Читать книгу Industry 4.0 Vision for the Supply of Energy and Materials - Группа авторов - Страница 32

Wireless networks in industrial environments often rely on solid infrastructures in which large number of devices are randomly spread over a wide deployment area. In addition, communication networks and protocols should be dynamic and support different types of network changes such as device replacement, service modifications, and system upgrades without degrading the desired efficiency and operation. To establish connections and maintain autonomous network connectivity in such environments, wireless systems should be scalable and comply with real-time changes. Scalability is primarily determined by MAC design, and developing scalable MAC protocols is highly challenging [49]. Various techniques are employed in MAC layer that utilize diversity in frequency band, time, and space to deal with scalability. For instance, contention-free conventions such as time-division multiple access (TDMA) protocols are considered to impose strict constraint on network density and fulfill desired quality of service (QoS).