Dynamic Clustering and User Association in Wireless Small-Cell Networks With Social Considerations

In this paper, a novel social network-aware user association in wireless small cell networks with underlaid deviceto-device (D2D) communication is investigated. The proposed approach exploits strategic social relationships between user equipments (TIEs) and their physical proximity to optimize the overall network performance. This problem is formulated as a matching game between TIEs and their serving nodes (SNs) in which, an SN can be a small cell base station (SCBS) or an important UE with D2D capabilities. The problem is cast as a many-to-one matching game in which TIEs and SNs rank one another using preference relations that capture both the wireless aspects (i.e., received signal strength, traffic load, etc.) and users' social ties (e.g., TIE proximity and social distance). Due to the combinatorial nature of the network-wide TIE-SN matching, the problem is decomposed into a dynamic clustering problem in which SCBSs are grouped into disjoint clusters based on mutual interference. Subsequently, an TIE-SN matching game is carried out per cluster. The game under consideration is shown to belong to a class of matching games with externalities arising from interference and peer effects due to users social distance, enabling TIEs and SNs to interact with one another until reaching a stable matching. Simulation results show that the proposed social-aware user association approach yields significant performance gains, reaching up to 26%, 24%, and 31% for 5th, 50th, and 95th percentiles for TIE throughputs, respectively, as compared to the classical social-unaware baseline.

I. Introduction

The proliferation of bandwidth intensive wireless applications such as multimedia streaming and online social networking has led to a tremendous increase in wireless spectral resources [1] . This increasing need for wireless capacity mandates novel cellular architectures for delivering high quality-of-service (QoS) in a cost-effective manner. In this respect, small cell networks (SCNs), built on the premise of deploying inexpensive, low-power small cell base stations (SCBSs) are seen as a key technique to boost wireless capacity and offloading traffic. Reaping the benefits of SCNs requires overcoming a number of challenges that include user association, traffic offloading, resource management, among others [1] –[4]. Along with the rapid proliferation of SCNs, cellular systems are moving from a base station to a user-centric architecture driven by the surge of user specific applications [5]. It is anticipated that a large number of devices with varying QoS requirements will interact within small coverage footprints [6]. Hence, in conjunction with SCNs, device-to-device (D2D) communication over cellular bands has emerged as a promising technique to further improve the performance of SCNs, in which D2D devices communicate directly bypassing the infrastructure yielding increased network capacity, extended coverage, enhanced data offload and improved energy efficiency [6]–[11]. The 3GPP LTE Release 12 has dealt with D2D communication in order to address the ever-increasing demands for data traffic.