DATA LINK LAYER
The physical layer is responsible for allowing the exchange of bits between two adjacent nodes* of a network. However, these bits are subject to channel impairments, such as noise, interference, or distortion. These channel impairments originate errors in the exchanged bits. As described in Chapter 3, the bit error probability increases with
• The increase of the power of noise, interference, and distortion
• The increase of distance without regeneration
• The decrease of the transmitted power
• The decrease of the reliability of the transmission medium. A radio transmission medium is typically less reliable than an optical fiber. Consequently, the bit error probability of the former transmission medium tends to ...