mbehnam.bib

@inproceedings{ASHJAEI_WCTT_2012,
  author = {Ashjaei, M. and Liu, M. and Behnam, M. and Mifdaoui, A. and Almeida, L. and Nolte, T.},
  title = {Worst-Case Delay Analysis of Master-Slave Switched Ethernet Networks},
  booktitle = {2nd International Workshop on Worst-Case Traversal Time (WCTT'2012) Proceedings},
  year = {2012},
  editor = {},
  volume = {},
  series = {},
  pages = {},
  address = {San Juan, Puerto Rico},
  month = {December},
  organization = {},
  publisher = {},
  doi = {},
  issn = {},
  isbn = {},
  keywords = {Ethernet, FTT, FTT-SE, Real-Time communications},
  note = {},
  key = {},
  abstract = {Switched Ethernet is increasingly used in real-time communication due to its intrinsic features such as micro segmentation and high throughput. However, COTS switches may impose long blocking times due to their FIFO queues and can also experience buffer overflow in outgoing queues due to uncontrolled packets arrival. Reconciling the use of ordinary switches with the needs of real-time communication requires an adequate overlay protocol. In this paper we focus on using a Master-Slave technique to overcome the COTS switch limitations in real-time applications, namely the FTT-SE protocol. We extend the protocol for large scale networks and we present the worst-case delay analysis using the Network Calculus formalism for such a network. Moreover, we assess the end-to-end delay of traffic with simulation}
}

@inproceedings{MIFDAOUI_RTN_2012,
  author = {Mifdaoui, A. and Behnam, M. and Nolte, T. and Pedreiras, P. and Almeida, L. and Marau, R.},
  title = {Exploring alternatives to use master/slave full duplex switched Ethernet for avionics embedded applications},
  booktitle = {11th International Workshop on Real-Time Networks (RTN'2012) Proceedings},
  year = {2012},
  editor = {},
  volume = {},
  series = {},
  pages = {},
  address = {Pisa, Italy},
  month = {July},
  organization = {},
  publisher = {},
  doi = {},
  issn = {},
  isbn = {},
  keywords = {Real-Time communications, FTT, Ethernet, Avionics},
  note = {},
  key = {},
  abstract = {The complexity of distributed real-time systems, including military embedded applications, is increasing due to an increasing number of nodes, their functionality and higher amounts of exchanged data. This higher complexity imposes major development challenges when nonfunctional properties must be enforced. On the other hand, the current military communication networks are a generation old and are no longer effective in facing such increasingly complex requirements. A new communication network, based on Full Duplex Switched Ethernet and Master/slave approach, has been proposed previously. However, this initial approach is not efficient in terms of network bandwidth utilization. In this paper we propose two new alternative approaches that can use the network bandwidth more efficiently. In addition we provide a preliminary qualitative assessment of the three approaches concerning different factors such as performance, scalability, complexity and flexibility}
}

@inproceedings{IQBAL_SIES_2012,
  author = {Iqbal, Z. and Almeida, L. and Marau, R. and Behnam, M. and Nolte, T.},
  title = {Implementing hierarchical scheduling on COTS Ethernet switches using a master/slave approach},
  booktitle = {7th IEEE International Symposium on Industrial Embedded Systems (SIES'2012) Proceedings},
  year = {2012},
  editor = {},
  volume = {},
  series = {},
  pages = {76--84},
  address = {Karlsruhe, Germany},
  month = {June},
  organization = {},
  publisher = {},
  doi = {10.1109/SIES.2012.6356572},
  issn = {},
  isbn = {978-1-4673-2683-4},
  keywords = {Real-Time communications, FTT, Ethernet, FTT-SE},
  note = {},
  key = {},
  abstract = {Hierarchical scheduling is instrumental to efficiently deploy component-based designs and achieve composability. It allows partitioning resources into multiple levels, hiding the complexity within each partition behind its respective interface. In this paper we focus on the network resource, particularly on Ethernet using ordinary COTS switches, and we show how hierarchical scheduling can be efficiently deployed using a master/slave approach that enforces the temporal properties of the partitions. We use the FTT-SE protocol for being open source and a bandwidth efficient master/slave alternative currently available for real-time communication over Ethernet. We present a response-time analysis for the traffic submitted within each partition and we validate it using experimental results obtained from a prototype implementation. In particular, the results highlight the strong partitioning capabilities of our approach, with full temporal isolation across partitions in different branches of the hierarchy}
}

