D-Link DWR-921 User Manual page 73

Section 4 - Connecting to a Wireless Network
5. Enter the same security key or passphrase that is on your router and click
Connect.
It may take 20-30 seconds to connect to the wireless network. If the
connection fails, please verify that the security settings are correct. The key
or passphrase must be exactly the same as on the wireless router.
D-Link DWR-921 User Manual 68