CRAN (Cloud RAN): Advantages and Disadvantages

This page explores the benefits and drawbacks of CRAN (Cloud RAN) technology.

What is CRAN (Cloud RAN)?

Introduction:

• CRAN stands for Cloud Radio Access Network.
• Traditional network management and monitoring of distributed sites was complex. C-RAN addresses this by enabling centralized site management and monitoring.
• CRAN requires less equipment, saving space, energy, and rental costs.
• It improves operational efficiency.

Figure 1: Cloud RAN Architecture

The figure above depicts the architecture of a Cloud RAN, or centralized RAN. Instead of individual Baseband Units (BBUs) at each distributed location as in traditional RAN, CRAN employs one centralized BBU (C-BBU). This C-BBU interfaces with distributed Remote Radio Heads (RRHs) using the CPRI interface. The C-BBU connects to the IP Aggregation (IPAG) network via an optical link.

This architecture is centralized and cloud computing-based, supporting multiple wireless standards like 3G, 3G, and 4G. Its features, including clean operation, centralized processing, collaborative radio, and real-time capabilities, have led to it being known as C-RAN. It is also referred to as centralized RAN.

For more in-depth information, refer to the difference between traditional RAN vs cloud RAN.

Benefits or Advantages of CRAN (Cloud RAN)

The following are the benefits of using Cloud RAN:

• Fast Deployment: Requires less civil work due to reduced equipment.
• Enhanced Capacity and Coverage: Provides improved network performance.
• Self-Optimization: Can be easily self-optimized, self-configured, and self-adaptable using SDN/NFV as needed.
• Reduced Operational Costs: Lower energy consumption and rental savings due to fewer equipment installations.
• Improved Network Security: Centralized network access limits vulnerabilities.
• Optimized CAPEX and OPEX: Reduces both capital and operational expenditures for network operators.
• Concise Network Topology: Offers a cleaner network structure, enabling smooth evolution.
• Reduced Interference: Minimizes cell interference, improving the overall user experience.

Drawbacks or Disadvantages of CRAN (Cloud RAN)

The following are the drawbacks of using Cloud RAN:

• High Fronthaul Capacity: Requires high fronthaul capacities to handle higher bandwidth requirements between BBUs and RRUs. Optical fiber is often necessary to meet these demands.
• BBU Cooperation Challenges: Requires BBU cooperation for user data sharing, scheduling, and channel feedback collection. Standardized methods for addressing user privacy, low latency, and high-bandwidth communication between BBUs are still evolving.
• Centralized BBU Limitations: One centralized BBU must support a large number of channels while maintaining minimal fronthaul delay and overhead.