Abstract
Edge caching-enabled networks can efficiently alleviate data traffic and improve quality of service. However, effectively adapting to users' heterogeneous requests and coordinating among multiple edge servers remains a challenge. In this paper, we address the collaborative cache update and request delivery problem in an edge caching system, aiming to minimize the long-term average system cost under uncertainties of users' heterogeneous demands and dynamic content popularity. To overcome the curse of dimensionality, we decompose the formulated problem into two subproblems: the coordinated proactive cache updating and local request processing. Next, we propose a unified federated deep Q learning (DQL) caching scheme to tackle and coordinate these two subproblems. Particularly, our scheme features a scalable DQL approach with a two-phase action selection procedure to learn the heterogeneous user requests across distributed servers in an online manner. Furthermore, we develop a federated learning (FL)-empowered training process to improve coordination among multiple servers, in which a Thompson sampling (TS)-based algorithm is introduced for smart server selection. We evaluate the performance of our proposed caching scheme in both small-scale and large-scale scenarios through comprehensive experiments, which highlights the advantages of the proposed scheme in terms of caching performance, scalability and robustness.
Original language | English |
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Article number | TMC-2023-06-0636 |
Pages (from-to) | 10855-10866 |
Number of pages | 12 |
Journal | IEEE Transactions on Mobile Computing |
Volume | 23 |
Issue number | 12 |
Early online date | 28 Mar 2024 |
DOIs | |
Publication status | Published - Dec 2024 |
Keywords
- Collaborative edge caching
- deep reinforcement learning (DRL)
- federated learning
- smart server selection