Stochastic Content-Centric Multicast Scheduling for Cache-Enabled Heterogeneous Cellular Networks

Abstract

Abstract-Caching at small base stations (SBSs) has demonstrated significant benefits in alleviating the backhaul requirement in heterogeneous cellular networks (HetNets). While many existing works focus on what contents to cache at each SBS, an equally important problem is what contents to deliver so as to satisfy dynamic user demands given the cache status. In this paper, we study optimal content delivery in cache-enabled HetNets by taking into account the inherent multicast capability of wireless medium. We consider stochastic content multicast scheduling to jointly minimize the average network delay and power costs under a multiple access constraint. We establish a content-centric request queue model and formulate this stochastic optimization problem as an infinite horizon average cost Markov decision process (MDP). By using relative value iteration and special properties of the request queue dynamics, we characterize some properties of the value function of the MDP. Based on these properties, we show that the optimal multicast scheduling policy is of threshold type. Then, we propose a structure-aware optimal algorithm to obtain the optimal policy. We also propose a lowcomplexity suboptimal policy, which possesses similar structural properties to the optimal policy, and develop a low-complexity algorithm to obtain this policy.

Reliability-Centric Analysis of Offloaded Computation in Cooperative Wearable Applications

“…In the Long Term Evolution (LTE) cellular networks by 3GPP, two types of locations appear attractive for deploying 5G-grade caches [49]: (i) in the Evolved Packet Core (reflecting the cloud computing paradigm) or (ii) in the RAN on the base station side (representing the MEC concept). For example, caching the content library at the femtocell stations (so-called femtocaching [50]) holds a promise to mitigate the backhaul requirements in next-generation 5G-grade HetNets [51].…”

Energy-Efficient Joint Design of Fronthaul and Edge Links for Cache-Aided C-RAN Systems with Wireless Fronthaul

“…The overhead, or capacity requirements, of the fronthaul links in C-RAN systems can be alleviated by adopting narrowband IoT (NB-IoT) technology, which supports low-power and low-cost devices [20], or by adding edge caching functionalities to RRHs [21][22][23][24][25][26][27][28]. The idea of the latter is that the RRHs are equipped with local caches at which popular content frequently requested by mobile user equipment (UE) are pre-fetched, such that the amount of data delivered over the fronthaul links can be reduced at the delivery phase.…”

“…In [27], an information theoretic analysis of cache-aided C-RAN systems was addressed. In [21][22][23][24][25][26]28] cache-aided C-RAN systems were studied in the aspects of signal processing. Specifically, signal processing optimization for the delivery phase for fixed pre-fetching strategies was discussed in [23][24][25][26]28].…”

Content-oriented network slicing optimization based on cache-enabled hybrid radio access network

“…Issues on network slicing optimization integrated with content networks are discussed in [34][35][36]. A Content Delivery Network as a Service (CDNaaS) platform is presented in [34] which focused on optimal placement of virtual machine and flavor selection for different images aiming at minimizing the cost of CDN slice owner and maximizing the quality of experience of streaming.…”

“…A Content Delivery Network as a Service (CDNaaS) platform is presented in [34] which focused on optimal placement of virtual machine and flavor selection for different images aiming at minimizing the cost of CDN slice owner and maximizing the quality of experience of streaming. In [35], the optimal content delivery strategy in cache-enabled HetNet is proposed by formulating a stochastic multicast scheduling problem to jointly minimize the average network delay and power costs taking into account the inherent multicast capability of wireless medium. In [36], a centrality-based caching algorithm is proposed in ICN based on complex network by exploiting the concept of (ego network) betweenness centrality to improve the caching gain and eliminate the uncertainty in the performance of the simplistic random caching strategy.…”