1. Modify the DTIM interval. Good performance has been seen with the DTIM setting of 6.
2. Radio Preambles— radio preamble is a section of data at the head of a packet that contains information that the wireless device and client devices need to send and receive packets. Long Preamble increases interoperability between the WLC and the client. Click on the Wireless tab > Navigate to 802.11 b/g/n > Network option, then uncheck Short Preamble.