Distributed Measurement Architecture Research Articles

A distributed measurement architecture for inferring TCP round-trip timesthrough passive measurements

The round-trip time (RTT), defined as the time elapsed for transmission of a data packet to travel from one endpoint to the other and back again, is an important parameter for Internet quality. This paper proposes an extended version of the well-known SYN/ACK (SA) methodology for passively measuring the RTTs over Transmission Control Protocol (TCP) connections. Differently from the original version of the SA methodology and the rest of studies in the related literature, the proposed passive methodology measures not only the total RTT of an end-to-end connection but also the proportion of the existing connection sections on this entire RTT in a passive way if the connection between client and server is established via intermediate stations. A distributed measurement architecture has been designed that implements the extended SA methodology. Through tests in a controlled laboratory environment, various verification and performance evaluation experiments were conducted to determine the accuracy level of the measurement technique and how the distributed architecture behaves regarding resource requirements as the amount of incoming network traffic increases. Accuracy verification experiments show that on average about 92.66 % of the passive measurements are within 10 % or 5 ms, whichever is larger, of the RTT that \textit{ping} would actively measure. Furthermore, the results reveal that using today's commodity hardware, the designed distributed architecture exhibits acceptable satisfactory scaling performance and can practically be used to passively measure RTTs of each hop within medium-sized communication networks.

Privacy Protection Based Secure Data Transaction Protocol for Smart Sensor Meter in Smart Grid

A smart grid is a data communications network integrated with an electrical grid that collects and analyzes near-real-time data on power transmission, distribution, and consumption. Currently, smart grid systems are considered to be necessary for improving the monitoring and control of a power distribution infrastructure. Using distributed measurement architecture, it is possible to gather information about the smart grid status for monitoring and controlling the overall infrastructure, including remote units. This architecture can control the use of electricity. In particular, users can monitor and regulate the electricity consumption of each home appliance in real time. Likewise, power companies can monitor and control electricity consumption for stabilizing electricity supply. However, serious problems can arise in case of data leakage. For example, if malicious attackers can sniff and analyze data, they can obtain the usage pattern of a house and ascertain when it is empty. They could then burgle the house. We propose a privacy-enhanced secure data transaction protocol that can protect private data by encrypting them. The encrypted data include the user's ID, home appliance serial number, and electricity consumption. Thus, attackers cannot obtain important data from the encrypted data. In addition, unauthorized power companies cannot access this information too.

A Novel Power Quality Monitoring Allocation Algorithm

Distributed measurement architecture, due to its efficiency, is used to monitor the power quality in the electric systems. This paper introduces a novel algorithm to determine the optimum allocations of power quality monitors to reduce the cost of the distributed monitoring system taking into account the data redundancy. The optimization problem is formulated as a covering and packing one which can be manipulated by integer linear program algorithms. The appropriate constraints are deduced by the electrical circuit topology independent of the load parameters. In addition, the problem is adopted to a general form which can be implemented by any optimization package. The proposed algorithm is applied to five different systems for validation. Then, the results are discussed in terms of the cost and data redundancy.

A distributed measurement architecture for industrial applications

In this paper, a distributed digital measurement architecture for industrial applications is proposed. The architecture is arranged on three hierarchical communication levels: the fieldbus, the intranet, and the Internet. Particular attention has been paid to the lower level, the field level, implemented using a low-priced smart front-end. It is based on the H8/3048F Hitachi microcontroller and embodies a fieldbus interface (I/F). The same board can be linked to a VXIbus controller by means of a suitable register-based interface. The proposed network can embody a number of analog signal conditioning circuits, processor, and communication capabilities, to meet the industrial needs. We propose two applications of this distributed measurement architecture: the monitoring of power quality in an electrical distribution network and the management of a water distribution system. Experimental results showing the system performance are also included in the paper.

Measuring the internet quality of service in AQUILA

This paper is focussed on design concepts and experiences of the Distributed Measurement Architecture (DMA) used for scalable intra-domain Quality of Service (QoS) monitoring in the framework of the AQUILA DiffServ project. AQUILA DMA consists of QoS measurement tools and methodologies for passive and active QoS monitoring including distributed agents, QoS database, management stations for QoS aggregation and correlation, generation of application traffic classes. The development of such a complex system needs systematic tests to validate the architecture. Therefore application like load generators are used to test the system under different load conditions. For MBAC the admission control agents measure the effective bandwidth consumed by the accepted active IP flows to estimate the unused bandwidth at this access point.