Optical networking suppliers have seized 5G as a catalyst for future growth, and for good reason. Promised 5G wireless data speeds of 10x 4G rates will require deep fiber architectures that push fiber cables and optical equipment closer to wireless subscribers than ever before. Additionally, the wireline access functionality must be put in place before operators' 5G networks are turned on at scale -- putting pressure on operators to resolve their access network issues sooner rather than later. The increasingly aggressive and ambitious 5G plans being announced by Tier 1 operators must undoubtedly be causing high anxiety among network planners charged with turning these pronouncements into commercial reality.

As we have noted in recent blogs, architectural implications for the 5G RAN are great and there are many potential options. The centralized RAN (CRAN) architecture has been proposed to efficiently scale networks for 5G demands by removing baseband unit (BBU) processing out of individual cell sites and centrally pooling BBU capacity in central offices. Some operators, including Verizon, have already started building CRANs for their 4G networks.

CRANs introduce a new physical network challenge that does not exist in traditional distributed RANs: How do you efficiently connect the remote radio head to the BBU pool? CRAN terminology labels this RRH to BBU connection as the fronthaul network. Industry consensus is that fiber is the only option. However, should this fronthaul network be a bunch of dark fibers? Or is WDM more efficient? If WDM is preferred, should these be passive pluggable WDM connections or active DWDM at either end? PON is another option for fronthaul connectivity but, here too, there are several options, including asymmetrical 10G PON, symmetrical 10G PON (XGS PON) and TWDM option NGPON2.

Learn how SDN-based automation will play a key role in the future of optical networking. Join us in Austin at the fifth-annual Big Communications Event May 14-16. BCE brings you face-to-face with hundreds of speakers and thousands of industry thought leaders. There's still time to register and communications service providers get in free!

Verizon is one of the world's early adopters of CRAN. At BCE, Verizon's Glenn Wellbrock will discuss the operator's CRAN network architecture, technology options behind CRAN and pros and cons of the various options available.

Wellbrock will be joined by representatives from equipment suppliers Ericsson and Huawei and fiber infrastructure supplier Clearfield in a wider discussion of the future of 5G transport -- including the entire access and aggregation networks supporting 5G. With the stakes so high for network operators and with so much to be decided over the next two years, the panel promises to deliver a lively and informative debate.

— Sterling Perrin, Principal Analyst, Heavy Reading