Thomas Kunz
Systems and Computer Engineering
37
WLAN: IEEE 802.11a
nData rate
–6, 9, 12,
18, 24, 36, 48, 54 Mbit/s, depending
on SNR
–User
throughput (1500 byte packets): 5.3
(6), 18 (24), 24 (36), 32 (54)
–6, 12, 24
Mbit/s mandatory
nTransmission
range
–100m
outdoor, 10m indoor
nE.g., 54 Mbit/s up to 5 m, 48 up to 12 m, 36 up to 25 m, 24 up to 30m, 18 up to 40 m, 12 up to 60 m
nFrequency
–Free
5.15-5.25, 5.25-5.35, 5.725-5.825 GHz
ISM-band
nSecurity
–Limited,
WEP insecure, SSID
nCost
–$280
adapter, $500 base station
nAvailability
–Some
products, some vendors
nConnection set-up time
–Connectionless/always
on
nQuality of Service
–Typ. best effort, no guarantees (same as all 802.11 products)
nManageability
–Limited (no automated key distribution, sym. Encryption)
nSpecial Advantages/Disadvantages
–Advantage: fits into 802.x standards, free ISM-band, available, simple system, uses less crowded 5 GHz band
–Disadvantage: stronger shading due to higher frequency, no QoS