Smart grids heavily depend on communication in order to coordinate the generation, distribution, and consumption of energy-even more so if distributed power plants based on renewable energies are taken into account. Given the variety of communication partners, a heterogeneous network infrastructure consisting of IP-based and suitable field-level networks is the most appropriate solution. This paper investigates such a two-tier infrastructure and possible field-level networks with particular attention to metering and supervisory control and data acquisition applications. For the problem of network integration, a combination of gateway and tunneling solutions is proposed which allows a semitransparent end-to-end connection between application servers and field nodes. The feasibility of the approach and implementation details are discussed at the example of powerline communication and IP-based networks investigated in the European research project on real-time energy management via powerlines and internet. Nevertheless, it is shown that the communication architecture is versatile enough to serve as a generic solution for smart grids.

End-to-End Communication Architecture for Smart Grids

Survey A survey of routing protocols for smart grid communications

In recent years, industrial wireless sensor networks (IWSNs) have emerged as an important research theme with applications spanning a wide range of industries including automation, monitoring, process control, feedback systems, and automotive. Wide scope of IWSNs applications ranging from small production units, large oil and gas industries to nuclear fission control, enables a fast-paced research in this field. Though IWSNs offer advantages of low cost, flexibility, scalability, self-healing, easy deployment, and reformation, yet they pose certain limitations on available potential and introduce challenges on multiple fronts due to their susceptibility to highly complex and uncertain industrial environments. In this paper, a detailed discussion on design objectives, challenges, and solutions, for IWSNs, are presented. A careful evaluation of industrial systems, deadlines, and possible hazards in industrial atmosphere are discussed. This paper also presents a thorough review of the existing standards and industrial protocols and gives a critical evaluation of potential of these standards and protocols along with a detailed discussion on available hardware platforms, specific industrial energy harvesting techniques and their capabilities. This paper lists main service providers for IWSNs solutions and gives insight of future trends and research gaps in the field of IWSNs.

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A Critical Analysis of Research Potential, Challenges, and Future Directives in Industrial Wireless Sensor Networks

This paper proposes PriorityMAC, a priority-enhanced medium access control protocol, designed for critical traffic in industrial wireless sensor and actuator networks (IWSAN). A notable trend in industrial automation in recent years has been the replacement of wired communication by IWSANs. Exceeding the required delay bound for unpredictable and emergency traffic could lead to system instability, economic and material losses, system failure, and, ultimately, a threat to human safety. Guaranteeing the timely delivery of the IWSAN critical traffic and its prioritization over regular traffic (e.g., noncritical monitoring traffic) is a significant challenge. Therefore, we present the design, implementation, performance analysis, and evaluation of PriorityMAC. A series of novel mechanisms (e.g., high priority indication space) are proposed to enable high-priority traffic to hijack the transmission bandwidth of the low-priority traffic. To the best of our knowledge, this is the first priority-enhanced MAC protocol compatible with industrial standards for IWSAN. PriorityMAC is implemented in TinyOS and evaluated on a testbed of Telosb motes. The experimental results indicate that PriorityMAC efficiently handles different traffic categories with different latency requirements, thereby achieving a significant improvement in the delivery latency compared with the current industrial standards.

PriorityMAC: A Priority-Enhanced MAC Protocol for Critical Traffic in Industrial Wireless Sensor and Actuator Networks

A secure communications and location authorization system using a power line or a potion thereof as a side-channel that mitigates man-in-the-middle attacks on communications networks and devices connected to those networks. The system includes a power grid server associated with a substation, or curb-side distribution structure such as a transformer, an electric meter associated with a structure having electric service and able to communicate with the power grid server, a human authorization detector input device connected to the electric meter and the power grid server. The human authorization detector is able to receive an input from a user physically located at the structure and capable of communicating with the power grid server via the electric meter. The user's physical input into the device causing a request to be sent to the power grid server that then generates a location certificate for the user. Without the location certificate, access to the communications network and devices connected to those networks can be denied.

