In recent years, various internet architectures, such as Integrated Services (IntServ), Differentiated Services (DiffServ), Time Sensitive Networking (TSN) and Deterministic Networking (DetNet), have been proposed to meet the quality-of-service (QoS) requirements of different network services. Concurrently, network calculus has found widespread application in network modeling and QoS analysis. Network calculus abstracts the details of how nodes or networks process data packets using the concept of service curves. This paper summarizes the service curves for typical scheduling algorithms, including Strict Priority (SP), Round Robin (RR), Cycling Queuing and Forwarding (CQF), Time Aware Shaper (TAS), Credit Based Shaper (CBS), and Asynchronous Traffic Shaper (ATS). It introduces the theory of network calculus and then provides an overview of various scheduling algorithms and their associated service curves. The delay bound analysis for different scheduling algorithms in specific scenarios is also conducted for more insights.

Time-sensitive networking (TSN) is an important research area for updating the infrastructure of industrial Internet of Things. As a product of the integration of the operation technology (OT) and the information technology (IT), it meets the real-time and deterministic nature of industrial control and is compatible with Ethernet to support the mixed transmission of industrial control data and Ethernet data. This paper systematically summarizes and analyzes the shortcomings of the current mixed transmission technologies of the bursty flows and the periodic flows. To conquer these shortages, we propose a predictive mixed-transmission scheme of the bursty flows and the periodic flows. The core idea is to use the predictability of time-triggered transmission of TSN to further reduce bandwidth loss of the previous mixed-transmission methods. This paper formalizes the probabilistic model of the predictive mixed transmission mechanism and proves that the proposed mechanism can effectively reduce the loss of bandwidth. Finally, based on the formalized probabilistic model, we simulate the bandwidth loss of the proposed mechanism. The results demonstrate that compared with the previous mixed-transmission method, the bandwidth loss of the proposed mechanism achieves a 79.48% reduction on average.

The Metro Ethernet Forum (MEF ) put forward the concept of Carrier Ethernet (CE ) to improve Ethernet technology and make it a transmission convergence layer solution for Next Generation Network (NGN ). Provider Backbone Transport (PBT ) is the result of the enhancement and improvement of the early Ethernet technologies and it is the new version of CE implementation technology and standard which is promising. Through studying the PBT- related technologies, PBT network structure, PBT advantages as the transmission convergence layer solution and its trend of future development, it is concluded that PBT can be used as the preferred technology of the transmission convergence layer in the NGN, though there are some problems to be solved for PBT.