3 Replies Latest reply on Jan 22, 2018 6:18 PM by Intel Corporation

    AC8260 Joule 802.11n SISO early performance threshold


      Poor SISO RF threshold performance was encountered while characterizing the Intel Joule (AC8260 wireless adapter) as a client of an 802.11n Access Point in the 5GHz band.  802.11n Access Point products from two different vendors were tried; these products use differing generations of Qualcomm Atheros chipsets.  Threshold degradation of 8dB was observed during wired hard-line-connected testing.


      Under SISO conditions, for signal levels below an early threshold and above the MIMO threshold, the AC8260 wireless adapter module on the Joule enters a state where it remains connected to the AP, does not search for other AP's, does not disconnect, but also changes to a high MCS level and ceases to transmit.  The situation is exacerbated if the RTS/CTS protocol is enabled.  Then a 20dB early threshold can occur, and in this range of power levels, the Joule will not use the connection but also will not search for a better connection.  Other issues have been observed with RTS/CTS and the Joule.


      Is this behavior a known or understood problem?  What are work-arounds?  Is new firmware anticipated?