C905
1222-9526 rev. 1
FUNCTIONAL OVERVIEW
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own antenna, on the same device. Because both Bluetooth and WLAN operate in the
same unlicensed ISM band (2.4GHz), steps are required to avoid disturbances and allow
coexistence. The HW solution is a single antenna controlled by an Antenna Switch with
3-wired lines between WLAN Device and BT Device. The used algorithm to decision
whether WLAN device or BT device gets the antenna is Packet Traffic Arbitration (PTA).
WLAN LD configures the PTA during startup of the WLAN device. All PTA parameters are
stored in GDFS. The PTA is configured to prioritize BT traffic if it is a BT high request. All
WLAN traffic should have priority before any BT traffic that is categorized as BT low
requests.
WLAN Driver sends status events to BT Driver to inform about:
• WLAN startup and shutdown
• WLAN association and disassociation
• The current WLAN channel in use
In the cases of WLAN startup and shutdown the BT Logical Driver configures the BT
Device to request the antenna from PTA or not. BT LD also monitors if WLAN have any
connection running. In that case, BT avoids the BT frequencies mapping to the WLAN
channel. WLAN monitors if BT has started any BT Inquiry or page. If this happens any
link loss mechanisms should be temporary turned off for the BT Inquiry or page period.
Bluetooth and WLAN PTA Mechanism:
Bluetooth and WLAN Chip 3-wire Interface:
SEMC Troubleshooting Manual
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