Sign in Subscribe

What is the function of the Remote Radio Unit (RRU) in Ericsson 5G deployment?

Last updated on 


The Remote Radio Unit (RRU) is a critical component in the deployment of 5G networks, including those by Ericsson. Its primary function is to enhance the radio signal transmission and reception between the user devices and the baseband unit (BBU) or central processing unit. Let's delve into the technical details of the RRU in the context of Ericsson's 5G deployment:

  1. Radio Frequency (RF) Signal Processing:
    • The RRU is responsible for processing radio frequency signals, which include both the uplink signals from user devices and the downlink signals from the BBU.
    • It performs tasks such as modulation, demodulation, amplification, and filtering to ensure efficient and reliable transmission of data over the air interface.
  2. Frequency Bands and Carrier Aggregation:
    • 5G networks often utilize multiple frequency bands to achieve higher data rates and better coverage. The RRU is designed to support carrier aggregation, enabling the aggregation of multiple carriers from different frequency bands to increase the overall bandwidth.
    • Ericsson's 5G RRUs are typically configured to operate in various frequency ranges, including Sub-6 GHz and millimeter-wave (mmWave) bands.
  3. Massive MIMO (Multiple Input Multiple Output):
    • Massive MIMO technology is a key feature of 5G, enhancing spectral efficiency and increasing network capacity. The RRU is equipped with multiple antenna elements, allowing it to simultaneously transmit and receive signals to and from multiple user devices.
    • Massive MIMO also enables beamforming, where the RRU focuses the signal in the direction of specific users, improving signal quality and reducing interference.
  4. Digital and Analog Signal Processing:
    • The RRU incorporates both digital and analog signal processing components. Digital signal processing is employed for tasks like baseband processing, while analog components handle the RF signal amplification and modulation/demodulation.
  5. Front-Haul Connectivity:
    • The RRU is connected to the BBU via a high-capacity front-haul link. This link carries digitized and processed data between the RRU and BBU, enabling centralized processing and coordination of multiple RRUs in a network.
    • Ericsson's deployment may involve optical fiber or other high-speed connectivity solutions for efficient front-haul communication.
  6. Energy Efficiency:
    • Ericsson focuses on designing energy-efficient RRUs to minimize the environmental impact and operational costs. This involves optimizing power consumption during both idle and active states.
  7. Advanced Antenna Technologies:
    • Ericsson's RRUs may incorporate advanced antenna technologies, such as adaptive beamforming and beam-steering, to dynamically adjust the antenna patterns based on the location and movement of user devices.