ESTRA: Incentivizing Storage Trading for Edge Caching in Mobile Content Delivery

The explosion of mobile content and usage imposes enormous pressures on mobile communication networks. To reduce content delivery latency and to ease the burden on network bottlenecks (e.g., backhaul networks), besides upgrading the infrastructures, it is promising to cache popular contents at the edge-storage on BSs (Base Stations), APs (Access Points) or other third-party devices associated with BSs and APs, which have been widely deployed in mobile networks. Then it is a challenge here to effectively match such demands of CPs (Content Providers) and the supplies of edge-storage owners because of the complexity caused by the two-fold matching requirements on both coverage and quantity combined with the multi-buyer multi-seller scenario and the divisibility of heterogeneous edge-storages. In this paper, we propose ESTRA (Edge Storage TRading Auction) mechanism to tackle such a challenge. By proposing a region-based model for edge-storage trading, we design a demand cover mechanism to transfer subscriber coverage demands into edge-storage bundle demands and design a truthful, weakly budget balanced and individually rational auction mechanism under the constraints of enabling multi-unit asks and bundle bids. Our theoretical analysis proves the economic robustness, and the simulation result shows that ESTRA achieves 74%-91% of the maximum social welfare and maintains the sustainability of the trading platform through a proper distribution of social welfare.