Performance and Implications of RAN Caching in LTE Mobile Networks: A Real Traffic Analysis
Tao Lin, Hongjia Li, Haiyong Xie, Jiasi Chen, Huajun Cui, Guoqiang Zhang, Wei An, Yang Li · 2016
Deploying caches in mobile networks, especially in the radio access network (RAN) is regarded as a promising way to improve mobile user experiences and alleviate the increasing pressure of traffic growth. However, the characteristics of mobile traffic and the performance of RAN caching still remains unclear. In this paper, we extensively analyze the traffic characteristics, the content popularity and the cache performance using a unique dataset collected from a commercial LTE network of China Mobile, from the perspective of mobile access network. The dataset spans nearly a week and consists of a collection of approximately 62.1 millions HTTP sessions, generated by more than 3200 users distributed across three base stations. Based on this realistic dataset, we observe that HTTP traffic can be reduced by 24.4% on average and the hit ratio can reach up to 42.2%, using 100GB cache size. The implications on some fundamental design issues of practical RAN caching systems, including reasonable size of RAN cache, suitable locations of cache deployment and potential benefits of collaborative RAN caching, are further presented. We believe our findings will shed light on practical RAN caching system design.