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21 Wireless Local Area Networks
r
max
range of interference between Bluetooth and 802.11 device
(SIR)
min
minimum signal-to-interference ratio
In the second scenario, the MS transmits to the AP and BT-1 receives from
BT-2 (see Figure 21.21), then
r
max
d
[(SIR)
min
(
P
MS
/P
BT
) ]
1/
(21.10)
where:
P
MS
is the transmitted power of the IEEE 802.11 device
If instead of the IEEE 802.11 FH system, the IEEE 802.11 DS system is used
in the scenario of Figure 21.20, the minimum required received SIR at the mobile
terminal is reduced by the processing gain,
G
p
, of the DSSS. The interference
range
r
max
will be:
r
max
d
[(SIR)
min
(
P
BT
/{
P
AP
G
P
}) ]
1/
(21.11)
Similarly, the interference range for the second scenarios of Figure 21.21 with the
IEEE 802.11 DSSS system will be:
r
max
d
[(SIR){
P
MS
/(
P
BT
G
P
}) ]
1/
(21.12)
BT-2
BT-1
802.11 FH
Device
802.11 FH
AP
P
BT
P
MS
d
r