System, method, and apparata for secure communications using an electrical grid network

The availability of small inexpensive sensor elements enables the employment of large wired or wireless sensor networks for feeding control systems. Unfortunately, the need to transmit a large number of sensor measurements over a network negatively affects the timing parameters of the control loop. This paper presents a solution to this problem by representing sensor measurements with an approximate representation-an interpolation of sensor measurements as a function of space coordinates. A priority-based medium access control (MAC) protocol is used to select the sensor messages with high information content. Thus, the information from a large number of sensor measurements is conveyed within a few messages. This approach greatly reduces the time for obtaining a snapshot of the environment state and therefore supports the real-time requirements of feedback control loops.

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A Scalable and Efficient Approach for Obtaining Measurements in CAN-Based Control Systems

In this paper we describe how to integrate Internet Protocols (IP) into a typical hierarchical master-slave fieldbus network, supporting a logical ring token passing mechanism between master stations. The integration of the TCP/IP protocols in the fieldbus protocol rises a number of issues that must be addressed properly. In this paper we particularly address the issues related to the conveyance of IP fragments in fieldbus frames (fragmentation/defragmentation) and on how to support the symmetry inherent to the TCP/IP protocols in fieldbus slaves, which lack communication initiative.

/pdf/supporting-internet-protocols-in-master-slave-fieldbus-r3y7o0le9v.pdf

Supporting Internet Protocols in Master-Slave Fieldbus Networks

Although power-line communication (PLC) is not a new technology, its use to support data communication with timing requirements is still the focus of ongoing research. A new infrastructure intended for communication using power lines from a central location to dispersed nodes using inexpensive devices was presented recently. This new infrastructure uses a two-level hierarchical power-line system, together with an IP-based network. Due to the master-slave behaviour of the PLC medium access, together with the inherent dynamic topology of power-line networks, a mechanism to provide end-to-end communication through the two levels of the power-line system must be provided. In this paper we introduce the architecture of the PLC protocol layer that is being implemented for this end

https://www.cister.isep.ipp.pt/docs/queuing_and_routing_in_a_hierarchical_powerline_communication_system/224/view.pdf

Queuing and routing in a hierarchical powerline communication system

Recent technological developments are pulling fieldbus networks to support a new wide class of applications, such as industrial multimedia applications These applications are usually supported by the widely used TCP/IP stack It is thus essential to provide support to TCP/IP based applications, in fieldbus networks This paper presents an effort that is being carried out to integrate the TCP/IP and PROFIBUS stacks, in order to support industrial multimedia applications, whilst guarantying the timing requirements of control-related traffic

/pdf/integration-of-tcp-ip-and-profibus-protocols-1fj5oz152e.pdf

Integration of TCP/IP and PROFIBUS Protocols

In this paper we describe a real-time industrial communication network able to support both controlrelated and multimedia traffic. The industrial communication network is based on the PROFIBUS standard, with multimedia capabilities being provided by an adequate integration of TCP/IP protocols into the PROFIBUS stack. From the operational point of view the integration of TCP/IP into PROFIBUS is by itself a challenge, since the master-slave nature of the PROFIBUS MAC makes complex the implementation of the symmetry inherent to IP communications. From the timeliness point of view the challenge is two folded. On one hand the multimedia traffic should not interfere with the timing requirements of the "native" control-related PROFIBUS traffic (typically hard real-time). On the other hand multimedia traffic requires certain levels of quality-of-service to be attained. In this paper we provide a methodology that enables fulfilling the timing requirements for both types of traffic in these real-time industrial LAN. Moreover, we describe suitable algorithms for the scheduling support of concurrent multimedia streams.

/pdf/industrial-multimedia-over-factory-floor-networks-3016mlqebh.pdf

Filipe Pacheco

Papers

A Scalable and Efficient Approach for Obtaining Measurements in CAN-Based Control Systems

Supporting Internet Protocols in Master-Slave Fieldbus Networks

Queuing and routing in a hierarchical powerline communication system

Integration of TCP/IP and PROFIBUS Protocols

Industrial Multimedia over Factory-Floor Networks