figure. Only and PMD_CBW.ind will be added, as is not in VHT packet. Make changes under heading Figure 22-30 in <this-document> Note – see discussion on comment 5236 before approving. 4109 Adrian 263.11 22.3.21 "Further, through station management (via the PLME) the PHY is set to the appropriate frequency, as specified in 22.4 (VHT PLME)." This is OK as far as it goes. Group membership plays a big part in the MAC-PHY interaction, so it might be good to mention here. Add a sentence to follow cited one: "The PHY has also been configured with group information (i.e., group membership and position in group) so that it can receive data intended for the STA." A Accepted. 5301 Vinko Erceg 263.38 22.3.21 Equation number missing in "defined by RXTIME in Equation ().." As in comment. R Revised. TGac editor: Add an equation number to RXTIME in D2.1 P262L20. Insert that equation number in D2.1 P261L34. 4111 Adrian 263.41 22.3.21 "An invalid L-SIG Length field value is defined as a value not following Equation (35)." This is utterly meaningless. Cited equation determines how to calculate the length given the TXTIME. The receiver is not party to the TXTIME value and cannot therefore validate the L-SIG Length against this value. Alternative suggestions: 1. Add an out-of-band communication of TXTIME so that the receiver can validate it. Possible out-of-band mechanisms include: a) Write it on the back of a post card; b) encode in smoke signals; c) telepathy. 2. Remove cited sentence. 3. Correct sentence to refer to something the receiver can validate. J Rejected. The meaning of the statement is for future-proofing the CCA. As currently defined in D2.1 (Equation 35), Length is modulo 3. Without the sentence an implementer would have been able to treat a packet with Length not modulo 3
Instead the receiver uses the L-SIG length to determin the RXTIME, from which the symbol count is determined. as an invalid 802.11 signal and switch to weaker energy detect for CCA as was done with previous amendments (e.g. invalid Rate in 802.11a). With the cited sentence, a future amendment may use non-modulo 3 Length values and 802.11ac devices will still defer based on Length. The receiver does not need “out-of-band communication of TXTIME”, as it does not need to calculate TXTIME. It merely extracts Length from L-SIG. 4112 Adrian 263.56 22.3.21 "If the received Group ID in VHT-SIG-A has a value indicating an SU PPDU (see 9.17a (Group ID and Partial AID in VHT PPDUs)), the PHY entity may choose not to decode This breaks layering. The PHY should not need to understand any meaning defined in the MAC, unless the MAC tells it. If there was a single fixed "SU" value, then it should be defined in the PHY - but that is not the case. Add to the (22.26) a parameter SU_GROUP_ID", with description: "The SU_GROUP_ID parameter specifies a value that is used by the receiver to determine that a VHT PPDU is an SU PPDU, and that the PPDU is to be received." and modify this description to refer to it: "If the received Group ID in VHT-SIG-A has a value indicating an SU PPDU (i.e., matching the SU_GROUP_ID of the the PHY entity may choose not to decode VHT-SIG-B." J Rejected. The PHY has the Group ID information from VHT-SIG-A. Layering is not broken by referring a person reading a PHY clause to a definition in a MAC clause. 4113 Adrian 264.07 22.3.21 There's no notion in the 22.3.21 description of what to do when we don't care about the received PPDU. Add a statement along these lines: (264.06 may be a suitable location) "The PLCP determines J Revised. Make changes as in <this-doc> under CID 4113 and Figure
to “If the VHT-SIG-A indicates an unsupported mode, the PHY shall set issue PHY_RXSTART.ind (RXVECTOR) then PHY shall issue the error condition 4122 Adrian 267.57 22.3.21 The PMD interface is inadequate to receive an MU PPDU. For the PMD to demodulate a symbol and extract the appropriate user's data requires that it understand which of the STS to demodulate, and which user-specific MCS to expect. However, this information is held in the signal fields, which are comprehended only in the PLCP. 1. Add a new PMD request: with parameters MCS, START_STS, NUM_STS (Add to table 22-62 and new subclauses 22.6.5.x). 2. Update 22.3.21 and figure 22-28 showing generation of this primitive in "Setup PSDU RX". Rejected. Precedence in Clause 18 (802.11a) and Clause 20 (802.11n) is that the PMD has the information from the signal field, e.g. Rate or MCS. No new PMD request is necessary. Discussion: The purpose of an architecture is “divide and conquer” – by dividing a behaviour into smaller pieces with well, documented interfaces, the individual pieces are simpler. The implication of this resolution is that we have two receive state machines: A State machine that is in the PLCP it interfaces between the PMD and MAC-SAP it’s operation is described in text and figures A machine in the PMD It interfaces between the PLCP and the hardware it’s operation is not described anywhere it is of more-or-less equivalent complexity to the PLCP state machine because it is required to detect the different types of signal field in order to decode their contents, which are used to determine how to interpret the rest of the packet. Such an implication is an indictment of our architecture – i.e., it has failed to provide the necessary simplifications.