Costas Efthymiou

Smart Grid Privacy via Anonymization of Smart Metering Data

The security and privacy of future smart grid and smart metering networks is important to their rollout and eventual acceptance by the public: research in this area is ongoing and smart meter users will need to be reassured that their data is secure. This paper describes a method for securely anonymizing frequent (for example, every few minutes) electrical metering data sent by a smart meter. Although such frequent metering data may be required by a utility or electrical energy distribution network for operational reasons, this data may not necessarily need to be attributable to a specific smart meter or consumer. It does, however, need to be securely attributable to a specific location (e.g. a group of houses or apartments) within the electricity distribution network. The method described in this paper provides a 3rd party escrow mechanism for authenticated anonymous meter readings which are difficult to associate with a particular smart meter or customer. This method does not preclude the provision of attributable metering data that is required for other purposes such as billing, account management or marketing research purposes.

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.

Privacy for Smart Meters: Towards Undetectable Appliance Load Signatures

Smart grid privacy encompasses the privacy of information extracted by analysing smart metering data. In this paper, we suggest that home electrical power routing can be used to moderate the homes load signature in order to hide appliance usage information. In particular, 1) we introduce a power management model using a rechargeable battery, 2) we propose a power mixing algorithm, and 3) we evaluate its protection level by proposing three different privacy metrics: an information theoretic (relative entropy), a clustering classification, and a correlation/regression one; these are tested on different metering datasets. This paper sets the ground for further research on the subject of optimising home energy management with regards to hiding load signatures.

ElecPrivacy: Evaluating the Privacy Protection of Electricity Management Algorithms

The data collected by a home smart meter can potentially reveal sensitive private information about the home resident(s). In this paper, we study how home energy resources can be used to protect the privacy of the collected data. In particular we: a) introduce a power mixing algorithm to selectively protect a set of consumption events; b) develop a range of different privacy protection metrics; c) analyze real smart metering data sampled twice a minute over a period of 13 days; and d) evaluate the protection offered by different power mixing algorithms. Major factors which determine the efficiency of the proposed power mixing algorithms are identified, such as battery capacity and power, and user preferences for privacy-based allocations of battery energy quotas.

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.

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.

Terminal Centric Optimisation for the Wireless Local Area

There is growing interest within industry and standardisation bodies to permit wireless local area networks to utilise the scarce radio resources more efficiently and intelligently. One approach is to increase the physical layer data rate and exploit multi-path and spatial diversity using multi antenna systems, the other, and complementary, approach is to use more intelligent dynamic channel and mode selection. Both approaches are inter-related, but in this paper we focus on techniques for the latter. In particular we address the dynamic channel and mode selection problem from a terminal point of view and have implemented a solution that provides significant performance enhancements over conventional techniques when applied to existing wireless local area networks.

Application of multiple-wireless to a visual localisation system for emergency services

In this paper we discuss the application of multiple-wireless technology to a practical context-enhanced service system called ViewNet. ViewNet develops technologies to support enhanced coordination and cooperation between operation teams in the emergency services and the police. Distributed localisation of users and mapping of environments implemented over a secure wireless network enables teams of operatives to search and map an incident area rapidly and in full coordination with each other and with a control centre. Sensing is based on fusing absolute positioning systems (UWB and GPS) with relative localisation and mapping from on-body or hand-held vision and inertial sensors. This paper focuses on the case for multiple-wireless capabilities in such a system and the benefits it can provide. We describe our work of developing a software API to support both WLAN and TETRA in ViewNet. It also provides a basis for incorporating future wireless technologies into ViewNet.

A new differential resource reservation protocol to support adaptive multimedia applications on heterogeneous networks

The recent proliferation of mobile communications systems has gone unnoticed by none and the encapsulation of voice and data services within a single framework is imminent. Future applications and devices demands that full quality of service (QoS) flexibility be available to them at all times. QoS provision for mobile networks is a difficult affair with numerous research efforts abounding in this area. The instability of the radio channel makes bandwidth adaptation unpredictable; consequently a mechanism is needed that enables fast adaptation at the radio layer whilst allowing the network to follow this adaptation in its own way. We present an adaptive extension to RSVP, differential RSVP, which provides this mechanism. Features of this protocol include traffic specification with bandwidth granularity (for layered source coding applications) and independent frequency of adaptation for each node along a network path.