The present invention concerns a method and a device for transmitting sensor data in a wireless network. The network is based on a shared transmission channel. Access to the shared transmission channel is scheduled by the master node. The slave node comprises an acquisition device producing said data. The method comprises on the slave node: obtaining a request for acquiring data from the master node; estimating the value of a time information representative of a delay for the acquisition device to acquire a block of data ready for transmission; sending a message to the master node comprising the estimated time information; receiving an authorization of transmission from the master node, said authorization of transmission being scheduled at a time depending on the estimated time information; and transmitting a block of data to the master node after said reception according to the received authorization. Accordingly, the communication channel is reserved at the right time allowing minimizing the bandwidth and the latency.