Testing the varied elements of Open Radio Entry Networks—the open management unit, distributed unit and radio unit, or O-CU, O-DU and O-RU—has been the focus of a number of plugfests and different in depth testing as operators, distributors and check corporations work out the intricacies of interoperability, specification conformance and numerous options in multi-vendor O-RAN environments.
Indicators Analysis Group just lately took Open RUs and DUs to the lab and examined their efficiency below totally different, simulated radio circumstances, utilizing check instruments from Spirent Communications.
“The scope of this research was significantly distinctive within the context of Open RAN testing, which has traditionally targeted on compliance or in some circumstances vitality effectivity,” SRG stated in an accompanying report based mostly on the testing. “It’s all effective and good to have multi-vendor assessments to display totally different radio elements can ‘discuss’ with one another and even set up a voice/information name. Nevertheless, that functionality is desk stakes in at the moment’s setting. Cell operators need networks that not solely work however which work nicely by delivering good person information speeds with life like/difficult circumstances and which may scale by supporting a considerable amount of information site visitors in essentially the most environment friendly means doable.”
“To get to the following section [of Open RAN], we have to concentrate on a brand new set of metrics, to essentially show that the know-how is prepared for scale, and wide-scale adoption,” stated Spirent’s Anil Kollipara, VP of product administration for check and automation, throughout a session at Open RAN World Discussion board discussing the DU check outcomes with SRG President Michael Thelander.
What did SRG check?
The corporate examined two Open RAN distributed models (O-DUs) and accompanying management models (CUs) at a Spirent facility in Texas, and three Open RAN RU reference platforms at Spirent’s amenities in New Jersey.
What kind of assessments had been performed?
The assessments included emulation of a number of UEs interacting with the DUs and RUs by way of uplink and downlink testing below ultimate/static radio circumstances, in addition to uplink obtain sensitivity assessments and a “multitude” of fading channel situations (utilizing situations specified by 3GPP) within the uplink and downlink, together with simulation of motion from strolling to driving at freeway speeds.
“We wish to actually perceive how these totally different vendor implementations carry out below these real-world circumstances,” stated Kollipara.
What had been the outcomes?
Beneath favorable RF circumstances, SRG stated, “there weren’t any significant differ-
ences in efficiency.” That modified, nevertheless, with more difficult radio circumstances.
SRG’s outcomes point out some fairly stark efficiency variations between totally different vendor implementations of Open RAN RUs and DUs (and companion CUs). However the efficiency variations weren’t so simple as, one vendor carried out higher than one other—it was extra a scenario of, the distributors carried out higher than each other below particular community circumstances.
For instance: Whereas the precise distributors weren’t named, SRG discovered there was a 27-28% distinction in “goodput” efficiency (or the measured throughput adjusted for the related bit error fee) between the 2 DU platforms—however each carried out higher below totally different circumstances. In near-cell circumstances with little path loss, the “Platform A” carried out 28% higher than Platform B; on the cell edge, “Platform B” carried out 27% higher than Platform A, together with having the ability to higher keep protection/connections with the UEs, regardless of extra path loss, in line with Thelander. That implies the platform from the primary vendor is extra optimized for enhanced cellular broadband use, Thelander stated, whereas the second platform is arguably extra optimized for an IoT-type deployment. These can be essential concerns for any operator weighing its Open RAN choices.
SRG discovered that within the RU testing, in the meantime, the variations within the obtain sensitivity among the many three RUs ranged from excessive single-digits to low double-digits of dB, whereas variations in “goodput” ranged from the mid-to-high double digits, and even triple digits, throughout the varied fading situations. That has direct implications for deployment. “This distinction in sensitivity may translate to double the cell radius or 4 instances the cell dimension,” SRG identified, including that the end result additionally “signifies there are RUs available on the market at the moment which might be Open RAN compliant however on no account worthy of deploying in a industrial community, even when they’re given away.”
What are the implications?
SRG famous in its report that sizable performances variations are to be anticipated throughout the Open RAN ecosystem, which was meant to place new community gear and software program distributors in play—so it shouldn’t be a shock that testing can reveal variations amongst such distributors, or variations between new gamers and established NEMs who’ve additionally embraced Open RAN.
As SRG identified, the efficiency and protection metrics that an Open RAN platform can obtain, decide the cell dimension that an operator can reliably plan for, and closely affect the client expertise. And if obtainable Open RAN platforms can ship efficiency solely below optimum circumstances or within the lab, however falter in real-world efficiency testing, that’s an existential downside for Open RAN.
“On the finish of the day, what actually issues is, are you able to deploy an answer that delivers on its guarantees?” Thelander stated within the Open RAN World Discussion board session. What SRG testing illuminated, then, was the “stark variations” within the capabilities of Open RAN RUs and DUs supply below the identical community situations.
Extra data obtainable from Indicators Analysis Group right here, and you’ll watch the Open RAN World Discussion board Session on-demand right here.
