Hello @Sharmane 

Thank you for reaching out to us and welcome to the TP-Link community.

After you configure the WR940N to connect to the HUAWEI B818 wirelessly, how about the WDS status on the WR940 status page? Please review the configuration guide again and ensure all the wireless settings match the settings on the HUAWEI B818: 

How to configure WDS function on TP-Link Wireless Routers

If the WR940N still doesn't have internet, please check if there are any Whitelist settings on your Huawei B818 and be sure the WR940N is on the list. 

Most importantly, when building a WDS you should bare in mind that:

"In order to build a successful WDS connection between different devices, it requires that both devices use the same wireless MAC address format. For example, Site A uses 4-address MAC Address format in passive WDS bridge mode, Site B also uses 4-address MAC Address format in active WDS bridge mode.

WDS may be incompatible between different products (even occasionally from the same vendor) since the IEEE 802.11-1999 standard does not define how to construct any such implementations or how stations interact to arrange for exchanging frames of this format.-----From Wikipedia"