Caching Policies for Delay Minimization in Small Cell Networks With Coordinated Multi-Point Joint Transmissions

• Published in: IEEE/ACM transactions on networking Vol. 29; no. 3; pp. 1105 - 1115
• Main Authors: Ricardo, Guilherme Iecker, Tuholukova, Alina, Neglia, Giovanni, Spyropoulos, Thrasyvoulos
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-06-2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE); IEEE/ACM
• Subjects: Algorithms; Base stations; Caching; CoMP; Computer Aided Engineering; Computer architecture; Computer Science; Delays; distributed algorithms; Edge caching; heterogeneous cellular networks; joint transmission; Minimization; Networks; Optimization; Policies; Quality of service architectures; Resource management; Servers; Signal to noise ratio; Edge caching; joint transmission; optimization; distributed algorithms; heterogeneous cellular networks; CoMP
• ISSN: 1063-6692; 1558-2566
• DOI: 10.1109/TNET.2021.3062269

In 5G and beyond network architectures, operators and content providers base their content distribution strategies on Heterogeneous Networks, where macro and small cells are combined to offer better Quality of Service to wireless users. On top of such networks, edge caching and Coordinated Multi-Point (CoMP) joint transmissions are used to further improve performance. In this paper, we address the average delay minimization problem by first formulating it as a static optimization problem. Even though the problem is NP-hard we are able to solve it via an efficient algorithm that guarantees a <inline-formula> <tex-math notation="LaTeX">\frac {1}{2} </tex-math></inline-formula>-approximation ratio. We then proceed to propose two fully distributed and dynamic caching policies for the same problem. The first one asymptotically converges to the static optimal solution under the Independent Reference Model (IRM). The second one provides better results in practice under real (non-stationary) request processes. Our online policies outperform existing dynamic solutions that are PHY-unaware.