Instead, the two technologies may end up being used together: Wi-Fi as the uplink, and FSO for the much faster downlink.
相反，这两类技术最终可能是共同存在：无线连接用于上传，无线光通信用于更高速的下载。
2
Power control consists of forward link (downlink) power control and backward link (uplink) power control.
功率控制分前向链路（下行链路）、反向链路（上行链路）功率控制。
3
The intervention methods are divided into three organizational communication strategies: downlink communication, parallel communication anduplink communication.