W Hy C Ross - Layer ? I Ts Advantages and Disadvantages

Growing interest and penetration of wireless networking technologies is underlining new challenges in the design and optimization of communication protocols. Traditionally, protocol architectures follow strict layering principles, which ensure interoperability, fast deployment, and efficient implementations. However, lack of coordination between layers limits the performance of such architectures due to the specific challenges posed by wireless nature of the transmission links. To overcome such limitations, cross-layer design has been proposed. Its core idea is to maintain the functionalities associated to the original layers but to allow coordination, interaction and joint optimization of protocols crossing different layers. This chapter introduces the reader with the notion of the cross-layer design, outlining motivations and requirements, presents the main building blocks enabling collaboration between layers, and compares available signaling architectures. Then, after mentioning current status of standardization activities in the field, it presents novel architectural solutions involving cross-layer design which are proposed in the framework of next generation network communications.