scholarly journals A real-time on-chip network architecture for mixed criticality aerospace systems

2019 ◽  
Vol 123 (1269) ◽  
pp. 1788-1806 ◽  
Author(s):  
S. Majumder ◽  
J.F.D. Nielsen ◽  
A. La Cour-Harbo ◽  
H. Schiøler ◽  
T. Bak
Keyword(s):  
Network Architecture ◽  
Communication Systems ◽  
Contingency Management ◽  
Worst Case ◽  
Temporal Isolation ◽  
Aerospace Systems ◽  
Time Predictability ◽  
On Chip ◽  
Integrated Modular Avionics ◽  
Mixed Criticality

ABSTRACTIntegrated Modular Avionics enables applications of different criticality levels to share the same hardware platform with an established temporal and spatial isolation. On-chip communication systems for such platforms must support different bandwidth and latency requirements of applications while preserving time predictability. In this paper, our concern is a time-predictable on-chip network architecture for targeting applications in mixed-criticality aerospace systems. The proposed architecture introduces a mixed, priority-based and time-division-multiplexed arbitration scheme to accommodate different bandwidth and latency in the same network while preserving worst-case time predictability for end-to-end communication without packet loss. Furthermore, as isolation of erroneous transmission by a faulty application is a key aspect of contingency management, the communication system should support isolation mechanisms to prevent interference. For this reason, a sampling port and isolated sampling buffer-based approach is proposed with a transmission authorisation control mechanism, guaranteeing spatial and temporal isolation between communicating systems.

Effective Multi-Layer Security for Campus Network

2015 ◽  
Vol 2 ◽  
pp. 6
Author(s):  
Isiaka Ajewale Alimi
Keyword(s):  
Network Architecture ◽  
Communication Systems ◽  
Denial Of Service ◽  
High Rate ◽  
Campus Network ◽  
Security Measures ◽  
Security Breaches ◽  
Security Technologies ◽  
Network Layers ◽  
Firewall System

The development in different communication systems as well as multimedia applications and services leads to high rate of Internet usage. However, transmission of information over such networks can be compromised and security breaches such as virus, denial of service, unauthorized access, and theft of proprietary information which may have devastating impact on the system may occur if adequate security measures are not employed. Consequently, building viable, effective, and safe network is one of the main technical challenges of information transmission in campus networks. Furthermore, it has been observed that, network threats and attacks exist from the lower layers of network traffic to the application layer; therefore, this paper proposes an effective multi-layer firewall system for augmenting the functionalities of other network security technologies due to the fact that, irrespective of the type of access control being employed, attacks are still bound to occur. The effectiveness of the proposed network architecture is demonstrated using Cisco Packet Tracer. The simulation results show that, implementation of the proposed topology is viable and offers reasonable degree of security at different network layers.

scholarly journals Design Methodology of Passive In-Line Relays for Molecular Communication in Flow-Induced Microfluidic Channel

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 65
Author(s):  
Puneet Manocha ◽  
Gitanjali Chandwani
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Microfluidic Channel ◽  
Microfluidic Channels ◽  
Molecular Communication ◽  
External Energy ◽  
Lab On Chip ◽  
Molecular Communication Systems ◽  
Macro Scale ◽  
On Chip

Molecular communication is a bioinspired communication that enables macro-scale, micro-scale and nano-scale devices to communicate with each other. The molecular communication system is prone to severe signal attenuation, dispersion and delay, which leads to performance degradation as the distance between two communicating devices increases. To mitigate these challenges, relays are used to establish reliable communication in microfluidic channels. Relay assisted molecular communication systems can also enable interconnection among various entities of the lab-on-chip for sharing information. Various relaying schemes have been proposed for reliable molecular communication systems, most of which lack practical feasibility. Thus, it is essential to design and develop relays that can be practically incorporated into the microfluidic channel. This paper presents a novel design of passive in-line relay for molecular communication system that can be easily embedded in the microfluidic channel and operate without external energy. Results show that geometric modification in the microfluidic channel can act as a relay and restore the degraded signal up-to 28%.

