In layer based approaches researchers concentrate on Network and MAC layers
If the signal is weak enough and the node moving away, the MAC layer sends a Request To Send (RTS).
After several unsuccessful attempts, the MAC layer informs to the routing layer that communication failed, using the variable xmit_reason with the value XMIT_REASON_RTS or XMIT_REASON_ACK (see Algorithm1).
The IEEE P1901 standard defines several packet types which can be interchanged between stations at the MAC layer (Fig.
Simulator design incorporates both MAC layer protocols and PHY layer characteristics.
11 based MAC protocols, virtual carrier sensing is used at the MAC layer to determine the availability of the wireless medium.
The control frames include the transmission of route request, route response packets at the network layer as well as the RTS/CTS/ACK packets at the MAC layer.
4 standards, advanced MAC protocols for ZigBee networks, energy optimization techniques of the PHY and MAC layers
, security issues, coexistence issues between ZigBee and other networks, ZigBee profile, developing ZigBee certified products, monitoring the efficiency of workflow, and ZigBee versus other protocols and standards.