Extended Interframe space (EIFS) is utilized in IEEE 802.11 based WLANs. It tends to be guaranteed that the ACK can be sent by the concerned station without interference from different stations which could not decode the original frame by utilizing the EISF waiting period. EIFS are found in IEEE 802.11. EIFS has a variable value and is utilized when there has been an error in frame transmission. It is not utilized to control access onto the radio connection.