@inproceedings{MARAU_WFCS_2012,
  author = {Marau, R. and Behnam, M. and Iqbal, Z. and Silva, P. and Almeida, L. and Portugal, P.},
  title = {Controlling multi-switch networks for prompt reconfiguration},
  booktitle = {9th IEEE International Workshop on Factory Communication Systems (WFCS'2012) Proceedings},
  year = {2012},
  editor = {},
  volume = {},
  series = {},
  pages = {233--242},
  address = {Lemgo, Germany},
  month = {May},
  organization = {},
  publisher = {},
  doi = {10.1109/WFCS.2012.6242571},
  issn = {},
  isbn = {978-1-4673-0693-5},
  keywords = {Real-Time communications, FTT, Ethernet, FTT-SE},
  note = {},
  key = {},
  abstract = {Recent trends in distributed embedded systems, such as those found in avionics and trains, have shown an increase in the amount and heterogeneity of the information that needs to be exchanged, together with a growing importance of supporting dynamic reconfiguration and adaptive behaviors. In this paper we focus on Ethernet technologies with real-time reconfiguration support and we address the case of middle-size networking infrastructures with a few switches. We use the FTT-SE protocol with the needed adaptations to support dynamic heterogeneous real-time transactions in multi-hop networks. The paper presents a worst-case response-time analysis that provides timeliness guarantees, improving the results obtained with another previous analysis, decreasing the needed network capacity for guaranteed schedulability by 25% on average. Practical experiments and simulation results validate the proposed approach and analysis}
}

@inproceedings{ASHJAEI_WFCSWIP_2012,
  author = {Ashjaei, M. and Behnam, M. and Nolte, T. and Almeida, L.},
  title = {Extending FTT-SE protocol for Multi-Master/Multi-Slave Networks},
  booktitle = {9th IEEE International Workshop on Factory Communication Systems (WFCS'2012) WiP Session Proceedings},
  year = {2012},
  editor = {},
  volume = {},
  series = {},
  pages = {},
  address = {Lemgo, Germany},
  month = {May},
  organization = {},
  publisher = {},
  doi = {},
  issn = {},
  isbn = {},
  keywords = {Real-Time communications, FTT, Ethernet, FTT-SE},
  note = {},
  key = {},
  abstract = {}
}

@inproceedings{SANTOS_RTSSATWORK_2011,
  author = {Santos, R. and Pedreiras, P. and Behnam, M. and Nolte, T. and Almeida, L.},
  title = {Demonstrating an Ethernet switch enhanced with hierarchical scheduling},
  booktitle = {32nd IEEE Real-Time Systems Symposium (RTSS'2011) Open Demo Session of Real-Time Techniques and Technologies},
  year = {2011},
  editor = {},
  volume = {},
  series = {},
  pages = {},
  address = {Vienna, Austria},
  month = {November},
  organization = {},
  publisher = {},
  doi = {},
  issn = {},
  isbn = {},
  keywords = {Embedded systems, NES, Ethernet, Switch, FTT, Real-Time communications, Servers, Scheduling, Quality of Service},
  note = {},
  key = {},
  abstract = {The complexity of Networked Embedded Systems (NES) has been growing steeply, due to increases both in size and functionality, and is becoming a major development concern. This situation is pushing for paradigm changes in NES design methodologies towards higher composability and flexibility. Component-oriented design technologies, in particular supported by server-based scheduling, seem to be good candidates to provide the needed properties. As response, we developed a multi-level hierarchical server-based architecture for Ethernet switches that provides composability and supports online adaptation and reconfiguration [1] [2]. This framework exhibits the following features: 1) A hierarchical architecture that supports server composition, virtual real-time channels providing temporal isolation (composability in the time domain); 2) Analytical tools for guaranteed real-time behavior; 3) Simple interface to adapt and reconfigure servers during runtime}
}

@inproceedings{BEHNAM_WCTT_2011,
  author = {Behnam, M. and Iqbal, Z. and Silva, P. and Marau, R. and Almeida, L. and Portugal, P.},
  title = {Engineering and Analyzing Multi-Switch Networks with Single Point of Control},
  booktitle = {1st International Workshop on Worst-case Traversal Time (WCTT'2011) Proceedings},
  year = {2011},
  editor = {},
  volume = {},
  series = {},
  pages = {},
  address = {Vienna, Austria},
  month = {November},
  organization = {},
  publisher = {},
  doi = {},
  issn = {},
  isbn = {},
  keywords = {Real-Time communications, FTT, FTT-SE, Ethernet, Embedded systems},
  note = {},
  key = {},
  abstract = {Recent trends in distributed embedded systems have shown an increase in the amount and heterogeneity of the information that needs to be exchanged, together with a growing importance of supporting dynamic reconfiguration and adaptive behaviors. In this paper we focus on Ethernet technology and we address the case of middle-size networking infrastructure with a few switches. We use the FTT-SE protocol to support dynamic heterogeneous real-time transactions with temporal isolation and we propose the needed scheduling adaptations to support multi-hop network configurations. The paper also includes a companion worst-case response-time analysis that allows verifying the timeliness of the system}
}

