• Fronthaul a critical component for the virtual RAN
• Without it, v-RAN becomes significantly less financially advantageous
• Problem could delay full 5G deployment by years

Yesterday we reported on Broadcom (coincidentally thwarted by Trump in its effort to take over Qualcomm) and its launch of a ‘breakthrough’ fronthaul re-purposed Ethernet switch which tapped merchant silicon to provide all the horsepower needed for next  gen front haul without the high ticket prices (condensed version). We wondered out loud about whether there was a standards issue in pursuing this approach. We asked Broadcom about it too: “There’s no indication in the [press] releases that [the front haul switch] is 3GPP-standards compliant. Is it Release-15 compatible, in terms of 5G NR?”  we emailed.

In reply we were told “With Monterey's support for eCPRI, IEEE 802.1CM and CPRI interface specifications, it can connect directly to 5G NR radios as well as LTE radios.” Which, you’ll no doubt have immediately understood, isn’t quite the same thing as being 5G compliant. Anything can be connected to anything else if enough time and money is spent on integration. The real point about full standards compliance is that you have a situation where a component in the chain can fully connect and operate with any other relevant ‘compliant’ device. In this case, a compliant 5G front-end switch should be able to connect to compliant radios from a range of vendors.

Let’s just say there’s almost certainly an issue here and today we got a concise explanation as to why this might be so.

Rethink Technology Research has just completed a research report entitled ‘Virtualized RAN rollouts stutter - awaiting vendor interoperability standards. Cloud RAN deployment forecast 2017-2025,’ a title which neatly sums up the current situation.

As we’ve pointed out before, arguably the most important ‘thing’ about 5G is not the radio tech, but rather the RAN virtualization designed to support, not just the latest and greatest radio like New Radio (NR), but also the existing 3G and LTE radios (LTE will continue on well into the reign of 5G) and variants supporting low latency, IoT and so on. This capability -  variously referred to as virtual RAN, centralised RAN, cloud RAN - is all about separating the signal processing part of the RAN from the radios and antennas at the real ‘edge’ and then aggregating the processing task - virtualizing it. All the usual virtualization benefits flow - lower capital and operational costs, better manageability and agility, less power consumption, lower site costs and so on and so forth. Virtual RAN is clearly the way to go.

But according to the Rethink report, this happy scenario is pretty much a pipe dream.

The fully virtualized Cloud RAN is being held back by a lack of interoperable standards - and for this particular application, interoperable standards are key for obvious reasons.

The knock-on is considerable says Rethink, which calculates that it will take operators ten years to get to full RAN virtualization, once they actually begin doing it. Further delay will put the process back by a few years more.

Rethink is blunt. “Fully virtualized Cloud RAN is being held back mostly by the lack of interoperable standards. The standards that exist, for instance in fronthaul, are controlled by a handful of players who have no vested interest to make them fully interoperable, instead they place proprietary flavours on them, keeping prices high...  Most shipments will not start until this has been ironed out, a process that could take another 3 years before shipments break the 3 million a year barrier.”

Given the central position of v-RANization in the 5G effort, the standards failing in fronthaul must be counted a real blockage to the whole effort.

So back to Broadcom. No, its front haul switch will likely not be 5G standard, at least for a while. But then, neither will anyone else’s.

To buy or see more info on the report click here