Drone Small Cells in the Clouds: Design, Deployment and Performance Analysis (1509.01655v1)

Abstract: The use of drone small cells (DSCs) which are aerial wireless base stations that can be mounted on flying devices such as unmanned aerial vehicles (UAVs), is emerging as an effective technique for providing wireless services to ground users in a variety of scenarios. The efficient deployment of such DSCs while optimizing the covered area is one of the key design challenges. In this paper, considering the low altitude platform (LAP), the downlink coverage performance of DSCs is investigated. The optimal DSC altitude which leads to a maximum ground coverage and minimum required transmit power for a single DSC is derived. Furthermore, the problem of providing a maximum coverage for a certain geographical area using two DSCs is investigated in two scenarios; interference free and full interference between DSCs. The impact of the distance between DSCs on the coverage area is studied and the optimal distance between DSCs resulting in maximum coverage is derived. Numerical results verify our analytical results on the existence of optimal DSCs altitude/separation distance and provide insights on the optimal deployment of DSCs to supplement wireless network coverage.

• The paper analytically derives optimal deployment conditions for drone small cells to maximize coverage and minimize power consumption.
• It employs geometric analysis and LOS probability models to establish optimal altitudes and separation distances in both interference and interference-free scenarios.
• The findings offer actionable strategies for emergency response and enhanced network resilience via adaptable aerial wireless base stations.

Drone Small Cells in the Clouds: Design, Deployment, and Performance Analysis

The paper by Mozaffari et al. seeks to analyze the deployment and performance optimization of drone small cells (DSCs) acting as aerial wireless base stations. The paper focuses on low altitude platform (LAP) systems and investigates the downlink coverage performance, addressing challenges related to coverage optimization, power consumption, and interference management.

Key Contributions and Findings

The primary contribution of the paper is the analytical derivation of optimal conditions for the deployment of single and multiple DSCs to maximize coverage while minimizing power requirements. This is achieved by:

1. Single DSC Optimization: The paper identifies the optimal altitude for a single DSC which balances path loss and line-of-sight (LOS) probability, thereby maximizing ground coverage while minimizing transmit power. Analytical derivations reveal that the optimal altitude leads to maximum coverage when path loss due to distance and shadowing are effectively mitigated.
2. Multiple DSCs Deployment: The paper extends to scenarios involving two DSCs, exploring deployment strategies both with and without interference. In interference-free scenarios, the optimal separation distance is determined by minimizing overlap and ensuring coverage within the specified area. Conversely, in interference-prone situations, the work addresses the complex trade-off between interference levels and optimal DSC separation to maintain maximum effective coverage.
3. Coverage Area and Interference Analysis: The authors employ geometric principles to quantify the coverage area, considering interference-free and fully interfering deployments. The results highlight the existence of a separation distance that needs to be optimized according to interference conditions to achieve maximum coverage in the target area.

Numerical Results and Implications

The numerical results corroborate the analytical findings and provide detailed insights:

• For a given area, a single DSC achieves optimal coverage at a specific altitude which balances LOS probability with path loss, denoting an altitude-dependent power efficiency.
• In situations with two DSCs, the calculated optimal separation distance helps outline deployment strategies that can navigate varying interference conditions, emphasizing the necessity of adapted resource management in aerial networks.

The paper's findings have direct implications for the practical deployment of DSCs in scenarios such as emergency response and enhanced public safety networks. The detailed altitude and deployment analyses provide actionable strategies to expand and optimize the coverage of existing cellular networks efficiently, offering resilience amidst dynamic environmental conditions.

Future Directions

This exploration opens directions for future work focusing on:

• Scalability: Extending the model to deploy multiple DSCs and understanding complex network interactions in urban environments with heterogeneous network demands.
• Dynamic Resource Allocation: Integrating adaptive algorithms that can dynamically modify DSC positions and altitudes based on real-time network and environmental data.
• Advanced Interference Management: Developing sophisticated interference mitigation techniques to optimize spectral efficiency while maintaining robust communication links.

By exploring these dimensions, future research can continue to refine the integration of aerial base stations into broader communication networks, ensuring optimal performance and adaptability to emergent challenges in wireless communications.