@inproceedings{SANTOS_EMSOFT_2011,
  author = {Santos, R. and Behnam, M. and Nolte, T. and Pedreiras, P. and Almeida, L.},
  title = {Multi-level hierarchical scheduling in Ethernet switches},
  booktitle = {11th International Conference on Embedded Software (EMSOFT'2011) Proceedings},
  year = {2011},
  editor = {},
  volume = {},
  series = {},
  pages = {185--194},
  address = {Taipei, Taiwan},
  month = {October},
  organization = {},
  publisher = {},
  doi = {},
  issn = {},
  isbn = {978-1-4503-0714-7},
  keywords = {Embedded Systems, NES, Ethernet, Switch, Analytical models, Bandwidth, Protocols, Real time systems, Servers, Time factors},
  note = {},
  key = {},
  abstract = {The complexity of Networked Embedded Systems (NES) has been growing steeply, due to increases both in size and functionality, and is becoming a major development concern. This situation is pushing for paradigm changes in NES design methodologies towards higher composability and flexibility. Component-oriented design technologies, in particular supported by server-based scheduling, seem to be good candidates to provide the needed properties. As a response we developed a multi-level hierarchical server-based architecture for Ethernet switches that provides composability and supports online adaptation and reconfiguration. This paper extends our work, presenting the associated response-time based schedulability analysis, necessary for the admission control procedure. Additionally, we have derived the temporal complexity of the analysis, which is shown to be O(n2), where n is the number of higher priority components associated with a given server. Finally, we present a proof-of-concept implementation and a set of experimental results that validates the analysis}
}

@inproceedings{BEHNAM_ETFA_2011,
  author = {Behnam, M. and Marau, R. and Pedreiras, P.},
  title = {Analysis and optimization of the MTU in real-time communications over Switched Ethernet},
  booktitle = {16th Conference on Emerging Technologies Factory Automation (ETFA'2011) Proceedings},
  year = {2011},
  editor = {},
  volume = {},
  series = {},
  pages = {1--7},
  address = {Toulouse, France},
  month = {September},
  organization = {},
  publisher = {},
  doi = {10.1109/ETFA.2011.6059021},
  issn = {1946-0740},
  isbn = {978-1-4577-0016-3},
  keywords = {Ethernet, FTT, FTT-SE, protocols, Real-Time communications, Scheduling, MTU},
  note = {},
  key = {},
  abstract = {The Flexible Time-Triggered communication over Switched Ethernet protocol (FTT-SE) was proposed to overcome the limitation of guaranteeing the real-time communication requirements of conventional switches, and at the same time to support reconfiguration of dynamic adaptive systems. The protocol fragments large messages into a sequence of packets that are individually scheduled. The maximum transmission unit (MTU), that restricts the packets size, has a significant effect on the schedulability of the packets. In this paper, we investigate the problem of selecting the optimal MTU size that maximizes the schedulability of real-time messages. We propose two algorithms to find optimal/sub-optimal values of MTU; the first one finds an optimal solution but exhibits high computational complexity, while the second one is sub-optimal but exhibits a lower computational complexity. Finally, we evaluate our proposed algorithms by means of simulation studies and compare their results with the results of assigning MTU to the maximum packet size that the protocol can allow}
}

@inproceedings{YEKEH_SIES_2011,
  author = {Yekeh, F. and Pordel, M. and Almeida, L. and Behnam, M. and Portugal, P.},
  title = {Exploring alternatives to scale FTT-SE to large networks},
  booktitle = {6th IEEE International Symposium on Industrial Embedded Systems (SIES'2011) Proceedings},
  year = {2011},
  editor = {},
  volume = {},
  series = {},
  pages = {},
  address = {Vasteras, Sweden},
  month = {June},
  organization = {},
  publisher = {},
  doi = {10.1109/SIES.2011.5953692},
  issn = {},
  isbn = {978-1-61284-819-8},
  keywords = {Real-Time communications, FTT, FTT-SE, Ethernet, Embedded systems},
  note = {},
  key = {},
  abstract = {Nowadays, most complex embedded systems follow a distributed approach in which a network interconnects potentially large numbers of nodes. One technology that is being increasingly used is switched Ethernet, but real-time variants of this protocol typically limit scalability. In this paper, we focus on the scalability of the Flexible Time Triggered communication over Switched Ethernet (FTT-SE), which has been proposed to support hard real-time applications in a flexible and predictable manner. Moreover, time-triggered and event-triggered communication methods are supported in this protocol. FTT-SE has already been explored and investigated for small scale networked applications. In this paper we address the protocol scalability and suggest three different solutions with a qualitative assessment}
}

