The LR-WPAN architecture is defined in terms of a number of blocks in order to simplify the standard. These blocks are called layers. Each layer is responsible for one part of the standard and offers services to the higher layers. The layout of the blocks is similar to the structure of the OSI layered architecture. But the IEEE 802.15.4 standard only defines the PHY and the MAC layers. The upper layers of networking and application have been left for the application developers. An LR-WPAN device comprises a PHY, which contains the radio frequency (RF) transceiver along with its low-level control mechanism, and a MAC sub layer that provides access to the physical channel for all types of transfer. The figure 2.3 depicts the layered architecture of IEEE 802.15.4.
The features of the PHY layer activation and deactivation of the radio transceiver, ED, LQI, channel selection, clear channel assessment (CCA), and transmitting as well as receiving packets across the physical medium. Similarly, the MAC layer is responsible for beacon management, channel access, GTS management, frame validation, acknowledged frame delivery, association, and disassociation.
The features of the PHY layer activation and deactivation of the radio transceiver, ED, LQI, channel selection, clear channel assessment (CCA), and transmitting as well as receiving packets across the physical medium. Similarly, the MAC layer is responsible for beacon management, channel access, GTS management, frame validation, acknowledged frame delivery, association, and disassociation.
