Please make sure that your WiFi router has a working network connection using other devices. If the network is working properly, please check the following:

1. WiFi frequency: The WS1 can only connect to 2.4GHz (802.11 b/g/n) networks, channels 1-13 (Some older version WS1 devices may only supports channels 1-11). Please note 5GHz WiFi is NOT supported. If you are using a 2.4/5 GHz mixed network, make sure your mobile device is connected to a 2.4 GHz network at the beginning of the setup process. For detailed WiFi setup requirements please check this link.
2. If your WiFi password has changed, you need to go through the WiFi setup again.
3. Battery problems: the WiFi connection consumes a lot of power. Your device may be able to power on but may not have enough power for the WiFi. Try replacing the batteries.
4. Power-saving routers: Your WiFi router may be set to low power or network connection on demand. Some routers do this to save power or to avoid interference. You may need to boost the power of your WiFi router, or move the device closer to the router.
5. Interference: Interference from electrical or electronic devices in the area can cause transmission problems. This may be more prevalent in some industrial settings.
6. WiFi interference. If there are too many other WiFi networks in the vicinity using the same channel, you won't get a good connection. Consider changing to a different channel to avoid interference. Remember, even if the device can't connect to WiFi, it will continue to take measurements and store these internally.