Top executives from several leading telecom and enterprise companies gathered last week at the IEEE 5G World Forum to discuss the industry’s fronthaul problem: how to connect, in practical ways, radio heads and antenna complexes in cellular networks to remote baseband units.
Led by Helen Ojha of Collinear, a company seeking to solve this fronthaul problem, the panel, which was held on July 10, 2018 and included executives from Facebook, Vodafone, Nokia, and Aviat, concluded that new RAN functional split architectures and advances in wireless transport technology provide “good enough” practical solutions. With this breakthrough, the benefits of centralized RAN can be available in fiber-poor and fiber-rich areas alike.
Panel members, Dr. Stanley Chia, CTO of Tomorrow Street, a joint venture of Vodafone Procurement Company and the Luxembourg Government; Renuka Bhalerao, Manager at Facebook and Technical Committee Member at the Telecom Infra Project (TIP); Gary Croke, Senior Director of Marketing and Strategy at Aviat; and Dr. Ajay Rajkumar, Consulting Engagement Leader at Nokia Bell Labs, debated the practicalities of “ideal” versus “non-ideal” fronthaul transport, concluding that “ideal” fronthaul, as defined for 4G backhaul by 3GPP, is only practical for a limited few geographies and markets around the world. This limitation is due to the very high capacity requirement of 10Gbps or greater, depending on the antenna system, and the stringent latency one-way requirement of 2.5microseconds of “ideal” backhaul versus “non-deal” backhaul ranging from 10Mbps to 10Gbps and 2 – 60 milliseconds.
Lively discussion ensued engaging the panelists and the audience on the topics of the subjective nature of latency as experienced by end users, the practicalities of reaching diverse end-points in urban areas working with street furniture and its various owners, and the competitive implications of open interfaces and open standards for the new split RAN architectures. To handle the capacity and latency requirements of different scenarios and use-cases for 5G, the panel considered a wide range of alternatives that are in development, including network slicing, edge computing, the need to leverage existing networks infrastructure, and use of higher capacity millimeter wave and near-infrared frequencies for transport. Open interfaces and disaggregated multi-vendor solutions were debated with a compelling case made for these to accelerate competitive pursuit of new 5G infrastructure through cost-reducing innovations.
The new course for the industry as it approaches 5G ranges from new network edges composed of IoT gateway devices that seek access to the public cellular networks, private cloud and enterprise networks intersecting public networks, to scenarios and use-cases driven vRAN deployments variously utilizing the 3GPP split options. The panel concluded that the industry is driven by cost considerations, practicalities and a growing realization of the need for greater transparency into the workings of network infrastructures. As a final note, Ms. Bhalerao encouraged all attendees to watch for the results of TIP-sponsored non-ideal vRAN transport tests now underway in several operator-sponsored labs around the world, to be reported on in upcoming TIP Summit taking place in London this October 2018.