PHYs!)
http://standards.ieee.org/getieee802/download/802.11-1999.pdf
and yes, its required.... even in 'Ad Hoc' (IBSS) mode.
9.2.5.7 CTS procedureI don't know what you mean by 'RTS/CTS option', perhaps you mean the RTS threshold. This is part of the MAC MIB.
A STA that is addressed by an RTS frame shall transmit a CTS frame after a SIFS period if the NAV at the
STA receiving the RTS frame indicates that the medium is idle. If the NAV at the STA receiving the RTS
indicates the medium is not idle, that STA shall not respond to the RTS frame. The RA field of the CTS
frame shall be the value obtained from the TA field of the RTS frame to which this CTS frame is a response.
The Duration/ID field in the CTS frame shall be the duration field from the received RTS frame, adjusted by
subtraction of aSIFSTime and the number of microseconds required to transmit a CTS frame at the data rate
used for the RTS frame to which this CTS frame is a response.
After transmitting an RTS frame, the STA shall wait for a CTSTimeout interval, starting at the PHYTXEND.
confirm. If a PHY-RXSTART.indication does not occur during the CTSTimeout interval, the STA
shall conclude that the transmission of the RTS has failed, and this STA shall invoke its backoff procedure
upon expiration of the CTSTimeout interval. If a PHY-RXSTART.indication does occur during the
CTSTimeout interval, the STA shall wait for the corresponding PHY-RXEND.indication to determine
whether the RTS transmission was successful. The recognition of a valid CTS frame sent by the recipient of
the RTS frame, corresponding to this PHY-RXEND.indication, shall be interpreted as successful response,
permitting the frame sequence to continue (see 9.7). The recognition of anything else, including any other
valid frame, shall be interpreted as failure of the RTS transmission. In this instance, the STA shall invoke its
backoff procedure at the PHY-RXEND.indication and may process the received frame.
9.2.6 Directed MPDU transfer procedure
A STA shall use an RTS/CTS exchange for directed frames only when the length of the MPDU is greater
than the length threshold indicated by the dot11RTSThreshold attribute.
The dot11RTSThreshold attribute shall be a managed object within the MAC MIB, and its value may be set
and retrieved by the MAC LME. The value 0 shall be used to indicate that all MPDUs shall be delivered with
the use of RTS/CTS. Values of dot11RTSThreshold larger than the maximum MSDU length shall indicate
that all MPDUs shall be delivered without RTS/CTS exchanges.
When an RTS/CTS exchange is used, the asynchronous data frame shall be transmitted after the end of the
CTS frame and a SIFS period. No regard shall be given to the busy or idle status of the medium when transmitting
this data frame.
Jim On Thursday, October 17, 2002, at 02:07 AM, Alexis wrote:
Could it be part of 802.11a data rates to limit RTS thresholds so to force a certain speed at certain receive sensitivities. alexisHi all, Does anyone know if the RTS/CTS option is required for 802.11a devices in Ad Hoc mode? I am asking because all of the 802.11a PCMCIA cards on the market right now (Intel, SMC, Linksys) does not seem to have the RTS/CTS option on the client side driver. --Gavin __________________________________________________ Do you Yahoo!? Faith Hill - Exclusive Performances, Videos & More http://faith.yahoo.com -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless-- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
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