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Dear Fellow Voting Members of IEEE 802.19, The members of IEEE 802.15 TG4z request that you vote Disapprove on the 802.11ax CAD. Initially, 802.11ax was confined to 2.4 GHz, and 5 GHz bands. However, it has been expanded to include 6-7.125 GHz, and no additional coexistence evaluation has been done to address this change. We are requesting a NO vote because TG4z discussed it at length at our meeting in Warsaw and determined that there is much that needs to be tested and analyzed before coexistence at 6 GHz can be determined. All of this can and should be analyzed. But if we rubber stamp this document that is lacking any evaluation of coexistence with another 802 standard, namely 802.15.4 HRP and LRP UWB PHY’s, then we are proceeding down a perilous path in which coexistence is simply assumed, with no evaluation. This leads to loss of credibility for all 802 wireless standards, especially if there is a coexistence significant problem; which there is. The document calls out for using the same evaluation at 6 GHz as what was used at 5 GHz. There is no UWB standard at 5 GHz. Therefore, a careful evaluation of coexistence is required. It should be noted that 802.11ax allows a maximum output of 17 dBm, while HRP and LRP are limited to -41.3 dBm/MHz. The difference is overwhelming, and in tests performed by DecaWave, it was shown that significant destructive interference is created by an 802.11ax type system when it is in any reasonable proximity to a UWB victim. There may be ways to coexist, and TG4z is open to cooperative discussions to evaluate coexistence methodologies. However, to do that, you must vote Disapprove so that the dialogue can begin. Remember, if you vote Disapprove, you must also provide at least one comment. Shortfalls of the 802.11ax CAD are available for your reference in Mentor at https://mentor.ieee.org/802.15/documents?is_dcn=DCN%2C%20Title%2C%20Author%20or%20Affiliation&is_group=004z, Titled “Comments on 802.11ax CAD”. It is document # 15-18-0239-01-004z-comments-on-802-11ax-cad.pptx. You can also refer to my comments on the 802.19 poll. Best Regards, Tim Harrington To unsubscribe from the STDS-802-19 list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-19&A=1 |