STA2416 datasheet(26/38 Pages) STMICROELECTRONICS

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General specification

STA2416

26/38

6.12.1

Algorithm 1: PTA (packet traffic arbitration)

Algorithm 1 is based on a bus connection between the STA2416 and the WLAN chip.

Figure 6.

Algorithm 1: PTA

By using this coexistence interface it's possible to dynamically allocate bandwidth to the two

devices when simultaneous operations are required while the full bandwidth can be

allocated to one of them in case the other one does not require activity. The algorithm

involves a priority mechanism, which allows preserving the quality of certain types of link. A

typical application would be to guarantee optimal quality to the Bluetooth™ voice

communication while an intensive WLAN communication is ongoing.

Several algorithms have been implemented in order to provide a maximum of flexibility and

efficiency for the priority handling. Those algorithms can be activated via specific HCI

commands.

The combination of a time division multiplexing techniques to share the bandwidth in case of

simultaneous operations and of the priority mechanism avoid the interference due to packet

collision and it allows the maximization of the 2.4 GHz ISM bandwidth usage for both

devices while preserving the quality of some critical types of link.

6.12.2

Algorithm 2: WLAN master

In case the STA2416 has to cooperate, in a collocated scenario, with a WLAN chip not

supporting a PTA based algorithm, it's possible to put in place a simpler mechanism.

The interface is reduced to 1 line.

Figure 7.

Algorithm 2: WLAN master

When the WLAN has to operate, it alerts HIGH the RF_NOT_ALLOWED signal and the

STA2416 will not operate while this signals stays HIGH.

This mechanism permits to avoid packet collision in order to make an efficient use of the

bandwidth but cannot provide guaranteed quality over the Bluetooth™ links.

STA2416

D05AU1628

WLAN

STA2416

D05AU1626

WLAN

RF_NOT_ALLOWED

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