DEFINITION - 21

advertisement server: A logical server that provides the information repository for a specific advertisement
protocol. The location of the physical server that instantiates the advertisement server is outside the scope of
this specification.
basic space-time block coding (STBC) modulation and coding scheme (MCS): An MCS value and
STBC encoder specification used in the transmission of STBC-encoded control frames and STBC-encoded
group addressed frames. The value is defined in 9.7.3.
BSSBasicMCSSet: The set of modulation and coding scheme (MCS) values that are supported by all highthroughput
(HT) stations (STAs) that are members of an HT basic service set (BSS).
bufferable management frame: Either an individually addressed Probe Response frame that is sent in an
IBSS in response to an individually addressed Probe Request frame, or an Action, Disassociation, or
Deauthentication frame.
bufferable medium access control (MAC) management protocol data unit (MMPDU): An MMPDU
that is transmitted using one or more bufferable management frames.
bufferable unit (BU): An MSDU, A-MSDU (HT STAs only) or bufferable MMPDU that is buffered to
operate the power saving protocol.
delivery traffic indication message (DTIM) interval: The interval between the consecutive TBTTs of
beacons containing a DTIM. The value, expressed in time units, is equal to the product of the value in the
Beacon Interval field and the value in the DTIM Period subfield in the TIM element in Beacon frames.
direct sequence spread spectrum orthogonal frequency division multiplexing (DSSS-OFDM): A PHY
using DSSS-OFDM modulation under 19.7 rules.
direct sequence spread spectrum/complementary code keying (DSSS/CCK): A Clause 16 or Clause 17
transmission.
dynamic frequency selection (DFS) owner (DO) station (STA): A STA that is the DFS Owner of an IBSS
or off-channel tunneled direct-link setup (TDLS) direct link that is operating on a channel within an
operating class that has a value of 20 or 40 for the entry in the “Channel spacing” column and that has a
value of 5 for the entry in the “Channel starting frequency” column of any of the tables found in E.1.
EAPOL-Key confirmation key (KCK): A key used to integrity-check an EAPOL-Key frame.
EAPOL-Key encryption key (KEK): A key used to encrypt the Key Data field in an EAPOL-Key frame.
emergency services association: A robust security network association (RSNA) between an access point
(AP) and a non-AP station (STA) without security credentials; the non-AP STA is granted access to
emergency services using unprotected frames via this association.
extended channel switching (ECS): A procedure that is used to announce a pending change of operating
channel, operating class, or both.
extended rate PHY (ERP): A PHY conforming to Clause 19
extended rate PHY using CCK modulation (ERP-CCK): A PHY operating under Clause 19 rules.
extended rate PHY using DSSS modulation (ERP-DSSS): A PHY operating under Clause 19 rules.