Design of New Dual-Motor Independent Drive System for Electric Vehicle

2012 ◽  
Vol 591-593 ◽  
pp. 251-258
Author(s):  
Wen Wei Wang ◽  
Cheng Lin ◽  
Wan Ke Cao ◽  
Jiao Yang Chen
Keyword(s):  
Electric Vehicle ◽  
Network Architecture ◽  
High Speed ◽  
Simulation Analysis ◽  
Stability Control ◽  
Driving System ◽  
System A ◽  
Important Direction ◽  
Time Predictability ◽  
Information Scheduling

Multi-motor wheel independent driving technology is an important direction of electric vehicle(EV). Based on the analysis of the features of existing independent driving system of electric vehicle, a new dual-motor independent driving system configuration was designed. Complete parameters matching and simulation analysis of the system include motor, reducer, and battery. Distributed control network architecture based on high-speed CAN bus was developed, and information scheduling was optimized and real-time predictability was analyzed based on the rate monotonic (RM) algorithm and jitter margin index. The vehicle lateral stability control was achieved based on coordinated electro-hydraulic active braking. Based on the new dual-motor independent driving system, a new battery electric car was designed and tested. The results show that the vehicle has excellent dynamic and economic performance.

Formal Worst-Case Analysis of Crosstalk Noise in Mesh-Based Optical Networks-on-Chip

2013 ◽  
Vol 21 (10) ◽  
pp. 1823-1836 ◽  
Author(s):  
Yiyuan Xie ◽  
Mahdi Nikdast ◽  
Jiang Xu ◽  
Xiaowen Wu ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Optical Networks ◽  
Case Analysis ◽  
Worst Case Analysis ◽  
Crosstalk Noise ◽  
Worst Case ◽  
Networks On Chip ◽  
On Chip

Reducing Design Margins by Adaptive Compensation for Thermal and Aging Variations

2012 ◽  
pp. 201-230
Author(s):  
Zhenyu Qi ◽  
Yan Zhang ◽  
Mircea Stan
Keyword(s):  
Design Parameters ◽  
Worst Case Analysis ◽  
Transimpedance Amplifier ◽  
Large Area ◽  
Negative Bias Temperature Instability ◽  
Worst Case ◽  
Adaptive Computation ◽  
Bias Temperature Instability ◽  
Computation Efficiency ◽  
On Chip

Corner-based design and verification are based on worst-case analysis, thus introducing over-pessimism and large area and power overhead and leading to unnecessary energy consumption. Typical case-based design and verification maximize energy efficiency through design margins reduction and adaptive computation, thus helping achieve sustainable computing. Dynamically adapting to manufacturing, environmental, and usage variations is the key to shaving unnecessary design margins, which requires on-chip modules that can sense and configure design parameters both globally and locally to maximize computation efficiency, and maintain this efficiency over the lifetime of the system. This chapter presents an adaptive threshold compensation scheme using a transimpedance amplifier and adaptive body biasing to overcome the effects of temperature variation, reliability degradation, and process variation. The effectiveness and versatility of the scheme are demonstrated with two example applications, one as a temperature aware design to maintain IONto IOFFcurrent ratio, the other as a reliability sensor for NBTI (Negative Bias Temperature Instability).

Scheduling Mixed-Criticality Real-Time Tasks in a Fault-Tolerant System

2015 ◽  
Vol 6 (2) ◽  
pp. 65-86 ◽  
Author(s):  
Jian (Denny) Lin ◽  
Albert M. K. Cheng ◽  
Doug Steel ◽  
Michael Yu-Chi Wu ◽  
Nanfei Sun
Keyword(s):  
Real Time ◽  
Fault Tolerant ◽  
Formal Proof ◽  
Worst Case ◽  
Real Time Scheduling ◽  
Important Trend ◽  
Time Scheduling ◽  
On Line ◽  
Computer Tasks ◽  
Mixed Criticality

Enabling computer tasks with different levels of criticality running on a common hardware platform has been an increasingly important trend in the design of real-time and embedded systems. On such systems, a real-time task may exhibit different WCETs (Worst Case Execution Times) in different criticality modes. It is well-known that traditional real-time scheduling methods are not applicable to ensure the timely requirement of the mixed-criticality tasks. In this paper, the authors study a problem of scheduling real-time, mixed-criticality tasks with fault tolerance. An optimal, off-line algorithm is designed to guarantee the most tasks completing successfully when the system runs into the high-criticality mode. A formal proof of the optimality is given. Also, a novel on-line slack-reclaiming algorithm is proposed to recover from computing faults before the tasks' deadline during the run-time. Simulations show that an improvement of about 30% in performance is obtained by using the slack-reclaiming method.

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