STLC2500

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Figure 3. eSCO

6.5.2

V1.2 detailed functionality - Adaptive Frequency Hopping

User Perspective - Adaptive Frequency Hopping

In the Bluetooth spec 1.1, the Bluetooth devices hop in the 2.4 GHz band over 79-channels. As WLAN

802.11 has become popular, there are improvements in the Bluetooth spec 1.2 specifying how Bluetooth

units can avoid jammed bands and provide an improved co-existence with WLAN.

Technical perspective - Adaptive Frequency Hopping

Figure 4. AFH

First the Master and/or the Slaves identify the jammed channels. The Master decides on the channel dis-

tribution and informs the involved slaves. The Master and the Slaves, at a predefined instant, switch to the

new channel distribution scheme.

No longer jammed channels are re-inserted into the channel distribution scheme. AFH uses the same hop

frequency for transmission as for reception.

6.5.3

V1.2 detailed functionality - Faster Connection

User Perspective - Faster Connection

This feature gives the User about 65% faster connection on average when enabled compared to Bluetooth

spec 1.1 connection procedure.

SCO

SCO

SCO

SCO

ACL

ACL

SCO

SCO

eSCO retransmission window

t

t

WLAN used frequency

WLAN used frequency

t

f

f

AFH(79)

AFH(19<N<79)