While the proposed RIS-aided secure massive MIMO system offers significant advantages in enhancing physical layer security, there are potential drawbacks and limitations to consider in practical deployments:
Hardware Complexity: Implementing a large number of RIS elements and coordinating their phase shifts adds complexity to the hardware design and deployment. Managing the RIS hardware, ensuring synchronization, and addressing calibration issues can be challenging in real-world scenarios.
Energy Consumption: The operation of a massive MIMO system with RIS requires additional energy consumption, especially for powering the RIS elements. Balancing the trade-off between enhanced security and increased energy consumption is crucial for practical deployments.
Cost Considerations: The deployment of a large-scale RIS and massive MIMO infrastructure can be costly, especially in terms of hardware procurement, installation, and maintenance. Cost-effectiveness and scalability need to be carefully evaluated for widespread adoption.
Limited Coverage: The effectiveness of the RIS in enhancing secrecy performance may be limited to specific areas within the coverage area where the RIS can reflect signals. Ensuring seamless coverage and optimizing RIS placement for maximum benefit can be challenging.
Regulatory Compliance: Compliance with regulatory requirements and spectrum allocation policies for deploying RIS-aided systems needs to be considered. Ensuring that the system operates within legal constraints and does not interfere with other wireless services is essential.