Specifications

Glossary-10
ESS
Extendedserviceset.Alogicalconnectionofmultiplebasicservicesets(BSSs)connectedtothe
samenetwork.RoamingwithinanESSisguaranteedbytheEnterasysNetworksMobilitySystem.
Ethernet II
TheoriginalEthernetspecificationproducedbyDigital,Intel,andXerox(DIX)thatservedasthe
basisoftheIEEE802.3standard.
ETSI
EuropeanTelecommunicationsStandardsInstitute.Anonprofitorganizationthatestablishes
telecommunicationsandradiostandardsforEurope.
European Telecommunications Standards Institute
SeeETSI.
Extended Service Set
SeeESS.
Extensible Authentication Protocol
SeeEAP.
Extensible Markup Language
SeeXML.
failover
Inaredundantsystem,anoperationbywhichastandby(orsecondary)systemcomponent
automaticallytakesoverthefunctionsofanactive(orprimary)systemcomponentwhentheactive
componentfailsoristemporarilyshutdownorremovedforservici ng.Duringandafterfailover,
thesystemcontinuesitsnormaloperationswith
littleornointerru p tioninservice.
FCC
FederalCommunicationsCommission.TheUnitedStates’governingbodyfor
telecommunications,radio,television,cable,andsatellitecommunications.
FDB
Seeforwardingdatabase(FDB).
Federal Communications Commission
SeeFCC.
FHSS
Frequency‐hoppingspread‐spectrum.Oneoftwotypesofspread‐spectrumradiotechnologyused
inwirelessLAN(WLAN)transmissions.TheFHSStechniquemodulatesthedatasignalwitha
narrowbandcarriersignalthat“hops”inapredictablesequencefromfrequencytofrequencyasa
functionoftimeoverawidebandof
frequencies.Interferenceisreduced,becauseanarrowband
interfereraffectsthespread‐spectrumsignalonlyifbotharetransmittingatthesamefrequencyat
thesametime.Thetransmissionfrequenciesaredeterminedbyaspreading(hopping)code.The
receivermustbesettothesamehoppingcodeandmustlisten
totheincomingsignalattheproper
timeandfrequencytoreceivethesignal.CompareDSSS.