Strange as it might seem, Huawei’s international tribulations may bear some responsibility for the growing interest in a more open radio access network (RAN).
As security hysteria drives countries to excommunicate the once-indomitable Chinese company, telecom operators are left with fewer alternatives than ever before. Their dependence on a shrinking number of industry titans has made them push even harder for more “open” technologies — and especially for a radio access network (RAN) without a dominant supplier.
But, rehousing the baseband in centralized facilities could bring benefits in the future. Moving network functions into those centralized baseband units is far from straightforward, largely because of the increased fronthaul distance. This “functional split,” determining which functions go into baseband and which should be done at the radio site, has been at the crux of the open RAN debate. After considering a menu of splits, standards bodies like the European Telecommunications Standards Institute (ETSI) and the 3rd Generation Partnership Project (3GPP) had settled on two, according to John Baker, senior vice president of business development for Mavenir, a software company hoping to profit from a more open RAN. At opposite ends of the split spectrum, each had its pros and cons. (See Is vRAN Still Too Hot to Handle?)
The first, Option 2, would push many of the network functions into the radio unit. While this higher-layer split might help to reduce transport costs, it could also increase the signaling delay, making it unsuitable for latency-sensitive applications such as gaming and virtual reality. With Option 7, the lower-layer split under serious consideration, nearly all functions would shift into the baseband. That should assist with resource allocation to users, and boost performance, but it would also put more pressure on the fronthaul.
The most ardent supporters of open RAN saw reasons to favor Option 7, according to Baker. By leaving hardly any functionality in the radios, this would simplify the hardware requirements and help cultivate a market for “white box” radios — a standardized kit that operators could buy “off the shelf,” like tools at a DIY store. Option 2, by contrast, seemed to reinforce the vendor lock-in. “It puts a lot of functionality into the radios and so they are still proprietary,” says Baker.