802. 11g define s the u se of th e same OFDM modulation technique spe cified in IE EE
802. 11a fo r the 5 GHz f requ enc y band an d applie s it in the same 2.4 G Hz f requenc y
band a s IEEE 8 02.11b. The 802.11g stan dard require s ba c kwa rd compatibility with
802. 11b.
The standa rd specifi cally call s fo r:
A. A new phy si cal laye r fo r the 802.11 Medium A cce ss Cont rol (MAC) in the 2. 4 G Hz
f requen cy band, kno wn a s the ex tended rate P HY (E RP ). The E RP add s OFDM a s
a manda to ry ne w coding scheme fo r 6, 12 and 2 4 Mbp s (manda to ry speed s), and
18, 36, 48 and 54 Mbp s (op tional speed s). The E RP in clude s the modulation
sc heme s found in 802.11b including CCK fo r 11 and 5.5 Mbp s a nd Ba rke r code
modulation f or 2 and 1 Mbp s.
B. A pro tec tion mechani sm called RTS/CTS that gove rn s ho w 802.1 1g devi ce s and
802. 11b de vice s inte rope rate.
2. What is the I EEE 802 .11b s tandar d
？
The IE EE 802 .11b Wirele ss LA N standa rd subcommittee , which f ormulate s th e
st anda rd f or the indu st ry . The objec tive i s to enable wi rele ss LA N ha rd wa re f rom
diffe ren t manufa ctu re s to communicate .
3. What does IEEE 8 02.11 fea ture s uppor t
？
The p rodu ct suppo rt s the following I EEE 802 .11 fun ction s:
z
CSMA/ CA plu s A c kno wledge P ro tocol
z
Multi-Channel Roaming
z
Au tomatic Rate Selection
z
RTS /CTS Fea ture
z
Fra gmentation
z
Po we r Management
4. What
is Ad-hoc
？
An Ad -hoc in tegrated wirele ss LA N i s a g roup of compute rs, e ach ha s a Wirele ss LA N
adap ter, Connec ted a s an independ ent wirele ss LA N. Ad hoc wi rele ss LA N i s
applicable a t a depa rtmental scale fo r a b ranch o r SO HO ope ration.
5. What
is Infr astruc ture
？
An integ rated wi rele ss and wirele ss and wired LA N i s called an In f ra st ru ctu re
c onfigu ration. Inf ra stru ctu re i s applicable to ente rp ri se scale fo r wirele ss ac ce ss to
c ent ral databa se, or wi rele ss applica tion fo r mobile worke rs.
6. What is BSS I D
？
A spe cific Ad hoc LAN i s called a Ba si c Se rvice S et (BSS ). Compute rs in a BSS mu st
be configu red with the same BSS I D.
7. What
is WE P
？
WEP i s Wi red Equiv alent P riva cy, a dat a p riva cy me chani sm ba sed on a 40 bit sha red
ke y algo rithm, a s de sc ribed in the IEEE 802 .11 standa rd .
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