Adaptive configuration of time-domain eICIC to support multimedia communications in LTE-A heterogeneous networks

摘要

Long term evolution-advanced (LTE-A) supports high-speed communications for cellular systems. It allows different types of base stations to form a heterogeneous network to provide service. However, signal interference between a macrocell and its picocells is inevitable. Thus, LTE-A adopts enhanced intercell interference coordination (eICIC) to conquer the interference problem. In the time-domain eICIC strategy, a number of subframes are selected as almost blank subframes (.ABSs) during which data transmission of the macrocell is suspend, so as to improve the utilization of spectral resource in picocells. How to configure the number of ABSs in each period, namely the ABS ratio, has significant impact on system performance. Most of existing studies aim to decide the ABS ratio to increase network throughput according to channel condition or traffic demands of user devices. However, none of them considers delay requirement of multimedia flows. Consequently, the paper proposes an adaptive configuration mechanism to dynamically change the ABS ratio to support quality of service (QoS) for multimedia communications by measuring the transmission capacity of each cell and the amount of urgent multimedia data. Through LTE-Sim experiments, we demonstrate that the proposed configuration mechanism can efficiently improve throughput of macrocells and picocells, while reducing video packet dropping due to expiration.