2.4 GHZ DONGLE BLUETOOTH

In 1-Wire PTA, the Wi-Fi/PTA device asserts a GRANT signal when Wi-Fi is not busy transmitting or receiving. They are 1-Wire PTAпјЊ2-Wire PTAпјЊ3-Wire PTAпјЊ4-Wire PTA.

There are four kinds of PTA implementations as shown in Figure 3.

2.4 GHZ DONGLE BLUETOOTH

For example, if the WLAN radio is operating on channel 1, the Bluetooth radio avoids channels 0-21 or the ZigBee radio avoids channels 11-14. In this approach, the collocated radios avoid the common frequencies for their operation. Every channel is divided into time segments, slots with 11duration 625 Вµsec. During a connection Bluetooth transceivers use all 79 channels and rapidly hop from one channel to another in random manner across all the channels. Frequency hop technique divides the whole frequency spectrum into several hop channels with nominal bandwidth 1 MHz for each channel. Bluetooth is using frequency-hopping spread-spectrum technology (FHSS). However, when implemented by the product designer, a Network Manager function, which can be on the Coordinator or on a Router, can solicit energy scans from the mesh network nodes and initiate a network channel change as necessary to a quieter channel. For Zigbee networks, the Coordinator establishes the initial channel. For Thread networks, frequency separation implementation depends on the application layer. For Wi-Fi networks, the Access Point (AP) establishes the initial channel and, in auto channel configuration, is free to move the network to another channel using the Channel Switch Announcement (CSA), introduced in 802.11h, to schedule the channel change. It is better to use different frequency channels. Co-channel operation of 802.15.4 with 100% duty cycle Wi-Fi blocks most of the 802.15.4 messages and must be avoided.

2.4 ghz dongle