Protocol Emulation Research Articles

Novel Framework-Based Routing for Task-Adaptive Mobile Networks of Unmanned Aerial Vehicular

Many practical mobile ad hoc networks (MANET) have certain tasks instead of just randomly changing each node’s positions. We call such a mission-driven network task-adaptive MANET. A typical example is the flying ad hoc network (FANET) that consist of unmanned aerial vehicles (UAVs), which may change its network topology based on different task requirements. Each node moves to new locations based on the targeted network shape. To maintain a smooth topology transformation and minimize the position changes, during shape change, a MANET typically keeps the core-area nodes more stable and allows the nodes in the outer area of the network to move more drastically. This means the entire network has an approximate framework that reflects the relatively stable nodes located in the core area. This research proposes a new routing scheme to quickly identify the optimal end-to-end path using the network framework extraction result. The proposed routing scheme ensures that the packets flow along the more stable network regions (thus with a lower packet loss rate). The framework extraction scheme is based on network shape geometry analysis for the median axis recognition. Our work has contributions to three aspects of realistic network protocol applications: (1) Provides a network multi-center election and member control methodology with detailed protocol design. (2) Creates a stable and reliable MANET framework extraction algorithm which aids in routing table generation. (3) Real-time Unix system protocol implementation and emulation based on Common Open Research Emulator (CORE) + Extendable Mobile Ad-hoc Network Emulator (EMANE). Simulation results indicate that our framework-based routing scheme outperforms a popularly used mobility-adaptive MANET routing scheme—OLSR (optimized link state routing)—in terms of throughput and delay.

A Survey on Emulation of Communication Protocols in Microcontrollers

Basic emulation of communication protocols involves the emulation or replicating the frames of the communication protocols using the port pins. This is useful when there is a particular need for a protocol inside a microcontroller where the required communication protocol is not present. The survey on emulation is suitable for the users to have a brief knowledge about the emulation before proceeding. This survey on emulation of communication protocols gives a brief information regarding the parameters, timing, and also the issues and problems faced during the emulation. A brief comparison was made with some different communication protocol emulation using a simple timer module. This will be helpful in concluding the behavior of each communication protocol on a simple timer module using which the protocol will be emulated.

A Framework for Analyzing and Testing Cyber–Physical Interactions for Smart Grid Applications

The reliable performance of the smart grid is a function of the configuration and cyber–physical nature of its constituting sub-systems. Therefore, the ability to capture the interactions between its cyber and physical domains is necessary to understand the effect that each one has on the other. As such, the work in this paper presents a co-simulation platform that formalizes the understanding of cyber information flow and the dynamic behavior of physical systems, and captures the interactions between them in smart grid applications. Power system simulation software packages, embedded microcontrollers, and a real communication infrastructure are combined together to provide a cohesive smart grid cyber–physical platform. A data-centric communication scheme, with automatic network discovery, was selected to provide an interoperability layer between multi-vendor devices and software packages, and to bridge different protocols. The effectiveness of the proposed framework was verified in three case studies: (1) hierarchical control of electric vehicles charging in microgrids, (2) International Electrotechnical Committee (IEC) 61850 protocol emulation for protection of active distribution networks, and (3) resiliency enhancement against fake data injection attacks. The results showed that the co-simulation platform provided a high-fidelity design, analysis, and testing environment for cyber information flow and their effect on the physical operation of the smart grid, as they were experimentally verified, down to the packet, over a real communication network.

Protocol-Independent Event Building Evaluator for the LHCb DAQ System

The Data Acquisition (DAQ) system of LHCb is a complex real-time system. It will be upgraded to provide LHCb with an all-software, trigger-free readout starting from 2020. Consequently, more CPU power in the form of servers will be needed and the DAQ network will grow to a capacity of 40 Tbps. A PC-based readout system would receive data incoming from the detector, which would then be scattered across builder nodes, and further distributed to a computing farm for data filtering. The design bandwidth of such a DAQ system requires rates as high as 400 Gbps single-duplex per node. These builder nodes will be connected with cost-effective, high-bandwidth data-centre switches in order to minimize the system cost. The behaviour of such an Event Building network can of course be studied in simulation but experience tells us that it is crucial to test, in particular to find out limitations in the switches themselves and to which extent various Event Building protocols can mitigate these limitations. We present a protocol, topology and transport independent emulation software named DAQ Protocol-Independent Performance Evaluator (DAQPIPE). It allows us to test different communication architectures, such as push or pull, with regards to the initiator of the communication. Different topologies and transport protocols can also be tested. We present throughput and stress tests on an InfiniBand FDR multi-rail based LAN network setup, with a focus on the network performance. Large tests on the current system LHCb DAQ are shown to demonstrate the scalability of DAQPIPE itself and its capability to be deployed on any kind of large, tightly interconnected network to test its suitability for Event Building applications.

