A TD-LTE standard-based 4 G bidirectional communication link is designed for outdoor ambient monitoring wireless sensor networks（ WSNs）. A STM32 F103 RCT6 microprocessor unit is employed as the core processor. The air monitoring data that includes wind speed and direction

GPS

carbon dioxide sensor and other sensors are imported by 485 serial port. A flexible extended data communication protocol is defined. The real-time data uploading and autonomous data replenishment mechanism are achieved. Experimental results shows the function of the real-time data uploading and data replenishment as the disconnected network recovered. The effectiveness of communication link is validated.