cloud radio access network (C-RAN)

C-RAN (cloud radio access network) is a centralized, cloud computing-based architecture for radio access networks (RAN) that enables large-scale deployment, collaborative radio technology support, and real-time virtualization capabilities. It is an evolution of the current wireless communication system and uses the latest common public radio interface (CPRI) standard, coarse or dense wavelength division multiplexing (CWDM / DWDM) technology and millimeter wave (MM wave) transmission for long distance signals. The "C" in C-RAN can alternatively stand for centralized or collaborative.

A RAN establishes a connection or communication between base stations and end users. In the C-RAN architecture, baseband units (BBU) are relocated from individual base stations to a centralized control and processing station, often referred to as a BBU hotel. The BBU hotel connects to the network using high-speed optical fiber and maximizes the distance between cells. This type of cloud computing environment is built on open hardware and interface cards that dynamically handle fiber links and interconnections within the station.

C-RANs are significant in the future progression of wireless technology, such as 5G and the IoT. With easier deployment and scaling capability, the transition from LTE to 5G networks will rely heavily on C-RAN development. It also provides a cost-effective, manageable solution for supporting more users.

Cloud RAN (C-RAN)

Components of C-RAN

C-RAN networks are made up of three primary components:

  1. A BBU hotel or pool: a centralized site that functions as a  data or processing center. Individual units can be stacked together without direct linkage or interconnected to allocate resources based on network needs dynamically. Communication between units has high bandwidth and low latency.
  2. An RRU network: the traditionally used network to connect wireless devices to access points.
  3. fronthaul or transport network: the connection layer between a baseband unit and a set of RRUs using optical fiber, cellular or millimeter wave communication.

Advantages of C-RAN

  • Produces higher spectrum efficiency.
  • Is more cost and footprint effective due to less hardware.
  • Has lower heating, cooling and power requirements.
  • Creates a more simplified, scalable and flexible network.
  • Supports a larger number of mobile users and wireless standards.
  • Allows for more efficient network upgrades, enhancements, testing, monitoring, and maintenance.
  • Has the ability to pool resources or reuse infrastructure.
  • Achieves faster speeds than distributed RANs.
  • Uses cloud computing open platforms and real-time virtualization to allocate shared resources between BBUs dynamically.
This was last updated in January 2019

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