4. Physical layer

The main role of the physical layer is to establish and maintain the radio or infrared link enabling wireless data transmission between the stations making up the network. To do this, it offers certain primitives to the upper layer. In particular, it provides the MAC layer with primitives enabling it to test the – occupied or available – status of the radio or infrared channel, or to know whether a transmission or reception has just started or ended, etc.

To ensure that the MAC layer is less dependent on the physical layer, a convergence sublayer has been defined to act as an interface between the two. The physical layer is divided into two parts: the PMD and the PLCP sublayer.

The PMD (Physical Medium Dependent) houses all the physical layer functions applied to a given technology.

The convergence sublayer, PLCP...