Mahesh Sooriyabandara

Smart Grid Communications: Overview of Research Challenges, Solutions, and Standardization Activities

Optimization of energy consumption in future intelligent energy networks (or Smart Grids) will be based on grid-integrated near-real-time communications between various grid elements in generation, transmission, distribution and loads. This paper discusses some of the challenges and opportunities of communications research in the areas of smart grid and smart metering. In particular, we focus on some of the key communications challenges for realizing interoperable and future-proof smart grid/metering networks, smart grid security and privacy, and how some of the existing networking technologies can be applied to energy management. Finally, we also discuss the coordinated standardization efforts in Europe to harmonize communications standards and protocols.

Low Power Wide Area Networks: An Overview

Low power wide area (LPWA) networks are attracting a lot of attention primarily because of their ability to offer affordable connectivity to the low-power devices distributed over very large geographical areas. In realizing the vision of the Internet of Things, LPWA technologies complement and sometimes supersede the conventional cellular and short range wireless technologies in performance for various emerging smart city and machine-to-machine applications. This review paper presents the design goals and the techniques, which different LPWA technologies exploit to offer wide-area coverage to low-power devices at the expense of low data rates. We survey several emerging LPWA technologies and the standardization activities carried out by different standards development organizations (e.g., IEEE, IETF, 3GPP, ETSI) as well as the industrial consortia built around individual LPWA technologies (e.g., LoRa Alliance, Weightless-SIG, and Dash7 alliance). We further note that LPWA technologies adopt similar approaches, thus sharing similar limitations and challenges. This paper expands on these research challenges and identifies potential directions to address them. While the proprietary LPWA technologies are already hitting the market with large nationwide roll-outs, this paper encourages an active engagement of the research community in solving problems that will shape the connectivity of tens of billions of devices in the next decade.

Reinforcement learning based spectrum-aware routing in multi-hop cognitive radio networks

Routing in multi-hop cognitive radio networks (CRN) should be spectrum-aware. In this paper, two adaptive reinforcement learning based spectrum-aware routing protocols are introduced. Q-Learning and Dual Reinforcement Learning are applied respectively for them. The cognitive nodes store a table of Q values that estimate the numbers of available channels on the routes and update them while routing. So they can adaptively learn good routes which have more available channels from just local information. Compared to the previous spectrumaware routing protocols in multi-hop cognitive radio networks, they are simpler and easier to implement, more cost-effective, and can avoid drawbacks in on-demand protocols but still keep adaptive and dynamic routing. Both of our protocols perform better than the spectrum-aware shortest path protocol when network load is not too low. In the meantime, spectrum-aware DRQ-routing learns the optimal routing policy 1.5 times as fast as the spectrum-aware Q-routing at low and medium network load. It also learns a routing policy which is more than seven times as good as that of spectrum-aware Q-routing at high network load.

Challenges of real-time secondary usage of spectrum

In this survey paper, we investigate some of the challenges to be addressed before a practical real-time secondary market for spectrum can be developed. We differentiate the methods of dynamic spectrum allocation as coordinated usage of resources, interworking solutions, integration solutions and secondary access of spectrum. Secondary spectrum access approaches are generally classified as real-time and non-real-time secondary access. However, the focus of this work is on real-time secondary spectrum utilization which can follow a negotiated or opportunistic access strategy. While different solutions for increasing spectrum utilization and efficiency are under investigation, many aspects of spectrum sharing technologies are still open questions. After an extensive literature survey, the major challenges and open questions of real-time secondary usage of spectrum are addressed here. We also provide some insights on potentially important design considerations and requirements when developing successful spectrum management schemes to realize real-time secondary spectrum usage.

M2M Communications in the Smart Grid: Applications, Standards, Enabling Technologies, and Research Challenges

We present some of the ongoing standardisation work in M2M communications followed by the application of machine-to-machine (M2M) communications to smart grid. We analyse and discuss the enabling technologies in M2M and present an overview of the communications challenges and research opportunities with a focus on wireless sensor networks and their applications in a smart grid environment.

Unified Link Layer API: A generic and open API to manage wireless media access

We present the Unified Link Layer API (ULLA) framework: an open and extensible API framework that incorporates a number of requirements related to a wide range of applications, including multi-mode and cross-layer optimisation scenarios. This work has been mainly motivated by the complexity and interoperability problems related to the large number of wireless APIs available today. ULLA provides database and object oriented service abstractions to applications through a generic query mechanism, a method to setup asynchronous notifications and a command interface. It encapsulates link level heterogeneity by defining a unified model for link technologies. We describe design details, various implementation options and discuss how the proposed ULLA design provides an extensible, scalable and platform independent framework, enabling seamless link access and control in various types of device platforms. Application programming using ULLA is illustrated using code examples. Numerous usage scenarios for ULLA are presented, highlighting unified access to heterogeneous link standards while encouraging application innovation.

Toward Unified Security and Privacy Protection for Smart Meter Networks

The management of security and privacy protection mechanisms is one fundamental issue of future smart grid (SG) and metering networks. Designing effective and economical measures is a nontrivial task due to the following: 1) the large number of system requirements; and 2) the uncertainty over how the system functionalities are going to be specified and to evolve. This paper explores a unified approach for addressing security and privacy of smart metering (SM) systems. In the process, we present a unified framework that entails the analysis and synthesis of security solutions associated with closely interrelated components of a typical SM system. Ultimately, the proposed framework can be used as a guideline for embedding cross-domain security and privacy solutions into SG communication systems.

Smart Grid - Technologies for its realisation

There is a growing interest towards the development of the Smart Grid. Even though the Smart Grid offers many advantages for the connection of renewable energy sources while providing the efficient operation of the power grid, there are many gray areas which delay its realization. It is recognized that the early realization of the Smart Grid requires standards and regulations that ensures interoperability, security and privacy of information, protocols that ensures communications across heterogeneous networks. Further, achieving smart grid goals of improving energy efficiency, reliable energy delivery, living-standard with novel applications and market services will require significant innovation well beyond engineering of existing technologies. This paper identifies enabling technology areas for Smart Grid and presents key engineering and research challenges in the communications technology area.

Cost optimization of smart appliances

A control method of smart appliances, as part of home automation, is simulated. An optimization technique, binary integer programming, is employed to solve the scheduling of smart appliances. The cost savings achieved by interrupting the cycle of smart appliances has been explored within the optimisation suite. The home automation controller is using price signals made available by smart meters to shift and interrupt smart appliances in order to maximise the benefits for the residential consumers. Results show that the described optimisation can be used in home automation for cost savings while allowing users different levels of control on the smart appliances. A case study carried out with three smart appliances shows substantial cost savings under real time pricing.

Enhancing multimedia streaming over existing wireless LAN technology using the unified link layer API

This paper examines how multimedia streaming scenarios can be enhanced by cross-layer interaction, and in particular link performance information and configuration options provided by the recently developed Unified Link Layer API (ULLA). It provides results of an experimental implementation developed for this purpose in a wireless LAN (WLAN) environment. Multimedia streaming is an application that is gaining in popularity for mobile devices and in particular mobile Internet-based content broadcasting is rapidly emerging as a key feature on mobile devices. In these scenarios, the wireless link (last hop) is normally the performance bottleneck due to the dynamic and limited capacity of the wireless medium. The use of ULLA in this context can provide the ability to tailor the video transmission to the wireless link performance and also to configure the links in response to performance problems or environmental changes. For this purpose the focus of multimedia streaming has been on WLAN link technology and dynamic adaptation (i.e., dynamic channel selection and video transcoding) using a dynamic resource reservation overlay protocol.