A Switched Ethernet Protocol for Hard Real-Time Embedded System Applications

Abstract

This paper presents a protocol to support hard real-time traffic of end-to-end communication over non real-time LAN technology. The network is set up with nodes and switches, and real-time communication is handled by software (protocol) added between the Ethernet protocols and the TCP/IP suite. The proposed protocol establishes a virtual circuit based on admission control and manages hard real-time traffic to bypass the TCP/IP stack. This makes considerably reduce the dwell time in the nodes, and increase the achievable data frame rate. After the bypassing, traffic schedule is performed according to dynamic-priority EDF algorithm. The work does not need any modifications in the Ethernet hardware and coexists with TCP/IP suites, and then the LAN with the protocol can be connected to any existing Ethernet networks. It can be adopted in industrial hard real-time applications such as embedded systems, distributed control systems, parallel signal processing and robotics. We have performed some experiments to evaluate the protocol. Compared to some conventional hard real-time network protocols, the proposed one has better real-time performances and meets the requirements of reliability for hard real-time systems.

Computing Accurate Performance Bounds for Best Effort Networks-on-Chip

“…The interested reader is referred to [12], [13], [14], [15], [16], [17], [18], [19], [20], [21]. Here, we focus on RT-NoCs, which have often been called guaranteed-service or QoS-enabled NoCs.…”

A Novel Hardware-Software Codesign of Network Protocol Stacks on a SoC Platform

“…The HASIS (Hardware Software Interface Synthesis) communication channel supporting message scheduling in reference [13] is based on weighted fair queues for avoiding starvation. Reference [14] proposes a hybrid scheduling scheme based on non-preemptive EDF (Earliest Deadline First) algorithm in order to meet message deadlines and maximize network utilization. We implement and evaluate the scheduling schemes presented by reference [13][14] to compare the performances of providing QoS functionality with our proposed technique.…”

“…Reference [14] proposes a hybrid scheduling scheme based on non-preemptive EDF (Earliest Deadline First) algorithm in order to meet message deadlines and maximize network utilization. We implement and evaluate the scheduling schemes presented by reference [13][14] to compare the performances of providing QoS functionality with our proposed technique. In the research work presented in this paper, we attempt to reconsider these features, which have been reviewed so far in this section at different concepts, and then we succeed in building a SoC platform for real-time embedded network/multimedia systems that can resolve a decomposing problem of implementing any network protocol suite into real-time application-specific and reconfigurable hardware/software tasks.…”

“…4) Decomposed-TCP/IP with RTHC-HASIS is identical with the Decomposed-TCP/IP with RTHC-FIFO except for using the scheduling scheme proposed by [13]. 5) Decomposed-TCP/IP with RTHC-EDF is identical with the Decomposed-TCP/IP with RTHC-FIFO except for using the scheduling scheme proposed by [14]. 6) Decomposed-TCP/IP with RTHC-PIT is identical with the Decomposed-TCP/IP with RTHC-FIFO except for using the scheduling scheme with the PIT module except the DST module.…”