Enhancing Transmission Performance in the LAA and WiFi Heterogeneous Network

The Listen-Before-Talk (LBT) is the main procedure for Licensed Assisted Access (LAA) to accomplish fair and friendly coexistence with other operators or technologies operating over unlicensed spectrum. However, in LBT, the lack of coordination with the other existing systems brings challenges in sustaining performance in the coexistence of LAA and WiFi networks. Specifically, the hidden node situation (HNS) and exposed node situation (ENS) cannot be effectively handled when both LAA and WiFi attempt to access the unlicensed spectrum at the same time. Thus, transmission failure might occur and the network performance would be degraded. In order to mitigate the influences caused by HNS and ENS, based on LBT, a Give-And-Take (GAT) mechanism with the Listen Before-Receive (LBR) procedure is proposed in this paper. With GAT, the LAA sender conditionally gives up or takes back transmission opportunities, and thus the unlicensed spectrum could be efficiently shared between LAA and WiFi in terms of energy usage and throughput. Evaluation results show that the proposed GAT could conditionally obtain better network performance comparing to legacy LBT.