Edge Caching in Delay-Constrained Virtualized Cellular Networks: Analysis and Market

Caching of popular contents at cellular base stations, i.e., edge caching, in order to eliminate duplicate transmission through the backhaul can reduce the latency of data delivery in 5G networks. However, since caching can only reduce the backhaul delay, techniques such as base station densification will also need to be used to reduce the fronthaul delay. In this paper, using results from stochastic geometry, we first model the effects of base station densification and cache size on the latency of the system. We then derive a tight approximation for the cache hit probability. To optimize the network cost due to the deployment of base station (BS) and cache storage, a minimization problem for the product of the BS intensity and cache size is formulated under probabilistic delay constraint, which is converted into a geometric program and solved analytically. The results are then used to analyze the economics of a cache-enabled virtualized cellular network where the network infrastructure, i.e., BSs and cache storage, owned by an infrastructure provider (InP) is shared among multiple mobile network operators (MNOs). For the pricing between the InP and the MNOs, we formulate a Stackelberg game with the InP as the leader and multiple MNOs as the followers. In this virtualized scenario, the common cost of renting the infrastructure is shared in a fair manner among the MNOs by using the Shapely value. An efficient algorithm is provided to divide the rent among MNOs. T. Sanguanpuak, N. Rajatheva, and M. Latva-aho are with the Centre for Wireless Communications (CWC), Dept. of Commun. Eng., University of Oulu, Finland (E-mails: {tachporn.sanguanpuak, nandana.rajathava, matti.latva-aho}@oulu.fi). S. Guruacharya and E. Hossain are with the Department of Electrical and Computer Eng., University of Manitoba, Canada (E-mails: {Sudarshan.Guruacharya, Ekram.Hossain}@umanitoba.ca). D. Niyato is with School of Comp. Science and Eng., Nanyang Technological University (E-mail: [email protected]). February 14, 2018 DRAFT