Efficient coordination of almost blank subframes with coupling macro cells in heterogeneous networks

Abstract

SummaryHeterogeneous networking is an inevitable trend in mobile communication systems, where macrocells and small cells coexist to provide the service of wireless access. The technique of enhanced inter‐cell interference coordination (eICIC) is popularly used to mitigate signal interference among cells. A number of subframes are picked as almost blank subframes (ABSs), during which a macro‐cell base station suspends data transmissions to improve signal quality of small cells that it covers. Since the throughput of macro cells drops to zero in an ABS, how to decide the number of ABSs (ie, the ABS ratio) and their positions (ie, the ABS placement) is critical. Many studies implicitly consider that every small cell resides in only one macro cell and they manage ABSs for each individual macro cell accordingly. In practice, some macro cells may cover the same small cells (called coupling macrocells) which makes the management of their ABSs depend on each other. To address this issue, the paper proposes an efficient coordination of ABS with coupling macro cells (ECO) algorithm. It divides the network into component subnetworks depending on whether macro cells are coupling or not. Then, ECO computes the ABS ratios for the macro cells in each component subnetwork based on multiple factors, including data rate, traffic demand, and quality of service (QoS) support. Moreover, ECO jointly places the ABSs of coupling macro cells to shorten packet latency. Experimental results show that the ECO algorithm not only increases the network throughput but also reduces the loss rate of real‐time data.