@inproceedings{SANTOS_APRES_2011,
  author = {Santos, R. and Pedreiras, P. and Behnam, M. and Nolte, T. and Almeida, L.},
  title = {Demonstrating an Ethernet Switch Enhanced with Hierarchical Scheduling},
  booktitle = {3rd Workshop on Adaptive and Reconfigurable Embedded Systems (APRES'2011) Proceedings},
  year = {2011},
  editor = {},
  volume = {},
  series = {},
  pages = {},
  address = {Chicago, USA},
  month = {April},
  organization = {},
  publisher = {},
  doi = {},
  issn = {},
  isbn = {},
  keywords = {Embedded systems, NES, Ethernet, Switch, FTT, Real-Time communications, Servers, Scheduling, Quality of Service},
  note = {},
  key = {},
  abstract = {The complexity of Networked Embedded Systems (NES) has been growing steeply, due to increases both in size and functionality, and is becoming a major development concern. This situation is pushing for paradigm changes in NES design methodologies towards higher composability and flexibility. Component-oriented design technologies, in particular supported by server-based scheduling, seem to be good candidates to provide the needed properties. As response, we developed a multi-level hierarchical server-based architecture for Ethernet switches that provides composability and supports online adaptation and reconfiguration [1] [2]. This framework exhibits the following features: 1) A hierarchical architecture that supports server composition, virtual real-time channels providing temporal isolation (composability in the time domain); 2) Analytical tools for guaranteed real-time behavior; 3) Simple interface to adapt and reconfigure servers during runtime}
}

@article{SANTOS_SIGBED_2011,
  author = {Santos, R. and Pedreiras, P. and Behnam, M. and Nolte, T. and Almeida, L.},
  title = {Hierarchical server-based traffic scheduling in ethernet switches},
  journal = {ACM SIGBED Review},
  year = {2011},
  volume = {8},
  number = {1},
  pages = {68--69},
  month = {March},
  doi = {},
  issn = {},
  isbn = {},
  keywords = {Ethernet, Real-Time communications, Switch, Servers, Quality of Service},
  note = {},
  key = {},
  abstract = {Distributed Embedded Real-Time Systems (DERTS) are ever more complex, consisting of an increasing number of nodes with more functionality and handling more data. This scenario is pushing for paradigm changes in the methodologies to design complex DERTS. Namely, component-oriented design methodologies, exhibiting the composability property are considered an effective means to tackle the growing complexity of DERTS. Server-oriented architectures have proven to be an effective means to enable controlled resource sharing, providing composability among application components as well as between the application software and the hardware platform on which they execute}
}

@inproceedings{PROCEEDINGS-LABEL,
  author = {Santos, R. and Behnam, M. and Nolte, T. and Almeida, L. and Pedreiras, P.},
  title = {Schedulability Analysis for Multi-level Hierarchical Server Composition in Ethernet Switches},
  booktitle = {9th International Workshop on Real-Time Networks (RTN'2010) Proceedings},
  year = {2010},
  editor = {},
  volume = {},
  series = {},
  pages = {},
  address = {Brussels, Belgium},
  month = {July},
  organization = {},
  publisher = {},
  doi = {},
  issn = {},
  isbn = {},
  keywords = {Ethernet, FTT, FTT-SE, Switch},
  note = {},
  key = {},
  abstract = {The FTT-enabled (Flexible Time-Triggered) Ethernet Switch provides flow-based dynamic scheduling that allows to handle bursty traffic in a bandwidth efficient way. For that, this switch uses adaptive resource-reservation, associating servers to flows or groups of flows. This way, flows have a guaranteed, but bounded, access to the communication resources. These servers can take up a compositional multi-level hierarchy and they can be adapted on-line to make a better use of the available bandwidth. To assure a continued real-time behavior, the FTT-enabled Ethernet Switch integrates an admission control mechanism, which screens all adaptation and/or reconfiguration requests. Whenever such requests may compromise the flow timeliness or exceed the available memory, they are rejected. This paper focuses on the flow timeliness verification, only, providing a response-time based schedulability analysis that permits assessing the schedulability of a hierarchical composition of servers and flows}
}