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Nothing ethereal about this Cloud RAN achievement with <br/> SK Telecom

Twitter: @annapietil

The latest in our blog series on Nokia AirScale Radio Access looks at how AirScale Cloud RAN can bridge long distances with great KPIs.


Ever wondered how Ethernet got its name? Ethernet is named after the ‘luminiferous ether’, a 19th century concept of an invisible medium that’s everywhere and carries light over great distances. The name lingers, describing today’s common protocol.

Nokia Cloud RAN recently reached another milestone, bridging a lengthy 350 km distance on the midhaul interface between the radio access point and an AirFrame Data Center over Ethernet. The deployment by Korea’s SK Telecom showed no performance degradation over the 350 km link and all key performance indicators (KPIs), remained at the same excellent level as previously tested over short distances. Even the latency, which increases with distance, did not affect the cloud base station performance. Typically, signals travel 100 km in 1 ms even in optical.

The key to bridging the 350 km distance is to introduce a functional split between real-time (RT) and non-real-time (NRT) traffic to allow time-critical functions to be processed at the cell site, while the centralized data center performs non-real-time functions. The split means much longer backhaul latency can be tolerated. This permits the use of Ethernet, which handles signal delays better, so that when a delay occurs, it adjusts the timing of data transmission and prevents a slowdown in transmission speed. Accordingly, customers benefit from better data quality.

As Mr. Jinhyo Park, SVP, Head of N/W R&D Center of SK Telecom explains: “Our experience shows that the Cloud RAN KPI values are equivalent to a legacy LTE network. This was the first bridging of such a long a distance, 350km, with Cloud RAN and the Cloud BTS protocol stack being split. Cloud-based radio networks deliver the scalability and flexibility we need to meet the future data demands of our customers, and enable new levels of experience and maximum operational efficiency, paving the way to 5G.”

The achievement follows SK Telecom’s deployment in September 2016 of the world´s first Cloud RAN deployment in a commercial network using our AirScale Cloud Base Station.

And just to clarify what we mean by fronthaul and midhaul here, they are all about connecting the components of Cloud RAN. Fronthaul describes the connection between the System Module and RRH (remote radio head), while midhaul refers to the connection between the System Module and AirFrame Data Center server.

Cloud RAN brings centralization benefits while supporting relaxed transport requirements (that is to allow longer latency) thus allowing CSPs to re-use existing transport assets in their LTE networks. This is crucial for many CSPs as they seek to achieve real Cloud RAN savings by cost-effectively scaling HetNet and IoT capacity from centralized data centers without the need for macro site visits. Transport costs are optimized and control plane capacity scaling is achieved efficiently in the cloud.

Where the luminiferous ether carried light over long distances, the Nokia Cloud RAN with the innovative functional split carries our mobile communications wherever we need them.

You're welcome to download this Cloud RAN whitepaper: Multi-layer and cloud-ready radio evolution towards 5G  and our handy infographic.

Also tune in to listen to our on-demand webinars:

Share your thoughts on this topic by replying below – or join the Twitter discussion with @nokianetworks using #cloud #telcocloud

Anna-Kaarina Pietilä

About Anna-Kaarina Pietilä

Anna-Kaarina Pietilä is responsible for AirScale and AirScale Cloud RAN at Nokia. She enjoys writing blogs about these solutions and about innovative, high-quality software which improve smartphone experience and network capacity. She holds an MA from Åbo Akademi University and University of Turku and is based in Finland.

Tweet me at @annapietil

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