures for 5G RAN” with Fujitsu and Heavy Reading analyst Gabriel Brown: www.lightreading.com/webinar.asp?webinar_id=1227

About Joe Mocerino

As Principal Solutions Architect, Joe engages wireless and wireline operators and partners in the mobile xHaul ecosystem. His mobile transport expertise includes fronthaul, backhaul, CPRI, packet, OTN, and SONET technologies. Joe has designed, developed, and deployed wireless and wireline transport solutions that maximize capacity and coverage for high-value automated operation. A fan of music and fitness, Joe enjoys playing guitar in his home recording studio and cycling.