What Is Radio Access Network (RAN) in 5G?

As we usher in the era of 5G, the Radio Access Network (RAN) emerges as a pivotal enabler of this next-generation wireless communications revolution. RAN is the heart of connectivity, bridging the chasm between myriad devices and the core network, and it is vital to unlocking the transformative potential 5G promises—lightning-fast speeds, near-zero latency, and ubiquitous coverage. This article aims to reveal the role of RAN in 5G networks, clarify its operating principles and advantages, and help us better understand how RAN is at the forefront of promoting a hyper-connected future.

What Is Radio Access Network?

A RAN is a telecommunications system segment connecting individual devices, such as smartphones, laptops, and IoT gadgets, to other parts of a network through radio connections. RAN is a critical element in the architecture of mobile telecommunication systems, serving as the conduit for transferring information between the user equipment (UE) and the core network. This network component is synonymous with providing the necessary infrastructure needed for wireless communication in various environments, including dense urban areas, suburban locales, and remote rural regions.

Which Parts Constitute a RAN in 5G?

Unlike 4G, the 5G RAN comprises antennas, a Remote Radio Unit (RRU), and a Baseband Unit (BBU). Rather, it is rebuilt into three operational units, designated as Centralized Unit (CU), Active Antenna Unit (AAU), and Distribute Unit (DU):

CU: CU is in charge of tasks that need information aggregation and little real-time demands. It also supports protocols at higher layers of the stack, including RRC, PDCP, and SDAP.

AAU: AAU is a wireless communication device that integrates RRU function and antenna array. It is used to process the transmission and reception of wireless signals at the same time. Due to the integrated hardware, it can simplify the base station architecture and improve signal processing efficiency.

DU: DU supports the bottom layers of the protocol stack, including the MAC, RLC, and physical layer, and is in charge of autonomous, demanding tasks that must be completed in real time. The CU regulates the operation of this logical node, which comprises a subset of eNB/gNB functions based on the function splitting option.

How Does RAN Work?

The radio access network is a key component of the mobile communication system and is responsible for managing the wireless link between user equipment and the network. In RAN, the RRU plays a vital role. It is connected directly to the antenna and is responsible for sending, receiving and converting digital radio signals. After receiving the signal, the RU communicates with the BBU through the Common Public Radio Interface (CPRI). The BBU further processes the signal to ensure that the information can smoothly enter the core network, where necessary scheduling and management are performed. Like blood, data flows forward or back to the user through this transmission mechanism, completing the process of calls and data exchange.

What Are the Wireless Technologies and Advantages of RAN?

In 5G RAN, several key wireless technologies support the high speed, large capacity and low latency of 5G networks. Let us take a look at the important technologies in 5G RAN.

• Massive MIMO (Massive Multiple Input Multiple Output): It may serve more users concurrently by installing a large number of antennas (sometimes dozens or even hundreds) on base stations, greatly increasing spectral efficiency and network capacity.

• Beamforming: This is a technology for signal processing that focuses wireless communications into "beams" that are aimed at particular people or objects. Beamforming and massive MIMO together can significantly increase transmission range and signal quality in 5G.

  

• Network Slicing: Although not a pure wireless technology, network slicing allows operators to provide virtual network architecture to meet the special needs of different user groups, such as different speeds, capacities, number of connections, delays, etc.

• Ultra Dense Networks (UDN): 5G uses a denser base station layout than 4G. The large deployment of small base stations can improve coverage and capacity, and is especially suitable for densely populated urban environments.

These technologies cooperate to form the technical foundation of 5G RAN, enabling 5G networks to support a large number of user devices and provide services for various applications, such as enhanced mobile broadband (eMBB) and massive machine-type communications (mMTC). and ultra-reliable low-latency communications (URLLC).

As the backbone of 5G, the Radio Access Network not only enhances user experiences through improved broadband and connectivity solutions but also opens up a wealth of possibilities for industry-wide innovation, such as smart cities, autonomous vehicles, and the Internet of Things (IoT). With its advanced capabilities, the RAN stands central to realizing the full vision of a hyper-connected future where seamless and robust communication is a foregone conclusion, marking a significant leap forward in our journey towards an interconnected world. If you want to know more about wireless access network solutions, you can contact us through FS.com and we will customize the solution that best suits you.