As software is incorporated into network technology, its role in efficiently managing the network is expected to grow.

At the ICT Industry Outlook Conference held on the 3rd, Professor Baek Sang-heon of the Department of Electrical and Electronic Engineering/Department of Next-Generation Communications at Korea University presented on software-based future network technology.

'SDN (Software-Defined Networking)' is a networking technology that implements network control with software. In the past, hardware-based switches and routers controlled traffic, but SDN replaces hardware-based control with a software-based SDN controller.

SDN can simplify existing complex processes through programs. Recently, there has been a shift towards placing a type of network OS on top of hardware devices to operate network equipment and manage the network well, and controlling the overall network from that location.

Professor Baek said, “SDN makes it easier to find better routes, allowing for more flexible network management,” and “It will be difficult to apply SDN to a global network, but introducing it to specific areas can lead to efficiency.”

For example, Ericsson, a global mobile communications equipment company, is actively adopting SDN. It calls itself a software company and has been generating revenue from various services derived from hardware for the past 10 years.

Samsung Electronics is also increasing its share of domestic and international software supply. At the last M360, Samsung Electronics President and Network Business Division Head Kim Woo-joon said, “Samsung Electronics has sufficient capacity to stably provide software-based networks,” and is continuously investing in the 5G virtual network sector. In January 2022, Samsung Electronics commercialized a 5G virtual base station in the UK for the first time in Europe, and in February, it completed the launch of a 5G initial network with DISH Network, the fourth largest mobile carrier in the US.

■ Openness-based protocol… Escape from network dependency

An important concept in SDN is the controller. The most representative examples are the open source platform 'Open Daylight (ODL)' adopted in the industry and the 'Open Network OS (ONOS)' used for research purposes. When controlled centrally, availability and scalability are essential to ensure stable operation of the controller.

Recently, a structure has been adopted that allows multiple physical controllers to be integrated into one. If one controller is unavailable, data can be preserved by backing up and replicating information to another controller. Professor Baek said, “Rather than developing a new controller, research has been conducted on borrowing a controller that is suitable for the purpose.”

SDN can solve the problem of network dependency. Previously, there was a problem where the network equipment vendor, not the network owner, owned the equipment rights and became dependent, but through the 'OpenFlow' protocol, a movement has been realized to have the network owners, such as schools, companies, and businesses, have this. The OpenFlow protocol is a standard protocol for communication between SDN controllers and network equipment, and provides functions that improve the flexibility and efficiency of the network.

To this end, in 2021, Intel acquired Barefoot and launched the programmable ASIC 'Tofino' for network switches to support SDN. Recently, it has expanded this to provide a programming chip environment through the 'DPU (Data Processing Unit)' that maximizes data processing performance.

The verification function that preemptively reviews problems that may arise during network operation is also trending toward being implemented in software. 'NFV (Network Functions Virtualization)' is a technology that virtualizes network functions so that they can be run on general servers. Since it can be flexibly managed at a lower cost than before, domestic mobile carriers are also applying it to LTE and 5G networks.

In line with this trend, a paradigm shift in IT companies to telecommunications service providers is also predicted. Professor Baek predicted, “While telecommunications service providers (telcos) are changing the paradigm to lead IT services such as AI, in the future, IT big tech companies will also be able to perform the work of telecommunications service providers through software.”

Software companies such as VMware are implementing network verification-related functions. In addition, Microsoft (MS) announced that it would acquire a company called Affirmed Network and provide software implementations of 5G network functions, and is currently providing them to AT&T, a U.S. telecommunications company.

■ Acceleration of base station software… Open LAN technology in the spotlight

Professor Baek pointed out that one of the important trends is that base station equipment is gradually becoming software-based. By separating the functions of the base station into radio units (RUs), distributed units (DUs), and central units (CUs), the models implemented in existing hardware are implemented in software on general servers. Functions can be managed as traffic increases and decreases at each stage, securing flexibility in resources.

Recently, Open RAN technology, which opens and standardizes the hardware and software of radio access networks (RAN), is attracting attention. To intelligently control RAN, it follows the open interface of the devices below the controller.

While existing RANs required the use of hardware and software from specific manufacturers, Open RAN allows hardware and software from various manufacturers to be mixed and used, thereby expanding the flexibility and choice of networks. When SDN technology, which implements network control through software, is combined with Open RAN technology, networks are expected to become more flexible and efficient, and to be able to respond quickly to new applications and services.

Professor Baek said, “If open source-based open LAN becomes active, a competitive structure is expected between each equipment manufacturer and the software companies that apply it,” and “Efforts by companies to foster an open ecosystem are continuing.”