SK Telecom and Nokia have implemented what they claim is the world’s first cloud-based SDRAN (Software-Defined RAN) - also known as Cloud RAN - in a commercial network. SDRAN is a next-generation cloud-based radio access network and cloud base station equipped with various IT technologies based on open architecture.
It is a new concept in technology in the sense that mobile communication functions are turned into virtual machines (VM) to be implemented on general-purpose servers, and integrated within the cloud.
SDRAN enables traditional base station functions to be implemented on a general-purpose IT server, and its distinctive features include functional split between real time and non-real time processing functions, Ethernet-based interface, and intelligent operation.
A functional split of the protocol in the baseband processing is the architecture of SDRAN, and this relegates parts of the DU (Digital Unit) functions to the RRU (Remote Radio Unit). By doing so, traffic can be scaled more effectively and multiple connectivity scenarios can be efficiently deployed without immediate additional investments in transport or baseband capacity.
Until now, a designated interface has been used for data transmission between the DU and the RRU, but with the new SDRAN, a more broadly used Ethernet-based DU-RU interface is optimised for the communication environment and used for more efficient network configuration.
The interface also better handles signal delays, 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.
By applying general IT technologies to an interface as well as base station processing, the new technology is expected to accelerate 5G network innovation that evolves beyond All IP toward All IT.
Particularly, VU functions are applied for intelligent operation, which are used in IT virtualisation (e.g. data centre). By doing so, a base station can self-detect systemic errors and automatically restore the VM.
Also, it dynamically generates or deletes the virtual resources of a base station, depending on the number of current users and traffic loads, for more efficient resource allocation. And service quality is also likely to improve due to more stable network operation.
SDRAN will be able to offer a variety of third party edge services in connection with MEC (Mobile Edge Computing) that provide localised communication services. And, since the network is implemented by software, it is easier and quicker to add new network functions. This would significantly shorten the time for delivering new technologies to customers.
As network virtualisation receives growing attention in the telecommunication industry, commercialisation of SDRAN is seen as an excellent achievement to overcome the technical difficulty of virtualising a base station that emphasises high-speed data processing without delay. This would play an important role in an evolution toward next-generation communication network.
Frank Weyerich, head of Mobile Networks products at Nokia said: “This is a major milestone for Nokia; together with SK Telecom, we have for the first time implemented our AirScale Cloud RAN technology in a commercial network.
“We are paving the way towards 5G, and cloud-based radio networks delivering the scalability and flexibility required to allow operators such as SK Telecom to meet the future data demands of customers, enabling new levels of user experience at minimal cost and maximum operational efficiency.”
“Network innovation through convergence of telecommunication and IT is an urgent task to deal with explosive growth of data traffic. SK Telecom will continue to develop innovative technologies like SDRAN to lead the evolution toward next-generation network,” said Park Jin-hyo, Senior Vice President and Head of Network R&D Centre at SK Telecom.
Last year, SK Teelcom completed a field test of SDRAN, and recently succeeded in applying the technology to the commercial network. It said that by commercialising the virtual core network and SDRAN, the company is now in an advantageous position in accomplishing the world’s first virtualisation of an entire LTE network, as well as innovation of 5G network structure.