Traffic-aware association in heterogeneous networks

Abstract

To meet the ever-growing mobile data traffic, network spatial densification with various low-power nodes in addition to the conventional high-power macro base stations (BS), a.k.a. heterogeneous network (HetNet), is regarded as one key enabling solution. Due to the unplanned nature, HetNets are very irregular and severe interference can happen without judicious designs of the user association rules. Conventional maximum downlink (DL) signal-to-interference-plus-noise ratio (SINR) association rule, on the other hand, can not fully release the traffic offloading capabilities of HetNets. Most prior work assumed best-effort (BE) traffic and sought the optimal association to maximize metrics such as the sum of log-rate. In this paper, we model the DL quality-of-service (QoS) flow to each mobile station (MS) explicitly. Aiming to minimize the network-wide packet delay, we investigate the optimal user association scheme and the corresponding resource allocation algorithm. Our proposed traffic-aware user association strategy enjoys low complexity and fast convergence, which is also corroborated with simulations.