An Experimental Study of Selective Cooperative Relaying in Industrial Wireless Sensor Networks

Strict reliability and delay requirements of factory monitoring and control applications pose challenges for wireless communications in dynamic and cluttered industrial environments. To reduce outage in such fading-rich areas, cooperative relays can be used to overhear source-destination transmissions and forward data packets that a source fails to deliver. This paper presents the results of an experimental study of selective cooperative relaying protocols that are implemented in off-the-shelf IEEE 802.15.4-compatible devices and evaluated in an industrial production plant. Three practical relay update schemes, which define when a new relay selection is triggered, are investigated: 1) periodic; 2) adaptive; and 3) reactive relay selections. The results show that all relaying protocols outperform conventional time diversity retransmissions in delivery ratio and number of retransmissions for packet delivery. Reactive selection provides the best overall delivery ratio of nearly 99% over the tested network. There is a tradeoff, however, between achievable delivery ratio and required selection overhead. This tradeoff depends on protocol and network parameters, and is studied via protocol emulation using empirical channel values.

실시간 운영체제의 우선순위 역전현상 해결을 위한 프로토콜 설계 및 구현

실시간 운영체제는 정해진 시간 내에 작업처리를 완료해야 하는 분야에 주로 사용되고 있으며, 최적의 실시간 운영체제를 설계하고 개발하기 위해서는 효과적인 스케줄링 정책, 인터럽트 지연 최소화, 우선순위 역전현상 해결 등의 조건을 만족시켜야한다. 이러한 조건들 중에서 우선순위 역전현상을 해결하기 위해 지금까지 basic priority inheritance 프로토콜, priority ceiling emulation 프로토콜 등이 제안되었으나, 하나의 프로세스가 동시에 다수의 자원을 소유하는 경우 또는 재귀적으로 자원을 소유하거나 요청하는 경우와 같이 대표적인 두 가지 복잡한 우선순위 역전현상에 대해서는 해결이 불가능하다. 이에 본 논문에서는 재귀적 자료구조를 기반으로 다양한 우선순위 역전현상을 효과적으로 해결할 수 있는 RPI(Recursive Priority Inheritance) 프로토콜을 설계하고, 이를 리눅스 커널에 구현하여 검증한 내용을 보인다. Real-time operating systems have been used in various computing environments, where a job must be completed in its deadline, with various conditions, such as effective scheduling policies, the minimum of an interrupt delay, and the solutions of priority inversion problems, that should be perfectly satisfied to design and develop optimal real-time operating systems. Up to now, in order to solve priority inversion problems among several those conditions. There have been two representative protocols: basic priority inheritance protocol and priority ceiling emulation protocol. However, these protocols cannot solve complicated priority inversion problems. In this paper, we design a protocol, called recursive priority inheritance (RPI), protocol that effectively solves the complicated priority inversion problems. Our proposed protocol is also implemented in the Linux kernel and is compared with other existing protocols in the aspect of qualitative analysis.

PROTEAN: a high-level Petri net tool for the specification and verification of communication protocols

The PROTEAN protocol emulation and analysis computer aid is presented. It is based on a formal specification technique called numerical Petri nets (NPNs), and provides both graphical (color) and textual interfaces to the protocol designer. NPN specifications may be created, stored, appended to other NPNs, structured, edited, listed, displayed, and analyzed. Interactive simulation, exhaustive reachability analysis, and several directed graph analysis facilities are described. Specification languages are compared, with concentration on extended finite state machines and high-level Petri nets. Both the NPN and PROTEAN facilities are described and illustrated with a simple example. The application of PROTEAN to complex examples is mentioned briefly. Work towards a comprehensive protocol engineering workstation is also discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>