Cache-enabled Knowledge Base Construction Strategy in Semantic Communications
Yue Che, Huachao Xiong, Shujun Han, Xiaodong Xu · 2022 IEEE Globecom Workshops (GC Wkshps) · 2022
With the increasing demand for intelligence in wireless networks, semantic communication is considered as a enabling technology to achieve goal-oriented communication. Deploying semantic knowledge base is seen as a critical technology for support semantic communication in resource-constrained systems. However, the current network architecture does not consider the way of deploying and constructing knowledge bases. To fill this gap, we propose a knowledge base deployment mechanism based on edge caching to support the application of semantic communication. Further, for the semantic understanding-oriented requests of intelligent devices, the knowledge base is considered to be deployed in the edge cache in the form of a knowledge graph. Considering the reusability of triples in requested subgraphs, we define a subgraph value function to measure the translatability and effectiveness of subgraphs, and establish a cached semantic knowledge base value maximization model. Besides, we propose two semantic knowledge base caching strategies, including a subgraph-based dynamic programming caching strategy and a triple-based greedy caching strategy. Compared with other schemes, the recovery accuracy of semantic information and the system delay of the proposed schemes both achieve better performances.