A novel approach to scalable CAC for real-time traffic in sink-tree networks with aggregate scheduling

Pedreiras

2014 10th IEEE Workshop on Factory Communication Systems (WFCS 2014)

et al. 2014

In this paper we focus on micro-segmented switchedEthernet networks with HaRTES switches. HaRTES switches provide synchronous and asynchronous real-time traffic scheduling, dynamic Quality-of-Service adaptation and transparent integration of real-time and non-real-time nodes. Herein we investigate the challenges of connecting multiple HaRTES switches in order to build multi-hop communication and we propose a method, named Distributed Global Scheduling, to handle the traffic forwarding in such an architecture while preserving the unique properties of the single HaRTES switch case. Moreover, we develop a response time analysis for the method. We also evaluate the level of pessimism embodied in the analysis. Finally, we show the applicability of the proposed method in an industrial setting by applying it in an automotive case study.

Section: Related Workmentioning

confidence: 99%

Response time analysis of multi-hop HaRTES Ethernet Switch networks

Pedreiras

2014 10th IEEE Workshop on Factory Communication Systems (WFCS 2014)

et al. 2014

“…A class of service curves is introduced to determine the service that is received in an aggregate scheduling network. Furthermore, the work in [22] utilized the mentioned method to investigate an admission control in sink-tree networks.…”

Section: Related Workmentioning

confidence: 99%

“…These messages are generated randomly and all of them are defined as global and of synchronous type to evaluate the method in a multi-hop architecture. The periods of the messages are selected within [2,22]EC and their priorities are assigned based on the Rate Monotonic algorithm within [1,10], where 1 represents the highest priority. Note that, the messages can share a priority level in this example when their periods are equal.…”

Section: A Evaluation Of a Three-switches Networkmentioning

confidence: 99%

Reduced buffering solution for multi-hop HaRTES switched Ethernet networks

2014 IEEE 20th International Conference on Embedded and Real-Time Computing Systems and Applications

Pedreiras

et al. 2014

In the context of switched Ethernet networks, multihop communication is essential as the networks in industrial applications comprise a high amount of nodes, that is far beyond the capability of a single switch. In this paper, we focus on multi-hop communication using HaRTES switches. The HaRTES switch is a modified Ethernet switch that provides real-time traffic scheduling, dynamic Quality-of-Service and temporal isolation between real-time and non-real-time traffic. Herein, we propose a method, called Reduced Buffering Scheme, to conduct the traffic through multiple HaRTES switches in a multi-hop HaRTES architecture. In order to enable the new scheduling method we propose to modify the HaRTES switch structure. Moreover, we develop a response time analysis for the new method. We also compare the proposed method with a method previously proposed, called Distributed Global Scheduling, based on their traffic response times. We show that, the new method forwards all types of traffic including the highest, the medium and the lowest priority, faster than the previous method in most of the cases. Furthermore, we show that the new method performs even better for larger networks compared with the previous one.

“…A class of service curves is introduced to determine the service that is received in an aggregate scheduling network. Furthermore, the work in [17] utilized the mentioned method to investigate an admission control in sink-tree networks.…”

Section: Introductionmentioning

confidence: 99%

Performance analysis of master-slave multi-hop switched ethernet networks

2013 8th IEEE International Symposium on Industrial Embedded Systems (SIES)

Nolte

et al. 2013

There is an increasing trend towards using switched Ethernet in real-time distributed systems due to features like absence of collisions and high throughput. Nevertheless, a few problems persist, in particular related to priority inversion and limited length in queues. In this paper we focus on a protocol which uses a master-slave technique over standard switched Ethernet in order to overcome such problems, namely the FTT-SE protocol. We present an improved response time analysis for such a network and we compare, analytically and with simulations, the results achieved with Network Calculus on a worst-case scenario. We show that our proposed response time analysis gives tighter bounds compared to Network Calculus. Moreover, we compare the performance of different solutions to scale the FTT-SE protocol with respect to the bandwidth utilization. Finally, we propose a new architecture to improve the average performance of master-slave switched Ethernet networks.