SAM: Cache space allocation in collaborative edge-caching network
Edge caching technique is becoming more and more important in 5G network architecture, which shows great performance in terms of mitigating the backbone network congestion and reducing the delivery latency. The key idea of this technique is to cache popular contents in the small base stations(SBSs) which locate at the edge of the wireless network, and deliver these contents to nearby mobile users(MUs) from the cache directly. The collaborative in-cluster prefetching is improving the network performance even more. In this paper, we study the case where one monopolistic state-owned mobile network operator (MNO) offers edge caching service to multiple Content Providers(CPs), and focus on the mechanism design for the cache space allocation in this market. As the caching policy on each edge node is coupled with each other due to in-cluster collaboration, one time auction or flat pricing will both harm the social welfare. We propose a 2-optimal sequential auction mechanism (SAM) to solve this problem, which improves the social welfare by 20%∼70% compared to the traditional Vickery-Clarke-Groves(VCG) mechanism.