Cache-aware user association in backhaul-constrained small cell networks

Abstract

International audienceAnticipating multimedia file requests via caching at the small cell base stations (SBSs) of a cellular network has emerged as a promising technique for optimizing the quality of service (QoS) of wireless user equipments (UEs). However, developing efficient caching strategies must properly account for specific small cell constraints, such as backhaul congestion and limited storage capacity. In this paper, we address the problem of devising a user-cell association, in which the SBSs exploit caching capabilities to overcome the backhaul capacity limitations and enhance the users' QoS. In the proposed approach, the SBSs individually decide on which UEs to service based on both content availability and on the data rates they can deliver, given the interference and backhaul capacity limitations. We formulate the problem as a one-to-many matching game between SBSs and UEs. To solve this game, we propose a distributed algorithm, based on the deferred acceptance scheme, that enables the players (i.e., UEs and SBSs) to self-organize into a stable matching, in a reasonable number of algorithm iterations. Simulation results show that the proposed cell association scheme yields significant gains, reaching up to 21% improvement compared to a traditional cell association techniques with no caching considerations

Fuzzy Q-learning-based user-centric backhaul-aware user cell association scheme

“…We use (18) to calculate these two KPIs. Clearly, our proposed scheme significantly reduces the gap between the target and the achieved throughput for users, who value throughput performance and outperforms Q-learningbased scheme by a margin of 13.87%.…”

“…The concept of intelligent small cells, which exploit Q-learning for dynamic optimization of CREO values in view of the joint radio and backhaul capacity constraints, for maximizing users' quality of experience (QoE) is presented in [17]. A game theoretic-based cache-aware UA algorithm that enables small cells, cognizant of their own caching capabilities and users' mobility patterns, to cache multimedia content in order to enhance users' quality of service (QoS) under backhaul capacity limitations is investigated in [18]. A novel user-centric backhaul-aware UA approach is introduced in [5], that enables users to select a cell that potentially meets their respective QoE requirements.…”

Recent Advances in Cloud Radio Access Networks: System Architectures, Key Techniques, and Open Issues

“…The last challenge is the RRH association strategy. In [136], [137], some base station association strategies that consider the impact of edge cache have been developed for small cell networks. Nevertheless, these strategies are designed for the case where one UE can only be associated with one base station.…”

In-Network Caching and Content Placement in Cooperative Small Cell Networks

“…As the efficiency of caching depends on the ability of each SBS to intelligently select which files to store, i.e., to enhance the hit-ratio of content requests, several works have aimed at maximizing the hit-ratio, by adequately dimensioning the SBSs' caches [4], or based on the mobility estimation of UEs [5]. The file selection and content placement, i.e., the most suitable SBSs in which the files should be cached have been addressed in [3], [6], based on the file popularity distribution.…”