Cooperative caching and delivery algorithm based on content access patterns at network edge

Abstract

Mobile network performance and user Quality of Experience have been negatively affected by the explosion of mobile data traffic. This paper proposes mobile edge caching to alleviate the problem. Recent research has focused on local caching at the wireless edge, as motivated by the 80/20 rule regarding content popularity. By caching popular contents at base stations (BSs) closer to users, backhaul congestion and content access latency can be dramatically reduced. To address the limited storage size of BSs in the context of the massive amount of available content, an algorithm optimizing cooperative caching has been highlighted. Contents requested by mobile users that cannot be obtained locally could be transferred by cooperative BSs. In this paper, we propose a cooperative caching algorithm based on BS content access patterns. We use tensor decompositions with distance constraint to analyze interaction between users, contents and base stations. Thus, BSs with small geographical distances and similar content access patterns constitute a cooperative caching domain. The distributed content placement and delivery algorithm is optimized based on simultaneous consideration of the caching hit ratio and cooperative cost. Simulation results based on a real dataset of usage detail records demonstrate the superior performance and promising practical gains in caching of the proposed caching method compared to user clustering and BS clustering.